Antidiuretic hormones
What are Antidiuretic hormones?
Antidiuretic hormone, also known as vasopressin is a hormone released by the posterior pituitary. It is important mainly for its actions on the kidneys where it increases the re-absorption of water. Vasopressin is also a powerful vasoconstrictor. Its effects are through two types of receptors, V1 and V2.
Water retention is mediated through V2 receptors, occurs at low plasma concentrations of vasopressin and is due to activation of adenylate cyclase and increased cAMP production in the collecting ducts of the nephrons. It increases the permeability of the membrane to water.
Vasopressin causes contraction of smooth muscle, mainly in the cardiovascular system. Vasocontriction occurs by mediation of V1 receptors and requires higher concentrations if vasopressin.
A hormone that helps blood vessels constrict and helps the kidneys control the amount of water and salt in the body. This helps control blood pressure and the amount of urine that is made.
Antidiuretic hormone (ADH) is a chemical produced in the brain that causes the kidneys to release less water, decreasing the amount of urine produced. A high ADH level causes the body to produce less urine. A low level results in greater urine production.





