Effect of elevated intra-abdominal pressure on the contractile activity and reactivity of smooth muscle tissue from rat gastrointestinal tract to galantamine and drotaverine (No-Spa).

AIM The aim of the present study was to determine the nature and intensity of changes in the contractile activity and reactivity of gastrointestinal smooth muscle tissue in conditions of increased intra-abdominal pressure. METHODS A method for recording isometric contractions of isolated smooth muscle preparations from gastric corpus, duodenum and sigmoid colon of rats was used. RESULTS Two groups of rats were used in the study--control animals and animals with elevated abdominal pressure. It was established that pressure of 25 mmHg for 60 min did not cause statistically significant change in the tone and parameters of the spontaneous contractions in all preparation types, as well as in their reactivity to drotaverine (no-spa). Statistically significant increase in the strength of the tonic effects of galantamine (1.10(-6)-1.10(-3) mg/ml) was found in all types of smooth muscles preparations isolated from rats with increased abdominal pressure compared with preparations from the control rats. CONCLUSIONS The statistically significant increase in the galantamine-induced effects on smooth muscle preparations is associated with increase in the contractile effectiveness of acetylcholine. M-type cholinergic receptors are predominantly involved in the processes, probably sensibilized from processes activated by the increased intra-abdominal pressure.