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PubMedDate not supplied

Immobilization of lactate dehydrogenase on tetraethylorthosilicate-derived sol-gel films for application to lactate biosensor.

Tetraethylorthosilicate (TEOS)-derived sol-gel films were utilized for the immobilization of lactate dehydrogenase (LDH) by physical adsorption and sol-gel/LDH/sol-gel sandwich configuration. An attempt was made to ascertain the optimum pH and temperature for the immobilized LDH. It was shown that TEOS-derived sol-gel films containing physically adsorbed LDH exhibited linearity from 0.5 to 4 mM, whereas those containing LDH in sandwich configuration showed linearity from 0.5 to 3 mM L-lactate. These sol-gel films, immobilized with LDH, were found to be stable for about 4 weeks at 4-10 degrees C.

Adsorption↗

PubMed1990

Serum lactate dehydrogenase, alpha-hydroxybutyrate dehydrogenase and ratio of alpha-hydroxybutyrate dehydrogenase to lactate dehydrogenase in testicular tumours.

Serum levels of Lactate Dehydrogenase (LDH), alpha-Hydroxybutyrate Dehydrogenase (HBDH) and the relative ratio of alpha-Hydroxybutyrate Dehydrogenase to Lactate Dehydrogenase (HBDH/LDH) were determined in 51 cases of histologically proved testicular germ cell tumors and 40 healthy controls. Serum LDH and HBDH levels were found to be raised in both seminomatous and non-seminomatous germ cell tumors. The ratio of HBDH/LDH was found to be statistically significant in seminomas and insignificant in non-seminomatous germ cell tumors. Furthermore, the levels of LDH and HBDH showed a fall, following treatment indicating response to therapy. Serum LDH and HBDH could both be used as tumor markers in the diagnosis of testicular germ cell tumors as well as prognostic indicators in monitoring therapy, HBDH, being more specific in monitoring therapy as compared to serum LDH.

Adolescent↗

PubMed1990

[Post-cesarean section maternal lactation: lactational and neonatal follow-up].

A clinical lacteal, neonatal, following up, was done in 25 puerperal women, post-cesarean section, who had selected breast feeding for their child since their prenatal control. It was concluded that adequate assessorship about lactation during prenatal consultation, positively modifies maternal attitudes towards natural feeding; and that it is also possible and convenient to introduce in the perinatology team's practice the support to lactation with special emphasis in hospital stay after cesarean section and subsequent consultation, for adequate surveillance of post-operative evolution, and control of the healthy child. In this manner, it is possible to orientate and encourage recent puerperae and to verify newborn's optimal growth when fed with this natural method.

Breast Feeding↗

PubMed1989

Use of purified lyophilized human lactate dehydrogenase isoenzyme 5 in a study of measuring lactate dehydrogenase activity.

We examined the stability of human lactate dehydrogenase (EC 1.1.1.27) isoenzyme 5--purified to a specific activity of about 400 kU/g--when lyophilized in a buffered, stabilized matrix of bovine albumin. This isoenzyme was prepared with a final activity of about 500 U/L and stored at -20, 4, 20, 37, and 56 degrees C for as long as six months. This isoenzyme decayed with approximate first-order kinetics, with an estimated half-life at -20 degrees C of about 475 years. Stability of reconstituted samples stored at 20 or 4 degrees C was poor, suggesting that the reconstituted material should be used without delay; material stored at -20 degrees C showed excellent stability for 15 days. We propose that such preparations might be further investigated as standards for use in electrophoresis of lactate dehydrogenase isoenzymes.

Enzyme Stability↗

PubMed1983

Mitochondrial NAD, L-lactate dehydrogenase and NAD, D-lactate dehydrogenase in the yeast Saccharomyces cerevisiae.

Mitochondrial NAD-linked L- and D-lactate dehydrogenase activities have been found in the yeast Saccharomyces cerevisiae grown at high (3%) but were absent at low (0.6%) glucose concentrations. The inhibition of mitochondrial protein synthesis by chloramphenicol and of primary respiration by antimycin A determines the appearance of the two activities even at low (0.6%) glucose concentration. Two respiratory deficient strains belonging respectively to the mit- class (which maintains mitochondrial protein synthesis) and to the rho- class (which loses mitochondrial protein synthesis) display the activities even at low (0.6%) glucose concentration. L- and D-lactate have been detected in the growth medium when the cultures had been undertaken at high glucose concentrations, but were absent at low glucose concentrations.

Anaerobiosis↗

PubMed1981

[Variations in plasma components in lactating mares at late pregnancy-early lactation (author's transl)].

