Vasopressin: Difference between revisions
Vasopressin (ADH) is released from the posterior pituitary gland to increase blood pressure by increasing water absorption in the collecting duct |
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Revision as of 17:47, 9 November 2010
Vasopressin also known as ADH (Anti Diuretic Hormone) is a hormone causing an increase in blood pressure.
Osmoreceptors in the hypothalamus stimulates the posterior pituitary gland to release vasopressin (ADH) into the bloodstream when blood osmolarity is high and blood pressure is low due to a low water volume in the blood.
Via the bloodstream vasopressin is transferred to its target receptor located in the basolateral membrane of the epithelia in the renal collecting duct. Vasopressin binding stimulates the insertion of Aquaporin 2 (AQP2) water channels into the apical membrane of epithelia resulting in water now being absorbed into the blood stream. The blood pressure increases as the water volume in the blood rises.
The rise in water volume reduces the osmolarity of the blood and thereby provides negative feedback to the osmoreceptors, preventing that too much water will be absorbed.
Related subjects: Renin-Angiotensin_System,