Enzymatic relationship between human Tγ+ lymphocytes and thymocytes

The lactate dehydrogenase isoenzyme pattern has been determined in human thymocytes and in peripheral blood T lymphocytes, Tγ⁺, and Tμ⁺ lymphocytes. Thymocytes have a highly significant lower activity in LDH-1 and LDH-2 together with a highly significant higher activity in LDH-3 and LDH-4 than peripheral T lymphocytes. The same differences are seen when Tγ⁺ and Tμ⁺ cells are compared. On the contrary there are almost no differences in pattern between the peripheral T lymphocytes and Tμ⁺ cells on one hand and between thymocytes and Tγ⁺ cells on the other hand. These findings suggest that both thymocytes and Tγ⁺ cells exhibit a very immature LDH pattern with regard to the Tμ⁺ cell population.     

Effect of high carbohydrate diet on serum lactate dehydrogenase isozyme pattern in Japanese young men

Changes in the activity of serum lactate dehydrogenase (LDH) and the serum LDH isozyme pattern in healthy young men given a high carbohydrate diet (480-636 g/day, 80% of the total energy) for 21 days were examined. Serum total LDH activity showed no significant change in four healthy young volunteers who received high carbohydrate diet for 21 days. However, the percentage of LDH-4 increased significantly (P less than 0.01) from 8.5 +/- 2.4 to 10.9 +/- 1.9% after 21 days, as did also the percentage of LDH-5 (P less than 0.01) from 5.1 +/- 1.9 to 10.7 +/- 2.9%. The percentage of M-type LDH activity increased 30% during the experiment (P less than 0.05). It is concluded from the results that the high carbohydrate intake affects the percentage of LDH-4 and LDH-5, but not the total serum LDH activity.     

Changes in the lactate dehydrogenase isoenzyme spectrum during T-lymphocyte differentiation

The pattern of lactate dehydrogenase isoenzyme spectrum changes on different stages of T-lymphocyte differentiation was studied An enriched population of stem cells has LDH-5, 4 and 3 isoenzymes, and much less LDH-2 activity. The isoenzyme pattern of thymic cell precursors consists of LDH-5, 4, 3 and 2. All the five LDH isoenzymes were found in cortical thymocytes. Medullary thymocytes reveal LDH-5, 4 and 3 isoenzymes. T-lymphocytes of peripheral lymphoid organs contain mainly LDH-5 and in a lesser degree LDH-4 activity.     

Variance in LDH isozyme patterns in a Chinese hamster (Cricetulus griseus) colony.

1. LDH activity and isozyme pattern were examined in the liver and epididymal fat pad of animals in 12 different sublines of the Upjohn Chinese hamster colony, which was established to produce animals with spontaneous diabetes. 2. Considerable divergence was observed and the animals could be divided into 3 groups according to LDH-H activity. Each group was significantly different from the other in epididymal fat pad LDH-1, 2,3 and 5 and liver LDH-3, 4 and 5. 3. The variance in LDH isozyme pattern bore no relationship to the state of diabetes but appeared to arise from other genetic determinants. However, within a single subline, a significant correlation between blood sugar and epididymal fat pad LDH-5 was observed.     

Combined analysis of serum lactic dehydrogenase levels and isozyme patterns in ovarian neoplasms

A total of 65 cases of ovarian tumor admitted for surgical intervention were prospectively enrolled in this study, including 40 cases with benign ovarian tumors and 25 cases of ovarian cancer. The 25 malignancies were comprised of 22 cases of common epithelial origin and three cases with Krukenberg tumors. Serum total LDH level and its isozyme activity were measured preoperatively in each patient. The mean value (+/-SD of serum LDH in the malignant group was 876.3 (+/- 450.4) IU/1, which was significantly higher than 364.8 (+/- 87.9) IU/1 in the benign group. Twenty-two cases of ovarian malignancy (88%) and 6 cases of the benign group (15%) had elevated serum LDH levels above 450 IU/1. Analysis of the LDH isozyme pattern demonstrated that there was a significant shift to LDH-4 and LDH-5 fractions in ovarian malignancy when compared to the benign group (with the mean value of 9.5%, 14.6% vs. 6.5% and 4.6%, respectively). The elevated LDH level could yield 88% and 85% in sensitivity and specificity for detecting ovarian malignancy, while the abnormal isozyme pattern could yield 84% and 77.5%, respectively. From combined analysis of total LDH levels and isozyme patterns, the true positive detection rate and true negative detection rate could both reach 100%. In conclusion, the present findings imply that total serum LDH level and isozyme activity measurement may provide significant aids in evaluation and detection of human ovarian cancers among patients with ovarian tumors.     

