PM10 Mechanisms of Toxic Action
Exhibit Hall
8:00 AM - Monday
(PM156) Temperature effects on pharmacokinetics of PAH.
Dungavell, J1, Hodson, P1, 1 Queen's University School of Environmental Studies, Kingston, ON, Canada
ABSTRACT- The importance of environmental variables such as temperature in ecological risk assessments (ERAs) and biomonitoring projects is well known. Alterations in the rates of uptake and excretion of polycyclic aromatic hydrocarbons (PAHs) by fish can change their toxicities. Thus, an examination of the effect of temperature on the pharmacokinetics of PAH will address how temperature influences fish exposure to PAH and ultimately the risk posed by PAH. Rainbow trout (Oncorhynchus mykiss) were exposed to retene (7-isopropyl-1-methylphenanthrene) in the lab to determine the effects of temperature on rates of uptake and excretion. A partition control delivery (PCD) system was constructed to create constant and consistent retene exposure. Indices of exposure included liver CYP1A activity measured by ethoxyresorufin-O-deethylase (EROD) activity, Western blots for CYP1A protein, and concentrations of retene and its metabolite in water, tissue, and bile. The results of work on retene solubility indicate that exposure may be altered by temperature and thus affect in vivo results. When fish were exposed to retene at acclimation temperature, little difference was observed in the kinetics of PAH metabolism among different temperatures. However, fish exposed to acute temperature change showed more pronounced differences in uptake and excretion rates. Future work will include an in vitro examination of the effects of temperature on CYP1A catalytic activity by assessing substrate conversion rates with CYP1A protein isolated from control and retene-induced fish.
Key words: pharmacokinetics, temperature, retene, fish