REGULATING ROLE OF ENDOGENOUS NITRIC OXIDE IN GASTRIC MUCOSAL BLOOD FLOW AND TOLERANT CYTOPROTECTION UNDER STRESS / 解放军医学杂志

ABSTRACT

To determine the role of GMBF in gastric mucosal tolerant cytoprotection under stress and its possible regulator, SD rats were exposed to repeated WRS, during which L NAME , a non selective NOS inhibitor, or L Arg, a substrate for NO synthesis, was administered to inhibit or promote the synthesis of NO, GMBF was measured using LDF 3 Flowmeter, NO level in gastric mucosa was monitored by Griess reaction, and gastric mucosal lesions were evaluated by UI. The results showed that gastric tolerant cytoprotection was accompanied by increased GMBF and NO level in gastric mucosa. Inhibition of endogenous NO synthesis by L NAME worsened mucosal lesions induced by WRS. After repeated WRS, adaptive increase of GMBF was abolished and NO content in gastric mucosa significantly reduced. In contrast, enhancement of endogenous NO synthesis by L Arg attenuated mucosal erosions produced by WRS and GMBF, NO content in mucosa increased. Good relationships between the changes in GMBF, UI, NO content in mucosa were found. It suggested that GMBF might play an important role in gastric mucosal tolerant cytoprotection. Endogenous NO might be one of its regulators. Inhibition of its synthesis delayed the induction of tolerant cytoprotection, while enhancementpromoted it.