Lactate dehydrogenase isozymes in type I,IIA and IIB fibres of rabbit skeletal muscles

Summary Lactate dehydrogenase (LDH) isozyme patterns were analysed by polyacrylamide (PAA) slab gel electrophoresis in extracts prepared from various rabbit skeletal muscles of defined fibre composition and by PAA microelectrophoresis of microdissected, histochemically typed single muscle fibres. The results obtained by electrophoresis of whole muscle extracts generally agreed with the data obtained from single fibre electrophoresis, i.e. the LDH isozyme pattern corresponded to that of the predominant fibre type. Type I Fibres from soleus and semitendinosus muscles were characterized by a unique pattern of all 5 LDH isozymes with a predominance of LDH-1, 2 and 3. The major fraction (80%) of the type II fibres from extensor digitorum longus and tibialis anterior muscles contained only LDH-5 (M₄). About 20% of the type II fibres contained in addition to LDH-5 small amounts of LDH-4 and LDH-3. The fraction of fibres containing LDH-5, LDH-4, and LDH-3 was similar (ca. 20%) in the histochemically defined IIA and IIB subpopulations In view of the fact that the major fractions of rabbit IIB fibres display low and of IIA fibres high aerobic oxidative capacities (Reichmann and Pette 1982), these data indicate that the expression of the H-subunit of LDH is not correlated with the aerobic-oxidative capacity of the fibre. It also appears not to be correlated with the presence of different myosin isoforms in IIA and IIB fibres.     

Significance of the variation in isozymes of liver lactate dehydrogenase with thermal acclimation in goldfish--I. Thermostability and temperature dependency.

1. Total and isozyme properties as well as isozyme pattern were examined in liver lactate dehydrogenase (LDH) from goldfish acclimated to different temperatures. 2. LDH of warm-acclimated fish were thermostable and exhibited higher Q10 in low temperature range as compared with that of co ld-acclimated fish. 3. The relative activities of LDH-1, LDH-2 and LDH-3, which were more thermostable, increased and LDH-4 and LDH-5, which were more heat sensitive, decreased during warm acclimation. Q10 in the low temperature range for LDH-5 was lower than that for LDH-1.     

Lactate dehydrogenase isoenzymes in diabetic patients

Lactate dehydrogenase (LDH) isoenzyme profiles in human platelets and the sera of patients with type I and II diabetes mellitus and vascular complications, as well as normal subjects were measured utilizing a recently established, modified micromethod. LDH-3 was the predominating species in platelets (37.5 +/- 3.0%), with LDH-2, 1, 4 and 5 following in decreasing order of concentration. The LDH-3/LDH-4 ratio in platelets varied from 6.2 to 1.38. Type I and type II diabetic patients with vascular complications showed a significantly higher ratio for LDH-3/LDH-4 (3.99 +/- 1.20 for DM I, 2.16 +/- 0.25 for DM II patients) than the mean ratio for normal subjects (1.14 +/- 0.08). This platelet-specific LDH isoenzyme pattern may be the result of frequent in vivo platelet-vessel wall interactions in the diabetic patients whose platelets are known to be hyperaggregable in in vitro test systems. Since non-diabetic patients patients with vascular complications also displayed a similarly elevated LDH-3/LDH-4 ratio, a wider classification is preferable, although the measurement of the LDH isoenzyme pattern will be helpful in assessing diabetic vascular complications.     

