Define ADH and describe the mechanism of its action

ADH stands for anti-diuretic hormone. It is a hormone that increases the permeability of the distal convoluted tubule and the collecting duct to water ADH is produced in the hypothalamus and stored in the pituitary gland where it is also released.MechanismADH is released from the pituitary gland and carried in the blood to the cells of the collecting duct where it has its effect. The hormone binds to receptors on the cell membrane and triggers the formation of cAMP - a second messenger inside the cell. Vesicles in the cell fuse with cell surface membrane. The membranes of these vesicles contain aquaporins which are water channels. When they are inserted into the cell surface membrane they make it permeable to water. Water then passes out of the tubule cells into the blood by osmosis.