Lactate Dehydrogenase Isoenzyme Activity Research Articles

Rapid loss of lactate dehydrogenase isoenzyme activity in serum by cold-induced formation of immunoglobulin G-lactate dehydrogenase complex.

Lactate dehydrogenase (LD; EC 1.1.1.27) activity in serum from a patient recovering from a myocardial infarction was extremely unstable when stored at 0 degree C. The activity of each LD isoenzyme except LD-1 decreased by at least 40% when serum was stored at 0 degree C for 4 h. The patient's erythrocyte LD activity had normal stability at lower temperatures, but LD from other sources, when added to the patient's serum, rapidly lost activity at 0 degree C. The patient's serum contained an immunoglobulin G that combined--at 0 degree C but not at 21 degrees C--primarily with LD isoenzymes containing one or more M subunits. Because this immunoglobulin-LD complex has no enzyme activity, we used 125I-labeled purified LD to study formation of the complex. NAD+ blocked the formation of immunoglobulin-LD complex but could not dissociate the complex and restore the LD activity.

Lactate dehydrogenase and creatine kinase isoenzyme levels in the tissues and serum of normal lambs

The normal activities of lactate dehydrogenase and creatine kinase isoenzymes in the tissues and serum of clinically normal five-and-a-half-month-old lambs are presented. The percentage distribution of the lactate dehydrogenase isoenzymes in serum, liver, heart, lung and skeletal muscle were in agreement with previous studies but the distribution in ovine abomasum, small intestine, large intestine and red blood cells has not been previously described. Up to five creatine kinase isoenzymes were detected in ovine tissues and four in serum. One creatine kinase isoenzyme present in serum and tissues was thought to represent a mitochondrial isoenzyme which is absent from the normal serum of other species. Estimations of both lactate dehydrogenase and creatine kinase isoenzymes allowed all the tissues examined to be distinguished and were therefore more likely to allow tissue-specific isoenzyme patterns to be detected in serum than the estimation of the isoenzymes of either enzyme alone.

Seasonal acclimatization in anuran amphibians: Changes in lactate dehydrogenase specific activities and isoenzyme patterns in several tissues from a naturally occurring population of Discoglossus pictus pictus (Otth.)

1. 1. The effect of seasonal acclimatization over lactate dehydrogenase (LDH) specific activities and isoenzyme patterns from sartorius muscle, liver, heart and brain was studied in Discoglossus pictus pictus (Otth.). 2. 2. When measured at 30°C, LDH specific activity in muscle, heart and brain is maximal during autumn and minimal during spring. In liver there is only a drop in spring. 3. 3. There is an increase in H-type LDH isoenzyme activities during summer in liver, a decrease in these during winter and summer in heart, and a continuous decrease in M-type activities from autumn to summer in brain. 4. 4. The kinetic effect of environmental temperature over LDH catalytic activities and the data from a previous cold acclimation study are discussed. 5. 5. The variations in behavioural activity (and their metabolic consequences) and the existence of a circannual rhythm in D. pictus metabolism are suggested as responsible for the enzymatic changes.

Serum total and isoenzyme lactate dehydrogenase activity in American Burkitt's lymphoma patients.

Serum total lactate dehydrogenase (LDH) and LDH isoenzyme activities were studied in 45 American patients with a tissue diagnosis of Burkitt's lymphoma. Serum total LDH activity correlated with tumor burden as determined by clinical staging at presentation or clinical stage of the disease process ("disease status"). Tumor lysis by chemotherapy considerably increased the serum total LDH activity. For the LDH isoenzyme pattern, the largest relative increases were found with LDH3 and LDH4, whereas the highest isoenzyme activities occurred with LDH2 and LDH3. Thus, the total and isoenzyme LDH activities are helpful to evaluate the tumor burden and prognosis in patients with Burkitt's lymphoma.

Comparison of three serum α-hydroxybutyrate dehydrogenase procedures for lactate dehydrogenase isoenzyme discrimination

Three recently proposed methods for the assay of α-hydroxybutyrate (2-oxobutyrate) dehydrogenase (HBD) activity in serum were assessed to determine which one would give the most useful discrimination between the lactate dehydrogenase (LD) isoenzymes. The 2-oxobutyrate concentration and temperature for these procedures were 3.3 mmol/l at 30°C, 12 mmol/l at 30°C and 15 mmol/l at 37°C. LD isoenzyme activity values obtained by thin-layer agarose electrophoresis were compared with HBD activity results by linear regression analysis. The best, statistically significant, correlation of LD-1 with HBD activities was obtained with 3.3 mmol/l at 30°C (regression coefficient, 0.92; correlation coefficient, 0.98).

