Substance P-induced histamine release from human basophils, skin and lung fragments: effect of nedocromil sodium and theophylline.

We compared histamine release induced by substance P with those obtained with classical secretagogues on human basophils, lung and skin fragments. We also tested the capacity of nedocromil sodium and theophylline to inhibit histamine release in these 3 experimental models. Substance P (10(-4) M) caused a noncytotoxic histamine release (about 10% of total) from basophils, lung and skin fragments. Substance P-induced histamine release was always smaller than that obtained with optimal doses of anti-IgE, formyl-methionine phenylalanine or compound 48/80. Nedocromil sodium did not prevent secretagogue-induced histamine release from basophils or sliced skin. In contrast, it significantly inhibited anti-IgE- or substance P-induced histamine release from human lung. Theophylline caused a dose-related inhibition on these 3 models. We conclude that substance P is a modest secretagogue for human basophils and mast cells, and that skin and lung mast cells are heterogeneous with respect to their response to nedocromil sodium.