c-Myc抑制剂10058-F4减轻脂多糖/右旋半乳糖胺诱导的小鼠急性肝损伤

本研究探讨c-Myc抑制剂10058-F4对脂多糖(lipopolysaccharide, LPS)和右旋半乳糖胺(D-galactosamine, D-Gal)诱导的急性肝损伤的影响及其可能机制。32只雄性BALB/c小鼠(Mus musculus)分为4组：正常对照组、 10058-F4组、 LPS/D-Gal组和10058-F4+LPS/D-Gal组。通过腹腔注射LPS/D-Gal诱导小鼠急性肝损伤,10058-F4在注射LPS/D-Gal前0.5 h经腹腔注入。注射LPS/D-Gal 1.5 h后处死小鼠并采集样本,分别采用实时荧光定量PCR法和ELISA法检测肝组织中肿瘤坏死因子-α(tumor necrosis factor-α, TNF-α)的mRNA水平和血清中TNF-α的水平。另取32只小鼠经上述相同处理后,注射LPS/D-Gal 6 h后处死并采集样本,检测小鼠血清中转氨酶活性及白介素-6(interleukin-6, IL-6)的水平、肝组织中IL-6的mRNA水平及肝组织中半胱氨酸天冬氨酸特异性蛋白酶(cysteinyl aspartate specific p...     

大鼠再生肝抗CCl4损伤与其线粒体呼吸活性变化的关系

本工作观察了肝部分切除(68%)后96h 大鼠再生肝的抗 CCl_4损伤作用,并用氧电极法测定了再生肝线粒体的呼吸活性。结果如下: (1)CCl_4(50%,10ml/kg)引起的动物死亡率,肝切除组大鼠较假手术组明显降低;(2)CCl_4(50%,5 ml/kg)损伤后,肝切除组大鼠血清胆红素、血清谷丙转氨酶(sGPT)均明显低于假手术组,组织学检查损伤程度也明显减轻;(3)无论是否伴有 CCI_1损伤,肝切除组大鼠肝线粒体的呼吸活性均强于假手术组,且肝线粒体呼吸活性的变化与血清胆红素、sGPT 及肝组织损伤程度的改善是一致的。上述结果提示:再生肝线粒体呼吸活性增高,同时不易受 CCl_4损伤,可能在再生肝抗 CCl_4损伤机制中起一定作用。     

PH797804对小鼠急性肝衰竭的保护作用及机制研究

目的:研究PH797804对脂多糖/D-氨基半乳糖氨(Lipopolysaccharide/D-galactosamine, LPS/D-Gal)诱导的急性肝衰竭(Acute liver failure, ALF)小鼠的保护作用及机制。方法:将64只小鼠随机分成四组,每组16只。腹腔注射LPS/D-Gal诱导建立小鼠ALF模型,设立生理盐水对照组(a)、LPS/D-Gal诱导模型组(b)、LPS/D-Gal诱导和PH797804干预组(c)及PH797804处理对照组(d)。观察小鼠48 h内的存活率,检测血清中谷丙转氨酶(ALT)和谷草转氨酶(AST)的含量,HE染色组织切片观察肝脏病理变化,Elisa检测血清中TNF-α和IL-6的表达水平,并对各组小鼠肝组织进行高通量转录组测序以探寻作用机制,采用Real-time PCR法验证测序结果。结果:相比于ALF模型组小鼠,PH797804处理后c组小鼠48 h存活率从20%提高至80%,小鼠肝脏组织病理学异常显著改善,血清中ALT、AST含量较ALF模型组相比显著降低(P0.01),血清中TNF-α和IL-6等促炎细胞因子含量较ALF模型组相比显著降低(P0.01)。RNA测序结果提示PH797804对LPS/D-Gal诱导小鼠ALF的保护作用主要与抑制炎症反应相关。Real-time PCR验证了测序结果的可靠性。结论:PH797804对LPS/D-Gal诱导的小鼠ALF具有保护作用,其作用机制可能与抑制炎症反应有关。     

