Morphine inhibits the gastric acid secretion stimulated by 2-deoxy-D-glucose via a central mechanism in anesthetized rats.

The effect of morphine on the gastric acid secretion induced by 2-deoxy-D-glucose (2-DG) was investigated in the perfused stomach of anesthetized rats. The intravenous infusion of morphine (0.01-1.0 mg/kg per h for 2 h) dose dependently suppressed the gastric acid secretion stimulated by 2-DG. This inhibitory effect of morphine was completely reversed by naloxone (1.0 mg/kg i.v.) pretreatment. On the other hand, even the higher dose of morphine (1.0 mg/kg per h for 70 min) had no effect on the gastric acid secretion evoked peripherally by electrical stimulation of the vagus nerve. These observations indicate that morphine suppressed the 2-DG-induced gastric acid secretion via a central mechanism(s), probably mediated by the opiate receptor(s).