Immunologically induced histamine release from rat peritoneal mast cells is enhanced by low levels of substance P

Although direct activation of mast cells by high concentrations (>10−6 M) of substance P is well established, the effect of sub-micromolar concentrations of the neuropeptide on mast cell activation has not been reported. We hence investigated if substance P would modulate immunologic activation of mast cells by studying the effect of the neuropeptide on anti-rat immunologlobulin E antibody (anti-IgE)-induced histamine release from purified rat...