Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Quantitative cytochemical methods were applied to measure the activity of several oxidative enzymes in human articular cartilage of the femoral head obtained from osteoarthritic patients (OA) and from patients with fractured femoral neck (OP) due to primary osteoporosis. In both conditions, lactate dehydrogenase (LDH) was found to be the most active one followed by two additional cytosolic enzymes: glyceraldehyde 3-phosphate dehydrogenase (GAPD) and glucose 6-phosphate dehydrogenase (G6PD). On the other hand, the activity of mitochondrial enzymes such as succinate dehydrogenase (SDH) and beta-hydroxyacyl dehydrogenase (HOAD), appeared much lower in degree. Except for HOAD, all the other enzymes exhibited a high degree of activity along the inner zone in the cartilage, i.e., zone 3b, indicative of an apparently more active metabolism in the osteochondral junction. G6PD activity was significantly higher (p less than 0.01) in OP than in OA patients. By contrast, SDH appeared more active in specimens obtained from OA patients. The remaining enzymes showed no appreciable activity differences between cartilages of OP and OA patients. These findings suggest that oxidative enzyme activity in chondrocytes involved in osteoarthritis does not differ substantially from that in cartilage of OP patients.
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PMID:Cellular enzymatic activities in the articular cartilage of osteoarthritic and osteoporotic hip joints of humans: a quantitative cytochemical study. 209 76

It has been proposed that highly biosynthetic cells oxidize fatty acids to generate ATP while maintaining high levels of glucose metabolism through the glycolytic and pentose shunt systems to supply biosynthetic intermediates. We investigated the metabolic strategies and substrate for ATP production in the osteoclast. We used in situ quantitative microcytophotometric techniques to determine the maximal activity of the pentose shunt (glucose-6-phosphate dehydrogenase; G6PD), the glycolytic pathway (glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase; G3PD and LDH), fatty acid oxidation (beta-hydroxyacyl dehydrogenase; HOAD), and the Krebs cycle (succinate dehydrogenase; SDH) in human osteoclasts in situ, and related these enzyme activities to the degree of involvement of the cells in resorption. Unlike other highly biosynthetic cells, such as chondrocytes and macrophage polykaryons, osteoclasts associated with bone resorption were deficient in G3PD, LDH, and G6PD activity. However, osteoclasts did demonstrate a capacity for fatty acid oxidation which increased in cells apposed to the bone surface. The lack of significant glycolytic and pentose shunt activity in the osteoclast provides good evidence that resorbing osteoclasts, unlike phagocytosing macrophage polykaryons, have the metabolic characteristics of cells with greatly reduced capabilities of de novo mRNA synthesis but which do maintain high rates of ATP production. The possibility that the loss of glycolytic activity is a prelude to cell death is discussed.
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PMID:Microcytophotometric analysis of human osteoclast metabolism: lack of activity in certain oxidative pathways indicates inability to sustain biosynthesis during resorption. 815 31