In an experiment comparing pregnant then lactating mares with dry non-pregnant mares, the changes in plasma components were studied as indicators of the metabolic utilization of energy (glucose, non-esterified fatty acids, beta-hydroxybutyrate), nitrogen (urea, proteins) or minerals (calcium, phosphorus, magnesium). The mares were fed daily 2 kg concentrate and hay ad libitum. Beta-hydroxybutyrate, magnesium and to a lesser extent glucose were the only constituents whose levels were affected within the period starting one month before and ending one month after foaling. The increase in food intake between late pregnancy and early lactation may be explained by an increase in nutrient requirements, since plasmatic levels of non-esterified fatty acids and urea, known to be indicators of body lipids mobilization and nitrogen status respectively, remained constant.

3-Hydroxybutyric Acid↗

PubMed1996

The effect of erythropoietin on lactate, pyruvate and excess lactate under physical exercise in dialysis patients.

To investigate EPO-induced increase of hemoglobin on energy metabolism plasma concentrations of lactate (L), pyruvate (P) and excess lactate (XL) were determined in ten dialysis patients at rest, immediately after 6 minutes of ergometric exercise as well as after recovery for 15 and 30 min. The investigations were performed before EPO-therapy at a mean Hb = 7.5 +/- 0.9 g/dl and under EPO-therapy at a mean Hb = 10.0 +/- 0.6 g/dl and at a mean Hb = 11.9 +/- 0.8 g/dl. Ten healthy subjects were subjected to the same investigation at Hb = 14.7 +/- 1.1 g/dl. There was a significant rise of L and XL in all patient groups under ergometric exercise. The increase of hemoglobin from 7.5 g/dl to 10.0 g/dl led to significantly (p < 0.01) lower L and XL concentrations immediately after exercise (L = 4.62 vs 3.23 mmol/l, XL = 2.37 vs 1.38 mmol/l). The further decrease of the mean L and XL values (L = 2.88 mmol/l, XL = 1.05 mmol/l) associated with the rise of hemoglobin to 11.9 g/dl could not be confirmed statistically. In contrast to all patient groups, there was no significant rise in XL in the healthy control subjects under physical exercise. The present results make it evident that patients with renal anemia react even to light physical exercise with pronounced tissue hypoxia in contrast to healthy subjects. The increase of the hemoglobin content under the EPO-therapy leads to a marked reduction of the tissue hypoxia and consequently of anaerobic energy production. A further rise of the hemoglobin content above and beyond 10.5 g/dl will have an additional positive effect on oxygen supply only in occasional cases. The comparison with healthy subjects shows that despite a very large degree of normalization of the hemoglobin content, no normalization of energy metabolism can be attained.

Anaerobic Threshold↗

PubMed1999

Blood glucose responses in humans mirror lactate responses for individual anaerobic threshold and for lactate minimum in track tests.

The equilibrium point between blood lactate production and removal (La-(min)) and the individual anaerobic threshold (IAT) protocols have been used to evaluate exercise. During progressive exercise, blood lactate [La-]b, catecholamine and cortisol concentrations, show exponential increases at upper anaerobic threshold intensities. Since these hormones enhance blood glucose concentrations [Glc]b, this study investigated the [Glc] and [La-]b responses during incremental tests and the possibility of considering the individual glucose threshold (IGT) and glucose minimum (Glc(min)) in addition to IAT and La-(min) in evaluating exercise. A group of 15 male endurance runners ran in four tests on the track 3000 m run (v3km); IAT and IGT - 8 x 800 m runs at velocities between 84% and 102% of v3km; La-(min) and Glc(min) - after lactic acidosis induced by a 500-m sprint, the subjects ran 6 x 800 m at intensities between 87% and 97% of v3km; endurance test (ET) - 30 min at the velocity of IAT. Capillary blood (25 microl) was collected for [La-]b and [Glc]b measurements. The IAT and IGT were determined by [La-]b and [Glc]b kinetics during the second test. The La-(min) and Glc(min) were determined considering the lowest [La-] and [Glc]b during the third test. No differences were observed (P < 0.05) and high correlations were obtained between the velocities at IAT [283 (SD 19) and IGT 281 (SD 21) m. x min(-1); r = 0.096; P < 0.001] and between La-(min) [285 (SD 21)] and Glc(min) [287 (SD 20) m. x min(-1) r = 0.77; P < 0.05]. During ET, the [La-]b reached 5.0 (SD 1.1) and 5.3 (SD 1.0) mmol x l(-1) at 20 and 30 min, respectively (P > 0.05). We concluded that for these subjects it was possible to evaluate the aerobic capacity by IGT and Glc(min) as well as by IAT and La-(min).

