大鼠慢加急性肝衰竭模型肝脏组织病理学特征研究

目的 探讨大鼠慢性肝病基础上诱导的急性肝衰竭(慢加急性肝衰竭)模型肝脏组织病理学动态特征.方法 购入雄性SD大鼠,以50%四氯化碳植物油溶液腹腔注射,每3天1次,连续3个月(第一个月1.5 mL/kg体质量,第2、3个月 2.0 mL/kg体质量),建立大鼠肝硬化模型,对照组腹腔注射植物油溶液.肝硬化模型成立后,腹腔注射2 g/kg体质量D-氨基半乳糖(D-Galactosamine,D-Gal),建立肝硬化基础急性肝衰竭模型,并动态进行病理染色及电镜观察.结果 大鼠慢加急性肝衰竭模型制备良好,所有大鼠出现明显的腹水及黄疸症状,出现假小叶结构及细胞凋亡等.D-Gal急性攻击后,短时间内出现组织水肿、脂肪变性明显,大片嗜酸性变性.电镜上开始胞浆疏松、亚细胞器变形、糖原减少等,逐渐出现细胞器变少、异性结构、核固缩等现象.最终整个细胞器形态结构破坏,碎屑样小体出现及细胞溶解坏死.结论 肝硬化基础上药物急性攻击时除了细胞凋亡外,中毒所引起的溶解坏死后期参与大量肝细胞死亡.     

采用免疫型肝硬化大鼠建立慢加急性肝衰竭模型方法的研究

目的对人血清白蛋白免疫诱导型肝硬化大鼠给予不同急性打击，探索建立与人慢加急性肝衰竭组织病理表现相似、实用性、重复性好的实验模型、方法用人血清向蛋白免疫诱导建立肝硬化大鼠模型，至肝纤维化达4级时随机分组，组一（n=6）给予1．2g／kg的D．氨基半乳糖腹腔注射；组二（n=6）给予30mg／kg脂多糖尾静脉注射；组i（n=6）给予D-氨基半乳糖400mg／kg＋脂多糖100trg／kg同时腹腔注射；组四（n：4）继续给人血清白蛋白静脉注射，计算每组动物自然生存时间及死亡率、观察各脏器组织病理变化。结果组一5只大鼠给药后39～52h之内死亡，肝组织病理显示肝硬化基础上发生弥漫大小泡脂肪变性，仅见小片坏死灶；组二大鼠均存活良好，给药后3天后处死肝组织未见坏死性病变。组三5只大鼠在13～19h内死亡，肝脏病理表现为再生结节大块或亚大块坏死，肝细胞凋广明硅，增生的纤维间隔完整保留。结论对人血自蛋白免疫诱导型肝硬化大鼠给予D-氨基半乳糖／脂多糖联合急性攻击可建立慢加急性肝衰竭模型，而单独给大剂量D-氨基半乳糖或脂多糖不能使肝硬化大鼠发生肝脏大块或亚大块坏死。     

肝硬化大鼠急性肝衰竭时Th1/Th2细胞因子、氧化应激及Casapase-3的变化

目的 观察肝硬化大鼠急性肝衰竭时Th1/Th2细胞因子、氧化应激指标及casepase-3的变化,以探讨肝硬化大鼠急性肝衰竭发生的机制.方法 以50%四氯化碳植物油溶液腹腔注射,建立大鼠肝硬化模型.肝硬化大鼠腹腔注射D-氨基半乳糖,建立肝硬化基础急性肝衰竭模型.采用ELISA法测定成模大鼠Th1/Th2细胞因子的比值及Caspase-3,应用生化法检测氧化应激指标[超氧化物歧化酶(SOD)、丙二醛(MDA)及还原型谷胱甘肽(GSH)].结果 大鼠出现明显肝硬化、腹水及黄疸症状后,Th1/Th2细胞因子比值降低.急性肝功能衰竭发生后,Th1/Th2比值升高,Caspase-3活性增加,MDA含量增加,SOD、还原型GSH活性降低(P均＜0.01).结论 Th1/Th2细胞因子、细胞凋亡、细胞氧化应激共同参与肝硬化基础急性肝衰竭的发生.     

