L-NAME对肝硬化大鼠胃肠道中一氧化氮合酶亚型表达的影响

目的 研究一氧化氮合酶亚型（NOS1，NOS2，NOS3）在肝硬化大鼠胃肠道中的表达，并探讨NOS抑制剂左旋硝基精氨酸甲基酯（L-NAME）对其表达的影响。方法 制作大鼠四氯化碳中毒肝硬化模型，肝硬化模型大鼠随枘发为NO合酶（NOS）抑制剂治疗组和未治疗组，模型治疗组用L-NAME0.5mg.kg^-1.d^-1，胃内注入，每日1次，治疗10d，免疫组织化学染色显示胃肠道组织中型NOS的染色强度和分布，Western blot法检测胃肠道组织中各型NOS的表达。结果 模型组大鼠胃、小肠、结肠组织 的NOS染色强度显著弱于正常对照组和L-NAME治疗组大鼠。Western blot显示在肝硬化模型大鼠胃、小肠、结肠组织中的各型NOS表达均明显降低，L-NAME治疗后又恢复至接近正常。结论 肝硬化大鼠胃肠道组织中各型NOS的表达明显减少，L-NAME对其表达有调节作用。

L-NAME and expression of NOS isoforms in cirrhotic rat intestines

AIM　To investigate the effect of L-NAME on expression of the nitric oxide synthase (NOS) isoforms in the cirrhotic rat intestine. METHODS　Rats with cirrhosis induced by carbon tetrachloride were randomly divided into two groups, one receiving 0.5 mg*kg-1*d-1 of NG-nitro-L-arginine methyl ester (L-NAME) during 10 d, whereas the other group and control were administrated the same volume of saline. Immunohistochemical SABC method was used to observe the expression and distribution of three isoforms of NOS in gastrointestinal tract of rats. Western blotting was used to detect expression of gastrointestinal NOS isoforms. RESULTS　NOS isoforms staining intensities were markedly lower in cirrhotic rat intestine than the control and cirrhotic rats after being treated with L-NAME. CONCLUSION　Expressions of the NOS isoforms were significantly reduced in the cirrhotic rat intestine. Maybe there is a regulation of L-NAME on expression of the gastrointestinal NOS isoforms in cirrhotic rats.