Attenuation of basal gastric acid secretion following the blockade of hypothalamic ventromedial D2 receptors in rats

Abstract

Background: Dopamine plays an important role in regulating gastric acid secretion in the central nervous system. Dopamine D2 receptors of hypothalamic ventromedial nucleus (VMH) are involved in modulation of food intake, suggesting a potential role of the VMH D2 receptor in modulating gastric acid secretion. Hence in this study, we investigated the effect of the VMH D2 receptor blockade on basal gastric acid secretion. Methods: A guide cannula was stereotaxically implanted in VMH of male Wistar rats weighing 220-250 g. The D2 receptors antagonist sulpiride (0.005, 0.050, 0.500, and 1.000 μg/0.5 μl) or saline (0.5 μl) were injected into VMH after a 5-day recovery period. Gastric acid secretion was measured using the pylorus-ligation method and titration with NaOH 0.01 N. Findings: Sulpiride at the doses of 0.050 (P < 0.010), 0.500 (P < 0.001), and 1.000 (P < 0.001) μg/0.5 μl significantly decreased basal gastric acid secretion in a dose-and time-dependent manner. Conclusion: Sulpiride at the dose of 0.500 μg/0.5 μl had maximum effect on the secretion activity of stomach. Blocking VMH D2 receptors decreases the secretion activity of stomach in rats. © 2018, Isfahan University of Medical Sciences(IUMS). All rights reserved.