Triosephosphate metabolism by mature boar spermatozoa

1997 ◽  
Vol 9 (6) ◽  
pp. 577 ◽  
Author(s):  
A. R. Jones
Keyword(s):  
Glycolytic Pathway ◽  
Dihydroxyacetone Phosphate ◽  
Glycolytic Intermediates ◽  
Boar Sperm ◽  
Equilibrium Concentrations ◽  
Fructose 1,6 Bisphosphate ◽  
Boar Spermatozoa

Boar sperm rapidly interconverted dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, produced fructose-1,6-bisphosphate, approximately equilibrium concentrations of fructose 6-phosphate and glucose 6-phosphate but not glycerol or glycerol 3-phosphate. In the presence of 3-chloro-1-hydroxypropanone, an inhibitor of stage 2 of the glycolytic pathway, the triosephosphates were metabolized faster, produced less fructose-1,6-bisphosphate, fructose 6-phosphate and glucose 6-phosphate, but not glycerol or glycerol 3-phosphate. This suggests that these cells may have the capacity to convert glycolytic intermediates into a storage metabolite to conserve carbon atoms for the eventual synthesis of lactate.

Inhibition of glyceraldehyde 3-phosphate dehydrogenase in boar spermatozoa by bromohydroxypropanone

1995 ◽  
Vol 7 (1) ◽  
pp. 107 ◽  
Author(s):  
LM Porter ◽  
AR Jones
Keyword(s):  
Carbonyl Compound ◽  
Energy Charge ◽  
Mature Sperm ◽  
Dihydroxyacetone Phosphate ◽  
Epididymal Sperm ◽  
Charge Potential ◽  
Fructose 1,6 Bisphosphate ◽  
Boar Spermatozoa

In the presence of 3-bromo-1-hydroxypropanone (BOP), cauda epididymal sperm obtained from mature boars produced a carbonyl compound which is assumed to be (S)-3-bromolactaldehyde. Glyceraldehyde 3-phosphate dehydrogenase was rapidly inhibited which resulted in the accumulation of dihydroxyacetone phosphate and fructose-1,6-bisphosphate, and no accumulation of lactate when fructose was the substrate. The energy charge potential of the cells declined in the presence of BOP when either fructose or glycerol were substrates. It is suggested that BOP is transformed into (S)-3-bromolactaldehyde, which is the actual inhibitor of glyceraldehyde 3-phosphate dehydrogenase, thus demonstrating BOP to be the first brominated chemical to have an anti-glycolytic action on mature sperm in vitro.

Control of glycolysis in mature boar spermatozoa: effect of pH in vitro

2004 ◽  
Vol 16 (3) ◽  
pp. 319 ◽  
Author(s):  
A. R. Jones ◽  
D. E. Connor
Keyword(s):  
Glycolytic Pathway ◽  
Cytoplasmic Ph ◽  
Effect Of Ph ◽  
Boar Sperm ◽  
Boar Spermatozoa

The glycolytic pathway in boar sperm is sensitive to pH, which decreases as lactate is produced from either glucose or fructose in vitro. The build up of lactate appears to be due to the saturation of mitochondrial lactate transporters, which causes the cytoplasmic pH to fall. Phosphofructokinase has been shown to be sensitive to this drop in pH rather than to the build up of lactate ions or ATP, thereby controlling the rate of glycolysis in vitro.

Metabolism of fructose-1,6-bisphosphate by mature boar spermatozoa

1991 ◽  
Vol 3 (5) ◽  
pp. 609 ◽  
Author(s):  
AR Jones ◽  
MD Montague
Keyword(s):  
Carbon Dioxide ◽  
Dihydroxyacetone Phosphate ◽  
High Concentration ◽  
Atp Levels ◽  
High Concentrations ◽  
Fructose 1,6 Bisphosphate ◽  
Boar Spermatozoa

