Vasopressin, also known as antidiuretic hormone, is mainly released in large amounts after reaching the neurohypophysis through the hypothalamic-pituitary tract. The use of vasopressin can promote water absorption and plays an important role in the concentration and dilution of urine. Vasopressin can also enhance the permeability of urea, enabling the human body to maintain normal urination, reduce the occurrence of various urinary system diseases, and maintain a healthy body at all times.
What secretes vasopressin? Vasopressin is secreted by nerve cells innervated by the supraoptic nucleus and paraventricular nucleus of the hypothalamus. Its main function is to promote water absorption by the distal convoluted tubules and collecting ducts, increase permeability, and effectively enhance the absorption of urea by the inner medullary collecting ducts. Vascular smooth muscle and visceral smooth muscle can also be stimulated, stimulating the release of adrenocorticotropic hormone releasing factor, which can increase blood pressure, promote the release of ACTH, inhibit fatty acid formation, and enhance memory. If vasopressin secretion is insufficient, it will lead to increased urine output and even diabetes insipidus. If such symptoms occur, medical treatment should be sought promptly.
Physiological effects of vasopressin: ① Antidiuresis: ADH binds to specific receptors in the renal distal convoluted tubules and collecting ducts to form a hormone-receptor complex, activating adenylate cyclase, converting ATP to cAMP. Under the action of cAMP, protein kinase is activated, membrane protein phosphorylation increases, and the permeability of water by renal tubular epithelial cells increases, allowing water to be passively reabsorbed along the osmotic gradient. ② Elevated blood pressure: ADH causes vasoconstriction and visceral smooth muscle contraction, producing a pressor effect. Artificial ADH can be used in the treatment of esophageal varices rupture and bleeding. ③ Excitatory ACTH release: ADH can promote the secretion of ACTH secretagogues (CRF)-like substances, possibly by direct action of ACTH on the anterior pituitary gland, stimulating ACTH release, but not CRF. ④ Enhanced memory in animals. It decomposes glycogen and inhibits fatty acid synthesis in rats.
