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)

Adipose tissue and liver from vitamin B6-deficient rats have an increased lipogenic capacity. Whether this phenomenon is accompanied by changes in the activities of certain enzymes involved in the metabolism of carbohydrate and lipid, or by altered transport of glucose into adipocytes, has been studied. Five glycolytic enzymes (hexokinase, phosphoglucose isomerase, phosphofructokinase, aldolase, and pyruvate kinase), two pentose phosphate pathway enzymes (glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase), malic enzyme, and ATP citrate lyase were measured in the epididymal adipose tissue, livers and kidneys of vitamin B6-deficient and control rats. Vitamin B6 deficiency did not significantly affect the glycolytic enzyme levels in the tissues studied, or the dehydrogenases measured in adipose tissue and kidneys. Liver glucose-6-phosphate dehydrogenase, and adipose tissue and liver malic enzyme were significantly lowered in deficient rats compared to ad libitum and pair-fed controls. Adipose tissue and liver ATP citrate lyase activities were also significantly decreased by vitamin B6 deficiency. In the presence of insulin, the uptake of glucose and 3-O-methyl glucose, a non-metabolizable sugar, by fat pads from deficient rats was greater than uptake by fat pads from control rats. These observations suggest that the increased glucose utilization by adipose tissue and liver of vitamin B6-deficient rats is not directly related to changes in the enzymes studied, but in the case of adipose tissue, may be explained, at least in part, by enhanced glucose uptake.
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PMID:Effects of vitamin B6 deficiency on liver, kidney, and adipose tissue enzymes associated with carbohydrate and lipid metabolism, and on glucose uptake by rat epididymal adipose tissue. 13 63

The effects of the male antifertility agent ornidazole on glycolysis as a prerequisite for fertilization were investigated in rats. Antifertility doses of ornidazole inhibited glycolysis within mature spermatozoa as determined from the lack of glucose utilization, reduced acidosis under anaerobic conditions and reduced glycolytic enzyme activity. As a consequence, cauda epididymidal spermatozoa from ornidazole-fed rats were unable to fertilize rat oocytes in vitro, with or without cumulus cells, which was not due to transfer of an inhibitor in epididymal fluid with the spermatozoa. Under IVF conditions, binding to the zona pellucida was reduced in spermatozoa from ornidazole-fed males and the spermatozoa did not undergo a change in swimming pattern, which was observed in controls. The block to fertilization could be explained by the disruption of glycolysis-dependent events, since reduced binding to the zona pellucida and a lack of kinematic changes were demonstrated by control spermatozoa in glucose-free media in the presence of respiratory substrates. The importance of glycolysis for binding to, and penetration of, the zona pellucida, and hyperactivation in rats is discussed in relation to the glycolytic production of ATP in the principal piece in which local deprivation of energy may explain the reduced force of spermatozoa from ornidazole-fed males.
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PMID:Effect of ornidazole on fertility of male rats: inhibition of a glycolysis-related motility pattern and zona binding required for fertilization in vitro. 1079 34

The fibrous sheath is a cytoskeletal structure located in the principal piece of mammalian sperm flagella. Previous studies showed that glyceraldehyde 3-phosphate dehydrogenase, spermatogenic (GAPDHS), a germ cell-specific glycolytic isozyme that is required for sperm motility, is tightly bound to the fibrous sheath. To determine if other glycolytic enzymes are also bound to this cytoskeletal structure, we isolated highly purified fibrous sheath preparations from mouse epididymal sperm using a sequential extraction procedure. The isolated fibrous sheaths retain typical ultrastructural features and exhibit little contamination by axonemal or outer dense fiber proteins in Western blot analyses. Proteomic analysis using peptide-mass fingerprinting and MS/MS peptide fragment ion matching identified GAPDHS and two additional glycolytic enzyme subunits, the A isoform of aldolase 1 (ALDOA) and lactate dehydrogenase A (LDHA), in isolated fibrous sheaths. The presence of glycolytic enzymes in the fibrous sheath was also examined by Western blotting. In addition to GAPDHS, ALDOA, and LDHA, this method determined that pyruvate kinase is also tightly bound to the fibrous sheath. These data support a role for the fibrous sheath as a scaffold for anchoring multiple glycolytic enzymes along the length of the flagellum to provide a localized source of ATP that is essential for sperm motility.
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PMID:Multiple glycolytic enzymes are tightly bound to the fibrous sheath of mouse spermatozoa. 1668 49

Synthesis of triacylglycerol requires the glucose-derived glycerol component, and glucose uptake has been viewed as the rate-limiting step in glucose metabolism in adipocytes. Furthermore, adipose tissue contains all three isoforms of the glycolytic enzyme phosphofructokinase (PFK). We here report that mice deficient in the muscle isoform PFK-M have greatly reduced fat stores. Mice with disrupted activity of the PFK-M distal promoter were obtained from Lexicon Pharmaceuticals, developed from OmniBank OST#56064. Intra-abdominal fat was measured by magnetic resonance imaging of the methylene proton signal. Lipogenesis from labeled glucose was measured in isolated adipocytes. Lipolysis (glycerol and free fatty acid release) was measured in perifused adipocytes. Intra-abdominal fat in PFK-M-deficient female mice (5-10 months old) was 17 +/- 3% of that of wild-type littermates (n = 4; P < 0.02). Epididymal fat weight in 15 animals (7-9.5 months) was 34 +/- 4% of control littermate (P < 0.002), with 10-30% lower body weight. Basal and insulin-stimulated lipogenesis in PFK-M-deficient epididymal adipocytes was 40% of the rates in cells from heterozygous littermates (n = 3; P < 0.05). The rate of isoproterenol-stimulated lipolysis in wild-type adipocytes declined approximately 10% after 1 h and 50% after 2 h; in PFK-M-deficient cells it declined much more rapidly, 50% in 1 h and 90% in 2 h, and lipolytic oscillations appeared to be damped (n = 4). These results indicate an important role for PFK-M in adipose metabolism. This may be related to the ability of this isoform to generate glycolytic oscillations, because such oscillations may enhance the production of the triacylglycerol precursor alpha-glycerophosphate.
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PMID:Mice deficient in phosphofructokinase-M have greatly decreased fat stores. 1977 79