Effect of zaldaride maleate, an antidiarrheal compound, on 16,16-dimethyl prostaglandin E-2-induced intestinal ion secretion in rats

The effect of zaldaride, a calmodulin inhibitor, on 16,16-dimethyl prostagl andin E-2 (dmPGE(2))induced intestinal ion secretion was investigated in ra ts. Zaldaride inhibited the dmPGE(2)-induced increase in water content in t he colon, but not that in the small intestine. In the colonic mucosa, zalda ride attenuated the dmPGE(2)-induced short-circuit current; however, it did not affect the forskolin or dibutyryl cAMP-induced effect. These results s uggest that zaldaride inhibits dmPGE(2)-induced intestinal ion secretion by reducing the activity of Ca2+/calmodulin-dependent adenylate cyclase linke d to a receptor, and the colon may be an important site in the action of za ldaride.