Indomethacin-induced lesion modifies contractile activity in rat small intestines.

BACKGROUND

Indomethacin induces intestinal lesions. The change in contractility of segments with lesions was studied.

METHODS

Motility was recorded in segments with lesions isolated from the rat small intestine 24 h after a subcutaneous injection of indomethacin (20 mg/kg).

RESULTS

Concentration-contraction curves for acetylcholine shifted leftward independently of the degree of severity of lesions, but the curves for carbachol and 5-hydroxytryptamine did not. Contractions produced by intramural nerve stimulation were enhanced in segments with no visible damage but decreased with progression of lesions. Neostigmine augmented them in normal rats but not in indomethacin-treated rats. The peristaltic activity was enhanced in segments with no visible lesions.

CONCLUSIONS

The results suggest that treatment of the rat with indomethacin enhances contractility of the small intestine owing to diminution of acetylcholinesterase activity independently of the degree of lesions and reduces it owing to decreased responsiveness of enteric neurons with the progression of lesions.