First investigation on CYP450 1A1 and CYP450 2B induction in fibroblast cell cultures of striped dolphin (Stenella coeruleoalba) experimentally treated with polybrominated diphenyl ethers (PBDEs)

Polybrominated diphenyl ethers (PBDEs) are a major family of brominated flame retardants, being lipophilic, persistent, and toxic to fauna and humans. Today there is growing concern about accumulation of brominated organic compounds in the food chain. The highest levels of PBDEs have been found in top marine predators. In this study we use immunofluorescence techniques in fibroblast cell cultures to explore the susceptibility of cetaceans to PBDEs, with qualitative and quantitative evaluation of target proteins such as CYP450 1A1-1A2 and CYP450 2B4. Fibroblast cell cultures (third generation) from two male and two female striped dolphins (Stenella coeruleoalba) and a speciment of bottlenose dolphin (Tursiops truncatus) , sampled with biopsy darts in summer 2004 in the Mediterranean Whale Santuary, were treated experimentally with a commercial mixture (BDE-MXE, Wellington, Canada) containing 27 PBDEs, from mono- to deca-brominated. The cells were treated with the mixture solubilized in nonane (0.01 µg/ml) at three different doses were used: 0.1 µg/ml, 0.05 µg/ml and 0.01 µg/ml, for 48 h, and with nonane (0.01 µg/ml) as control. After a first reaction with the primary antibodies for CYP450 1A1-1A2 and 2B4, the cells were treated with the respective secondary antibodies marked with a fluorochrome. The main results of this experiments were: 1) the detection of presence of the cytochromes 1A1-1A2 and 2B4 in striped dolphin fibroblast cells, revealed from the crossreaction of the antibody used and from the presence of fluorescence in the fibroblasts; 2) the increase of fluorescence in relation to the treatment doses of contaminants; 3) the preliminary detection of differences in the induction phenomena between specimens and gender.