Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.2 (alanine aminotransferase)
 26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study examined the preventive effects of green tea extract on D-galactosamine (GalN)-induced hepatic injury in rats, an animal model of viral hepatitis. A single i.p.-injection of GalN (700 mg/kg) to male Wistar rats caused fulminant hepatitis by 48 hr as assessed by marked increases in the serum aspartate aminotransferase (GOT), alanine aminotransferase (GPT) and alkaline phosphatase (ALP) activities; decreases in the serum protein and cholesterol levels and the amount of liver microsome P-450; and marked changes in organ weights. The lecithin: cholesterol acyltransferase (LCAT) activity markedly increased at 8 hr and markedly decreased at 24 hr after the GalN injection. In the experiment, animals were orally administered green tea extract at doses of 50, 100 or 200 mg/kg five times each before and after the GalN injection. Treatment with green tea extract significantly prevented the increases in the GOT, GPT and ALP activities in a dose-related manner. It also significantly prevented the decreases in serum albumin and total cholesterol, although not in a dose-related manner. A tendency to prevent the increase in LCAT activity and the decrease in liver microsome P-450 was also noted. Little effect was found on the other abnormal changes in the serum lipids and proteins and the organ weights. These results suggest that green tea may have an ameliorating effect on hepatic dysfunction.
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PMID:[Effects of green tea extract on galactosamine-induced hepatic injury in rats]. 146 98

N-(2-Hydroxypropyl)methacrylamide (HPMA) copolymers containing doxorubicin (DOX) and galactosamine can be targeted to the hepatocyte galactose receptor for organ-specific chemotherapy of primary and metastatic liver cancer. Here we report the dose-dependent pharmacokinetics of this macromolecular conjugate. Following intravenous administration to mice most efficient liver targeting was seen at low dose (0.05 mg DOX kg-1), with receptor saturation observed using higher bolus doses. Repeated low dose bolus injections did not cause down-regulation of the galactose receptor and targeted drug delivery rates of greater than or equal to 2 micrograms DOX g-1 liver h-1 were achieved. DOX is released from such conjugates intracellularly via action of lysosomal proteinases. It was shown that isolated rat liver lysosomal enzymes (Tritosomes) can release unmodified DOX from the peptidyl side chain Gly-Phe-Leu-Gly at a rate greater than or equal to 3 micrograms DOX g-1 liver h-1 i.e. the hydrolytic capacity is greater than the observed rate of drug delivery to the liver lysosomes in vivo. Although most conjugate would be captured by normal hepatocytes following intravenous administration, it was shown that the human hepatoma cell line HepG2 retains the galactose receptor, accumulating and processing the conjugate efficiently. Potential dose limiting toxicities of such drug conjugates could include cardio- or hepatotoxicity. Administration of conjugate reduced the 15 min heart level of DOX approximately 100-fold compared with that observed for an equivalent dose of free drug. Preliminary experiments showed that plasma levels of alkaline phosphatase, alanine transaminase and asparate transaminase did not change following administration of HPMA copolymer-daunorubicin (DNR) (10 mg DNR kg-1) indicating no significant heptatoxicity.
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PMID:N-(2-hydroxypropyl)methacrylamide copolymers targeted to the hepatocyte galactose-receptor: pharmacokinetics in DBA2 mice. 164 46

Lead markedly augments the lethality of endotoxin lipopolysaccharide (LPS) in rats. In this model of LPS toxicity, the liver is severely injured. Much of the tissue injury produced by LPS is thought to be mediated by the cytokine tumor necrosis factor (TNF). Tumor necrosis factor recently has been speculated to be a mediator of several models of liver injury such as that produced by galactosamine. To investigate the possible role of TNF in the lead-enhanced LPS toxicity model, we administered doses of lead acetate (15 mg/kg), LPS (100 micrograms/kg), or TNF (6.25 x 10(6) U/kg) that produced minimal changes in liver enzymes. However, when lead was administered simultaneously with either LPS or TNF, serum aspartate transaminase, alanine transaminase, alkaline phosphatase, glutamyl transpeptidase, and plasma triglyceride levels were markedly increased. Lead + LPS treatment increased both peak serum TNF concentrations and TNF "area under the curve" as compared with LPS alone. We conclude that lead not only enhances LPS lethality but also LPS liver injury. Furthermore, lead enhances TNF liver injury and increases LPS-stimulated serum TNF levels. These data suggest that the lead-enhanced LPS model offers a system for studying TNF-induced liver injury.
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PMID:Lead enhances lipopolysaccharide and tumor necrosis factor liver injury. 167 39

