Abstract
Introduction : Reptile populations all around the world are decreasing. The dominant stressors are decrease of habitats, targeted harvesting and climate change. Environmental pollution could be a common factor weakening populations, yet we know little about the effect of xenobiotics on reptiles. Pyrene, as a representative of polycyclic aromatic hydrocarbons (PAHs), was choosen to study the metabolism in freshwater turtles, as disasters involving PAHs (oil spills) are one of the main causes of health and reproductive problems in water-living organism.
Materials and Methods:Red-eared sliders (Trachemys scripta elegans), Chinese pond turtles (Mauremys reevesii) and Chinese softshell turtles (Pelodiscus sinensis) were used. Pyrene exposure occurred thorugh oral feeding (4 mg/kg pyrene, dissolved in corn oil) or through water (250 μg/l). Exposed water was filtered, passed through a solid-phase cartridge, and eluded with methanol. Metabolites were determined by HPLC with FD equipped with an ODS column, and identified by an MS/MS system. Liver subcellular fractions were isolated from fresh samples, protein concentration were measured by BCA protein assay. EROD, UGT and SULT activity were measured.
Results and Discussion:Distinct metabolite distributions were measured for each species. The dominant metabolite in all three species was pyrene-1-sulfate. All enzyme activities were low compared to mammals (rat). Sulfate conjugation was the dominant phase II metabolic pathway in all three species.
