• BMB Reports
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• v.39 no.4
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• pp.426-431
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• 2006

Embryonic stem cells (ESCs), representing a population of undifferentiated pluripotent cells with both self-renewal and multilineage differentiation characteristics, are capable of spontaneous differentiation into cardiomyocytes. The present study sought to define the kinetic characterization of lactate dehydrogenase (LDH) and creatine kinase (CK) of ESC- and neonatal-derived cardiomyocytes. Spontaneously differentiated cardiomyocytes from embryoid bodies (EBs) derived from mouse ESC line (Royan B1) and neonatal cardiomyocytes were dispersed in a buffer solution. Enzymes were extracted by sonication and centrifugation for kinetic evaluation of LDH and CK with spectrophotometric methods. While a comparison between the kinetic properties of the LDH and CK of both groups revealed not only different Michaelis constants and optimum temperatures for LDH but also different Michaelis constants and optimum pH for CK, the pH profile of LDH and optimum temperature of CK were similar. In defining some kinetic properties of cardiac metabolic enzymes of ESC-derived cardiomyocytes, our results are expected to further facilitate the use of ESCs as an experimental model.

• Journal of Life Science
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• v.21 no.11
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• pp.1565-1572
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• 2011

Eye-specific lactate dehydrogenase (EC 1.1.1.27, LDH) $C_4$ isozyme in the eyes of greenlings (Hexagrammos otakii) was successfully purified by affinity chromatography and continuous-elution electrophoresis. The molecular weight of the purified eye-specific LDH $C_4$ isozyme was 154.8 kDa, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Optimal pH for enzymatic reaction of the eye-specific LDH $C_4$ isozyme was pH 8.5. $K^{PYR}_m$ value of the purified eye-specific LDH $C_4$ isozyme was $1.88{\times}10^{-5}$ M using pyruvate as a substrate. These results indicate that we must consider pH when measuring eye-specific LDH $C_4$ isozyme activity. The eye-specific LDH $C_4$ isozyme had a higher binding affinity for the substrate as a pyruvate than LDH A4 isozyme. Antibodies produced against the purified eye-specific LDH $C_4$ isozyme may be used in the diagnosis of several human diseases and in comparative physiological studies of fishes.

• Journal of Life Science
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• v.31 no.12
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• pp.1066-1071
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• 2021

The aim of this study was to examine the metabolic adjustment of lactate dehydrogenase (EC 1.1.1.27, LDH) isozymes to a change in dissolved oxygen (DO) in bluegill (Lepomis macrochirus). After bluegills were adapted to a constant environment in an aquarium, the DO was changed to investigate the activity of LDH isozyme and the relative ratio of subunits A, B, and C for each tissue. When the DO was decreased from 18 ppm to 6 ppm, LDH in skeletal muscle, heart, and brain tissues recovered to the level of control activity within 12, 12, and 6 hr, respectively. LDH activity changed in accordance with a change in DO. The compensation was performed rapidly and is thought to be an important function of LDH in enabling bluegills to adapt to their environment. In bluegill heart, eye, and brain tissues, the relative ratio of subunit A increased and showed a tendency to recover similarly to the subunit ratio of control groups up to 12 hr. It is thought that the anaerobic metabolism using subunit A was increased in the initial stage when DO was changed. In addition, the results revealed that subunit C was more similar to subunit A than subunit B. In bluegills, subunits A and C of LDH seem to be evolutionarily similar. LDH isozymes, mainly containing subunits A and C, are likely responsible for the function of pyruvate reductase, which plays a role in making the bluegill adapt to a hypoxic environment through anaerobic metabolism.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1411-1416
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• 2004

