Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Procedures were developed for the extraction and assay of glycolytic enzymes from the epididymis and epididymal spermatozoa of the rat. 2. The epididymis was separated into four segments for analysis. When rendered free of spermatozoa by efferent duct ligation, regional differences in enzyme activity were apparent. Phosphofructokinase, glycerol phosphate dehydrogenase and glucose 6-phosphate dehydrogenase were more active in the proximal regions of the epididymis, whereas hexokinase, lactate dehydrogenase and phosphorylase were more active in the distal segment. These enzymes were less active in the epididymis of castrated animals and less difference was apparent between the proximal and distal segments. However, the corpus epididymidis from castrated rats had lower activities of almost all enzymes compared with other epididymal segments. 3. Spermatozoa required sonication to obtain satisfactory enzyme release. Glycolytic enzymes were more active in spermatozoa than in epididymal tissue, being more than 10 times as active in the case of hexokinase, phosphoglycerate kinase and phosphoglycerate mutase. 4. The specific activities of a number of enzymes in the epididymis were dependent on the androgen status of the animal. These included hexokinase, phosphofructokinase, aldolase, glyceraldehyde phosphate dehydrogenase, phosphoglycerate kinase, pyruvate kinase, glycerol phosphate dehydrogenase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and phosphorylase. 5. The caput and cauda epididymidis differed in the extent to which enzyme activities changed in response to an altered androgen status. The most notable examples were hexokinase, phosphofructokinase, aldolase, phosphoglycerate kinase, 6-phosphogluconate dehydrogenase and phosphorylase.
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PMID:Activity and androgenic control of glycolytic enzymes in the epididymis and epididymal spermatozoa of the rat. 18 56

Seven enzymes of the Embden-Myerhof pathway of glycolysis were assayed in hypotonically treated epididymal sperm from mature rabbits. These were: fructose-biphosphate aldolase, triosephosphate isomerase, glyceraldehydephosphate dehydrogenase, 3-phosphoglyceromutase, enolase, pyruvate kinase, and lactate dehydrogenase. These enzymes were firmly enough bound to the cell structure to resist removal by washing after hypotonic treatment and had maximal activities comparable to, or greater than, the rate of mitochondrial pyruvate oxidation, so that rapid oxygen uptake was observed with intermediates of the glycolytic pathway. The activity of lactate dehydrogenase in a typical preparation of hypotonically treated cells was 5.3 mumoles/minute x 10(9) cells at 25 degrees C for pyruvate reduction in the hypotonically treated cells and 4.8 mumoles/minute x 10(9) cells in the thrice-washed hypotonically treated cells. The Km for pyruvate was 1.4 mM while that for lactate was 4.4 mM. By contrast, the maximal activity of pyruvate oxidation by mitochondria was 0.10 microgram atom of oxygen/minute x 10(9) cells, corresponding to 0.020 mumole of pyruvate/minute x 10(9) cells, and the Km for pyruvate was 5 microM. These enzyme parameters favor high lactate production from glucose in aerobic glycolysis.
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PMID:Energy metabolism of spermatozoa. V. The Embden-Myerhof pathway of glycolysis: activities of pathway enzymes in hypotonically treated rabbit epididymal spermatozoa. 80 42