Protective effect of disodium cromoglycate on rat peritoneal mast cells.

Disruption of mast cells was measured by incubating the peritoneal washings of a rat with the substances under test. The incubate was filtered and the histamine in the undisrupted mast cells on the filter was assayed using guinea-pig ileum. Measurements were also made on disruption of rat peritoneal mast cells in vivo. Disodium cromoglycate (DCG) reduces the in vitro disruption of peritoneal mast cells produced by Compound 48/80, human plasma, dextran, and trypsin inhibitors. Compound 48/80 produced its greatest mast cell disruption at a calcium concentration of 0-2-2 mM CaCl2. DCG was effective in reducing the mast cell disruption at all calcium concentrations. Mast cell disruption by surface active agents was also reduced by DCG. In vivo experiments showed that DCG reduced the disruptive effect of Compound 48/80 on rat mesenteric mast cells. Calculations based on bronchial morphology show that the concentrations of DCG used in these experiments may be attained therapeutically in the bronchial mucosa of man.