Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.2.13 (aldolase)
 3,461 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

Various enzymes of glycolysis (hexokinase, phosphoglucoisomerase, aldolase and lactate dehydrogenase), the Krebs cycle (isocitrate, succinic and malate dehydrogenases), and the pentose phosphate cycle (glucose-6-phosphate and 6-phosphogluconate dehydrogenases) were studied in buffalo spermatozoa by biochemical and cytochemical methods. The enzymes of glycolysis were found to be loosely bound whereas those of the Krebs and pentose phosphate cycles were strongly bound to mitochondrial membranes. All the enzymes studied were localized histochemically in the mid-piece.
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PMID:Glycolytic, Krebs cycle and pentose phosphate cycle enzymes in spermatozoa of the buffalo (Bubalus bubalis). 51 3

1. The effect of alpha-chlorohydrin on the metabolism of glycolytic and tricarboxylate-cycle substrates by ram spermatozoa was investigated. The utilization and oxidation of fructose and triose phosphate were much more sensitive to inhibition by alpha-chlorohydrin (0.1-1.0mm) than lactate or pyruvate. Inhibition of glycolysis by alpha-chlorohydrin is concluded to be between triose phosphate and pyruvate formation. Oxidation of glycerol was not as severely inhibited as that of the triose phosphate. This unexpected finding can be explained in terms of competition between glycerol and alpha-chlorohydrin. A second, much less sensitive site, of alpha-chlorohydrin inhibition appears to be associated with production of acetyl-CoA from exogenous and endogenous fatty acids. 2. Measurement of the glycolytic intermediates after incubation of spermatozoal suspensions with 15mm-fructose in the presence of 3mm-alpha-chlorohydrin showed a ;block' in the conversion of glyceraldehyde 3-phosphate into 3-phosphoglycerate. alpha-Chlorohydrin also caused conversion of most of the ATP in spermatozoa into AMP. After incubation with 3mm-alpha-chlorohydrin, glyceraldehyde 3-phosphate dehydrogenase and triose phosphate isomerase activities were decreased by approx. 90% and 80% respectively, and in some experiments aldolase was also inhibited. Other glycolytic enzymes were not affected by a low concentration (0.3mm) of alpha-chlorohydrin. Loss of motility of spermatozoa paralleled the decrease in glyceraldehyde 3-phosphate dehydrogenase activity. alpha-Chlorohydrin, however, did not inhibit glyceraldehyde 3-phosphate dehydrogenase or triose phosphate isomerase in sonicated enzyme preparations when added to the assay cuvette. 3. Measurement of intermediates and glycolytic enzymes in ejaculated spermatozoa before, during and after injection of rams with alpha-chlorohydrin (25mg/kg body wt.) confirmed a severe block in glycolysis in vivo at the site of triose phosphate conversion into 3-phosphoglycerate within 24h of the first injection. Glyceraldehyde 3-phosphate dehydrogenase activity was no longer detectable and both aldolase and triose phosphate isomerase were severely inhibited. Spermatozoal ATP decreased by 92% at this time, being quantitatively converted into AMP. At 1 month after injection of alpha-chlorohydrin glycolytic intermediate concentrations returned to normal in the spermatozoa but ATP was still only 38% of the pre-injection concentration. Motility of spermatozoa was, however, as good as during the pre-injection period. The activity of the inhibited enzymes also returned to normal during the recovery period and 26 days after injection were close to pre-injection values. 4. An unknown metabolic product of alpha-chlorohydrin is suggested to inhibit glyceraldehyde 3-phosphate dehydrogenase and triose phosphate isomerase of spermatozoa. This results in a lower ATP content, motility and fertility of the spermatozoa. Glycidol was shown not to be an active intermediate of alpha-chlorohydrin in vitro.
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PMID:Mode of action of alpha-chlorohydrin as a male anti-fertility agent. Inhibition of the metabolism of ram spermatozoa by alpha-chlorohydrin and location of block in glycolysis. 62 80

