Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1) The oxygen consumption increases during Bufo bufo development in accordance with the two steps which border at the "heart beat" stage. 2) Cytochrome c oxidase activity is not proportional to the oxygen consumption: it is notable and constant in the first step, and it only increases in the second. 3) In the mitochondria of preneural embryos, citrate synthase, NADP+ dependent isocitrate dehydrogenase, and succinate dehydrogenase activities are very low in respect to malate dehydrogenase and glutamate oxaloacetate transaminase activities. The Krebs cycle results lowered at the condensing reaction level with acetyl accumulation when pyruvate is available. The same behavior has been observed in the Xenopus laevis oocytes and differentiated tissues. 4) The presence of a phosphagen system which is different from creatine phosphate and arginine phosphate, supporting ATP level, has been demonstrated in B. bufo embryos. 5) Mitochondria of postneural embryos are able to accomplish a complete Krebs cycle by increasing citrate synthase, and succinate dehydrogenase activities. 6) In all B. bufo development, malate dehydrogenase and glutamate oxaloacetate transaminase constitute a multienzymatic system by which the mitochondria accomplish a decarboxylic amino acid shunt required for the transformation of deutoplasm into protoplasm. This shunt is also operative in the X. laevis oocytes. 7) Through pyruvate production, by oxidative decarboxylation of malate, the NAD(P)+ dependent malic enzyme could carry out a fundamental anaplerotic function in the mitochondria which is specialized in the production of biosynthetic blocks belonging to the embryo in which the carbohydrates metabolism rather than the glycolytic activity is designed for pentose phosphate and glycerol phosphate synthesis for protein and cytomembrane production. 8) Consistent metabolic differences have been highlighted between B. bufo embryos and X. laevis embryos.
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PMID:Physiological differentiation of the mitochondria during Bufo bufo development. 1125 8

Refolding of the acid-unfolded precursor to mitochondrial aspartate aminotransferase (pmAAT) is inhibited when cytosolic Hsc70 is included in the refolding reaction (Artigues, A., Iriarte, A., and Martinez-Carrion, M. (1997) J. Biol. Chem. 272, 16852-16861). At low molar excess of Hsc70 pmAAT is recovered in insoluble aggregates containing equal amounts of Hsc70. However, in the presence of a large excess of Hsc70, refolding of pmAAT is still arrested, but the enzyme remains in solution. Similar behavior was observed with two other cytosolic chaperones, bovine Hsp90 and yeast Ydj1. Coimmunoprecipitation of pmAAT using Hsc70 antibodies confirmed the formation of soluble Hsc70-pmAAT complexes at high concentrations of the chaperone. Data from analytical centrifugation, sedimentation in glycerol gradients, and partial purification of the soluble complexes indicate that multiple Hsc70 molecules bind per pmAAT polypeptide chain. The absence of catalytic activity together with the protease susceptibility of pmAAT bound to Hsc70, Hsp90, or Ydj1 suggest that these chaperones bind and maintain pmAAT in a partially unfolded state, analogous to the import-competent conformation of the protein synthesized in cell-free extracts. Remarkably, the purified pmAAT bound to Hsc70 or Ydj1, but not to Hsp90, is imported by isolated mitochondria in a reticulocyte lysate-dependent manner. Thus, both Hsc70 and Ydj1 can trap an import-competent folding intermediate of pmAAT, but productive binding and import into mitochondria require the collaboration of additional cytosolic factors from the lysate.
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PMID:Binding to chaperones allows import of a purified mitochondrial precursor into mitochondria. 1198 13

Activities of enzymes associated with glycerol synthesis were compared in the liver of two osmerid fishes, the smelt (Osmerus mordax), which can accumulate high (400 mM) levels of glycerol and capelin (Mallotus villosus) that does not accumulate glycerol. Animals were sampled at approximately the same time of year and temperature thus negating potential seasonal effects. These species are closely related, reducing interpretative issues involving comparison between unrelated species. We found that key enzyme activities were elevated in the smelt relative to the non-glycerol accumulating capelin, namely enzymes involved with glycolysis (phosphofructose kinase-1 and aldolase), amino acid metabolism (aspartate aminotransferase and alanine aminotransferase), gluconeogenesis (phosphoenolpyruvate carboxykinase) and glycerol synthesis (glycerol-3-phosphate dehydrogenase). The enzyme profiles strongly support the hypothesis that smelt can synthesize glycerol by utilizing glycogen and amino acids as the carbon source and that they have increased capacity for metabolic flux through loci required for synthesis of the three carbon intermediate dihydroxyacetone phosphate and subsequently glycerol synthesis.
