| This study was designed to examine the potential influence in vivo of BaP, TBT and their mixture on splenic and renal antioxidant defense system of Sebastiscus marmoratus. In experimental condition, Sebastiscus marmoratus were exposed through water to BaP (10, 100, 1000 ng/L), TBT (1, 10 ,100 ng/L) and their mixture (5 ng/L BaP + 0.5 ng/L TBT, 50 ng/L BaP + 5 ng/L TBT, 500 ng/L BaP + 50 ng/L TBT ); Spleens and kidneys were collected for biochemical analysis after exposure for 7, 25, 50 days and after transferred to recovery tanks for 7, 20 days. The results showed:1. BaP, TBT and their mixture influenced antioxidant defense system of spleen in Sebastiscus marmoratus. Cotreatment with BaP and TBT for 7 days potentiated the induction of GPx activity by BaP or TBT alone. The cotreatment for 25 and 50 days resulted in inhibition of GPx activity, which was similar to the effect of TBT. Exposed to BaP for 7 and 25 days, GST activities were significantly elevated and then no alteration with prolonged exposure. Cotreatment with BaP and TBT principally inhibited the GST activity, which was similar to the effect of TBT. Cotreament with BaP and TBT for 25 or 50 days potentiated the depletion of GSH by BaP or TBT alone. Exposed to BaP or/and TBT, no significant alterations of MDA levels were observed compared with the matched control. Short-term exposure of environmentally relevant concentrations of BaP or TBT could result in induction of antioxidant defense system. A significant decrease of these indexes, such as GSH, GST, GPx appear to imply more severe contamination.2 BaP, TBT and their mixture influenced antioxidant defense system on kidney in Sebastiscus marmoratus. Exposed to BaP or/and TBT, no significant alterations of GST levels were observed compared to the control. Cotreatment with TBT alone for 7 days, MDA contents were significantly elevated and then no alteration compared to the control with prolonged exposure. Exposed to TBT for 7 days, GPx activities were significantly elevated and recovered to the levels corresponding to that of the control, after transferred to dean recovery tanks. Cotreatment with BaP and TBT significantly elevated the GPx activity, which was similar to the effect of TBT. After exposure to the mixture for 7 days, the induction of GPx activity influenced by TBT was antagonized by BaP. Exposure to 1 ng/L TBT for 7 days significantly decreased the GSH content compared to the control. Exposure to BaP alone for 7 days elevated the CAT activity, which was similar to the effect of the mixture.Therefore, the antioxidant defense system of kidney and spleen in Sebastiscus marmoratus was sensitive to the exposure of BaP and TBT at environmental levels. There was an effective mechanism in kidney and spleen to keep itself from oxidative damage. There is an interaction between BaP and TBT on antioxidant defense system of kidney and spleen in Sebastiscus marmoratus. When take the antioxidant defense system of kidney and spleen as a biomarker to monitor the pollution of BaP or TBT, the interaction and the effect of other comtaminants should not be ignored. |
