Energetic costs of toxicant metabolism in rainbow trout ( Oncorhynchus mykiss)

Abstract

Aquatic ecosystems are continuously exposed to a variety of environmental toxicants including polychlorinated biphenyls (PCBs). A portion of the energy assimilated by the fish is dedicated to detoxification. This study investigates the changes in energetic demands associated with increased detoxification. Two CYP1A inducers were employed, PCB-126 and BNF. Resveratrol, a documented inhibitor of CYP1A activity and gene expression, was used to correlate metabolic changes in CYP1A induction with any metabolic changes. PCB-126 and BNF effectively induced CYP1A activity in vitro and in vivo. Energy metabolism was measured as changes in oxygen consumption rates and changes in plasma glucose and triglyceride concentrations as well as liver glycogen. PCB-126 and BNF treatments resulted in significant changes in metabolic parameters. Treatments with RVT were inconclusive. Although results from this study imply possible energetic changes associated with exposure, further investigation is required to obtain more conclusive results on energetic costs of exposure and detoxification.