Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.27 (lactate dehydrogenase)
 29,211 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the hamster, heat acclimation reduces liver weight more than it does body weight. Therefore, liver weight constitutes a lower percentage of body weight during exposure to high ambient temperature. This change is not a result of dehydration since water content of the whole body and of the liver is not altered during heat acclimation. However, changes in lactic dehydrogenase isozyme proportions indicate a higher rate of liver degradation during the first 2 wk of heat exposure. These changes are accompanied by enhancement of DNA synthesis which is found to be elevated during the early period of heat exposure and later to fall to the control levels. The enhanced DNA synthesis might be a result of a high rate of tissue regeneration which probably takes place in the organ following the commencement of the degradative processes as was suggested in partial hepatectomy. Since the activity of DNA synthesis is negatively correlated with cyclic AMP levels, it is suggested that cyclic AMP plays some role in controlling hepatic DNA synthesis during heat acclimation.
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PMID:Control of liver size in heat-acclimated hamsters. 19 66

In Langendorff-perfused rat hearts, the perfusion pressure was reduced from 100 cm H2O to 20 cm H2O for 30 minutes to produce a model of global ischemia with a residual oxygen uptake. The release of lactate dehydrogenase (LDH) and the occurrence of ventricular arrhythmias during reperfusion were dependent on the substrate. Glucose-perfused hearts had the highest rates of glycolytic ATP production (2.5 mumol/g per min) during ischemia with normal contents of tissue cyclic adenosine 3',5'-monophosphate (cAMP) and, during reperfusion, the release of LDH was lowest and severe ventricular arrhythmias did not occur. In pyruvate-perfused hearts, glycolysis was inhibited during ischemia, the rate of production of glycolytic ATP was only 0.5 mumol/g per min. and tissue cAMP doubled; during reperfusion, LDH release was 14-fold higher and ventricular arrhythmias were more severe. Total tissue contents of ATP and phosphocreatine were similar in glucose- and in pyruvate-perfused hearts. In hearts perfused with acetate, there was virtually no glycolytic ATP synthesized during the last 5 minutes of ischemia and cAMP increased further. Acetate- and palmitate-perfused hearts showed greatest release of LDH and had severest arrhythmias during reperfusion, suggesting that it was the metabolic and not the detergent effects of palmitate that were operating. Lipolysis was not a major factor in the cause of reperfusion LDH release. A role of glycolytic ATP in the maintenance of membrane integrity is postulated.
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PMID:Effects of substrates on tissue metabolic changes in the isolated rat heart during underperfusion and on release of lactate dehydrogenase and arrhythmias during reperfusion. 20 59

The muscle-type (M4) lactate dehydrogenases of Sebastolobus altivelis, a deep-water scorpaenid, and S. alascanus, a shallower species, are electrophoretically indistinguishable, yet differ in pressure sensitivities. The lactate dehydrogenase of S. altivelis exhibits lower pressure sensitivities of substrate and coenzyme binding and catalytic rate. Such apparently pressure-adaptive kinetic properties may be important for establishing species depth zonation patterns in the ocean.
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PMID:Pressure-adaptive differences in lactate dehydrogenases of congeneric fishes living at different depths. 20 49

The effects of three widely spaced levels of bacterial contamination of reagent water on several chemistry, radioimmunoassay, and coagulation procedures were studied. These included determinations of lactate dehydrogenase, creatine kinase, aspartate transaminase, alkaline phosphatase, blood urea nitrogen, total protein, thyroid-stimulating hormone, digoxin, thrombin time, activated partial thromboplastin time, and prothrombin time. Statistical analyses included calculations of means and coefficients of variation, and analysis of variance, as well as correlation coefficients for test results versus logarithm of bacterial contamination. Statistically and clinically significant differences occurred together only for an elevated level of creatine kinase.
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PMID:Effects of bacterial contamination of reagent water on selected laboratory tests. 43 36