珍珠梅水提取物对D-半乳糖中毒大鼠急性肝损伤的防护作用

目的：研究珍珠梅水提取物对D-半乳糖所致大鼠急性肝损伤的防护作用。方法：50只大鼠随机分为正常组、模型组、大和小剂量给药组、阳性对照纽5个组。给药组按10g／k、5g／k剂量以珍珠梅水提取物灌胃；阳性对照组按0．2g／k剂量以联苯双酯灌胃；正常组、模型组以等体积生理盐水灌胃；共5天。第4天，模型组和给药组按0．5g／kg剂量腹腔注射D-半乳糖，正常组腹腔注射等体积生理盐水。腹腔注射D-半乳糖24小时后，摘眼球取血，用比色分析法测定大鼠血清AST、ALT的活性，血清和线粒体超氧化物歧化酶(superoxide dismutase，SOD)、谷胱甘肽过氧化物酶(glutathione perioxidase，GSH-PX)的活性及丙二醛(malondialdehyde，MDA)的含量。结果：珍珠梅水提物显著降低因D-半乳糖所引起的大鼠血清ALT、AST的升高；对血清SOD、GSH-PX活性有明显的升高作用；对MDA含量有降低作用。结论：珍珠梅水提物对D-半乳糖所致大鼠急性肝损伤有防护作用。     

类似人类老年糖尿病大鼠模型之形态学变化

目的 采用D-半乳糖加高脂高糖乳剂及链脲佐菌素(STZ)构建类似老年人糖尿病的大鼠动物模型,观察其胰腺形态学变化.方法 选用健康Wistar雌性大鼠,20只灌胃生理盐水为正常对照组;20只采用腹腔注射D-半乳糖40 d为衰老模型组;另25只则采用腹腔注射D-半乳糖40 d并灌胃高脂高糖乳剂30 d后腹腔注射STZ(体重≤200 g按30 mg/kg,体重＞200 g者按体表面积进行计算),制备衰老糖尿病模型大鼠,筛选空腹血糖≥11.1 mmol/L者为成模鼠,上述各组大鼠再继续灌胃生理盐水10 d后,各组随机取10个样本以免疫组化、光镜和电镜分别观察大鼠胰岛诱导型一氧化氮合酶(iNOS)表达、胰腺细胞凋亡、胰岛形态及胰岛细胞和腺泡细胞超微结构变化.结果 衰老模型组大鼠胰岛iNOS表达量和胰腺细胞凋亡数较正常对照组增加,衰老糖尿病模型组胰岛iNOS表达量和胰腺细胞凋亡数剧增达3倍以上.HE染色显示,衰老模型组胰岛数量、面积仅为正常的50%～70%,衰老糖尿病模型组胰岛数量、面积仅为正常的20%～30%,且岛内中心部细胞(β细胞)消失尤为显著.电镜观察显示,衰老糖尿病模型组大鼠胰腺细胞明显脱颗粒,呈现膜性结构皱缩,核染色质固缩、碎裂等细胞凋亡征象.结论 采用腹腔注射D-半乳糖加高脂高糖乳剂及腹腔注射STZ,胰腺形态组织学证实大鼠在衰老模型基础上胰岛β、D细胞数量进一步下降可引发糖尿病.     

四氯化碳诱导大鼠慢性肝损伤模型方法的探讨

目的研究大鼠慢性肝损伤模型的建立方法。方法以20％和50％四氯化碳植物油溶液给SD大鼠腹腔注射8周,制备大鼠慢性肝损伤模型,观察大鼠饮食、体重和血清ALT、AST水平的变化,采用TUNEL法观察肝细胞凋亡情况,以评价成模效果。结果实验组大鼠饮食量降低,体重增加缓慢。实验组ALT和AST分别为204．1±35．7U／L和307．5±54．1U／L,而对照组分别27．6±3．1U／L和50．5±9．0U／L。实验组动物出现肝细胞变性、凋亡、坏死及再生等病变。大剂量四氯化碳容易弓l起肝纤维化。结论应用20％～50％四氯化碳溶液在1．5ml·kg^-1 bw剂量下腹腔注射可诱导大鼠典型的肝损伤模型,病变稳定,操作简便,可供实验研究应用。     