髓过氧化物酶与大剂量顺铂所致小鼠肝功能变化关系的探讨

目的利用大剂量顺铂（Cisplatin,DDP）诱发小鼠急性肾功能衰竭的动物模型,了解大剂量DDP在引起肾损伤的同时对小鼠肝的毒性作用,探讨髓过氧化物酶（Peroxidase,MPO）与DDP所致小鼠肝功能变化的关系。方法 C57BL/6小鼠50只,雌雄各半,依体重随机分为DDP用药组和生理盐水（NS）对照组。15 mg/kg DDP单次腹腔内注射,等量NS对照。分别取对照组小鼠和DDP用药后6、12、24和48 h小鼠各10只,称重后乙醚麻醉,内眦静脉取血检测肝、肾功能;剖腹取肝、称重、计算肝系数,并取少量肝组织行HE染色、形态学观察;检测血浆和肝组织匀浆中MPO活性,统计学分析。结果大剂量DDP用药后48 h,小鼠出现急性肾功能衰竭。DDP用药后6 h血清谷丙转氨酶（ALT）含量达（91.0±11.3）IU/L,与对照组比较差异有统计学意义（P〈0.05）,随后血清ALT含量持续维持在高水平。DDP用药后各组小鼠肝系数明显升高,光镜下见肝细胞广泛变性水肿,肝小叶中可见点状坏死及炎细胞浸润。DDP用药后6 h,小鼠肝组织匀浆MPO含量显著升高,达（1.54±0.45）U/g,与对照组（0.58±0.28）U/g差异有统计学意义（P〈0.01）,随后MPO含量降至正常水平;DDP用药后小鼠外周血MPO含量缓慢增高,用药后48 h达（12.78±2.78）U/L,与对照组（8.06±1.89）U/L比较差异有统计学意义（P〈0.05）。结论大剂量DDP在诱发小鼠急性肾功能衰竭的同时还可引起小鼠急性肝细胞的破坏,其发生可能与肝组织内白细胞的激活及MPO的释放有关。     

正丁酸钠通过抑制高迁移率族蛋白B1的表达与释放减轻刀豆蛋白A诱导的小鼠急性肝损伤

本文旨在研究正丁酸钠预处理对刀豆蛋白A(concanavalin A,Con A)诱导的小鼠急性肝损伤的保护作用及机制。给小鼠腹腔注射正丁酸钠(500 mg/kg)0.5 h后,尾静脉注射Con A(15 mg/kg)诱导小鼠急性肝损伤模型,测定小鼠血清谷丙转氨酶(alanine aminotransferase,ALT)、谷草转氨酶(aspartate aminotransferase,AST)的水平;HE染色观察病理学改变;ELISA法检测血清肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、干扰素-γ(interferon-γ,IFN-γ)和高迁移率族蛋白B1(high-mobility group box 1,HMGB1)水平;RT-PCR和免疫组化法检测小鼠肝组织HMBG1的表达与释放。结果显示,正丁酸钠预处理能明显降低Con A诱导的急性肝损伤小鼠血清中ALT和AST水平(P0.01);显著改善肝组织损伤程度;明显降低血清中TNF-α和IFN-γ的水平(P0.01);显著抑制肝组织HMGB1的表达与释放(P0.05或P0.01)。以上结果提示,正丁酸钠预处理对Con A所诱导的小鼠急性肝损伤具有保护作用,可能与其减少炎性细胞因子TNF-α和IFN-γ的产生及抑制HMGB1的表达与释放有关。     