Mature epididymal boar spermatozoa converted glucose and fructose to carbon dioxide and lactate and maintained high concentrations of ATP. In the presence of (S)-alpha-chlorohydrin these processes were inhibited and there was an accumulation of fructose-1,6-bisphosphate and dihydroxyacetone phosphate. With fructose-1,6-bisphosphate as the substrate, the concentration of ATP was maintained, carbon dioxide was evolved and dihydroxyacetone phosphate accumulated. Cells pre-incubated with (S)-alpha-chlorohydrin did not maintain ATP levels, evolved less carbon dioxide and produced dihydroxyacetone phosphate. Assays of incubates in which fructose-1,6-bisphosphate was used as the substrate showed the presence of equilibrium quantities of fructose-6-phosphate and glucose-6-phosphate which were not detected when either fructose or glucose were used as substrates. [14C]Fructose and [14C]glucose were not produced from [14C]fructose-1,6-bisphosphate in spermatozoal incubates which had or had not been pre-incubated with (S)-alpha-chlorohydrin. Evidence is presented that a high concentration of fructose-1,6-bisphosphate leads to the formation of fructose-6-phosphate and glucose-6-phosphate but not of fructose and/or glucose.

scholarly journals Triosephosphate isomerase deficiency: consequences of an inherited mutation at mRNA, protein and metabolic levels

2005 ◽  
Vol 392 (3) ◽  
pp. 675-683 ◽  
Author(s):  
Judit Oláh ◽  
Ferenc Orosz ◽  
László G. Puskás ◽  
László Hackler ◽  
Margit Horányi ◽  
...  
Keyword(s):  
Steady State ◽  
Triosephosphate Isomerase ◽  
Specific Activity ◽  
Energy State ◽  
Dihydroxyacetone Phosphate ◽  
Peptidase Activity ◽  
Mrna Levels ◽  
Regulatory Enzymes ◽  
Computational Data ◽  
Fructose 1,6 Bisphosphate

Triosephosphate isomerase (TPI) deficiency is a unique glycolytic enzymopathy coupled with neurodegeneration. Two Hungarian compound heterozygote brothers inherited the same TPI mutations (F240L and E145Stop), but only the younger one suffers from neurodegeneration. In the present study, we determined the kinetic parameters of key glycolytic enzymes including the mutant TPI for rational modelling of erythrocyte glycolysis. We found that a low TPI activity in the mutant cells (lower than predicted from the protein level and specific activity of the purified recombinant enzyme) is coupled with an increase in the activities of glycolytic kinases. The modelling rendered it possible to establish the steady-state flux of the glycolysis and metabolite concentrations, which was not possible experimentally due to the inactivation of the mutant TPI and other enzymes during the pre-steady state. Our results showed that the flux was 2.5-fold higher and the concentration of DHAP (dihydroxyacetone phosphate) and fructose 1,6-bisphosphate increased 40- and 5-fold respectively in the erythrocytes of the patient compared with the control. Although the rapid equilibration of triosephosphates is not achieved, the energy state of the cells is not ‘sick’ due to the activation of key regulatory enzymes. In lymphocytes of the two brothers, the TPI activity was also lower (20%) than that of controls; however, the remaining activity was high enough to maintain the rapid equilibration of triosephosphates; consequently, no accumulation of DHAP occurs, as judged by our experimental and computational data. Interestingly, we found significant differences in the mRNA levels of the brothers for TPI and some other, apparently unrelated, proteins. One of them is the prolyl oligopeptidase, the activity decrease of which has been reported in well-characterized neurodegenerative diseases. We found that the peptidase activity of the affected brother was reduced by 30% compared with that of his neurologically intact brother.

scholarly journals Fructose 1,6-bisphosphate aldolase from rabbit muscle. The isomerization of the enzyme-dihydroxyacetone phosphate complex

1977 ◽  
Vol 167 (2) ◽  
pp. 361-366 ◽  
Author(s):  
E Grazi ◽  
M Blanzieri
Keyword(s):  
Competitive Inhibitor ◽  
Dihydroxyacetone Phosphate ◽  
Rabbit Muscle ◽  
Keto Form ◽  
First Order ◽  
Phosphate Complex ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
Dead End ◽  
Fructose 1,6 Bisphosphate

The formation and dissociation of the aldolase-dihydroxyacetone phosphate complex were studied by following changes in A240 [Topper, Mehler & Bloom (1957), Science 126, 1287-1289]. It was shown that the enzyme-substrate complex (ES) slowly isomerizes according to the following reaction: (formula: see text) the two first-order rate constants for the isomerization step being k+2 = 1.3s-1 and k-2 = 0.7s-1 at 20 degrees C and pH 7.5. The dissociation of the ES complex was provoked by the addition of the competitive inhibitor hexitol 1,6-bisphosphate. At 20 degrees C and pH 7.5, k+1 was 4.7 X 10(6)M-1-S-1 and k-1 was 30s-1. Both the ES and the ES* complexes react rapidly with 1.7 mM-glyceraldehyde 3-phosphate, the reaction being practically complete in 40 ms. This shows that the ES* complex is not a dead-end complex. Evidence was also provided that aldolase binds and utilizes only the keto form of dihydroxyacetone phosphate.

