动态监测STAT3、HMGB1在急性肝衰竭大鼠中的变化及意义

目的 观察信号转导子和转录激活因子(STAT3),高迁移率族蛋白B1(HMGB1)在D-氨基半乳糖介导急性肝衰竭模型中的动态变化规律.方法 用D-氨基半乳糖制作大鼠急性肝衰竭模型,用RT-PCR检测STAT3 mRNA,HNCB1 mRNA在急性肝衰竭大鼠肝组织6、12、24、48、72、120和168 h的表达.结果 STAT3 mRNA在急性肝衰竭的6 h有显著升高,与正常组差异有统计学意义(P<0.01),24 h达高峰,在48、72、120 h仍保持较高水平,与正常组比较差异有统计学意义(P<0.01);HMGB1 mRNA在6 h亦显著升高,与正常组比较差异有统计学意义(P<0.01),12 h达高峰,在24、48、72 h仍保持较高水平,与正常组比较差异有统计学意义(P<0.01).ALT和AST在6 h有轻度升高,至24 h与正常组差异有统计学意义(P<0.05),48 h(P<0.01)达高峰,72 h逐渐下降.TBil在6 h开始持续升高,72 h达到高峰(P<0.01),120 h逐渐下降.结论 STAT3、HNGB1可能参与了急性肝衰竭的病理生理过程,可能成为l临床上治疗急性肝衰竭的新靶点.     

丹酚酸B-镁盐抗大鼠D-半乳糖胺肝损伤的作用

应用丹参水溶性活性成分——丹酚酸B-镁盐抗大鼠D-半乳糖胺肝损伤,可显著降低血清丙氨酸氨基转移酶(ALT)、门冬氨酸氨基转移酶(AST)活性,减轻肝细胞坏死。提高肝非实质细胞花生四烯酸代谢产物6-酮基-前列腺素F_(1α)(6-keto-PGF_(1α))、前列腺素D_2(PGD_2)及前列腺素总的生成量。表明丹酚酸B-镁盐可能是丹参抗肝损伤的主要成分,其提高肝非实质细胞前列腺素(PGs)总的生成量可能是其抗肝损伤的机制之一。     

消炎利胆片防治大鼠急性肝损伤的实验研究

目的:研究消炎利胆片(穿心莲、溪黄草、苦木等)对大鼠急性肝损伤的保护作用。方法:分别采用四氯化碳(CC l4)和D-半乳糖胺(D-galactosam ine,D-Gal)腹腔注射造成大鼠急性肝损伤,测定血清生化指标,并测体重和肝脏重、脾重和胸腺重,求脏器系数。同时切取肝脏检测肝糖原,并取肝组织作病理观察。结果:消炎利胆片可显著降低CC l4和D-Gal诱导的急性化学性肝损伤大鼠血清ALT、AST、ALP水平及TBA和T-B il含量。病理检查结果也显示有明显的保肝作用。结论:消炎利胆片对CC l4和D-Gal所致大鼠急性肝损伤有保护作用。     

苦荞麦籽粒提取物对小鼠化学性肝损伤的影响

目的探讨苦荞麦籽粒提取物（FTGE）对肝脏的保护作用。方法FTGE对四氯化碳（CCl4）致急性肝损伤的作用：小白鼠60只，随机分为6组，每组10只。正常对照组、CCl4模型组灌胃给予等量纯化水，阳性对照组灌胃给予联苯双酯200 mg·kg^-1·d^-1，低剂量实验组、中剂量实验组、高剂量实验组分别灌胃给予FTGE 20，40和60 g·kg^-1·d^-1，各组均连续给药7 d。7 d后，除正常对照组外，其他各组小鼠均腹腔注射0.1% CCl4花生油溶液10 mL·kg^-1。禁食16 h，摘眼球取血，分离血清，测试血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）值。FTGE对D-半乳糖胺（D-Galn）致急性肝损伤的作用： 取60只小鼠，雌雄各半，分为6组，每组10只。正常对照组、D-Galn模型组灌胃给予0.9%氯化钠溶液 20 mL·kg^-1·d^-1，阳性对照组灌胃给予联苯双酯15 mg·kg^-1·d^-1，低剂量实验组、中剂量实验组、高剂量实验组分别灌胃给予FTGE 20，40和60 g·kg^-1，各组连续灌胃给药12 d，于末次给药后1 h，除正常对照组外，其他各组均腹腔注射10%D-Galn 800 mg·kg^-1，小鼠于腹腔注射D-Galn后禁食过夜，待16 h后断头处死动物。结果FTGE对CCl4和D-Galn导致的急性肝损伤小鼠有非常显著的降酶作用(P＜0.01)，且剂量越大，降酶作用越强。结论苦荞麦籽粒提取物对化学性肝损伤小鼠有明显的保护作用。     

黄芩苷固体分散体对小鼠D-氨基半乳糖急性肝损伤的保护作用

目的研究黄芩苷固体分散体对小鼠D．氨基半乳糖（D—GaIN）急性肝损伤的保护作用,并与单纯黄芩苷进行比较。方法60只小鼠随机分为正常组、D—GaIN模型组（模型组）、联苯双酯[200mg／（kg·d）]组、黄芩苷[50mg／（kg·d）]组,以及黄芩苷固体分散体低、高剂量[分别为50、100mg／（kg·d）]组。正常组和模型组小鼠给予0．5％CMC．Na20mL／kg灌胃,其他组小鼠给予相应药物灌胃。各组分别灌胃给药7天后,通过腹腔注射D．GaIN诱导急性肝损伤模型,计算小鼠肝脏、脾脏指数,测定血清中谷丙转氨酶（ALT）、谷草转氨酶（AST）活性及肝匀浆中超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量,HE染色观察肝组织病理学变化。结果与正常组比较,模型组小鼠肝组织炎症坏死广泛,肝脏指数及血清ALT、AST活性升高,肝组织中SOD活性降低,MDA含量升高,差异均有统计学意义（P〈0．05）。与模型组比较,黄芩苷固体分散体低、高剂量组及联苯双酯组小鼠肝脏指数及血清ALT、AST活性降低,肝组织中SOD活性升高,MDA含量降低,肝组织损伤程度显著改善,且黄芩苷固体分散体低剂量组明显优于同等剂量黄芩苷组,差异均有统计学意义（P〈0．05）。结论黄芩苷固体分散体对D．GaIN诱导的小鼠急性肝损伤具有明显保护作用,且效果优于单纯黄芩苷。     

