Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.3.1 (citrate synthase)
 4,488 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fast-twitch tibialis anterior muscle of the rabbit was subjected to chronic low-frequency (10 Hz, 10 h/day) stimulation for different time periods up to 28 days. Total cellular activities of carnitine:palmitoyl-CoA transferase, crotonase, 3-hydroxyacyl-CoA dehydrogenase, 3-keto-acyl-CoA thiolase, citrate synthase, NADH:cytochrome c oxidoreductase, succinate: cytochrome c oxidoreductase, and cytochrome c oxidase were measured in contralateral and stimulated muscles at various times. With the exception of crotonase, which increased only 1.6-fold after 28 days of stimulation, the other enzymes increased in parallel displaying 3-fold elevated absolute activities. These results, by supporting and extending our previous findings, indicate that the expression of the enzymes of the main metabolic systems of aerobic substrate oxidation, i.e. the citric acid cycle, the fatty acid oxidation and the respiratory chain, is regulated in a coordinate manner.
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PMID:Enzyme activities of fatty acid oxidation and the respiratory chain in chronically stimulated fast-twitch muscle of the rabbit. 194 50

We studied two diagnostic aspects of fatal infantile defects of the mitochondrial respiratory chain: the age dependence of muscle mitochondrial enzyme activities and the reliability of diagnosis from autopsy samples. In morphologically normal quadriceps muscle samples of 46 children between the ages of 3 days and 15 years, activities of complex I plus III (NADH:cytochrome c oxidoreductase) and complex II plus III (succinate:cytochrome c oxidoreductase) increased 2-fold during the first three years of life, while that of complex II (succinate dehydrogenase), complex IV (cytochrome c oxidase), and citrate synthase did not show significant correlation with age. We suggest that these changes are related to age and stress the importance of strictly age-matched controls when diagnosing a mitochondrial disease of early childhood. The value of autopsy samples in diagnostic studies was evaluated by comparing mitochondrial enzyme activities in quadriceps muscle from autopsies and from surgical biopsies. In quadriceps muscle mitochondria, all the enzyme activities studied remained stable for at least 3 h after death. Using age-matched controls and autopsy samples, we diagnosed a respiratory chain enzyme deficiency in two infants, and the defects were confirmed in cultured skin fibroblasts.
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PMID:Diagnosis of fatal infantile defects of the mitochondrial respiratory chain: age dependence and postmortem analysis of enzyme activities. 874 50

Mitochondria are affected by endogenous nitric oxide (NO). Besides effects of NO on mitochondrial enzymes and the stimulation of mitochondrial H2O2 production, a NO-dependent increase in mitochondrial biogenesis in several tissues has been reported. It is still obscure whether NO generated by one specific or different NO synthase (NOS) isoenzymes determine such effects. Therefore, we analyzed the amount of mitochondria, respiratory chain enzyme complexes, and citrate synthase in the brain, muscle, heart, kidney, and liver by comparing wild-type (WT) mice and mice lacking the neuronal nitric oxide synthase isoform (nNOS-KO). Our results show that the activities of NADH:cytochrome c oxidoreductase and succinate cytochrome c oxidoreductase differ between WT and nNOS-KO mice. However, similar quantities of mitochondria were found in the homogenates of tissues in WT and nNOS-KO animals. Most impressive, higher activities and protein of citrate synthase were found in the brain, muscle, heart, kidney, and liver of nNOS-KO mice. Additionally, higher contents of fatty acid synthase and lipids were determined in the livers of nNOS-KO mice but not in the heart and brain. Furthermore, liver mitochondria from nNOS-KO mice consumed pyruvate at a higher rate and released more citric acid. Our data document a previously unrecognized role of endogenous NO in the regulation of lipid metabolism.
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PMID:Neuronal nitric oxide synthase controls enzyme activity pattern of mitochondria and lipid metabolism. 1624 68