Vasopressin: Difference between revisions
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[[Osmoreceptors|Osmoreceptors]] in the [[Hypothalamus|hypothalamus]] stimulates the posterior [[Pituitary gland|pituitary gland]] to release vasopressin (ADH) into the bloodstream when <u>blood osmolarity is high</u> and <u>blood pressure is low</u> due to a low water volume in the [[Blood|blood]]. | [[Osmoreceptors|Osmoreceptors]] in the [[Hypothalamus|hypothalamus]] stimulates the posterior [[Pituitary gland|pituitary gland]] to release vasopressin (ADH) into the bloodstream when <u>blood osmolarity is high</u> and <u>blood pressure is low</u> due to a low water volume in the [[Blood|blood]]. | ||
Via the bloodstream vasopressin is transferred to its target receptor located in the basolateral membrane of the [[Epithelia|epithelia]] in the renal collecting duct. | Via the bloodstream vasopressin is transferred to its target receptor located in the basolateral membrane of the [[Epithelia|epithelia]] in the renal collecting duct. The vasopressin binds to V2 receptors. This stimulates the insertion of [[Aquaporin 2|Aquaporin 2]] ([[Aquaporin 2|AQP2]]) water channels into the [[Apical membrane|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.This mechanism is used by the body to prevent hypotension. | ||
The rise in water volume reduces the [[Osmolarity|osmolarity]] of the blood and thereby provides [[Negative feedback|negative feedback]] to the [[Osmoreceptors|osmoreceptors]], preventing that too much water will be absorbed.<br> | The rise in water volume reduces the [[Osmolarity|osmolarity]] of the blood and thereby provides [[Negative feedback|negative feedback]] to the [[Osmoreceptors|osmoreceptors]], preventing that too much water will be absorbed.<br> | ||
Revision as of 20:24, 22 October 2012
Vasopressin also known as ADH (Anti Diuretic Hormone)[1] 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. The vasopressin binds to V2 receptors. This 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.This mechanism is used by the body to prevent hypotension.
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,