Effects of intracerebroventricularly applied nicotine on enhanced gastric acid secretion and mucosal blood flow in rats.

The effects of intracerebroventricularly administered nicotine on the elevated levels of gastric acid output and mucosal blood flow (MBF) were examined in anesthetized rats. Intravenous administration of both 2-deoxy-D-glucose (2-DG) and pentagastrin induced marked increases in gastric function and the intraventricularly applied nicotine diminished the increases induced by 2-DG but not those due to pentagastrin. This effect of nicotine was inhibited when hexamethonium was given concomitantly. In reserpinized rats, this inhibitory effect of nicotine on the 2-DG-induced increases in gastric function was abolished. Electrical stimulation of the lateral hypothalamic area induced increases in gastric function and these increases were also inhibited by intraventricularly administered nicotine. These results indicate that centrally administered nicotine has an inhibitory effect on both acid secretion and MBF, when these gastric parameters are maintained at relatively higher levels by central activation. Central noradrenergic inhibitory mechanisms in the regulation of gastric function may relate to the inhibitory effects of nicotine.