蛋白激酶C对内毒素休克大鼠肝损伤诱导型一氧化氮合成酶表达的调控

目的　探讨蛋白激酶C(PKC)对内毒素休克大鼠肝损伤诱导型一氧化氮合成酶 (iNOS)表达的调控。方法　将大鼠随机分为 6组 ,分别为正常对照组、脂多糖 (LPS)组、LPS +琼脂糖 (AG) (10 0mg/kg)组、LPS +H7小剂量 (12 .5mg/kg)组、LPS +1(5 异喹啉磺酰基 ) 2 甲基哌嗪 (H7)大剂量 (2 5mg/kg)组、LPS +H7+佛波醇乙酯 (PMA) (3mg/kg)组。注射药物后观察其血压及血清学、苏木素 伊红 (HE)染色、免疫组织化学染色、iNOS蛋白活性检测、WesternBlotting免疫印迹法检测iNOS等指标。 结果　①血压及血清学 :AG升压迅速且持续 ;H7也有升压作用。②组织学 :LPS可致肝组织呈弥漫性病变 ,H7能改善LPS所致的肝损伤。③iNOS免疫组织化学 :正常组iNOS染色阴性 ,LPS组iNOS强阳性表达 ;H7能抑制iNOS表达 ,但不如AG明显。④iNOS蛋白活性检测 :LPS可致iNOS活性显著增强 (P <0 .0 1) ,H7可抑制iNOS ,与剂量相关 ,并可被PMA逆转 ,但AG抑制作用最强。⑤iNOSWesternBlotting免疫印迹观察 :正常组iNOS条带缺如 ,H7对iNOS表达有抑制作用 ,而AG组对iNOS抑制作用最强。结论　PKC可能参与内毒素诱导的iNOS表达 ,但不同于AG的是 ,H7能改善肝功能。故抑制PKC活性可更广泛地减轻内毒素条件下炎症所致的肝损伤 ,从而对内毒素所致的脏器衰?

Protein kinase-C on the expression of inducible nitric oxide synthase in rats with liver injury induced by endotoxin shock

Objective To investigate the molecular mechanism of inducible nitric oxide synthase(iNOS) gene expression in injured rat′s liver caused by endotoxin shock.Methods The rats were randomly divided into normal control group,LPS treatment group, LPS+AG group(100 mg/kg),LPS+H7 low dosage group(12.5 mg/kg),LPS+H7 high dosage group(25 mg/kg) and LPS+H7+PMA group(3 mg/kg). The changes of BP and serological markers,the HE staining and immunohistochemical staining of livers and protein activity of iNOS measured by western immunoblot were observed.Results ①BP and serological analysis: BP increased significantly and rapidly after AG injection. H7 also had the effect of BP increment.②Histological changes:LPS led to diffusely pathological changes of rats hepatocellular tissues, however,those effects could be reversed by H7.③Immunohistochemical staining of iNOS:with the treatment of LPS,thestrongpositiveexpressionofiNOS in rats hepatocells was observed compared with the negative expression of iNOS in normal control group. H7 could down-regulate the expression of iNOS, but not as significant as AG treated group. ④Detection of iNOS protein activity: LPS could activate the iNOS evidently (P<0.01).H7 inhibited the iNOS expression with dosage dependence, but could be reversed by PMA. AG had the strongest effect on the iNOS inhibition.⑤iNOSwesternblotting:NOiNOSproteinexpressionwasfoundinnormalcontrolgroup, and the positive blot of iNOS was observed in LPS group.H7 and AG could antagonize the iNOS expression induced by LPS,but AG had the strongest effect.Conclusion Protein kinase-C (PKC) may play an important role in the expression of iNOS induced by endotoxin.H7 can improve the function of liver, which is distinguished from AG. Down-regulation of PKC activity can relieve the liver injury caused by inflammation in endotoxin condition, and avoid the organ failure induced by endotoxin.