PROTECTIVE ROLE OF THE ADRENAL-MEDULLA AGAINST RESERPINE-INDUCED GASTRIC-ULCERS IN RATS

The influence of bilateral adrenalectomy or adrenal demedullation (carried out 48 h beforehand) on the 2-h gastric effects of i.p. injected reserpine (5 mg/kg) was studied in rats. Adrenalectomy or demedullation increased the severity of reserpine-induced gastric glandular lesions. Neither ablation method affected the stomach wall mast cell population nor the degree of reserpine-evoked mast cell degranulation. In contrast, both adrenalectomy and demedullation augmented druginduced glandular mucosal microcirculatory dilatation and engorgement. These results suggest that adrenal medullary catecholamines may antagonise, by a vasoconstrictor effect, the gastric glandular mucosal microcirculatory dilatation and congestion which are largely responsible for reserpine ulcers in the rat stomach. This protective effect is, however, overshadowed by the intense ulcerogenic action of the drug. © 1979 The Italian Pharmacological Society.