PARENT SESSION

PM15 Biomarkers
Exhibit Hall
8:00 AM - Monday

(PM244) Effects of atrazine on mixed function oxygenases in Xenopus laevis.

Park, J.-W.¹, Hecker, M.¹, Murphy, M.¹, Jones, P.¹, Solomon, K.², van der Kraak, G.², Kendall, R.³, Giesy, J.¹, ¹ Michigan State University, East Lansing, Michigan, USA² University of Guelph, Guelph, Ontario, Canada³ Texas Tech University, Lubbock, Texas, USA

ABSTRACT- Adult male African clawed frogs (Xenopus laevis) were exposed to either estradiol (0.1g/L) or atrazine (10 or 100g/L) to examine potential changes on mixed function oxygenase activities. In addition, effects as a function of exposure duration (24d and 49d) were also investigated. Median activities were similar after both exposure periods with highest median activities in the controls (24d: 37 pmol/min/mg protein; 49d: 43 pmol/min/mg protein). A significant decrease (p<0.05) in median EROD activity was observed for both atrazine treatment groups (10g/L: 17.7pmol/min/mg protein; 100g/L: 17.8pmol/min/mg protein) as well as for E2 (20.8pmol/min/mg protein) exposed frogs after 49 days. Exposure for 24 d resulted into a similar response with significant reductions in EROD activities for all tested exposures except from the 100g/L treatment. These results indicate that atrazine has the potential to interact with the phase I metabolization system in X. laevis.

Key words: amphibians, atrazine, MFO, EROD