Dose response and time course studies on superoxide dismutase as a urinary biomarker of carbon tetrachloride-induced hepatic injury in the Hanover Wistar rat

Previous studies have shown that the enzyme copper/zinc superoxide dismutase (SOD-1) is increased in the urine of rats with carbon tetrachloride (CCl₄)-induced hepatotoxicity. The present experiments aimed to investigate further the usefulness of urinary SOD-1 as a non-invasive biomarker of liver injury. Two investigations were carried out, a dose response study and a time course study. In the dose response study, rats were given a single dose of CCl₄ at 0 (control), 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40 and 0.80 ml/kg and urine samples collected from 12 to 36 h postdosing. In the time course study, rats were dosed at 0.80 ml/kg CCl₄ and urine sampled at 4, 12, 24 and 36 h postdosing. In both studies, the presence of SOD-1 in the urine was confirmed by Western blotting with an SOD-1 antibody. In the dose response study, serum SOD activity was elevated in all CCl₄-treated animals and urinary SOD-1 activity was increased 2.2 times at the lowest dose (0.10 ml/kg) and 60.4 times at the highest CCl₄ dose level (0.80 ml/kg). In the time course study, urinary SOD-1 was first detected in samples collected from 4 to 12 h postdosing. We conclude that urinary SOD-1 has potential as a sensitive non-invasive biomarker of CCl₄-induced hepatocellular injury.     

In situ evaluation of the stimulatory state of hepatic macrophages based on their ability to produce superoxide anions in rats

When a liver perfusion with nitro blue tetrazolium (NBT) and phorbol myristate acetate (PMA) was performed in carbon tetrachloride (CCl4)-intoxicated rats, formazan deposition was remarkable in macrophages in the necrotic areas of the liver, its intensity varying with the extent of injury. The deposits almost disappeared after addition of Cu(Lys)2, a scavenger of intra- and extracellular superoxide, but were not affected by superoxide dismutase (SOD), which acts extracellularly. The formazan content after incubation with NBT and PMA was higher in macrophages isolated from CCl4-intoxicated liver than in those from normal liver, though their PMA-induced chemiluminescence did not differ. In Corynebacterium parvum-treated liver, both Cu(Lys)2 and SOD reduced the deposits. This method can estimate in situ the ability of hepatic macrophages to produce superoxide and the cellular sites of its production.     

Effect of prenatal lead exposure on superoxide dismutase activity in the brain and liver of rat fetuses

Prenatal lead exposure had a damaging effect on Cu/Zn superoxide dismutase activity in the brain and liver of rat fetuses (20 days of gestation). The decrease in Cu/Zn superoxide dismutase activity in the brain and liver of treated fetuses reflects activation of free radical processes and impairment of the antioxidant defense system during prenatal lead exposure. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 12, pp. 632–634, December, 2007     

Synergism between ethanol and carbon tetrachloride in the generation of liver fibrosis

In this study, alcohol-induced histological lesions in a short-term experimental rat model were compared with those characteristic of human alcoholic liver disease. In the rat model used, pretreatment with carbon tetrachloride (CCl4) for 6 weeks was employed possibly to sensitize the liver for the effects of alcohol and shorten the time of induction of alcoholic liver disease. After 6 weeks of CCl4 treatment, subsequent maintenance on drinking water containing up to 10 per cent alcohol for 7 weeks potentiated liver fibroplasia as compared with non-alcohol-treated rats. However, steatosis and alcoholic hepatitis, as histological evidence for alcoholic liver disease as seen in humans, were not observed. In non-CCl4-pretreated control animals, alcohol administration had no effect on liver histology. It can be concluded that in the model used, CCl4 pretreatment sensitizes the liver to increase collagen deposition following alcohol administration, but not to steatosis or alcoholic hepatitis as seen in human alcoholic liver disease. In this experimental set-up, direct metabolic interaction of CCl4 with alcohol as a cause of the increased fibroplasia can be excluded.     

异甘草酸镁干预肝纤维化大鼠肝细胞体积与数量的体视学

目的:探讨异甘草酸镁(MgIG)对四氯化碳(CCl4)致大鼠肝纤维化模型肝细胞数量与体积的影响.方法:雄性SD大鼠随机分为对照组、模型组、治疗组,治疗组给予CCl4皮下注射,同时每日腹腔注射MgIG?30 mg/?kg.各组大鼠在造模5周后取材,从每只大鼠等距抽选4个2 mm厚的肝组织块制作石蜡包埋切片,行Masson...     

肝纤维化时肝脏OPN和PAI-1的表达变化

目的:研究骨桥蛋白(OPN)及纤溶酶原激活物抑制物(PAI-1)的表达特征及其在肝纤维化时的变化。方法:采用二甲基亚硝胺制作大鼠肝纤维化模型,大鼠肝脏常规HE和天狼猩红染色,采用SABC法做免疫组织化学染色及Western blotting检测OPN和PAI-1蛋白表达,抽提肝组织总RNA,RT-PCR检测OPN mRNA表达。结果:正常大鼠肝组织OPN和PAI-1表达极弱,肝纤维化大鼠肝脏中OPN表达增强,阳性信号散在或弥漫性分布,主要见于小叶内中央静脉周围、纤维间隔内以及周围巨噬细胞胞浆、枯否氏细胞、汇管区的部分肝细胞、肝窦壁内皮细胞。PAI-1在肝纤维化大鼠肝组织汇管区、肝细胞变性坏死处,肝窦周Disse间隙及毗邻以上部位的肝细胞,组织纤维间隔处及其外周细胞亦见阳性染色。Western blotting检测正常大鼠肝脏OPN的蛋白表达极低,肝纤维化组OPN的蛋白表达较正常组显著增强(P0.01)。与正常组比,肝纤维化组PAI-1表达也显著增强。RT-PCR检测结果显示,正常大鼠肝脏OPN mRNA表达极低,肝纤维化大鼠肝脏OPN mRNA的表达明显增强(P0.05)。研究结果证明,肝纤维化时大鼠肝组织OPN及PAI-1的表达水平显著增高。结论:肝纤维化时大鼠肝组织OPN及PAI-1的表达水平显著增高,OPN可能会促进PAI-1的高表达,从而抑制ECM降解、加速肝纤维化进程。     

芪丹颗粒剂对大鼠肺纤维化模型的干预作用及对TGF-β1、TNF-α表达的影响

目的：探讨芪丹颗粒剂对博莱霉素A5所致大鼠肺纤维化的干预作用及可能的机制。 方法： SD大鼠经气管内一次性灌注博莱霉素A5(5 mg/kg)诱导肺纤维化，随后分别每日给予芪丹颗粒剂灌胃（芪丹组，3 125 mg/kg）、氢化可的松腹腔注射（氢可组，25 mg/kg）进行干预。对照组气管内灌注和灌胃均用生理盐水。各组动物均于药物干预后第7、14、28 d分别处死。用苏木素-伊红（HE）评价肺组织病理学变化、免疫组化（SABC法）测定肺组织TGF-β1、TNF-α蛋白的表达。 结果： 芪丹组肺泡炎及肺纤维化程度均明显轻于模型组和氢可组，TGF-β1、TNF-α蛋白的表达亦显著低于模型组和氢可组（P<0.01）。 结论： 芪丹颗粒剂可明显减轻博莱霉素A5诱导的大鼠肺纤维化的程度, 其作用机制可能部分通过降低TGF-β1、TNF-α蛋白的表达而实现。