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)

The effect of variable doses of ethanol on plasma lecithin: cholesterol acyltransferase (LCAT) activity was examined in male, atherosclerosis-susceptible squirrel monkeys over a 12-month period. Primates were divided into three groups: 1) Controls fed isocaloric liquid diet; 2) Low Ethanol monkeys given liquid diet with vodka substituted isocalorically for carbohydrate at 12% of calories; and 3) High Ethanol animals fed diet plus vodka at 24% of calories. There were no significant differences between the treatments in serum glutamate oxaloacetate transaminase (SGOT), a measure of liver function. However, plasma LCAT activity (% esterification/min) measured in vitro was significantly reduced in High Ethanol monkeys while cholesterol esterification was elevated in the Low Ethanol group and intermediate in Controls. Similarly, the in vivo appearance of radiolabeled cholesteryl ester in high density lipoproteins (HDL) following the intravenous injection of 3H mevalonolactone was highest in the Low Ethanol primates, intermediate in Controls and significantly lower in monkeys fed the high alcohol diet. In vitro measurement of LCAT enzyme efficiency was similar for the three groups while substrate efficiency was lower in the High Ethanol treatment. Although LCAT activator (apoprotein A-I) was not markedly altered by dietary ethanol and the concentration of LCAT substrates (HDL free cholesterol and phosphatidyl choline) was significantly elevated in the High Ethanol group, subtle modifications in substrate-product composition may account for the observed reduction in cholesterol esterification. These include potential substrate and/or product LCAT inhibition resulting from increased concentrations of plasma free cholesterol, HDL lysophosphatidyl choline, and higher HDL2/HDL3 subfraction ratios, as well as alterations in HDL phospholipid fatty acid profiles in the High Ethanol group. Results from this study provide the first evidence of an anomalous enhancement in LCAT activity in nonhuman primates fed ethanol at 12% of calories and a marked depression in cholesterol esterification at the 24% dose which may be due to substrate alterations and product inhibition prior to overt biochemical evidence of liver dysfunction.
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PMID:Effect of ethanol on lecithin:cholesterol acyltransferase (LCAT) activity. 399 6

Immediate-release niacin manifests beneficial effects in cardiovascular disease with respect to dyslipidemic states. It lowers low-density lipoprotein (LDL) cholesterol, triglycerides, lipoprotein(a), and apoprotein B; at the same time, it increases high-density lipoprotein (HDL) cholesterol, HDL2, and apoprotein A-I. However, use of crystalline niacin has drawbacks: therapy requires multidose regimens, and side effects include flushing and pruritus. Slowing absorption with sustained-release formulations succeeds in decreasing flushing and increasing tolerance, but increases in hepatic enzyme levels have raised safety concerns. A new extended-release, once-daily formulation of niacin (Niaspan) shows promise in minimizing flushing while avoiding hepatotoxicity. A multicenter, randomized, double-blind clinical trial of Niaspan enrolled 122 patients with confirmed diagnosis of primary dyslipidemia (LDL cholesterol >4.14 mmol/L [160 mg/dL] and triglycerides <9 mmol/L [800 mg/dL]) into 3 treatment groups: (1) Niaspan 1,000 mg/day; (2) Niaspan 2,000 mg/day; and (3) placebo. The primary treatment endpoint was LDL-cholesterol level. This endpoint was not significantly affected by placebo (0.2% increase), but Niaspan decreased LDL cholesterol by 5.8% (1,000 mg/day) and 14.6% (2,000 mg/day) (p <0.001). Likewise, with placebo there were significant changes in total cholesterol, triglycerides, lipoprotein(a), and apoprotein B, whereas both Niaspan 1,000 and 2,000 mg/day significantly (p <0.001) decreased these parameters. In addition, both Niaspan groups showed significant (p <0.001) increases in HDL cholesterol (17% and 23%, respectively), including HDL subfractions. With respect to flushing, 20% of the placebo group reported at least 1 episode, whereas 88% and 83% of the Niaspon 1,000- and 2,000-mg/day groups, respectively, reported episodes. There was no hepatotoxicity as liver enzyme levels remained within clinically accepted limits in all treatment groups. However, Niaspan 2,000 mg/day showed a significant increase in aspartate aminotransferase compared with baseline and placebo. This trial demonstrated a cholesterol-modifying effect of Niaspan consistent with those reported for niacin, but demonstrated a better tolerance for flushing. Moreover, in contrast to sustained-release formulations, Niaspan showed relatively mild hepatic effects.
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PMID:A new extended-release niacin (Niaspan): efficacy, tolerability, and safety in hypercholesterolemic patients. 991 60

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