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PMID:Comparison of liver enzymes in osmerid fishes: key differences between a glycerol accumulating species, rainbow smelt (Osmerus mordax), and a species that does not accumulate glycerol, capelin (Mallotus villosus). 1202 Jun 59

1,2,3-Trichloropropane is a colorless liquid used as a paint and varnish remover, solvent, and degreasing agent, and as a crosslinking agent in the synthesis of polysulfides and hexafluoropropylene. 1,2,3-Trichloropropane may be found as an impurity in certain nematocides and soil fumigants and as a contaminant of drinking and ground water. Studies on the toxic and carcinogenic effects of 1,2,3-trichloropropane were initiated because of the close structural relationship of this chemical to other short-chain halogenated compounds that were demonstrated to be carcinogenic in experimental animals, and because of the potential for human exposure. Toxicology and carcinogenicity studies were conducted by administering 1,2,3-trichloropropane (greater than 99% pure) in corn oil by gavage to groups of F344/N rats and B6C3FI mice for 17 weeks and 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium strains, mouse lymphoma cells, and Chinese hamster ovary cells. 17-Week Studies: Groups of 20 male and 20 female rats received 1,2,3-trichloropropane in corn oil by gavage at doses of 8, 16, 32, 63, 125, or 250 mg/kg body weight 5 days per week for up to 17 weeks; 30 male and 30 female rats received corn oil alone and served as controls. Animals were evaluated at 8 or 17 weeks. All rats in the 250 mg/kg groups died by week 5. One male and four female rats in the 125 mg/kg groups died during the study. The mean body weight gains and final mean body weights of males receiving 63 mg/kg and of males and females receiving 125 mg/kg were lower than those of the controls. Hematocrit values, hemoglobin concentrations, and erythrocyte counts decreased with dose in males and females. Serum alanine aminotransferase, aspartate aminotransferase, and sorbitol dehydrogenase activities were significantly increased in some female rats receiving 125 mg/kg. Serum pseudocholinesterase activity decreased with dose in females. Increases in kidney and liver weights were related to chemical administration. The principal toxic lesions associated with the administration of 1,2,3-trichloropropane to rats were hepatocellular necrosis, karyomegaly, and biliary hyperplasia of the liver; renal tubule necrosis, regeneration, and karyomegaly of the kidney; and necrosis and inflammation of the nasal olfactory and respiratory epithelium. Groups of 20 male and 20 female mice received 1,2,3-trichloropropane in corn oil by gavage at doses of 8, 16, 32, 63, 125, or 250 mg/kg 5 days per week for up to 17 weeks; 30 male and 30 female mice received corn oil alone and served as controls. Sixteen male and seven female mice in the 250 mg/kg groups died by week 4. The final mean body weights and mean body weight gains of dosed mice were similar to those of the controls, except those of 250 mg/kg males, which were lower than those of controls. The principal toxic lesions associated with the administration of 1,2,3-trichloropropane were hepatocellular necrosis and karyomegaly of the liver; necrosis, regeneration, and hyperplasia of the bronchiolar epithelium in the lung; and acanthosis (hyperplasia) and hyperkeratosis of the forestomach epithelium. 2-Year Studies: Groups of 60 male and 60 female rats received 0, 3, 10, or 30 mg 1,2,3-trichloropropane/kg body weight in corn oil by gavage 5 days per week for up to 104 weeks. Selection of 30 mg/kg as the high dose in these studies was based on the following chemical-related effects in the 17-week studies: deaths and liver and kidney lesions at 125 and 250 mg/kg and reduced final mean body weights and mean body weight gains at 63 mg/kg or greater. Groups of 60 male and 60 female mice received 0, 6, 20, or 60 mg 1,2,3-trichloropropane/kg body weight in corn oil by gavage 5 days per week for up to 104 weeks. Selection of 60 mg/kg as the high dose was based on chemical-related deaths and lesions of the liver, lung, and forestomach at 125 and 250 mg/kg in the 17-week studies. 