Drp1抑制剂Mdivi-1对脂多糖/D-半乳糖胺诱导的急性肝损伤的影响及机制研究

线粒体动力相关蛋白1(dynamin-related protein 1,Drp1)是细胞凋亡调控的新靶点,而凋亡是急性肝损伤的重要特征,该研究采用选择性Drp1抑制剂Mdivi-1,探讨了Drp1在急性肝损伤中的可能病理生理学作用及其潜在的药靶价值。该研究动物实验采用6～8周龄雄性BAlB/c小鼠,在腹腔内注射脂多糖(lipopolysaccharide,LPS)/D-半乳糖胺(D-galactosamine,D-Gal),诱导急性肝损伤模型。实验分为四组:正常对照组(A)、Mdivi-1单独处理组(B)、模型组(C)和Mdivi-1干预组(D)。Mdivi-1在LPS/D-Gal暴露前30 min经腹腔注入,在LPS/D-Gal注射后1.5 h或6.0 h处死动物,采集肝组织和血浆标本。实验通过组织病理学染色、比色法检测血浆转氨酶活性、细胞因子TNF-α检测、casepase-3、casepase-8和casepase-9的活性检测和TUNEL技术探讨Mdivi-1介导下肝损伤的改善情况。结果显示,通过HE染色观察肝组织病理学改变,正常对照组和Mdivi-1单独处理组小鼠肝组织结构无异常,LPS/D-Gal暴露后可引起一系列显著的组织学异常改变,Mdivi-1干预组肝组织学异常明显减轻。通过检测血浆谷丙转氨酶(alanine aminotransferase,ALT)、谷草转氨酶(aspartate aminotransferase,AST)活性评估肝脏功能损害程度,Mdivi-1干预组ALT和AST的活性明显降低(P0.05)。采用ELISA法检测血浆中肿瘤坏死因子α(tumor necrosis factor alpha,TNF-α)水平以评估炎症反应程度,Mdivi-1干预组的炎性细胞因子表达降低明显(P0.05)。通过半胱氨酸蛋白酶-3(casepase-3)、半胱氨酸蛋白酶-8(casepase-8)、半胱氨酸蛋白酶-9(casepase-9)和TUNEL染色评估组织凋亡程度,Mdivi-1干预组的凋亡水平降低显著(P0.05)。所以得出结论,Mdivi-1干预可减轻 LPS/D-Gal诱导的肝组织病变、降低血浆转氨酶、下调血浆中 TNF-α水平、降低肝内casepase-3、casepase-8和casepase-9活性并减少TUNEL阳性细胞的数量。以上数据表明,Drp1抑制剂Mdivi-1可减轻LPS/D-Gal诱导的急性肝损伤。     

小鼠肝纤维化中内质网应激分子的表达与作用

[目的]利用高脂饲料和异种血清诱导建立肝纤维化模型,检测内质网应激分子在该纤维化模型中的作用及机制。[方法]收集各组小鼠血清进行ALT检测,对小鼠肝组织进行HE和Masson染色观察肝组织的结构变化以及胶原纤维状况,并分别用Western和RT-PCR检测组织内CRT、GRP78、TLR2等基因的表达。[结果]与正常对照组(48.8±6.1 U/L)相比高脂饲料饮食组(139.7±13.4 U/L)、腹腔注射异种血清组(72.8±7.2U/L)以及高脂饲料联合腹腔异种血清注射组(193.0±14.1 U/L)血清ALT显著升高(p0.05);镜下也观察到肝细胞脂肪变性,大量的胶原纤维产生;肝组织内GRP78和TLR2基因mRNA水平、CRT蛋白水平均升高(p0.05)。[结论]高脂饲料和异种血清诱导建立的肝纤维化模型显示内质网应激与肝纤维化的发生发展密切相关。     

人肝刺激因子对CCl4损伤大鼠离体肝细胞内钙和钾离子稳态的影响

本工作从自愿流产孕妇的胎儿取肝,按照LaBrecque法提取人肝刺激因子(human hepaticstimulator substance,hHSS)。用荧光探针Fura-2/AM测定离体肝细胞内游离钙,用离子分析仪测细胞染毒(四氯化碳CCl_4)前后基质中钾离子含量,观察hHSS对染毒肝细胞内Ca~(2+)和K~+稳态的影响,并测定肝细胞存活率和细胞内转氨酶(ALT)的漏出作为佐证。结果表明,人胎肝中含有hHSS,hHSS能提高离体肝细胞的存活率,维持肝细胞内游离钙的相对恒定,减少细胞内钾离子和ALT的漏出。这些结果提示,hHSS可保护肝细胞内钙,钾离子稳态和肝细胞膜的稳定,从而加强大鼠离体肝细胞抗CCl_4的损伤。     

