Pharmacokinetics of phenol red in rat models of liver damage prepared by liver targeting of carbon tetrachloride

Animal models prepared by treatment with carbon tetrachloride (CCl(4)) have been used to examine drug disposition in hepatic disorder. However, previous studies demonstrated that systemic administration of CCl(4) impaired not only hepatic but also renal function. We recently reported that application of CCl(4) to the rat liver surface produced hepatic damage without impairing renal function. In the present study, we examined the pharmacokinetics of phenol red in our developed rat model. The rats treated with CCl(4) by liver surface application exhibited decreases in the biliary clearance of phenol red in comparison with normal rats from 0.54+/-0.03 to 0.31+/-0.06 ml/min, suggesting hepatic damage. In these rats, the renal clearance of phenol red did not decrease (0.50+/-0.16 ml/min vs. 0.46+/-0.07 ml/min in normal rats). On the other hand, oral and intraperitoneal treatments with CCl(4) reduced not only the biliary clearance of phenol red (0.34+/-0.03 ml/min in p.o. treated rats, 0.18+/-0.01 ml/min in i.p. treated rats) but also the renal clearance (0.26+/-0.05 ml/min in p.o. treated rats, 0.18+/-0.06 ml/min in i.p. treated rats) as compared with normal rats. These findings indicate that the rat model of liver damage prepared by liver surface application of CCl(4) is useful to investigate the effects of hepatic disorder on the pharmacokinetics of drugs.     

Hepatoprotective effects of diethylcarbamazine in acute liver damage induced by carbon tetrachloride in rats

This research was carried out to determine a potential role of leukotrienes in the acute hepatotoxicity induced by CC14 in rats. An inhibitor of leukotrienes biosynthesis, diethylcarbamazine (DEC, 25 and 50 mg ·kg-1 ip) exerted hepatoprotective effects, decreasing the activity of alanine aminotransfer-ase in serum and the concentration of liver triglycerides. DEC reduced histological damage of liver evidenced by electron microscopy. The hepatoprotective effects of DEC were dose-dependent. The results favor the role of leukotrienes in CC14 hepatotoxicity.     

四氯化碳对大鼠肝毒性的时量关系研究

目的：探讨四氯化碳随用药时间和剂量的变化对大鼠肝脏功能与组织形态学的损害的时量关系，进一步了解四氯化碳对肝脏的毒理学作用。为研究护肝药提供动物实验模型，方法：大鼠皮下注射60％四氯化碳花生油，每周2次，分别在实验1、3、5、7、9wk观察大鼠血清丙氨酸氨基转移酶（ALT／GPT）、天冬氨酸氨基转氨酶（AST／GOT）、总蛋白（TP）和白蛋白（Alb)，血清透明质酸及肝组织病理变化和内脏器官重量指数的改变，以判断肝脏受损程度。结果：四氯化碳对大鼠肝脏的影响表现在1wk内可致大鼠血清ALT升高，3wk时发生肝组织脂变，5wk时肝组织轻度纤维增生，7wk时肝组织呈纤维化改变，9wk时肝组织发生明显的肝纤维化，甚至肝硬化。结果：大鼠皮下注射60％四氯化碳随染毒时间延长，染毒剂量的增加，对肝脏的毒性也不断加重。     

Protein deficiency and muscle damage in carbon tetrachloride induced liver cirrhosis

Protein undernutrition, alterations of hormones such as IGF-1, testosterone and cortisol, and increased lipid peroxidation—which may be related with deranged metabolism of some elements such as iron (Fe), zinc (Zn), manganese (Mn), selenium (Se) or copper (Cu)—may contribute to muscle damage in non alcoholic cirrhosis. Here, we analyse the effect of protein deficiency on muscle Cu, Fe, Zn, Mn and Se in carbon-tetrachloride (CCl₄) induced liver cirrhosis. We also study the association between protein undernutrition and these trace elements with the activity of glutathione peroxidase (GPX), superoxide dismutase (SOD) and lipid peroxidation products, and how all these are related with muscle morphological changes in 40 male adult Sprague-Dawley rats. Liver cirrhosis was induced by intraperitoneal injection of CCl₄ to 10 rats fed a 2% protein diet, and to another 10 fed a 18% protein control diet. Two further groups included rats without cirrhosis fed the 2% protein and the 18% protein diets. After sacrifice (6 weeks later), we found type IIa fibre atrophy in the cirrhotic animals, especially in the low-protein fed ones and this was due to protein deficiency. Muscle Fe increased in low protein fed cirrhotic rats. No relationship was found between muscle changes and any of the hormones, enzymes and trace elements analysed, or with liver fibrosis. These results suggest that muscle atrophy observed in CCl₄-induced cirrhosis is related with protein deficiency, but not with cirrhosis itself.     

