iNOS抑制剂SMT对内毒素血症大鼠淋巴管动力学的影响

目的 :研究一氧化氮 (NO)在急性内毒素血症中对淋巴管运动的调节作用及诱生型一氧化氮合酶 (iNOS)抑制剂硫酸甲基异硫脲(SMT)对内毒素血症中淋巴微循环的作用。方法 :用倒置显微镜和图像处理系统对肠系膜淋巴管进行动态观测 ,并用硝酸还原酶法测定血清中NO的含量。结果 :LPS组肠系膜淋巴管管径比正常扩大 ,运动频率降低 ,淋巴管运动指数下降。LPS +SMT组则有显著改善。随时间延长LPS组血清NO含量显著升高 ,LPS +SMT组则有明显下降。结论 :内毒素血症中NO过量产生 ,使肠系膜淋巴管扩张 ,收缩减弱。内毒素血症早期应用iNOS抑制剂SMT可维持淋巴微循环于正常水平。

Effects of iNOS Inhibitor SMT on Motion of Rat Lymphatic Vessels

Objective: To study the dynamic changes of lymphatic vessels during acute endotoxemia and the effects of selective inducible nitric oxide synthase(iNOS) inhibitor S methylisothioure(SMT) on rat mesenteric lymphatic motion in vivo.Method: Using inverted microscopy and digital image processing to observe and measure the diameters and motive indexes of the rat mesenteric lymphatic vessels and measure the content of NO in plasma.Results: The mesenteric lymphatic diameters(including average,maxium,minimum caliber) in LPS group were greater than those before injection;motive frequency and motive indexes were decreased.There were no obvious changes among lymphatic diameter,motive frequency,motive indexes in LPS+SMT group.The plasma NO content was more significantly increased in LPS group than control,but it was decreased in LPS+SMT group compared with LPS group.Conclusion: During endotoxemia,the overproduction of NO can cause the dilation of mesenteric lymphatic vessels and the decrease of contractile indexes.During the early stage of endotoxemia,selective iNOS inhibitor SMT can maintain lymphatic microcirculation at normal condition.