类似人类老年糖尿病大鼠模型胰腺形态学变化

目的采用D-半乳糖加高脂高糖乳剂及链脲佐菌素(STZ)构建类似老年人糖尿病的大鼠动物模型,观察其胰腺形态学变化。方法选用健康Wistar雌性大鼠,20只灌胃生理盐水为正常对照组;20只采用腹腔注射D-半乳糖40d为衰老模型组;另25只则采用腹腔注射D-半乳糖40d并灌胃高脂高糖乳剂30d后腹腔注射STZ(体重≤200g按30mg/kg,体重200g者按体表面积进行计算),制备衰老糖尿病模型大鼠,筛选空腹血糖≥11.1mmol/L者为成模鼠,上述各组大鼠再继续灌胃生理盐水10d后,各组随机取10个样本以免疫组化、光镜和电镜分别观察大鼠胰岛诱导型一氧化氮合酶(iNOS)表达、胰腺细胞凋亡、胰岛形态及胰岛细胞和腺泡细胞超微结构变化。结果衰老模型组大鼠胰岛iNOS表达量和胰腺细胞凋亡数较正常对照组增加,衰老糖尿病模型组胰岛iNOS表达量和胰腺细胞凋亡数剧增达3倍以上。HE染色显示,衰老模型组胰岛数量、面积仅为正常的50%～70%,衰老糖尿病模型组胰岛数量、面积仅为正常的20%～30%,且岛内中心部细胞(β细胞)消失尤为显著。电镜观察显示,衰老糖尿病模型组大鼠胰腺细胞明显脱颗粒,呈现膜性结构皱缩,核染色质固缩、碎裂等细胞凋亡征象。结论采用腹腔注射D-半乳糖加高脂高糖乳剂及腹腔注射STZ,胰腺形态组织学证实大鼠在衰老模型基础上胰岛β、D细胞数量进一步下降可引发糖尿病。     

积雪草苷对四氯化碳诱导的大鼠肝纤维化的阻断作用

目的研究积雪草苷对四氯化碳诱导的大鼠实验性肝纤维化的影响。方法将SD大鼠随机分为正常对照组、模型对照组和积雪草苷治疗组,在同一环境中饲养。模型对照组和积雪草苷治疗组采用20％的四氯化碳花生油按每100g体质量0．2mL的剂量腹腔注射4周,制备大鼠肝纤维化模型,正常对照组腹腔注射等量花生油。积雪草苷治疗组于四氯化碳腹腔注射的同时给予含积雪草苷2mg的生理盐水1mL灌胃,1次／d,模型对照组和正常对照组给予等量生理盐水灌胃。第4周实验结束时,取肝组织做病理学观察,取全血做血清球蛋白、白蛋白、谷丙转氨酶、谷草转氨酶和透明质酸含量检测。结果肝组织病理学检查,正常对照组无明显病理改变,积雪草苷治疗组较模型对照组的肝纤维化分级显著降低（P〈0．05）;积雪草苷治疗组的血清谷丙转氨酶、谷草转氨酶和透明质酸平均升高水平也较模型对照组有显著降低（P〈0．01）,两组血清球蛋白和白蛋白水平无显著差异。结论积雪草苷对四氯化碳诱导的大鼠肝纤维化有明屁的阻断作用。     

硫化氢对D-半乳糖所致大鼠心肌组织氧化应激和细胞凋亡的影响

目的观察硫化氢对D-半乳糖所致大鼠心肌组织氧化应激及细胞凋亡的影响。方法雄性SD大鼠40只,随机分为对照组、D-半乳糖组、硫化氢6.25μmol/kg组(H2S-1),硫化氢12.5μmol/kg(H2S-2)组,每组10只。D-半乳糖组每日腹腔注射D-半乳糖400 mg.kg-1.d-1,连续60 d;对照组每日腹腔注射等体积生理盐水;硫化氢组处理同D-半乳糖组,同时分别按6.25和12.5μmol/kg腹腔注射硫化氢。采用黄嘌呤氧化酶法和硫代巴比妥酸(TBA)法检测心肌组织超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量;采用Western印迹检测Bcl-2和Bax蛋白表达水平并测定组织Caspase-3相对活性。结果与对照组相比,D-半乳糖组大鼠心肌组织SOD活性下降、MDA含量升高,Bcl-2蛋白表达下调、Bax蛋白表达上调,Caspase-3相对活性升高;给予硫化氢能显著改善D-半乳糖所致大鼠心肌组织氧化应激水平,减少细胞凋亡。结论硫化氢可通过提高抗氧化能力和减少细胞凋亡缓解D-半乳糖所致心肌组织损伤。     

