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Polychlorinated biphenyls and biotransformation enzymes in three species of sea turtles from the Baja California peninsula of Mexico.

Richardson KL, Lopez Castro M, Gardner SC, Schlenk D - Arch. Environ. Contam. Toxicol. (2009)

Bottom Line: There were no significant differences in GST activities between species.Grouping congeners based on structure-activity relationships for CYP isoenzymes suggested limited activity of CYP1A contribution to PCB biotransformation in sea turtles.These results suggest potential accumulation of PCBs that are CYP1A substrates and provide evidence for biotransformation capacity, which differs from known animal models, highlighting the need for further studies in reptiles, particularly those threatened with extinction.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Sciences, University of California, Riverside, Riverside, CA 92521, USA.

ABSTRACT
Concentrations of polychlorinated biphenyls (PCBs) as well as the expression patterns of cytochrome P450 (CYP) enzymes and glutathione-S-transferase (GST) activities were measured in livers of loggerhead (Caretta caretta), green (Chelonia mydas), and olive ridley (Lepidocheyls olivacea) sea turtles from the Baja California peninsula of Mexico. The mean concentrations of total PCBs were 18.1, 10.5, and 15.2 ng/g wet weight (ww) respectively for the three species and PCB 153 was the dominant congener in all samples. Total PCB concentrations were dominated by penta- and hexa-chlorinated biphenyls. The mean estimated TEQs were 42.8, 22.9, and 10.4 pg/g (ww) for loggerhead, green, and olive ridley, respectively, and more than 70% was accounted for by non-ortho PCBs. Western blots revealed the presence of hepatic microsomal proteins that cross-reacted with anti-CYP2K1 and anti-CYP3A27 antibodies but not with anti-CYP1A antibody. There were no significant differences in GST activities between species. Grouping congeners based on structure-activity relationships for CYP isoenzymes suggested limited activity of CYP1A contribution to PCB biotransformation in sea turtles. These results suggest potential accumulation of PCBs that are CYP1A substrates and provide evidence for biotransformation capacity, which differs from known animal models, highlighting the need for further studies in reptiles, particularly those threatened with extinction.

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A map of the Baja California peninsula. Stars indicate sampling locations
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Fig1: A map of the Baja California peninsula. Stars indicate sampling locations

Mentions: Between 2001 and 2003, samples of liver tissue were collected from stranded wild-born loggerhead, green, and olive ridley turtles from the waters surrounding the Mexican states of BC and Baja California Sur (see Fig. 1). Tissue samples were obtained as a result of natural mortality, incidental fisheries, or unknown causes of death and were only collected from animals for which time of death could be approximated within 24 h. Turtles were necropsied and a sample of liver tissue was placed in aluminum foil and stored on ice for transport and then stored at −80°C until analysis. Table 1 provides specific features of the sampled individuals.Fig. 1


Polychlorinated biphenyls and biotransformation enzymes in three species of sea turtles from the Baja California peninsula of Mexico.

Richardson KL, Lopez Castro M, Gardner SC, Schlenk D - Arch. Environ. Contam. Toxicol. (2009)

A map of the Baja California peninsula. Stars indicate sampling locations
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2807021&req=5

Fig1: A map of the Baja California peninsula. Stars indicate sampling locations
Mentions: Between 2001 and 2003, samples of liver tissue were collected from stranded wild-born loggerhead, green, and olive ridley turtles from the waters surrounding the Mexican states of BC and Baja California Sur (see Fig. 1). Tissue samples were obtained as a result of natural mortality, incidental fisheries, or unknown causes of death and were only collected from animals for which time of death could be approximated within 24 h. Turtles were necropsied and a sample of liver tissue was placed in aluminum foil and stored on ice for transport and then stored at −80°C until analysis. Table 1 provides specific features of the sampled individuals.Fig. 1

Bottom Line: There were no significant differences in GST activities between species.Grouping congeners based on structure-activity relationships for CYP isoenzymes suggested limited activity of CYP1A contribution to PCB biotransformation in sea turtles.These results suggest potential accumulation of PCBs that are CYP1A substrates and provide evidence for biotransformation capacity, which differs from known animal models, highlighting the need for further studies in reptiles, particularly those threatened with extinction.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Sciences, University of California, Riverside, Riverside, CA 92521, USA.

ABSTRACT
Concentrations of polychlorinated biphenyls (PCBs) as well as the expression patterns of cytochrome P450 (CYP) enzymes and glutathione-S-transferase (GST) activities were measured in livers of loggerhead (Caretta caretta), green (Chelonia mydas), and olive ridley (Lepidocheyls olivacea) sea turtles from the Baja California peninsula of Mexico. The mean concentrations of total PCBs were 18.1, 10.5, and 15.2 ng/g wet weight (ww) respectively for the three species and PCB 153 was the dominant congener in all samples. Total PCB concentrations were dominated by penta- and hexa-chlorinated biphenyls. The mean estimated TEQs were 42.8, 22.9, and 10.4 pg/g (ww) for loggerhead, green, and olive ridley, respectively, and more than 70% was accounted for by non-ortho PCBs. Western blots revealed the presence of hepatic microsomal proteins that cross-reacted with anti-CYP2K1 and anti-CYP3A27 antibodies but not with anti-CYP1A antibody. There were no significant differences in GST activities between species. Grouping congeners based on structure-activity relationships for CYP isoenzymes suggested limited activity of CYP1A contribution to PCB biotransformation in sea turtles. These results suggest potential accumulation of PCBs that are CYP1A substrates and provide evidence for biotransformation capacity, which differs from known animal models, highlighting the need for further studies in reptiles, particularly those threatened with extinction.

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