scholarly journals Inhibition of Fructolysis in Boar Spermatozoa by the Male Antifertility Agent (S)-a-Chlorohydrin

1982 ◽  
Vol 35 (6) ◽  
pp. 595 ◽  
Author(s):  
Denise Stevenson ◽  
A RJones
Keyword(s):  
Oxidative Metabolism ◽  
Inhibitory Activity ◽  
Energy Charge ◽  
Substrate Level Phosphorylation ◽  
Charge Potential ◽  
Substrate Level ◽  
Glyceraldehydephosphate Dehydrogenase ◽  
Fructose 1,6 Bisphosphate ◽  
Boar Spermatozoa

The (S)-isomer of the male antifertility agent IX-chlorohydrin strongly inhibited the oxidative metabolism of fructose by boar spermatozoa in vitro. The result of this action, which has been deduced to be an inhibition of glyceraldehydephosphate dehydrogenase, caused an accumulation of fructose- 1,6-bisphosphate and the triosephosphates, and a decrease in substrate-level phosphorylation with a concomitant lowering of the energy charge potential of the spermatozoa. The (R)-isomer of IX-chlorohydrin had no inhibitory activity on fructolysis.

75 GLUCOSE CONCENTRATION OF FREEZING EXTENDER MODULATES THE TYROSINE PHOSPHORYLATION PATTERN OF FROZEN-THAWED BOAR SPERMATOZOA

2009 ◽  
Vol 21 (1) ◽  
pp. 138
Author(s):  
J. E. Rodríguez-Gil ◽  
M. Hernández ◽  
M. M. Rivera ◽  
L. Ramió-Lluch ◽  
J. Ballester ◽  
...  
Keyword(s):  
Protein Phosphorylation ◽  
Tyrosine Phosphorylation ◽  
Glucose Concentration ◽  
Egg Yolk ◽  
Freezing And Thawing ◽  
Precise Control ◽  
Boar Sperm ◽  
Phosphorylation Pattern ◽  
Thawing Process ◽  
Boar Spermatozoa

The optimization of freezing extenders is an essential issue for enhancing boar sperm cryosurvival. The aim of the present study was to disclose the role of glucose concentration of freezing extender on the metabolic activity of frozen–thawed spermatozoa. To achieve it, pooled sperm-rich ejaculate fractions from 5 mature and fertile boars (3 ejaculates per boar) were collected using the gloved-hand method. After centrifugation (2400g for 3 min), the sperm pellet was split into 7 aliquots. The aliquots were diluted to a final concentration of 1 × 109 sperm mL–1, in a Tris-citric extender supplemented with 20% egg-yolk, 3% glycerol, and 0, 0.05, 2, 4, 10, 55, or 185 mm glucose. All the extenders were adjusted to a pH of 6.8 and 310 mOsm kg–1 to avoid osmolarity effects. Extended semen samples were dispensed into 0.5-mL straws, and frozen in a programmable cell freezer at 20°C min–1. Thawing was carried out in a water bath at 37°C for 20 s. Afterward, an analysis of protein phosphorylation in tyrosine residues was carried out through bi-dimensional electrophoresis followed by a Western blot analysis. This analysis indicated that sperm samples frozen in extenders without glucose showed specific changes in the tyrosine phosphorylation pattern compared with fresh sperm. Furthermore, the addition of glucose in increasing concentrations to the freezing extender was accompanied by a concentration-dependent decrease in the overall tyrosine phosphorylation pattern, especially in proteins with a molecular weight ranging from 150 to 200 kDa and an acidic isoelectric point (pI). The maximal decrease was observed in spermatozoa frozen in the extender containing 185 mm glucose, in which an additional decrease in the tyrosine phosphorylation of proteins ranging from 60 to 80 kDa, and a basic pI was also observed. These results suggest that glucose is a modulator in the resistance of boar sperm to support freezing and thawing process, because the precise protein phosphorylation pattern of spermatozoa is directly linked to their functional status. In this way, a precise control of the glucose concentration of the freezing extender would be required to improve boar sperm cryoresistance. Supported by CICYT (AGL2005-00760 and AGL2004-04756-C02-02/GAN), Madrid and GERM (04543/07), Murcia, Spain.