人血白蛋白及D-氨基半乳糖、脂多糖联合诱导建立大鼠慢加急性肝衰竭模型

目的建立与人慢加急性肝衰竭病理过程、生化改变相似,实用性、重复性好的动物模型,为研究慢加急性肝衰竭发生的病理生理机制、药物筛选及疗效评价提供适宜的模型。方法用人血清白蛋白免疫诱导建立肝纤维化大鼠模型,至肝纤维化达S4时予以D-氨基半乳糖与脂多糖联合攻击,计算动物病死率及生存时间,动态观察给药后4、8、12h肝功能、血浆细胞因子水平及病理变化,并以TUNEL法检测原位细胞凋亡,计算凋亡指数。结果人血白蛋白攻击6周时绝大多数大鼠形成经典肝硬化或重度肝纤维化。D-氨基半乳糖与脂多糖联合同时腹腔注射后90%大鼠死于肝衰竭,平均生存时间（16.1±3.7）h,病理表现为肝硬化再生结节内发生大块或亚大块坏死,纤维间隔保留。转氨酶及胆红素的变化符合肝细胞大片坏死时的功能改变,血清TNFα明显增高并与凋亡程度相一致。IL-10随给药时间延长而增高,与临床慢加急性肝衰竭患者变化相似。结论对人血白蛋白免疫诱导型肝硬化及肝纤维化大鼠给予D-氨基半乳糖/脂多糖联合急性攻击可建立慢加急性肝衰竭模型,本实验模拟了临床经常遇到的慢性肝病基础之上发生急性肝衰竭的部分病理生理过程。TNFα介导的肝细胞凋亡可能是该慢加急性肝衰竭重要病理机制之一。     

Effect of naked eukaryotic expression plasmid encoding rat augmenter of liver regeneration on acute hepatic injury and hepatic failure in rats

AIM: To study the protective effect of eukaryotic expression plasmid encoding augmenter of liver regeneration (ALR) on acute hepatic injury and hepatic failure in rats. METHODS: The PCR-amplified ALR gene was recombined with pcDNA3 plasmid, and used to treat rats with acute hepatic injury. The rats with acute hepatic injury induced by intraperitoneal injection of 2 mL/kg 50% carbon tetrachloride (CCl4) were randomly divided into saline control group and recombinant pcDNA3-ALR plasmid treatment groups. Recombinant pcDNA3-ALR plasmid DNA (50 or 200 μg/kg) was injected into the rats with acute hepatic injury intraven ously, intraperitoneally, or intravenously and intraperitoneally in combination 4 h after CCl4 administration, respectively. The recombinant plasmid was injected once per 12 h into all treatment groups four times, and the rats were decapitated 12 h after the last injection. Hepatic histopathological alterations were observed after HE staining, the expression of proliferating cell nuclear antigen (PCNA) in liver tissue was detected by immunohistochemical staining, and the level of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was determined by biochemical method. The recombinant plasmid DNA (200 μg/kg) and saline were intraperitoneally injected into the rats with acute hepatic failure induced by intraperitoneal injection of 4 mL/kg 50% CCl4 after 4 h of CCl4 administration, respectively. Rats living over 96 h were considered as survivals. RESULTS: The sequence of ALR cDNA of recombinant pcDNA3-ALR plasmid was accordant with the reported sequence of rat ALR cDNA. After the rats with acute hepatic injury were treated with recombinant pcDNA3-ALR plasmid, the degree of liver histopathological injury markedly decreased. The pathologic liver tissues, in which hepatic degeneration and necrosis of a small amount of hepatocytes and a large amount of infiltrating inflammatory cells were observed, and they became basically normal in the most effective group after four times of injection of recombinant pcDNA3-ALR plasmid. The indexes of PCNA significantly increased in the recombinant pcDNA3-ALR plasmid treatment groups compared to model group. The level of serum AST and ALT remarkably reduced in recombinant pcDNA3-ALR plasmid treatment groups compared to model group. The results showed that the effect of 200 μg/kg recombinant pcDNA3-ALR plasmid in the rats with acute liver injury was stronger than that of 50 μg/kg pcDNA3-ALR DNA. The effect of intravenous injection of recombinant pcDNA3 ALR plasmid was better. After the rats with acute hepatic failure were treated with recombinant pcDNA3-ALR plasmid, the survival rate (40%) significantly increased in treatment groups compared to control group (15%, P<0.01). CONCLUSION: The ALR gene may play an important role in relieving acute hepatic injury and hepatic failure by promoting hepatic cell proliferation and reducing level of AST and ALT in CCl4-intoxicated rats.     