The diagnosis of myocardial infarction using cardiac-specific isoenzyme profiles

Creatine kinase (CK) and lactate dehydrogenase (LD) isoenzyme activities were measured in 100 patients with suspected acute myocardial infarction (AMI). The method employed was electrophoresis on thin agarose films using the Corning-ACl apparatus and reagents. The usefulness of this procedure as an aid to diagnosis and management was assessed. Specimens were collected at critical times on the enzyme release curve, the first on admission, then at intervals of 6-13 and 24-37 h. A comparison was made using significant elevations in total CK and α-Hydroxybutyrate dehydrogenase (α-HBDH) activities on specimens collected as part of the daily routine. In 34 patients there was an excellent correlation between both methods of analysis. However, the isoenzyme profile provided confirmation of AMI in a further 7 patients. In these patients total CK remained within the reference range (<80 μ 1) or showed borderline increases (80-160 μ/l), although α-HBDH remained normal. Among the remaining 48 patients in which AMI was ruled out. 4 showed elevations in total CK due to non-cardiac conditions. In a further 2 patients, in which total CK remained normal, trace amounts of CK-MB were detected. Both of these patients suffered episodes of atrial fibrillation. The individual assays for each collection period revealed that 61%, of the specimens were positive for CK-MB on the admission sample, whereas 93% were positive by the second specimen. However elevations in total CK ( > 160 μ/l) occurred in only 24% of patients on the first specimen, whereas 68%, were elevated by the second. The ratio of LD1:LD2> 1 occurred in 20% on admission but 85%, by 24-37 h. This coincided with α-HBDH being elevated in 24%, and 78% of patients respectively. Therefore, the combination of CK and LD isoenzyme profiles provided a more rapid and specific indication of AMI. Creatine kinase (CK) and lactate dehydrogenase (LD) isoenzyme activities were measured in 100 patients with suspected acute myocardial infarction (AMI). The method employed was electrophoresis on thin agarose films using the Corning-ACl apparatus and reagents. The usefulness of this procedure as an aid to diagnosis and management was assessed. Specimens were collected at critical times on the enzyme release curve, the first on admission, then at intervals of 6-13 and 24-37 h. A comparison was made using significant elevations in total CK and α-Hydroxybutyrate dehydrogenase (α-HBDH) activities on specimens collected as part of the daily routine. In 34 patients there was an excellent correlation between both methods of analysis. However, the isoenzyme profile provided confirmation of AMI in a further 7 patients. In these patients total CK remained within the reference range (<80 μ 1) or showed borderline increases (80-160 μ/l), although α-HBDH remained normal. Among the remaining 48 patients in which AMI was ruled out. 4 showed elevations in total CK due to non-cardiac conditions. In a further 2 patients, in which total CK remained normal, trace amounts of CK-MB were detected. Both of these patients suffered episodes of atrial fibrillation. The individual assays for each collection period revealed that 61%, of the specimens were positive for CK-MB on the admission sample, whereas 93% were positive by the second specimen. However elevations in total CK ( > 160 μ/l) occurred in only 24% of patients on the first specimen, whereas 68%, were elevated by the second. The ratio of LD1:LD2> 1 occurred in 20% on admission but 85%, by 24-37 h. This coincided with α-HBDH being elevated in 24%, and 78% of patients respectively. Therefore, the combination of CK and LD isoenzyme profiles provided a more rapid and specific indication of AMI.

Changes of metabolism during experimentally induced myotonia of rats: I. Alterations in lactate and malate dehydrogenase isoenzyme activities

Myotonia was induced by administration of 2,4-D ip. After 2 weeks' treatment, the changes in total LDH and MDH activities and their isoenzyme patterns were investigated in muscles of different function and metabolism. To summarize the results, it might be said that in myotonia induced by 2,4-D the metabolism shifts to an anaerobic one in skeletal muscles. The relative hypoxia developing during this period switches on the regulative processes by which tissues acquire an additional possibility for the production of the energy necessary for their function. This was demonstrated by the relative increase in LDH-5 activity. Changes occurring in the heart muscle may be considered as secondary effects which may be due partly to an increased lactate level in the blood, and partly to the toxic effect of 2,4-D.