scholarly journals Erythrocyte glycolysis and its marked alterations by muscular exercise in type VII glycogenosis

Blood ◽  
1988 ◽  
Vol 71 (4) ◽  
pp. 1130-1134 ◽  
Author(s):  
T Shimizu ◽  
N Kono ◽  
H Kiyokawa ◽  
Y Yamada ◽  
N Hara ◽  
...  
Keyword(s):  
Bed Rest ◽  
Normal Subjects ◽  
Dihydroxyacetone Phosphate ◽  
Crossover Point ◽  
Control Value ◽  
Myogenic Factors ◽  
Fructose 1,6 Bisphosphate ◽  
2,3 Dpg ◽  
Ergometric Exercise

Abstract Levels of erythrocyte glycolytic intermediates after the phosphofructokinase (PFK) step, including 2,3-bisphosphoglycerate (2,3- DPG), were decreased at rest in patients from separate families with type VII glycogenosis. The concentration of 2,3-DPG was about half of the normal control value during a period of unrestricted daily activity but was further decreased to one third of normal after a one-day bed rest. Mild ergometric exercise rapidly increased the levels of fructose- 1,6-bisphosphate, dihydroxyacetone phosphate plus glyceraldehyde-3- phosphate, and 2,3-DPG in patients' circulating erythrocytes but did not in those of normal subjects. This indicated that a crossover point at the PFK step in glycolysis disappeared after physical exercise and, consequently, the 2,3-DPG concentration, which had decreased because of blockage of the PFK step, was restored considerably. This apparently exercise-related alteration in intermediary metabolism at the beginning of glycolysis was reproduced in vitro by incubating normal erythrocytes in the presence of inosine or ammonia, both of which have increased levels in circulating blood during and after exercise in this disorder. We conclude that physical activity in addition to a genetic deficiency in erythrocyte PFK affects glycolysis in erythrocytes in type VII glycogenosis and that myogenic factors released from exercising muscles may be responsible for this change.

Effect of acidosis on skeletal muscle metabolism with and without propranolol

1990 ◽  
Vol 68 (7) ◽  
pp. 870-876
Author(s):  
J. K. Barclay ◽  
T. E. Graham ◽  
B. R. Wolfe ◽  
J. Van Duk ◽  
B. A. Wilson
Keyword(s):  
Skeletal Muscle ◽  
Muscle Metabolism ◽  
Inhibitory Effect ◽  
Metabolic Effects ◽  
Dihydroxyacetone Phosphate ◽  
Glycerol Phosphate ◽  
Muscle Lactate ◽  
Skeletal Muscle Metabolism ◽  
Glycogen Concentration ◽  
Glycolytic Intermediates

Does the stimulatory effect of circulating catecholamines counteract the inhibitory effect of acidosis on skeletal muscle metabolism? To investigate this possibility, we studied gastrocnemii in dogs breathing either air (n = 10) or 4% carbon dioxide in air (n = 10) at rest and during contractions. In five dogs from each group, we infused propranolol into the arterial supply of the right and left muscles for 40 min. After 30 min of infusion, the left muscle was stimulated at 3 Hz for 10 min. During the 10th min of contractions, we removed and froze both muscles in liquid nitrogen. Oxygen uptake and blood flow to the left muscle prior to or during stimulation was not affected by acidosis either with or without propranolol. Glycogen concentration in resting muscle was unaffected by acidosis with or without propranolol. There was an acidosis related decrease of approximately 50% in the glycolytic intermediates (glucose 6-phosphate, fructose 1,6-diphosphate, α-glycerol phosphate, and dihydroxyacetone phosphate) in unstimulated muscles without β-blockade. At rest, acidosis decreased muscle lactate by 50% with and 64% without propranolol, but lactate release was decreased only with acidosis without propranolol (1.4–0.1 μmol/kg∙s). Acidosis without propranolol had no effect on the changes in glycogen concentration or the change in the concentration of glycolytic intermediates resulting from contractions. In β-blocked muscle, the difference between stimulated and unstimulated concentrations of glycogen and glycolytic intermediates including lactate was 20–50% smaller with acidosis. Thus, with β-blockade, the acidotic effects at rest disappeared and an inhibition of the metabolic adjustment to contractions appeared, indicating that circulating catecholamines do modify some metabolic effects of acidosis.Key words: oxidative muscle, glycogen, lactate efflux, glycolytic intermediates, β-blockade.

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