Exposure to drinking water containing as much as 500 ppm aluminum chloride for periods of 30, 60, and 90 days had no apparent effect on male reproductive processes. In an attempt to correlate enzyme activity with particular spermatogenic cell types, postnatal development of testicular enzymes was studied. Eight enzymes were selected: hyaluronidase (H), lactate dehydrogenase isoenzyme-X (LDH-X), dehydrogenases of sorbitol (SDH), alpha-glycerophosphate (GPDH), glucose-6-phosphate (G6PDH), malate (MDH), glyceraldehyde-3-phosphate (G3PDH), and isocitrate (ICDH). Enzyme specific activities in testicular homogenates were determined. Two types of enzyme developmental patterns were observed. One was represented by H, LDH-X, SDH, and GPDH; and the other by G6PDH, MDH, G3PDH, and ICDH. The former was characterized by a change in enzyme activities from low in newborn to high in adult while in the latter this pattern was reversed. The two complementary enzyme systems crossed each other at puberty. Prior to puberty, only spermatogonial cells are present; sperm differentiation initiated at puberty adds spermatocytes and spermatids to the testicular cell population. Male rats were exposed to borax in their diet for periods of 30 and 60 days. Concentrations of boron were 0, 500, 1000, and 2000 ppm. At the end of each experimental period, the specific activities of the selected enzymes were determined in the testis and prostate. Correlations of enzyme activity with testicular histology and androgen activities of the male accessory organs were sought. In addition, plasma FSH, LH, and testosterone levels were measured to assess pituitary-testicular interaction. Plasma and testicular boron concentrations were determined and a minimum boron concentration which induced germinal aplasia and male infertility was estimated. In both 30 and 60 day feeding studies, male rats receiving 500 ppm failed to demonstrate any significant adverse effects. In contrast, male rats receiving 100 and 2000 ppm boron displayed a significant loss of germinal elements, although most of the Leydig and Sertoli cells appeared normal. Testicular atrophy was associated with a decrease in seminiferous tubular diameter and a marked reduction of spermatocytes and spermatogenic cells. These morphologic alterations were associated with a concomitant reduction of H, SDH, and LDH-X specific activities. In contrast, the specific activities of G3PDH and MDH were significantly elevated above control. The increase in these enzyme activities can be attributed to the relative enrichment of spermatogonial cells during the loss of spermatocytes and spermiogenic cells. Boron-induced male germinal aplasia was also associated with significantly elevated plasma FSH while plasma LH and testosterone levels were not significantly altered. Plasma testosterone levels were unaltered. Male fertility studies demonstrated that at the 500 ppm boron level, fertility was unaffected. However, at 1000 and 2000 ppm boron, male fertility was significantly reduced. Most effects were reversible within 5 weeks. However, the male group receiving 2000 ppm boron for 60 days remained sterile. There was no dose-related decrease in litter size or fetal death in utero. Therefore, the boron-induced infertility was apparently not due to a dominant lethal effect but rather to germinal aplasia. Boron appears toxic to spermatogenic cells at testicular concentrations of 6-8 ppm.
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PMID:Assessment of environmental factors affecting male fertility. 44 58

Hilar drainage fluid of dog kidneys was analyzed as an approximation to renal extracellular fluid after preservation by flushing with chilled high K-low Na solution (Collins C4) followed by ice-cold storage for 24 and 48 hr in a bath of flushing medium. Compared with the medium, Na and Cl were increased to 30 mM/liter and K decreased slightly to 93 mM/liter. Glucose decreased, whereas lactate, lactic dehydrogenase, and creatine phosphokinase increased by significant amounts in both the drainage fluid and bath. The inulin space of the undrained kidney average 37% of wet weight. Calculated intracellular Na and Cl concentrations averaged 50 and 37 mM/kg cell water while K remained within normal limits. A significant fraction of red blood cells retained during initial flushing entered the effluent during storage. Bath and effluent composition of a human cadaver kidney approximated those of a dog.
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PMID:Extracellular fluid of the kidney preserved by the Collins technique. 46 28

