Comparison of the histamine-releasing action of substance P on mast cells and basophils from different species and tissues.

The action of the neuropeptide substance P as a histamine-releasing agent has been compared in histamine-containing cells from a variety of different tissues and species. Peritoneal mast cells from rat, mouse and hamster but not human cells gave a concentration-dependent release of histamine in response to substance P. Release was greater in the absence than in the presence of calcium in the extracellular medium. Mast cells from rat mesentery, lung and heart released histamine in response to substance P, but heart mast cells responded only weakly. All guinea-pig mast cells and histamine-containing cells from human tissues did not give any substantial substance-P-induced release of histamine. The data provides further evidence for the functional heterogeneity of histamine-containing cells.