Enteropooling assay: a test for diarrhea produced by prostaglandins

Area of Science:

• Pharmacology
• Gastroenterology
• Physiology

Background:

• Prostaglandins are known to cause diarrhea.
• The exact mechanism of prostaglandin-induced diarrhea, particularly the role of fluid accumulation versus hypermotility, requires further elucidation.

Purpose of the Study:

• To describe a novel enteropooling assay for quantifying the diarrheogenic properties of prostaglandins.
• To investigate the mechanism of prostaglandin-induced diarrhea.

Main Methods:

• An enteropooling assay was developed using fasted rats.
• Rats were administered prostaglandins orally or subcutaneously and euthanized after 30 minutes.
• Intestinal fluid volume was measured to assess diarrheogenic activity.

Main Results:

• The enteropooling assay demonstrated a quantitative correlation between prostaglandin dose and intestinal fluid volume.
• High doses of prostaglandins led to significant fluid accumulation in the small intestine, supporting the enteropooling hypothesis.
• Other agents like castor oil, hypertonic solutions, and bile salts also induced enteropooling.

Conclusions:

• The enteropooling assay is a simple, rapid, and predictive tool for evaluating diarrheogenic potential.
• Diarrhea induced by high-dose prostaglandins is primarily due to fluid accumulation in the small intestine, not hypermotility.
• The assay can be used to screen agents that may inhibit prostaglandin-induced diarrhea.