• Journal of Life Science
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• v.15 no.1 s.68
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• pp.100-105
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• 2005

The lactate dehydrogenase (EC 1.1.1.27, LDH) inhibitors were isolated from the LDH-free crude mitochondrial fraction of skeletal muscle in Syrian hamster (Mesocricetus auratus) and Korean native cattle (Bos taurus coreanae). The LDH inhibitor in skeletal muscle of M. auratus was successfully isolated by the treatment with 175 mM NaCl and ultrasonic. The LDH inhibitor in skeletal muscle of B. taurus coreanae was highly stable to heat and LDH fu isozyme was largely inhibited by the LDH inhibitor. The molecular weight of inhibitor was 22 kDa. Inhibitor played an important role in the binding of LDH with the mitochondria in tissues of skeletal muscle, kidney and liver except heart.

• International journal of advanced smart convergence
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• v.11 no.4
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• pp.260-265
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• 2022

This study aimed to determine whether lactate dehydrogenase (LDH) levels in coronavirus disease (COVID-19) patients in Korea were higher than those in patients without COVID-19, and the effect of sex and age on LDH levels. A retrospective, observational study was conducted to measure LDH levels in 247 and 225 female and male COVID-19 patients, respectively, who were admitted to the study hospital between April 1 and October 30, 2020. Serum LDH levels were measured using an automated analyzer. Results: LDH levels were elevated in both male and female patients with COVID-19. Among patients with COVID-19, LDH levels were higher in males than in females, and LDH levels were higher in patients with COVID-19 than in patients in the control group. In the analysis of differences in LDH levels by age, LDH levels in patients with COVID-19 increased statistically significantly with age in males and females (males: p=0.001, females: p=0.001). By examining the differences in LDH levels according to sex and age, this study contributed to the basic biochemical data available in Korea, particularly regarding patients with COVID-19. Further research may be needed to examine confounding variables.

• Journal of Life Science
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• v.26 no.2
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• pp.155-163
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• 2016

Metabolism of lactate dehydrogenase (EC 1.1.1.27, LDH) was studied to identify the function of LDH-C. Tissues of LDH liver-specific Ldh-C expressed Carassius auratus and eye-specific Ldh-C expressed Lepomis macrochirus after starvation were studied. LDH activity in liver tissue from C. auratus was increased after starvation. And LDH specific activity (units/mg) and LDH/CS were increased in tissues. It means the anaerobic metabolism was taking place in C. auratus after starvation. LDH B₄ isozyme was decreased in skeletal muscle and increased in heart tissue. LDH C₄ isozymes those showed in eye and brain tissues were identified as liver-specific C₄ isozymes and disappeared after starvation. And C hybrid in eye, A₄ isozyme in brain, and both C hybrid and C₄ isozyme in liver tissue were increased, respectively. In L. macrochirus, the level of variation of LDH activities was low but greatly increased especially in eye tissue and LDH A₄ and AC hybrid were increased in brain tissue. The LDH activities in tissues from C. auratus and L. macrochirus remained 30.30-18.64% and 25-18.75%, respectively, as a result of the inhibition by 10 mM of pyruvate. The Km^PYR values of LDH in C. auratus were increased. As a result, LDH liver-specific C₄ isozyme was expressed in liver, brain and eye tissues during starvation. It seems metabolism of lactate was predominant in brain tissue. After starvation, the liver-specific LDH-C was affected more than eye-specific LDH-C.

• The Korean Journal of Food And Nutrition
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• v.14 no.4
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• pp.355-359
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• 2001

The purpose of this study was to compare the level of blood glucose and lactate and also plasma LDH production of college women in relation to exercise. College female student which majored athletics (E, exercise group, n=43) were recruited and compared with college women (Control group, n=60). Anthropometric measurements, triceps skinfold thickness were measured of two groups. And body fat mass and waist and hip circumferences were measured and the concentrations of plasma glucose, lactic acid and lactic acid dehydrogenase (LDH) were also assayed. Average height and weight of E group were slightly higher than that of control group. but there is no difference in body mass index (BMI) and waist hip ratio (WHR) between two groups. The percentage of body fat and body fat mass(kg) in E group was slightly lower than that of control group. Plasma glucose and LDH levels of E group were higher than those of control group, and plasma lactic acid concentration was significantly increased.

