The cellular action of antidiuretic hormone

This chapter describes the techniques that have been used on vasopressin action, and to describe briefly the information that has been gained by this multifaceted approach to a cell biological problem. Binding of the antidiuretic hormone, vasopressin, to receptors on the basolateral plasma membrane of kidney collecting duct principal cells stimulates a cascade of events that results in a rapid and dramatic increase in the water permeability of the apical plasma membrane of these cells. The combination of morphology and biophysics has proved especially valuable for the investigation of water channel recycling at the apical membrane, while target analysis has provided novel information about initial steps in the vasopressin-induced stimulation of adenylate cyclase at the basolateral plasma membrane of vasopressin-sensitive epithelial cells. In particular, the identification and molecular cloning of the vasopressin-sensitive water channel is an active area of research in different laboratories. This is likely to be a difficult endeavor due in part to the lack of a highly specific inhibitor of bulk water flow across membranes.