Treatment with the polyene antibiotic, filipin, renders the spermatozoan cell membrane permeable to small molecules, but not to the intracellular enzymes aldolase and lactate dehydrogenase. Pyruvate (10 mM) as the sole substrate was metabolized very slowly. L-Carnitine increased pyruvate metabolism 3- to 4-fold and allowed limited rates of oxidative phosphorylation. When spermatozoa treated with filipin were supplemented with malate, there was a rapid, almost linear rate of pyruvate metabolism which was slightly increased by L-carnitine. In the absence of malate, 20 to 30% of the pyruvate used was reduced to lactate; this increased to 57% in the presence of malate. Without malate, about 90% of the pyruvate metabolized was converted to lactate and acetate or L-acetylcarnitine. Rutamycin or rotenone increased both the rate of pyruvate use and the delta lactate/deltapyruvate ratio. Under all treatments, L-carnitine consistently reduced the percentage of pyruvate converted to lactate by about 10%; part of the pyruvate was preferentially shunted into L-acetylcarnitine rather than lactate. The mitochondrial inhibitors, rotenone or rutamycin, did not change the amount of pyruvate that was converted to metabolites other than lactate, or L-acetylcarnitine, or both. Pyruvate-supported State 3 respiration was linear only if L-carnitine, or malate, or both, were added to the incubation medium. Added malate was necessary to produce a rapid State 3 respiratory rate and was also required for significant respiratory activity in the presence of rotenone or rutamycin. From cells metabolizing [2-14C]pyruvate (1.4 mM), 14C-labeled acid-extractable metabolites were separated by ion exchange column chromatography. All of the [2-14C]pyruvate (+/-5%) used was recovered in 14C-labeled metabolites and 14CO2. In the presence of malate, citrate accumulation was significant, and was always large in comparison to flux through the citric acid cycle. Glutamate, beta-hydroxybutyrate, acetoacetate, fumarate, aspartate, and alpha-ketoglutarate did not accumulate in significant amounts. Some 14C-labeled succinate was produced but only in the presence of malate. Alkaline hydrolysis of a fraction containing carnitine esters yielded acetate and a compound tentatively identified as beta-hydroxybutyrate or lactate. As in intact cells, intramitochondrial lactate dehydrogenase competes successfully with the electron transport system for the NADH generated by pyruvate metabolism. The role of lactate and L-carnitine, and conclusions suggested by the accumulation of certain metabolites are discussed in relation to control of citric acid cycle activity.
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PMID:Mitochondrial metabolism of pyruvate in bovine spermatozoa. 83 19

Creatine kinase isoenzymes (CK = ATP: creatine N-phosphoryl transferase, EC 2.7.3.2) were localized in situ in cryosections of intact sarcomeric muscle by immunocytochemical staining. Similar to cardiac muscle, spermatozoa and photoreceptor cells, mitochondrial-type CK (Mi-CK) localization in skeletal muscle was also restricted to mitochondria. Besides the well-documented localization of muscle-type (M-CK) at the M-line and at the sarcoplasmic reticulum, surprisingly, most of the sarcoplasmic M-CK was also highly compartmentalized and was mainly confined to the I-band. The localization of M-CK at the I-band coincided with that of adenylate kinase and aldolase. In intact muscle, the diffusion equilibrium decisively favours occupancy by all three enzymes of the I-band, with the acto-myosin overlap region of the A-band acting as a molecular sieve, excluding to a large extent all three enzymes from the acto-myosin overlap region. This indicates that in intact muscle, this region of the A-band may be less accessible in vivo to soluble, sarcoplasmic enzymes than thought before. If muscle were permeabilized by chemical skinning before fixation, I-band CK, as well as aldolase and adenylate kinase, were solubilized and disappeared from the myofibrils, but the fraction of M-CK which was specifically associated with the M-line remained bound to the myofibrils. Implications of these findings are discussed with respect to the functional coupling of I-band-CK with glycolysis, to the formation of large multienzyme complexes of glycolytic enzymes with CK and to the supply of energy for muscle contraction in general.
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PMID:In situ compartmentation of creatine kinase in intact sarcomeric muscle: the acto-myosin overlap zone as a molecular sieve. 140 Oct 38

The anticancer and immunosuppressive drug cyclophosphamide is extensively used in clinical practice and is known to alter fertility in man. We showed previously that treatment of male rats with low daily doses of cyclophosphamide over a 9-week period caused fetal malformations, a high rate of postimplantation loss and affected epididymal and sperm histology. In the present study, five biochemical measures of epididymal function were used to characterize further the effects of cyclophosphamide on the epididymis. For 1, 3, 6, or 9 weeks, adult Sprague-Dawley rats were gavage-fed daily with saline (control), 5.1 (low dose), or 6.8 (high dose) mg/kg of cyclophosphamide. The specific activities of the two glycolytic enzymes aldolase and lactate dehydrogenase (LDH), the mitochondrial enzyme succinate dehydrogenase, the cytosolic enzyme carnitine acetyltransferase and the lysosomal enzyme acid phosphatase were determined in cytosolic and mitochondrial subcellular fractions from four segments of the epididymis. Cyclophosphamide caused decreases in protein concentrations in all segments of the epididymis only after 6 weeks of treatment with the high dose. The specific activities of aldolase, LDH and succinate dehydrogenase did not differ from control with respect to dose or duration of treatment. In contrast, there were significant effects of cyclophosphamide on carnitine acetyltransferase and acid phosphatase specific activity. After 1 week of treatment, there was a transient dose-related decrease in the specific activity of carnitine acetyltransferase, which was most striking for the corpus epididymidis (76% of control), but which did not differ from control after 3, 6, and 9 weeks. After 6 weeks of treatment with the high dose of cyclophosphamide, carnitine acetyltransferase specific activity in the initial segment and the corpus epididymidis was elevated to 165 and 140%, respectively, as compared with the 1-week high dose values. The specific activity of acid phosphatase did not differ from control after 1 and 9 weeks of treatment. At 3 and 6 weeks, however, there was a dose-related increase in acid phosphatase specific activity for all regions of the epididymis that was most marked in the cauda after the 6-week treatment (140% of control). Therefore, low dose, daily treatment of male rats with cyclophosphamide not only alters specific enzymes in specific segments of the epididymis, but acts in a dose- and time-dependent manner. It is possible that these changes could be mediated by direct, toxic effects of the drug on the epithelium or be secondary to alterations in the spermatozoa as a result of the treatment.
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PMID:Effects of cyclophosphamide on selected cytosolic and mitochondrial enzymes in the epididymis of the rat. 338 43

