Enigma of disodium cromoglycate action on mast cells

In rat peritoneal mast cells, disodium cromoglycate showed no inhibitory effect on histamine release values if the cells were preincubated with the drug for 40 min prior to stimulation with antigen, compound 48/80 or ATP. If the drug was added simultaneously with antigen or a low dose of compound 48/80, a repression of histamine release occurred. No such effect was noted if ATP was employed as histamine liberator.