15-Month Interim Evaluations: Up to 10 rats and 10 mice from each dose group were evaluated at 15 months. Absolute and relative liver and kidned kidney weights of dosed rats were significantly greater than those of the controls. Chemical-related nonneoplastic lesions and neoplasms of the forestomach, oral mucosa, pancreas (males), kidney, mammary gland (females), preputial gland, and clitoral gland were observed in dosed rats. Chemical-related nonneoplastic lesions and neoplasms of the forestomach and liver (females) were observed in dosed mice. Survival and Body Weight in the 2-Year Studies: Survival of male and female rats receiving 10 or 30 mg/kg 1,2,3-trichloropropane was significantly lower than that of controls. Two-year survival rates of male rats were: control, 34/50; 3 mg/kg, 32/50; 10 mg/kg, 14/49; 30 mg/kg, 0/52; and of females were: 31/50, 30/49, 8/52, 0/52. At 30 mg/kg, survival was markedly reduced due to chemical-related neoplasms, and survivors were killed in weeks 67 (females) or 77 (males). Final mean body weights of 30 mg/kg rats were 13% lower for males and 12% lower for females than those of controls; mean body weights of 3 and 10 mg/kg rats were similar to controls. Survival rates of mice receiving 6, 20, or 60 mg/kg 1,2,3-trichloropropane were also significantly lower than those of controls. Two-year survival rates of male mice were: 42/52, 18/51, 0/54, 0/56; and of female mice were: 41/50, 13/50, 0/51, 0/55. Because of reduced survival at 20 and 60 mg/kg due to chemical-related neoplasms, survivors were killed in weeks 73 (60 mg/kg females), 79 (60 mg/kg males), or 89 (20 mg/kg males and females). Final mean body weights were 16% lower for 60 mg/kg males, 18~ lower for 60 mg/kg females, and 13% lower for 20 mg/kg males than those of controls. Final mean body weights of 6 mg/kg males and females and 20 mg/kg females were similar to controls. Neoplasms and Nonneoplastic Lesions in the 2-Year Studies: Administration of 1,2,3-trichloropropane to rats induced benign and malignant neoplasms of the oral mucosa (pharynx and tongue), forestomach, and preputial and clitoral glands in males and females; benign neoplasms of the exocrine pancreas and kidney in males, and malignant neoplasms of the mammary gland in females. The incidences of squamous cell papillomas and carcinomas of the oral mucosa were significantly increased in 10 and 30 mg/kg rats, while the incidences of squamous cell papillomas or carcinomas (combined) of the forestomach were significantly increased in all dosed groups. The incidence of pancreatic acinar adenoma was significantly increased in dosed males, but not in dosed females. Similarly, the incidence of adenoma of the kidney was significantly increased in 10 and 30 mg/kg male rats only. The incidences of adenoma or carcinoma (combined) of the preputial gland in 30 mg/kg males and of the clitoral gland in 10 and 30 mg/kg females (homologous organs) were significantly increased. The incidence of adenocarcinoma of the mammary gland was significantly increased in the 10 and 30 mg/kg females. The incidences of Zymbal's gland carcinomas were increased in 30 mg/kg males and females. Adenocarcinomas of the intestine occurred in small numbers of dosed rats and may have been chemical related. In mice, the incidence of squamous cell carcinoma of the oral mucosa was significantly increased only in 60 mg/kg females. In contrast, the incidences of squamous cell papilloma and carcinoma of the forestomach were significantly increased in all groups of dosed mice. The incidences of hepatocellular adenoma or carcinoma (combined) were significantly increased in all dosed groups of males and 60 mg/kg females. The incidences of harderian gland adenoma were significantly increased in 20 mg/kg males and in 60 mg/kg males and females. The incidences of uterine adenoma, adenocarcinoma, and stromal polyp were significantly increased in 60 mg/kg females. Genetic Toxicology: 1,2,3-Trichloropropane was mutagenic in vitro in the presence of S9 metabolic activation. At two laboratories, positive responses were obtained for mutagenicity in Salmonella typhimurium strains TA97, TA98, TA100, and TA1535 in the presence of S9; no mutagenic activity was observed in TA1537, with or without S9. 