PT14 Toxicity of Mixtures
Exhibit Hall
8:00 AM - Tuesday
(PT232) External heart deformities in passerines environmentally exposed to PCBs during development: Species and gender sensitivity.
Yeager, R1, DeWitt, J2, Millsap, D1, Heise, S1, Sparks, D3, Henshel, D1, 1 Indiana University, Bloomington, IN, USA2 University of North Carolina, Chapel Hill, NC, USA3 U.S. Fish and Wildlife Service, Bloomington, IN, USA
ABSTRACT- Previous studies demonstrated that avian species are sensitive to the cardiac teratogenicity of dioxin and dioxin-like chemicals. Necropsy-observable cardiac deformities in hearts were evaluated from nestling passerine birds (bluebirds, BB; Carolina chickadees, CC; house wrens, HW; red-winged black birds, RW; and tree swallows, TS) environmentally exposed in ovo and post-hatch to mixtures of polychlorinated biphenyls (PCBs). After fixation and necropsy, hearts were assessed for gross external deformities and measured (ventricular width, length, and depth). Observed deformities included pointed, rounded, or flattened tips, center rolls, macro- and micro-surface roughness, ventricular indentations, ventricular notches, visibly thin ventricular walls, and overall shape deformities. Overall, there was a positive correlation between PCB concentration and the frequency and severity of the external heart deformities. However, the response of each passerine species analyzed varied across the deformities and between genders. For example, the ventricular length was significantly (P ≤ 0.05) longer in BB hearts from the contaminated sites compared to the reference site and significantly (P ≤ 0.05) shorter in TS hearts from the contaminated site compared to the reference site. Similarly, the average number of deformities was greater in hearts from males than from females for all species but HW. These results indicate that while external heart surface and shape deformities are induced by developmental PCB exposure, no one species of passerine is an ideal sentinel and differences between genders may alter overall conclusions.
Key words: PCBs, Passerine, Heart, Development