Effect of cyclic AMP, disodium cromoglycate and other anti-allergic drugs on histamine secretion from rat mast cells stimulated with the calcium ionophore ionomycin.

Cyclic AMP analogues and the anti-allergic drugs disodium cromoglycate, quercetin, doxantrazole and theophylline inhibited histamine secretion from rat peritoneal mast cells stimulated with the calcium ionophore ionomycin. The potency of the compounds varied inversely with the concentration of ionophore and with the period of incubation. The drugs were active in both the presence and absence of extracellular calcium. These results cannot be explained in terms of the postulated effect of the compounds on the receptor-mediated activation of calcium-channels. Alternative mechanisms for their action are thus considered.