Vasopressin
Encyclopedia
Arginine vasopressin also known as vasopressin, argipressin or antidiuretic hormone (ADH), is a neurohypophysial hormone
found in most mammals, including humans. Vasopressin is a peptide hormone
that controls the reabsorption of molecules in the tubules of the kidneys by affecting the tissue's permeability. It also increases peripheral vascular resistance, which in turn increases arterial blood pressure
. It plays a key role in homeostasis
, and the regulation of water, glucose, and salts in the blood. It is derived from a preprohormone
precursor that is synthesized in the hypothalamus
and stored in vesicles at the posterior pituitary
. Most of it is stored in the posterior pituitary to be released into the bloodstream; however, some AVP is also released directly into the brain
, where it plays an important role in social behavior
and bonding.
; it is released when the body is dehydrated and causes the kidney
s to conserve water, thus concentrating the urine
, and reducing urine volume. In high concentrations, it also raises blood pressure by inducing moderate vasoconstriction
. In addition, it has a variety of neurological effects on the brain, having been found, for example, to influence pair-bonding in voles. The high-density distributions of vasopressin receptor AVPr1a in prairie vole
ventral forebrain regions have been shown to facilitate and coordinate reward circuits during partner preference formation, critical for pair bond formation.
A very similar substance, lysine vasopressin (LVP) or lypressin, has the same function in pig
s and is often used in human therapy.
1.) Increasing the water permeability of distal tubule and collecting duct cells in the kidney, thus allowing water reabsorption and excretion of more concentrated urine, i.e., antidiuresis
. This occurs through insertion of water channels (Aquaporin-2
) into the apical membrane of distal tubule and collecting duct epithelial cells. Aquaporins allow water to move down their osmotic gradient and out of the nephron, increasing the amount of water re-absorbed from the filtrate (forming urine) back into the bloodstream.
V2 receptors, which are G protein-coupled receptor
s on the basolateral plasma membrane of the epithelial cells, couple to the heterotrimeric G-protein Gs
, which activates adenylyl cyclases III and VI to convert ATP
into cAMP
, plus 2 inorganic phosphates. The rise in cAMP then triggers the insertion of aquaporin-2 water channels by exocytosis of intracellular vesicles, recycling endosomes. Vasopressin also increases the concentration of calcium in the collecting duct cells, by episodic release from intracellular stores. Vasopressin, acting through cAMP, also increases transcription of the aquaporin-2 gene, thus increasing the total number of aquaporin-2 molecules in collecting duct cells.
Cyclic-AMP activates protein kinase A (PKA) by binding to its regulatory subunits and allowing them to detach from the catalytic subunits. Detachment exposes the catalytic site in the enzyme, allowing it to add phosphate groups to proteins (including the aquaporin-2 protein), which alters their functions.
2.) Increasing permeability of the inner medullary portion of the collecting duct to urea
by regulating the cell surface expression of urea transporter
s, which facilitates its reabsorption into the medullary interstitium
as it travels down the concentration gradient created by removing water from the connecting tubule
, cortical collecting duct, and outer medullary collecting duct.
. This effect appears small in healthy individuals; however it becomes an important compensatory mechanism for restoring blood pressure in hypovolemic shock such as that which occurs during hemorrhage.
In recent years, there has been particular interest in the role of vasopressin in social behavior. It is thought that vasopressin, released into the brain during sexual activity, initiates and sustains patterns of activity that support the pair-bond between the sexual partners; in particular, vasopressin seems to induce the male to become aggressive towards other males.
Evidence for this comes from experimental studies in several species, which indicate that the precise distribution of vasopressin and vasopressin receptors in the brain is associated with species-typical patterns of social behavior. In particular, there are consistent differences between monogamous species and promiscuous species in the distribution of AVP receptors, and sometimes in the distribution of vasopressin-containing axons, even when closely related species are compared. Moreover, studies involving either injecting AVP agonists into the brain or blocking the actions of AVP support the hypothesis that vasopressin is involved in aggression towards other males. There is also evidence that differences in the AVP receptor gene between individual members of a species might be predictive of differences in social behavior.
One study has suggested that genetic variation in male humans effects pair-bonding behavior. The brain of males uses vasopressin as a reward for forming lasting bonds with a mate, and men with one or two of the genetic alleles are more likely to experience marital discord. The partners of the men with two of the alleles affecting vasopressin reception state disappointing levels of satisfaction, affection, and cohesion.
Vasopressin receptors distributed along the reward circuit pathway, to be specific in the ventral pallidum, are activated when AVP is released during social interactions such as mating, in monogamous prairie voles. The activation of the reward circuitry reinforces this behavior, leading to conditioned partner preference, and thereby initiates the formation of a pair bond.
volume, in response to increases in the plasma osmolality
, and in response to cholecystokinin
secreted by the small intestine
:
The neurons that make AVP, in the hypothalamic supraoptic nuclei
(SON) and paraventricular nuclei
(PVN), are themselves osmoreceptors, but they also receive synaptic input from other osmoreceptors located in regions adjacent to the anterior wall of the third ventricle. These regions include the organum vasculosum of the lamina terminalis
and the subfornical organ
.
Many factors influence the secretion of vasopressin:
The AVP that is measured in peripheral blood is almost all derived from secretion from the posterior pituitary gland (except in cases of AVP-secreting tumours). However there are two other sources of AVP with important local effects:
s consisting of nine amino acid
s (nonapeptides). (NB: the value in the table above of 164 amino acids is that obtained before the hormone is activated by cleavage). The amino acid sequence of arginine vasopressin is Cys
-Tyr
-Phe
-Gln
-Asn
-Cys
-Pro
-Arg
-Gly
, with the cysteine residues forming a sulfur bridge. Lysine vasopressin has a lysine
in place of the arginine.
