Lactate Dehydrogenase Isoenzymes Research Articles

Serum bta-miRNA-375 as a potential biomarker for the early diagnosis of enzootic bovine leukosis.

To identify a biomarker for the early diagnosis of enzootic bovine leukosis (EBL) caused by bovine leukemia virus (BLV), we investigated the expression of a microRNA, bta-miR-375, in cattle serum. Using quantitative reverse-transcriptase PCR analysis, we measured bta-miR-375 levels in 27 samples from cattle with EBL (EBL cattle), 45 samples from animals infected with BLV but showing no clinical signs (NS cattle), and 30 samples from cattle uninfected with BLV (BLV negative cattle). In this study, we also compared the kinetics of bta-miR-375 with those of the conventional biomarkers of proviral load (PVL), lactate dehydrogenase (LDH), and thymidine kinase (TK) from the no-clinical-sign phase until EBL onset in three BLV-infected Japanese black (JB) cattle. Bta-miR-375 expression was higher in NS cattle than in BLV negative cattle (P < 0.05) and greater in EBL cattle than in BLV negative and NS cattle (P < 0.0001 for both comparisons). Receiver operating characteristic curves demonstrated that bta-miR-375 levels distinguished EBL cattle from NS cattle with high sensitivity and specificity. In NS cattle, bta-miR-375 expression was increased as early as at 2 months before EBL onset-earlier than the expression of PVL, TK, or LDH isoenzymes 2 and 3. These results suggest that serum miR-375 is a promising biomarker for the early diagnosis of EBL.

Transcriptional regulation of lactate dehydrogenase activity in rat kidney cells in diabetic nephropathy

Aim. To study the features of transcriptional regulation of the activity and isoenzyme composition of lactate dehydrogenase in the kidneys of Rattus norvegicus L. in diabetic nephropathy.Materials and methods. The study included 20 male laboratory rats (Rattus norvegicus L.) divided into two equal groups: “Norm” – intact rats injected with 0.9% NaCl intraperitoneally and “Diabetes” – animals with alloxaninduced diabetes (DM1 model). The activity, subcellular localization, and mobility of lactate dehydrogenase (LDH, EC 1.1.1.27) isoenzymes were studied using spectrophotometry and electrophoresis. LDHA and LDHB gene transcripts were analyzed by the polymerase chain reaction.Results. Analysis of the LDH activity showed that this parameter increased by more than 6 times in the animals with diabetic nephropathy compared to the control group. Moreover, the increase in the rate of the LDH activity was a consequence of the enzyme activation in all the studied compartments of the cell and is consistent with the parameter in the homogenate. The increase in the LDH activity in diabetic nephropathy may result from redistribution of the activity rate between the available isoforms and may be associated with an increase in the transcription rate of genes encoding subunits A and B of this enzyme.Conclusion. The increase in the LDH activity is likely associated with the activation of renal gluconeogenesis, the main substrate for which is lactic acid reabsorbed in the renal glomeruli. The revealed increase in the LDH activity in the kidneys of rats with diabetic nephropathy may be associated with adaptation of their metabolism to the pathological state.

Study of Association of Chromosomal Region 1Q21-23 with Rheumatoid Arthritis and Their Correlation with Severity of Disease.