Adult↗

PubMed2026

Proteomics combined with single-cell sequencing reveals key genes and computational lead compound related to ligamentum flavum hypertrophy, lactate metabolism and lactate modification.

Ligamentum flavum hypertrophy (LFH) is a hallmark pathological feature of lumbar spinal stenosis; however, its underlying molecular mechanisms remain incompletely understood. Lactate metabolism and related lactylation modifications have emerged as critical links between cellular metabolism and epigenetic regulation, with established roles in various fibrotic and inflammatory diseases. Nevertheless, the specific contribution of lactylation to LFH pathogenesis remains unexplored. In this study, we integrated proteomic profiling of ligamentum flavum tissues with single-cell transcriptomic data to identify differentially expressed proteins associated with LFH. Cross-referencing these genes with genes involved in lactate metabolism and lactylation yielded 16 candidate genes. Through functional enrichment analysis, protein-protein interaction network construction, and GraphBAN model prediction, we identified five hub genes (NDUFS2, HMOX1, SPR, FABP5, and PFKP) and two potential lead compounds (ZINC000014879975 and ZINC000242437513). Molecular docking analysis confirmed favorable binding affinities between these compounds, suggesting that they may serve as potential lead compounds worthy of further experimental investigation. Single-cell analysis further revealed that macrophages occupy a central position in the LFH microenvironment, resulting in pronounced metabolic reprogramming and remodeling of intercellular communication networks, particularly via the MIF-CD74/CD44 axis, under pathological conditions.

Proteomics↗

PubMed1996

Peak blood lactate and blood lactate vs. workload during acclimatization to 5,050 m and in deacclimatization.

Peak blood lactate ([Labl]peak) and blood lactate concentration ([Labl]) vs. workload (W) relationships during acclimatization to altitude and in the deacclimatization were evaluated in 10 Caucasian lowlanders at sea level (SL0); after approximately 1 wk (Alt1wk), 3 wk (Alt3wk), and 5 wk (Alt5wk) at 5,050 m; and weekly during the first 5 wk after return to sea level (SL1wk-SL5wk). Incremental bicycle ergometer exercises (30 W added every 4 min up to exhaustion) were performed. At Alt1wk and at Alt5wk, the experiments were repeated in hypobaric normoxia (Alt1wk-O2 and Alt5wk-O2). [Labl] was determined at rest and during the last approximately 30 s of each W. [Labl]peak was taken as the highest [Labl] during recovery. Acid-base status (pH and concentration of HCO-3 in arterialized capillary blood) was determined at rest. Mean [Labl]peak values were 11.5 (SL0), 8.0 (Alt1wk), 6.4 (Alt3wk), 6.3 (Alt5wk), 8.0 (SL1wk), 9.4 (SL2wk), 10.8 (SL3wk), 11.3 (SL4wk), and 11.6 (SL5wk) mM. At Alt1wk-O2 and Alt5wk-O2, peak W increased, compared with Alt1wk and Alt5wk, whereas no changes were observed for [Labl]peak. [Labl] vs. W was shifted to the left (i.e., higher [Labl] values were found for the same W) at Alt1wk compared with SL0 and partially shifted back to the right (i.e., lower [Labl] values were found for the same W) at Alt3wk and Alt5wk. At Alt1wk-O2 and Alt5wk-O2, [Labl] vs. W values were superimposed on that at SL0. At SL1wk-SL5wk, [Labl] vs. W values were shifted to the right compared with that at SL0. At Alt1wk, a condition of respiratory alkalosis was found, which was only partially compensated for during acclimatization. At SL1wk, the acid-base status was back to normal. We conclude that 1) the reduced [Labl]peak at altitude is still present for 2-3 wk after return from altitude; is not attributable to reduced peak W nor to hypoxia per se, nor to a reduced buffer capacity; alternatively, it could be related to some central determinants of fatigue. 2) The [Labl] vs. W leftward shift at altitude was due to hypoxia per se. 3) The factor(s) responsible for the [Labl] vs. W partial rightward shift during acclimatization could still be effective during the first weeks after return to sea level.

Acclimatization↗

PubMed2003

Blood lactate disappearance dynamics in boys and men following exercise of similar and dissimilar peak-lactate concentrations.

