恩诺沙星对凡纳滨对虾(Litopenaeus vannamei) CYP2基因表达及氨基比林-N-脱甲基酶活性的影响

Effects of Enrofloxacin on the Expression Analysis of CYP2 and Activity of APND in Litopenaeus vannamei

中文关键词: 凡纳滨对虾  CYP2  组织分布  恩诺沙星  APND活性

英文关键词: Litopenaeus vannamei  CYP2  Tissue distribution  Enrofloxacin  Enzyme activity of APND

中文摘要:

      以凡纳滨对虾(Litopenaeus vannamei)为研究对象，运用RT-PCR方法测定CYP2基因在凡纳滨对虾组织中的表达分布，并分析不同剂量恩诺沙星对凡纳滨对虾肝胰腺中CYP2基因表达和氨基比林-N-脱甲基酶(APND)活性的影响。结果显示，CYP2在肝胰腺、鳃、血淋巴、肌肉、甲壳、肠、胃、心脏和眼柄中均有分布，在肝胰腺中表达量最高，胃次之，血淋巴中表达量最低。口服低(15 mg/kg)、中(30 mg/kg)、高(60 mg/kg) 3个剂量恩诺沙星药饵后，凡纳滨对虾肝胰腺中CYP2基因表达和APND活性较对照组均呈现下降趋势；药物浓度越高，基因表达量和酶活性越低，表明恩诺沙星可抑制CYP2在凡纳滨对虾体内的表达。在生产实践中联合用药时，应考虑到因恩诺沙星对CYP2的抑制作用而导致经其代谢的药物在生物体内的蓄积和毒性增强。

英文摘要:

      The cytochrome P450 is an important group of multi-functional oxidases engaged in the metabolism of exogenous substances. In this study we investigated the effects of enrofloxacin on the expression of CYP2 and activity of APND enzyme in hepatopancreas of Litopenaeus vannamei. Real-time PCR analysis revealed that CYP2 in L. vannamei was expressed in all tested tissues, including hepatopancreas, gills, hemolymph, muscle, carapace, intestine, stomach, heart and eyestalk. The expression level was the highest in hepatopancreas, and the lowest in hemolymph. After oral administration of enrofloxacin at different concentrations including 15 mg/kg (low-dose group), 30 mg/kg (middle-dose group), and 60 mg/kg (high-dose group), the level of CYP2 transcript in hepatopancreas decreased significantly (P<0.05) especially at 9 h (P<0.01), however exceptions occurred at 1 h, 24 h, and 96 h. The activity of APND that indicated the activity of CYP2 was measured with ELIASA. The result showed that the activity of APND was lower in the experimental groups than in the control group. APND activity in the high-dose group was lower than that in the low-dose group. All three experimental groups, especially the high-dose group (P<0.01), showed a significant decrease in APND activity (P<0.05) after 9 h, but an exception occurred at 3 h. The enzyme activity in all experimental groups was reduced (P<0.01) and reached the minimum level at 12 h. Changes in both the enzyme activity and the expression level displayed the same pattern. These results indicated that the expression of CYP2 could be impacted by enrofloxacin. Therefore, when administrating drugs in combination, the cumulative effects should be carefully evaluated.