A) In vivo CYP1A enzyme activities (A) and in vivo CYP1A protein expression (B). CYP1A enzyme activities and protein expression in juvenile Atlantic cod exposed in vivo to vehicle (5 ml peanut oil/kg fish), ketoconazole (12 mg/kg fish), nonylphenol (25 mg/kg fish), ethynylestradiol (5 mg/kg fish) and ketoconazole + nonylphenol (12 + 25 mg/kg fish). A) EROD activities. B) CYP1A protein levels analyzed using PAb against rainbow trout CYP1A. Each bar represents mean values of eight to nine fish ± SD; aSignificantly different from vehicle treated fish; bSignificantly different from ketoconazole+nonylphenol treated fish; P < 0.05.