山茱萸环烯醚萜苷对D-GalN/TNF-α损伤肝细胞的保护作用研究

目的研究山茱萸环烯醚萜苷(CIG)对D-Gal N联合TNF-α造成的肝细胞损伤模型的保护作用。方法提取并分离、制备CIG;体外培养人源性肝细胞L-02,建立D-Gal N/TNF-α致L-02细胞损伤模型,以总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、丙二醛(MDA)、细胞内钙离子浓度为指标,观察CIG对损伤肝细胞的保护作用;Western blot检测p-PERK、p-e IF-2α、caspase-3蛋白的表达,进行机制研究。结果44 mg·L^-1D-Gal N联合100μg·L^-1TNF-α可作为细胞损伤模型的剂量。CIG高、中、低剂量预保护组可明显提高损伤细胞的活性,明显提高损伤细胞的SOD活性、T-AOC能力,与模型组比较差异具有显著性(P<0.05),降低MDA活性,但低浓度组对MDA活性的降低不明显;Western blot结果显示,CIG不同浓度组可以明显降低内质网应激关联蛋白p-PERK、p-e IF-2α、凋亡关联蛋白caspase-3表达。结论山茱萸环烯醚萜苷对D-Gal N/TNF-α造成的肝细胞损伤具有保护作用,其作用机制可能与增强细胞的抗氧化能力,降低内质网应激造成的损伤,降低凋亡相关蛋白的表达有关。     

Effect of PGE1 on TNF-alpha status and hepatic D-galactosamine-induced apoptosis in rats

Prostaglandin E1 has hepatoprotective properties in several clinical and experimental models of liver dysfunction. Hepatotoxicity induced by D-galactosamine (D-GalN) is a suitable animal model of human acute hepatic failure. The aim of the study was to investigate if prostaglandin E1 (PGE1) protection against hepatic D-GalN-induced apoptosis was related to tumour necrosis factor-alpha (TNF-alpha) content in serum. This cytokine is associated with in vitro apoptosis and general inflammatory disorders. In this study, PGE1 was administered 30 min before D-GalN to rats. In other experiments, several doses of TNF-alpha were administered 15min after PGE1 to D-Ga1N-treated rats. Several parameters related to apoptosis and necrosis were measured by flow cytometry, gel electrophoresis, biochemical analysis, and optical and electron microscopy. Tumour necrosis factor-alpha was quantified by competitive enzyme-linked immunosorbent assay (ELISA). PGE1 by itself did not modify the cell cycle of hepatocytes and liver toxicity, but increased TNF-alpha in serum in comparison with the control group. D-Galactosamine increased the percentage of hepatocytes in apoptosis and in the S phase of the cell cycle, and decreased those in G0/G1. Such an increase of hepatocytes in apoptosis was correlated with a higher number of apoptotic bodies and DNA fragmentation in liver than control samples. Also, D-GalN increased alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase and TNF-alpha in serum compared with the control group. Pre-administration of PGE1 to D-GalN-treated rats reduced all the parameters of apoptosis and necrosis in liver, and increased additionallyTNF-alpha content in serum. In those experiments where low doses of TNF-alpha were administered to PGE1 and D-GalN-treated rats an inverse relationship appeared between TNF-alpha and ALT content in serum. In conclusion, the protective effects of PGE1 on D-GalN-induced apoptosis may be linked to its capacity to modulate cell division and/or its immunomodulatory activity. In this sense, our experimental results suggest that TNF-alpha could be involved in protection or exacerbation of liver damage in relation to the pathophysiological status of the liver.     

Mature hepatocytes actively divide and express gamma-glutamyl transpeptidase after D-galactosamine liver injury

Abstract: Aims/Background: We studied the fate of hepatocytes in the rat liver after D-galactosamine injury by genetic labeling using recombinant retroviruses carrying the Escherichia coli lacZ gene coupled to a nuclear localization signal. Methods: Hepatocytes were either labeled by direct injection of 2.5 ml high-titer retrovirus-containing medium in the regenerating liver parenchyma after administration of a single dose of D-galactosamine. Alternatively hepatocytes were pre-labeled, 24 h after a two-thirds hepatectomy, by injecting the same volume of retroviral solution in the portal vein and D-galactosamine was administered 15 days later. Gammaglutamyl transpeptidase and β-galactosidase activities were assessed on cryostat sections, along with localization of the hepatocyte-specific HES6 antigen. Results: Morphological observations, as well as β-galactosidase activity detection, showed that hepatocytes actively divide as early as 1 day after D-galactosamine injection. Gamma-glutamyl transpeptidase activity was detected in biliary cells, but also in mature hepatocytes, prelabeled with β-galactosidase before D-galactosamine administration. Conclusions: These experiments demonstrate that hepatocytes can divide to restore the liver mass after D-galactosamine liver injury. Furthermore, we also show that gamma-glutamyl transpeptidase, which has been reported to be expressed only by fetal or preneoplastic hepatocytes, can be re-expressed by mature hepatocytes during the recovery process.