The understanding of the pathophysiology of rheumatoid arthritis (RA) has taken a major step forward with the research of new illness-related genes and further deciphering the involved molecular. Gene variants like human leukocyte antigen (HLA)-DRB1 and PTPN22 1858T act as individual risk factors for RA. It also serves as a risk factor for the rate of progression of joint destruction and clinical manifestations in autoimmune diseases like RA. The focus of this study is to find out the association of chromosomal region 1q21-23 with RA and its connection with disease severity using the disease activity score (DAS) and distribution frequency of the prevalent alleles of such genes in an already recruited group of patients/controls of India, specifically Northwest Rajasthan. This was a case-control study wherein every patient of RA aged 16 years and above diagnosed with RA as per the 2010 American College of Rheumatology (ACR) and the European League against Rheumatism (EULAR) revised criteria for RA in Outpatient Department (OPD) and Inpatient Department (IPD) patients were included. Blood samples of the study population were drawn at Sardar Patel Medical College (SPMC), Bikaner (rheumatology OPD), along with the cooperation of Birla Institute of Technology and Science (BITS), Hyderabad (Department of Biological Sciences) from July 2009 to January 2012. A total of 100 controls (without any previous history of disease) and 135 cases were selected considering inclusion and exclusion criteria. Clinical data along with laboratory parameters like complete blood count, serum electrolytes (sodium, potassium, calcium, and chlorine ions), blood sugar, blood urea with serum creatinine, lactate dehydrogenase (LDH) isoenzymes assay, serum glutamic-oxaloacetic transaminase (SGOT)/serum glutamic pyruvic transaminase (SGPT) ratio, serum γ-glutamyl transferase (GGT) level, serum amylase, arterial blood gas (ABG), total serum proteins were evaluated and recorded from the patients. Our study showed control group has a mean age of 45.11 + 4.12 years. The case and control groups did not have significant differences in any of the clinical variables. 59% of cases show joint deformity. Allelic frequencies of the D1S498 polymorphism in cases were found significant in sizes 198, 204, 208, and 210, while it was found insignificant in sizes 192, 196, 200, 202, and 206. No correlation was found in allelic frequencies of the D1S318 polymorphism in cases and controls. Bigger cohort studies will allow better genomic elucidation of clinically defined intermediate phenotypes evaluated in RA patients by virtue of the autoimmune origin of the disease and its diverse symptoms in patients. Genetic-molecular studies can be a milestone for adopting effective personalized treatment for such progressively debilitating diseases. How to cite this article: Gauri LA, Meena MK, Singh U, et al. Study of Association of Chromosomal Region 1Q21-23 with Rheumatoid Arthritis and Their Correlation with Severity of Disease. J Assoc Physicians India 2023;71(9):28-32.

Acclimation to warm temperatures modulates lactate and malate dehydrogenase isozymes in juvenile Horabagrus brachysoma (Günther)

Differential expression of isozymes enables fish to tolerate temperature fluctuations in their environment. The present study explores the modulation of lactate dehydrogenase (LDH) and cytoplasmic malate dehydrogenase (sMDH) isozyme expression in the heart, muscle, brain, liver, gill, and kidney of juvenile Horabagrus brachysoma after 30 days of acclimation at 26, 31, 33, and 36°C. LDH and sMDH zymography were performed using native polyacrylamide gel electrophoresis. The zymography revealed five distinct bands of LDH isoenzymes (labelled from cathode to anode as LDH-A4, LDH-A3B1, LDH-A2B2, LDH-A1B3, and LDH-B4) and three distinct bands of sMDH isoenzymes (labelled from cathode to anode as sMDH-A2, sMDH-AB, and sMDH-B2), with considerable variation in their expression in the tissues. Acclimation to the test temperatures did not influence the expression patterns of LDH or sMDH isozymes. Densitometric analysis of individual isozyme bands revealed a reduction in the densities of bands containing the LDH-B and sMDH-B molecules, while the densities of bands containing the LDH-A and sMDH-A molecules increased in the gills and muscle, indicating the role of these organs in adaptive responses to thermal acclimation. However, the total densities of the LDH and sMDH isozymes increased with higher acclimation temperatures, indicating that adaptation to increased temperatures in H. brachysoma is primarily characterised by quantitative changes in isozyme expression.

Serum lactate dehydrogenase and its isoenzymes as predictors of clinical outcomes in acute exacerbation of chronic obstructive pulmonary disease: a retrospective analysis of a hospitalized cohort.

We aimed to test the relationship between serum lactate dehydrogenase (LDH) and its isoenzymes and treatment outcomes during hospitalization for acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Thirty-eight AECOPD patients were recruited from a tertiary hospital from December 2017 to June 2018. Serum LDH and LDH isoenzymes were measured on venous blood collected at admission. Treatment outcomes included duration of hospital stay, initiation of mechanical or non-invasive ventilation (NIV), initiation of antipseudomonal antibiotics, change in empirical antibiotic treatment, need for intravenous corticosteroids or methylxanthines, and percentage of change in C-reactive protein from admission to the third day. Multivariate linear and binary logistic regression analyses were used to test the study's objectives. We found that, after adjusting for age, gender, comorbidities, COPD severity, level of hypoxemia, and inflammation markers, each 10 U/L increase in serum LDH was associated with prolongation of the hospital stay by 0.25 (0.03, 0.46) days, 42% higher odds [odds ratio (OR) 1.42 (1.00, 2.03)] for need of NIV, and 25% higher odds [OR 1.25 (1.04, 1.49)] for initiation of antipseudomonal treatment. LDH1 and LDH2 were the LDH isoenzymes that mainly drove these relationships. LDH release in the context of an AECOPD could originate from lung, muscle, or heart tissue damage due to airway inflammation, respiratory muscle recruitment, and myocardial stress. Myocardial injury and aerobic adaptation in respiratory muscles may explain the predominance of LDH1 and LDH2 isoenzymes in these associations.

