[Effect of catecholaminergic agonists and antagonists on adaptive gastric mucosal protection in rats]

The gastric mucosal damage caused by 70% ethanol significantly decreased in rats pretreated with chronic mild restraint stress (CMRS, P < 0.001). This adaptive mucosal protection induced by CMRS was absent in sympathectomized rats, while the administration of isoprenaline or dopamine could partially, and norepinephrine could not, restore the protection. In rats with rntact sympathetic nerve, preinjection of haloperidol or propranolol inhibited CMRS-induced protection which, however, was not affected by phentolamine. No change in plasma somatostatin level was observed either in stress or sympathectomized rats alone or in stress plus sympathectomized rats. The results suggest that the sympathetic nerve or its mimetic agent ang this is are involved in the adaptive protection of the gastric mucosa possibly mediated through beta and dopamine receptors.