Hyponatraemia and severity and outcome of myocardial infarction.

A total of 235 consecutive patients admitted to a coronary care unit were investigated for serum electrolyte and urea concentrations; activities of aspartate amino-transferase, lactate dehydrogenase, and lactate dehydrogenase isoenzymes; electrocardiographic changes; clinical state; and outcome. Hyponatraemia, hypochloraemia, and uraemia were common in patients with confirmed myocardial infarctions, the degree of infarction correlating well with all the above indices of severity. The day-to-day variability of plasma sodium, chloride, and potassium concentrations was often increased above normal. Disturbances were greater in patients given diuretics. It is concluded that plasma sodium concentration fall after infarction and that the extent and duration of the fall are indices of the severity of the infarction.

The lactate dehydrogenase isoenzyme pattern in the overacting inferior oblique muscle.

The lactate dehydrogenase (LDH) isoenzyme pattern in normal eye muscles of fetuses, children, and adults in overacting inferior oblique muscles of children was studied and compared. No significant differences were found between LDH isoenzyme activity in the horizontal and vertical recti. Isoenzyme fractions, by percentage, were distributed in these muscles in the order of III greater than IV greater than II greater than V greater than I. A significant difference, however, was noted between the LDH isoenzyme patterns of the inferior oblique muscle in normal adults and children. The percentages were in the orders of III greater than II greater than IV greater than V greater than I, and III greater than IV greater than II greater than V greater than I, respectively. The isoenzyme pattern in the overacting inferior oblique muscles of children was in the order of III greather than II greater than IV greater than V greater than I, identical to that of the adult control group. In addition, the overacting inferior oblique muscle of the children contained more H than M subunit than did the rectus muscle or the normal inferior oblique muscle of children by comparison.

Abnormal lactic dehydrogenase patterns in carcinoma of stomach and in peritumoral tissues.

Segments of gastric mucosa from 32 surgical and biopsy specimens containing gastric carcinoma have been studied to determine the total content of lactate dehydrogenase (LDH). The LDH isoenzyme distribution patterns in tumoral tissues have been compared to that of peritumoral tissue and to the gastric mucosa of a healthy control group. LDH isoenzyme activity in the samples from tumoral tissue was significantly increased. The adjacent peritumoral tissue had a slight increment in the polypeptide M as compared to the distant and normal tissue. This suggests that LDH isoenzyme measurement may prove a valuable addition to histologic study, in the recognition of the tumoral distribution in stomach carcinoma.

Automated kinetic determination of lactate dehydrogenase isoenzymes in serum.

A steady-state kinetic method has been revised for measuring lactate dehydrogenase isoenzyme activities, which relates the inhibition of heart-type isoenzyme activity to the overall isoenzyme composition of the enzyme subunits. The method depends on the pH-dependent formation of an inhibitory ternary complex by the heart-type isoenzyme with NAD+ and pyruvate (if the reaction is measured by NADH oxidation). A preincubation step in the previous method is eliminated. The isoenzymes are measured by measuring the reduction of pyruvate in two different concentrations, which favor either the total or fractional activity, depending on the concentrations of pyruvate and the percentage of heart-type subunits. The method has been adapted to a centrifugal analyzer, which has speeded automated isoenzyme determinations, with an accuracy comparable to that for electrophoretic methods.

Serum activities of hydroxybutyrate dehydrogenase (HBD) and the isoenzymes of lactate dehydrogenase (LD) as an index of traumatic brain injury.

The lactate dehydrogenase (LD), the hydroxybutyrate dehydrogenase (HBD), and the LD isoenzyme activities in serum were followed in the posttraumatic period in 113 patients with cranio-cerebral injury, 70 of whom had verified brain contusion--laceration. In patients with brain contusion the HBD activity, known to be exerted mainly by the anodal LD isoenzyme fractions dominating in brain tissue, was significantly raised in 91% of the blood samples taken within four hours, and in 92% of the samples taken between 12 and 24 hours after trauma, while it was within normal limits in all the samples taken within four hours in patients with brain concussion, and increased in only 17% of the concussion patients 12-24 hours after trauma. The LD1 and the LD1+2 activities were of less diagnostic importance in blood samples taken during the first 24 hours. However, after 24 hours the LD1 activity was as informative as the HBD activity. The LD1 activity was normal in all concussion patients from the third day after trauma, while 78% of the contusion patients still showed raised LD1 activity then. The determination of HBD activity in serum in the immediate post-traumatic period is recommended as an appropriate method for screening parenchymatous brain injury. A complete LD isoenzyme separation may later add some further information in doubtful cases.

