脂多糖诱导山羊肝脏TNF-α分泌特点的研究

目的:为了研究肝脏在实验性内毒素血症中的免疫调节作用。方法:采用17只雄性去势山羊,外科手术方法装置颈静脉插管、肝静脉插管和门静脉插管。手术4 d后,分3个组进行实验:组①经门静脉灌注20 EU/kg体重的LPS;组②经颈静脉灌注20 EU/kg体重的LPS;组③经颈静脉灌注1 500 EU/kg体重的LPS。灌注前和灌注8 h内定时采集颈静脉、肝静脉和门静脉血样,采用放射免疫测定法测定血样中TNF-α的含量变化。结果:在组①肝静脉和门静脉血TNF-α水平于5 h上升到峰值,颈静脉动血则基本无变化。在组②颈静脉、肝静脉血于1 h和3 h上升达到峰值,而门静脉血TNF-α水平则在0-8 h期间持续上升。在组③肝静脉、门静脉和颈静脉血中TNF-α在1h同步迅速达到峰值。结论:肝脏在内毒素血症时TNF-α的分泌依脂多糖进入的途径和剂量而有不同的分泌特点。

Characteristics in the secretion of liver TNF- α induced by infusion of LPS into veins in goats

AIM: To study the role of liver in immune regulation in experimental endotoxemia. METHODS: 17 castrated male goats were subjected to simultaneously installing catheters in jugular, hepatic and portal veins by surgery. Four days later, lipopolysaccharide (LPS) was infused in term of three groups as followings: In group ①, LPS of 20 EU (endotoxin unit, EU)·kg^-1 was infused into portal vein; In group ②, LPS of 20 EU·kg^-1 was infused into jugular vein and LPS of 1 500 EU·kg^-1 infused into jugular vein in group ③. Before and after infusion, blood samples were collected from the three veins through the catheters for 8 h.The plasma levels of TNF-α were measured by RIA. RESULTS: In group ①, the plasma TNF-α levels of hepatic and portal vein rose to peak value at 5 h, but that of the jugular vein did not changed. In group ②, the plasma TNF-α levels in hepatic vein rose to peak value at 3 h. The TNF-α levels of jugular vein rose to peak value at 1 h and the one in portal vein enhanced continuously between 0-8 h. In group ③, the plasma TNF-α levels in jugular, hepatic and portal vein rose to significant peaks at 1 h simultaneously. CONCLUSION: During experimental endotoxemia,liver showed different dynamic characteristics in TNF-α secretion according to the pathway and doses of LPS delivery.