L-精氨酸预防大鼠应激性溃疡的机制研究

目的 探讨一氧化氮（NO）在大鼠应激性溃疡（SU）中的作用及L-精氨酸的预防机制。方法 采用冷束缚法制备大鼠应激性溃疡模型，中性红清除率法测定大鼠胃粘膜血流量。观察预先给予L-精氨酸、L-NAME（硝基精氨酸甲酯，处理后大鼠胃粘膜血流量（GMBF）、溃疡指数（UI）、溃疡坏死组织和中性粒细胞浸润严重程度的变化，同时测定胃粘膜和血浆NO含量的变化。结果 与正常对照组相比模型损伤组的UI、胃粘膜和血浆NO明显增加，溃疡底部坏死物质和周围组织中中性粒细胞浸润均明显加重，GMBF降低。预先给予L-精氨酸处理，可抑制SU大鼠UI、溃疡底部坏死物质和周围组织中中性粒细胞浸润的增加，增加GMBF以及胃粘膜和血浆NO含量；相反，L-NAME可进一步增加SU大鼠UI、溃疡底部坏死物质和周围组织中中性粒细胞浸润，降低GMBF以及胃粘膜和血浆NO的含量。结论 NO在大鼠应激性溃疡中起重要的保护作用。

The Study of Preventive Mechanism of L-Arginine on Stress Ulcer in Rats

Objective To observe the effects of nitric oxide(NO) on stress ulcer(SU)in rats.Methods The SU model of rats was induced with cold-restraint stress,and gastric mucosal blood flow(GMBF)was measured with the neutral red clearance method.After pretreatment with L-arginine or Nitro-L-arginine methyl ester(L-NAME) in rats,the changes of GMBF,ulcer index(UI) and severity of tissue necrosis and neutrophil infiltration(TN&NI) were observed and gastric mucosal and plasma NO were measured.Results Compared with normal control group,in SU model group the UI,content of NO and degree of TN&NI markedly increased,whereas the GMBF significantly decreased.Pretreatment with L-arginine to the SU rats significantly inhibited the increase of UI and degree of TN&NI but increased the GMBF and NO;by contrast,pretreatment with L-NAME further significantly increased the UI and degree of TN&NI but decreased the GMBF and NO.Conclusion No play an important protective role in occarrence of stress ulcer in rats.