T6 PM Immune and Endocrine Disruption: Detection and Implication
Tuesday, 15 November 2005: 1:50 PM - 5:30 PM in 324-326

(MCN-1117-737178) Effects of perfluorooctane sulfonate (PFOS) on thyroid function in quail.

McNabb, F.M.A.¹, Smith, L. ¹, Clark, K.¹, ¹ Virginia Tech, Blacksburg, VA, USA

ABSTRACT- PFOS, an environmentally stable organic fluorochemical compound used in commercial and industrial applications for its surfactant properties, is a widespread contaminant in humans and wildlife. PFOS decreases circulating thyroid hormones (THs) in laboratory rats but its mechanism(s) of action are not understood and its effects on other wildlife species have not been investigated. Our study investigated how PFOS affected thyroid function in bobwhite and Japanese quail. Adult quail were dosed orally with 5 mg/kg body weight PFOS in 0.5% Tween-20 vehicle and sampled at 7 days (bobwhite quail) or at 7 and 14 days (Japanese quail). At these sampling times in both species, plasma thyroid hormones (both T4 and T3) were decreased indicating organismal level hypothyroidism. Body weights tended to be decreased and relative thyroid weights tended to be increased, the latter effect suggesting some hypothalamic-pituitary-thyroid axis response to decreased circulating THs. Surprisingly thyroid gland-TH content was much less affected by PFOS treatment in bobwhite quail than would have been expected based on the degree of circulating TH depression that was observed. In Japanese quail, thyroid gland-TH content was decreased at 7 days of exposure but showed some recovery by 14 days of exposure compared to controls for these same times.

Key words: PFOS, thyroid, quail