Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The 3-years efficacy and safety of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor simvastatin (S) (previously called synvinolin or MK-733) has been studied in single and combined therapy with cholestyramine (C) in 48 hypercholesterolaemic patients. Plasma lipids, lipoproteins and apolipoproteins A-I and B, and blood safety tests (haematology, liver function, creatine phosphokinase (CPK), creatinine, blood glucose and thyroid function) were determined regularly throughout the study. Extensive ophthalmological examinations with particular focus on the lens were done before initiation of therapy and at every 6 months during drug treatment. Maximal reductions of mean plasma total cholesterol concentration (34% with S; 47% with S + C) and low-density lipoprotein (LDL)-cholesterol concentration (42% with S; 56% with S + C) were achieved after 4 weeks on full-dose therapy. During continued treatment, years 1 through 3, the reduction of mean plasma total cholesterol was 26-29% with S alone, and 31-41% with S + C. Significant reductions of plasma triglycerides (15-27%) and very low density lipoprotein (VLDL) triglycerides (10-27%) were achieved in the group treated with S as single therapy. In this group there was also a significant increase (10-14%) of high-density lipoprotein (HDL)-cholesterol. In liver aspartate (AST) and alanine (ALT) aminotransferases, as well as alkaline phosphatase (ALP), minor and variable, but usually transient, increases were seen. Repeated ophthalmological examinations did not demonstrate any drug-related side effects. It is concluded that simvastatin is a safe and efficient cholesterol-lowering drug for long-term therapy, both as a single drug and in combination with cholestyramine.
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PMID:Long-term efficacy and safety of simvastatin alone and in combination therapy in treatment of hypercholesterolaemia. 178 13

The effects of sesamin, a lignan from sesame oil, on various aspects of cholesterol metabolism were examined in rats maintained on various dietary regimens. When given at a dietary level of 0.5% for 4 weeks, sesamin reduced the concentration of serum and liver cholesterol significantly irrespective of the presence or absence of cholesterol in the diet, except for one experiment in which the purified diet free of cholesterol was given. On feeding sesamin, there was a decrease in lymphatic absorption of cholesterol accompanying an increase in fecal excretion of neutral, but not acidic, steroids, particularly when the cholesterol-enriched diet was given. Sesamin inhibited micellar solubility of cholesterol, but not bile acids, whereas it neither bound taurocholate nor affected the absorption of fatty acids. Only a marginal proportion (ca. 0.15%) of sesamin administered intragastrically was recovered in the lymph. There was a significant reduction in the activity of liver microsomal 3-hydroxy-3-methylglutaryl coenzyme A reductase after feeding sesamin, although the activity of hepatic cholesterol 7 alpha-hydroxylase, drug metabolizing enzymes, and alcohol dehydrogenase remained uninfluenced. Although the weight and phospholipid concentration of the liver increased unequivocally on feeding sesamin, the histological examination by microscopy showed no abnormality, and the activity of serum GOT and GPT remained unchanged. Since sesamin lowered both serum and liver cholesterol levels by inhibiting absorption and synthesis of cholesterol simultaneously, it deserves further study as a possible hypocholesterolemic agent of natural origin.
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PMID:Inhibition of cholesterol absorption and synthesis in rats by sesamin. 185 8

Simvastatin is a potent competitive inhibitor of the 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) which is the rate-limiting enzyme of cholesterol synthesis. In guinea-pigs, administration of a high oral dose of simvastatin (125 mg/kg/day at the beginning of the study) during 18 days had a major hepatotoxic effect whereas a lower oral dose (30 mg/kg/day) did not seem to cause any liver damage. A significant reduction in microsomal Cyt P 450 content was only observed on a high dose of simvastatin whereas HMG CoA reductase activity was reduced in the group with the low simvastatin dose. The hepatic microsomal aminopyrine N-demethylase activity remained unchanged in all groups. The liver lesion was hepatocellular necrosis accompanied in some animals by a biliary duct proliferation. It was associated with a 10-fold elevation in serum aspartate and alanine aminotransferase activities, as well as a great reduction in daily food intake and body weight (28%). The hepatotoxicity of simvastatin could result from the low basal content of HMG-CoA reductase in guinea-pig liver, the prolonged inhibition of mevalonate synthesis and probably, from the absence of HMG-CoA reductase enzyme de novo synthesis.
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PMID:Biochemical changes and morphological alterations of the liver in guinea-pigs after administration of simvastatin (HMG CoA reductase-inhibitor). 207 27