1,2,3-Trichloropropane induced trifluorothymidine resistance in L5178Y mouse lymphoma cells with, but not without, S9. In cultured Chinese hamster ovary cells, sister chromatid exchanges and chromosomal aberrations were induced by 1,2,3-trichloropropane; however, significant increases in the endpoints of both cytogenetic effects occurred only in the presence of S9. Conclusions: Under the conditions of these 2-year gavage studies, there was clear evidence of carcinogenic activity of 1,2,3-trichloropropane in male F344/N rats based on increased incidences of squamous cell papillomas and carcinomas of the oral mucosa and forestomach, adenomas of the pancreas and kidney, adenomas or carcinomas of the preputial gland, and carcinomas of the Zymbal's gland. Adenomatous polyps and adenocarcinomas of the intestine may have been related to chemical administration. There was clear evidence of carcinogenic activity of 1,2,3-trichloropropane in female F344/N rats based on increased incidences of squamous cell papillomas and carcinomas of the oral mucosa and forestomach, adenomas or carcinomas of the clitoral gland, adenocarcinomas of the mammary gland, and carcinomas of the Zymbal's gland. Adenocarcinomas of the intestine may have been related to chemical administration. There was clear evidence of carcinogenic activity of 1,2,3-trichloropropane in male B6C3F1 mice based on increased incidences of squamous cell papillomas and carcinomas of the forestomach, hepatocellular adenomas or carcinomas of the liver, and harderian gland adenomas. Squamous cell papillomas of the oral mucosa may have been related to chemical administration. There was clear evidence of carcinogenic activity of 1,2,3-trichloropropane in female B6C3F1, mice based on increased incidences of squamous cell carcinomas of the oral mucosa, squamous cell papillomas and carcinomas of the forestomach, hepatocellular adenomas or carcinomas of the liver, harderian gland adenomas, and uterine adenomas, adenocarcinomas, and stromal polyps. Nonneoplastic lesions associated with exposure to 1,2,3-trichloropropane included increased severity of nephropathy in male rats and increased incidences of basal cell and squamous hyperplasia of the forestomach, acinar hyperplasia of the pancreas, renal tubule hyperplasia, and preputial or clitoral gland hyperplasia in male and female rats. Increased incidences of squamous hyperplasia of the forestomach and eosinophilic foci in the liver in male and female mice were chemical related. Synonyms: Allyl trichloride, glycerol tnchlorohydrin, glyceryl tnchlorohydrin, trichlorohydrin
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PMID:NTP Toxicology and Carcinogenesis of 1,2,3-Trichloropropane (CAS No. 96-18-4) in F344/N Rats and B6C3F1 Mice (Gavage Studies). 1269 52

This study investigated the physiological adaptations to fasting using the farmed blue fox (Alopex lagopus) as a model for the endangered wild arctic fox. Sixteen blue foxes were fed throughout the winter and 32 blue foxes were fasted for 22 d in Nov-Dec 2002. Half of the fasted blue foxes were food-deprived again for 22 d in Jan-Feb 2003. The farmed blue fox lost weight at a slower rate (0.97-1.02% body mass d(-1)) than observed previously in the arctic fox, possibly due to its higher initial body fat content. The animals experienced occasional fasting-induced hypoglycaemia, but their locomotor activity was not affected. The plasma triacylglycerol and glycerol concentrations were elevated during phase II of fasting indicating stimulated lipolysis, probably induced by the high growth hormone concentrations. The total cholesterol, HDL- and LDL-cholesterol, urea, uric acid and total protein levels and the urea:creatinine ratio decreased during fasting. Although the plasma levels of some essential amino acids increased, the blue foxes did not enter phase III of starvation characterized by stimulated proteolysis during either of the 22-d fasting procedures. Instead of excessive protein catabolism, it is liver dysfunction, indicated by the increased plasma bilirubin levels and alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase activities, that may limit the duration of fasting in the species.
