PH03 Perchlorate
Exhibit Hall
8:00 AM - Thursday, 13 November 2003
(PH052) Eco-relevant perchlorate concentrations do not alter thyroid function in adult clawed frogs.
Goleman, W.1, Gentles, B.1, Hu, F.1, Wages, M.1, Carr, J.1, 1 Texas Tech University, Lubbock, TX, USA
ABSTRACT- To investigate ammonium perchlorate (AP) effects on adult anurans, we exposed sexually mature female Xenopus laevis to environmentally-relevant concentrations of AP (38 or 14040 ppb) for 10 wk and examined various aspects of thyroid and reproductive function. Initial histological examination of serially-sectioned thyroid glands revealed no evidence of treatment-related thyroid follicular cell hypertrophy or colloid depletion in AP-treated frogs. To confirm these results, thyroid gland cross-sectional area and follicle lumen area were determined quantitatively. No significant between-treatments differences were observed, although there was a trend toward reduced lumen area with increasing AP concentration. We observed no measurable effect of AP on the gonadosomatic index, ovulated clutch size, or plasma estradiol concentrations. Our data suggest that a 10 wk exposure to environmentally-relevant concentrations of AP does not significantly affect thyroid function or reproductive status in adult female X. laevis. (Supported in part by the U.S. Department of Defense, through SERDP under a Cooperative Agreement with the USAF, Inst. for Environ, Safety, and Occup. Health, Brooks AFB, TX).
Key words: Xenopus laevis, Amphibian, Reproduction, Estradiol