2,2',4,4',5,5'- and 3,3',4,4',5,5'-Hexachlorobiphenyl pretreatments alter the biliary excretion of a challenge dose of 7,12-[ super(3)H]dimethylbenz[a]anthracene in rainbow trout (Oncorhyncus mykiss)

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 56; no. 4; pp. 642 - 649
• Main Authors: Foster, E P, Curtis, L R
• Format: Journal Article
• Language: English
• Published: 01.04.1999
• Subjects: hexachlorobiphenyl; Oncorhynchus mykiss
• DOI: 10.1139/cjfas-56-4-642
• ISSN: 0706-652X

This study compared disposition of a polycyclic aromatic hydrocarbon (PAH) in rainbow trout after di-ortho and non-ortho polychlorinated biphenyl (PCH) pretreatments. Four weeks after intraperitoneal (i.p.) injection with 50 or 250 mu g of the di-ortho 2,2',4,4',5,5'-hexachlorobiphenyl (2HxCB)/g or 5 or 25 mu g of the non-ortho 3,3',4,4',5,5'-hexachlorobiphenyl (3HxCB)/g, rainbow trout were i.p. injected with 10 nmol [ super(3)H]7,12-dimethylbenz[a]anthracene (DMBA)/g. Livers and gallbladders were removed 16 h later. Biliary excretion of [ super(3)H]DMBA decreased after i.p. injection of 2HxCB or 3HxCB. In a second experiment, rainbow trout were fed 60 or 220 ng 2HxCB/g fish/day or 1.9 or 7.8 ng 3HxCB/g fish/day for 4, 8, or 12 weeks. Fish were then i.p. injected with 10 nmol [ super(3)H]DMBA/g fish. Liver, bile, mesenteric fat, stomach, muscle, kidney, and plasma were sampled 16 h later. Fish fed 220 ng 2HxCB/g fish/day for 4 weeks and 60 or 220 ng 2HxCB/g fish/day for 8 weeks had greater biliary concentrations of [ super(3)H]DMBA than controls. Biliary [ super(3)H]DMBA increased for fish fed 7.8 ng 3HxCB/g fish/day for 4 weeks. Thus, feeding both di-ortho and non-ortho PCBs transiently stimulated [ super(3)H]DMBA biliary excretion. Growth and survival data indicated no overt toxicity of the PCB doses used here via either exposure route. High i.p. doses that inhibited biliary excretion of [ super(3)H]DMBA were probably less environmentally relevant than the dietary doses fed here.