Application of nicotinamide-adenine dinucleotide analogs for clinical enzymology: A spectrophotometric method for clinical analysis of lactate dehydrogenase patterns with the use of a nicotinamide-adenine dinucleotide analog

The activities of porcine lactate dehydrogenase(LHD) isoenzymes were analyzed using nicotinamide-adenine dinucleotide(NAD) or its analogs as a cofactor, with varying concentrations of l-lactate from 13 to 530 mM. The greatest differences between H 4-type and M 4-type isoenzymes in reaction rates were observed when their activities were compared in a reaction mixture containing 530 mM lactate and NAD, and also in a system of 13 mM lactate with thionicotinamide-hypoxanthine dinucleotide as a cofactor. The ratio of the LDH activity exerted in the former reaction mixture to that exerted in the latter was termed the N/T value. The N/T values of porcine H 4 and M 4 isoenzymes were 0.49 and 9.33, respectively. The N/T values of other three isoenzymes (H 3M 1, H 2M 2 and H 1M 3) were calculated by assuming that the single subunits H 1 and M 1 contribute one-fourth of the values of 0.49 and 9.33, respectively, and a given isoenzyme which is a combination of four subunits of H and M comprises the sum of their values. The calculated values agreed fairly well with the experimental results. The N/T value method was found to be applicable to human LDH isoenzymes, and sera from various patients were analyzed in comparison with normal sera. The method is particularly suitable for the numerical expression of LDH isoenzyme profiles.

Automated separation and measurement of lactate dehydrogenase isoenzymes.

We describe a totally automated, computer-controlled system for separating and measuring the activity of lactate dehydrogenase (EC 1.1.1.27) isoenzymes. These isoenzymes in tissue extracts were separated on disposable DEAE-cellulose mini-columns. Resolution was complete except that LD-1 was not resolved from LD-2.

Changes in lactate dehydrogenase, LDH isoenzymes, lactate, and pyruvate as a result of feeding low fat diets to healthy men and women

A study was conducted to evaluate the effects on blood lipids and lipoproteins of feeding 21 healthy volunteers, 40–60 yr old, foods commonly eaten in the United States for two 40-day periods. Activities of lactate dehydrogenase (LDH) and LDH isoenzymes, lactate, and pyruvate were monitored. Results showed that LDH activity was significantly lower in all subjects at the end of the 25% fat-calorie period (period I) than at the beginning of the study, but rose above initial levels at the end of the 35% fat-calorie period (period II). While total LDH fell during period I, relative activity of M type subunits of LDH rose significantly in relation to H type in both sexes. This rise is probably indicative of an increase in glycolytic activity as a consequence of the increased intake of dietary carbohydrate. In period I, lactate and pyruvate decreased significantly in males (pyruvate greater than lactate) but not in females. Values for males returned to near initial levels in period II. The ratio of lactate/pyruvate was elevated in both sexes after period I. The greater change in pyruvate relative to lactate with increased dietary carbohydrate suggests increased Krebs Cycle activity. There was a statistically significant positive correlation between lactate, pyruvate, and serum triglyceride for males after they ate the 25% and 35% fat-calorie diets and for females after they ate the 35% fat-calorie diet, but not between lactate, pyruvate, and serum cholesterol for either sex.

New Instrument for Rapid Determination of Activities of Lactate Dehydrogenase Isoenzymes