• Biomedical Science Letters
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• v.27 no.3
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• pp.170-176
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• 2021

Thapsigargin (TG), a sarco/endoplasmic reticulum (ER) Ca²⁺-ATPase (SERCA) inhibitor, has been widely used as an agonist for platelet aggregation for decades. In this study, we investigated the effect of TG on the release of lactate dehydrogenase (LDH) for platelets and elucidated its mechanism. Platelet LDH release and platelet aggregation were increased by TG treatment; 1,000 nM of TG induced the complete lysis of platelets. Other agonists such as collagen (2.5 ㎍/mL), thrombin (0.1 U/mL), and ADP (10 mM) did not induce significant platelet LDH release despite platelet aggregation. Finally, we investigated the effects of pharmacological inhibitors on TG-induced platelet aggregation and LDH release. SP600125, a JNK inhibitor, and LY294002, a PI-3K inhibitor, inhibited TG-induced platelet LDH release but not platelet aggregation. Forskolin, an adenylyl cyclase activator, also inhibited LDH release without affecting platelet aggregation by TG. These results suggest that the TG-induced platelet aggregation was accompanied by LDH release but regulated by a different signaling pathway.

• Journal of Life Science
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• v.14 no.4
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• pp.702-707
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• 2004

In native-polyacrylamide gel electrophoresis of Pangasius polyuranodon, the lactate dehydrogenase (EC 1.1.1.27, LDH) $A_4$, $A_3$B, $A_2$$B_2$,$AB_3$ and $B_4$ isozymes were expressed in various tissues. The LDH $A_4$ and liver-specific $C_4$ isozymes were expressed in the tissues of Hypostomus Plecostomus. The bands of LDH in skeletal muscle, heart and eye tissues were not detected while one band was detected in kidney and liver, and four bands were detected in brain. The detected one band in liver was identified as alcohol dehydrogenase and an anodal band of skeletal muscle was identified as nothing dehydrogenase. The LDH in skeletal muscle, heart and eye might function as pyruvate reductase. The degree of inhibitions of LDH in skeletal muscle and heart of P. polyuranodon by 10 mM pyruvate were measured 57.6% and 73.8%, respectively. However, those of LDH in tissues of H. plecostomus were measured 52.7-61.8% so tissue specificity did not appear. Therefore, H. ple-costomus might be more acclimated to hypoxic environment by anaerobic metabolism of LDH iso-zymes than P. polyuranodon.

• Journal of Ginseng Research
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• v.9 no.1
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• pp.72-85
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• 1985

Attempts were made to see if feeding of ginseng ethanol extract could affect proper- ties of rat brain lactate dehydrogenase such as specific activity, heat stability, Km for substrate, inactivation by 3-bromopyruvate and trypsin, and immune response. The following results were obtained. Specific activity of LDH was observed to reach maximum in 5 month after birth and then decrease steadily. However, that of LDH from rat fed with ginseng ethanol extract was found in rat fed with ginseng ethanol extract. 3-bromopyruvate was shown to inactivate LDH-5 from old rat fed. Inactivation of LDH-5 by trypsin was remarkable in old rat fed. Km value for pyruvate in old rat fed was remarkably decreased. Cumulative results suggest that ginseng ethanol extract could affect conformational change of LDH responsible for altered properties through unknown mechanism.

• Tuberculosis and Respiratory Diseases
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• v.87 no.1
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• pp.91-99
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• 2024

Background: Tuberculous pleural effusion (TPE) and parapneumonic effusion (PPE) are often difficult to differentiate owing to the overlapping clinical features. Observational studies demonstrate that the ratio of lactate dehydrogenase to adenosine deaminase (LDH/ADA) is lower in TPE compared to PPE, but integrated analysis is warranted. Methods: We conducted a systematic review to evaluate the diagnostic accuracy of the LDH/ADA ratio in differentiating TPE and PPE. We explored the PubMed and Scopus databases for studies evaluating the LDH/ADA ratio in differentiating TPE and PPE. Results: From a yield of 110 studies, five were included for systematic review. The cutoff value for the LDH/ADA ratio in TPE ranged from <14.2 to <25. The studies demonstrated high heterogeneity, precluding meta-analysis. Quality Assessment of Diagnostic Accuracy Studies Tool 2 assessment revealed a high risk of bias in terms of patient selection and index test. Conclusion: LDH/ADA ratio is a potentially useful parameter to differentiate between TPE and PPE. Based on the limited data, we recommend an LDH/ADA ratio cutoff value of <15 in differentiating TPE and PPE. However, more rigorous studies are needed to further validate this recommendation.