The lactate dehydrogenase (LDH) isoenzyme spectrum enables optimally controlling T cell glycolysis and differentiation.

Isoenzyme divergence is a prevalent mechanism governing tissue-specific and developmental stage-specific metabolism in mammals. The lactate dehydrogenase (LDH) isoenzyme spectrum reflects the tissue-specific metabolic status. We found that three tetrameric isoenzymes composed of LDHA and LDHB (LDH-3/4/5) comprise the LDH spectrum in T cells. Genetically deleting LDHA or LDHB altered the isoenzyme spectrum by removing all heterotetramers and leaving T cells with LDH-1 (the homotetramer of LDHB) or LDH-5 (the homotetramer of LDHA), respectively. Accordingly, deleting LDHA suppressed glycolysis, cell proliferation, and differentiation. Unexpectedly, deleting LDHB enhanced glycolysis but suppressed T cell differentiation, indicating that an optimal zone of glycolytic activity is required to maintain cell fitness. Mechanistically, the LDH isoenzyme spectrum imposed by LDHA and LDHB is necessary to optimize glycolysis to maintain a balanced nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide hydrogen pool. Our results suggest that the LDH isoenzyme spectrum enables "Goldilocks levels" of glycolytic and redox activity to control T cell differentiation.

To evaluate the role of lactate dehydrogenase as biomarker in the progression of potentially malignant disorders in smokers and gutkha chewers.

To evaluate the role of lactate dehydrogenase (LDH) as a biomarker in the progression of potentially malignant disorders in smokers and gutkha chewers. The total of 70 individuals having the habit of chewing gutkha and smoking were selected for the study and divided into four groups. Group 1: 20 individuals having the habit of smoking, Group 2: 20 individuals having the habit of chewing gutkha, Group 3: 20 individuals having the habit of smoking and gutkha chewing, and Group 4: 10 healthy individuals. In the present study showed that unstimulated whole saliva from group 1, group 2, and group 3 individuals, there was a significant decrease in isoenzymes LDH-1 and LDH-2 and there was no effect on LDH-3 isoenzyme. In the present study, there is a significant increase in salivary isoenzyme LDH-4. The result indicated that there is an effect of carcinogen (tobacco)-enhanced activity on salivary LDH. The present study showed 70 volunteers reported a statistical significant correlation among the groups. The individuals with habit of smoking and gutkha chewing showed P value <.001 with a significant increase in the isoenzyme LDH-4. A significant increase in the buccal micronuclei of exfoliated cells in the oral mucosal cells of smokers and gutkha chewers. This shows a positive relationship between LDH isoenzymes and the individuals with the smoking and chewing of tobacco. There was a significant correlation between the levels of salivary LDH isoenzymes and cytomorphometric analysis of oral epithelium in smokers and gutkha chewers.

Agarose gel electrophoresis pattern of serum creatine kinase and lactate dehydrogenase isoenzymes in zoo-managed Asian elephants (Elephas maximus).

Serum levels of creatine kinase (CK) and lactate dehydrogenase (LDH) isoenzymes were evaluated in nine zoo-managed Asian elephants (Elephas maximus) using a commercial agarose gel electrophoresis (AGE) kit. CK was separated into two major fractions, CK-BB and CK-MM, along with a small fraction of macroenzyme-CK type 2 (mCK2); CK-MM was the largest fraction. LDH was separated into five fractions (LDH1-5); LDH3 was the largest fraction. Age was negatively and positively correlated with the percentages of CK-BB and CK-MM, respectively, and negatively correlated with CK-BB and mCK2 activities. These results indicate that an AGE kit can be used to evaluate CK and LDH isoenzymes. Routine isoenzyme testing may enable early detection of disease and physiological changes.

