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)

The purpose of this study was to test the hypothesis that calcineurin, a calcium-dependent protein phosphatase recently implicated in the signaling of skeletal muscle hypertrophy and fiber type conversion, is required to induce some mitochondrial enzyme adaptations to endurance exercise training in skeletal muscle. Three- to four-week-old male Sprague-Dawley rats with an initial body weight ranging from 45 to 55 g were used in this study. The rats were randomly assigned to groups injected with either a specific calcineurin inhibitor, cyclosporin A (CsA), (group CI) or vehicle (group VI). CsA was subcutaneously injected into the rats at a rate of 50 mg.kg(-1) body weight per day for 10 days. The CI and VI groups were further assigned to sedentary (SED) or exercise training (EX) groups. In the EX group, the rats were trained for 10 days (90 min.day(-1), approximately 14-20 m.min(-1), 10% grade). The citrate synthase (CS) activities in the soleus and plantaris muscles of the EX group rats were significantly higher than those of the SED group rats ( p<0.001). Furthermore, 3-beta-hydroxyacyl-CoA dehydrogenase (3-HAD) activities in the soleus and plantaris muscles were significantly higher in the EX group rats than in the SED group rats ( p<0.001). However, there were no significant differences in CS and 3-HAD activities between the VI and CI groups. The interactions between CsA injection and exercise training were not statistically significant in any of the parameters. These results may suggest that calcineurin is not involved in some mitochondrial enzyme adaptations to endurance exercise training.
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PMID:Calcineurin is not involved in some mitochondrial enzyme adaptations to endurance exercise training in rat skeletal muscle. 1285 86

1. The present study was designed to examine the role of calcineurin in muscle metabolic components by the administration of the specific calcineurin inhibitor cyclosporine A (CsA) to rats. 2. Male Wistar rats were divided into either a CsA-treated group (CT) or a vehicle-treated group (VT). Cyclosporine A was administered subcutaneously to rats at a rate of 25 mg/kg bodyweight per day for 10 successive days. Thereafter, changes in muscle enzyme activities and glucose transporter (GLUT)-4 and monocarboxylate transporter (MCT)-1 and MCT-4 proteins in the slow-twitch soleus and fast-twitch extensor digitorum longus (EDL) muscles were examined. 3. There was a significant increase in MCT-1 and MCT-4 proteins in the soleus muscle in the CT group, but not in the EDL muscle. The activities of hexokinase, pyruvate kinase and lactate dehydrogenase in the soleus muscle also increased significantly in the CT group, but a similar increase in enzyme activity was not seen in EDL muscle. The activities of citrate synthase or malate dehydrogenase and the GLUT-4 protein content were not altered by CsA treatment in either the soleus or EDL muscles. 4. These results seem to imply that calcineurin negatively regulates the components of glucose/lactate metabolism, except for GLUT-4, especially in slow-twitch muscle.
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PMID:Inhibition of calcineurin increases monocarboxylate transporters 1 and 4 protein and glycolytic enzyme activities in rat soleus muscle. 1574 6