ROLE OF DORSAL MOTOR NUCLEUS OF VAGUS IN GASTRIC FUNCTION AND MUCOSALDAMAGE-INDUCED BY ETHANOL IN RATS

Experimental evidence indicates that the autonomic nervous system, esp ecially the cholinergic pathway, modulates the mucosal defensive mecha nism and affects mucosal damage in the stomach. The present study inve stigated the role of the dorsal motor nucleus of vagus (DMV) in gastri c function and its influences on ethanol-induced mucosal damage in pen to-barbitone-anesthetized rats. Electrolytic lesion of the DMV as comp ared with sham operation and lesions of other brain areas, eg, nucleus reticular gigantocellularis and cuneate nucleus, reduced the basal ga stric mucosal blood flow (GMBF) and also the blood flow after ethanol administration. The same operation did not affect the acid secretion e ither in the basal state or during the ethanol treatment period. Lesio ns at the caudal half of the DMV produced a bigger depression of GMBF when compared with lesion at the rostral half, In the sham-operated ra ts, ethanol induced severe hemorrhagic lesions in the gastric glandula r mucosa, and this was significantly potentiated by lesions at the DMV , especially in the caudal half. The present findings indicate that ac ute DMV damage at the caudal half markedly affects the GMBF but not th e acid secretion. The action on GMBF may contribute to the aggravation of ethanol-induced gastric damage in rats. These data reinforce the i dea that the central vagal pathway, especially the caudal half of the DMV, plays a significant role in the modulation of GMBF, which in turn affects the integrity of gastric mucosal barrier.