In vivo CYP3A enzyme activities (A) and in vivo CYP3A protein expression (B). CYP3A 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) BFCOD activities. B) CYP3A protein levels analyzed using PAb against rainbow trout CYP3A. 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.