The discovery of hypothalamic factors that inhibited growth hormone secretion and of pancreatic factors that inhibited insulin secretion were the first clues to the existence of somatostatin. During the course of efforts to isolate growth hormone releasing factor, Krulich, McCann and Dhariwal found that hypothalamic extracts contained a potent inhibitor of growth hormone secretion. They postulated that growth hormone secretion was under a dual control system, one inhibitory and the other excitatory (I) . In studies being carried out at about the same time, Hellman and Lernmark found a factor...

The elucidation of the structure, function, and clinical significance of the neurohypophysis has been one of the most rewarding chapters in the history of endocrinology. Diabetes insipidus, which can be manifested by passage of 15 liters of urine a day, is one of the most dramatic disorders of the endocrine system, and can readily be managed by replacement therapy with the natural secretions of this gland, or with synthetic analogues that provide a more favorable therapeutic ratio. The neurohypophysis is the archetypical neurosecretory gland. Its secretions arise within well defined nerve...