选择性环氧合酶-2抑制剂塞莱希布对大鼠肝纤维化的作用

目的:探讨选择性COX-2抑制剂塞莱昔布对CCl4诱导的大鼠肝纤维化的作用.方法:5-6周龄的♂SD大鼠50只,随机分为6组.A组(肝纤维化模型组):10只,50%CCl4橄榄油溶液1mL/kg,每周2次皮下注射,同时给予生理盐水灌胃;B组(早期治疗组):10只,造模同时给予塞莱昔布15mg/kg溶于生理盐水中灌胃,每天1次;C组(中期治疗组):10只,造模同时给予生理盐水灌胃,第3周起改为塞莱昔布灌胃;D组(晚期治疗组):10只,造模同时给予生理盐水灌胃,第5周起改为塞莱昔布灌胃;E组:5只,给予相同体积的橄榄油皮下注射,同时给予相同剂量的塞莱昔布灌胃;F组:5只,给予相同体积的橄榄油皮下注射和生理盐水中灌胃.上述处置共8wk.实验结束后腹主动脉取血,取肝组织,检测血清谷丙转氨酶(ALT)、透明质酸(HA)、层粘连蛋白(LN)水平;病理组织学HE染色及Masson染色观察肝纤维化严重程度并评分,免疫组织化学方法检测肝组织Ⅰ胶原、α-SMA、COX-1、COX-2的表达.结果:A组与F组相比,可见显著的肝纤维化改变(P<0.01);与A组相比,B组病理染色可见肝纤维化程度明显减轻(P<0.01),血清ALT、...     

Therapeutic effect of melatonin on carbon tetrachloride-induced acute liver injury in rats

The therapeutic effect of melatonin on acute liver injury was examined in rats intoxicated with carbon tetrachloride (CCl4). Melatonin (10, 50, or 100 mg/kg body weight [BW]) was intraperitoneally administered to male Wistar rats 6 hr after intraperitoneal injection of CCl4 (1.6 g/kg BW) at which time an apparent liver injury occurred. This post-melatonin administration dose dependently prevented the progression of liver injury at 24 hr after CCl4 injection, judging from the levels of serum transaminases, indices of liver cell damage. Rats injected with CCl4 alone showed an increase in liver lipid peroxide (LPO) content and a decrease in liver reduced glutathione content at 6 and 24 hr after the injection. The post-melatonin administration dose dependently ameliorated both changes found at 24 hr after CCl4 injection. Rats injected with CCl4 alone showed an increase in liver triglyceride (TG) content and decreases in serum TG concentration and liver tryptophan 2,3-dioxygenase (TDO) activity, a marker of the inhibition of liver protein synthesis by CCl4, at 6 and 24 hr after the injection, and also a decrease in serum albumin concentration at 24 hr. The changes in serum TG, albumin concentration, liver TG content, and TDO activity found at 24 hr after CCl4 injection were not ameliorated by the post-administration of melatonin. The same administration of melatonin dose dependently reduced liver LPO content in CCl4-untreated rats. These results indicate that melatonin exerts a therapeutic effect on CCl4-induced acute liver injury in rats, possibly through its antioxidant action.     

