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目的 :观察脂多糖 (L PS)在大鼠肝脏中诱导磷脂酶 A2 (PL A2 )亚型的激活和基因表达情况。方法 :大鼠腹腔注射脂多糖 (L PS,2 mg/ kg)后不同时间取血 ,分别测定分泌型 PL A2 (s PL A2 )活性和前列腺素 E2(PGE2 )含量 ,用 Western blot检测肝脏中胞浆型 PL A2 (c PL A2 )蛋白的表达和时间进程 ;采用免疫组化法检测s PL A2 和 c PL A2 蛋白在肝脏中的表达 ;用 m RNA斑点杂交法检测 s PL A2 、c PL A2 m RNA在脏器中的转录水平。结果 :L PS可以时间依赖方式升高大鼠血清 s PL A2 活性、PGE2 含量以及肝脏中 c PL A2 蛋白表达 ;免疫组化显示肝细胞可表达两类 PL A2 ,且 L PS可加强其表达 ;肝脏及其它脏器中均有两类 PL A2 m RNA转录 ,受 L PS刺激后反应各不相同 ,而在肝脏中均有加强。结论 :L PS可明显增强大鼠肝脏中两类 PL A2 的基因转录和蛋白表达 ,同时可引起血中 PL A2 活性增高和花生四烯酸代谢产物明显增高 ;肝脏可能是炎性反应中外周血 PL A2活性及脂类介质的主要来源 ,L PS对肝脏中两类 PL A2 的诱导可能成为促进全身性过度炎性反应的启动因素
Objective: To observe the activation and gene expression of phospholipase A2 (PL A2) subtype induced by lipopolysaccharide (LPS) in rat liver. Methods: The rats were injected intraperitoneally with lipopolysaccharide (LPS, 2 mg / kg) at different times and the levels of secreted PL A2 (s PL A2) and prostaglandin E2 (PGE2) were measured respectively. The expression and time course of cytosolic PL A2 (c PL A2) protein were detected by immunohistochemistry. The expression of sPL A2 and c PL A2 protein in the liver was detected by immunohistochemistry. The sPL A2, c PL A2 m RNA transcription level in organs. Results: LPS could increase s PL A2 activity, PGE2 content and c PL A2 protein expression in the liver in a time-dependent manner. Immunohistochemistry showed that two types of PL A2 were expressed in hepatocytes, and L PS could enhance its expression. There are two types of PL A2 m RNA transcripts in other organs, which respond differently after LPS stimulation but are enhanced in the liver. CONCLUSION: L PS can significantly enhance the gene transcription and protein expression of two kinds of PL A2 in rat liver, and at the same time, it can cause PL A2 activity increase and arachidonic acid metabolites in blood significantly increase; liver may be inflammatory reaction in peripheral blood PL A2 activity and the main source of lipid mediators, the induction of two classes of PL A2 in the liver by L PS may be a trigger for systemic over-inflammatory responses