黄芪多糖与枸杞多糖联用对小鼠肝组织损伤的保护作用

探究黄芪多糖与枸杞多糖对四氯化碳(CCl_4)所致小鼠急性肝损伤的协同保护作用。采用CCl_4诱导小鼠急性肝损伤,动物处死后取血液测定血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)活性,取肝脏计算肝指数并制备肝匀浆测定其中谷胱甘肽(GSH)活力、丙二醛(MDA)含量,并对小鼠肝脏进行组织切片观察,评价黄芪多糖与枸杞多糖联用对小鼠肝组织的保护效果。实验显示,黄芪多糖与枸杞多糖各配比(LBP 50 mg/kg+APS 100,LBP 70 mg/kg+APS 400,LBP 350 mg/kg+APS 800)均能显著抑制CCl_4急性肝损伤所引起的MDA含量、肝脏指数、ALT和AST活性的升高(p0.05),有效地提高肝脏中GSH的含量,减轻小鼠的肝组织损伤程度。本研究表明黄芪多糖与枸杞多糖联用对CCl_4诱导的小鼠急性肝损伤有明显的保护作用。     

4-羟基苯并恶唑-2-酮对四氯化碳致小鼠急性肝损伤保护作用

日的研究4一羟基苯并恶唑-2-酮（4-hydroxy-2-benzoxazolone,HBOA）对四氯化碳所致小鼠急性肝损伤的保护作用,并探讨其疗效机制。方法采用腹腔注射四氯化碳（carbonte trachloride,cch）制备小鼠急性肝损伤模型,HBOA灌胃给药,检测小鼠血清中的乳酸脱氢酶（LDH）活性以及肝组织中过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）含量,并用免疫组化法观察肿瘤坏死因子（TNF-a）的表达情况。结果HBOA能明显降低CCh致急性肝损伤小鼠血清LDH活性,同时升高肝组织中CAT、GSH-Px的活性并降低肝组织中TNF-a的表达。结论HBOA对CCh所致小鼠急性肝损伤有一定的保护作用。     

肝再生刺激因子对小鼠实验性急性肝损伤的保护作用

本工作采用雄性初断乳 SD 大鼠肝按 LaBrecque 法提取肝再生刺激因子(HSS),用四氯化碳和半乳糖胺分别损伤小鼠肝来研究 HSS 的保肝作用。结果如后:(1)HSS 可使 CCl_4致肝损伤小鼠的血清 GPT 和 GOT 升高幅度降低,并呈量效关系。(2)肝组织切片表明 HSS 可使 CCl_4损伤肝组织的程度减轻。(3)肝组织化学法表明 HSS 可使 CCl_4损害肝细胞线粒体琥珀酸脱氢酶的活性恢复。(4)胰岛素-胰高糖素可降低半乳糖胺所致的小鼠死亡率,减弱对肝组织的损害和刺激肝细胞增殖,这项实验可作为 HSS 具有保肝作用的证据。     

肝再生剌激因子对小鼠实验性急性肝损伤的保护作用

A hepatic stimulator substance (HSS) was extracted from the liver of male weanling SD rats according to the method of LaBrecque. The mice were injected with carbon tetrachloride or D-galactosamine to induce hepatic injuries and the protective effect of HSS on thus induced hepatic damage was investigated. The results were as follows: (1) HSS could suppresses the elevation of sGPT and sGOT induced by carbon tetrachloride intoxication in a dose-dependent manner. (2) Hepatic histological findings indicated that the degree of CCl4 or D-galactosamine-induced hepatic lesions could be lessened by HSS. (3) CCl4-induced reduction of hepatic mitochondrial succinic dehydrogenase activity could be restored by HSS. (4) Insulin-glucagon enhanced the survival of D-galactosamine intoxicated mice and stimulated hepatocyte proliferation, thus showing less pronounced hepatic damage.     

Change in liver and plasma ceramides during D-galactosamine-induced acute hepatic injury by LC-MS/MS

In fulminant hepatic failure, various toxins causing multi-organ failure increase in plasma. As a novel toxin, ceramide, a well-studied lipid mediator of apoptosis, levels were determined by LC-MS/MS in the liver and plasma of D-galactosamine-intoxicated rats. 18 and 24h after intraperitoneal administration of D-galactosamine (1g/kg body weight) to rats, fulminant hepatic failure occurred as evidenced by a severe elevation in plasma GOT and GPT. The liver concentration of minor ceramide components (C18:0, C20:0, C22:1, C22:0, and C24:2) increased significantly compared to that in the control group that was given saline. The plasma concentration of major ceramides (C24:0, C24:1, C16:0, C22:0, C22:1, and C18:0) increased 24h after administration of D-galactosamine and the total ceramide concentration was also increased to 3.6 times that in the control. In conclusion, the increased concentrations of ceramides in plasma during fulminant hepatic failure may be one of important toxins causing damage in other organs including the brain and kidney.     

