thioacetamide and Fatty-Liver

Small- and intermediate-conductance Ca

Topics: Actins; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Line; Collagen; Diet, High-Fat; Fatty Liver; Hepatic Stellate Cells; Humans; Intermediate-Conductance Calcium-Activated Potassium Channels; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Modafinil; Non-alcoholic Fatty Liver Disease; Small-Conductance Calcium-Activated Potassium Channels; Stereoisomerism; Thioacetamide

We investigated the responses of mice that are defective in the superoxide-scavenging enzyme SOD1 to thioacetamide (TAA)-induced hepatotoxicity. When a lethal dose of TAA (500 mg/kg) was intraperitoneally injected, the wild-type (WT) mice all died within 36 h, but all of the SOD1-knockout (KO) mice survived. Treatment with an SOD1 inhibitor rendered the WT mice resistant to TAA toxicity. To elucidate the mechanism responsible for this, we examined the acute effects of a sublethal dose of TAA (200 mg/kg) on the livers of WT and KO mice. The extent of TAA-induced liver damage was less in the KO mice, but, instead, lipogenesis was further advanced in the SOD1-KO livers. The levels of proteins modified with acetyllysine, a marker for TAA-mediated injury, were lower in the KO mice than the WT mice upon the TAA treatment. The KO mice, which were under oxidative stress per se, exhibited a lower CYP2E1 activity, and this appeared to result in a decrease in the production of reactive oxygen species (ROS) during TAA metabolism. Both cleaved ATF6, a transcriptional regulator that is activated by endoplasmic reticulum (ER) stress, and CHOP, a death signal mediator, were highly elevated in the WT mice as the result of the TAA treatment and consistent with the liver damage. We conclude that elevated TAA metabolites and reactive oxygen species that are produced by CYP-mediated drug metabolism trigger lipogenesis as well as liver damage via ER stress and determine the fate of the mice.

Topics: Animals; Antioxidants; Cell Death; Cytochrome P-450 CYP2E1; Endoplasmic Reticulum Stress; Enzymes; Fatty Liver; Inactivation, Metabolic; Lipid Metabolism; Liver; Male; Mice, Inbred C57BL; Mice, Knockout; Oxidative Stress; Superoxide Dismutase-1; Thioacetamide

Nonalcoholic fatty liver disease is one of the most prevalent forms of chronic liver disease in the Western world. Taurine is a conditionally essential amino acid in humans that may be a promising therapy for treating this disease.. To evaluate the effect of taurine on hepatic steatosis induced by thioacetamide in Danio rerio.. Animals were divided into four groups: control (20 μl of saline solution), taurine (1,000 mg/kg), thioacetamide (300 mg/kg), and the taurine-thioacetamide group (1,000 + 300 mg/kg). Thioacetamide was injected intraperitoneally three times a week for 2 weeks. The mRNA expression, lipoperoxidation, antioxidant enzymatic activity, and histological analyses were evaluated in the liver and the triglyceride content was assessed in the serum.. Thioacetamide injection induced steatosis, as indicated by histological analyses. The lipoperoxidation showed significant lipid damage in the thioacetamide group compared to the taurine-thioacetamide group (p < 0.001). Superoxide dismutase (SOD) activity in the taurine-thioacetamide group (5.95 ± 0.40) was significantly increased compared to the thioacetamide group (4.14 ± 0.18 U SOD/mg of protein) (p < 0.001). The mRNA expression of SIRT1 (0.5-fold) and Adiponectin receptor 2 (0.39-fold) were lower in the thioacetamide group than the control (p < 0.05). TNF-α mRNA expression was 6.4-fold higher in the thioacetamide group than the control (p < 0.05). SIRT1 mRNA expression was 2.6-fold higher in the taurine-thioacetamide group than in the thioacetamide group.. Taurine seems to improve hepatic steatosis by reducing oxidative stress and increasing SIRT1 expression.

