Kassinin: stimulation of insulin and glucagon secretion in the rat

The effect of the newly discovered tachykinin dodecapeptide kassinin on endocrine pancreatic function was examined in the rat and compared to that of substance P, a neuropeptide which is structurally closely related to kassinin. Kassinin, injected iv in graded doses 10, 20, and 30 min before blood collection, significantly increased both plasma insulin and plasma glucagon in a dose-related fashion. The largest dose examined (10 micrograms) increased plasma insulin by 275% and plasma glucagon by 77%. In contrast, iv injections of equimolar doses of substance P did not affect either hormone. However, both kassinin and substance P increased plasma glucose levels in a dose-dependent fashion. Kassinin appears to have biological actions on the endocrine pancreas which clearly can be distinguished from those of substance P. Should kassinin be present in mammalian tissue and show a distribution similar to that of other neuropeptides, it may play a role in the physiological regulation of carbohydrate metabolism.