Maotai Ameliorates Diethylnitrosamine-Initiated Hepatocellular Carcinoma Formation in Mice

Consumption of alcohol is closely related to liver disease, such as hepatic fibrosis or even hepatocellular carcinoma (HCC). However, epidemiological and experimental studies indicated that consumption of Maotai, one of the famous liquors in China, exhibits no significant correlation with hepatic fibrosis or cirrhosis as other beverage sources do. This study detected the relationship of Maotai consumption and HCC development in a diethylnitrosamine (DEN)-initiated HCC animal model. DEN was given to mice at a dose of 100 mg/kg, ip, and 50 mg/kg, ip in the following week. Mice were simultaneously given Maotai or an equal amount of ethanol (53%, 5 ml/kg/day, 5days/week for up to 35weeks). At 3-week and 35- week of the experiment, serum and livers were collected for biochemical and histopathological examination of liver injury and incidence of HCC. Real-time RT-PCR, immunohistochemistry and Western blotting were used to examine the expression of metallothionein-1/2 (MT-1/2), NF-E2-related factor 2 (Nrf2), glutamate-cysteine ligase catalytic subunit (GCLC) and modified subunit (GCLM). We identified tissue damage and dysfunction of liver in ethanol + DEN-treated mice, whereas the extent of injury was reduced in Maotai+ DEN –treated mice. Significant Glypican-3(GPC3) expression and precancerous injury or HCC were seen in approximately 50% of mice with ethanol+ DEN, but barely be seen in Maotai + DEN-treated mice. A higher expression of MT-1/2, Nrf2 and GCLC could be seen in Maotai + DEN-treated mice. Thus, Maotai liquor ameliorates the formation of DEN-induced HCC in mice, and the protection mechanism is possibly related with the activation of anti-oxidation factors, such as MTs, Nrf2 and GCLC.     

Suppressive effect of modified arabinoxylan from rice bran (MGN-3) on D-galactosamine-induced IL-18 expression and hepatitis in rats

We investigated in this study the effect of modified arabinoxylan from rice bran (MGN-3) and its fractions on D-galactosamine (D-GalN)-induced IL-18 expression and hepatitis in rats. Male Wistar rats were pretreated with MGN-3 or fractions of the MGN-3 hydrolysate, or with saline 1 h before administering D-GalN (400 mg/kg B.W.). The serum transaminase activities, IL-18 mRNA expression level in the liver and IL-18 concentration in the serum were determined 24 h after injecting D-GalN. Both the oral and intraperitoneal administration of MGN-3 (20 mg/kg B.W.) alleviated D-GalN-induced hepatic injury under these experimental conditions. The low-molecular-weight fraction (LMW) of MGN-3 showed the strongest protective effect on D-GalN-induced liver injury, its main sugar component being glucose. Moreover, the D-GalN-induced IL-18 expression was significantly reduced by treating with MGN-3 and LMW. The results suggest that MGN-3 and LMW could provide significant protection against D-GalN liver injury, and that IL-18 might be involved in their protective influence.     

Effect of safranal, a constituent of Crocus sativus (saffron), on methyl methanesulfonate (MMS)-induced DNA damage in mouse organs: an alkaline single-cell gel electrophoresis (comet) assay

