Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of this study was to determine whether cardiac biochemical adaptations are induced by chronic exercise training (ET) of miniature swine. Female Yucatan miniature swine were trained on a treadmill or were cage confined (C) for 16-22 wk. After training, the ET pigs had increased exercise tolerance, lower heart rates during exercise at submaximal intensities, moderate cardiac hypertrophy, increased coronary blood flow capacity, and increased oxidative capacity of skeletal muscle. Myosin from both the C and ET hearts was 100% of the V3 isozyme, and there were no differences between the myosin adenosine triphosphatase (ATPase) or myofibrillar ATPase activities of C and ET hearts. Also, the sarcoplasmic reticulum Ca(2+)-ATPase activity and Na(+)-Ca2+ exchange activity of sarcolemmal vesicles were the same in cardiac muscle of C and ET hearts. Finally, the glycolytic and oxidative capacity of ET cardiac muscle was not different from control, since phosphofructokinase, citrate synthase, and 3-hydroxyacyl-CoA dehydrogenase activities were the same in cardiac tissue from ET and C pigs. We conclude that endurance exercise training does not provide sufficient stress on the heart of a large mammal to induce changes in any of the three major cardiac biochemical systems of the porcine myocardium: the contractile system, the Ca2+ regulatory systems, or the metabolic system.
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PMID:Biochemical characterization of exercise-trained porcine myocardium. 183 67

Fibers of the garter snake transversus abdominis muscle fall into three classes according to contraction speed: faster and slower twitch and tonic. To determine the relationship between these physiologically determined classes and established mammalian fiber types, individual fibers were assayed for key enzymes representing the major energy-generating pathways in vertebrate muscle. Five such enzymes were examined: lactate dehydrogenase, malate dehydrogenase, adenylokinase, fumarate hydratase, and beta-hydroxyacyl-CoA dehydrogenase. The muscle contained three principal metabolic fiber types. Fast-contracting twitch fibers had low-oxidative but high-glycolytic capacity and therefore resembled mammalian-type fast-twitch glycolytic (FG) fibers. Slower twitch fibers were high oxidative-high glycolytic, similar to mammalian-type fast-twitch, oxidative, glycolytic (FOG) fibers. Tonic fibers were high oxidative-low glycolytic; this metabolic profile is characteristic of type slow-twitch oxidative (SO) fibers in mammals. Activity of the enzyme adenylokinase, which in mammals correlates with contraction speed and myosin adenosine triphosphatase (ATPase) activity, separated these reptilian fibers into three groups that are similar but not identical to those delineated by oxidative and glycolytic enzymes. Adenylokinase and beta-hydroxyacyl-CoA dehydrogenase showed the widest range of activities in snake muscle and, therefore, the greatest ability to discriminate fiber types.
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PMID:Metabolic fiber types of snake transversus abdominis muscle. 273 94