二草清肝汤治疗免疫性肝损伤大鼠的作用机制

60只健康雄性SD大鼠随机分为5组,正常组、模型组、环磷酰胺(CTX)组(12.6 mg/kg)、二草清肝汤小剂量组(3 ml/kg)和二草清肝汤大剂量组(6 ml/kg).检测各组血清ALT、AST和TNF-α、IL-12的变化,流式细胞仪检测肝细胞凋亡,免疫组化法检测肝细胞bax、bcl-2蛋白的表达.发现二草清肝汤大剂量组、小剂量组、CTX组ALT、AST、TNF-α、IL-12、凋亡率、bcl-2、bax阳性表达和bax/bcl-2较模型组降低.认为二草清肝汤对大鼠免疫性肝损伤具有保护作用,降低血清TNF-α、IL-12水平和抑制肝细胞凋亡可能是其作用机制之一.     

二草清肝汤抗大鼠免疫性肝损伤作用机制的研究

目的：观察中药二草清肝汤对大鼠免疫性肝损伤的防护作用并探讨其药理学机削。方法：采用卡介苗（BCG）＋脂多糖（LPS）建立大鼠免疫性肝损伤模型。做肝组织病理切片观察肝组织损伤情况；采用免疫组化法检测肝组织Bax、Bcl-2的表达；ELISA法检测血清IL-12水平。结果：大鼠免疫性肝损伤时。血清IL-12水平显著升高；肝脏Bax表达明显升高，Bcl-2表达显著降低；中药组及西药（环磷酰胺）对照组大鼠Bax的表达及IL-12水平明显低于模型组（P〈0．01），而Bcl-2表达明显高于模型组（P〈0．01）；中药组和西药组大鼠肝组织病理改变较模型组明显减轻。中药组一般情况明显好于西药组。结论：二草清肝汤能降低免疫性肝损伤大鼠的血清IL-12水平，下调肝Bax的表达。上调Bcl-2的表达，对实验性免疫性肝损伤有明显防护作用。     

甘氨酸对内毒素性肝损害保护作用的实验研究

目的探讨甘氨酸(Gly)对内毒素(LPS)性肝损害的保护机制。方法BABL／c小鼠随机分为两组,LPS组经腹腔注射10 mg／kg的LPS,Gly组在注射相同剂量LPS前3 d开始喂饲含5％Gly的饲料。光镜观察组织病理学改变、免疫组织化学法检测Toll样受体4(TLR4)表达水平；酶联免疫吸附法检测血浆肿瘤坏死因子(TNF)α、白细胞介素10(IL-10)浓度及逆转录聚合酶链反应检测肝组织中TNFα、IL-10及TLR4的mRNA表达水平。结果Gly能明显提高小鼠存活率,肝脏病理损害程度减轻；Gly组TNFα水平显著低于LPS组,差异有统计学意义[(1852.80±126.64)pg／ml对(708.83±51.29)pg／ml,P＜0.05]；Gly组IL-10增加且高峰前移,与LPS组比较差异有统计学意义[(418.64±38.86)pg／ml对(344.09±31.70)pg／ml,P＜0.05]；Gly组肝组织中TNFα及TLR4表达也明显减弱,IL-10表达明显增强,与LPS组比较差异均有统计学意义[分别为TNFα：A值1.59±0.14对0.91±0.11；TLR4：A值0.97±0.12对0.53±0.11；IL-10：A值0.62±0.08对1.06±0.15；P值均＜0.05]。结论Gly能明显减轻LPS所致的肝损害,其机制可能与其下调肝脏各种细胞的TLR4表达,同时上调IL-10的水平有关。     