Topics: Animals; Disease Models, Animal; Fatty Liver; Female; Lipid Metabolism; Lipid Peroxidation; Liver; Male; Oxidative Stress; Receptors, Adiponectin; Sirtuin 1; Taurine; Thioacetamide; Triglycerides; Tumor Necrosis Factor-alpha; Zebrafish; Zebrafish Proteins

The induction of prolonged choline-deprivation (CD) in rats receiving thioacetamide (TAA) is an experimental approach of mild hepatotoxicity that could resemble commonly presented cases in clinical practice (in which states of malnutrition and/or alcoholism are complicated by the development of other liver-associated diseases).. The present study aimed to investigate the time-dependent effects of a 30-, a 60- and a 90-day dietary CD and/or TAA administration on the adult rat liver histopathology and the serum markers of hepatic functional integrity.. Rats were divided into four main groups: (a) control, (b) CD, (c) TAA and (d) CD + TAA. Dietary CD was provoked through the administration of choline-deficient diet, while TAA administration was performed ad libitum through the drinking water (300 mg/l of drinking water).. Histological examination of the CD + TAA liver sections revealed micro- and macro-vesicular steatosis with degeneration and primary fibrosis at day 30, to extensive steatosis and fibrosis at day 90. Steatosis was mostly of the macrovesicular type, involving all zones of the lobule, while inflammatory infiltrate consisted of foci of acute and chronic inflammatory cells randomly distributed in the lobule. These changes were accompanied by gradually increasing mitotic activity, as well as by a constantly high alpha-smooth muscle actin immunohistochemical staining. The determination of hepatocellular injury markers such as the serum enzyme levels' of alanine aminotransferase and aspartate aminotransferase demonstrated a decrease at day 30 (they returned to control levels at days 60 and 90). However, the determination of those serum enzymes used for the assessment of cholestatic liver injury (gamma-glutamyltransferase, alkaline phosphatase) revealed a constant (time-independent) statistically-significant increase versus control values.. Long-term combined dietary CD and TAA administration could be a more realistic experimental approach to human liver diseases involving severe steatosis, fibrosis, stellate cell activation and significant regenerative hepatocellular response.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Choline; Choline Deficiency; Diet; Fatty Liver; Hepatic Stellate Cells; Liver Cirrhosis; Male; Rats; Thioacetamide

The Gas6/Axl pathway has been increasingly implicated in regeneration and tissue repair and, recently, in the control of innate immunity. In liver, we have demonstrated that Gas6 and its receptor Axl are expressed in macrophages, progenitor cells, and myofibroblasts and that Gas6 deficiency reduced inflammation and myofibroblast activation, causing delayed liver repair in response to acute injury. All these data suggest a role of Gas6/Axl signaling in pathogenesis of chronic liver diseases. In the present study, we address the role of Gas6 in steatohepatitis and progression to liver fibrosis using Gas6-deficient mice fed a choline-deficient ethionine-supplemented diet (CDE) or receiving a chronic carbon tetrachloride (CCl(4)) treatment. Gas6 deficiency attenuated hepatic steatosis by limiting CDE-induced downregulation of genes involved in β-oxidation observed in wild-type animals. Moreover, Gas6-deficient mice displayed reduction of hepatic inflammation, revealed by limited F4/80-positive macrophage infiltration, decreased expression of IL-1β, TNF-α, lymphotoxin-β, and monocyte chemotactic protein-1, and attenuated hepatic progenitor cell response to CDE diet. Gas6 deficiency reduced CDE-induced fibrogenesis and hepatic myofibroblast activation and decreased expression of TGF-β and collagen 1 mRNAs. After chronic CCl(4) injury, Gas6-deficient mice also exhibited reduced liver fibrosis as a consequence of defective macrophage recruitment compared with wild-type animals. We conclude that improvement of steatohepatitis and fibrosis in Gas6(-/-) mice is linked to an inhibition of the inflammatory response that controls lipid metabolism and myofibroblast activation. This study highlights the deleterious effect of Gas6 in the progression of steatosis to steatohepatitis and fibrosis.