Lactate dehydrogenase isoenzymes can be distinguished kinetically by the fact that isoenzyme H is strongly inhibited a few seconds after the reaction is started if high concentrations of pyruvate are present, in contrast to the M isoenzyme. A new instrument that exploits this fact can measure both the total activity and the proportion of H isoenzyme in serum or plasma in 8 to 10 s. The instrument consists of a simplified stopped-flow apparatus in which the plasma is assayed for lactate dehydrogenase activity, and an electronic device that measures the rate of the reaction at two pre-set time intervals. The first rate is taken between 0.2 and 0.4 s after the reaction is started, a time at which both isoenzymes are fully active, and at which the rate obtained thus reflects total lactate dehydrogenase activity in the plasma sample. The second rate is measured 4 to 6 s after the start of the reaction, at which time the H isoenzyme has become inhibited and the observed rate compared to the initial rate is therefore proportional to the percentage of H isoenzyme activity in the serum. These two rates are electronically displayed on two three-digit voltmeters, the first display being the total activity, the second a number proportional to the inhibited slope. The percentage of M isoenzyme can then be calculated from the initial and final rate. A total of five to six repeat assays may be done within a minute on 1 ml of plasma or serum. This instrument may be of significant value in following the progress of myocardial infarctions and other diseases.

Lactate dehydrogenase isoenzymes in the larvae of Barathra brassicae and Galleria mellonella during microsporidan infection

Changes in the activities of lactate dehydrogenase isoenzymes in the gut and fat body of Galleria mellonella and Barathra brassicae larvac infected by the microsporidans Nosema plodiae and Pleistophora schubergi were studied by means of dise electrophoresis. In the normal last instar G. mellonella gut and fat body three isoenzymes, LDH-1, LDH-2-3, and LDH-4, and in B. brassicae two isoenzymes, LDH-1 and LDH-2-3, were present. In the fat body of both the animals infected by N. plodiae, the isoenzyme LDH-2-3 increased in activity substantially by the fifth day of infection. The gut LDH isoenzymes were not affected by the microsporidan. The same LDH-2-3 effect could be provoked by some enzymes toxic for G. mellonella larvae such as phospholipase-C and protease preparations.

Unusual Variant of Lactate Dehydrogenase Isoenzymes

Abstract Thirteen electrophoretic bands of lactate dehydrogenase isoenzyme activity were detected in the serum of a 69-year-old Negro woman who died of pseudomonas pneumonia. No evidence of tumor was found at necropsy, and additional studies of the enzymatic activity of crude extracts of liver, lung, spleen, kidney, brain, skeletal muscle, lymph node, and heart revealed 1, 2, 3, 4, and 5 separate isoenzyme bands for lactate dehydrogenase isoenzymes 1, 2, 3, 4, and 5, respectively (a total of 15 isoenzyme bands). Serum and erythrocyte hemolysate from one of two healthy daughters displayed a similar pattern of multiple isoenzyme bands in isoenzymes 2 and 3. The observed pattern is consistent with the heterozygous form of a mutation of the genetic locus controlling synthesis of the M monomer such that two differently charged monomeric proteins are produced, each of which apparently combines with H chains with equal facility, leading to the multiband enzymatic specificity seen.

Serum lactate dehydrogenase isoenzyme activities in patients with asthma

<b>Usher, D. J., Shepherd, R. J., and Deegan, T. (1974).</b><i>Thorax</i>, <b>29</b>, 685-689. <b>Serum lactate dehydrogenase isoenzyme activities in patients with asthma.</b> Increases in the serum activities of several enzymes have been reported in patients with asthma. Liver damage, resulting from altered tensions of oxygen and carbon dioxide in the circulation, has been held to be responsible for the majority of this increase, although it has also been suggested that allergic reactions in the lungs might make some contribution. This communication describes the application of a more specific enzyme assay, the serum lactic dehydrogenase (LDH) isoenzyme pattern, to asthma patients in an attempt to elucidate the source of the increase in enzyme activity. Raised activities of two isoenzymes, LDH-3 and LDH-5, comprised the bulk of the increase in total LDH activity; in contrast, the activities of LDH-1 and LDH-2 were virtually unaltered. Analysis of the distribution of isoenzyme activity in lung tissue homogenate, coupled with knowledge of that in liver, suggested that both tissues contributed towards the effects observed. It appeared probable that the increment in LDH-3 activity arose from lung involvement, whereas the major portion of the increment in LDH-5 activity was derived from the liver.

Pyruvate as Substrate in the Determination of Serum Lactate Dehydrogenase Isoenzyme Activity

Abstract Lactate dehydrogenase isoenzyme activity is usually assessed, after the isoenzymes have been separated, by reactions involving lactate as the substrate. We describe a method for their assessment with pyruvate as the substrate. Precision is adequate as compared to the conventional methodology. Application of this type of approach (measurement of a decrease in fluorescence) to determination of other serum isoenzymes is briefly described.