甘氨酸对内毒素性肝损害保护作用的机制

目的:探讨甘氨酸(Gly)对内毒素(LPS)性肝损害的保护机制．方法:BALB／c小鼠随机分为三组,LPS组(n= 50)经腹腔注射10 mg／kg的LPS,Gly组(n=50) 在注射相同剂量LPS前3 d开始喂饲含50 g／L 的Gly的饲料,正常生理盐水对照组(n=50), 经腹腔注射等体积的生理盐水,光镜观察组织病理学改变,免疫组织化学法检测TLR4表达水平:ELISA法检测血浆TNF-α,IL-10浓度及 RT-PCR检测肝组织中TNF-α,IL-10及TLR4的 mRNA表达水平．结果:Gly能明显提高小鼠存活率,肝脏病理损害程度减轻:Gly组TNF-α水平显著低于LPS 组,差异有统计学意义(708．83±51．29 ng／L vs 1852．8±126．64 ng／L,F=786．21,P<0．05);Gly 组IL-10N加且高峰前移,与LPS组比较差异有统计学意义(418．64±38．86 ng／L vs 211．15 ±26．44 ng／L,P<0．05);Gly组肝组织中TNF-α及TLR4表达也明显减弱,IL-10表达明显增强, 与LPS组比较差异均有统计学意义(分别为 TNF-α A值:1．59±0．14 vs 0．91±0．11;TLR4 A值:0．97±0．12 vs 0．53±0．11;IL-10A值:0．62 ±0．08 vs 1．06±0．15;P均<0．05)．结论:Gly能明显减轻LPS所致的肝损害,其机制可能与其下调肝细胞的TLR4表达,同时上调IL-10的水平有关．     

Toll样受体4在CCI4诱导的大鼠慢性肝损伤过程中的表达

背景：Toll样受体4（TLR4）在内毒素的信号转导过程中具有重要作用。目的：动态观察在CCl4诱导的大鼠慢性肝损伤过程中。肝组织和Kupffer细胞TLR4基因表达的变化，探讨TLR4在肝损伤中的作用。方法：以CCl4诱导慢性肝损伤纤维化大鼠模型，分离肝Kupffer细胞。以逆转录聚合酶链反应（RT-PCR）检测肝组织和Kupffer细胞TLR4 mRNA的表达；将Kupffer细胞分别与不同浓度的脂多糖（LPS）孵育，以酶联免疫吸附测定（ELISA）检测细胞培养上清的肿瘤坏死因子（TNF）-α水平。以基质显色法测定大鼠血浆内毒素水平。结果：正常大鼠肝组织TLR4 mRNA表达水平较低，Kupffer细胞未检测到TLR4 mRNA表达；CCl4处理2～6周大鼠的肝组织和Kupffer细胞TLR4 mRNA表达水平显著增高（P〈0．05）。CCl4处理4周和6周大鼠Kupffer细胞的TNF-α基础分泌水平显著高于正常大鼠（P〈0．05）；在LPS的刺激下，TNF-α的分泌水平较基础值进一步增高（P〈0．05），呈浓度依赖性。大鼠血浆内毒素水平在肝损伤过程中逐渐增高，相关分析显示在慢性肝损伤的早、中期。肝组织和Kupffer细胞TLR4 mRNA的表达与血浆内毒素水平呈正相关。结论：在CCl4诱导的慢性肝损伤过程中，大鼠肝脏TLR4基因表达上调，与Kupffer细胞活化和肝脏的炎症损伤有关。     

模拟代谢性内毒素血症对肝损伤小鼠肝组织TLR4信号通路的影响

目的：观察持续4 w的模拟代谢性内毒素血症对小鼠肝脏组织病理和4型Toll样受体（TLR4）信号通路的影响。方法将30只雄性C57BL/6J 小鼠随机分为正常组（n=10）和内毒素组（n=10）,均予以普通饲料喂养,和高脂组（n=10）,予以高脂饲料喂养。内毒素组小鼠同时经腹部皮下植入的微泵注入内毒素300μg·kg-1·d-1,连续4 w,正常组小鼠皮下微泵持续注入生理盐水作为对照。4 w后测定小鼠血清内毒素水平,对肝组织切片行HE染色后进行非酒精性脂肪性肝病评分（NAS）,采样Real time PCR法测定小鼠肝组织TLR4及其下游的MyD88和TRIF-related adaptor molecule （TRAM） mRNA水平。结果内毒素组小鼠血清内毒素水平（0.62±0.04 EU/ml）显著高于正常组（0.50±0.06 EU/ml,P〈0.05）和高脂组（0.49±0.05 EU/ml,P〈0.05）;内毒素组小鼠肝组织主要表现为单纯性脂肪变性,NAS积分为（2.30±0.49）,高脂组小鼠肝组织炎症较明显,NAS积分为（4.20±1.61）,显著高于内毒素组（P〈0.05）;与正常组相比,内毒素组小鼠肝组织TLR4 mRNA 水平上调5.12倍（P＜0.01）,TRAM mRNA水平上调3.46倍（P＜0.01）,而MyD88 mRNA水平与正常组比,无显著差别。结论持续4 w的模拟代谢性内毒素血症可诱导小鼠肝脏单纯性脂肪变性,TLR4 mRNA 和TRAM mRNA水平上调,而MyD88 mRNA水平无显著变化。     