Hemodynamic and hepatic microcirculational changes in endotoxemic rats treated with different NOS inhibitors

BACKGROUND/AIMS: Severe septic shock may produce hypotension, which is due to the vasodilatational effect of nitric oxide. The effects of different nitric oxide synthase inhibitors on the hemodynamic and hepatic microcirculation of the endotoxemic rats were studied. METHODOLOGY: A prospective controlled study was performed. Eighteen Sprague-Dawley male rats (250-300 g) were anesthetized and studied. The rats were divided into three groups. The rats in group A (n = 6) were injected with lipopolysaccharide (50 mg/kg BW) and L-NAME (5 mg/kg BW). The rats in group B (n = 6) were injected with the same dose of lipopolysaccharide and aminoguanidine (400 mumole/kg BW). The rats in group C rats (n = 6) were injected with same dose of lipopolysaccharide and normal saline as a control. The rats were cannulated with femoral arterial, venous, and jugular venous catheters. Cardiac output was measured using a thermodilutional method, and liver sinusoidal microcirculation was measured with Laser Doppler Flowmetry. The cardiac output, stroke volume, heart rate, blood pressure, and microcirculational flux of the liver in the three groups were measured and compared at 0, 20, 40, 60 and 80 minutes after injection. RESULTS: The rats of group A showed significant decrease of their cardiac output, stroke volume and hepatic microcirculation after the drugs were infused though their blood pressure increased. The rats of group B showed decrease of their blood pressure and stroke volume initially, but no significant change of their cardiac output and hepatic microcirculation. At the 80th min, the rats of group B had the significantly highest cardiac output, stroke volume and hepatic microcirculation among three groups. CONCLUSIONS: The aminoguanidine prevents the hypotensive effect as well as L-NAME during severe sepsis, but it can maintain cardiac output, stroke volume and hepatic microcirculation better than L-NAME.     

乌司他丁对Wistar大鼠暴发性肝衰竭的治疗作用

目的 研究乌司他丁（Ulinastatin,UTI）对大鼠暴发性肝衰竭（fuhninant hepatic failure,FHF）的治疗作用,探讨其作用机制。方法72只Wistar大鼠,随机分为3组：正常组、模型组、治疗组;模型组和治疗组用D-氨基半乳糖（D—GaIN）、脂多糖（LPS）构建大鼠肝衰竭模型,正常组注射等量生理盐水,模型制作成功后治疗组腹腔注射乌司他丁2×10^5U／kg,其他两组注射等量生理盐水。于造模后6、12、24、48h各组分别随机处死6只大鼠,检测血生化指标AST、ALT等,观察肝脏病理变化,测定肝脏髓过氧化物酶（Myelo—peroxidase,MPO）活性,检测血液中TNF—α、IL-1β、IL-6、NO水平。结果与模型组比较,治疗组的存活率升高、生化指标明显好转;病理切片显示,肝脏损伤情况减轻;肝脏MPO活性降低;同时,血清TNF-α、IL-1β、IL-6、NO水平明显降低。结论乌司他丁对大鼠暴发性肝衰竭模型有确切治疗作用,表现为TNF—α等促炎因子的分泌减少,NO炎症损伤减少及炎性细胞浸润降低。     

Melatonin ameliorates experimental hepatic fibrosis induced by carbon tetrachloride in rats

