不同温度下恩诺沙星及其代谢物在斑点叉尾鲖各组织中的残留及消除规律比较

分别在18℃和28℃水温下, 以20 mg/(kg·d)鱼体质量对斑点叉尾鲙给药恩诺沙星, 连续灌胃7d。给药后在不同的时间点取样, 用高效液相色谱荧光检测器检测, 研究恩诺沙星及其主要代谢产物环丙沙星在斑点叉尾鲙体内(血液、肌肉、皮肤、肝脏和肾脏)的残留消除规律。结果表明, 恩诺沙星在不同组织、不同水温消除速率不同: 水温为18℃, 皮肤、肝脏、肾脏和肌肉中的消除曲线方程分别为C=1022.1e–0.034t、C=2601.3e–0.046t、C=2903.6e–0.072t和C=1186.5e–0.036t, 消除半衰期分别为31.79d、45.29d、16.15d和35.54d; 水温为28℃, 皮肤、肝脏、肾脏和肌肉中的消除曲线方程分别为C=8805.5e–0.04t、C=3154e–0.08t、C=4145.1e–0.1t和C=1302.1e–0.068t, 消除半衰期分别为18.33d、6.26d、12.44d和10.34d。恩诺沙星在斑点叉尾鲙体内可代谢为环丙沙星, 恩诺沙星在斑点叉尾鲙体内的代谢速度较慢, 代谢物环丙沙星在斑点叉尾鲙体内的消除速度比恩诺沙星快; 在18℃水温下, 斑点叉尾鲙肉中的恩诺沙星和环丙沙星完全消除需要150d以上; 在28℃水温下, 斑点叉尾鲙肉中的恩诺沙星和环丙沙星完全消除需要120d。在实验条件下, 建议水温为18℃和28℃时, 休药期分别为3240℃·日和4200℃·日。

STUDIES ON ELIMINATION DYNAMICS OF ENROFLOXACIN RESIDUES AND ITS METABOLITES IN CHANNEL CATFISH AT TWO DIFFERENT WATER TEMPERATURES

At water temperature of 18℃ and 28℃, channel catfish was administered orally with enrofloxacin (EF) in dose of 20 mg/kg for 7 days, the time courses of concentrations of enrofloxacin and ciprofloxacin in fish tissues (plasma, muscle, skin, liver and kidney) were measured with high-performance liquid chromatography and a fluores-cence detector. The results indicated that elimination of enrofloxacin was different in skin, liver, kidney and muscle at 18℃ and 28℃: the equations of elimination curve of enrofloxacin in skin, liver, kidney and muscle were C=1022.1e–0.034t,C=2601.3e–0.046t,C=2903.6e–0.072t andC=1186.5e–0.036t, the elimination half-lives were 31.79d, 45.29d, 16.15d and 35.54d at 18℃, respectively; the equations of elimination curve of enrofloxacin wereC=8805.5e–0.04t, C=3154e–0.08t,C=4145.1e–0.1t andC=1302.1e–0.068t, the elimination half-lives were 18.33d, 6.26d, 12.44d and 10.34d at 28℃, respectively. Enrofloxacin was changed into ciprofloxacin, the metabolism and elimination of enrofloxacin in channel catfish was relatively slower; enrofloxacin and ciprofloxacin in the channel catfish tissues could not be found after 150 days at 18℃, and 120 days at 28℃. The predicted withdrawal time was 3240℃·d and 4200℃·d respectively.