Toll样受体4在D-氨基半乳糖/内毒素介导的急性肝损伤中的表达

目的研究D-氨基半乳糖(D-Gal)/内毒素介导的急性肝损伤模型中肝组织细胞Toll样受体4(TLR4)的表达变化,探讨TLR4在识别内毒素、启动炎性肝损伤中的作用.方法 BALB/C小鼠腹内注射D-Gal 900 mg/kg与内毒素(即脂多糖,LPS)10 μg/kg后0～7 h分别检测血清丙氨酸转氨酶(ALT)及天门冬氨酸转氨酶(AST)与血浆肿瘤坏死因子(TNF-α)含量以评价肝功能;另随机取10只小鼠给药后观察致死率.用半定量逆转录-聚合酶链反应(RT-PCR)和Tanon Gis 2.0软件分析不同时间点肝组织中TLR4 mRNA表达,并与血浆TNF-α含量进行相关分析;免疫组织化学观察肝组织TLR4蛋白的表达.实验数据用SAS软件分析.结果给药后4 h,血清转氨酶明显升高(与0h比较,P＜0.05);血浆TNF-α含量逐步上升,在2 h、5 h有两个分泌高峰;7 h小鼠开始死亡,10 h致死率达80%.正常小鼠肝组织少量表达TLR4 mRNA,给药后表达明显增强(与0 h比较,P＜0.05);免疫组织化学也显示TLR4蛋白有类似的变化,尤其肝窦内皮细胞、库普弗细胞表达更为显著.血浆TNF-α含量与肝组织TLR4 mRNA表达呈正相关.结论肝内细胞膜上表达的TLR4可能通过启动下游的炎性应答基因表达及细胞因子释放而诱导出肝组织对LPS的炎性应答.因此,调控TLR4表达可能是感染性疾病防治的一种新策略.     

自拟调气汤灌胃对顺铂诱导大鼠肾损伤的修复作用及其机制

目的 观察自拟调气汤对顺铂诱导大鼠肾损伤的修复作用,并探讨其机制。方法 将90只大鼠随机分为调气汤低剂量组、调气汤中剂量组、调气汤高剂量组、氨磷汀组、模型组、正常对照组各15只,各组均制备肾损伤模型（正常对照组除外）,造模完成后,调气汤低剂量组、调气汤中剂量组、调气汤高剂量组分别灌胃给予10、20、40 g/kg调气汤,氨磷汀组腹腔注射1 mg/kg氨磷汀,模型组和对照组均给予生理盐水,1次/d,连续60 d。全自动生化分析仪检测大鼠血清尿素氮（BUN）、血清肌酐（SCR）,酶联免疫吸附试剂盒检测大鼠肾组织肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)、白介素-1β(IL-1β)、超氧化物歧化酶（SOD）、丙二醛（MDA）,苏木精—伊红（HE）染色法检测大鼠肾组织病理学变化,实时定量聚合酶链式反应（RT-qPCR）及免疫印迹法（Western blot）检测大鼠肾组织Toll样受体4(TLR4)、核转录因子κB(NF-κB)mRNA和蛋白。结果 与正常对照组比较,模型组血清BUN、SCR及肾组织TNF-α、IL-6、IL-1β、MDA水平升高,TLR4和NF-κB蛋白、mRNA...     

