Lactate dehydrogenase isoenzyme patterns in cetaceans.

Serum lactate dehydrogenase (LDH) isoenzyme activity was analyzed in cetaceans. Animals that were treated by i.m. injection and others that received azole therapy had distinctly different LDH isoenzyme profiles. A third distinctive pattern was occasionally observed in clinically normal animals with elevations in total transaminase and LDH activity levels. DH isoenzyme activity patterns were not affected by mild or moderate hemolysis, refrigeration after 24 hr, or freezing for 24 hr with subsequent thawing. However, severe hemolysis produced artifactual changes similar to those observed in individuals that received injections but of a lesser magnitude. DH isoenzyme activity patterns may provide useful corroboration of other clinical findings when diagnostic modalities are limited, especially to differentiate nonspecific enzyme elevation from nonpathologic elevations in serum enzyme concentrations due to i.m. injections or azole therapy.