Usefulness of determining some markers of myocardial damage in sports horses subjected to physical exertion

The aim of the study was to evaluate the usefulness of determining markers of myocardial damage, such as: aspartate aminotransferase, total creatine kinase, cardiac creatine kinase isoenzyme, total lactate dehydrogenase, cardiac lactate dehydrogenase isoenzyme and peripheral blood lactic acid in sport horses subjected to physical exertion. The research was carried out on 50 horses of three breeds: Ukrainian Riding, Hanoverian and Westphalian, aged 4-16 years. In all horses, the activity of: aspartate aminotransferase, total creatine kinase, cardiac creatine kinase isoenzyme, total lactate dehydrogenase, cardiac isoenzyme lactate dehydrogenase and lactic acid concentration were marked before and after exercise. It was found that after physical exercise in the tested horses, there was an increase in markers of myocardial damage. On the basis of the conducted research, it was demonstrated that the highest increase concerned the concentration of lactic acid and the activity of the cardiac isoenzyme of creatine kinase. The conducted studies additionally indicate that the evaluation markers of myocardial damage in horses may be useful as a screening test in detecting cardiac muscle disorders associated with excessive exercise. However, it should be emphasized that it must be considered together with the results of a clinical examination and additional tests such as cardiac ultrasound and electrocardiography.

Cancer-testis antigen lactate dehydrogenase C4 as a novel biomarker of male infertility and cancer.

A unique lactate dehydrogenase (LDH) isoenzyme designated as lactate dehydrogenase C4 (LDH-C4) is found in mammalian mature testis and spermatozoa. Thus far, LDH-C4 has been well studied with regard to its gene and amino acid sequences, structure, biological properties, and peptide synthesis. Accumulating evidence has shown that LDH-C4 is closely related to spermatic energy metabolism and plays a critical role in sperm motility, capacitation, and fertilization. Defects in the catalytic activity of LDH-C4 are key to pathophysiological abnormalities underlying infertility. LDH-C4 was originally thought to be present only in mature testis and spermatozoa; however, recent studies have implicated LDH-C4 as a cancer-testis antigen (CTA), owing to its aberrant transcription in a broad spectrum of human neoplasms. This review highlights the recent findings on LDH-C4 with particular emphasis on its role in male infertility and tumors.

A Comparative Study of Biochemical Markers in the Early Diagnosis of Acute Myocardial Infarction (AMI)

Background: One of the most effective instances of readily detected biomarkers diagnosing a very big health concern is the measuring of proteins in blood to represent heart damage. The idea of utilizing a blood test to reflect organ or cell harm necessitates a chemical that is plentiful in the target cell, can reach blood, has a suitable half-life in blood, and is preferably in a particular form that only reflects the target cell in tissue. Because contraction is the primary function of the myocyte, proteins involved in contraction or the energy required to sustain it should be suitable potential indicators. The work on diagnostic tests for myofibrillar proteins begins in 1978. Different key pieces of evidence fueled in the research. In Ist-year outcomes were identical in chest pain patients whose acute myocardial infarction (AMI) was ruled out by electrocardiography and cardiac enzymes, demonstrating that the existing diagnostic tools were not beneficial for risk prediction and treatment recommendations. Second, CK and lactate dehydrogenase isoenzymes were brought into clinical practice and demonstrated to have higher specificity and sensitivity than traditional tests. All of the biomarkers used to diagnose cardiac injury are involved in contraction or energy metabolism, but the markers evolved via trial and error, beginning with transaminases in the 1950s and ending with troponins in the 1990s. This background is discussed, along with observations on my experiences establishing CK-MB and Troponin I assays. Methods: 140 individuals with AMI are included who are diagnosed using WHO criteria. A cross-sectional study with purposive sampling technique is conducted in wazirabad institute of Cardiology. This research is last around 6 months. Before the examinations, blood samples are obtained from patients by vein puncture using syringes and preserved in clot tubes. The research includes patients experiencing chest pressure, tightness, or discomfort, shortness of breath, and irregular cardiac rhythms on ECG. Patients having a normal ECG are not included in the study. Different equipments are utilized to assess appropriate heart function and to obtain serum for the identification of various cardiac biomarkers. Result: The sensitivities of all biochemical markers change depending on the time of infarction, as previously demonstrated and expected from a patho-physiologic standpoint, the blood sample of all the patients was collected and used for further investigation in the Lab. In the current study, 140 patients are enrolled, and all of the patients who had a single episode of AMI had their ECGs taken. All of the patients' ECGs are abnormal. In compared to other Bio-Cardiac Markers, the Troponin –I has a higher ratio of patients, according to the present findings. When a person undergoes AMI, the first protein that is released is troponin-I. When these tests are conducted over a period of time, they provide us with a quick assessment of the severity of AMI. As a result of the current findings, patients have a higher level of Trop-I in their blood when they experience their first episode of AMI. In this situation, the patient should go to the nearest health care center's emergency room as quickly as feasible. Conclusion: The traditional enzymatic assays of creatine kinase (CK), CK-MB (activity), and lactate dehydrogenase are rapidly being replaced by mass measurements of myoglobin, CKMB, and troponin T and troponin I (Tnl) 1 " to achieve high diagnostic sensitivity and specificity within a few hours from the onset of tissue necrosis; the ultimate goal is the early and appropriate management of patients' conditions. We compared the diagnostic sensitivity and specificity obtained by measuring various biochemical markers, some of which are widely used, and concluded that Troponin I is the first cardiac marker that releases simultaneously after the first episode of AMI when performed as single tests and in parallel and serial modes.