Topics: Animals; Axl Receptor Tyrosine Kinase; Carbon Tetrachloride; Cell Proliferation; Choline Deficiency; Disease Progression; Ethionine; Fatty Liver; Gene Expression Regulation; Hepatitis; Inflammation Mediators; Intercellular Signaling Peptides and Proteins; Lipid Metabolism; Liver; Liver Cirrhosis, Experimental; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Myofibroblasts; Proto-Oncogene Proteins; Receptor Protein-Tyrosine Kinases; Stem Cells; Thioacetamide; Time Factors

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic condition of the liver in the western world. There is only little evidence about altered sensitivity of steatotic liver to acute toxic injury. The aim of this project was to test whether hepatic steatosis sensitizes rat liver to acute toxic injury induced by thioacetamide (TAA). Male Sprague-Dawley rats were fed ad libitum a standard pelleted diet (ST-1, 10% energy fat) and high-fat gelled diet (HFGD, 71% energy fat) for 6 weeks and then TAA was applied intraperitoneally in one dose of 100 mg/kg. Animals were sacrificed in 24-, 48- and 72-h interval after TAA administration. We assessed the serum biochemistry, the hepatic reduced glutathione, thiobarbituric acid reactive substances, cytokine concentration, the respiration of isolated liver mitochondria and histopathological samples (H+E, Sudan III, bromodeoxyuridine [BrdU] incorporation). Activities of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase and concentration of serum bilirubin were significantly higher in HFGD groups after application of TAA, compared to ST-1. There were no differences in activities of respiratory complexes I and II. Serum tumour necrosis factor alpha at 24 and 48 h, liver tissue interleukin-6 at 72 h and transforming growth factor β1 at 24 and 48 h were elevated in TAA-administrated rats fed with HFGD, but not ST-1. TAA-induced centrilobular necrosis and subsequent regenerative response of the liver were higher in HFGD-fed rats in comparison with ST-1. Liver affected by NAFLD, compared to non-steatotic liver, is more sensitive to toxic effect of TAA.

Topics: Animals; Carcinogens; Cell Proliferation; Cholesterol; Cytokines; Dietary Fats; Disease Models, Animal; Electron Transport Complex I; Electron Transport Complex II; Fatty Liver; Liver; Male; Non-alcoholic Fatty Liver Disease; Rats; Rats, Sprague-Dawley; Thioacetamide; Thiobarbituric Acid Reactive Substances; Triglycerides

Methacetin is thought to be a good substrate for the evaluation of different cytochrome P450 enzymatic systems of liver microsomes because of its rapid metabolism and lack of toxicity in small doses. Recent studies indicate that a methacetin breath test may be a non-invasive alternative for the evaluation of liver function since it correlates well with the severity of liver damage. It may also discriminate between different stages of liver cirrhosis and correlates with the Child-Pugh score. The application of this test in experimental liver damage in animal models has not yet been examined. This study aimed to evaluate the efficacy of the (13)C-methacetin breath test in assessing the extent of hepatic injury in models of acute liver failure, liver cirrhosis, and fatty liver in rats.. Absorption of methacetin given per os or intraperitoneally in normal rats was evaluated. The association between liver mass and (13)C-methacetin breath test results was assessed in a 70% hepatectomy rat model. Fulminant hepatic failure was induced by three consecutive intraperitoneal injections of thioacetamide, 300 mg/kg, at 24 h intervals. For induction of liver cirrhosis, rats were given intraperitoneal injections of thioacetamide, 200 mg/kg, twice a week for 12 weeks. A methionine-choline deficient diet was used for the induction of fatty liver. Rats were analyzed for (13)C-methacetin by BreathID (MBID) using molecular correlation spectrometry. BreathID continuously sampled the animal's breath for 60 min and displayed the results on the BreathID screen in real-time.. Methacetin was absorbed well irrespective of the administration method in normal rats. Liver mass was associated with peak amplitude, complete percent dose recovery (CPDR) at 30 and 60 min and MBID peak time. A high degree of association was also demonstrated with MBID results in acute hepatitis (peak amplitude, 19.6 +/- 3.4 vs 6.3 +/- 1.63.4; CPDR30, 6.0 +/- 3.3 vs 1.2 +/- 0.5; CPDR60, 13.3 +/- 4.5 vs 3.2 +/- 1.4; and peak time, 31.0 +/- 14.9 vs 46.9 +/- 10.8 min) and liver cirrhosis (peak amplitude, 24.4 +/- 2.3 vs 15.6 +/- 6.4; CPDR30, 7.9 +/- 1.2 vs 2.7 +/- 1.0; CPDR60, 17.8 +/- 2.6 vs 8.8 +/- 2.1; and peak time, 30.2 +/- 1.5 vs 59.6 +/- 14.5 min), but not with grade of liver steatosis.. Methacetin is well absorbed and exclusively metabolized in the liver. MBID is a sensitive test and may be a useful tool for the evaluation of functional liver mass in animal models of acute liver failure and cirrhosis. However, MBID could not distinguish between fatty liver and normal liver in rats.

