Effects of beta-endorphin on rat mast cells

The endogenous opioid peptide beta-endorphin induced a dose-dependent release of histamine from rat peritoneal mast cells. The threshold concentration was around 10(-6) M and the optimal concentration of 2 X 10(-5) M released 35% of the total histamine. The release of histamine was very rapid, complete within 10 s, and very similar to that induced by neurotensin or compound 40/80. The histamine release was temperature dependent and inhibited at increased extracellular calcium concentrations. Taken together, the findings indicate that the release of histamine induced by beta-endorphin is a specific, energy-dependent process. The pattern of release has much in common with that induced by other basic peptides, such as neurotensin, dynorphin and substance P.