Effect of anti-allergic compounds on histamine release from rat peritoneal mast cells treated with concanavalin A.

The anti-allergic drugs theophylline, doxantrazole, quercetin, dibutyryl cyclic AMP, and disodium cromoglycate prevented histamine release induced by concanavalin A in both the presence and absence of extracellular calcium. The compounds were generally most effective in the absence of added calcium and least effective in the simultaneous presence of calcium and phosphatidyl serine. The activity of the test drugs in calcium-free media clearly cannot be explained in terms of their postulated ability to block movement of the ion from the external environment into the cell. Alternative modes of action are thus considered.