大黄酸抑制四氯化碳诱导的大鼠肝纤维化形成

目的:观察大黄酸对实验性肝纤维化的影响.方法:采用60％的四氯化碳(CCl_4)及5％的乙醇制备肝纤维化动物模型,分别用小剂量、大剂量大黄酸(25 mg/kg,100 mg/kg体重)干预,测定血清丙氨酸氨基转移酶(ALT)、透明质酸(HA)、Ⅲ型前胶(PC-Ⅲ)及肝组织丙二醛(MDA)含量,免疫组化方法观察转化生长因子 β1(TGF-β1)、α平滑肌肌动蛋白(α-SMA)的表达情况,并观察肝组织胶原面积及病理变化.结果:大黄酸组较模型组:(1)血清ALT、HA、PC-Ⅲ水平及肝组织中MDA含量显著降低(P<0.01);(2)肝组织中TGF-β1,α-SMA的表达显著减少(P<0.05或P<0.01);③肝组织胶原面积明显减少,纤维化程度明显改善(P<0.05或P<0.01).结论:大黄酸具有保肝作用和抑制肝纤维化作用,其作用机制可能与其抗炎、抗氧化作用及抑制HSC活化、抑制TGF-β1作用有关.     

Effects of adenosine on liver cell damage induced by carbon tetrachloride

Adenosine administration delayed the fatty liver and cell necrosis induced by carbon tetrachloride without affecting the action of the hepatotoxin on protein synthesis and liver triacylglycerol release. Adenosine produced a drastic antilipolytic effect accompanied by a decrease in the incorporation of [1-14C]palmitic acid into triacylglycerols and free fatty acids of the liver. Furthermore, a decrease in the serum levels of ketone bodies was observed at early times. The nucleoside also avoided the release of intracellular enzymes and prevented the lipid peroxidation produced by carbon tetrachloride during the 4 hr of treatment. The protective action of adenosine was transient, lasting 3-4 hr, probably the time required to be metabolized. The results suggest that the antilipolytic effect of the nucleoside, the inhibition of hepatic fatty acid metabolism, and the decrease in carbon tetrachloride-induced lipoperoxidation that it produced are involved in the delayed acute hepatotoxicity induced by carbon tetrachloride.     

芦根多糖对四氯化碳小鼠肝损伤的保护作用

芦根 (Ｒｈｉｚｏｍａｐｈｒａｇｍｉｔｉｓ)是芦苇 (ｐｈｒａｇｍｉｔｅｓｃｏｍｍｕｎｉｓＴｒｉｎ)的地下根茎。传统中医药认为芦根具有养阴、清热、利尿、退黄疸和解毒等功用 ,对维持体液平衡 ,清除体内毒物起一定作用[1] 。研究发现Ｐ Ｐｏｌｙ分子量2 0 0 0 0 ,由葡萄糖 ,木糖、阿拉伯糖残基构成并含有 β(1→ 3)苷键的支链。具有很强的抗氧化功能 ,对化学毒品的肝损伤起到良好的保护和增进健康的作用[2 ,3 ] 。1　材料1.1　药品与试剂　芦根多糖 (Ｐ Ｐｏｌｙ)由本院有机化学教研室用鲜芦根经 5～ 8倍水煎煮 ,每次 2ｈ ,低温浓缩 ,醇…     

Effect of 'Arogyavardhini' against carbon tetrachloride induced hepatic damage in albino rats

'Arogyavardhini'-an indigenous formulation was evaluated for its hepatoprotective activity in rats, using two models of carbon tetrachloride (CCl4) hepatic damage, one simulating vital hepatitis and the other simulating fatty change. The protective effect was assessed from serum aspartate transaminase (AST) and alkaline phosphatase levels and from histopathological changes in liver. The results revealed that 'Arogyavardhini' (5 mg/100g, PO daily) was effective in minimizing the changes in serum levels of AST and alkaline phosphatase induced by CCI. The protective effect was also evident on histopathological examination.     

