Effects of Prokinetic Agents on Motility of Proximal and Distal Colon

Objective: It is known that prokinetic agents increase the motility of stomach and intestine. Although there are many studies on the motility of colon, its mechanism is not well clarified. The aim of this study to investigate the effects of prokinetic agents on proximal and distal colon tissues. Methods: Forty male wistar albino rats were allocated into five groups. Rats divided five group as a control, erythromycin, ampicillin, domperidon and metoclopramide. Before taking the tissue samples, this four agents were given by oral gavage, three times a day. The proximal and distal colon tissues were taken after the sacrification of rats, the colonic segments were mounted in 10 ml organ baths in the direction of circular muscles, and the contractions were recorded by a polygraph. The changes in the amplitude (% of KCl) and frequency (number/min) of contractions were analyzed before and after the addition of antagonists. The antagonist responses were taken by L-NNA, indomethacin, nimesulid, hexamethonium and tetradotoxin. Results: While investigating the mechanism of the contraction changes, L-NNA, indomethacin, nimesulid significantly increased the amplitude of both proximal and distal colon spontaneous contractions compared with control group but hexamethonium and tetradotoxin did not. According to the frequency responses, the erythromycin group responses were significantly higher than control group. Conclusions: Erythromycin, ampicillin, domperidon and metoclopramide may be useful to increase the motility of gastrointestinal system. On the other hand, the use of these agents in combination with nitric oxide synthase inhibitors and prostaglandin synthesis inhibitors may increase the effects of these agents. Key words: Prokinetic agents, colon, motility, amplitude, frequency