诺氟沙星对中国明对虾鳃和血清ECOD、APND和GST活性的影响

诺氟沙星药饵每天2次投喂中国明对虾(Fenneropenaeus chinensis),给药剂量分别为0 mg/kg(对照组)、15mg/kg(LD组)、30 mg/kg(MD组)和60 mg/kg(HD组),连续投喂7 d后,分析诺氟沙星对中国明对虾鳃和血清7-乙氧基香豆素-O-脱乙基酶(ECOD)、氨基比林-N-脱甲基酶(APND)和谷胱甘肽-S-转移酶(GST)活性的影响。结果表明,不同浓度诺氟沙星对中国明对虾鳃和血清GST活性呈现显著抑制作用(P<0.05),且GST活性随着取样时间推移表现出先下降后上升的趋势。其中MD组鳃GST活性在4 h时达到最低,是对照组的8.87%;LD组血清GST活性在24 h达到最低值12.01 U/mL,仅为对照组的25.02%。与对照组相比较,给药组中国明对虾鳃和血清APND和ECOD活性均受到显著抑制(P<0.05),且呈现出一定的时间和剂量效应,随着浓度升高,APND和ECOD活性逐渐降低;而随着时间推移,APND和ECOD活性呈现先下降后上升的趋势。本研究通过探讨诺氟沙星对上述酶类的影响,为诺氟沙星的合理使用及与其他药物的联用提供理论参考。

Effects of norfloxacin on gill and serum ECOD, APND, and GST activity in Fenneropenaeus chinensis

Chinese shrimp,Fenneropenaeus chinensis,were fed 0 mg/kg(control,CK),15 mg/kg(low dose,LD),30 mg/kg(mid dose,MD) and 60 mg/kg(high dose,HD) norfloxacin(NFLX) for 7 d.We then measured the change in gill and serum ethoxycoumarin-O-deethylase(ECOD),aminopyrine N-demethylase(APND),and glu-tathione-S-transferases(GST) activity at 2,4,6,8,10,12,24,or 48 h after the last oral administration.The shrimp[(5.8±0.4 g)] were held in 200 L plastic tanks(n=20 shrimp/tank) at salinity of 25.1±0.7,(22.0±1.0)°C and pH 8.1±0.6.At each time point we randomly selected eight shrimp from each replicate.The shrimp were immediately frozen in liquid nitrogen and stored at ?70℃ until analysis.Gill and serum GST activity was inhibited by NFLX.GST activity was 12.01 U/mL after 4 h in the gill of the MD group and was only 8.87% the level in the CK group.Serum GST activity was 3.99-fold higher in the CK group than in the LD group after 24 h(P<0.05).APND and ECOD decreased initially then increased and activity was significantly lower in all treatment groups at all times relative to the controls.Higher concentrations of NFLX were associated with increased inhibition of APND and ECOD.