EFFECTS OF BRADYKININ ON THE INTRACELLULAR CALCIUM-CONCENTRATION OF PANCREATIC ACINAR AR42J CELLS

We examined the effects of bradykinin (BK) on the intracellular free c alcium concentration ([Ca2+](i)) in rat pancreatic acinar AR42J cells. BK induced a dose-dependent rise in [Ca+2](i) in AR42J cells between the concentrations of 10(-12) M and 10(-7) M. The BK-evoked response w as not affected by the presence of Co2+ Or the absence of extracellula r calcium. This response was suppressed by neomycin or the B-2 antagon ist, but not by the B-1 antagonist. The response was also attenuated b y treatment with dexamethasone. These results suggest that BK increase s [Ca2+](i) through the B-2 receptors by promoting the phosphatidyl in ositol turn-over and that, in the process of azaserine-induced undiffe rentiation, the pancreatic acinar cells strongly express the BK recept ors.