Topics: Acetamides; Administration, Oral; Animals; Breath Tests; Carbon Isotopes; Choline Deficiency; Disease Models, Animal; Fatty Liver; Hepatectomy; Injections, Intraperitoneal; Liver; Liver Cirrhosis; Liver Failure, Acute; Liver Function Tests; Male; Methionine; Organ Size; Predictive Value of Tests; Rats; Rats, Wistar; Severity of Illness Index; Thioacetamide; Time Factors

Hepatocellular carcinoma (HCC) is one of the common cancers worldwide, caused by Hepatitis C virus (HCV) and hepatotoxins. Here we report the development of HCC in wild type as well as HCV core protein (HCP)-transgenic zebrafish upon treatment with a hepatotoxin, thioacetamide (TAA). Two-fold accelerated HCC development could be achieved in the TAA-treated transgenic fish, that is, the progression of the disease in TAA-treated wild type zebrafish developed HCC in 12 weeks whereas that of HCP-transgenic zebrafish shortened the HCC progression to 6 weeks. Histopathological observation showed the specific pathological features of HCC. The HCC progression was confirmed through RT-PCR that revealed an up and down regulation of different marker genes at various stages of HCC progression such as, steatohepatitis, fibrosis and HCC. Moreover, HCV core protein expressed in the HCP-transgenic zebrafish and TAA synergistically accelerate the HCC development. It must be mentioned that, this is the first report revealing HCV core protein along with TAA to induce HCC in zebrafish, particularly, in a short period of time comparing to mice model. As zebrafish has already been considered as a good human disease model and in this context, this HCC-zebrafish model may serve as a powerful preclinical platform to study the molecular events in hepatocarcinogenesis, therapeutic strategies and for evaluating chemoprevention strategies in HCC.

Topics: Animals; Animals, Genetically Modified; Carcinoma, Hepatocellular; Chemical and Drug Induced Liver Injury; DNA Primers; Fatty Liver; Hepacivirus; Liver; Liver Cirrhosis; Liver Diseases; Liver Neoplasms; Microscopy, Confocal; Reverse Transcriptase Polymerase Chain Reaction; Thioacetamide; Viral Core Proteins; Zebrafish

Nonalcoholic steatohepatitis is most often attributed to the effects of obesity, hyperlipidemia, diabetes mellitus and drugs. It is still unknown whether livers with steatohepatitis are more vulnerable to toxic damage.. To determine the effect of the hepatotoxicant thioacetamide in a rat nutritional model of hepatic steatohepatitis.. Fatty liver was induced in rats by placing them on a methionine-choline deficient diet for one month. Thioacetamide was administered by 3 consecutive intraperitoneal injections (300 mg/kg) at 24 h intervals.. Following treatment with thioacetamide, the elevated serum levels of liver enzymes and blood ammonia, liver necrotic inflammation and the survival rate after 48 h were not different between rats with normal or fatty liver. However, those parameters were significantly worse when fatty liver regressed after return to normal diet for one month (p < 0.01). Western blot analysis of hepatic extracts revealed no difference in cytochrome P4502E1 levels between fatty livers and fatty livers after regression, suggesting that the enhanced hepatotoxicity after regression of fatty liver could not be attributed to increased cytochrome P4502E1.. In a nutritional model of steatohepatitis, rats with fatty liver were not more vulnerable than normal rats to liver damage induced by thioacetamide. However, liver damage was significantly more severe in rats with fatty livers after one month regression of steatosis.