Carbohydrate energy metabolism in Fasciola gigantica (trematoda)

Umezurike G. M. and Anya A. O. 1980. Carbohydrate energy metabolism in Fasciola gigantica (Trematoda). International Journal for Parasitology10: 175–180. Adult Fasciola gigantica contained 4.49 ± 0.06 % (mean ± S.D.) wet weight glycogen. Tissue homogenates contained high levels of malate dehydrogenase (MDH), NAD-linked malic enzyme (ME), Phosphoenolpyruvate carboxykinase (PEPCK) and lactate dehydrogenase (LDH). MDH, PEPCK and ME activities appeared to be localized in both cytosolic and mitoehondrial fractions, fumarase activity appeared to be predominantly mitochondrial whereas LDH and pyruvate kinase activities were cytosolic in distribution. Polyacrylamide gel electrophoresis revealed the predominance of LDH-1, LDH-2 and LDH-3 but only traces of LDH-4 and LDH-5 isoenzymes in the crude cytosolic fraction. LDH activity in the crude sample was inhibited by excess substrate (pyruvate). The mitoehondrial system showed NADH -cytochrome c oxidoreductase, succinate-cytochrome c oxidoreductase, NADH oxidase and some cytochrome c-oxygen oxidoreductase activities. Under anaerobic conditions, NADH-fumarate oxidoreductase and succinate-NAD + oxidoreductase activities of mitoehondrial preparations were stimulated in the presence of ADP and ATP respectively. Isolated mitochondria contained rhodoquinone and no ubiquinone, and isolated rhodoquinone was readily reduced by succinate in the presence of submitochondrial particles. Hydrogen peroxide was produced by submitochondrial particles in the presence or absence of KCN or in the presence of fumarate.     

Lactate dehydrogenase of concentric zones of human senile cataracts and calf lenses produced by ultrasound

Cataractous lenses from men and women averaging 77.7 years of age were sonicated for intervals of 10 min with 0.85% saline under cooling in a laboratory sonicator, followed by centrifugation. The respective supernatants were analyzed for LDH and the weights of the zonal portions obtained by difference. The initial fraction averaged 60 and 47% in solids and LDH, respectively, with decreasing contents to the final harder core residue. The procedures were also applied to calf lenses. Much shorter sonication periods and stepwise increases in wattage from one fraction to the next were also investigated. The calf lens displayed higher LDH activity/mg at settings of 6-8 W in contrast to the cataracts, the initial fraction containing 80% of the enzyme activity and the solids; the values were far lower at settings of 1-3 W. As compared to the sonicated outer layer fractions, the calf nuclear portions showed small but significant decrements in the isoenzymes, LDH-1 and LDH-2, and increases in LDH-4 and LDH-5, possibly indicative of heightened anaerobiasis.     

Significance of the variation in isozymes of liver lactate dehydrogenase with thermal acclimation in goldfish--II. Effect of pH.

1. Effect of pH on liver lactate dehydrogenase (LDH) and its isozymes was examined in the goldfish acclimated to different temperatures and some purification of the LDH was attempted. 2. The optimal pH and the Km value at 30 degrees C of the enzyme were independent of acclimation temperature. 3. the optimal pH of isozyme was more basic in the order of LDH-1, LDH-2, LDH-3, LDH-4 and LDH-5. Km values of isozymes at 30 degrees C were higher in the order of LDH-1, LDH-3 and LDH-5. 4. There was no change in the enzyme activity during thermal acclimation.     

L.D.H. and L.D.H. isoenzymes of the intra-uterine secretions of the cow during the estrous cycle

Uterine secretions were collected from 20 mature cows during estrus (day 0), metestrus (day 5), diestrus (day 10) and proestrus (day-1). Lactate dehydrogenase (LDH) and LDH isoenzymes activity were evaluated. No significant cyclic variations of LDH activity was found in the uterine secretions while the mean of the enzyme activity was higher during the estrogenic period of the cycle. The relative activity of LDH-1, LDH-2 and LDH-3 isoenzymes were higher during proestrus and estrus whereas LDH-5 activity was more important during metestrus. The LDH-3 seems to have the higher relative activity in uterine secretions of the cow.     

Cell-marker studies in CLL with monoclonal OKT antisera and lactic dehydrogenase isoenzyme analysis

In 16 patients with B-type CLL, the T and B cell compartment was analysed using the monoclonal anti-T-cell antisera OKT1, 3, 4 and 8 and the lactic dehydrogenase enzyme marker. Pertinent findings were: the presence on the CLL cells in 15 out of 16 patients of the antigen determined by the OKT1 antiserum, and, in all patients, a lower total LDH content on a per cell basis combined with a higher percentage-activity in the LDH-3 band as compared to the normal B-cell. Furthermore, the T-cell compartment was also disturbed in these patients, as the ratio of OKT4+ to OKT8+ cells was significantly depressed accompanied by a significant decrease of the LDH-1 percentage-activity in favour of LDH-3 and 4. These findings argue for the B-cell being immature and confirm the recent evidence that the T-cell compartment is changed in B-CLL.     