The structure of oxytocin
is very similar to that of the vasopressins: It is also a nonapeptide with a disulfide bridge and its amino acid sequence differs at only two positions (see table below). The two genes are located on the same chromosome separated by a relatively small distance of less than 15,000 bases in most species. The magnocellular neurons
that make vasopressin are adjacent to magnocellular neurons that make oxytocin, and are similar in many respects.
The similarity of the two peptides can cause some cross-reactions: oxytocin has a slight antidiuretic function, and high levels of AVP can cause uterine contractions.
Here is a table showing the superfamily of vasopressin and oxytocin neuropeptides:
, a condition featuring hypernatremia
(increased blood sodium
concentration), polyuria
(excess urine production), and polydipsia
(thirst).
High levels of AVP secretion (syndrome of inappropriate antidiuretic hormone
, SIADH) and resultant hyponatremia
(low blood sodium levels) occurs in brain
diseases and conditions of the lung
s (Small cell lung carcinoma). In the perioperative
period, the effects of surgical stress and some commonly used medications (e.g., opiates, syntocinon, anti-emetics) lead to a similar state of excess vasopressin secretion. This may cause mild hyponatremia for several days.
Hyponatremia can be treated pharmaceutically through the use of vasopressin receptor antagonist
s. These include the approved drug Vaprisol and the phase III drug lixivaptan
.
is used in conditions featuring low vasopressin secretion, as well as for control of bleeding (in some forms of von Willebrand disease
and in mild haemophilia A
) and in extreme cases of bedwetting by children. Terlipressin
and related analogues are used as vasoconstrictors in certain conditions. Use of vasopressin analogues for esophageal varices
commenced in 1970.
Vasopressin infusion has been used as a second line of management in septic shock
patients not responding to high dose of inotrope
s (e.g., dopamine
or norepinephrine
). It had been shown to be more effective than epinephrine in asystolic
cardiac arrest
. While not all studies are in agreement, a 2006 study of out-of hospital cardiac arrests has added to the evidence for the superiority of AVP in this situation, but these studies relied on sub-group analysis and better designed prospective studies show no benefit in ACLS.
is an agent that interferes with action at the vasopressin receptor
s. They can be used in the treatment of hyponatremia
.
Neurohypophysial hormone
Neurohypophysial hormones is a family of structurally and functionally related peptide hormones that includes oxytocin and vasopressin.Hypophysis refers to the pituitary gland....
found in most mammals, including humans. Vasopressin is a peptide hormone
Peptide hormone
Peptide hormones are a class of peptides that are secreted into the blood stream and have endocrine functions in living animals.Like other proteins, peptide hormones are synthesized in cells from amino acids according to an mRNA template, which is itself synthesized from a DNA template inside the...
that controls the reabsorption of molecules in the tubules of the kidneys by affecting the tissue's permeability. It also increases peripheral vascular resistance, which in turn increases arterial blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
. It plays a key role in homeostasis
Homeostasis
Homeostasis is the property of a system that regulates its internal environment and tends to maintain a stable, constant condition of properties like temperature or pH...
, and the regulation of water, glucose, and salts in the blood. It is derived from a preprohormone
Preprohormone
A preprohormone is the precursor protein to one or more prohormones, which are in turn precursors to peptide hormones. The protein generally consists of the amino acid chain that is created by the hormone secreting cell, before any changes have been made to it. It contains a signal peptide, the...
precursor that is synthesized in the hypothalamus
Hypothalamus
The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...
and stored in vesicles at the posterior pituitary
Posterior pituitary
The posterior pituitary comprises the posterior lobe of the pituitary gland and is part of the endocrine system. Despite its name, the posterior pituitary gland is not a gland, per se; rather, it is largely a collection of axonal projections from the hypothalamus that terminate behind the anterior...
. Most of it is stored in the posterior pituitary to be released into the bloodstream; however, some AVP is also released directly into the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
, where it plays an important role in social behavior
Social behavior
In physics, physiology and sociology, social behavior is behavior directed towards society, or taking place between, members of the same species. Behavior such as predation which involves members of different species is not social...
and bonding.
Function
One of the most important roles of AVP is to regulate the body's retention of waterWater retention (medicine)
The term water retention signifies an abnormal accumulation of fluid in the circulatory system or within the tissues or cavities of the body.Water is found both inside and outside the body’s cells...
; it is released when the body is dehydrated and causes the kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
s to conserve water, thus concentrating the urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
, and reducing urine volume. In high concentrations, it also raises blood pressure by inducing moderate vasoconstriction
Vasoconstriction
Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries, small arterioles and veins. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in...
. In addition, it has a variety of neurological effects on the brain, having been found, for example, to influence pair-bonding in voles. The high-density distributions of vasopressin receptor AVPr1a in prairie vole
Prairie Vole
The Prairie Vole is a small vole found in central North America. The vole has long, coarse grayish-brown fur on the upper portion of the body and yellowish fur on the lower portion of the body...
ventral forebrain regions have been shown to facilitate and coordinate reward circuits during partner preference formation, critical for pair bond formation.
A very similar substance, lysine vasopressin (LVP) or lypressin, has the same function in pig
Pig
A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...
s and is often used in human therapy.
Kidney
Vasopressin has two effects by which it contributes to increased urine osmolality (increased concentration) and decreased water excretion. These are:1.) Increasing the water permeability of distal tubule and collecting duct cells in the kidney, thus allowing water reabsorption and excretion of more concentrated urine, i.e., antidiuresis
Antidiuretic
An antidiuretic is an agent or drug that, administered to an organism, helps control body water balance by reducing urination, opposing diuresis.-Uses:...