Expression Levels and Activity of Rat Liver Lactate Dehydrogenase Isoenzymes in Alloxan Diabetes

Expression Levels and Activity of Rat Liver Lactate Dehydrogenase Isoenzymes in Alloxan Diabetes

Quality care guidelines for uterine artery embolisation in women with symptomatic uterine fibroids in Australia and New Zealand: According to the AGREE-II checklist and endorsed by the Interventional Radiology Society of Australasia.

Quality care guidelines for uterine artery embolisation in women with symptomatic uterine fibroids in Australia and New Zealand: According to the AGREE-II checklist and endorsed by the Interventional Radiology Society of Australasia.

Diagnostic performance of lactate dehydrogenase (LDH) isoenzymes levels for the severity of COVID-19.

Lactate dehydrogenase (LDH) levels predict coronavirus disease 2019 (COVID-19) severity. We investigated LDH isoenzyme levels to identify the tissue responsible for serum LDH elevation in patients with COVID-19. Hospitalised COVID-19 patients with serum LDH levels exceeding the upper reference limit included. LDH isoenzymes were detected quantitatively on agarose gels. The radiological severity of lung involvement on computed tomography was scored as 0-5 for each lobe (total possible score, 0-25). Disease severity was determined using the World Health Organization (WHO) clinical progression scale. In total, 111 patients (mean age, 59.96 ± 16.14), including 43 females (38.7%), were enrolled. The serum levels of total LDH and all five LDH isoenzymes were significantly higher in the severe group. The levels of all LDH isoenzymes excluding LDH5 positively correlated with the WHO score. LDH3 levels correlated with chest computed tomography findings (r2 = 0.267, p = 0.005). On multivariate analysis, LDH3 was an independent risk factor for the deterioration of COVID-19. LDH3 appears to be an independent risk factor for deterioration in patients with COVID-19. LDH elevation in patients with COVID-19 predominantly resulted from lung, liver and muscle damage.

Diagnostic utility of measuring lactate dehydrogenase levels and its isoenzyme activities for the evaluation of malignancy in feline pleural effusion and ascitic fluid.

Lactate dehydrogenase (LDH) isoenzymes may be useful in the differential diagnosis of pleural effusion (PE) and ascitic fluid (AF) etiologies in cats since tissue damage induces their release, changing the pattern of their activity. This study aimed to determine the diagnostic utility of measuring LDH levels and isoenzyme activities in PE or AF in cats with malignancy. LDH levels and isoenzyme activities in the serum, PE, and AF were compared among cats in the malignant, infectious, and non-malignant, non-infectious groups. A receiver operating characteristic (ROC) analysis was performed to assess the accuracy in diagnosing feline malignancy. Significant differences in LDH level and LDH isoenzyme activities in the PE and AF were observed among the three groups. The combination of LDH level and LDH-1 activity in PE or AF had the highest area under the ROC (AUC) values for discriminating malignant effusion from non-malignant effusion. The AUC of the combination of LDH level and LDH-1 activity in PE or AF was 0.874. The sensitivity and specificity of using the combination of LDH level (cut-off: <2,269 U/l) and LDH-1 activity (cut-off: <4.8%) in PE or AF for predicting malignancy with the highest AUC value were 94.4% and 72.7%, respectively. Our results suggest that the combination of LDH level and LDH-1 activity in PE or AF is a potential factor for diagnosing malignancy. Considering that LDH isoenzymes can be measured inexpensively and easily, LDH tests can be readily accommodated in veterinary clinical practice.

