Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0264733 (ventricular dilatation)
 2,163 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several experimental studies have shown that levocarnitine reduces myocardial injury after ischemia and reperfusion by counteracting the toxic effect of high levels of free fatty acids, which occur in ischemia, and by improving carbohydrate metabolism. In addition to increasing the rate of fatty acid transport into mitochondria, levocarnitine reduces the intramitochondrial ratio of acetyl-CoA to free CoA, thus stimulating the activity of pyruvate dehydrogenase and increasing the oxidation of pyruvate. Supplementation of the myocardium with levocarnitine results in an increased tissue carnitine content, a prevention of the loss of high-energy phosphate stores, ischemic injury, and improved heart recovery on reperfusion. Clinically, levocarnitine has been shown to have anti-ischemic properties. In small short-term studies, levocarnitine acts as an antianginal agent that reduces ST segment depression and left ventricular end-diastolic pressure. These short-term studies also show that levocarnitine releases the lactate of coronary artery disease patients subjected to either exercise testing or atrial pacing. These cardioprotective effects have been confirmed during aortocoronary bypass grafting and acute myocardial infarction. In a randomized multicenter trial performed on 472 patients, levocarnitine treatment (9 g/day by intravenous infusion for 5 initial days and 6 g/day orally for the next 12 months), when initiated early after acute myocardial infarction, attenuated left ventricular dilatation and prevented ventricular remodeling. In treated patients, there was a trend towards a reduction in the combined incidence of death and CHF after discharge. Levocarnitine could improve ischemia and reperfusion by (1) preventing the accumulation of long-chain acyl-CoA, which facilitates the production of free radicals by damaged mitochondria; (2) improving repair mechanisms for oxidative-induced damage to membrane phospholipids; (3) inhibiting malignancy arrhythmias because of accumulation within the myocardium of long-chain acyl-CoA; and (4) reducing the ischemia-induced apoptosis and the consequent remodeling of the left ventricle. Propionyl-L-carnitine is a carnitine derivative that has a high affinity for muscular carnitine transferase, and it increases cellular carnitine content, thereby allowing free fatty acid transport into the mitochondria. Moreover, propionyl-L-carnitine stimulates a better efficiency of the Krebs cycle during hypoxia by providing it with a very easily usable substrate, propionate, which is rapidly transformed into succinate without energy consumption (anaplerotic pathway). Alone, propionate cannot be administered to patients in view of its toxicity. The results of phase-2 studies in chronic heart failure patients showed that long-term oral treatment with propionyl-L-carnitine improves maximum exercise duration and maximum oxygen consumption over placebo and indicated a specific propionyl-L-carnitine effect on peripheral muscle metabolism. A multicenter trial on 537 patients showed that propionyl-L-carnitine improves exercise capacity in patients with heart failure, but preserved cardiac function.
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PMID:Therapeutic effects of L-carnitine and propionyl-L-carnitine on cardiovascular diseases: a review. 1559 Oct 5

It has been recently recognized that mammalian mitochondria contain most, if not all, of the components of fatty acid synthesis type II (FAS II). Among the components identified is 2-enoyl thioester reductase/mitochondrial enoyl-CoA reductase (Etr1/Mecr), which catalyzes the NADPH-dependent reduction of trans-2-enoyl thioesters, generating saturated acyl-groups. Although the FAS type II pathway is highly conserved, its physiological role in fatty acid synthesis, which apparently occurs simultaneously with breakdown of fatty acids in the same subcellular compartment in mammals, has remained an enigma. To study the in vivo function of the mitochondrial FAS in mammals, with special reference to Mecr, we generated mice overexpressing Mecr under control of the mouse metallothionein-1 promoter. These Mecr transgenic mice developed cardiac abnormalities as demonstrated by echocardiography in vivo, heart perfusion ex vivo, and electron microscopy in situ. Moreover, the Mecr transgenic mice showed decreased performance in endurance exercise testing. Our results showed a ventricular dilatation behind impaired heart function upon Mecr overexpression, concurrent with appearance of dysmorphic mitochondria. Furthermore, the data suggested that inappropriate expression of genes of FAS II can result in the development of hereditary cardiomyopathy.
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PMID:Myocardial overexpression of Mecr, a gene of mitochondrial FAS II leads to cardiac dysfunction in mouse. 1944 Mar 39