Histamine release and local responses of rat and human skin to substance P and other mammalian tachykinins.

Substance P and two recently identified neurokinins, substance K and neuromedin K as well as the nonmammalian tachykinin kassinin were compared for histamine-releasing abilities from rat mast cells, plasma extravasation effects on rat skin, and wheal and flare responses on human skin. Among the four tachykinins, a significantly dose-dependent histamine release from rat mast cells and a flare response in human skin was observed only with substance P, indicating the possible implication of histamine in this response. On the other hand, the four peptides were similarly active on the wheal response (plasma extravasation produced by increased permeability of capillaries and venules) in human skin and on the plasma extravasation in the rat skin, suggesting a dissociation of effects and possibly of receptors.