ADH(antidiuretic hormone) effect on kidney function

Antidiuretic hormone(vasopressin) released by the posterior lobe of the pituitary plays a role in water reabsorption by the distal convoluted tubule and the collecting duct of the nephron.

ADH increase the water reabsorption. In practical term, if an individual does not drink much water on a certain day, the posterior lobe of the pituitary releases ADH, causing more water to be reabsorbed and less urine to form (antidiuresis).

On the other hand, if an individual drinks a large amount of water and does not prespire much, ADH is not released. In that case, more water is excreted and more urine forms( diuresis)

In this figure, ADH regulates the permeability of the late distal tubules and collecting ducts. ADH stimulates the synthesis of aquaporin- 2 and it's insertion into the membranes of the principal cells. ADH acts by binding to GPCR receptor on the plasma membrane. These receptor activate the enzyme adenylate cyclase through G protein which catalyses the synthesis of cAMP.

cAMP stimulates synthesis of aquaporin- 2 and insertion into the apical membrane by exocytosis.

NOTE= A deficiency in ADH secretion causes diabetes insipidus in which there is excessive urination ( polyuria) and excessive fluid intake( polydypsia)

Thanks, 

Shubham Sharma

Gmail- sspareek1998@gmail.com