Complex metabolic interactions between benzo(a)pyrene and tributyltin in presence of dichlorodiphenyltrichloroethane in South American catfish Rhamdia quelen

• Published in: Ecotoxicology and environmental safety 2013-10, Vol.96, p.67-74
• Main Authors: Oliveira, Heloísa H.P., Babin, Mathieu, Garcia, Juan Ramon Esquivel, Filipak Neto, Francisco, Randi, Marco A.F., Oliveira Ribeiro, Ciro A., Pelletier, Émilien
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Animals; Applied ecology; BaP; Benzo(a)pyrene - analysis; Benzo(a)pyrene - metabolism; Benzo(a)pyrene - toxicity; Bile; Bile - chemistry; Biological and medical sciences; catfish; Catfishes - metabolism; DDT; DDT (pesticide); DDT - analysis; DDT - metabolism; DDT - toxicity; dibutyltin; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; exposure duration; Fish; freshwater; Fundamental and applied biological sciences. Psychology; Hepatic metabolism; liver; Liver - drug effects; Liver - metabolism; metabolism; metabolites; monobutyltin; Rhamdia quelen; toxic substances; Trialkyltin Compounds - analysis; Trialkyltin Compounds - metabolism; Trialkyltin Compounds - toxicity; Tributyltin; United States; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism; Water Pollutants, Chemical - toxicity
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2013.06.024

In an attempt to explore complex metabolic interactions between toxicants present in polluted freshwater, hepatic metabolism of benzo(a)pyrene (BaP) and tributyltin (TBT) in fish was investigated when these compounds were administrated alone, mixed together and along with dichlorodiphenyltrichloroethane (DDT). Ten Rhamdia quelen per group were treated with a single intra-peritoneal (IP) dose (5-day experiment) or three successive doses (15-day experiment) either containing BaP (0.3; 3 or 30mgkg−1) or TBT (0.03; 0.3 or 3mgkg−1) or a combination of BaP+TBT, BaP+DDT, TBT+DDT and BaP+TBT+DDT under their respective lower doses, with DDT dose kept at 0.03mgkg−1. Tetrahydroxy-benzo(a)pyrene (BaP-tetrol-I), and dibutyltin (DBT) and monobutyltin (MBT) were analyzed to assess BaP and TBT hepatic metabolism, respectively. A significant difference in BaP-tetrol-I concentration was observed in liver and bile between the lowest and the highest doses of BaP in both 5 and 15-day experiments. In the 15-day experiment, the presence of TBT with BaP reduced the amount of BaP-tetrol-I in bile compared to the BaP alone. The time of exposure and the number of doses affected BaP-tetrol-I concentration in the bile of fish exposed to BaP 0.3mgkg−1 and BaP+DDT. TBT and its metabolites concentrations showed a dose-dependent increase in the liver in both experiments and in the bile in the 5-day experiment. TBT at its lowest dose was completely metabolized into DBT and MBT in the liver in the 15-day experiment. No TBT metabolites were detected in the bile of fish exposed to the mixtures in the 5-day experiment, except for a small MBT amount found in BaP+TBT+DDT. This study strengthens the hypothesis of a metabolic interaction between BaP and TBT in fish and suggests DDT as an important third player when present in the mixture. •Hepatic metabolism of BaP and TBT in fish was investigated.•BaP and TBT metabolites were found in liver and bile.•A metabolic interaction between BaP and TBT was found.•Presence of DDT with BaP and/or TBT modified their metabolism.