血脉通颗粒对动脉粥样硬化小鼠外周血单核细胞TLR4、IL-6、TNF-α的影响

目的 观察血脉通颗粒对动脉粥样硬化（AS）小鼠外周血单核细胞Toll样受体4（TLR4）表达及血浆白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）水平的影响.方法 选择apo E基因敲除（apo E-/-）小鼠,采用高脂饮食法建立AS模型;造模成功后随机分为血脉通组和对照组,每组11只.血脉通组给予血脉通颗粒3.808 mg/（g·d）灌胃,对照组给予相同剂量生理盐水灌胃.6周后处死,眼眶静脉丛采血.采用RT-PCR法检测小鼠外周血单核细胞TLR4 mRNA,流式细胞术测算单核细胞表面TLR4平均荧光强度,ELISA法检测小鼠血浆IL-6和TNF-α.结果 血脉通组外周血单核细胞中TLR4 mRNA的相对表达量为0.22 ±0.07,TLR4荧光强度为25.45±8.30,血浆IL-6、TNF-α水平分别为（10.86 ±4.41）、（36.94±9.46） pg/mL;对照组分别为34.04 ±7.31、0.31±0.09及（18.24±8.21）、（52.82±13.78） pg/mL;两组比较,P均＜0.05.小鼠血浆IL-6、TNF-α水平与单核细胞表面TLR4的表达均呈正相关（r =4.86、0.509,P均＜0.05）.结论 血脉通颗粒可降低AS小鼠单核细胞TLR4表达和血浆IL-6、TNF-α水平,这可能是其抑制血管炎症、治疗AS的机制之一.     

大鼠酒精性肝损害时血浆细胞因子TNF-α、IL-6水平的变化及其意义

目的 探索细胞因子在酒精性肝损害中的作用。方法 采用SD大鼠进行酒精灌胃制作酒精性肝损害的动物模型，对比检测模型组及正常对照组在外源性内毒素刺激前后血浆中谷丙型转氨酶（ALT），肿瘤坏死因子（TNF－α），白细胞介素6（IL－6）水平，同时光镜观察肝组织病理学变化。结果 模型组TNF－α，ALT高于对照组（0．01＜P＜0．05），LPS加强后差别更大（P＜0．01）；模型组IL－6与对照组比较，差别不显著（P＞0．05），采用LPS刺激后差别显著性明显加大（P＜0．01），所有检测数据同肝组织的病理学变化相一致。结论 酒精性肝损害时肝内Kupffer细胞活化，伴随着TNF－α，IL－6的分泌增加。     

清肝活血方对酒精性肝病大鼠肝组织Ⅰ型胶原表达的影响

目的 :观察清肝活血方对酒精性肝病大鼠肝组织 型胶原表达的影响。方法 :4 5只大鼠用乙醇、玉米油、吡唑等制备酒精性肝病大鼠模型 ,随机均分为模型组 ,清肝活血方低、高剂量组 ,小柴胡冲剂组 ,用免疫组化观察肝组织 型胶原的分布 ,RT- PCR法检测大鼠肝组织 型胶原 m RNA表达 ,并与对照组比较。结果 :酒精性肝病大鼠模型表现为肝功能异常 ,以门冬氨酸氨基转移酶 (AST)变化为显著 ,模型组大鼠肝组织在汇管区有少量 型胶原的分布 ,部分向小叶内延伸 ;正常组大鼠几乎无 型胶原 m RNA表达 ,模型组有明显表达 ,清肝活血方高剂量组 型胶原及其 m RNAR的表达均明显下降 (P <0 .0 5 )。结论 :清肝活血方能有效预防酒精引起的肝损伤、肝纤维化的发生、发展 ,其机制可能与其抑制 型胶原 m RNA表达有关     

清肝化瘀颗粒对二乙基亚硝胺所致原发性肝癌大鼠的治疗作用

目的:研究清肝化瘀颗粒对二乙基亚硝胺(DEN)所致原发性肝癌大鼠的治疗作用。方法:将162只雄性SD大鼠随机平均分为模型组、肝复乐组、化疗药组及清肝化瘀颗粒低、中、高剂量组。应用DEN腹腔注射法制备原发性肝癌大鼠模型,分别给予生理盐水10 mL/(kg·d)灌胃,肝复乐组0.94 g/(kg·d)灌胃,氟尿嘧啶注射液50 mg/(kg·w)腹腔注射,清肝化瘀颗粒0.47、0.93、1.86 g/(kg·d)灌胃,连续给药8周。末次给药后各组随机选取6只大鼠解剖,观察肝脏成癌情况,检测血清肝功能。结果:清肝化瘀颗粒组大鼠的肝脏大体与病理组织学癌变程度均较模型组减轻明显;清肝化瘀颗粒组肝指数较模型组显著降低,中、高剂量组肝脏表面癌结节数显著低于模型组(P<0.05);清肝化瘀颗粒可显著降低血清TBIL、GGT、AFU水平(P<0.05或P<0.01),且中、高剂量组以及化疗药组分别具有显著降低血清ALP、AST水平的作用(P<0.05)。结论:清肝化瘀颗粒能够有效缓解DEN诱导原发性肝癌大鼠的肝损伤,改善其肝功能。     

