Neurohumoral pathways mediating stress-induced inhibition of gastric acid secretion in rats.

In awake rats, physical restraint inhibited pentagastrin-stimulated gastric acid secretion by more than 50%. This inhibitory effect was abolished by either ganglionic or noradrenergic blockade. Adrenalectomy, as well as pretreatment with a vasopressin V1-receptor antagonist, significantly attenuated the gastric inhibitory effect in response to stress. In contrast, neither truncal vagotomy nor hypophysectomy or opiate blockade prevented stress-induced inhibition of gastric acid secretion. These findings indicate that stress-induced inhibition of gastric acid secretion in rats is mediated by autonomic, noradrenergic efferents as well as by adrenal and vasopressin-dependent pathways. Vagal efferents, opiate pathways, and the pituitary gland do not seem to be involved.