Brain edema fluid was collected from cats with a freezing lesion in the left parietal cortex by the insertion into the brain of needles containing nylon wicks and connected to polyethylene tubes. The edema fluid samples which accumulated in the polyethylene tubes were regularly analyzed for Na+ and K+ content, colloid osmotic pressure, lactate dehydrogenase and creatine phosphokinase activity, and 99mTc-albumin radioactivity; the albumin tracer being introduced intravenously at the time of cold-injury. One series of cats received an intracerebral injection of ouabain solution, the control series an intracerebral injection of saline, at 100 min after the cold-injury. The ouabain injection was followed by an increase of K+ content, LDH and CPK activities but a decrease of Na+ concentration in the edema fluid, attributable to a concentration of solutes in the edema fluid as presumably water and Na+ were shifted into the cells and hence the extracellular space was reduced.
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PMID:The effect of intracerebral ouabain administration on the composition of edema fluid isolated from cats with cold-induced brain edema. 48 57

A method for the detection of lactic dehydrogenase enzymatic activity in outer hair cells of the rabbit is described. The membranous labyrinth with temporal bone was prefixed in glutaraldehyde. After being placed into the incubation medium, it was postfixed in osmium tetroxide. Specimens of the organ of Corti were removed. Then the specimens were embedded in water-soluble glycol and cut with a cryostat for light microscopy, and also they were embedded in Epon and cut for light and electron microscopy. Sectioning of the membranous labyrinth was very easily made when the specimens were embedded in both the water-soluble glycol and the Epon. The structures of the frozen sections as well as the Epon-embedded ones were well preserved. In the frozen sections the preservation and localization of reaction products were thoroughly kept, but monoformazan of the Epon-embedded sections was soluble.
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PMID:A detection method for lactic dehydrogenase activity in the inner ear. 65 36

Reaction of adenosine 5'-monophosphate (Ado-5'-P) with bromine at pH 4.0 yielded 8-bromo-adenosine 5'-monophosphate and following reaction with several alpha,omega-diaminoalkanes gave the corresponding 8-(omega-aminoalkyl)-Ado-5'-P derivatives. Condensation of these analogues with N-trifluoroacetyl-glycine or beta-alanine in the presence of a water-soluble carbodiimide generated several 8-substituted derivatives. These analogues: (see article) comprised an 8-substituted Ado-5'-P ligand to which a spacer molecule of similar length but differing hydrophobicity was attached. The derivatives were purified, characterised and attached to CNBr-activated Sepharose. The chromatographic behaviour of the resulting absorbents was investigated in terms of their ability to bind both lactate and alanine dehydrogenase. The enzymes bound tighter to the more hydrophobic derivatives with the strength of the interaction decreasing with increasing hydropholicity. The effect of the introduction of a single hydroxyl group in the spacer arm was also studied with several enzymes known to exhibit anomalous behavior on affinity chromatography. In free solution, (Ado-5'-P)-8-NH CH2CH2CH2CH2CH2CH2NH2 and (Ado-5'-P)-8-NH CH2-CH CH2NH CO CH2NH2 were competitive with NADH for rabbit muscle lactate dehydrogenase, (see article) with Ki values of 2.0 and 1.8 mM respectively. These data suggest a difference in accessibility of the hydrophobic and hydrophilic derivatives when attached to Sepharose rather than a fundamental difference in affinity. This suggestion is supported by the fact that there is no obvious correlation between the Ki values in free solution of a series of 8-(omega-aminoalkyl)-Ado-5'-P derivatives of increasing chain length, and hence hydrophobicity, and their chromatographic behaviour when immobilised. The data suggest that the hydrophobicity/hydrophilicity of the spacer arm determined the accessibility of the immobilised ligand to interaction with the complementary enzyme.
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PMID:The synthesis of several 8-substituted derivatives of adenosine 5'-monophosphate to study the effect of the nature of the spacer arm in affinity chromatography. 83 41

Changes in normal human leg lymph protein concentration, output, and lymph flow/lymph protein concentration relationship, as well as lactate dehydrogenase and alkaline phosphatase activity were followed during procedures known to increase capillary filtration as venous stasis, muscular exercise and warming of tissues. Lymph flow increased by 83% during two hour ergometer cycling, and by 117% during two hour warm water foot bath. During a two hour period of venous stasis lymph flow dropped by 50%. There was an increase in lymph flow during the rest period following all three types of experiment, most pronounced after foot warming. An inverse relationship between the lymph flow rate and lymph protein concentration was found. Lymph enzymes followed the same pattern of changes as total protein.
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PMID:Flow and composition of leg lymph in normal men during venous stasis, muscular activity and local hyperthermia. 84 71


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