Characteristically, children recover faster than adults from various types of exercise. The purpose of the present study was to explain the children's faster recovery, in part, by addressing lactate (La) removal and comparing La disappearance dynamics in the two age groups following exercise of both similar and dissimilar peak blood-lactate concentration values ([La]pk). The subjects were 14 prepubertal boys and 12 men of similar peak oxygen consumption, normalized for body mass. All subjects performed 30 s supra-maximal cycling (Wingate anaerobic test [WAnT]). [La]pk was 10.7 +/- 1.9 and 14.7 +/- 1.7 mmol x l(-1) for the boys and men, respectively (p < 0.001). The men were later retested in shortened versions of the WAnT so as to attain [La]pk values (10.5 +/- 0.7 mmol x l(-1)) comparable to those achieved by the boys. [La]pk lag time following the boys' standard WAnT was similar to that found in the men following the shortened WAnT (5.0 +/- 2.6 vs 5.7 +/- 1.3 min, respectively), but considerably shorter than that following the men's 30s-WAnT (7.6 +/- 2.1 min; p < 0.05). The La disappearance dynamics were closely matched between groups following the matched [La]pk WAnTs. [La] half-life was similar under all conditions (ca. 20 min). It is concluded that prepubertal boys are characterized by a lower [La]pk and a shorter time lag before reaching it, following 30-s supra-maximal cycling exercise. However, boys' La disappearance dynamics are not different from that of men.

Adolescent↗

PubMed1989

Prospective, randomized trial of hypertonic sodium lactate versus lactated Ringer's solution for burn shock resuscitation.

We prospectively randomized 51 adult burned patients on admission to study fluid, electrolyte, and physiologic parameters during burn resuscitation with the use of hypertonic saline (HSL, Na 250 mEq/L, 514 mOsm) or lactated Ringer's solution (LR, Na 130 mEq/L, 268 mOsm). Patients suffered at least 20% total body surface area burns (BSA); the mean BSA injury was 36.7% BSA, with a range of 20 to 74% BSA. All patients were admitted to our Burn Center within at least 12 hours of injury. Laboratory studies included frequent determinations of serum chemistries including osmolalities, and continuous 24-hour urine collections for electrolytes and osmolality determinations. Fluid requirements (cc/kg/% BSA), urine output (cc/kg/hr), sodium intake and excretion (mEq/kg/% BSA), serum and urine osmolality (mOsm/kg), serum creatinine (mg/dl), body weight (kg), and enteral intake (cc/24 hrs and calories/24 hrs) were analyzed for comparison at 24-hour intervals following burn injury. Using Student's t-test, significance was attributed to a p less than 0.05. Nonparametric methods were used to compare non-normalized data. Regression analysis was used to compare sodium intake (mEq/kg) and fluid intake (cc/kg) between the HSL and the LR groups in relation to % BSA. Our data show no advantage of HSL over conventional therapy with LR for burn resuscitation. We were not able to demonstrate decreased fluid requirements, improved tolerance of feedings, or decrease in per cent weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1977

[Determination of lactate with centrifugal analyser (Gemsaec) by lactate dehydrogenase in the presence of alanine aminotransferase].

An automated method for lactat determination on centrifugal analyser is described. The measurements have been done by end-point method during 300 seconds. A reagent blank is introduced in each run and its absorbance is deduced from those of the tests. The suitability of the method is assessed, particularly the sensitivity (detection limit) and the accuracy by checking the recovery. The results obtained by the automated and the manual method are well correlated.

Alanine Transaminase↗

PubMed2000

Lactate dehydrogenase A-dependent surface expression of immature thymocyte antigen-1: an implication for a novel trafficking function of lactate dehydrogenase-A during T cell development.

A possible involvement of lactate dehydrogenase A (LDHA) in the translocation of a thymic differentiation antigen, immature thymocyte antigen-1 (IMT-1), from cytoplasm to cell surface membrane during thymocyte differentiation is described. Transfection of cDNA for LDHA, but not LDHB, into EL4 cells, which expressed IMT-1 in the cytoplasm but not on the cell surface, induced the expression of IMT-1 on the cell surface. This translocation process seemed to be dependent on the translation of LDHA cDNA in EL4 cells, as well as the native structure of LDHA composing of coenzyme binding domain, catalysis domain, and subunit contact domain. Immunoprecipitation analysis revealed that LDHA could be co-precipitated with IMT-1 from the cell surface of EL4 cells that had been transfected with LDHA cDNA, suggesting that some of LDHA is associated with cell surface IMT-1 on the transfectants. Flow cytometry analysis of thymocyte subpopulations showed that some thymocytes at the CD4(-)CD8(-) double negative stage express both IMT-1 and LDHA on their surface. These data indicate that LDHA, in addition to its function in the metabolism in the glycolytic pathway, may have a novel function in the expression of a cell surface antigen during T cell development.