Early biochemical alterations in liver mitochondria from carbon tetrachloride poisoned rats

Covalent binding of reactive metabolites of 14CCl4 were found 1 or 3 h after treatment with the solvent in the lipid and protein fractions of highly purified liver mitochondrial of rats. Most of the label was found in the phospholipid (PL) fraction, much less in cholesterol esters (ChE), and only minor quantities in other lipids. The reactive metabolites of 14CCl4 activated by isolated mitochondria interact mostly with ChE and far less with PL and other fractions. Both in vivo and in vitro covalent binding to PL is decreasing in the following order: phosphatidylethanolamine greater than diphosphatidylglycerol greater than phosphatidylcholine greater than sphingomyelin greater than lysophosphatidyl choline. No evidence of lipid peroxidation was found in liver mitochondrial lipids in the first 6 h and only a slight tendency of decrease in arachidonic acid concentration at 24 h. The incorporation of [14C] leucine in mitochondrial, microsomal or cytosolic proteins decreased as early as 1 h after treatment. These results, in agreement with previous reports suggest the existence of multiple sites in liver cells for the activation of CCl4. The transport of altered phospholipids and proteins and the inhibition of protein synthesis might contribute to the propagation of damage from the endoplasmic reticulum to other organelles.     

褪黑素对四氯化碳小鼠肝损伤的保护作用

目的　探讨褪黑素对四氯化碳肝毒性的保护作用。方法　给予小鼠四氯化碳（５ ｍｌ·ｋｇ － １ ） ,继后每隔６ ｈ ｉｐ 褪黑素１０ ｍ ｇ·ｋｇ － １ 。用胶原酶消化法分离小鼠肝细胞后,依次加用褪黑素（１０ － ５ ～１０ － １ １ ｍｏｌ· Ｌ－ １ ） 和四氯化碳（２０ ｍ ｍ ｏｌ· Ｌ－ １ ） 。以测定丙氨酸氨基转换酶（ Ａ Ｌ Ｔ） ,丙二醛（ Ｍ Ｄ Ａ） 和谷胱甘肽过氧化物酶活力,作为四氯化碳肝损伤的指标。用 Ｍ Ｔ Ｔ 法检测肝细胞活力。结果　四氯化碳可使小鼠血液 Ａ Ｌ Ｔ 活性和肝 Ｍ Ｄ Ａ 含量明显上升。体内应用 Ｍ Ｔ １０ ｍ ｇ·ｋｇ － １ ,则明显降低肝匀浆 Ｍ Ｄ Ａ 含量（ Ｐ＜ ００１） , 对血浆 Ａ Ｌ Ｔ 活性无明显影响。体外应用 Ｍ Ｔ（１０ － ５ ～１０ － ７ ｍｏｌ· Ｌ－ １ ） 亦可使肝细胞 Ｍ Ｄ Ａ 含量下降（ Ｐ＜ ００５） ,同时还可使肝细胞 Ａ Ｌ Ｔ 释放率下降,细胞活力上升（ Ｐ＜ ００５） 。结论　 Ｍ Ｔ 拮抗 Ｃ Ｃｌ４ 肝毒性的作用可能与其抗氧化能力有关     

Protective action of dithiocarbamates on experimental liver damage produced by carbon tetrachloride

The protective action of dithiocarbamates on CCl₄-induced liver damage in rats was assessed with liver function tests (BSP retention test and SGPT). When given immediately before CCl₄, all dithiocarbamates tested showed a protection against CCl₄ hepatotoxicity except for zineb and some “polymer” dithiocarbamates. For zineb it appears plausible that this was caused by a delayed absorption. No protection was found when one of the dithiocarbamates studied was given 1 hr after CCl₄ administration. From studies with some metabolites and related compounds it appears that only substances containing a carbon disulphide group have a protective action. Probably these compounds function as effective free radical scavengers. In addition, inhibition of microsomal liver enzyme activity and a lowering of body temperature could also be contributing factors.     