Expression of lactate dehydrogenase isozyme 5 (LDH-5) in cultured mouse blastocysts in the absence of implantation and outgrowth

Extensive extraction studies with Triton X-100 revealed only LDH-1 (B₄) but no trace of LDH-5 (A₄) in one-cell and two-cell mouse and rat embryos. The LDH isozyme pattern of preimplantation mouse embryos changes from the maternally inherited B subunit isozyme (LDH-1) to a pattern dominated by LDH-5 when mouse blastocysts are cultured under conditions that prevent hatching but allow trophoblast giant cell transformation. During differentiation of mouse blastocysts in vitro, implantation is therefore not essential for the appearance of the A subunit form of LDH (LDH-5) coded for by the embryonic genome. Mechanisms controlling the expression of LDH-5 in mouse blastocysts during in vivo development are discussed.This work was supported by grants of the Deutsche Forschungsgemeinschaft awarded to the Sonderforschungsbereich 29—Embryonale Entwicklung and Differenzierung.     

Additional lactate dehydrogenase (LDH) isoenzymes in normal testis and spermatozoa of adult man

Summary Adult human testicular tissue contains up to six previously undescribed lactate dehydrogenase (LDH) isoenzymes in addition to the five LDH isoenzymes normally found and the sixth found in spermatogenic cells and spermatozoa, LDH-X. Additional LDH isoenzymes were also found in spermatozoa but not in seminal fluid or in serum. After electrophoresis one additional LDH isoenzyme of testicular tissue was localized between LDH-1 and LDH-2, two between LDH-2 and LDH-3, two between LDH-3 and LDH-4, and two between LDH-4 and LDH-5. These localizations indicate that the additional LDH isoenzymes are tetramers combining the A and B subunits of the five normal LDH isoenzymes and the C subunit of LDH-X. The additional LDH isoenzymes may be important in the metabolism of spermatogenic germ cells and spermatozoa.     

Ferritin-bearing lymphocytes and T-cell levels in peripheral blood of patients with breast cancer

Summary Peripheral blood lymphocytes bearing surface ferritin and thymus-dependent lymphocyte (T cell) levels were determined in 15 breast cancer patients in stage I–II, 5 in stage III, 10 with benign breast disease, 4 with Thalassaemia, and 25 normal controls. The results of this study demonstrate that a subpopulation of lymphocytes (16.6%) bearing surface ferritin was found in patients with breast cancer in stage I–II. None were demonstrated in patients with either benign breast disease, or with Thalassaemia, the latter known to have high serum ferritin levels, and almost none (1.7%) in normal individuals. A significant decrease in the percentage of ERFC as compared with the percentage of T cells, determined with anti-T cell antiserum (P<0.01), was observed in patients with breast cancer in stage I–II. Yet, the mean T-cell percentage in this group of patients was significantly higher than the mean percentage of T cells in normal controls (P<0.01). In patients with benign breast disease, the percentage of T cells corresponded to the percentage of ERFC and did not significantly differ from those in normals. Stage III breast cancer patients seem to constitute a biologically distinct group, since the ferritin-positive lymphocyte subpopulation disappeared and the percentage of ERFC and T cells returned to the values of normal controls.Overnight incubation of lymphocytes from patients exhibiting a ferritin-positive lymphocyte subpopulation in culture media containing 20% FCS resulted in the removal of ferritin from the surface of the cells and in restoration of the percentage of ERFC.     

生殖器疱疹初发患者外周血淋巴细胞检测结果分析

目的检测生殖器疱疹初发患者（GH）外周血T淋巴细胞亚群、NK细胞和B细胞的表达水平,探讨其发病机制与细胞免疫功能之间的关系。方法应用流式细胞仪检测20例初发生殖器疱疹患者外周血T淋巴细胞亚群、NK细胞和B细胞的表达水平,并与60例复发性生殖器疱疹患者（RGH）、35例健康对照者外周血检测结果相比较。结果（1）初发组和对照组相比,除NK细胞降低差异有显著性外,其他差异无显著性;（2）初发组与复发组相比,初发组T细胞、CD4^＋细胞、CD4^＋／CD8^＋均高于复发组,CD8^＋细胞百分比低于后者,差异有显著性;B细胞、NK细胞比例差异无显著性;（3）复发组与对照组相比,外周血中T细胞、CD4^＋细胞、NK细胞所占比例,CD4^＋／CD8^＋均降低,差异有显著性;CD8^＋细胞百分比升高,差异有显著性;B细胞比例差异无显著性。结论生殖器疱疹初发患者存在细胞免疫功能异常。     