To investigate the role of neutrophils (PMNs) and PMN-dependent adhesion molecules in the pathogenesis of liver injury in a model of endotoxin shock, male ICR mice received a dose of 700 mg/kg galactosamine and 100 micrograms/kg Salmonella abortus equi endotoxin. PMNs accumulated continuously in the liver, reaching values of 446 +/- 71 PMNs/50 high-power fields at 9 h (basal value 18 +/- 7). Plasma alanine aminotransferase activities as index of parenchymal cell injury did not change up to 5 h posttreatment (basal value 35 +/- 5 U/l) but increased to 1,950 +/- 460 U/l at 9 h. The formation of glutathione disulfide (GSSG) in plasma as an index of an extracellular oxidant stress also increased only at 9 h. Pretreatment of animals with monoclonal antibodies against the CD11b and CD18 subunits of the CD11/CD18 integrin family on the surface of the PMN reduced the number of PMNs in the liver by 50% and significantly attenuated liver injury and GSSG formation. An anti-CD11a and a nonbinding control antibody were ineffective. It is concluded that PMNs are actively involved in the pathogenesis of galactosamine and endotoxin shock and that at least in part the accumulation of PMNs, the subsequent oxidant stress, and the tissue injury in this model of experimental hepatitis are CD11b/CD18 (Mac-1) dependent.
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PMID:Neutrophil-induced liver cell injury in endotoxin shock is a CD11b/CD18-dependent mechanism. 176 46

We have clearly shown by primary culture of hepatocytes that a promoting factor for proliferation of parenchymal hepatocytes appeared in the portal blood of rats which received 70% partial hepatectomy, and that such a liver-regenerating factor exists not only in murine small-intestinal mucosa, but also in bovine intestinal mucosa at all times. We also observed that in hepatopathy induced in rats by chemical agents such as CCl4 and D-galactosamine, intraperitoneal injection of the bovine small-intestine mucosal extract containing this factor suppressed the increases of GOT, GPT and other enzyme activities in the rats' serum and modified the hepatopathy. These results indicate that the in-vitro effects of these factors on hepatocyte cultures reflect those found in vivo on hepatopathy.
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PMID:Effects of small-intestinal factors on hepatocyte development and modification of chemical agent-induced hepatopathy in rat. 182 14

An artificial liver support procedure based on hemoperfusion via hepatocytes cultured on microcarriers is described. The efficiency of the system was assessed by the survival rate of rats treated with either lethal dosage of 7% CCl4 [30 ml/kg body weight (b.w.)] or D-galactosamine (2.5 g/kg b.w.). In CCl4-treated rats, hemoperfusion via empty microcarriers (n = 16) revealed no surviving animals, whereas the use of the bioartificial liver (n = 11) resulted in 80% (p less than 0.01) and 60% (p less than 0.05) survival 48 and 168 h after hepatotoxin, respectively. For the same time periods, the survival rate in D-galactosamine-intoxicated rats after hemoperfusion with hepatocytes (n = 20) was approximately 60% (p less than 0.05) and was only 5% in those of rats treated with empty microcarriers (n = 20). Sublethal dosage of 7% CCl4 (15 ml/kg b.w.) caused 25% mortality and prolonged (48 h) increase of activity of the liver enzymes and bilirubin levels in the serum of surviving animals. In these rats (n = 8) at the end of 3 h of hemoperfusion via hepatocytes, the bilirubin concentration decreased by 45% as compared with the control group (n = 6) treated with empty microcarriers. Moreover, by 48 h after intoxication, the use of the bioartificial liver resulted in more than a three-fold decrease in glutamate-oxaloacetate transaminase and a 10-fold decrease in glutamate-pyruvate transaminase serum activity as well as a fivefold decline in total and a ninefold decline in conjugated bilirubin levels as compared with the control animals.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bioartificial liver using hepatocytes on biosilon microcarriers: treatment of chemically induced acute hepatic failure in rats. 186 29