The efficacy and safety of 20 mg simvastatin (a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor) and of 16 g cholestyramine daily in the treatment of 34 hypercholesterolaemic patients have been compared after dietary treatment and stratified randomization. The effect of combined treatment with the two drugs was studied in 5 patients with severe hypercholesterolaemia. After 6 weeks of treatment the simvastatin group showed a significantly greater (p less than 0.05) decrease in the mean total plasma cholesterol concentration from 7.88 to 5.48 mmol/l than in the cholestyramine group in whom there was a fall from 7.82 to 6.73 mmol/l. Simvastatin decreased the mean plasma LDL cholesterol concentration from 6.07 to 3.76 mml/l and cholestyramine decreased it from 6.16 to 4.46 mmol/l. Simvastatin also reduced the mean plasma total triglycerides by 24%, VLDL triglycerides by 20% and VLDL cholesterol by 36%, while cholestyramine led to increases in these parameters by 64%, 85% and 63%, respectively. Mean plasma HDL cholesterol concentration and the subfractions HDL2 and HDL3 cholesterol were significantly increased by simvastatin. Simvastatin and cholestyramine reduced the mean plasma apolipoprotein B concentration by 28% and 13%, respectively. The mean plasma apolipoprotein A-I concentration was significantly higher only on simvastatin treatment. Simvastatin did not cause any subjective or objective side effects, while cholestyramine caused gastrointestinal problems in 31% of patients. Small increases in serum alanine aminotransferase (S-ALT) activity were seen with both drugs. Cholestyramine significantly raised the serum alkaline phosphatase (S-ALP) although to a level still within the normal range. It is concluded that 20 mg simvastatin was more effective than 16 g cholestyramine in the treatment of hypercholesterolaemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparative effects of simvastatin and cholestyramine in treatment of patients with hypercholesterolaemia. 250 17

The effects of synvinolin (MK-733), a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, were investigated in 43 patients with heterozygous familial hypercholesterolaemia in a double-blind, placebo-controlled, dose-finding study. Synvinolin was given in doses ranging from 2.5 mg to 80 mg per day for 4 weeks. 8 patients received placebo. Low-density-lipoprotein cholesterol fell on average by 18% on 2.5 mg/day and 42% on 80 mg/day. The drug was as effective whether it was given once or twice daily. Serum high-density-lipoprotein cholesterol tended to increase and serum triglycerides to decrease on the higher doses. The drug was tolerated well. Except for a slight rise in alanine aminotransferase in 3 patients no objective side-effects were observed.
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PMID:Effects of synvinolin (MK-733) on plasma lipids in familial hypercholesterolaemia. 287 29