Assay of maximal activities of 11 glycolytic enzymes in cell-free buffalo sperm extracts showed that hexokinase, phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase had the lowest activities, suggesting regulation of fructolysis at steps catalysed by these enzymes. The ratios of glyceraldehyde-3-phosphate dehydrogenase/phosphofructokinase (0.67) and phosphoglycerate kinase/phosphofructokinase (4.60) are typical of cells exhibiting high Pasteur effect (50% for ejaculated buffalo spermatozoa). The regulatory nature of phosphofructokinase was shown through its modulation by ATP, AMP and inorganic phosphate. The determination of fructolytic intermediates and cofactors and calculation of mass action ratios for each enzymic step revealed that hexokinase, phosphofructokinase, fructose-biphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase and pyruvate kinase catalysed reactions far removed from the equilibrium. A regulatory role by glyceraldehyde-3-phosphate dehydrogenase appeared to be most likely because triosephosphates and inorganic phosphate accumulated more under anaerobic than under aerobic conditions.
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PMID:REgulation of glycolysis/fructolysis in buffalo spermatozoa. 645 53

The nature of the association of the glycolytic enzyme, aldolase, with mature bovine spermatozoa was investigated in comparison with bovine muscle aldolase. Bovine muscle aldolase (BMA) was optimally solubilized by 0.1% deoxycholate and purified to homogeneity by ammonium sulfate fractionation, gel-filtration chromatography and phosphocellulose affinity chromatography. Bovine sperm aldolase (BSpA) was solubilized with optimal specific activity by 0.1% Triton X-100 and 50 mM sodium phosphate. Soluble BSpA represented 10% of the total aldolase activity in bovine spermatozoa. It could not be purified from other sperm components by standard procedures. The association of BSpA with sperm components involved noncovalent, ionic and hydrophobic interactions and did not involve disulfide bonds or covalent bonds. The stability of the BSpA association with intracellular substructure implies that very specific multiple-ligand bonding is involved. The Km for fructose-1-phosphate (1.7 X 10(-1) M) was higher and the activity with fructose-1,6-biphosphate relative to fructose-1-phosphate (Vmax FBP/Vmax F-1-P = 0.038) was much lower than for either liver or muscle aldolase. Kinetic analysis and subcellular associations indicated that sperm aldolase is different from other isozymes of aldolase.
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PMID:Association of bovine sperm aldolase with sperm subcellular components. 646 57

Senescence-accelerated mouse (SAM) strains constitute a model of accelerated senescence coupled with a short lifespan and the early development of various age-related disorders. To identify differential gene expression in testes between senescence-accelerated SAMP1 and control SAMR1 mice, we performed suppression subtractive hybridization. We observed that the expression of three genes related to cell proliferation (myosin regulatory light chain B, aldolase 1A isoform, and cytochrome c oxidase subunit VIc) were upregulated and four genes implicated in spermatogenesis were downregulated in SAMP1 mice. Asb-8, a member of ankyrin repeat-containing proteins, was abundantly expressed in the testes and downregulated in SAMP1. The other three downregulated genes (germ cell-specific gene 1, T-complex polypeptide 1b, and activator of cAMP responsive element modulator in testis) have been reported to regulate late-stage spermatogenesis. These gene expression profiles might explain the findings of early testicular maturation and rapid decline in the ability to produce spermatozoa with advancing age in SAMP1 mice.
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PMID:Identification of differentially expressed genes in senescence-accelerated mouse testes by suppression subtractive hybridization analysis. 1733 56