Topics: Animals; Choline; Cytochrome P-450 CYP2E1; Fatty Liver; Hepatitis; Liver; Male; Methionine; NF-kappa B; Oxidative Stress; Rats; Rats, Wistar; Thioacetamide

Rats were treated with a hepatotoxin thioacetamide (TAA) and examined 21 days later, when they showed moderate fatty metamorphosis of the liver and morphological changes in brain indicative of excitotoxic neuronal damage, but no evident biochemical or neurophysiological symptoms of hepatic encephalopathy (HE). High-performance liquid chromatography (HPLC) analysis of extracellular amino acids in striatal microdialysates of TAA-treated rats revealed a significant increase in the excitatory amino acids glutamate (Glu) and aspartate (Asp) and their amino acid metabolites glutamine (Gln) and alanine (Ala). Microdialysis in the presence of 50 mM K+ triggered in TAA-treated rats an accumulation of Asp and Glu, and diminished the accumulation of Gln. These effects were virtually absent in control rats. None of the treatments affected the accumulation of the nontransmitter amino acid leucine (Leu). The above changes mirror those previously described in symptomatic HE and are likely to contribute to excitotoxic damage. The basal microdialysate content of taurine (Tau), an amino acid with antioxidant and volume regulatory properties, was 60% lower in TAA-treated rats than in control rats despite its increased blood-to-brain transport. The decrease in extracellular Tau may thus reflect Tau redistribution to adjacent central nervous system (CNS) cells manifesting a cell-protective response. Stimulation with 50 mM K+ increased extracellular Tau in control rats by 182% and in TAA-treated rats by 322%. Stimulation with 100 microM N-methyl-D-aspartate (NMDA) increased extracellular Tau in control rats by 27 % and in TAA-treated rats by as much as 250%. The increase of K+- or NMDA-dependent Tau release may reflect improved cell volume regulation and neuroprotection and contribute to attenuation of neurologic symptoms in rats with liver failure.

Topics: Alanine; Amino Acids; Animals; Aspartic Acid; Biological Transport; Corpus Striatum; Excitatory Amino Acids; Fatty Liver; Gliosis; Glutamic Acid; Glutamine; Hepatic Encephalopathy; Liver; Male; Microdialysis; Potassium; Rats; Rats, Wistar; Taurine; Thioacetamide

The administration of thioacetamide in rats induces nodular cirrhosis of the liver, characterized by fibrous septae, parenchymal nodules, proliferation of the bile ducts, and excessive deposition of connective tissue elements. Nodular cirrhosis is also associated with changes in lipid metabolism, as shown by the accumulation of lipid droplets in the hepatocyte cytoplasm. Adequate nutritional support during cirrhosis is important to sustain liver function and promote recovery after the lesions have been induced. Supplementation with nucleotides may increase cellular proliferation and thus optimize hepatic recovery. The aim of this study was to investigate the effects of dietary nucleotide supplementation on the degree of fibrosis and steatosis in rats with liver cirrhosis induced by four months of oral intake of thioacetamide. The use of dietary nucleotides after thioacetamide administration was found to decrease the percentage area of fibrous septae. In animals with liver cirrhosis fed the nucleotide-supplemented diet for two weeks, the total area of fibrosis was reduced. Withdrawal of the hepatotoxic agent led to a decrease in the degree of steatosis in cirrhotic animals, which was significant in rats given the nucleotide-supplemented diet during a two-week recovery period. In conclusion, dietary nucleotides may be an important factor in the histological recovery of damaged liver in experimental cirrhosis.

