Lactate dehydrogenase activity

Bom et al. (2000) demonstrated that ort/20-hydroxyphenylacetaldehyde (4 mmol/L) was much more cytotoxic than coumarin (4 mmol/L) to Chinese hamster ovary cells Kj, a cell line that does not contain cytochromes P450. When both of these compounds were investigated in metabolically active hepatocytes isolated from male Sprague-Dawley rats, ort/20-hydroxyphenylacetaldehyde (0.8 mmol/L) caused a greater cytotoxic response compared with coumarin (0.8 mmol/L). 3-Hydroxycoumarin (0.8 mmol/L), not a product of coumarin epoxidation, did not cause a change in cell viability or an increase in lactate dehydrogenase activity. 

Treatment of male Charles-Foster rats with sublethal doses of xylene (0.2 mL of 5 mmol/L extra-pure xylene solution on alternate days for 30 days isomeric composition not indicated) resulted in slight increases of serum aspartate and alanine aminotransferase and alkaline phosphatase activities and bilirubin concentration (Rana Kumar, 1993). A slight increase in alanine aminotransferase activity was also observed after a 3.5-week treatment of male Wistar rats with zneto-xylene (800 mg/kg bw per day on five days per week, by gavage) (Elovaara et al., 1989). Inhalation exposure of C3H/HeJ mice to /jora-xylenc (1200 ppm [5200 mg/m ], 6 h per day for four days) did not affect the serum alanine or aspartate aminotransferase or lactate dehydrogenase activities, or bilirubin level (Selgrade et al., 1993). 

They stated further that, the new adaptive enzyme catalyzing Reaction 3 appears to be similar to the malic enzyme of pigeon liver, although strictly DPN (instead of TPN)-specific. The coenzyme specificity explains the ready occurrence of Reaction 1. Therefore, the authors showed that exogenous NAD was required for the overall reaction (malic acid -> lactic acid), but because this activity was measured manometrically, they never demonstrated the formation of reduced NAD. Similarly, they did not attempt to show that pyruvic acid was the intermediate between L-malic acid and lactic acid. Instead, the formation of pyruvic acid was inferred from the NAD requirement and because the malic acid dissimilation activity remained constant during purification while the lactate dehydrogenase activity decreased (14). In fact, attempts to show any appreciable amounts of pyruvic acid intermediate failed (22). 

Anders, R. F., Jonas, H. A. and Jago, G. R. 1970B. A survey of the lactate dehydrogenase activities in Group N streptococci. Aust. J. Dairy TechnoL 5, 73-76. 

Simulate these mutants for dogfish M4 lactate dehydrogeanse (6LDH.pdb). After energy minimization, superimpose the wild-type and mutant enzymes and construct their animated kinemage files including views for the complete molecular structures and close-ups of the L-lactate dehydrogenase active site as identified by the ProSite. 

A chronic inhalation RfC of 0.0001 mg chromium(VI)/m3 has been derived and verified by EPA for chromium(VI) particulates (IRIS 2000b). The RfC is based on a benchmark concentration of 0.016 mg chromium(VI)/m3 derived from data for lactate dehydrogenase activity in bronchoalveolar lavage fluid in rats exposed to sodium dichromate (Glaser et al. 1990). 

Samples for determination of lactate dehydrogenase activity (LDH) are taken every 30 minutes and they are a measure for the viability and integrity of the isolated organ. A continuous bile flow throughout the perfusion time is the best measure of the functionally integrity of the organ (typically bile flow of four livers are shown in Fig. 2). Isolated livers without bile flow should be excluded from the final evaluation of the data. 

FIGURE 3 Breakthrough and elution profile for total protein ( ) and L-lactate dehydrogenase activity (O) on an expanded-bed affinity column. (From Lali et al.20 with permission.)... 

Examination of the molecular dynamics (MD) simulation dehydrogenases with substrate and NAD(P)H at the active site shows that only one of the possible quasi-boat conformations exists (Bruice and Lightstone, 1998). The NAC structure in the lactate dehydrogenase active site is associated with the formation of the quasi-boat conformation. In this configuration the distance between the transferring hydride and pyruvate carbonyl is about 1 A shorter when the dihydropyridin ring is in the boat form than in the planar conformation. The closeness of the approach of the reactants in this pretransition state, and... 

A 52-year-old woman with a history of hypertension for 15 years developed acute left flank pain, nausea, and vomiting. On a previous similar occasion 2 weeks before she had had a trace of proteinuria and microscopic hematuria. A contrast-enhanced CT scan of the abdomen had not shown stones, hydronephrosis, or morphological abnormalities. She had had no rash. Her urine contained cocaine. Creatine kinase and lactate dehydrogenase activities were raised and there... 

Pejovic, M., Stankovic, a., Mitrovic, D. R. (1992). Lactate dehydrogenase activity and its isoenzymes in serum and synovial fluid of patients with rheumatoid arthritis and osteoarthritis. 

J. Kikuchi, K. Ariga, T. Miyazaki, K. Ikeda, An Artificial Signal Transduction System. Control of Lactate Dehydrogenase Activity Performed by an Artificial Cell-Surface Receptor , Chem. Lett, 253 (1999)... 

Drent M, Cobben NA, Van Dieijen-Visser MP, Braat SH, Wouters EF. Serum lactate dehydrogenase activity indicator of the development of pneumonitis induced by amiodarone. Eur Heart J 1998 19(6) 969-70. 

After 18 intramuscular injections of Arumalon, a 62-year-old woman with degenerative hip-joint changes developed a severe illness, with fever up to 39 C, swellings of the finger, hand, and knee joints, a rash, leukopenia (1.9 X 10 /1), thrombocytopenia (113 x 10 /1), and increased transaminases and lactate dehydrogenase activity (25). There was a positive lymphocyte transformation test with Arumalon and its constituents, and Arumalon-specific antibodies in the cultured... 

A 35-year-old woman developed calf-pain while taking fen-phen. It resolved when the medications were withdrawn, but her pain returned when fenfluramine was restarted. She had slight rises in aspartate transaminase and lactate dehydrogenase activities and... 

Propylene glycol causes acute hemolysis with raised lactate dehydrogenase activity, and raised bilirubin and plasma hemoglobin concentrations after use of a stock solution during intravenous administration of glyceryl trinitrate (11). 

In a 3-year-old African-American boy with moderate atopic dermatitis, tacrolimus caused raised transaminase and lactate dehydrogenase activities. Tacrolimus was withdrawn on day 29, but no further information was given about their liver function tests (65). 

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