title: Effects of inducers of cytochrome P450s on enrofloxacin N-deethylation in crucian carp Carassius auratus gibelio.
abstract: In this study with crucian carp (Carassius auratus gibelio), the effect on enrofloxacin (EF) and its metabolite ciprofloxacin (CF) and on the activity of cytochrome P450 1A (CYP1A) and cytochrome P450 3A (CYP3A) was estimated following the oral administration of rifampicin (RIF) (12mg/kg) and β-naphthoflavone (BNF) (12mg/kg), respectively. First, reversed-phase high-performance liquid chromatography (RP-HPLC) was used to detect the pharmacokinetics of EF with continual blood sampling. In RIF-treated, BNF-treated and control groups, the value of the CmaxCF/CmaxEF ratio was 4.41, 0.81 and 0.95, and the corresponding value of the AUC0-t-CF/AUC0-t-EF ratio was 3.69, 1.84 and 1.76, respectively. In the RIF-treated, BNF-treated and control groups, the MRT values of EF were 26.57, 27.45 and 30.88h, and the corresponding values for CF were 5.79, 35.18 and 38.11h, respectively. Based on these results for crucian carp, the accumulation and elimination of EF and CF in the RIF-treated group were more rapid than in BNF-treated and control groups. Second, liver microsomes were pretreated with the inducer of CYP1A for BNF and that of CYP3A for RIF, and then the enzymatic activities of CYP1A and CYP3A were measured, respectively. The activities of ethoxyresorufin-O-deethylation (EROD) and erythromycin-N-demethylation (ERND) increased significantly (P<0.05) for CYP1A and CYP3A, respectively. However, in further experiments on the formation of CF, the level of EF N-deethylation was significantly induced by RIF and inhibited by ketoconazole (KTZ) for CYP3A but had no influence for CYP1A, BNF and berberine chloride (BER). We concluded that CYP3A might be responsible for the N-deethylation of EF and because of this activity, could also serve as a toxicity biomarker in crucian carp.
authors.affiliation: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, 300 Jungong Road, Shanghai, 200090, China.
authors.forename: Guihong
authors.initials: G
authors.lastname: Fu
authors.affiliation: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, 300 Jungong Road, Shanghai, 200090, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Zhou
authors.affiliation: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, 300 Jungong Road, Shanghai, 200090, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, 300 Jungong Road, Shanghai, 200090, China. Electronic address: fwenhong@163.com.
authors.forename: Wenhong
authors.initials: W
authors.lastname: Fang
authors.affiliation: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, 300 Jungong Road, Shanghai, 200090, China.
authors.forename: Junfang
authors.initials: J
authors.lastname: Zhou
authors.affiliation: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, 300 Jungong Road, Shanghai, 200090, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhao
authors.affiliation: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, 300 Jungong Road, Shanghai, 200090, China.
authors.forename: Licai
authors.initials: L
authors.lastname: Ma
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000097:blood / Q000493:pharmacokinetics*; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism; D065693:Cytochrome P-450 Enzyme Inducers / Q000494:pharmacology*; D004347:Drug Interactions; D000077422:Enrofloxacin; D024841:Fluoroquinolones / Q000097:blood / Q000493:pharmacokinetics*; D006054:Goldfish / Q000097:blood / Q000378:metabolism*; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D012293:Rifampin / Q000494:pharmacology; D019324:beta-Naphthoflavone / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D065693:Cytochrome P-450 Enzyme Inducers; D024841:Fluoroquinolones; D000077422:Enrofloxacin; D019324:beta-Naphthoflavone; D019363:Cytochrome P-450 CYP1A1; D051544:Cytochrome P-450 CYP3A; D012293:Rifampin
keywords: Ciprofloxacin; Cytochrome P450s; Enrofloxacin; N-Deethylation