We performed a multicenter, open-label study to determine the long-term safety and efficacy of a new extended-release once-a-night niacin preparation, Niaspan, in the treatment of hypercholesterolemia. Niaspan, 0.5 to 3.0 g once a night at bedtime, was used alone or in combination with a statin (inhibitor of hydroxymethylglutaryl coenzyme A reductase), a bile acid sequestrant, or both. Patients included 269 hypercholesterolemic male and female adults enrolled in a 96-week study, and 230 additional adults for whom short-term safety data were available. The dosages of Niaspan attained by 269 patients were 1,000 mg (95% of patients), 1,500 mg (86%), and 2,000 mg (65%). After 48 weeks of treatment, Niaspan alone (median dose 2,000 mg) reduced low-density lipaprotein (LDL) cholesterol (18%), apolipoprotein B (15%), total cholesterol (11%), triglycerides (24%), and lipoprotein(a) (36%), and increased high-density lipoprotein (HDL) cholesterol (29%). Niaspan plus a statin lowered LDL cholesterol (32%), apolipoprotein B (26%), total cholesterol (23%), triglycerides (30%), and lipoprotein(a) (19%), and increased HDL cholesterol (26%). Reversible elevations of aspartate aminotransferase or alanine aminotransferase more than twice the normal range occurred in 2.6% of patients. One patient discontinued Niaspan because of transaminase elevations. Intolerance to flushing, leading to discontinuation of Niaspan, occurred in 4.8% of patients. The overall rate of discontinuance due to flushing in this study combined with 2 previous randomized trials was 7.3%. In the long-term treatment of hypercholesterolemia, Niaspan produced favorable changes in LDL and HDL cholesterol, triglycerides, and lipoprotein(a). Adverse hepatic effects were minor and occurred at rates similar to those reported for statin therapy.
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PMID:Effectiveness of once-nightly dosing of extended-release niacin alone and in combination for hypercholesterolemia. 976 Oct 83

Ten years' experience of treatment with the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor simvastatin in 45 hypercholesterolemic high-risk patients is reported. All patients started with 20 mg simvastatin/day. The simvastatin dose was increased to 40 mg in 22 patients. Fourteen patients needed further addition of cholestyramine. Simvastatin reduced plasma cholesterol by 33% after 1 month and was further reduced after adjustment of the lipid-lowering treatment. The mean reduction in plasma cholesterol varied between 30% and 35% in 2 to 10 years. Low-density lipoprotein cholesterol demonstrated mean reductions of 34% to 42%. Mean plasma triglycerides were reduced by 26% after 1 month and by 1% to 19% the following years. High-density lipoprotein (HDL) cholesterol increased initially by 8% and remained elevated at 7% to 11% during the first 6 years, but then dropped slightly below baseline. HDL2 cholesterol increased by 9% to 25% the first 6 years and then decreased. HDL3 cholesterol showed a persistent elevation during simvastatin treatment. About half of the subjects had minor transient but clinical insignificant increases in creatine kinase. No cases of myopathy were seen. Mean serum aspartate aminotransferase and alanine aminotransferase increased significantly but within the normal ranges during the 10 years. The tolerability and compliance of simvastatin treatment was excellent as judged from patients' reports and from analyses of low-density lipoprotein cholesterol. This 10-year study demonstrates that simvastatin is an effective and safe drug with excellent tolerability with only few minor side effects, and causes a pronounced and persistent cholesterol-lowering effect during long-term treatment of hypercholesterolemic patients at risk.
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PMID:Efficacy and safety of simvastatin for high-risk hypercholesterolemia. 1019 May 17

The chronic toxicity of atorvastatin (AT), an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, was evaluated in beagle dogs. Dogs were treated with 0, 10, 40, or 120 mg/kg of AT daily. Treatment lengths were 52 wk, 52 wk followed by 12 wk without drug, or 104 wk. Decreases in cholesterol levels were dose related and stable throughout the treatment period. Increases in alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase were transient and dose related in severity at > or = 40 mg/kg. Two dogs administered 120 mg/kg of AT daily were sacrificed moribund during the first 9 wk of treatment. Hepatic lesions were reversible with or without continued treatment and dose related in severity and distribution. Hepatic microgranulomas and hepatocellular degeneration were seen at the 120-mg/kg dose in dogs sacrificed before 53 wk. Before 53 wk, hepatocellular lipofuscin deposits were increased in dogs given > or = 40 mg/kg of AT daily but were similar to controls after 12 wk without drug and after 104 wk of continuous treatment. Bile stasis occurred in dogs given > or = 40 mg/kg of AT daily at all time points but was less severe after reversal and at week 104 compared with week 52.
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PMID:Hepatic effects in beagle dogs administered atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, for 2 years. 1048 19

