Release of Histamine from Mast Cells by Vasoactive Peptides

The effect of a variety of synthetic peptides on rat mast cells was investigated. Peptides with two or more basic groups were active histamine releasers, while eledoisin, angiotensin I and II, glucagon, and fibrinOpeptide A had slight or no activity. The activity of bradykinin analogues increased with the chain length. Des-arginine derivatives of bradykinin did not release histamine. The most potent histamine liberators were substance P and Polistes kinin; the activity of the latter one approached that of 48/80. Because histamine could be released by the kinin peptides without disruption of the mast cell membrane, these agents like 48/80, probably stimulate exocytosis of mast cell granules.