Involvement of nicotinic receptors in the dorsal motor nucleus of the vagus in regulation of gastric motility in rats.

Roles of nicotinic receptors in the dorsal motor nucleus of the vagus (DMV) in the regulation of gastric motility were investigated in urethane-anesthetized rats in which an intragastric balloon had been placed. Nicotine (0.1 nmole) microinjected into the DMV but not the nucleus ambiguus induced dual changes, a decrease followed by an increase in gastric motility. Administration of 0.1 nmole of hexamethonium into the DMV significantly inhibited the decrease in gastric motility induced by intravenously administered nicotine.