Abstract
45Ca uptake by rat peritoneal mast cells was observed, and the inhibitory effect of nifedipine, a Ca2+ antagonist, on 45Ca uptake by mast cells, stimulated by an antigen, comp. 48/80, concanavalin A and Ca ionophore A 23187, was examined. The increase in 45Ca uptake by mast cells induced by the antigen paralleled the increase in mast cell number. A significant increase in the uptake of 45Ca by mast cells was observed with the stimulation by the antigen, comp. 48/80, concanavalin A and Ca ionophore A 23187. The increased uptake of 45Ca induced by antigen was inhibited by nifedipine, and this dose-dependent inhibitory effect of nifedipine on 45Ca uptake was also observed in the mast cells stimulated by comp. 48/80, concanavalin A and Ca ionophore A 23187.