Topics: Animals; Carcinogens; Diet; Fatty Liver; Female; Liver Cirrhosis, Experimental; Nucleotides; Rats; Rats, Wistar; Thioacetamide

By means of statistical pattern recognition procedures, a quantitative description of the ultrasound B-scan images of experimental diffuse liver disease has been carried out. Fatty livers, fatty fibrosis/cirrhosis, and cirrhosis without fatty infiltration of the liver were studied in female Wistar rats. Separation accuracies of more than 80% between the tissue classes "normal" vs "fatty infiltration," or "normal" vs "fatty cirrhosis," using only two statistical image parameters were found. A subclassification of the diffuse parenchymal liver disease was not possible. It is shown by multiple linear regression analysis that the image parameter "mean grey level" correlates better with total lipid content than with the amount of connective tissue. Furthermore it is demonstrated that connective tissue leads only to a weak increase in "mean grey level," whereas the addition of connective tissue to a given tissue lipid can lead to a reduction in image brightness.

Topics: Animals; Carbon Tetrachloride Poisoning; Connective Tissue; Fatty Liver; Female; Image Processing, Computer-Assisted; Liver Cirrhosis, Experimental; Rats; Rats, Inbred Strains; Thioacetamide; Ultrasonography

Acute intoxication of the rat liver with a single dose of 100 mg thioacetamide (TAA)/kg body weight causes within 48 h a fatty liver and a heterogeneous reaction in the hepatocytes. This affects principally the centrilobular liver parenchymal cells (zone 3) and to a lesser extent the periportal ones (zone 1). Ultrastructural analysis was performed to determine to what extent the formation of lipid-carrying particles of the very low density type (VLDL) is changed in affected hepatocytes in zones 1 and 3. Being morphologically the most conspicuous site of VLDL processing, the Golgi complex was chosen for quantitation by measuring its volume, VLDL content and particle size. The concentration and composition of the liver lipids were determined, biochemically. After TAA treatment of the liver the number of Golgi-VLDL particles is significantly reduced to about 50% in both the lobular zones examined. In addition, distinct classes of size-modified Golgi-VLDL particles appear which show an abnormally wide size distribution pattern. In periportal hepatocytes the size distribution of Golgi-VLDL particles shows a clear shift towards smaller particles homogeneous in size (mean diameter 39 nm). In contrast, centrilobular hepatocytes contain particles of very heterogeneous size, the mean diameter of which is nearly doubled (77 nm). The decrease in VLDL particle number and their size modification induced by TAA is not accompanied by significant changes in the volume of the Golgi complex. Biochemical analysis showed that the accumulation of lipids in the TAA-treated liver, mainly evident morphologically as drop-like deposits in the central area of the liver lobules, is due to an increase in triglycerides (TG) by 23 mumol/g liver wet weight, which represents nearly 95% of the accumulated lipids. Despite the striking elevation of the absolute cholesterol ester (CHOL-E) content (2 mumol/g liver wet weight), this corresponds to only 5% of the newly accumulated lipids. Our electron optical and biochemical results support the suggestion that, in spite of the markedly different intralobular reaction of TAA-intoxicated hepatocytes, the formation of triglyceride-carrying particles is altered significantly in both lobular zones examined.

Topics: Acetamides; Animals; Cholesterol Esters; Fatty Liver; Female; Golgi Apparatus; Lipoproteins; Lipoproteins, VLDL; Liver; Microscopy, Electron; Rats; Rats, Inbred Strains; Thioacetamide; Time Factors; Triglycerides

Topics: Animals; Carbon Tetrachloride; Fatty Liver; Liver; Male; Mice; Mice, Inbred Strains; Panax; Plants, Medicinal; Rats; Saponins; Sulfobromophthalein; Thioacetamide

Topics: Acid Phosphatase; Alkaline Phosphatase; Animals; Carbon Tetrachloride Poisoning; Chemical and Drug Induced Liver Injury; Cholestasis; Cholinesterases; Clinical Enzyme Tests; Diagnosis, Differential; Ethionine; Fatty Liver; Fructose-Bisphosphate Aldolase; Fructosephosphates; Necrosis; Phenobarbital; Proadifen; Rats; Thioacetamide