Squalene synthase (SQS; EC 2.5.1.21) plays an important role in the cholesterol biosynthetic pathway. We discovered ER-28448, 5-(N-[2-butenyl-3-(2-methoxyphenyl)]-N-methylamino)-1, 1-penthylidenebis(phosphonic acid) trisodium salt, as a potent and selective inhibitor of SQS. ER-28448 inhibited SQS in rat liver microsome with an IC(50) value of 3.6 nm. We also prepared ER-27856, the tripivaloyloxymethyl ester prodrug of ER-28448. Although less active than ER-28448 in a liver microsome assay, ER-27856 more potently inhibited cholesterol biosynthesis in rat hepatocytes; and ER-27856 orally inhibited de novo cholesterol biosynthesis in Sprague-Dawley rats, with an ED(50) value of 1.6 mg/kg. In HepG2 cells, ER-27856 upregulated low density lipoprotein receptor activity to 2.1 times that of control. A time-course study indicated that the inhibitory effect of ER-27856 on cholesterol biosynthesis in rats continued for up to 8 h. In a study of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (HMGRIs), atorvastatin actively suppressed cholesterol biosynthesis for 8 h, whereas the effect of pravastatin and simvastatin diminished at 4 and 8 h, respectively. In rhesus monkeys, 4 days of oral administration of ER-27856 lowered plasma total cholesterol (TCHO) more potently than did these HMGRIs. Whereas atorvastatin significantly elevated plasma alanine aminotransferase, a marker of hepatotoxicity, to 3.7 times at 100 mg/kg, ER-27856 increased the level only 1.4 times at 10 mg/kg, at which doses the hypocholesterolemic effect was equivalent. During 28 days of administration, ER-27856 reduced TCHO and non-high density lipoprotein (non-HDL) cholesterol by 72 and 95%, respectively. These results demonstrate that ER-27856 had more potent hypocholesterolemic activity and less hepatotoxic effect than HMGRIs. ER-27856 may contribute to the treatment of hypercholesterolemic patients.
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PMID:Effect of ER-27856, a novel squalene synthase inhibitor, on plasma cholesterol in rhesus monkeys: comparison with 3-hydroxy-3-methylglutaryl-coa reductase inhibitors. 1088 96

Fluvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, and its metabolites have been reported to protect against oxidative DNA damage in vitro. Streptozotocin (STZ) has drawn attention as a potential source of oxidative stress that induces genotoxicity. In order to elucidate the antioxidative effects of fluvastatin in vivo, we investigated the effects of 7-day treatment with fluvastatin on DNA damage in STZ-treated mice, as well as the effects of the main fluvastatin metabolites (M2, M3 and M4) and other inhibitors of the same enzyme, pravastatin and simvastatin. Protective effects against DNA damage in the liver and kidney from STZ-treated mice were assessed by the single-cell gel electrophoresis assay, and by detecting 8-hydroxy-2'-deoxyguanosine. A single intraperitoneal injection of STZ (150 mg/kg) increased serum levels of glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and blood urea nitrogen (BUN), and also caused DNA damage in the liver and kidney. Fluvastatin and its metabolites prevented the STZ-induced elevation of DNA damage and inhibited the increase in serum levels of AST, ALT and BUN. Fluvastatin and its metabolites showed protective effects against DNA damage as potent as that of the reference antioxidants (ascorbic acid, trolox and probucol) though pravastatin and simvastatin still lacked protective activity. Fluvastatin protected the mice against STZ-induced DNA damage, and may reduce the risk of oxidative stress in vivo.
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PMID:Antioxidative effects of fluvastatin and its metabolites against DNA damage in streptozotocin-treated mice. 1238 3


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