Comparison of three serum alpha-hydroxybutyrate dehydrogenase procedures for lactate dehydrogenase isoenzyme discrimination.

Three recently proposed methods for the assay of alpha-hydroxybutyrate (2-oxobutyrate) dehydrogenase (HBD) activity in serum were assessed to determine which one would give the most useful discrimination between the lactate dehydrogenase (LD) isoenzymes. The 2-oxobutyrate concentration and temperature for these procedures were 3.3 mmol/l at 30 degree C, 12 mmol/l at 30 degree C and 15 mmol/l at 37 degree C. LD isoenzyme activity values obtained by thin-layer agarose electrophoresis were compared with HBD activity results by linear regression analysis. The best, statistically significant, correlation of LD-1 with HBD activities was obtained with 3.3 mmol/l at 30 degree C (regression coefficient, 0.92; correlation coefficient, 0.98).