Red Blood Cell Mechanical Fragility as a Potential Predictor of Long-Term Hemolysis from Ventricular Assist Devices

Introduction: Recent improvement in design and performance of Left Ventricular Assist Devices facilitate their use for destination therapy. The shear stresses in such devices can damage patients’ red blood cells (RBC), leading to increased hemolysis, which has been associated with pump thrombosis and patient mortality. Here we report an investigation assessing RBC mechanical fragility as a potential metric of blood damage and its potential utility in monitoring LVAD performance. Methods: Twenty subjects were recruited from the Center for Circulatory Support at the University of Michigan. Thirteen were implanted with the HeartWare HVAD (Medtronic, Inc.) and 7 with HeartMate 3® LVAD (HM3; Abbott Labs). Blood samples were obtained before surgery and at 1 hour, 24 hours, 1 week and 4 weeks after. Hemolysis biomarkers, total lactate dehydrogenase (LDH) and LDH isoenzymes, bilirubin, haptoglobin, and serum hemoglobin were determined through standard clinical tests. Mechanical fragility, as a metric of sub-hemolytic RBC damage, was determined using electromagnetically driven bead milling in a tube with a cylindrical bead, combined with non-invasive spectrophotometric analysis of induced hemolysis upon selected durations of the stress application. Certain variations of the stressing regime were employed for comparison. Results: RBC mechanical fragility, as assessed through some of the stress application regimes, was correlated with certain hemolysis metrics like bilirubin, LDH, and LDH1. Specifically, a subset of pre-surgery RBC mechanical fragility markers were strongly correlated with bilirubin levels measured 1 day, 1 week, and 1 month (though not immediately) after the surgery. While such correlation with unconjugated bilirubin declined in significance over time, the correlation to conjugated bilirubin reached significance at 1 month. Mechanical fragility values determined in albumin-supplemented medium at 1-day post-surgery, showed strong correlation to total LDH and LDH1 at 1-month post-surgery (p &lt; 0.01, R2 up to 0.45), with the correlation with LDH1 stronger than with total LDH. Conclusions: These data demonstrate the potential for some RBC mechanical fragility metrics as predictive prognostic biomarkers for hemolysis induced by implantable circulatory support systems. With appropriate tailoring of testing parameters to best suit the application, mechanical fragility assays could help facilitate the transition to greater utilization of ventricular assist devices.

Expression levels and activity of rat liver lactate dehydrogenase isoenzymes in alloxan diabetes

A significant decrease in the activity of lactate dehydrogenase (LDH, EC 1.1.1.27) in liver cells of rats with alloxan diabetes was found due to a decrease in the expression of the corresponding genes. The decrease in the activity of the enzyme under study in experimental type I diabetes was associated with inactivation of the cytoplasmic isoform of LDH. It was found that the level of ldha and ldhb gene transcripts in the liver of healthy rats was higher than in animals with alloxan diabetes. The ldha gene expression demonstrated almost 9-fold decrease, while a decrease in the ldhb gene expression was less pronounced (just 1.25-fold). Probably, the decrease in the rate of functioning of the enzyme under study is associated with a decrease in the intensity of glucose uptake by cells, which leads to inhibition of glycolysis and intensification of all stages of gluconeogenesis, particularly, reversed glycolysis reactions. Thus, the data obtained by us indicate an important role of LDH in the adaptive response of cellular metabolism in the development of type I diabetes mellitus.

Expression levels and activity of rat liver lactate dehydrogenase isoenzymes in alloxan diabetes

