Loperamide antagonism of castor oil-induced diarrhea in rats: a quantitative study.
The time-course of castor oil-induced diarrhea in fasted rats was quantified by weighing stools every 15 minutes for 8 hours after the challenge and then after 24 hours. Diarrhea began within 1 hour as a series of rapidly occurring evacuations over 20 to 40 minutes. The mean weight of these stools was 5.7 g; later irregular evacuations increased the weight to 9.4 g at 8 hours. The area of individual time-weight diagrams had a median value of 432 units. Pretreatment with 0.16 mg/kg of loperamide, a new antidiarrheal drug, significantly decreased the area of similarly obtained diagrams; 0.31 mg/kg caused a 50% reduction. This antagonism by loperamide of castor oil-induced diarrhea may involve reduction in the severity of inflammatory changes in the intestinal wall.
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002368:Castor Oil / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D003967:Diarrhea / Q000139:chemically induced* / Q000188:drug therapy; D005243:Feces; D005260:Female; D008139:Loperamide / Q000494:pharmacology* / Q000627:therapeutic use; D010880:Piperidines / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors
D010880:Piperidines; D008139:Loperamide; D002368:Castor Oil