The objective of this work was to isolate a microorganism, able to produce high lactate dehydrogenase (LDH) activity, for use as a microbial feed additive. The LDH is an important enzyme for lactate conversion in the rumen, thereby possibly overcoming lactic acidosis owing to sudden increases of cereal in the diets of ruminants. In the present study, various bacterial strains were screened from a variety of environments. Among the isolated microorganisms, strain FFy 111-1 isolated from a Korean traditional fermented vegetable food called Kimchi showed the highest enzyme activity, along with retaining strong enzyme activity even in rumen fluid in vitro. Based on morphological and biochemical characteristics as well as compositions of cellular fatty acids plus API analyses, this strain was identified as Lactobacillus sp. The optimum temperature and pH for growth were found to be 30$^{\circ}C$ and pH 6.5, respectively. A maximum cell growth of 2.2 at $A_{650}$ together with LDH activity of 2.08 U per mL was achieved after 24 h of incubation. Initial characterization of FFy 111-1 suggested that it could be a potential candidate for use as a direct-fed microbial in the ruminant animals.

• The Korean Journal of Mycology
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• v.23 no.1 s.72
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• pp.86-91
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• 1995

Isoenzymatic analysis related with cadmium adaptation and detoxifying mechanism were carried out upon Rhizopus oryzae. When cadmium was added into R. oryzae culture, activities of malate dehydrogenase (MDH) and glucose phosphate isomerase (GPI) related with carbohydrate metabolizing pathways were stimulated. Novel isoenzyme CAT-2 related with removing intracellular toxic peroxides, was induced lately and derepressed very highly. On the other hand, lactate-catabolizing enzymes such as lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH) were repressed. These results strongly suggest that, under cadmium stress, much of derepression of enzymes relating with central metabolism such as TCA cycle that produces high yield of energy and relating with removal of toxic peroxides should be necessary.

• Journal of Life Science
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• v.14 no.4
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• pp.708-715
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• 2004

The lactate dehydrogenase (EC 1.1.1.27, LDH) in liver of Lempetra japonica was purified in buffer of affinity chromatography. The liver-specific $C_4$ isozyme of Gadus macrocephalus was purified by heat treatment, affinity chromatography, and DEAE-Sephacel chromatography. The liver-specific $C_4$ isozyme was eluted in a buffer containing NAD+ and was coeluted with $B_4$isozyme in plain buffer of affinity chromagraphy. Liver-specific $C_4$ isozyme in G. macrocephalus was the most thermostable, and$B_4$isozyme was more stable than $A_4$. The LDH in the fraction of pH 7.45 purified from the liver of L. iaponica by chromatofocusing was more inhibited by pyruvate than purified LDH. The optimum pH of the LDH isozyme in the liver of L. japonica was 7.5 and that of liver-specific$C_4$ isozyme was 8.5. The LDH in liver of L. japonica made complexes more with antibody against Coreoperca herzi$A_4$ and liver-specific $C_4$ than with that against eye-specific $C_4$. Therefore, the structure of the LDH in liver of L. japonica might be similarly evolved to that of subunit A and liver-specific $C_4$ isozyme in liver tissue of G. macrocephalus. The evolution rate of subunit C is faster than that of subunit A. LDH in liver of L. japonica has not one isozyme but isozymes and it was also found out to have not only subunit A and B but also subunit C.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.167-171
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• 1999

This study was designed to develop biomarkers of coastal pollution using biochemical indices of flounder (Paralichthys olivaceus) by changes in lactate dehydrogenase (LDH) activity in the serum and cholinesterase activities in brain membranes. For this purpose acetylcholiesterase (AChE) activity, butyrylcholinesterase (BChE) activity, LDH/AChE ratio and LDH/BChE ratio of cultured flounders at 5 different sites on the southern coast of Korea were compared to those of wild flounders caught in the Pohang, eastern coast of Korea as a control group. Relatively high LDH activities were measured in the serum of flounders cultured on the southern coast of Korea (0.101-0.145 unit) than those in the Pohang control group (0.093 unit). AChE activities were significantly low $(about\;10-20\%)$ in brain membranes of cultured flounders compared to those in the Pohang control group. The ratios of LDH/AChE and LDH/BChE were consistently higher $(136-178\%,\; 155-214\%)$ in cultured flounders than those of Pohang control group. Thus, we propose that the ratios of LDH/AChE and LDH/BChE in flounders could be applicable for the diagnosis of marine pollution.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.263-270
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• 1999