AIM： To investigate the protective effects of melatonin on carbon tetrachloride （CCl4）-induced hepatic fibrosis in experimental rats.
METHODS： All rats were randomly divided into normal control group, model control group treated with CCl4 for 12 wk, CCl4 ＋ NAC group treated with CCl4 ＋ NAC （100 mg/kg, i.p.） for 12 wk, CCl4 ＋ MEL-1 group treated with CCl4 ＋ melatonin （2.5 mg/kg） for 12 wk, CCl4 ＋ MEL-2 group treated with CCl4 ＋ melatonin （5.0 mg/kg） for 12 wk, and CCl4 ＋ MEL-3 group treated with CCl4 ＋ melatonin （10 mg/kg）. Rats in the treatment groups were injected subcutaneously with sterile CCl4 （3 mL/kg, body weight） in a ratio of 2：3 with olive oil twice a week. Rats in normal control group received hypodermic injection of olive oil at the same dose and frequency as those in treatment groups. At the end of experiment, rats in each group were anesthetized and sacrificed. Hematoxylin and eosin （HE） staining and Van Gieson staining were used to examine changes in liver pathology. Serum activities of alanine aminotransferase （ALT）, aspartate aminotransferase （AST） and protein concentration weremeasured with routine laboratory methods using an autoanalyzer. Hydroxyproline （HYP） content in liver and malondialdehyde （MDA） and glutathione peroxidase （GPx） levels in liver homogenates were assayed by spectrophotometry. Serum hyaluronic acid （HA）, laminin （LN）, and procollagen Ⅲ N-terminal peptide （PⅢNP） were determined by radioimmunoassay.
RESULTS： Pathologic grading showed that the fibrogenesis was much less severe in CCl4 ＋ MEL3 group than in model control group （u = 2.172, P 〈 0.05）, indicating that melatonin （10 mg/kg） can significantly ameliorate CCl4-induced hepatic fibrotic changes. The serum levels of ALT and AST were markedly lower in CCl4 ＋ MEL treatment groups （5, 10 mg/kg） than in model control group （ALT： 286.23 ± 121.91 U/L vs 201.15 ± 101.16 U/L and 178.67 ± 103.14 U/L, P = 0.028, P = 0.007; AST： 431.00 ± 166.35 U/L vs 321.23 ± 162.48 U/L and 292.42 ± 126.23 U/L, P = 0.043, P = 0.013）. Similarly, the serum laminin （LN） and hyaluronic acid （HA） levels and hydroxyproline （HYP） contents in liver were significantly lower in CCl4 ＋ MEL-3 group （10 mg/kg） than in model control group （LN： 45.89 ± 11.71 μg/L vs 55.26 ± 12.30 μg/L, P = 0.012; HA： 135.71±76.03 μg/L vs 201.10 ± 68.46 μg/L, P = 0.020; HYP： 0.42 ± 0.08 mg/g tissue vs 0.51 ± 0.07 mg/g tissue, P = 0.012）. Moreover, treatment with melatonin （5, 10 mg/kg） significantly reduced the MDA content and increased the GPx activity in liver homogenates compared with model control group （MDA： 7.89 ± 1.49 noml/mg prot vs 6.29 ±1.42 noml/mg prot and 6.25 ±2.27 noml/mg prot, respectively, P = 0.015, P = 0.015; GPx： 49.13 ±8.72 U/mg prot vs 57.38 ±7.65 U/mg prot and 61.39 ±13.15 U/mg prot, respectively, P = 0.035, P = 0.003）.
CONCLUSION： Melatonin can ameliorate CCl4 -induced hepatic fibrosis in rats. The protective effect of melatonin on hepatic fibrosis may be related to its antioxidant activities,     

Antithrombin III injection via the portal vein suppresses liver damage

AIM: To investigate the effects of antithrombin III (AT III) injection via the portal vein in acute liver failure.METHODS: Thirty rats were intraperitoneally challenged with lipopolysaccharide (LPS) and D-galactosamine (GalN) and divided into three groups: a control group; a group injected with AT III via the tail vein; and a group injected with AT III via the portal vein. AT III (50 U/kg body weight) was administrated 1 h after challenge with LPS and GalN. Serum levels of inflammatory cytokines and fibrin degradation products, hepatic fibrin deposition, and hepatic mRNA expression of hypoxia-related genes were analyzed.RESULTS: Serum levels of alanine aminotransferase, tumor necrosis factor-α and interleukin-6 decreased significantly following portal vein AT III injection compared with tail vein injection, and control rats. Portal vein AT III injection reduced liver cell destruction and decreased hepatic fibrin deposition. This treatment also significantly reduced hepatic mRNA expression of lactate dehydrogenase and heme oxygenase-1.CONCLUSION: A clinically acceptable dose of AT III injection into the portal vein suppressed liver damage, probably through its enhanced anticoagulant and anti-inflammatory activities.     

