Experimental Study on the Pituitary Adrenal Axis and the Gastric Secretion Part II. The Central Stimulating Effect on the Gastric Secretion

1) As the central stimulant route for the gastric secretion, the vagus nerve and the pituitary adrenal axis have been recognized. Also in this experiment the influence of these two routes upon the volume of the gastric juice and the concentration of hydrochloric acid were separately compared on the pylorus-ligated rats. 2) For the stimulation of the adrenal axis was used the administration of adrenocorticotropin (ACTH) or psychic stress, and for the stimulation of the vagus nerve, the administration of insulin and pilocarpine. 3) On the other hand, operatively, the vagotomy and adrenalectomy or hypophysectomy were done. 4) Following the adrenalectomy the acidity was profoundly depressed, but the decrease in volume of the whole gastric secretion was slight compared to the acidity. This hypacidity by adrenalectomized rat, however, did not recovered by the prolonged cortisone administration. The positive stimulation by the administration of ACTH increased predominantly the concentration of hydrochloric acid. 5) The effect of bilateral vagotomy lowered significantly the volume of the gastric secretion, but the decrease of free acidity was small compared to the former. The insulin administration increased highly the volume of secretion. and slightly the acidity. 6) Concerning to the central stimulating effect on the gastric secretion, the first route, the vagus nerve, has been considered to be chiefly a hypersecretion-promotive route and the second route, the pituitary adrenal axis, to be chiefly a hyperacidity-promotive route.