In order to identify the morphological changes of tissues in mouse after irradiation. We have observed the redistribution of LDH isozymes and the morphological changes of skeletal muscle, heart, kidney, liver and testis in mouse according to variation amount with the time after the 1 Gray and 3 Gray irradiation each. As a result of H-E (hematoxylin-eosin) stain, the apoptotic bodies were more easily observed in the liver than the other tissues and the quantity of the apoptotic bodies was proportionated to radiation amount. The number of apoptotic bodies was shown the highest at 1 day in most tissues and at 7 day in testis after irradiation. TUNEL (terminal deoxyribonucleodtidyl transferase-mediated dUTP-digoxigenin nick end labeling) staining was shown the same results as H-E staining. After the irradiation, the protein content was reduced in tissues except kidney. And protein content was reduced in all tissues at the initial period of 2 hours after 3 Gy irradiation. But it increased at 7 days after irradiation. LDH (EC 1.1.1.27, lactate dehydrogenase) activity was increased mostly in tissues at the early stage after 1 Gy irradiation. The maximum activity was detected earlier stage after 1 Gy irradiation than 3 Gy irradiation. The activity of LDH $A_4$ isozyme was decreased in the skeletal muscle, heart, kidney, and testis. The activity of $B_4$ and $A_2$$B_2$ sozyme was increased in the skeletal muscle and heart, and the activity of heterotetramer isozyme was increased in kidney The activity of $A_4$ isozyme in liver was detected high level and the activity of isozyme including subunit C elevated in testis. Therefore, LDH isozyme seems to play a role of lactate oxidase in most tissues except liver after irradiation. These data support that LDH isozyme is predomintly involved in the aerobic metabolism.

• The Korean Journal of Zoology
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• v.15 no.3
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• pp.105-110
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• 1972

A cellulosse acetate electrophoretic survey of Korean Anura has revealed the presence of diverse lactate and malate dehydrogenase (LDH and MDH) isozymes. The pattern of LDH and MDH isozymes in the tissues of the central nervous system of the six species of Anura examined are species specific and differ from those of mammals and birds. Both Rana nigromaculata nigromaculata and Rana nigromaculata coreana have two molecular forms of LDH and MDH, respectively, with almost the same pattern. Whole brain homogenate of Rana temporaria shows also a maximum of only two LDH isozymes. Both Bufo bufo asiaticus and Bombina orientalis have five molecular forms of LDH with an entirely different spacing on the zymograms, whereas Rana rugosa has three. Two molecular forms of MDH are present in all animals examined and one band is shown in olfactory lobe and mixture of cerebellum and medulla oblongata of Rana nigromaculata nigromaculata.

• Development and Reproduction
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• v.16 no.3
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• pp.219-226
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• 2012

It is suggested that carbohydrate metabolites may involve in the development of morula to blastocyst but many of the mechanisms are not unmasked. Two-cell stage embryos were collected and examined the effects of lactate on the development of blastocyst in vitro. The expression profiles of lactate dehydrognase (Ldh) genes and aquaporin (Aqp) genes were analyzed with RT-PCR. The successful development from morula to blastocyst was dependent on lactate concentrations. The expression profiles of Ldh genes were changed by the lactate concentration. Ldha was expressed in morula stage at 10 mM lactate, and in blastocyst stage at lactate free condition. Ldhb was expressed in morula stage at 10 mM and 20 mM lactate, and in blastocyst stage at 10 mM lactate. Aqp genes were also showed different expression patterns by the lactate concentrations. Aqp3 was expressed in hatching embryo at 120 hr post hCG administration (hph) which was cultured in BWW medium and lactate free condition. Aqp7 was expressed in hatching embryos at 120 hph which was cultured at 10 mM lactate condition. Also Aqp8 was expressed in hatching embryo at BWW and 20 mM lactate condition. Aqp9 was expressed in morula at BWW and 10 mM lactate condition, and in blastocyst at BWW. Based on these results, it is suggested that concentration of lactate in the medium and the level of lactate synthesis in embryo is critical factor for blastocoels formation. In addition it is suggested that LDH may involve the AQPs expression in embryos.