An animal model of hepatocytic necrosis was established with injection of D-galactosamine into peritoneal cavity. Examination at regular intervals after injection showed that the level of increased serum TB, ALT and GST and the degree of histological changes in the liver were less marked in PGE-treated animals (n = 34) than those in PGE-untreated animals (n = 29), suggesting that PGE has definite protective effect for experimental hepatocytic necrosis. According to severity of the condition hepatic failure was divided into early stage, typical stage and late stage. A treatment group of 55 cases received PGE1 therapy and a control group basic support therapy only. The results showed that difference of the total effective rate was not significant between the two groups, but in the early stage of hepatic failure, the effective rate in the treatment group was markedly higher than that in the control group. In addition, incidence of hepato-renal syndrome was lower in the treatment group. We are of the opinion that division of severe viral hepatitis into three stages for evaluation of therapeutic effect is rational and useful and early use of PGE1 may show certain efficacy.
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PMID:[Protective effect of prostaglandin E on hepatocytes and its value of early treatment of severe viral hepatitis]. 203 89

Experimental model of acute liver damage with D-galactosamine was made. Thereafter, Salvia miltiorrhiza (SM) and Paeonia lactiflora (PL) were given to the rats. Survival rate of rats and liver coefficient (liver weight/body weight) were observed. Changes of ALT and bilirubin in serum were detected. Level of plasma fibronectin (PFN) was determined at various times. Changes of pathological histology under microscope and electron-microscope were observed. The results showed that SM and PL could increase plasma fibronectin levels in rats, and improve the reticuloendothelial system function and plasma opsonic activity. Aggregation of microaggregated albumin, collagen fragment and immune complexes were markedly reduced. Liver immune damage and microcirculation disorder were avoided. Meanwhile, PFN could cause increase of phagocytosis of Kupffer cell to endotoxin. It is concluded that SM and PL play an important role in protective hepatocyte.
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PMID:[Protective mechanism of Salvia miltiorrhiza and Paeonia lactiflora for experimental liver damage]. 206 49

The present study was conducted to observe the effect of platelet activating factor antagonist-WEB 2086 on the galactosamine/endotoxin (GalN/E)-induced rat liver injury. The results showed that the WEB 2086 (1, 20 or 40 mg/kg, ip) diminished significantly GaIN/E induced elevations of ALT.AST and ACP in the serum (P less than 0.01). Histological changes of the liver were also found to be improved significantly by WEB 2086 administration. Additionally, WEB 2086 decreased significantly the GaIN/E-induced increase of Malondialdehyde (MDA) and Myeloperoxidase (MPO) in the liver (P less than 0.05-0.01), and prevented the decreasing of superoxide dismutase (SOD) in the liver (P less than 0.01). The results obtained with WEB 2086 confirm that platelet activating factor (PAF) has an important role in the pathophysiology of liver injury, PAF-antagonists may have protective effects on liver injury.
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PMID:[Protective effect of a platelet activating factor antagonist in experimental liver injury]. 217 27

Intravenous injection of lipopolysaccharide and D-galactosamine, at doses of 0.2 micrograms/kg and 800 mg/kg, respectively, elicited massive hepatic necrosis within 24 hr in C3H/HeN mice. The plasma L-alanine aminotransferase (ALT, E.C. 2.6.1.2) or L-aspartate aminotransferase (AST, E.C. 2.6.1.1) activities at this point reached more than 2,000 IU/L. However, overt hepatic injury as evaluated by the plasma aminotransferase activities did not develop in mice in which only lipopolysaccharide or only D-galactosamine was injected. No tumor necrosis factor-like activities could be detected in the plasma of galactosamine- and lipopolysaccharide-injected mice as determined by the assay of cytotoxicity to highly tumor necrosis factor-sensitive L-P3 cells through the experimental period of 24 hr. However, passive immunization against mouse tumor necrosis factor-alpha with polyvalent rabbit anti-mouse tumor necrosis factor-alpha antiserum, which was able to neutralize the cytotoxic effects of recombinant mouse tumor necrosis factor-alpha on L-P3 cells, could protect the mice from the development of hepatic injury in a dose-dependent manner. Simultaneous injection of recombinant human tumor necrosis factor-alpha, instead of lipopolysaccharide, with 800 mg/kg of D-galactosamine in lipopolysaccharide-resistant C3H/HeJ mice sensitized the animals more than one thousand-fold to the development of hepatic injury. The livers appeared to be morphologically similar to those of galactosamine- and lipopolysaccharide-injected C3H/HeN mice.
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PMID:Involvement of tumor necrosis factor-alpha in development of hepatic injury in galactosamine-sensitized mice. 222 17


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