Protective effect of fufanghuangqiduogan against acute liver injury in mice

AIM: To study the effects and possible mechanisms of fufanghuangqiduogan (FFHQ) in mice with acute liver injury (ALI). METHODS: ALI was successfully induced by injecting carbon tetrachloride (CCl4) intra peritoneally and by tail vein injection of Bacillus Calmette Guerin (BCG) and lipopolysaccharide (LPS) in mice, respectively. Each of the two model groups was divided into normal group, model group, FFHQ (60, 120 and 240 mg/kg) treatment groups, and bifendate treatment group. At the end of the experiment, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), content of malondialdehyde (MDA), activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) in liver homogenate were measured by biochemical methods. The activities of tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1) were determined by radio-immunoassay. Hepatic tissue sections were stained with hematoxylin and eosin and examined under a light microscope. RESULTS: In the two models of ALI, FFHQ (60, 120, 240 mg/kg) was found to significantly decrease the serum transaminase (ALT, AST) activities. Meanwhile, FFHQ decreased MDA contents and upregulated the lower SOD and GSH-px levels in liver homogenate. Furthermore, in immunologic liver injury model, FFHQ decreased levels of TNF-α and IL-1 in serum. Histologic examination showed that FFHQ could attenuate the area and extent of necrosis, reduce the immigration of inflammatory cells. CONCLUSION: FFHQ had protective effect on liver injury induced by either CCl4 or BCG+LPS in mice, and its mechanisms were related to free radical scavenging, increasing SOD and GSH-px activities and inhibiting the production of proinflammatory mediators.     

Toll样受体-4小干扰RNA预处理防治小鼠急性肝损伤

目的 观察Toll样受体(TLR)-4小干扰RNA(siRNA)对D-氨基半乳糖盐酸盐/月旨多糖(D-GalN/LPS)诱导的肝损伤小鼠的保护作用.方法 150只雄性C57BL/6小鼠均分为PBS预处理组、阴性对照质粒预处理组、TS4预处理组、TS6预处理组和TS7预处理组.腹腔内联合注射LPS(10 ng/g)及D-GalN(1 mg/g)诱导小鼠急性肝损伤.在D-GalN/LPS联合注射前24及48 h通过尾静脉高压水注射法导人siRNA质粒50 mg/L.末端脱氧核苷酸转移酶介导的dUTP缺口标记术(TUNEL)检测细胞凋亡水平,免疫组织化学法检测肝组织中TLR-4表达,RT-PCR检测TLR-4、TNF-α及巨噬细胞炎性蛋白(MIP)-2 mRNA水平,ELISA检测小鼠血清中MIP-2及TNF-α水平,标准自动分析仪检测血清中ALT及AST水平,苏木精-伊红染色观察肝脏组织学变化,Fisher确切概率法比较各组间小鼠存活率.结果 TLR-4 siRNA可减轻肝细胞坏死、减轻炎性反应,并可显著降低血清转氨酶水平.TS4预处理组(0.065±0.015)比PBS预处理组(0.346±0.062)的TUNEL标记指数(LI)明显降低(t=9.796,P<0.05).TLR-4 siRNA预处理下调TLR-4 mRNA及蛋白表达水平,显著降低TNF-α及MIP-2 mRNA表达及细胞因子水平,显著降低D-GalN/LPS联合诱导的急性肝损伤C57BL/6小鼠的死亡率和肝损伤.结论 TLR-4 siRNA抑制TLR-4表达在防治肝损伤方面可能具有潜在应用价值.     

Modulation of GdCl3 and Angelica sinensis polysaccharides on differentially expressed genes in liver of hepatic immunological injury mice by cDNA microarray

