Influence of L-NAME and L-Arg on gastric mucosal tolerant cytoprotection under stress / 中华消化杂志

ABSTRACT

Objective To determine the role of endogenous NO in gastric mucosal tolerant cytoprotection under stress and its possible mechanism. Methods SD rats were exposed to WRS repeatedly during which L NAME, a non selective NOs inhibitor, and L Arg, a substrate for NO synthesis, were administered to inhibit or promote the synthesis of NO, GMBF was measured using LDF 3 flowmeter, NO levels in gastric mucosa were tested by Griess reaction and gastric mucosal lesions were evaluated by ulcer index (UI). Results Gastric tolerant cytoprotection was accompanied by increased GMBF and NO levels 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 caused by WRS. GMBF and NO content in mucosa increased. After 4th WRS, mucosal lesions could be negligible. Conclusion By regulating GMBF, endogenous NO might play an important role in the gastric mucosal tolerant cytoprotection under stress. Inhibition of NO synthesis delayed the induction of tolerant cytoprotection, while increase NO synthesis will ptomote the induction of tolerant cytoprotection.