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PMID:Physiological adaptations to fasting in an actively wintering canid, the Arctic blue fox (Alopex lagopus). 1635 68

Semen samples from 12 bucks Were extended with 10 different extenders containing glycerol, DMSO, glycerol + DMSO, and glycerol + lactose in varying concentrations as cryoprotective agents. The activities of acrosin, hyaluronidase, alkaline phosphatase (AKP), aspartate aminotransferase (AST), alanine amino transferase (ALT) and lactic dehydrogenase (LDH) were assayed in equilibrated (Prefreeze) and frozen thawed (Postfreeze) semen samples. Significantly (P < 0.01) higher intracellular activity of acrosin was recorded in semen samples extended with lactose than with the other extenders, with the maximum being with Tris yolk glycerol lactose (TYGL(180)). Effects of extenders on acrosin activity were significant (P < 0.01) at both of the pre-and postfreeze stages. However, extracellular activities of hyaluronidase, alkaline phosphatase, transaminases (AST and ALT), and lactic dehydrogenase were significantly higher in extenders containing DMSO than lactose. Leakage of these enzymes was found to increase from the prefreeze to the post freeze stage.
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PMID:Effect of cryoprotectants on release of various enzymes from buck spermatozoa during freezing. 1672 4

Casein-based diets containing a low (LDI) or high (HDI) dose of soya protein concentrate enriched with isoflavones were fed to obese Zucker rats for 6 weeks. HDI feeding, but not LDI feeding, reduced the fatty liver and decreased the plasma levels of alanine transaminase and aspartate transaminase. This was accompanied by increased activities of mitochondrial and peroxisomal beta-oxidation, acetyl-CoA carboxylase, fatty acid synthase and glycerol-3-phosphate acyltransferase in liver and increased triacylglycerol level in plasma. The decreased fatty liver and the increased plasma triacylglycerol level appeared not to be caused by an increased secretion of VLDL, as HDI decreased the hepatic mRNA levels of apo B and arylacetamide deacetylase. However, the gene expression of VLDL receptor was markedly decreased in liver, but unchanged in epididymal white adipose tissue and skeletal muscle of rats fed HDI, indicating that the liver may be the key organ for the reduced clearance of triacylglycerol-rich lipoproteins from plasma after HDI feeding. The n-3/n-6, 20:4n-6/18:2n-6 and (20:5n-3+22:6n-3)/18:3n-3 ratios were increased in liver triacylglycerol by HDI. The phospholipids in liver of rats fed HDI contained a low level of 20:4n-6 and a high level of 20:5n-3, favouring the production of anti-inflammatory eicosanoids. When obese Zucker rats were fed soya protein, this also resulted in reduced fatty liver, possibly through reduced clearance of VLDL by the liver. We conclude that the isoflavone-enriched soya concentrate as well as soya protein may be promising dietary supplements for treatment of non-alcoholic fatty liver.
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PMID:Dietary soya protein concentrate enriched with isoflavones reduced fatty liver, increased hepatic fatty acid oxidation and decreased the hepatic mRNA level of VLDL receptor in obese Zucker rats. 1692 18

The objective of the present study was to compare changes of blood parameters induced by the same work and performed in the same conditions in two racehorse breeds, Thoroughbred and Purebred Arabian. The effect of moderate-intensity exercise was studied in 20 stallions--ten Thoroughbreds, aged 2-3 years and the same number of Purebred Arabians, 3-4 years old. All the horses were administrated the same effort test consisting in 1200 m gallop at a speed typical of the daily training sessions. Three jugular venous blood samples were collected for each horse: at rest, just after the end of the gallop and after 30-minute rest. In the gathered blood, a hemoglobin (Hb) concentration was determined as well as plasma level of glucose (Glc), triacylglycerols (TG), glycerol, free fatty acids (FFA), total plasma proteins (TP) and the activity of creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST). In the Arabian horses, an increase in levels of TP, glycerol, FFA and CK activity measured just after exercise was higher than that in Thoroughbreds. Similarly, after a 30-minute rest, a post-exercise rise of TP, AST, glycerol and FFA proved to be higher in the Arabian horses compared to that in the Thoroughbreds. Only TG plasma concentration measured 30 minutes following the effort was significantly lower in the Arabian horses than in Thoroughbreds. It can be concluded that the Thoroughbred horses adapted better to the effort test applied in this study as compared to the Purebred Arabian horses. The parameters related to lipid metabolism proved to be the most sensitive indicators of breed differences in relation to moderate-intensity exercise.