. This occurs through insertion of water channels (Aquaporin-2
Aquaporin
Aquaporins are proteins embedded in the cell membrane that regulate the flow of water.Aquaporins are integral membrane proteins from a larger family of major intrinsic proteins that form pores in the membrane of biological cells....
) into the apical membrane of distal tubule and collecting duct epithelial cells. Aquaporins allow water to move down their osmotic gradient and out of the nephron, increasing the amount of water re-absorbed from the filtrate (forming urine) back into the bloodstream.
V2 receptors, which are G protein-coupled receptor
G protein-coupled receptor
G protein-coupled receptors , also known as seven-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptor, and G protein-linked receptors , comprise a large protein family of transmembrane receptors that sense molecules outside the cell and activate inside signal...
s on the basolateral plasma membrane of the epithelial cells, couple to the heterotrimeric G-protein Gs
Gs alpha subunit
The Gs alpha subunit is a heterotrimeric G protein subunit that activates the cAMP-dependent pathway by activating adenylate cyclase.-Receptors:The G protein-coupled receptors that couple to this kind of G-protein include:...
, which activates adenylyl cyclases III and VI to convert ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
into cAMP
Cyclic adenosine monophosphate
Cyclic adenosine monophosphate is a second messenger important in many biological processes...
, plus 2 inorganic phosphates. The rise in cAMP then triggers the insertion of aquaporin-2 water channels by exocytosis of intracellular vesicles, recycling endosomes. Vasopressin also increases the concentration of calcium in the collecting duct cells, by episodic release from intracellular stores. Vasopressin, acting through cAMP, also increases transcription of the aquaporin-2 gene, thus increasing the total number of aquaporin-2 molecules in collecting duct cells.
Cyclic-AMP activates protein kinase A (PKA) by binding to its regulatory subunits and allowing them to detach from the catalytic subunits. Detachment exposes the catalytic site in the enzyme, allowing it to add phosphate groups to proteins (including the aquaporin-2 protein), which alters their functions.
2.) Increasing permeability of the inner medullary portion of the collecting duct to urea
Urea
Urea or carbamide is an organic compound with the chemical formula CO2. The molecule has two —NH2 groups joined by a carbonyl functional group....
by regulating the cell surface expression of urea transporter
Urea transporter
An urea transporter is a membrane transport protein, transporting urea. Humans and other mammals have two types of urea transport proteins, UT-A and UT-B. The UT-A proteins are important for renal urea handling and are produced by alternative splicing of the SLC14A2 gene...
s, which facilitates its reabsorption into the medullary interstitium
Medullary interstitium
The medullary interstitium is the tissue surrounding the loop of Henle in the renal medulla.It functions in renal water reabsorption by building up a high hypertonicity, which draws water out of the thin descending limb of the loop of Henle and the collecting duct system. This hypertonicity, in...
as it travels down the concentration gradient created by removing water from the connecting tubule
Connecting tubule
In the kidney, the collecting tubule is a tubular segment of the renal collecting duct system that connects the distal convoluted tubule to the cortical collecting duct.-Classification:...
, cortical collecting duct, and outer medullary collecting duct.
Cardiovascular system
Vasopressin increases peripheral vascular resistance (vasoconstriction) and thus increases arterial blood pressureBlood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
. This effect appears small in healthy individuals; however it becomes an important compensatory mechanism for restoring blood pressure in hypovolemic shock such as that which occurs during hemorrhage.
Central nervous system
Vasopressin released within the brain has many actions:- It has been implicated in memoryMemoryIn psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....
formation, including delayed reflexes, image, short- and long-term memory, though the mechanism remains unknown; these findings are controversial. However, the synthetic vasopressin analogueVasopressin analogueVasopressin analogues are chemicals similar in function but not necessarily similar in structure to vasopressin , such as desmopressin....
desmopressinDesmopressinDesmopressin is a synthetic replacement for vasopressin, the hormone that reduces urine production. It may be taken nasally, intravenously, or as a tablet...
has come to interest as a likely nootropicNootropicNootropics , also referred to as smart drugs, brain steroids, memory enhancers, cognitive enhancers, and intelligence enhancers, are drugs, supplements, nutraceuticals, and functional foods that improve mental functions such as cognition, memory, intelligence, motivation, attention, and concentration...
.
- Vasopressin is released into the brain in a circadian rhythmCircadian rhythmA circadian rhythm, popularly referred to as body clock, is an endogenously driven , roughly 24-hour cycle in biochemical, physiological, or behavioural processes. Circadian rhythms have been widely observed in plants, animals, fungi and cyanobacteria...
by neurons of the supraoptic nucleusSupraoptic nucleusThe supraoptic nucleus is a nucleus of magnocellular neurosecretory cells in the hypothalamus of the mammalian brain. The nucleus is situated at the base of the brain, adjacent to the optic chiasm...
.
- Vasopressin released from centrally projecting hypothalamic neurons is involved in aggression, blood pressure regulation and temperature regulation.
- Selective AVPr1a blockade in the ventral pallidumVentral pallidumThe Ventral Pallidum is a structure within the basal ganglia of the brain. It is an output nucleus whose fibres project to thalamic nuclei, such as the ventral anterior nucleus, the ventrolateral nucleus, and the medial dorsal nucleus....
has been shown to prevent partner preference, suggesting that these receptors in this ventral forebrain region are crucial for pair bonding.