Induction of metallothionein in the liver of carbon tetrachloride intoxicated rats: an immunohistochemical study

Metallothioneins (MTs), are low molecular weight proteins, mainly implicated in metal ion detoxification. In the present study, we investigated the expression of hepatic MT in a rat model of injury and regeneration, induced by carbon tetrachloride (CCl(4)) administration. A single intraperitoneal injection of 1 ml CCl(4)/kg body weight was performed in male Wistar rats, killed at different time points post-administration. The enzymatic activities of aspartate and alanine aminotransferases in serum were determined, in addition to the liver histological findings, to estimate hepatotoxicity. The rate of tritiated thymidine incorporation into hepatic DNA, the enzymatic activity of thymidine kinase in liver tissue and the assessment of the mitotic index in hepatocytes, were used as indices of regeneration. MT was detected immunohistochemically in liver tissue sections. CCl(4) administration caused severe hepatic injury, followed by regeneration. MT expression became prominent as early as 12 h after the administration of CCl(4), in the nuclei of hepatocytes, while at 24 and 36 h intense cytoplasmic staining for MT appeared in the hepatocytes in the vicinity of necrotic areas. The peak of hepatocyte proliferative capacity, occurring at 48 h post-CCl(4) administration coincides with the maximum nuclear and cytoplasmic MT expression. At further time points MT expression presented a decreasing trend. Induction of MT expression was observed in the liver after a single administration of CCl(4), being more prominent at the time of maximum hepatocellular proliferation, participating actively in the replication of hepatocytes.     

Multiple treatment of propolis extract ameliorates carbon tetrachloride induced liver injury in rats

Propolis, a resinous wax-like beehive product has been used as a traditional remedy for various diseases due to a variety of biological activities of this folk medicine. In the present investigation, an attempt has been made to validate hepatoprotective activity of ethanolic extract of propolis (50-400mg/kg, p.o.) against carbon tetrachloride (CCl(4,) 0.5 ml/kg, p.o.) induced acute liver injury in rats. Silymarin, a known hepatoprotective drug was used as a positive control. Administration of CCl(4) altered various diagnostically important biochemical variables. Multiple treatment of propolis significantly prevented the release of transaminases, alkaline phosphatase, lactate dehydrogenase, gamma-glutamyl transpeptidase, urea and uric acid in serum; improved the activity of hepatic microsomal drug metabolizing enzymes, i.e., aniline hydroxylase and amidopyrine-N-demethylase; significantly inhibited lipid peroxidation and markedly enhanced glutathione in liver and kidney as well as brought altered carbohydrate contents (blood sugar and tissue glycogen), protein contents (serum, microsomal and tissue protein) and lipid contents (serum and tissue triglycerides, serum cholesterol, total and esterified cholesterol in tissue) towards control. Propolis treatment also reversed CCl(4) induced severe alterations in histoarchitecture of liver and kidney in a dose dependent manner. Hepatoprotective activity of propolis at doses of 200 and 400 mg/kg was statistically compared to silymarin and found that propolis exhibited better effectiveness than silymarin in certain parameters, concluded its hepatoprotective potential.     

Interaction of carbon tetrachloride and progesterone metabolism in liver microsomes from triacetyloleandomycin-treated rats

The production of progesterone metabolites by rat liver microsomes from TAO-treated rats was investigated. More than ten metabolites could be identified, including various dihydroxy-progesterones. CCl₄ co-incubation modifies the P-450-dependent progesterone metabolite profile in a remarkable fashion without production of CCl₄ progesterone adducts.Dedicated to Professor Dr. med. Herbert Remmer on the occasion of his 65th birthday     

Serum bile acids and other liver function tests in hepatocellular damage from carbon tetrachloride ingestion

The deliberate ingestion of carbon tetrachloride by a 48-year-old woman provided an opportunity to study the sequential biochemical changes of a severe but self-limited event of hepatocellular damage. The initial phase of cellular injury characterised by high levels of serum aspartate aminotransferase, ferritin and bile acids was followed by a period of partial cholestasis. This was indicated by a marked decrease in secondary bile acids and small rises in alkaline phosphatase and 5' nucleotidase. Improving liver function and regeneration became evident during this period and was associated with abnormal levels of gamma glutamyl transpeptidase. A late rise in serum ferritin and alphafetoprotein may represent a non-specific inflammatory reaction.