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

To explore the possibility of liver enzyme induction by deltamethrin, subacute intoxication was carried out in rats for 28 days, by administration 7.2 mg.Kg-1.day-1 of deltamethrin i.p. delivered by an osmotic pump inserted in the peritoneal cavity. The body weight curve of the treated rats increased slightly but not significantly compared to the controls. No neurotoxic effect was observed. Blood parameters were unchanged, except for eosinophilia and an increase in the plasma Na+ level. Cytochrome P-450, cytochrome b5, NADPH-cytochrome c reductase, esterases and the activities of six mixed function oxidases were assayed. No variation was noted. Ultrastructural study of the liver, more specially in midlobular region, showed that deltamethrin increased the number of mitochondria and altered their shape which became irregular. These findings were consistent with morphometric results. Succinate cytochrome c reductase, citrate synthase and cytochrome c oxidase were essayed, only this last showed a significant enhancement in deltamethrin treated rats.
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PMID:Effects on rats of subacute intoxication with deltamethrin via an osmotic pump. 263 42

The activities of citrate synthase and cytochrome c oxidase, mitochondrial marker enzymes, were evaluated in the liver of Ehrlich ascites carcinoma-bearing mice during the life span of the inoculated animals. After 10 days of tumour transplantation, when cell proliferation has ceased, a 30-40% decrease of these activities was detected in both liver and kidney. Simultaneously, an increase in the total acidic proteinase activity (50-60%) was observed. The gel filtration profiles of liver proteinase activities from inoculated animal extracts displayed different patterns to those of the controls; low molecular weight proteinase activities appear to be enhanced in the livers of tumour-bearing animals.
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PMID:Early systemic effects on the hepatic mitochondria of tumour bearing mice. 264 83

The relationship between capillarity and oxidative capacity in the soleus muscle of rats and guinea pigs injected with triiodothyronine (T3) or with saline for up to 4 weeks was studied. The rats' soleus weight and FCSA were not affected by T3, but the guinea pigs that received T3 had smaller muscle weight and FCSA than the controls. The activities of cytochrome c oxidase and citrate synthase were significantly (41 and 65%) higher in the T3 than in the control rats. T3 administration did not affect the activities of these enzymes in the soleus of the guinea pigs. Capillary density (CD) was higher in T3 rats (892 +/- 80 vs 622 +/- 54 caps/mm2), and in T3 guinea pigs (1219 +/- 95 vs 739 +/- 142 caps/mm2). The higher CD in T3 rats was due to growth of new microvessels, while in the T3 guinea pigs it was due to a reduction in FCSA. Mean and maximal diffusion distances evaluated by the closest individual method were reduced by 2.02 and 3.37 microns in rats, and by 3.73 and 6.16 microns in guinea pigs. The magnitude of the reduction in diffusion distances brought about by the increased capillary density was partially offset by a concomitant change in the capillary arrangement from an ordered (hexagonal), towards a random distribution. These results seem to indicate that skeletal muscle capillarity is not necessarily determined by the oxidative capacity of the fibers.
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PMID:Capillarity and oxygen diffusion distances of the soleus muscle of guinea pigs and rats. Effects of hyperthyroidism. 286 42

Nonselective and beta 1-selective adrenergic antagonists were tested for their effects on enzymatic adaptation to exercise training in rats as follows: trained + placebo (TC); trained + propranolol (TP); trained + atenolol (TA); and corresponding sedentary groups, SC and SP. Trained rats ran 1 h/d at 26.8 m/min, 15% grade, 5 d/wk, 10 wk. Both beta-antagonists were given at doses that decreased exercise heart rates by 25%. Training increased skeletal muscle citrate synthase, cytochrome c oxidase (Cyt-Ox), carnitine palmitoyltransferase (CPT), beta-hydroxyacyl coenzyme A dehydrogenase, mitochondrial malate dehydrogenase (MDH), and alanine aminotransferase (ALT) activities significantly in the TC group, but not in TP. These enzyme activities, except Cyt-Ox and CPT, were also significantly increased in TA. Hepatic phosphoenolpyruvate carboxykinase activity did not alter with training or beta-blockade. Fructose 1,6-bisphosphatase activity was lower in TC than in SC, but unchanged in TP or TA. Hepatic mitochondrial MDH and ALT activities increased with training only in TC. It is concluded that beta 2-adrenergic mechanisms play an essential role in the training-induced enzymatic adaptation in skeletal muscle.
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PMID:Enzymatic adaptation to physical training under beta-blockade in the rat. Evidence of a beta 2-adrenergic mechanism in skeletal muscle. 287 82

The main purpose of the present study was to test the hypothesis that adrenergic stimulation of muscle fibres during exercise is a major stimulus for the training-induced enhancement of skeletal muscle respiratory capacity. Therefore, Sprague-Dawley rats either underwent bilateral surgical ablation of the adrenal medulla or were sham-operated. Furthermore, unilateral surgical extirpation of the lumbar sympathetic chain was performed. Half of the rats were then trained for 12 weeks by swimming (up to 5.5 h X day-1, 4 days X week-1) and the remaining rats were sedentary controls. In the gastrocnemius muscle, training significantly increased the mitochondrial enzymes citrate synthase, succinate dehydrogenase, cytochrome c oxidase, and 3-hydroxyacyl-CoA dehydrogenase. In sham-operated rats, the increases were 40%, 43%, 66%, and 25%, respectively, in legs with intact sympathetic innervation. The training-induced enzyme adaptation after adrenodemedullation and/or sympathectomy was not significantly lower than these control values. In sham-operated rats, training decreased resting plasma insulin and glucagon levels and increased liver glycogen content. Similar changes were induced by adrenodemedullation, but training did not augment these changes in adrenodemedullated rats. In conclusion, the data suggest that neither adrenomedullary hormones nor local sympathetic nerves are prerequisites for the training-induced increase in muscle mitochondrial enzymes. The training-induced decline in resting plasma insulin and glucagon levels in intact rats may be mediated by adrenomedullary hormones.
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PMID:Skeletal muscle and hormonal adaptation to physical training in the rat: role of the sympatho-adrenal system. 298 95

