Morphine-3-glucuronide is a metabolite of morphine

Morphine

Morphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...

 produced by UGT2B7

UGT2B7

UGT2B7 is a phase II metabolism isoenzyme found to be active in the liver, kidneys, epithelial cells of the lower gastrointestinal tract and also has been reported in the brain...

. It is not active as an opioid

Opioid receptor

Opioid receptors are a group of G protein-coupled receptors with opioids as ligands. The endogenous opioids are dynorphins, enkephalins, endorphins, endomorphins and nociceptin. The opioid receptors are ~40% identical to somatostatin receptors...

 agonist

Agonist

An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...

, but does have some action as a convulsant

Convulsant

A convulsant is a drug which induces convulsions and/or epileptic seizures, the opposite of an anticonvulsant. These drugs generally act as stimulants at low doses, but are not used for this purpose due to the risk of convulsions and consequent excitotoxicity...

, which does not appear to be mediated through opioid receptors; it is mediated by GABA/glycinergic system. As a polar compound, it has a limited ability to cross the blood-brain barrier

Blood-brain barrier

The blood–brain barrier is a separation of circulating blood and the brain extracellular fluid in the central nervous system . It occurs along all capillaries and consists of tight junctions around the capillaries that do not exist in normal circulation. Endothelial cells restrict the diffusion...

, but renal failure may lead to its accumulation and result in seizures. Probenecid

Probenecid

Probenecid is a uricosuric drug that increases uric acid excretion in the urine. It is primarily used in treating gout and hyperuricemia.Probenecid was developed as an alternative to caronamide...

 and inhibitors of P-glycoprotein can enhance uptake of morphine-3-glucuronide and, to a lesser extent, morphine-6-glucuronide

Morphine-6-glucuronide

Morphine-6-glucuronide is a major active metabolite of morphine, and as such is the molecule responsible for much of the pain-relieving effects of morphine . M6G is formed from morphine by the enzyme UDP-Glucuronosyltransferase-2B7...

.

See also

• Glucuronide
  Glucuronide
  A glucuronide, also known as glucuronoside, is any substance produced by linking glucuronic acid to another substance via a glycosidic bond...
  
  
• Morphine-6-glucuronide
  Morphine-6-glucuronide
  Morphine-6-glucuronide is a major active metabolite of morphine, and as such is the molecule responsible for much of the pain-relieving effects of morphine . M6G is formed from morphine by the enzyme UDP-Glucuronosyltransferase-2B7...
  
  
• 3-monoacetylmorphine
  3-Monoacetylmorphine
  3-Monoacetylmorphine or 3-acetylmorphine is less active metabolite of heroin , the other two being morphine and more active 6-monoacetylmorphine ....
  
  , the inactive 3,- position blocked by esterization (and thus inactive) of a semi-synthetic prodrug to morphine marking the same activity profile as drug of this article
• Morphine-N-oxide
  Morphine-N-oxide
  Morphine-N-oxide is an active opioid metabolite of morphine. Morphine itself, in trials with rats, acts 11–22 times more potent than morphine-N-oxide subcutaneously and 39–89 times more potent intraperitoneally...