arginine vasopressin

Mammal hypothalamus supraoptic and paraventricular nuclei synthesize octapeptides or nonapeptides {arginine vasopressin}| (AVP).

functions

AVP regulates water balance. Decreased blood volume or increased plasma osmotic pressure causes AVP secretion. AVP causes blood-vessel constriction, maintaining blood pressure in cases of decreased blood volume. AVP stimulates intestinal motility, lowering fluid loss. AVP increases cell permeability to water in kidney collecting tubules. AVP enhances sodium-chloride active transport in renal medullary tubules.

AVP secretes in pain and stress. AVP stimulates adrenocorticotropic hormone release, triggering adrenal steroid secretions and stress responses.

AVP can affect mammal pair bonding and infant care.

receptors

AVP binds to kidney-tubule, vascular smooth-muscle, pituitary, and intestinal cell receptors.

receptors: baroreceptor

Reduced blood volume decreases blood pressure and stimulates low-pressure stretch baroreceptors in left atrium, aorta, and carotid. Baroreceptors stimulate glossopharyngeal and vagus nerves to hypothalamus, which liberates AVP from pituitary nerve terminals.

receptors: osmoreceptor

Increased plasma concentration and higher osmolality stimulate osmoreceptors in hypothalamus, resulting in AVP secretion.

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Date Modified: 2022.0224