• Journal of Life Science
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• v.28 no.1
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• pp.1-8
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• 2018

To confirm the function of lactate dehydrogenase (LDH) (EC 1.1.1.27, LDH), its metabolism was studied by activity, kinetics, and isozyme analysis in tissues of Ldh testis-specific C expressing mice (Mus musculus) maintained in a state of starvation for 48 hr and 96 hr. In skeletal muscle, liver, and eye tissues, LDH and LDH $A_4$ activity increased and anaerobic metabolism predominated. While LDH activity in the heart and kidney tissues decreased, LDH $B_4$ activity increased and aerobic metabolism predominated, producing pyruvic acid. In the testis tissue, LDH $C_4$ activity decreased. In the brain tissue, LDH activity increased, but the isozyme change was small and the amount of pyruvic acid decreased. $K{_m}^{PYR}$ increased in tissues other than kidney tissue, and the affinity for pyruvic acid decreased. Consequently, in Ldh-A and B-expressing tissues, the activities of isozymes with higher concentrations increased. However, in Ldh-A, B, and C-expressing tissue, $C_4$ decreased and the function of the tissue also decreased. In particular, LDH in brain tissue played a role as a pyruvate reductase. Therefore, this process might be the mechanism for producing energy in the state of starvation.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.3
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• pp.199-206
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• 2005

연구목적: 난포가 폐쇄되는 동안의 생화학적 변화를 규명하기 위하여 미성숙 돼지의 정상 및 폐쇄 난포 내 lactate dehydrogenase (LDH) 활성도 변화 및 동일 난포액 내 스테로이드호르몬의 농도변화를 알아보기 위하여 본 연구를 시행하였다. 재료 및 방법: 난포액 (FF), 과립세포 (GC), 협막세포 (TC) 내 LDH의 활성도를 측정하였으며, 난포액 내 progesterone ($P_4$), testosterone (T), estradiol ($E_2$)의 농도변화를 방사면역측정법으로 정량하였다. 결　과: 정상 및 폐쇄 난포에서 $P_4$의 농도변화를 보이지 않았다. 그러나 폐쇄 난포액 내 T의 농도($3.85{\pm}1.50ng/ml$)는 정상 난포 ($1.29{\pm}0.54ng/ml$)에 비해 현저히 높았으며 정상 난포 내 $E_2$의 농도 ($43.29{\pm}19.51ng/ml$) 는 폐쇄 난포 ($18.82{\pm}7.27ng/ml$)에 비해 현저히 높은 것으로 나타났다. 정상 난포액 내 $P_4$의 농도는 난포의 크기에 정의 상관관계 (r=0.75)를 보였다. 정상 난포 내 T:$P_4$의 비율 ($8.14{\pm}3.35$)은 폐쇄 난포 ($1.39{\pm}0.60$)에 비해 현저히 높았으며, 정상 TC ($433.63{\pm}102.40{\mu}U/{\mu}g$ DNA) 및 FF ($246.86{\pm}58.96{\mu}U/{\mu}l$) 내 LDH 활성도는 폐쇄 난포 (각각 $83.7{\pm}10.5$와 $38.71{\pm}9.00$)에 비해 현저히 높게 나타났다. 정상 난포의 GC 및 FF 내 LDH 활성도는 $E_2$의 농도와 부의 상관관계를 보였지만, 폐쇄 난포의 TC 내 LDH 활성도는 $P_4$, T, $E_2$의 농도에 대해 정의 상관관계를 나타내었다. 결　론: 본 실험의 결과, 미성숙 돼지 난포의 폐쇄는 TC 내 LDH 활성도 감소와 밀접한 관계를 갖는 것으로 사료된다.