Spontaneously hypertensive rat
Encyclopedia
Spontaneously hypertensive rat (SHR) is an animal model of essential (or primary) hypertension
, used to study cardiovascular disease
. It is the most studied model of hypertension measured as number of publications . The SHR strain
was obtained during the 1960s by Okamoto and colleagues, who started breeding
Wistar-Kyoto rats with high blood pressure
.
pressures between 180 and 200 mmHg
in the adult age phase. Starting between 40 and 50 weeks, SHR develops characteristics of cardiovascular disease, such as vascular
and cardiac
hypertrophy .
a kidney from SHR to a normotensive Wistar rat increases blood pressure in the recipient. Conversely, transferring a Wistar kidney to SHR normalizes blood pressure in the recipient . This also happens if transplantation takes place at young age before established hypertension in the donors , indicating a primary role for the kidney in the development of hypertension in SHR.
model, the strain exhibit interesting compensatory abilities. For example, kidneys transplanted from SHR to a hypertensive recipient retain better morphology
than kidneys transplanted from Brown Norway
, demonstrating an apithological http://www.emrgnc.com.au/apithology.htm adaptation to high blood pressure.
. If the animal is to be used as a model of ADHD, it is generally advised to start testing when the animals are around four weeks old (PND 28) before the onset of hypertension.
Despite the criticisms associated with using animals to research essentially human conditions, Sagvolden supported his Dynamic Developmental Theory of ADHD using research primarily done using Spontaneously Hypertensive Rats.
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
, used to study cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
. It is the most studied model of hypertension measured as number of publications . The SHR strain
Strain (biology)
In biology, a strain is a low-level taxonomic rank used in three related ways.-Microbiology and virology:A strain is a genetic variant or subtype of a micro-organism . For example, a "flu strain" is a certain biological form of the influenza or "flu" virus...
was obtained during the 1960s by Okamoto and colleagues, who started breeding
Animal husbandry
Animal husbandry is the agricultural practice of breeding and raising livestock.- History :Animal husbandry has been practiced for thousands of years, since the first domestication of animals....
Wistar-Kyoto rats with high 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...
.
Pathophysiology
Hypertensive development begins around 5–6 weeks of age, reaching systolicSystole (medicine)
Systole is the contraction of the heart. Used alone, it usually means the contraction of the left ventricle.In all mammals, the heart has 4 chambers. The left and right ventricles pump together. The atria and ventricles pump in sequence...
pressures between 180 and 200 mmHg
Torr
The torr is a non-SI unit of pressure with the ratio of 760 to 1 standard atmosphere, chosen to be roughly equal to the fluid pressure exerted by a millimetre of mercury, i.e., a pressure of 1 torr is approximately equal to 1 mmHg...
in the adult age phase. Starting between 40 and 50 weeks, SHR develops characteristics of cardiovascular disease, such as vascular
Circulatory system
The circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, etc...
and cardiac
Ventricular hypertrophy
Ventricular hypertrophy is the enlargement of ventricles in the heart. Although left ventricular hypertrophy is more common, enlargement can also occur in the right ventricle, or both ventricles.- Physiology :...
hypertrophy .
Blood pressure in SHR depends on the kidney
Hypertensive development is somehow connected to the kidney. TransplantingKidney transplantation
Kidney transplantation or renal transplantation is the organ transplant of a kidney into a patient with end-stage renal disease. Kidney transplantation is typically classified as deceased-donor or living-donor transplantation depending on the source of the donor organ...
a kidney from SHR to a normotensive Wistar rat increases blood pressure in the recipient. Conversely, transferring a Wistar kidney to SHR normalizes blood pressure in the recipient . This also happens if transplantation takes place at young age before established hypertension in the donors , indicating a primary role for the kidney in the development of hypertension in SHR.
SHR and coping
Even though SHR is usually considered to be a purely pathologicalPathology
Pathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek , pathos, "feeling, suffering"; and , -logia, "the study of". Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling....
model, the strain exhibit interesting compensatory abilities. For example, kidneys transplanted from SHR to a hypertensive recipient retain better morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
than kidneys transplanted from Brown Norway
Brown Rat
The brown rat, common rat, sewer rat, Hanover rat, Norway rat, Brown Norway rat, Norwegian rat, or wharf rat is one of the best known and most common rats....
, demonstrating an apithological http://www.emrgnc.com.au/apithology.htm adaptation to high blood pressure.
The stroke prone SHR
Stroke prone SHR (SHR-SP) is a further development of SHR that has even higher blood pressure than SHR and a strong tendency to die from stroke.Attention Deficit Hyperactivity Disorder
The Spontaneously Hypertensive Rat (SHR) is also used as a model of attention-deficit hyperactivity disorderAttention-deficit hyperactivity disorder
Attention deficit hyperactivity disorder is a developmental disorder. It is primarily characterized by "the co-existence of attentional problems and hyperactivity, with each behavior occurring infrequently alone" and symptoms starting before seven years of age.ADHD is the most commonly studied and...
. If the animal is to be used as a model of ADHD, it is generally advised to start testing when the animals are around four weeks old (PND 28) before the onset of hypertension.
Despite the criticisms associated with using animals to research essentially human conditions, Sagvolden supported his Dynamic Developmental Theory of ADHD using research primarily done using Spontaneously Hypertensive Rats.