PH01 Endocrine Disruption
Exhibit Hall
8:00 AM - Thursday, 13 November 2003
(PH011) In vivo effects of dietary atrazine on female japanese quail development.
Wilhelms, K1, 2, Johannsen, S2, Scanes, C1, 2, 1 Interdepartmental Toxicology Program, Iowa State University, Ames, Iowa, USA2 Department of Animal Science, Iowa State University, Ames, Iowa, USA
ABSTRACT- Atrazine is the most commonly used herbicide in the United States with usage at or exceeding 70 million pounds/year. Although atrazine has low acute toxicity, recently it has been reported to be a potential endocrine disruptor at very low concentrations in amphibians and at high doses in rats. These reports have stimulated research on endocrine effects of atrazine. There is little information on the effects of atrazine on birds. The present report examines the effect of atrazine in the diet of female Japanese quail that were held reproductively quiescent with minimal gonadal development by non-stimulatory photoperiods. Four-week old female Japanese quail were fed corn-soybean meal diets supplemented with 0.001, 0.1, and 10ppm atrazine (nominal concentration) for two weeks. At the high dose, birds receiving atrazine had increases (P<0.05) in oviductal weights. This is indicative of either elevated circulating concentrations of estrogens or increased estrogen receptors in the oviduct as either would result in the induction of ovarian growth. There were, however, no effects (p>0.05) on ovarian weights (indicating no change in circulating concentrations of gonadotropins) or in plasma concentrations of calcium (indicative of no change in circulating concentrations of estrogens as these would induce synthesis of the calcium binding vitellogenin). Moreover, atrazine had no effect on feed-intake, body weight (or body weight gain) or liver weight. Further studies are examining effects on plasma concentrations of steroids (17
-estradiol and testosterone), gonadotropins, and ovarian aromatase activity.
Key words: quail, atrazine, oviduct, development