Analysis of liver aldehyde dehydrogenase isoenzymes using high-performance (pressure) liquid chromatography

Methods for separation of isoenzymes using high-performance (pressure) liquid chromatography have been adapted for analysis of aldehyde dehydrogenase (ALDH) (aldehyde:NAD oxidoreductase; EC 1.2.1.3) isoenzymes in canine liver. Two major peaks (peaks 1 and 3) and one minor peak (peak 2) of ALDH activity can be detected using ion-exchange chromatography and a continuous-flow analyzer. The elution profiles of ALDH activity in liver homogenates correspond with profiles obtained from isolated ALDH isoenzymes. Varying the composition of the ALDH assay reagents results in changes in the elution profiles consistent with the kinetic properties of the individual isoenzymes. Changes in elution profiles could be detected in liver samples following either in vitro or in vivo treatment with disulfiram (Antabuse). HPLC analysis may be a useful method to identify drug and genetic effects on ALDH isoenzymes and to investigate the mechanisms of altered aldehyde oxidation in animals.