Stimulation of Salivary Secretion by a Factor Extracted from Hypothalamic Tissue¹

A polypeptide that stimulates an increase in the volume and α-amylase activity of saliva within seconds after intravenous injection into anesthetized rats has been detected and partially purified from bovine and rat hypothalamic tissue. This polypeptide, first noticed after fractionation of bovine hypothalamic extracts on G-75 Sephadex and named sialogen, gives a dose-response curve for volume and α amylase activity of the collected saliva, retainsits activity in test rats pretreated with atropine sulfate, phenoxybenzamine, or propranolol, and is still active in hypophysectomized rats. Purification by cation exchange chromatography on sulfoethyl Sephadex C-25 shows that bovine sialogen is a strongly basic substance. If sialogen proves to be of physiological significance it may function as a neurohormone participating with the nervous system in the regulation of salivary secretion. (Endocrinology81: 803,1967)