In recent years, there has been particular interest in the role of vasopressin in social behavior. It is thought that vasopressin, released into the brain during sexual activity, initiates and sustains patterns of activity that support the pair-bond between the sexual partners; in particular, vasopressin seems to induce the male to become aggressive towards other males.
Evidence for this comes from experimental studies in several species, which indicate that the precise distribution of vasopressin and vasopressin receptors in the brain is associated with species-typical patterns of social behavior. In particular, there are consistent differences between monogamous species and promiscuous species in the distribution of AVP receptors, and sometimes in the distribution of vasopressin-containing axons, even when closely related species are compared. Moreover, studies involving either injecting AVP agonists into the brain or blocking the actions of AVP support the hypothesis that vasopressin is involved in aggression towards other males. There is also evidence that differences in the AVP receptor gene between individual members of a species might be predictive of differences in social behavior.
One study has suggested that genetic variation in male humans effects pair-bonding behavior. The brain of males uses vasopressin as a reward for forming lasting bonds with a mate, and men with one or two of the genetic alleles are more likely to experience marital discord. The partners of the men with two of the alleles affecting vasopressin reception state disappointing levels of satisfaction, affection, and cohesion.
Vasopressin receptors distributed along the reward circuit pathway, to be specific in the ventral pallidum, are activated when AVP is released during social interactions such as mating, in monogamous prairie voles. The activation of the reward circuitry reinforces this behavior, leading to conditioned partner preference, and thereby initiates the formation of a pair bond.
Control
Vasopressin is secreted from the posterior pituitary gland in response to reductions in plasmaBlood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
volume, in response to increases in the plasma osmolality
Plasma osmolality
-Measured osmolality :Osmolality can be measured on an analytical instrument called an osmometer. It works on the method of depression of freezing point.Plasma osmolality is affected by changes in water content...
, and in response to cholecystokinin
Cholecystokinin
Cholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein...
secreted by the small intestine
Small intestine
The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...
:
- Secretion in response to reduced plasma volume is activated by pressure receptorsBaroreceptorBaroreceptors are sensors located in the blood vessels of several mammals. They are a type of mechanoreceptor that detects the pressure of blood flowing through them, and can send messages to the central nervous system to increase or decrease total peripheral resistance and cardiac output...
in the veinVeinIn the circulatory system, veins are blood vessels that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart...
s, atriaAtrium (anatomy)In anatomy, the atrium , sometimes called auricle , refers to a chamber or space. For example, the term is used for a portion of the lateral ventricle in the brain and the blood collection chamber of the heart...
, and carotids. - Secretion in response to increases in plasma osmotic pressure is mediated by osmoreceptorOsmoreceptorAn osmoreceptor is a sensory receptor primarily found in the hypothalamus of most homeothermic organisms that detects changes in osmotic pressure. Osmoreceptors can be found in several structures, including the organum vasculosum of the lamina terminalis and the subfornical organ...
s in the hypothalamusHypothalamusThe Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...
. - Secretion in response to increases in plasma cholecystokininCholecystokininCholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein...
is mediated by an unknown pathway.
The neurons that make AVP, in the hypothalamic supraoptic nuclei
Supraoptic nucleus
The supraoptic nucleus is a nucleus of magnocellular neurosecretory cells in the hypothalamus of the mammalian brain. The nucleus is situated at the base of the brain, adjacent to the optic chiasm...
(SON) and paraventricular nuclei
Paraventricular nucleus
The paraventricular nucleus is a neuronal nucleus in the hypothalamus. It contains multiple subpopulations of neurons that are activated by a variety of stressful and/or physiological changes. Many PVN neurons project directly to the posterior pituitary where they release oxytocin or vasopressin...
(PVN), are themselves osmoreceptors, but they also receive synaptic input from other osmoreceptors located in regions adjacent to the anterior wall of the third ventricle. These regions include the organum vasculosum of the lamina terminalis
Organum vasculosum of the lamina terminalis
The organum vasculosum of the lamina terminalis is one of the circumventricular organs of the brain. Other circumventricular organs are the subfornical organ and the area postrema in the brainstem.-AV3V region:...
and the subfornical organ
Subfornical organ
The subfornical organ, situated on the ventral surface of the fornix, at the interventricular foramina , is one of the circumventricular organs of the brain.-Relations with other circumventricular organs:...
.
Many factors influence the secretion of vasopressin:
- EthanolEthanolEthanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
(alcohol) reduces the calcium-dependent secretion of AVP by blocking voltage-gated calcium channels in neurohypophyseal nerve terminals. - AngiotensinAngiotensinAngiotensin, a peptide hormone, causes blood vessels to constrict, and drives blood pressure up. It is part of the renin-angiotensin system, which is a major target for drugs that lower blood pressure. Angiotensin also stimulates the release of aldosterone, another hormone, from the adrenal cortex...
II stimulates AVP secretion, in keeping with its general pressor and pro-volemic effects on the body. - Atrial natriuretic peptideAtrial natriuretic peptideAtrial natriuretic peptide , atrial natriuretic factor , atrial natriuretic hormone , or atriopeptin, is a powerful vasodilator, and a protein hormone secreted by heart muscle cells. It is involved in the homeostatic control of body water, sodium, potassium and fat...
inhibits AVP secretion, in part by inhibiting Angiotensin II-induced stimulation of AVP secretion.
Secretion
The main stimulus for secretion of vasopressin is increased osmolality of plasma. Reduced volume of extracellular fluid also has this effect, but is a less sensitive mechanism.The AVP that is measured in peripheral blood is almost all derived from secretion from the posterior pituitary gland (except in cases of AVP-secreting tumours). However there are two other sources of AVP with important local effects:
- Vasopressin is produced by magnocellular neurons and parvocellular neurosecretory neurons in the PVN and SONSupraoptic nucleusThe supraoptic nucleus is a nucleus of magnocellular neurosecretory cells in the hypothalamus of the mammalian brain. The nucleus is situated at the base of the brain, adjacent to the optic chiasm...
