Mechanism of Release and Mechanism of Action of Vasopressin

Abstract

Vasopressin and oxytocin or one or several precursors of them are produced in the pericarya of cells in certain nuclei of the hypothalamus and maybe also within the axons leading from these cell bodies to the neural lobe of the pituitary. The hormones or their precursors are transported in neurosecretory granules from the perikarya of the cells to the neural lobe where they are stored and from where the controlled release takes place. The appropriate (or inappropriate) stimuli for release produce nerve signals, the last pathway of which is the nerve membrane surrounding the terminal swellings of the axon. There is no information on the speed with which the neurosecretory granules move within the axons.