Enlarged livers and hepatic microsomal mixed-function oxidase components in tumor-bearing brown bullheads from a chemically contaminated river

Abstract

Abstract Hepatic mixed-function oxidase (MFO) components in tumor-bearing brown bullheads (Ictalurus nebulosus) from a chemically contaminated river and in bullheads from two relatively uncontaminated sites were compared to determine if the components in the river bullheads were induced. Induction of MFO components could be indicative of chemical contamination of the river water and of contaminant stress in the fish. In general, biochemical hepatic microsomal MFO component levels in bullheads from the river were the same as, or lower than, those in bullheads from uncontaminated sites. However, the liver weight as a percentage of body weight was significantly greater in bullheads from the river than in those from the uncontaminated sites. Thus, a comparison of bullheads from the river and the uncontaminated sites appeared to show that relative liver weight was indicative of chemical contamination of the river water and of contaminant stress in its fish. However, biochemical hepatic microsomal components measured in this study were apparently not adequate as indicators of chemical contamination of the river water or of contaminant stress in bullheads from the river.