4种典型溴代阻燃剂对离体条件下罗非鱼肝脏抗氧化系统影响的研究

以罗非鱼(Mossambica tilapia)为实验生物,研究了离体条件下其肝脏抗氧化系统中谷胱甘肽(GSH)含量、谷胱甘肽硫转移酶(GST)和超氧化物歧化酶(SOD)活性对4种溴代阻燃剂(Brominated flame retardants,BFRs)——四溴联苯醚(BDE-47)、十溴联苯醚(BDE-209)、六溴环十二烷(HBCD)和四溴双酚A(TBBPA)的响应.研究结果表明:离体暴露于4种BFRs 1 h后,罗非鱼肝脏上清液中GSH含量和SOD活性随暴露剂量升高均呈现先升高后回落的趋势,但总体均高于对照组水平;GST活性则被抑制.上述3种抗氧化参数中,同一参数对4种BFRs响应均呈现一致的变化趋势,其中GST和SOD活性响应更为灵敏.GST活性对BDE-47、BDE-209和HBCD的最低响应浓度均低于1 ng·L-1,且与TBBPA和BDE-209在一定浓度范围内存在较好的剂量-效应关系;SOD活性对4种BFRs暴露较为敏感,最低响应浓度均低于10 ng·L-1,并且与除BDE-209外的上述3种污染物在一定的浓度范围内具有良好的剂量-效应关系.因此,GST和SOD活性指标是值得进一步研究的溴代阻燃剂污染候选生物标志物.

Effects of four typical brominated flame retardants on hepatic antioxidant system of Mossambica tilapia in vitro

The present work aims to investigate the responses of glutathione (GSH), glutathione S-transferase (GST) and superoxide dismutase (SOD) in Mossambica tilapia liver supernatant exposed in vitro to four kinds of brominated flame retardants (BFRs) (BDE-47, BDE-209, HBCD and TBBPA) for 1 h at different doses. The results showed that hepatic GSH content and SOD activity increased at lower concentrations, and then decreased at higher concentrations, while GSH content and SOD activity in the exposed groups were higher than that in the control at all mentioned concentrations. The GST activity was inhibited by the four types of BFRs. The results indicated that the same antioxidant parameter had the similar response trend to the 4 BFRs. Moreover, the responses of the activity of GST and SOD to the BFRs were more sensitive than that of GSH content. The lowest observed effect concentration (LOEC) of GST activity to BDE-47, BDE-209 and HBCD was less than 1 ng·L^-1 and GST activity values had a good linear relationship with the certain concentrations of TBBPA and BDE-209. The SOD activity was sensitive to all four types of BFRs and the LOEC was less than 10 ng·L^-1. The values of SOD activity had a good linear relationship with the certain concentrations of BDE-47, HBCD and TBBPA. Our results suggested that the parameters of GST and SOD in Mossambica tilapia liver antioxidant system had the potential to serve as biomarkers to evaluate the adverse effects of BFRs pollution.