Effect of zaldaride maleate, an antidiarrheal compound, on fecal pellet output induced by hyperpropulsion in gastrointestine of rats.

The effect of zaldaride, a calmodulin inhibitor, on fecal pellet output in rats was compared with that of loperamide, an antidiarrheal drug. 5-Hydroxytryptamine (10 mg/kg, s.c.), neostigmine (0.3 mg/kg, s.c.) and nicotine (1.0 mg/kg, s.c.) increased fecal pellet output. Zaldaride (> or = 30 mg/kg, p.o.) reduced these increases in fecal pellet outputs. Loperamide (10 mg/kg, p.o.) inhibited fecal pellet output induced by 5-hydroxytryptamine and neostigmine but not nicotine. Under normal conditions, zaldaride and loperamide did not affect fecal pellet output at doses used in these studies. In conclusion, zaldaride may inhibit increases in fecal pellet output induced by hyperpropulsion of the gastrointestinal tract without causing constipation as a side effect.