Tissue enzyme activities following exposure to dietary mirex in the channel catfish, ictalurus punctatus

Young channel catfish Ictalurus punctatus were exposed to 1, 100, 200 and 400 ppm dietary mirex. Specific activities of lactic dehydrogenase, malic dehydrogenase, glutamate pyruvate transaminase and glutamate oxaloacetate transaminase were determined in brain, gill, liver and muscle at one, two, three and four weeks. Few changes in enzyme sppecific activities were found which were attributed to mirex exposure. It appears that mirex, even at high dietary exposure levels, is relatively innocuous to these enzyme activities.