Effects of phenylhydrazine on the electrophoretic behaviour of L-lactate dehydrogenase isozymes in Ictalurus species (Ictaluridae, Teleostei)

1. The effects of phenylhydrazine on LDH isozyme metabolism were studied in Ictalurus species. 2. Significant alterations were found and these varied for the different tissues studied. 3. The toxic effects of phenylhydrazine were linked to several factors: exposure time; hematocrit values, blood sugar levels; changes in normal metabolism with increased anaerobic glycolysis in some tissues; and energy recovery as a result of the fish's ability to react and its state of health. 4. Some hypotheses are made as to how phenylhydrazine may be dealt with: transformation, deposition and/or elimination