. AVP produced by magnocellular neurons travels down the axon through the infundibulumPituitary stalkThe pituitary stalk is the connection between the hypothalamus and the posterior pituitary....
within neurosecretory granules that are found within Herring bodies, localized swellings of the axons and nerve terminals. These carry the peptide directly to the posterior pituitaryPosterior pituitaryThe posterior pituitary comprises the posterior lobe of the pituitary gland and is part of the endocrine system. Despite its name, the posterior pituitary gland is not a gland, per se; rather, it is largely a collection of axonal projections from the hypothalamus that terminate behind the anterior...
gland, where it is stored until released into the blood. AVP synthesized by parvocellular neurosecretory neurons at the PVN is released at the median eminenceMedian eminenceThe median eminence is part of the inferior boundary for the hypothalamus part of the human brain. A small swelling on the tuber cinereum posterior to the infundibulum - atop the pituitary stalk - the median eminence lies in the area roughly bounded on its posterolateral region by the cerebral...
which then travels through the Hypophyseal portal systemHypophyseal portal systemThe hypophyseal portal system is the system of blood vessels that link the hypothalamus and the anterior pituitary in the brain.It allows endocrine communication between the two structures. It is part of the hypothalamic-pituitary-adrenal axis. The anterior pituitary receives releasing and...
to the anterior pituitaryAnterior pituitaryA major organ of the endocrine system, the anterior pituitary, also called the adenohypophysis, is the glandular, anterior lobe of the pituitary gland...
where it stimulates corticotrope cells. - Vasopressin is also released into the brain by several different populations of smaller neurons (see below).
Receptors
Below is a table summarizing some of the actions of AVP at its four receptors, differently expressed in different tissues and exerting different actions:| Type | Second messenger system Second messenger system Second messengers are molecules that relay signals from receptors on the cell surface to target molecules inside the cell, in the cytoplasm or nucleus. They relay the signals of hormones like epinephrine , growth factors, and others, and cause some kind of change in the activity of the cell... |
Locations | Actions >- | AVPR1A Arginine vasopressin receptor 1A Arginine vasopressin receptor 1A is one of the three major receptor types for arginine vasopressin , and is present throughout the brain, as well as in the periphery in the liver, kidney, and vasculature.Arginine vasopressin receptor 1A is also known as:* V1a vasopressin receptor* antidiuretic... |
Phosphatidylinositol Phosphatidylinositol Phosphatidylinositol is a negatively charged phospholipid and a minor component in the cytosolic side of eukaryotic cell membranes.... /calcium Calcium Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust... |
Liver Liver The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion... , kidney Kidney The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and... , peripheral vasculature, brain Brain The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,... |
Vasoconstriction Vasoconstriction Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries, small arterioles and veins. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in... , gluconeogenesis Gluconeogenesis Gluconeogenesis is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as lactate, glycerol, and glucogenic amino acids.... , platelet Platelet Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days... aggregation, and release of factor VIII Factor VIII Factor VIII is an essential blood clotting factor also known as anti-hemophilic factor . In humans, Factor VIII is encoded by the F8 gene... and von Willebrand factor Von Willebrand factor von Willebrand factor is a blood glycoprotein involved in hemostasis. It is deficient or defective in von Willebrand disease and is involved in a large number of other diseases, including thrombotic thrombocytopenic purpura, Heyde's syndrome, and possibly hemolytic-uremic syndrome... ; social recognition, circadian tau >- | AVPR1B or AVPR3 Arginine vasopressin receptor 1B Arginine vasopressin receptor 1B is a protein that acts as receptor for arginine vasopressin. AVPR1B belongs to the subfamily of G-protein coupled receptors... |
Phosphatidylinositol Phosphatidylinositol Phosphatidylinositol is a negatively charged phospholipid and a minor component in the cytosolic side of eukaryotic cell membranes.... /calcium Calcium Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust... |
Pituitary gland Pituitary gland In vertebrate anatomy the pituitary gland, or hypophysis, is an endocrine gland about the size of a pea and weighing 0.5 g , in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity covered by a dural fold... , brain Brain The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,... |
Adrenocorticotropic hormone Adrenocorticotropic hormone Adrenocorticotropic hormone , also known as 'corticotropin', 'Adrenocorticotrophic hormone', is a polypeptide tropic hormone produced and secreted by the anterior pituitary gland. It is an important component of the hypothalamic-pituitary-adrenal axis and is often produced in response to biological... secretion in response to stress; social interpretation of olfactory cues >- | AVPR2 Arginine vasopressin receptor 2 Arginine vasopressin receptor 2 is a protein that acts as receptor for arginine vasopressin. AVPR2 belongs to the subfamily of G-protein-coupled receptors... |
Adenylate cyclase Adenylate cyclase Adenylate cyclase is part of the G protein signalling cascade, which transmits chemical signals from outside the cell across the membrane to the inside of the cell .... /cAMP Cyclic adenosine monophosphate Cyclic adenosine monophosphate is a second messenger important in many biological processes... |
Basolateral membrane of the cells lining the collecting ducts of the kidneys (especially the cortical and outer medullary collecting ducts) | Insertion of aquaporin-2 (AQP2) channels (water channels). This allows water to be reabsorbed down an osmotic gradient, and so the urine is more concentrated. Release of von Willebrand factor Von Willebrand factor von Willebrand factor is a blood glycoprotein involved in hemostasis. It is deficient or defective in von Willebrand disease and is involved in a large number of other diseases, including thrombotic thrombocytopenic purpura, Heyde's syndrome, and possibly hemolytic-uremic syndrome... and surface expression of P-selectin P-selectin P-selectin is a cell adhesion molecule on the surfaces of activated endothelial cells, which line the inner surface of blood vessels, and activated platelets... through exocytosis of Weibel-Palade bodies from endothelial cells |
| Phosphatidylinositol Phosphatidylinositol Phosphatidylinositol is a negatively charged phospholipid and a minor component in the cytosolic side of eukaryotic cell membranes.... /calcium Calcium Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust... |
Vascular endothelium Endothelium The endothelium is the thin layer of cells that lines the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. These cells are called endothelial cells. Endothelial cells line the entire circulatory system, from the heart... and renal collecting tubules |
Increases cytosolic calcium and acts as an inverse agonist of cAMP accumulation |
Structure and relation to oxytocin
The vasopressins are peptidePeptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
s consisting of nine amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s (nonapeptides). (NB: the value in the table above of 164 amino acids is that obtained before the hormone is activated by cleavage). The amino acid sequence of arginine vasopressin is Cys
Cysteine
Cysteine is an α-amino acid with the chemical formula HO2CCHCH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is polar and thus cysteine is usually classified as a hydrophilic amino acid...
