The effects of acute exposure to cigarette smoke and systemic administration of nicotine on intestinal propulsion were investigated in rats. The propulsive activity was measured as migration of charcoal powder in the intestine. This activity was suppressed by acute exposure (10 min) to cigarette smoke and by nicotine (0.5 mg/kg x 2, s.c.) administration. This intestinal suppression was more marked in the rats given nicotine than in those exposed to cigarette smoke, whereas the plasma concentrations of nicotine in both rats were similar. These results suggest that acute exposure to cigarette smoke and nicotine administration delay gastric emptying and/or suppress intestinal propulsion, and that some components other than nicotine contained in cigarette smoke may attenuate the suppression of intestinal propulsion induced by nicotine.