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PMID:Comparison of plasma biochemical parameters in Thoroughbred and Purebred Arabian horses during the same-intensity exercise. 1720 41

We show that cytosolic aspartate aminotransferase (cAspAT) is involved in adipocyte glyceroneogenesis, a regulated pathway that controls fatty acid homeostasis by promoting glycerol 3-phosphate formation for fatty acid re-esterification during fasting. cAspAT activity, as well as the incorporation of [(14)C]aspartate into the neutral lipid fraction of 3T3-F442A adipocytes was stimulated by the thiazolidinedione (TZD) rosiglitazone. Conversely, the ratio of fatty acid to glycerol released into the medium decreased. Regulation of cAspAT gene expression was specific to differentiated adipocytes and did not require any peroxisome proliferator-activated receptor gamma (PPARgamma)/retinoid X receptor-alpha direct binding. Nevertheless, PPARgamma is indirectly necessary for both cAspAT basal expression and TZD responsiveness because they are, respectively, diminished and abolished by ectopic overexpression of a dominant negative PPARgamma. The cAspAT TZD-responsive site was restricted to a single AGGACA hexanucleotide located at -381 to -376 bp whose mutation impaired the specific RORalpha binding. RORalpha ectopic expression activated the cAspAT gene transcription in absence of rosiglitazone, and its protein amount in nuclear extracts is 1.8-fold increased by rosiglitazone treatment of adipocytes. Finally, the amounts of RORalpha and cAspAT mRNAs were similarly increased by TZD treatment of human adipose tissue explants, confirming coordinated regulation. Our data identify cAspAT as a new member of glyceroneogenesis, transcriptionally regulated by TZD via the control of RORalpha expression by PPARgamma in adipocytes.
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PMID:Cytosolic aspartate aminotransferase, a new partner in adipocyte glyceroneogenesis and an atypical target of thiazolidinedione. 1754 71

Clinical studies suggest that moderate alcohol consumption can have beneficial effects, in particular regarding cardiovascular events, insulin resistance, and type 2 diabetes. In this study, lean and obese diabetic ob/ob mice were submitted or not to chronic ethanol intake via the drinking water for 6 months, which was associated with moderate levels of plasma ethanol. Plasma levels of alanine aminotransferase and aspartate aminotransferase were not increased by alcohol intake. Ethanol consumption progressively reduced the gain of body weight in ob/ob mice, but not in lean mice, and this was observed despite higher calorie intake. Increased plasma free fatty acids and glycerol in ethanol-treated ob/ob mice suggested peripheral lipolysis. Glycemia and insulinemia were significantly reduced, whereas adiponectinemia was increased in ethanol-treated ob/ob mice. Liver weight and triglycerides were significantly decreased in ethanol-treated ob/ob mice, and this was associated with less microvesicular steatosis. Hepatic levels of AMP-activated protein kinase and the phosphorylated form of acetyl-CoA carboxylase were higher in ethanol-treated ob/ob mice, suggesting better fatty acid oxidation. However, hepatic mRNA expression of several lipogenic genes was not reduced by ethanol consumption. Finally, mild oxidative stress was noticed in the liver of ethanol-treated mice, regardless of their genotype. Hence, our data are in keeping with clinical studies suggesting that moderate ethanol intake can have beneficial effects on type 2 diabetes and insulin sensitivity, at least in part through increased levels of plasma adiponectin. However, further studies are needed to determine whether long-term drinking of light-to-moderate amounts of ethanol is safe for the liver.
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PMID:Chronic ethanol consumption lessens the gain of body weight, liver triglycerides, and diabetes in obese ob/ob mice. 1958 15


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