AIM: To study the modulating effect of GdCl(3) and Angelica Sinensis polysaccharides (ASP) on differentially expressed genes in liver of hepatic immunological mice by cDNA microarray. METHODS: Hepatic immunological injury was induced by lipopolysaccharide (LPS ip, 0.2 mg/kg(-1)) in bacillus calmetteguerin (BCG ip, 1 mg/kg(-1)) primed mice; A single dose of 20 mg/kg(-1) GdCl(3) was simultaneously pretreated and 30 mg/kg(-1) ASP (ig, qdX7 d) was administrated when the BCG+LPS was primed. The mice were sacrificed at the end of the 7(th) day after ip LPS for 6 h and the liver was removed quickly. The PCR products of 512 genes were spotted onto a chemical material-coated glass plate in array. The DNAs were fixed to the glass plate after series of treatments. The total RNAs were isolated from the liver tissue, and were purified to mRNAs by Oligotex. Both mRNAs from the normal liver tissue and the liver tissue from the mice with hepatic immunological injury or that pretreated with GdCl(3) or ASP were reversely transcribed to cDNAs with the incorporation of fluorescent dUTP to prepare the hybridization probes. The mixed probes were hybridized to the cDNA microarray. After high-stringent washing, the cDNA microarray was scanned for fluorescent signals and showed differences between the two tissues. RESULTS: Among the 512 target genes, 18 differed in liver tissue of hepatic immunological injury mice, and 6 differed in those pretreated by ASP, 7 differed in those pretreated by GdCl(3). CONCLUSION: cDNA microarray technique is effective in screening the differentially expressed genes between two different kinds of tissue. Further analysis of those obtained genes will be helpful to understand the molecular mechanism of hepatic immunological injury and to study the intervention of drug. Both ASP and GdCl(3) can decrease the number of the differentially expressed genes in liver tissue of mice with hepatic immunological injury.     

Differential effects of pyrrolidine dithiocarbamate on TNF-alpha-mediated liver injury in two different models of fulminant hepatitis

BACKGROUND/AIMS: Pyrrolidine dithiocarbamate (PDTC) is an inhibitor of nuclear factor kappa B (NF-kappaB) activation. The present study aimed to investigate the effects of PDTC on lipopolysaccharide (LPS)-induced liver injury in two different models of fulminant hepatitis. METHODS: Mice infected with Bacillus Calmette Guerin (BCG) were challenged with LPS (0.2 mg/kg) to induce the model of inflammatory liver injury. Mice were injected with D-galactosamine (GalN, 600 mg/kg) and LPS (20 microg/kg) to induce the model of apoptotic liver injury. In the treatment groups, mice were pre-treated with PDTC (100 mg/kg), initiated 24 h prior to LPS. RESULTS: PDTC pretreatment reduced the infiltration of inflammatory cells, inhibited NF-kappaB activation and the expression of tumor necrosis factor alpha (TNF-alpha), attenuated nitric oxide production, and alleviated hepatic glutathione depletion. Correspondingly, PDTC reduced serum alanine aminotransferase, improved hepatic necrosis, and prolonged the survival in the BCG/LPS model. Conversely, PDTC accelerated death and aggravated liver apoptosis in the GalN/LPS model, although it reduced nitric oxide production, attenuated glutathione depletion, and inhibited the expression of TNF-alpha in liver. CONCLUSIONS: PDTC protects mice against BCG/LPS-induced inflammatory liver injury through the repression of NF-kappaB-mediated TNF-alpha release, while it seems to be detrimental in GalN/LPS-induced apoptotic liver damage.     

Inhibition of inducible nitric oxide synthase protects against liver injury induced by mycobacterial infection and endotoxins

BACKGROUND/AIMS: Bacillus Calmette Guerin (BCG) infection causes hepatic injury following granuloma formation and secretion of cytokines which render mice highly sensitive to endotoxin-mediated hepatotoxicity. This work investigates the role of inducible nitric oxide synthase (iNOS) in liver damage induced by BCG and endotoxins in BCG-infected mice. METHODS: Liver injury and cytokine activation induced by BCG and by LPS upon BCG infection (BCG/LPS) were compared in wild-type and iNOS-/- mice. RESULTS: iNOS-/- mice infected with living BCG are protected from hepatic injury when compared to wild-type mice which express iNOS protein in macrophages forming hepatic granulomas. In addition, iNOS-/- mice show a decrease in BCG-induced IFN-gamma serum levels. LPS challenge in BCG-infected mice strongly activates iNOS in the liver and spleen of wild-type mice which show important liver damage associated with a dramatic increase in TNF and IL-6 and also Th1 type cytokines. In contrast, iNOS-/- mice are protected from liver injury after BCG/LPS challenge and their TNF, IL-6 and Th1 type cytokine serum levels raise moderately. CONCLUSIONS: These results demonstrate that nitric oxide (NO) from iNOS is involved in hepatotoxicity induced by both mycobacterial infection and endotoxin effects upon BCG infection and that inhibition of NO from iNOS protects from liver injuries.