池塘养殖条件下恩诺沙星及其代谢产物在斑点叉尾鮰体内的残留消除规律
Residues elimination rules of enrofloxacin and its metabolites in channel catfish (Ietalurus punetaus) under pond culture conditions

在池塘养殖条件下，每天以20 mg/kg和40 mg/kg剂量的恩诺沙星药饵投喂斑点叉尾鮰，周期为5 d，研究恩诺沙星及其代谢产物在斑点叉尾鮰体内的分布与残留消除规律。分析结果显示，低剂量组和高剂量组斑点叉尾鮰肝脏中恩诺沙星的达峰时间分别在给药期间第3天和第4天，达峰时的药物含量分别为12.24、15.97 mg/kg。低剂量组肝脏、肌肉和血液中的消除曲线方程分别为C=0.25e-0.136t、 C=0.31e-0.082t和C=0.23e-1.37t，消除半衰期分别为5.10、8.43和5.06 d。高剂量组肝脏、肌肉和血液中的消除曲线方程分别为C=0.70e-0.173t、C=0.50e-0.096t和C=1.08e-0.182t，消除半衰期分别为4.00、7.22和3.81 d。恩诺沙星在斑点叉尾鮰体内可代谢为环丙沙星。在用药138 d时，低剂量组鱼体肌肉中恩诺沙星含量为0.013 mg/kg；高剂量组为0.019 mg/kg。药物在斑点叉尾鮰各组织中的消除顺序依次为血液>肝脏>肌肉。
The depletion rules of enrofloxacin and its metabolite residues were studied in channel catfish (Ietalurus punetaus) feeding with 20 mg/kg and 40 mg/kg enrofloxacin for 5 d under pond conditions. The results showed that the peaking time (tmax) of enrofloxacin in the liver was 3 d at low dose, and 4 d at high dose during the period of treatment, and the corresponding maximal drug concentration (Cmax) was 12.24 mg/kg and 15.97 mg/kg, respectively. The equations of elimination curve of enrofloxacin in the liver, muscle and blood were C=0.25e-0.136t, C=0.31e-0.082t and C=0.23e-1.37t, and the elimination half lives were 5.10 d, 8.43 d and 5.06 d at dose of 30 mg/kg, respectively. The equations of elimination curve of the drug were C=0.70e-0.173t, C=0.50e-0.096t and C=1.08e-0.182t, and the elimination half lives were 4.00 d, 7.22 d and 3.81 d at dose of 60 mg/kg, respectively. Enrofloxacin was changed into ciprofloxacin in channel catfish. The concentration of enrofloxacin in the muscle was 0.013 mg/kg after 138 d at low dose, and 0.019 mg/kg after 138 d at high dose. The elimination rate of the drug in various tissues was in the order of blood, liver and muscle.