EFFECT OF 5-HT3 ANTAGONIST ONDANSETRON ON WRAP-RESTRAINT AND CONDITIONED EMOTIONAL STRESS INDUCED DEFECATION

The effect of ondansetron was investigated in wrap-restraint and conditioned emotional (footshock) stress induced colonic hypermotility in rat. Ondansetron was administered in doses of 0.1, 0.5 and 1 mg/kg, sc. In wrap-restraint group, ondansetron dose-dependently reduced the fecal output to baseline levels (0.51 ± 0.20 gm/rat, 0.48 ± 0.38 gm/rat, 0.38 ± 0.16 gm/rat with 0.1, 0.5 and 1 mg/kg respectively). Diazepam, 5 mg/kg and atropine, 1 mg/kg also decreased the fecal output in this model. In footshock group, ordansetron did not affect the emotional stress induced increase in fecal pellet output. Diazepam and atropine however, decreased the fecal output in this model also.