-Tyr
Tyrosine
Tyrosine or 4-hydroxyphenylalanine, is one of the 22 amino acids that are used by cells to synthesize proteins. Its codons are UAC and UAU. It is a non-essential amino acid with a polar side group...
-Phe
Phenylalanine
Phenylalanine is an α-amino acid with the formula C6H5CH2CHCOOH. This essential amino acid is classified as nonpolar because of the hydrophobic nature of the benzyl side chain. L-Phenylalanine is an electrically neutral amino acid, one of the twenty common amino acids used to biochemically form...
-Gln
Glutamine
Glutamine is one of the 20 amino acids encoded by the standard genetic code. It is not recognized as an essential amino acid but may become conditionally essential in certain situations, including intensive athletic training or certain gastrointestinal disorders...
-Asn
Asparagine
Asparagine is one of the 20 most common natural amino acids on Earth. It has carboxamide as the side-chain's functional group. It is not an essential amino acid...
-Cys
Cysteine
Cysteine is an α-amino acid with the chemical formula HO2CCHCH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is polar and thus cysteine is usually classified as a hydrophilic amino acid...
-Pro
Proline
Proline is an α-amino acid, one of the twenty DNA-encoded amino acids. Its codons are CCU, CCC, CCA, and CCG. It is not an essential amino acid, which means that the human body can synthesize it. It is unique among the 20 protein-forming amino acids in that the α-amino group is secondary...
-Arg
Arginine
Arginine is an α-amino acid. The L-form is one of the 20 most common natural amino acids. At the level of molecular genetics, in the structure of the messenger ribonucleic acid mRNA, CGU, CGC, CGA, CGG, AGA, and AGG, are the triplets of nucleotide bases or codons that codify for arginine during...
-Gly
Glycine
Glycine is an organic compound with the formula NH2CH2COOH. Having a hydrogen substituent as its 'side chain', glycine is the smallest of the 20 amino acids commonly found in proteins. Its codons are GGU, GGC, GGA, GGG cf. the genetic code.Glycine is a colourless, sweet-tasting crystalline solid...
, with the cysteine residues forming a sulfur bridge. Lysine vasopressin has a lysine
Lysine
Lysine is an α-amino acid with the chemical formula HO2CCH4NH2. It is an essential amino acid, which means that the human body cannot synthesize it. Its codons are AAA and AAG....
in place of the arginine.
The structure of oxytocin
Oxytocin
Oxytocin is a mammalian hormone that acts primarily as a neuromodulator in the brain.Oxytocin is best known for its roles in sexual reproduction, in particular during and after childbirth...
is very similar to that of the vasopressins: It is also a nonapeptide with a disulfide bridge and its amino acid sequence differs at only two positions (see table below). The two genes are located on the same chromosome separated by a relatively small distance of less than 15,000 bases in most species. The magnocellular neurons
Magnocellular neurosecretory cell
Magnocellular neurosecretory cells are large cells within the supraoptic nucleus and paraventricular nucleus of the hypothalamus. They are also found in smaller numbers in accessory cell groups between these two nuclei, the largest one being the nucleus circularis...
that make vasopressin are adjacent to magnocellular neurons that make oxytocin, and are similar in many respects.
The similarity of the two peptides can cause some cross-reactions: oxytocin has a slight antidiuretic function, and high levels of AVP can cause uterine contractions.
