T6 PM Immune and Endocrine Disruption: Detection and Implication
Tuesday, 15 November 2005: 1:50 PM - 5:30 PM in 324-326
(QUI-1116-004626) Immunotoxicity of androgen active EDCs in Japanese quail.
Quinn, Jr., M1, Lavoie, E2, Thompson, N2, Touart, L3, Ottinger, M2, 1 U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD, USA2 University of Maryland, Animal and Avian Sciences, College Park, MD, USA3 US Environmental Protection Agency, Washington, DC, USA
ABSTRACT- Many mechanisms behind endocrine disrupting chemical (EDC)-induced immunosuppression remain unclear. Research has focused on EDCs that affect the estrogen and thyroid systems, leaving the androgen system, which is most often considered immunosuppressive, virtually untouched. This study helps to identify some of the immune organs targeted by androgen-active EDCs. We hypothesized that immunosuppression in birds that is caused by exposure to androgenic or anti-androgenic chemicals occurs mainly through disruption of the development of the bursa of Fabricius, an avian immune organ responsible for B cell maturation. Trenbolone acetate, a synthetic androgen, was injected in to the yolk of Japanese quail (Coturnix japonica) eggs at day 4 of incubation at 0.5, 5, 50, or 125 
g, and in a different set of eggs DDE, an anti-androgen, was injected at day 1 of incubation at 20.0 or 40.0 g. A sesame oil vehicle control was included. Spleens and bursas were collected and weighed at day of hatch and adulthood, and histological measurements were made. Humoral and cell-mediated responses were assessed in adults. Spleens from both chicks and adults appeared to be unaffected by either chemical. Bursas from chicks treated with DDE were larger than, had fewer follicles (site of B cell maturation), had loss of plicae, and exhibited vacuolization within follicles compared to controls. Bursas from chicks treated with trenbolone were smaller, had fewer follicles, had loss of plicae, and exhibited thicker epithelial layers between plicae conpared to controls. Bursas from adults that were embronically exposed to either chemical did not differ from controls. No differences were observed in either of the response tests. This study shows the bursa to be extremely sensitive to androgen-active EDCs and suggests that overall immunocompetence in the quail can be resilient to a one-time embryonic exposure to these chemicals.
Key words: endocrine disrupting chemicals, trenbolone acetate, p,p'-DDE, bursa of Fabricius