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(18-79) Comparative Analysis of Developmental Exposure to Polybrominated Diphenylethers (PBDE) and PCB in Rats. Lichtensteiger, Walter*,1, Ceccatelli, Raffaella1, Faass, Oliver1, Fleischmann, Irčne1, Conscience, Marianne1, Schlumpf, Margret1, 1 Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland ABSTRACT- Polybrominated diphenylethers (PBDE) are widely used as flame retardants. Due to their biophysical properties and stability, they accumulate in the biosphere. In contrast to polychlorinated biphenyls (PCB), PBDE levels have been found to increase in human milk during the last decade. We are conducting a comparative study of the developmental toxicity of PBDE99 (2,2',4,4',5-PentaBDE) and of a PCB mixture (Aroclor 1254) in rats, with special emphasis on developing (neuro)endocrine systems. PCB affect sexual differentiation processes (Hany et al., 1999). PBDE99 (1 or 10 mg/kg/day) or Aroclor 1254 (10 or 30 mg/kg/day), dissolved in olive oil, was injected subcutaneously to time-pregnant Long Evans rats from gestational day 10 to 18 (vehicle control: olive oil). Aroclor 1254 but not PBDE99 affected survival rate of the offspring. Both, Aroclor 1254 and PBDE99 delayed the onset of puberty in females (vaginal opening), whereas male puberty (preputial separation) did not seem to be affected. Detailed analyses of reproductive organs and sexually dimorphic brain regions of adult, prenatally exposed offspring are under way. Possible long term effects on the expression of estrogen-regulated genes are quantified by Real Time PCR in reproductive organs and brain regions of both sexes. The preliminary observations on puberty indicate a possible interaction of PBDE with developmental processes. Supported by 5th Framework Program, Quality of Life and Management of Living Resources (PBDE-NTOX). Key words: polybrominated diphenylether (PBDE), polybrominated biphenyls (PCB) , development, rat |
