[Human erythrocyte lactate dehydrogenase activity changes in the presence of some alcohol dehydrogenase inhibitors]

The aim of the study was to evaluate the effect of alcohol dehydrogenase (ADH; E.C. 1.1.1.1) inhibitors and substrates: cimetidine, 4-methylpyrazole (4MP), EDTA, ethanol and methanol on lactate dehydrogenase (LDH; E.C. 1.1.1.27) activity. The activity of LDH was spectrophotometrically determined in in-vitro prepared diluted hemolysates obtained from human erythrocytes with mentioned compounds at the concentrations 0.01, 0.1, 1.0 mM of cimetidine, EDTA, 4MP and 12.5, 25.0, 50.0 mM of ethanol and methanol. The reaction was conducted at 37 degrees C in pH 7.5 and changes of optical density was measured at lambda = 340nm. LDH activity was significantly inhibited by 0.10 mM (p < 0.05) and 1.0 mM (p < 0.01) of cimetidine and EDTA. There were no observed any significant changes vs. control in LDH activity when 4MP, ethanol or methanol was added to environment of reaction.