Vasopressin receptor 1A

Vasopressin Receptor 1A' (V1AR), also known as the arginine vasopressin receptor 1A, is a protein that in humans is encoded by the AVPR1A gene. It is a type of receptor for arginine vasopressin, a small peptide hormone that regulates the body's retention of water. The V1AR is a G protein-coupled receptor (GPCR) that plays a critical role in the regulation of vasoconstriction, blood pressure, and kidney function.

Function

The V1A receptor is primarily found in the vascular smooth muscle and myocardium, where it mediates the contraction of smooth muscle cells, leading to an increase in blood pressure. It is also present in the brain, where it is involved in a variety of central nervous system functions, including social behavior, pair bonding, and stress response. Activation of the V1A receptor by arginine vasopressin leads to a series of intracellular events involving the activation of phospholipase C and the increase in intracellular calcium levels.

Clinical Significance

Alterations in V1A receptor function have been implicated in several diseases, including heart failure, chronic kidney disease, and psychiatric disorders such as autism spectrum disorder and depression. Drugs that act as antagonists to the V1A receptor, known as vaptans, are being explored for the treatment of conditions like hyponatremia and heart failure, by blocking the effects of arginine vasopressin and thus promoting water excretion without loss of electrolytes.

Genetics

The AVPR1A gene is located on the short arm of chromosome 12 (12q14-15) and consists of three exons and two introns. Genetic variations in AVPR1A have been studied in relation to social behavior, with some alleles being associated with increased social communication and others with more solitary behaviors. This has led to the hypothesis that the V1A receptor may play a role in the evolutionary basis of social behaviors in humans and other mammals.

Pharmacology

Pharmacologically, the V1A receptor is a target for the development of drugs that can modulate vasopressin's effects in the body. Antagonists of the V1A receptor, such as conivaptan and tolvaptan, are used clinically to treat diseases related to water retention and heart failure. These drugs work by blocking the action of vasopressin at the V1A receptor, thereby promoting the excretion of free water and correcting hyponatremia.

See Also

• Vasopressin receptor
• Vasopressin
• G protein-coupled receptor
• Hyponatremia
• Heart failure