The influence of safranal, a constituent of Crocus sativus L. stigmas, on methyl methanesulfonate (MMS)-induced DNA damage was examined using alkaline single-cell gel electrophoresis (SCGE), or comet, assay in multiple organs of mice (liver, lung, kidney, and spleen). NMRI mice were divided into five groups, each of which contained five mice. The animals in different groups were received the following chemicals: physiological saline (10 mL/kg, ip), safranal (363.75 mg/kg, ip), MMS (120 mg/kg, ip), safranal (72.75 mg/kg, ip) 45 min prior to MMS administration, and safranal (363.75 mg/kg, ip) 45 min prior to MMS administration. Mice were sacrificed about 3 h after the administration of direct mutagen MMS, safranal, or saline, and the alkaline comet assay was used to evaluate the influence of safranal on DNA damage in different mouse organs. Increase in DNA migration was varied between 9.08 times (for spleen) and 22.12 times (for liver) in nuclei of different organs of MMS-treated mice, as compared with those of saline-treated animals (p < 0.001). In control groups, no significant difference was found in the DNA migration between safranal- and saline-pretreated mice. The MMS-induced DNA migration in safranal-pretreated mice (363.75 mg/kg) was reduced between 4.54-fold (kidney) and 7.31-fold (liver) as compared with those of MMS-treated animals alone (p < 0.001). This suppression of DNA damage by safranal was found to be depended on the dose, and pretreatment with safranal (72.75 mg/kg) only reduced DNA damage by 25.29%, 21.58%, 31.32%, and 25.88% in liver, lung, kidney, and spleen, respectively (p < 0.001 as compared with saline-treated group). The results of the present study showed that safranal clearly repressed the genotoxic potency of MMS, as measured by the comet assay, in different mouse organs, but the mechanism of this protection needs to be more investigated using different in vitro system assays and different experimental designs.     

lipid peroxidation in liver of mice administrated with nickel chloride

The relationship between Ni-induced hepatic lipid peroxidation (LPO) and the concentrations of Ni and trace elements was investigated in male ICR mice. The protective effects of antioxidants were also examined. Hepatic LPO and the concentrations of Ni, Fe, Cu, and Zn in the liver were enhanced after an ip injection of nickel chloride (NiCl₂). Dose-response studies were conducted on male mice with different groups being injected with 50, 85, and 170 μmol Ni/kg. LPO increased significantly in a dose-dependent manner. In time-course studies, mice were administrated NiCl₂ (170 μmol Ni/kg) and killed at intervals of 6, 12, 24, and 48 h after injection. Both LPO and the accumulation of Ni, Fe, Cu, and Zn in the liver showed a significantly positive time-course relationship after NiCl₂ injection. At 1 h and 24 h after a single ip injection of 170 μmol Ni/kg, the mice were given an ip injection of ascorbic acid (vit C), glutathione (GSH), and selenium (Se). Vit C and GSH significantly decreased both the level of hepatic LPO and the concentration of Ni in the liver, but did not decrease the accumulation of Fe, Cu, and Zn. However, LPO in the experimental group of mice was different significantly from that in the control group. In conclusion, the results suggest that Ni-induced hepatic LPO may result from increasing the amounts of Ni, Fe, and Cu, since these elements are involved in the generation of hydroxyl radical by inducing the Fenton reaction, thus instigating the Ni-mediated hepatic LPO. The protective effects of vit C and GSH in hepatic LPO result not only from removing the oxygen reactive species, but also from decreasing the Ni concentration.     

Toxic effects of a new boron containing heterocycle: 4,4,8,8-tetraethyl-3,3a,4,8-tetrahydro 3a,4a,4-diazabora-S-indacene.

LD50 values in mice for 4,4,8,8-tetraethyl-3,3a,4,8-tetrahydro-3a,4a,4-diazabora-S-indacene (Myborin) were determined by the ip, po, and sc routes. The LD50 value for ip was 69.5 mg/kg found by the method of Litchfield and Wilcoxon, with upper and lower confidence limits of 77.8 and 62.1 mg/kg. Oral and sc LD50's were approximated after the method of Deichmann and LeBlanc and were found to be 180 mg/kg (po) and 420 mg/kg (sc). Each of these values has a confidence range of +/- 30%. Myborin induced convulsions, hyperreflexia, and death accompanied by tetany when given by either the ip or oral routes. Moreover, Myborin induced porphyria in animals surviving for 24 hr after these routes of administration and in virtually all animals dosed sc. Death by the sc route is probably a result of acute porphyria. Hepatomegaly and skin photosensitivity were demonstrated to be profound. Boron levels in the livers of mice were determined colorimetrically 24 hr after ip injections of Myborin and in untreated control mice. The quantity of boron found in the experimental group was 15.46 mug/g wet liver as compared to 8.11 mug/g wet liver for controls (P less than 0.01). The difference corresponds to 23% of the injected quantity of boron.