Improved serum-initiated aspartate aminotransferase assay by inhibition of lactate dehydrogenase with oxamate.
We describe a serum-inititated aspartate aminotransferase (EC 2.6.1.1) assay that obviates the need for added lactate dehydrogenase (EC 1.1.1.27) in the reagent system. Interference from the oxidation of NADH by endogeneous lactate dehydrogenase is eliminated by adding sodium oxamate, a competitive inhibitor of the enzyme. The advantages of oxamate inhibition over lactate dehydrogenase addition are a shorter preincubation period, an increase in the linear range from less than 600 to more than 1400 U/L, no interference from above-normal concentrations of ketoacids, and elimination of bias between serum-initiated and the standard oxoglutarate-initiated assays for aspartate aminotransferase.
D000596:Amino Acids / Q000494:pharmacology*; D001219:Aspartate Aminotransferases / Q000097:blood*; D001322:Autoanalysis; D006801:Humans; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors* / Q000097:blood; D008722:Methods; D010072:Oxamic Acid / Q000494:pharmacology*; D011773:Pyruvates / Q000097:blood
D000596:Amino Acids; D011773:Pyruvates; D007770:L-Lactate Dehydrogenase; D001219:Aspartate Aminotransferases; D010072:Oxamic Acid