Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.4.1 (myosin ATPase)
 1,140 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The histochemical and ultrastructural effects of extracorporeal circulation and aortic cross-clamping during coronary heart surgery have been examined in drill biopsy samples of the left ventricle in 22 patients. The biopsies were obtained before and after bypass with a DeSoutter drill. Histochemical studies indicated definite differences between control and experimental biopsies, with increased succinic dehydrogenase, cytochrome oxidase, and LDH activity, while phosphorylase A and myosin ATPase activities declined. Furthermore, free phospholipid levels increased, as determined by the acid hematein reaction. Ultrastructural examination demonstrated loss of glycogen, intracellular swelling, and mitochondrial damage, which included loss of matrix density, loss of cristae, and eventual disruption in the postbypass biopsy. These results, which closely resemble the effects of ischemia and reperfusion observed in animal experiments, suggest that the initial insult is a change in membrane permeability regulation.
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PMID:Histochemical and structural changes in human myocardial cells after cardiopulmonary bypass. 16 88

We studied muscle fibers by quantitative biochemistry to determine whether metabolic capacity varied among fibers of a given type as a function of their anatomic location. Muscles were selected from both contiguous and diverse anatomic regions within the rats studied. The individual fibers, classified into myosin ATPase fiber types by histochemical means, were assessed for fiber diameters and analyzed for the activities of enzymes representing major energy pathways: malate dehydrogenase (MDH, oxidative), lactate dehydrogenase (LDH, glycolytic), and adenylokinase (AK, high-energy phosphate metabolism). We found that neither the average activities of each of the three enzymes nor the fiber diameters varied in Type I or Type IIa fibers selected from superficial to deep portions of the triceps surae of the hindlimb. However, the IIb fibers in the deep region of this muscle group had significantly greater oxidative capacity, less glycolytic capacity, and smaller diameters than the superficially situated IIb fibers. Type IIa fibers in lateral gastrocnemius, extensor digitorum longus, psoas, diaphragm, biceps brachii, superficial masseter, and superior rectus muscles were highly variable in both diameter and enzyme profiles, with a correlation between MDH activity and fiber diameter. Therefore, our results show that both intermuscular and intramuscular metabolic variations exist in muscle fibers of a given type.
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PMID:Metabolic capacity of individual muscle fibers from different anatomic locations. 158 28