Dual effects on gastric acid secretion of electrical stimulation of anterior parts of the rat hypothalamus.

The effect of electrical stimulation of anterior parts of the hypothalamus on gastric acid secretion was examined in rats anesthetized with urethane. Electrical stimulation (0.5 mA, 2 msec, 10 Hz, for 10 min) of the lateral hypothalamic area (LHA) induced a marked increase in basal gastric acid output. Electrical stimulation of the preoptic area (PO), the paraventricular nucleus (PVN) and the anterior hypothalamus (AH) also induced increases in basal acid secretion. Electrical stimulation of the PO, PVN and AH inhibited the increase in acid secretion induced by electrical stimulation of the vagus nerve (1 mA, 0.5 msec, 3 Hz). These inhibitory effects were abolished by bilateral cutting of the splanchnic nerves. On the other hand, the stimulation of the LHA had no effects on vagally stimulated gastric acid secretion. Electrical stimulation of the anterior parts of the hypothalamus induces dual effects, vagally mediated increases in basal gastric acid output and splanchnic mediated inhibition of the vagally stimulated gastric acid output.