急性肝功能衰竭大鼠内毒素血症对肝脏和肾脏糖异生功能的影响

目的探讨大鼠急性肝功能衰竭时内毒素血症对肝脏及肾脏糖异生功能及血糖水平的影响。方法24只雄性健康成年SD大鼠,随机分成4组,每组6只,Ⅰ组：腹腔注射等渗盐水,Ⅱ组：腹腔注射400 mg/kg D-氨基半乳糖（D-GaLN）;Ⅲ组：腹腔注射400 mg/kg D- GaLN＋50μg/kg LPS,Ⅳ组：腹腔注射400 mg/kg D-GaLN＋500μg/kg LPS。LPS注射后6 h,取血清检测内毒素、肾功能,取大鼠肝组织及肾组织,采用荧光定量PCR方法检测磷酸烯醇丙酮酸磷酸羧激酶（PEPCK）基因表达。结果Ⅰ组、Ⅱ组大鼠未见明显的内毒素血症,Ⅲ组、Ⅳ组大鼠体内内毒素水平明显升高,Ⅳ组高于Ⅲ组（8.05±0.43对比3.50±2.25,P〈0.05）。Ⅰ组、Ⅱ组、Ⅲ组大鼠于LPS注射前后未出现低血糖,Ⅳ组大鼠于LPS注射后6h出现明显的低血糖。各组大鼠肾功能均在正常水平,仅有Ⅳ组大鼠出现血清尿素氮水平轻度增高。大鼠肝脏PEPCK的表达在Ⅰ组、Ⅱ组、Ⅲ组、Ⅳ组逐渐减少,差异有统计学意义（2.54±1.32、1.87±0.15、0.91±0.13、0.44±0.42,P〈0.05）;大鼠肾脏PEPCK的表达,同Ⅰ组比较,Ⅱ组无明显变化（0.75±0.03对比0.77±0.04,P〉0.05）,Ⅲ组明显增强（0.75±0.03对比1.63±0.86,P〈0.05）,Ⅳ组大鼠肾脏PEPCK表达显著减弱（0.75±0.03对比0.13±0.07,P〈0.05）。结论急性肝功能衰竭大鼠中严重的内毒素血症通过抑制PEPCK的转录损伤肝脏和肾脏糖异生的功能,导致低血糖的发生。     

Therapeutic value of melatonin in an experimental model of liver injury and regeneration

Melatonin has marked antioxidant properties. The aim of the present study was to evaluate the therapeutic effect of melatonin on acute liver injury induced in rats by carbon tetrachloride (CCl4), allyl alcohol (AA) and their combination. A total of 108 male Wistar rats were divided into 12 experimental groups according to their treatment regimen (n = 5-10 rats in each group). Melatonin (100 mg/kg body weight, BW) was administered 6 hr (a) after a single dose of CCl4 (intragastrically 0. 66 mL/kg BW diluted 1:1 v/v with corn oil); (b) a single dose of AA (intraperitonealy, 0.62 mmol/kg BW 1:50 v/v in 0.9% saline solution); and (c) a combination of the above substances. Rats were sacrificed at 24 and 48 hr post-toxin administration and the therapeutic effect of melatonin was investigated by assessment of histopathological changes and lipid peroxidation alterations determined by measuring tissue malondialdehyde plus 4-hydroxy-nonenal (MDA + 4-HNE), plasma MDA and plasma levels of liver enzymes. The levels of a key antioxidant, glutathione (GSH), were measured in liver tissue homogenates. Hepatic necrosis was significantly reduced in the melatonin-treated rats 48 hr after administration of CCl4, AA and CCl4 + AA. The levels of hepatic enzymes in plasma were found to be significantly reduced at 24 and 48 hr in the CCl4 + AA treated rats after melatonin administration. Additionally, MDA and MDA + 4-HNE concentrations were significantly reduced at 24 and 48 hr time-points in all groups that received melatonin. GSH levels were decreased in liver after the toxic substances administration, whereas melatonin reversed this effect. In conclusion, a single dose of melatonin decreased hepatic injury induced by CCl4, AA and CCl4 + AA. The inhibition of the oxidative stress and therefore lipid peroxidation by melatonin in CCl4 and AA administered animals, may constitute the protective mechanism of melatonin against acute liver injury.