Here is a table showing the superfamily of vasopressin and oxytocin neuropeptides:
| Vertebrate Vertebrate Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds... Vasopressin Family |
||
|---|---|---|
| Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-Gly-NH2 | Argipressin (AVP, ADH) | Most mammal Mammal Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young... s |
| Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Lys-Gly-NH2 | Lypressin (LVP) | Pig Pig A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives... s, hippos Hippopotamus The hippopotamus , or hippo, from the ancient Greek for "river horse" , is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest... , warthog Warthog The Warthog or Common Warthog is a wild member of the pig family that lives in grassland, savanna, and woodland in Sub-Saharan Africa. In the past it was commonly treated as a subspecies of P... s, some marsupial Marsupial Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central... s |
| Cys-Phe-Phe-Gln-Asn-Cys-Pro-Arg-Gly-NH2 | Phenypressin | Some marsupial Marsupial Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central... s |
| Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Arg-Gly-NH2 | Vasotocin Vasotocin Vasotocin is an oligopeptide hybrid of oxytocin and vasopressin found in all non-mammalian vertebrates including birds, fish, amphibians and in fetal mammals. In mammals it appears to have similar biological properties to both oxytocin and vasopressin... † |
Non-mammals |
| Vertebrate Oxytocin Family | ||
| Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2 | Oxytocin Oxytocin Oxytocin is a mammalian hormone that acts primarily as a neuromodulator in the brain.Oxytocin is best known for its roles in sexual reproduction, in particular during and after childbirth... (OXT) |
Most mammals, ratfish |
| Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Pro-Gly-NH2 | Prol-Oxytocin Oxytocin Oxytocin is a mammalian hormone that acts primarily as a neuromodulator in the brain.Oxytocin is best known for its roles in sexual reproduction, in particular during and after childbirth... |
Some New World monkeys New World monkey New World monkeys are the five families of primates that are found in Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Platyrrhini parvorder and the Ceboidea superfamily, which are essentially synonymous since... , northern tree shrews Northern Treeshrew The Northern Treeshrew is a species of treeshrew found in Southeast Asia.It was chosen as one of the 16 mammals to have their genomes sequenced by the Broad Institute, and a low coverage assembly of genome was released by the Broad Institute in June 2006. The genome will be useful in comparisons... |
| Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Ile-Gly-NH2 | Mesotocin | Most marsupials, all bird Bird Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from... s, reptile Reptile Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors... s, amphibian Amphibian Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods... s, lungfish Lungfish Lungfish are freshwater fish belonging to the Subclass Dipnoi. Lungfish are best known for retaining characteristics primitive within the Osteichthyes, including the ability to breathe air, and structures primitive within Sarcopterygii, including the presence of lobed fins with a well-developed... es, coelacanth Coelacanth Coelacanths are members of an order of fish that includes the oldest living lineage of Sarcopterygii known to date.... s |
| Cys-Tyr-Ile-Gln-Ser-Cys-Pro-Ile-Gly-NH2 | Seritocin | Frog Frog Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail... s |
| Cys-Tyr-Ile-Ser-Asn-Cys-Pro-Ile-Gly-NH2 | Isotocin | Bony fishes |
| Cys-Tyr-Ile-Ser-Asn-Cys-Pro-Gln-Gly-NH2 | Glumitocin | Skate Skate Skates are cartilaginous fish belonging to the family Rajidae in the superorder Batoidea of rays. There are more than 200 described species in 27 genera. There are two subfamilies, Rajinae and Arhynchobatinae .... s |
| Cys-Tyr-Ile-Asn/Gln-Asn-Cys-Pro-Leu/Val-Gly-NH2 | Various tocins | Shark Shark Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago.... s |
| Invertebrate Invertebrate An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group... VP/OT Superfamily |
||
| Cys-Leu-Ile-Thr-Asn-Cys-Pro-Arg-Gly-NH2 | Diuretic Hormone | Locust Locust Locusts are the swarming phase of short-horned grasshoppers of the family Acrididae. These are species that can breed rapidly under suitable conditions and subsequently become gregarious and migratory... |
| Cys-Phe-Val-Arg-Asn-Cys-Pro-Thr-Gly-NH2 | Annetocin | Earthworm Earthworm Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female... |
| Cys-Phe-Ile-Arg-Asn-Cys-Pro-Lys-Gly-NH2 | Lys-Connopressin | Geography & imperial cone snail Cone snail Conidae is a taxonomic family of minute to quite large sea snails, marine gastropod molluscs in the superfamily Conoidea.The snails within this family are sophisticated predatory animals... , pond snail, sea hare Sea hare The clade Aplysiomorpha, commonly known as Sea hares or Sea Bags , are medium-sized to very large Opisthobranchia with a soft internal shell made of protein... , leech Leech Leeches are segmented worms that belong to the phylum Annelida and comprise the subclass Hirudinea. Like other oligochaetes such as earthworms, leeches share a clitellum and are hermaphrodites. Nevertheless, they differ from other oligochaetes in significant ways... |
| Cys-Ile-Ile-Arg-Asn-Cys-Pro-Arg-Gly-NH2 | Arg-Connopressin | Striped cone snail |
| Cys-Tyr-Phe-Arg-Asn-Cys-Pro-Ile-Gly-NH2 | Cephalotocin | Octopus Octopus The octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms... |
| Cys-Phe-Trp-Thr-Ser-Cys-Pro-Ile-Gly-NH2 | Octopressin | Octopus |
| †Vasotocin is the evolutionary progenitor of all the vertebrate neurohypophysial hormones. | ||
Role in disease
Decreased vasopressin release or decreased renal sensitivity to AVP leads to diabetes insipidusDiabetes insipidus
Diabetes insipidus is a condition characterized by excessive thirst and excretion of large amounts of severely diluted urine, with reduction of fluid intake having no effect on the concentration of the urine. There are several different types of DI, each with a different cause...
, a condition featuring hypernatremia
Hypernatremia
Hypernatremia or hypernatraemia is an electrolyte disturbance that is defined by an elevated sodium level in the blood. Hypernatremia is generally not caused by an excess of sodium, but rather by a relative deficit of free water in the body...
(increased blood sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
concentration), polyuria
Polyuria
Polyuria is a condition usually defined as excessive or abnormally large production or passage of urine . Frequent urination is sometimes included by definition, but is nonetheless usually an accompanying symptom...
(excess urine production), and polydipsia
Polydipsia
Polydipsia is a medical symptom in which the patient displays excessive thirst. The word derives from the Greek πολυδιψία, which is derived from πολύς + δίψα...