Animals↗

PubMed1994

The nucleotide and deduced amino-acid sequences of a cDNA encoding lactate dehydrogenase from Caenorhabditis elegans: the evolutionary relationships of lactate dehydrogenases from mammals, birds, amphibian, fish, nematode, plants, bacteria, mycoplasma, and plasmodium.

The nucleotide and deduced amino-acid sequences of a cDNA encoding L-lactate dehydrogenase (LDH) from nematode, Caenorhabditis elegans, were reported. This first invertebrate LDH sequence of 333 amino acids, including the initiation methionine, exhibits 63% identity with that of the most primitive vertebrate lamprey. The evolutionary relationships among 36 LDH isozymes from mammals, birds, amphibian, fish, nematode, plants, bacteria, mycoplasma and plasmodium were analyzed. The invertebrate nematode LDH is evolutionarily positioned between plant LDH and mammalian testicular LDH-C isozymes. The mammalian LDH-C isozyme appears to have arisen after the invertebrate LDH, but prior to the divergence of vertebrate LDH-A (muscle) and LDH-B (heart) isozymes as described previously.

Amino Acid Sequence↗

PubMed1994

Population screening of lactate dehydrogenase deficiencies in Fukuoka Prefecture in Japan and molecular characterization of three independent mutations in the lactate dehydrogenase-B(H) gene.

Screening for lactate dehydrogenase (LDH) subunit deficiencies was performed on 2880 blood samples from healthy individuals in the Fukuoka Prefecture in Japan by means of electrophoresis. The frequencies of heterozygotes with either LDH-A or LDH-B deficiency were found to be 0.104% at each locus. These estimated frequencies of either LDH-A or LDH-B deficiencies were slightly lower than, but not significantly different from, those found previously in Shizuoka Prefecture. The genetic mutations in individuals heterozygous for LDH-B deficiency were analyzed by the polymerase chain reaction and DNA conformation polymorphism. Abnormal migration patterns were observed in individuals heterozygous for LDH-B deficiency. Subsequent sequence determination of the mutant alleles revealed three novel mutations: an eight-base duplication in exon 3, a four-base duplication in exon 4, and a one-base deletion in exon 7 of the LDH-B gene. These three mutations result in frame-shift translation and premature termination. In addition, the mutations resulting in the duplication of eight or four nucleotides appear to cause a decrease in the levels of LDH-B mRNA.

Amino Acid Sequence↗

PubMed1981

Water balance of small lactating rodents--III. Estimates of milk production and water recycling in lactating Mus musculus under various water regimes.

1. The exchanges of water between lactating female and young Mus musculus were modelled on the computer. 2. The model was used to estimate rates of milk production and water recycling in various litter sizes under various water regimes by following the time course of injected tritiated water. 3. The high correlation between estimated rates of milk production and actual growth rates of young was taken to indicate that the method gave if not the actual rates of milk production a very constant proportion of it. 4. Approximately 50% of the water secreted in milk is returned to the mother by recycling.

Animals↗

PubMed1985

Effects of training at and above the lactate threshold on the lactate threshold and maximal oxygen uptake.

Thirty-three college women (mean age = 21.8 years) participated in a 5 d X wk-1, 12 week training program. Subjects were randomly assigned to 3 groups, above lactate threshold (greater than LT) (N = 11; trained at 69 watts above the workload associated with LT), = LT (N = 12; trained at the work load associated with LT) and control (C) (N = 10). Subjects were assessed for VO2max, VO2LT, VO2LT/VO2max, before and after training, using a discontinuous 3 min incremental (starting at 0 watts increasing 34 watts each work load) protocol on a cycle ergometer (Monark). Respiratory gas exchange measures were determined using standard open circuit spirometry while LT was determined from blood samples taken immediately following each work load from an indwelling venous catheter located in the back of a heated hand. Body composition parameters were determined before and after training via hydrostatic weighing. Training work loads were equated so that each subject expended approximately 1465 kJ per training session (Monark cycle ergometer) regardless of training intensity. Pretraining, no significant differences existed between groups for any variable. Post training the greater than LT group had significantly higher VO2max (13%), VO2LT (47%) and VO2LT/VO2max (33%) values as compared to C (p less than .05). Within group comparisons revealed that none of the groups significantly changed VO2max as a result of training, only the greater than LT group showed a significant increase in VO2LT (48%) (p less than .05), while both the = LT and greater than LT group showed significant increases in VO2LT/VO2max (= LT 16%, greater than LT 42% (p less than .05)).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