急性内毒素血症早期大鼠肠系膜淋巴管的动态观察

The Viviperception of Rat Mesenteric Lymphatic Motion in Early Acute Endotoxemia

目的利用活体微循环显微闭路电视系统 ,研究内毒素作用下肠系膜淋巴管的运动变化 ,探讨内源性NO对淋巴管的作用。方法Wistar大鼠分三组 ,于股静脉一次性推注:⑴内毒素(脂多糖 ,lipopolysaccharide ,LPS) ;⑵一氧化氮合酶(NOS)抑制剂N -硝基 -L-精氨酸甲基酯(L -NAME) ;⑶LPS及L -NAME。观察注药前和注药后2h内的肠系膜淋巴管管径、收缩频率等指标。结果⑴LPS组:肠系膜淋巴管管径较注药前扩大 ,运动频率减少 ,总收缩活性指数变小 ;⑵L -NAME组:淋巴管管径变细、运动频率增加、收缩分数变大 ;⑶LPS +L -NAME组:淋巴管管径、运动频率、运动指数2h内变化不显著。结论内毒素血症早期肠系膜淋巴管扩张、收缩减弱 ,同时应用L -NAME可抑制该变化 ,单独应用L -NAME则使淋巴管缩窄、收缩加强 。

Objective Using an intravital video microscope system,to study the changes of mesenˉteric lymphatic pump activity affected by endotoxin and the endogenous nitric oxide(NO)on lymphatic vesˉsels.Methods Wistar rats were divided into3groups and injected with lipopolysaccharide(LPS)、NOS inˉhibitor L-N(G)-nitro-arginine-methyl-ester(L-NAME)and both through femoral vein.We observed the mesenteric lymphatic pump activity before(as normal)and2hours after the injection in vivo.Results(1)LPS group:the mesenteric lymphatic vessel was dilated;pumping frequency and contractive index II were deˉcreased.(2)L-NAME group:the lymphatic diameter was narrowed while motive frequency was increased;conˉtractile index I increased.(3)LPS+L-NAME group:there were no obvious changes among lymphatic diameter,motive frequency and contractile indexes compared with those of normal within2hours.Conclusions In early acute endotoxemia,mesenteric lymphatic vessels are dilated with weakened contractile activity.These can be suppressed by applying L-NAME simultaneously.L-NAME alone can decrease lymphatic diameter and increase contractility.It suggests that NO plays an important role in maintaining normal lymphatic pump activity and in adapting lymphatic circulating changes in early phase of endotoxemia.