(thirst).
High levels of AVP secretion (syndrome of inappropriate antidiuretic hormone
Syndrome of inappropriate antidiuretic hormone
The syndrome of inappropriate antidiuretic hormone hypersecretion is characterized by excessive release of antidiuretic hormone from the posterior pituitary gland or another source. The result is hyponatremia and sometimes fluid overload...
, SIADH) and resultant hyponatremia
Hyponatremia
Hyponatremia is an electrolyte disturbance in which the sodium concentration in the serum is lower than normal. In the vast majority of cases, hyponatremia occurs as a result of excess body water diluting the serum sodium and is not due to sodium deficiency. Sodium is the dominant extracellular...
(low blood sodium levels) occurs in brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
diseases and conditions of the lung
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
s (Small cell lung carcinoma). In the perioperative
Perioperative
The perioperative period, less commonly spelled the peroperative period, is the time period describing the duration of a patient's surgical procedure; this commonly includes ward admission, anesthesia, surgery, and recovery. Perioperative generally refers to the three phases of surgery:...
period, the effects of surgical stress and some commonly used medications (e.g., opiates, syntocinon, anti-emetics) lead to a similar state of excess vasopressin secretion. This may cause mild hyponatremia for several days.
Hyponatremia can be treated pharmaceutically through the use of vasopressin receptor antagonist
Vasopressin receptor antagonist
A vasopressin receptor antagonist is an agent which interferes with action at the vasopressin receptors. They can be used in the treatment of hyponatremia, especially in patients with congestive heart failure or liver cirrhosis.-Tetracyclines:...
s. These include the approved drug Vaprisol and the phase III drug lixivaptan
Lixivaptan
Lixivaptan is a phase III pharmaceutical being developed by Cardiokine, Inc., a specialty pharmaceutical company based in Philadelphia, PA, focused on the development of pharmaceuticals for the treatment and prevention of cardiovascular diseases...
.
Vasopressin analogues
Vasopressin agonists are used therapeutically in various conditions, and its long-acting synthetic analogue desmopressinDesmopressin
Desmopressin is a synthetic replacement for vasopressin, the hormone that reduces urine production. It may be taken nasally, intravenously, or as a tablet...
is used in conditions featuring low vasopressin secretion, as well as for control of bleeding (in some forms of von Willebrand disease
Von Willebrand disease
von Willebrand disease is the most common hereditary coagulation abnormality described in humans, although it can also be acquired as a result of other medical conditions. It arises from a qualitative or quantitative deficiency of von Willebrand factor , a multimeric protein that is required for...
and in mild haemophilia A
Haemophilia A
Haemophilia A is a deficiency in clotting factor VIII.Haemophilia A is inherited as an X-linked recessive trait, and thus occurs in males and in homozygous females. However, mild haemophilia A has been described in heterozygous females, presumably due to extremely unfavourable lyonization...
) and in extreme cases of bedwetting by children. Terlipressin
Terlipressin
Terlipressin is an analogue of vasopressin used as a vasoactive drug in the management of hypotension. It has been found to be effective when norepinephrine does not help.Indications for use include norepinephrine-resistant septic shock and hepatorenal syndrome...
and related analogues are used as vasoconstrictors in certain conditions. Use of vasopressin analogues for esophageal varices
Esophageal varices
In medicine , esophageal varices are extremely dilated sub-mucosal veins in the lower esophagus...
commenced in 1970.
Vasopressin infusion has been used as a second line of management in septic shock
Septic shock
Septic shock is a medical emergency caused by decreased tissue perfusion and oxygen delivery as a result of severe infection and sepsis, though the microbe may be systemic or localized to a particular site. It can cause multiple organ dysfunction syndrome and death...
patients not responding to high dose of inotrope
Inotrope
An inotrope is an agent that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular contractions...
s (e.g., dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
or norepinephrine
Norepinephrine
Norepinephrine is the US name for noradrenaline , a catecholamine with multiple roles including as a hormone and a neurotransmitter...
). It had been shown to be more effective than epinephrine in asystolic
Asystole
In medicine, asystole is a state of no cardiac electrical activity, hence no contractions of the myocardium and no cardiac output or blood flow...
cardiac arrest
Cardiac arrest
Cardiac arrest, is the cessation of normal circulation of the blood due to failure of the heart to contract effectively...
. While not all studies are in agreement, a 2006 study of out-of hospital cardiac arrests has added to the evidence for the superiority of AVP in this situation, but these studies relied on sub-group analysis and better designed prospective studies show no benefit in ACLS.
Vasopressin receptor inhibition
A vasopressin receptor antagonistVasopressin receptor antagonist
A vasopressin receptor antagonist is an agent which interferes with action at the vasopressin receptors. They can be used in the treatment of hyponatremia, especially in patients with congestive heart failure or liver cirrhosis.-Tetracyclines:...
is an agent that interferes with action at the vasopressin receptor
Vasopressin receptor
A vasopressin receptor is a cell surface receptor which binds vasopressin. The three types of vasopressin receptor are members of the A6 subfamily of G-protein coupled receptors.-Subtypes:Humans express three subtypes: 1A, 1B and 2-Function:...
s. They can be used in the treatment of hyponatremia
Hyponatremia
Hyponatremia is an electrolyte disturbance in which the sodium concentration in the serum is lower than normal. In the vast majority of cases, hyponatremia occurs as a result of excess body water diluting the serum sodium and is not due to sodium deficiency. Sodium is the dominant extracellular...
.
External links
- Molecular neurobiology of social bonding: Implications for autism spectrum disorders a lecture by Prof. Larry Young, Jan. 4, 2010.