PM11 Wildlife Ecotoxicology
Exhibit Hall
8:00 AM - Monday
(PM184) Estradiol and testosterone levels in juvenile and adult frogs from atrazine-exposed sites in Michigan.
Tompsett, A1, Murphy, M1, Coady, K2, Hecker, M1, Jones, P1, Giesy, J1, Smith, E3, Van Der Kraak, G4, Solomon, K4, Kendall, R3, 1 Michigan State University, East Lansing, MI, USA2 Entrix, Inc., Okemos, MI, USA3 Texas Tech University, Lubbock, TX, USA4 University of Guelph, Guelph, ON, Canada
ABSTRACT- Exposure to atrazine has been reported to cause gonadal deformities and affect plasma hormone concentrations and aromatase activities in frogs in laboratory exposures, but little is known about possible effects on wild frog populations. Adult and juvenile green frogs (Rana clamitans), American bullfrogs (Rana catesbeiana) and northern leopard frogs (Rana pipiens) were collected throughout the summers of 2002 and 2003 from fifteen field sites in central Michigan, representing a range of atrazine exposure concentrations. Atrazine concentrations were greatest in early to mid-summer, ranging from <0.22 to >250 
g/L across all sites. Steroid concentrations were measured in plasma via ether extraction and hormone ELISA. Reference site (atrazine concentration <0.22 g/L) mean plasma testosterone concentrations ranged from 150 to >4,800 pg/mL in adult females, and from 338 to >4,900 pg/mL in adult males. Mean testosterone concentrations at exposed sites ranged from 255 to >4,400 pg/mL in adult females and from 396 to >4,500 pg/mL in adult males. Mean estradiol concentrations at reference sites ranged from 136 to >6,700 pg/mL in adult females and from 917 to >5,800 pg/mL in adult males. Mean plasma estradiol concentrations at exposed sites ranged from 130 to >15,000 pg/mL in adult females and from 56 to >15,000 pg/mL in adult males. Estradiol concentrations in juveniles ranged from undetectable to >198 pg/mL. Testosterone concentrations in juveniles ranged from undetectable to >27 pg/mL. Comparisons were made between collection sites to determine whether atrazine water concentrations were correlated with the measured parameters.
Key words: atrazine, frog, testosterone, estradiol