Additive effects of antitumor drugs and lymphokine-activated killer cell cytotoxic activity in tumor cell killing determined by lactate-dehydrogenase-release assay

Summary The effect of pretreatment with antitumor drugs on lymphokine-activated killer (LAK) cell cytotoxic activity, determined by lactate-dehydrogenase(LDH)-release assay, was investigated. LAK cells were induced by incubating peripheral blood lymphocytes of healthy donors in medium containing interleukin-2 (IL-2) and monoclonal anti-CD3 antibody for 6–7 days. A human lung squamous carcinoma cell line, SQ-5, was used as an adherent target. After 24 h exposure of the target cells to cisplatin, doxorubicin, or mitomycin C, the drugs were washed off and LAK cells were added at an E/T ratio of 5. During further incubation for 48 h, LDH release from cisplatin- or doxorubicin-pretreated target cells was markedly higher than that from non-pretreated target cells. The combination of cisplatin and LAK cells has an additive cytotoxic effect and that of mitomycin C and LAK cells does not; there may also be an additive effect late in the toxicity mechanism between doxorubicin and LAK cells.     

Purine salvage pathway enzyme activities in human T-, B-, and null lymphocyte populations

Deficiencies of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) result in distinctly different immunodeficient states. In order to better understand the roles of these two purine salvage pathway enzymes in normal immunity we have characterized their activities in peripheral blood T-, B-, and null (non-T, non-B) cell populations. We have found that T lymphocytes have significantly higher ADA activity than B or null cells (P < 0.001) only when expressed as a function of cell protein. Contrary to other reports B lymphocytes cannot be distinguished from T lymphocytes on the basis of PNP activity. When the enzyme activities are expressed per cell number null cells have a much higher PNP activity (mean ± SD = 461 ± 174 ng/hr/10⁶ cells) than either T (57 ± 10) or B (93 ± 51) lymphocytes (P < 0.001 and 0.002, respectively). Null cells also have a significantly greater protein content per cell (55.0 ± 9.6 μg/10⁶ cells) than T (13.3 ± 4.6) or B (18.7 ± 13.8) lymphocytes. When expressed as a function of cell number null cells have a higher mean, though not statistically significant, ADA activity than T and B lymphocytes. These results indicate that normal human peripheral blood T, B, and null cells can be distinguished on the basis of their ADA and PNP activities and that the method of expression of the activities is critical. The significantly higher PNP activity and protein content per cell in null lymphocytes is compatible with a less differentiated cell population which may include B- as well as T-cell precursors.     

Selective inactivation of lactate dehydrogenase of rat tissues by sodium deoxycholate.

Soluble lactate dehydrogenase (EC 1.1.1.27) extracted from brain, skeletal and cardiac muscle and liver of rats, and purified isoenzymes LDH-1 and LDH-5, were incubated with sodium deoxycholate. Deoxycholate almost totally inactivated isoenzyme LDH-5 (A4), whereas it left isoenzyme LDH-1 (B4) unaffected. Tissue lactate dehydrogenase was inactivated to different degrees depending on the origin of the enzyme. Electrophoretic isoenzyme studies of tissue lactate dehydrogenase showed the loss of activity to be quantitatively related to the overall percentage of subunit A distributed among the homotetramer LDH-5 and the heterotetramers LDH-2, LDH-3 and LDH-4. It was concluded that subunit A of lactate dehydrogenase interacts selectively with deoxycholate, irrespective of its association with subunit B. Distinct changes in electrophoretic mobilities of deoxycholate-treated isoenzymes strongly indicated an indiscriminate binding of deoxycholate by all LDH isoenzymes, probably through hydrophobic interactions. The results suggest that the inactivation of the enzyme is non-competitive, but the basis of the selectivity of deoxycholate towards subunit A is not known at present.