Juvenile rainbow trout (Oncorhynchus mykiss) were fed either 5 or 20 μg 2,2′,4,4′,5,5′‐hexachlorobiphenyl (245‐HxCB)/g diet (wet wt.) for 4, 8, or 12 weeks. Hepatic xenobiotic‐metabolizing enzyme activities and dietary 245‐HxCB accumulation in liver, muscle, and remaining carcass were determined. Liver‐to‐body weight ratios were not altered by either of the two 245‐HxCB concentrations. Relative growth rate increased with time but was not altered by 245‐HxCB concentration. Bioaccumulation of 245‐HxCB was dose and time dependent in all tissues without reaching apparent steady state. Hepatic arylhydrocarbon hydroxylase (AHH) activities increased with 245‐HxCB dose and with time. Ethoxyresorufin‐O‐deethylase (EROD) activities also increased in fish fed 20 μg 245‐HxCB/g diet. No 245‐HxCB‐induced changes in uridine diphosphoglucuronosyl transferase (UDP‐GT) or NADPH‐cytochrome‐c reductase (NCCR) activities were determined. High‐resolution GC‐MS analysis of the 245‐HxCB standard revealed trace (0.4‐0.5%) contamination by two mono‐ortho pentachlorobiphenyls (PnCBs): 2,3,3′,4,4′‐PnCB and 2,3,4,4′,5‐PnCB. Total liver accumulation of these contaminants was inversely related with corresponding EROD and AHH activities and estimated to contribute minimally to their induction. Results from this study suggested that long‐term dietary 245‐HxCB exposures induced cytochrome P4501A activities in rainbow trout liver.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-14565 |
| Date | 01 January 1995 |
| Creators | da Costa, Emmanuel G., Curtis, Lawrence R. |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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