A rat model was developed in which the adaptive effects of exposing skeletal muscle tissue to a reduced blood flow during muscle contractions could be studied. The common iliac artery was ligated in one hindlimb, using the other as control. This procedure reduced the exercise blood flow to the individual muscles of the lower limb by 76-93%, evaluated with the microsphere technique. Muscle contractions were induced by electrical stimulation of the sciatic nerves in both legs. After intermittent stimulation for 6 days, a significant increase in citrate synthase and cytochrome c oxidase activities was found in the soleus (26%) and extensor digitorum longus (EDL, 20%) muscles of the ligated legs compared with the control legs. Resting metabolite concentrations were also measured, and a reduction of the ATP level (soleus 35%, EDL 14%) and an increased glycogen content (55-71%) were found. These results demonstrate that a reduced blood flow during muscle contractions provokes an adaptive increase of the oxidative enzyme capacity as well as altered resting levels of intracellular metabolites.
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PMID:Metabolic adaptation to reduced muscle blood flow. I. Enzyme and metabolite alterations. 299 Feb 34

The postnatal development, between 0 and 90 days, of three hindlimb muscles and diaphragm of the rat was investigated with respect to fiber types and diameter (histochemistry) and substrate oxidation rates and enzyme activities (biochemistry). The process of muscle fiber differentiation into mature patterns was evaluated by visual classification into 3 or 4 groups having different staining intensities for 3 enzyme-histochemical reactions, enabling 26 fiber types to be distinguished. These exhibited specific sizes and growth rates that varied among the muscles. One of the hindleg muscles (flexor digitorum brevis) remained much more immature than soleus and extensor digitorum longus. The histochemical and biochemical findings correlated well. The capacity for pyruvate and palmitate oxidation, and the activities of cytochrome c oxidase and citrate synthase, increased markedly between 9 and 37 days in soleus and extensor digitorum longus (except citrate synthase in the latter) but not in flexor digitorum brevis. Creatine kinase activity increased in all hindlimb muscles. Both the capacity and the activity of pyruvate oxidation (determined in homogenates and intact isolated muscles, respectively), were in accordance with the fiber type composition. In contrast to oxidation capacity, the activity of pyruvate oxidation decreased after birth until the mature stage, when a value of 18-42% of that of early postnatal muscles was recorded.
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PMID:Postnatal growth and differentiation in three hindlimb muscles of the rat. Characterization with biochemical and enzyme-histochemical methods. 299 92

Oxidation rates of palmitate, pyruvate and 2-oxoisocaproate and activities of cytochrome c oxidase and citrate synthase were assayed in heart homogenates of newborn and adult rats and of adult man. All activities doubled or increased more in rat heart at maturation. The rise was due to an increase of both mitochondrial activity and content. In human heart all activities and mitochondrial content were lower than in newborn rat heart.
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PMID:Metabolic changes during cardiac maturation. 299 28

Although replication of nuclear DNA is inhibited by cytarabine (ara-C), protein synthesis in the nucleocytoplasm appears to continue unabated for the duration of at least the time of the normal cell cycle. ara-C treatment of human leukemic cells resulted in increased mitochondrial membrane potential and adenosine-5'-triphosphate (ATP) production and increased activity of enzymes, coded on nuclear DNA (citrate synthetase), as well as of enzymes with subunits coded on mitochondrial DNA (cytochrome c oxidase). These mitochondrial changes occurred during a period of cell-cycle arrest, while cell size and cellular protein content continued to increase. These phenomena appeared to precede the ultimate cell death.
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PMID:Influence of cytarabine on mitochondrial function and mitochondrial biogenesis. 303 19

1. Palmitate oxidation rates and activities of creatine kinase, cytochrome c oxidase and citrate synthase were determined in homogenates of three different human muscles and their derived muscle cell cultures. Palmitate oxidation was also assayed in intact cultured cells (myotubes). 2. Biopsies obtained from m. rectus abdominis exhibited a lower palmitate oxidation rate and lower activities of citrate synthase and cytochrome c oxidase than those from m. gluteus and m. quadriceps. In contrast, cell cultures obtained from the three muscles were mutually comparable with regard to these mitochondrial activities. 3. Although cell cultures only reached a low differentiation grade (judged by the total creatine kinase activity and percentage isoenzyme-MM) they are well comparable with the original biopsies with respect to citrate synthase activity and capacity of palmitate oxidation. The activity of cytochrome c oxidase was clearly lower in the cultured cells. 4. Palmitate was more completely oxidized in intact myotubes than in homogenates of myotubes. Apparent Km and Vmax values of palmitate oxidation did not differ significantly in homogenates and intact preparations of myotubes.
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PMID:Palmitate oxidation and some enzymes of energy metabolism in human muscles and cultured muscle cells. 342 77


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