A significant decrease in the activity of lactate dehydrogenase (LDH, EC 1.1.1.27) in liver cells of rats with alloxan diabetes was found due to a decrease in the expression of the corresponding genes. The decrease in the activity of the enzyme under study in experimental type I diabetes was associated with inactivation of the cytoplasmic isoform of LDH. It was found that the level of ldha and ldhb gene transcripts in the liver of healthy rats was higher than in animals with alloxan diabetes. The ldha gene expression demonstrated almost 9-fold decrease, while a decrease in the ldhb gene expression was less pronounced (just 1.25-fold). Probably, the decrease in the rate of functioning of the enzyme under study is associated with a decrease in the intensity of glucose uptake by cells, which leads to inhibition of glycolysis and intensification of all stages of gluconeogenesis, particularly, reversed glycolysis reactions. Thus, the data obtained by us indicate an important role of LDH in the adaptive response of cellular metabolism in the development of type I diabetes mellitus.V pecheni krys s alloksanovym diabetom obnaruzheno znachitel'noe snizhenie aktivnosti laktatdegidrogenazy (LDG, KF 1.1.1.27), obuslovlennoe umen'sheniem ékspressii sootvetstvuiushchikh genov. Éto snizhenie aktivnosti LDG, po-vidimomu, sviazano s umen'sheniem urovnia tsitoplazmaticheskoĭ izoformy LDG. Vyiavleno, chto kontsentratsiia transkriptov genov ldha i ldhb v pecheni zdorovykh krys vyshe, chem u zhivotnykh s alloksanovym diabetom. Prichem ékspressiia gena ldha byla snizhena pochti v 9 raz, togda kak ékspressiia gena ldhb snizhalas' vsego lish' v 1,25 raza. Poluchennye nami dannye svidetel'stvuiut o vazhnoĭ roli LDG v adaptivnoĭ reaktsii kletochnogo metabolizma pri razvitii sakharnogo diabeta I tipa.

Sesamol Supplementation Mitigates Isoproterenol-Induced Cardiac Toxicity in Rats by Stabilizing Cardiac Mitochondrial and Lysosomal Enzymes

The current investigation was intended to evaluate the antimyocardial ischemic effects of sesamol on lactate dehydrogenase (LDH) isoenzymes, DNA damage, and mitochondrial and lysosomal enzyme activities in isoproterenol (ISO)-induced myocardial infarction (MI) in male albino Wistar strain rats. Rats that received ISO (85 mg/kg body weight (B.W) subcutaneously) for the first 2 consecutive days showed significant reduction in the activities of tricarboxylic acid (TCA) cycle enzymes (isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, malate dehydrogenase, and succinate dehydrogenase) and respiratory chain enzymes (cytochrome c oxidase and nicotinamide adenine dinucleotide hydrogen (NADH) dehydrogenase) in the heart mitochondria. The activities of the lysosomal enzymes (α-and β-glucosidases, α and β-galactosidases, β-glucuronidase and β-N-acetyl glucosaminidase and cathepsin-B and cathepsin-D) were increased significantly in the heart homogenate of ISO-induced MI rats. ISO injection also increased the % of tail DNA, tail length, and tail moment and decreased the % of head DNA. Pretreatment with sesamol (50 mg/kg B.W) every day for a period of 9 days prevented the above abnormalities induced by ISO. In conclusion, it can be inferred that administration of sesamol has a potent beneficial role against ISO-induced damage to the mitochondria, lysosomes, and DNA, thereby preventing MI.

Evaluation of Serum Levels of Lactate Dehydrogenase Isoenzymes in COVID- 19 Patients

Background: This study aimed to determine the serum levels of lactate dehydrogenase isoenzymes (LDH1, LDH2, LDH3, LDH4, and LDH5) and their contribution to the total lactate dehydrogenase enzyme elevation observed in COVID-19 patients. Design of study: This study was conducted in collaboration between Al-Nahrain University/College of Medicine/Chemistry and Biochemistry Department and Al- Yarmouk Teaching Hospital, Baghdad, Iraq. The study included 90 patients with confirmed COVID-19 infection: 45 with severe symptoms, and 45 with mild symptoms during the period from February 2021 to June 2021. The different LDH isoenzymes (LDH1, LDH2, LDH3, LDH4, and LDH5) were determined by enzyme-linked immunosorbent assay (ELISA) kits. Results: This study showed high correlation between total lactate dehydrogenase (LDH) enzyme and disease progression and severity in patients with COVID-19. The study also showed significantly higher levels of the lactate dehydrogenase isoenzymes (LDH1, LDH3, and LDH4) in patients with severe symptoms. Conclusion: This study suggests that elevation of serum lactate dehydrogenase (LDH) in patients with COVID-19 may be associated with the release of more than one of LDH isoenzymes into the bloodstream, therefore the use of total LDH as a specific biomarker for lung affectation in patients with COVID-19 is not specific, but the assay of all LDH isoenzymes could give a better understanding of the tissues most affected by the virus.