Cellular and molecular events in the action of antidiuretic hormone.

The urinary concentrating mechanism and the action of antidiuretic hormone (ADH) were subjects of great controversy in the 1950's. Since then, steady progress has been made in our understanding of the cellular action of ADH. We have a good picture of the cyclic process by which vesicles carrying water channels move from cytoplasm to apical membrane, deposit water channels, and are then recovered by endocyosis. There is progress towards a complete description of the structure of the channels themselves. As well, in secretory cells such as the nerve terminal and the chromaffin cell, there are principles of cytoskeletal control and vesicle docking that appear to apply to the nephron.