title: Absorption and biotransformation of polybrominated diphenyl ethers DE-71 and DE-79 in chicken (Gallus gallus), mallard (Anas platyrhynchos), American kestrel (Falco sparverius) and black-crowned night-heron (Nycticorax nycticorax) eggs.
abstract: We recently reported that air cell administration of penta-brominated diphenyl ether (penta-BDE; DE-71) evokes biochemical and immunologic effects in chicken (Gallus gallus) embryos at very low doses, and impairs pipping (i.e., stage immediately prior to hatching) and hatching success at 1.8mugg(-1) egg (actual dose absorbed) in American kestrels (Falco sparverius). In the present study, absorption of polybrominated diphenyl ether (PBDE) congeners was measured following air cell administration of a penta-BDE mixture (11.1mug DE-71g(-1) egg) or an octa-brominated diphenyl ether mixture (octa-BDE; DE-79; 15.4mug DE-79g(-1) egg). Uptake of PBDE congeners was measured at 24h post-injection, midway through incubation, and at pipping in chicken, mallard (Anas platyrhynchos), and American kestrel egg contents, and at the end of incubation in black-crowned night-heron (Nycticorax nycticorax) egg contents. Absorption of penta-BDE and octa-BDE from the air cell into egg contents occurred throughout incubation; at pipping, up to 29.6% of penta-BDE was absorbed, but only 1.40-6.48% of octa-BDE was absorbed. Higher brominated congeners appeared to be absorbed more slowly than lower brominated congeners, and uptake rate was inversely proportional to the log K(ow) of predominant BDE congeners. Six congeners or co-eluting pairs of congeners were detected in penta-BDE-treated eggs that were not found in the dosing solution suggesting debromination in the developing embryo, extraembryonic membranes, and possibly even in the air cell membrane. This study demonstrates the importance of determining the fraction of xenobiotic absorbed into the egg following air cell administration for estimation of the lowest-observed-effect level.
authors.affiliation: Marine, Estuarine and Environmental Sciences and Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA.
authors.forename: Moira A
authors.initials: MA
authors.lastname: McKernan
authors.forename: Barnett A
authors.initials: BA
authors.lastname: Rattner
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Hatfield
authors.forename: Robert C
authors.initials: RC
authors.lastname: Hale
authors.forename: Mary
authors.initials: M
authors.lastname: Ann Ottinger
mesh_terms: D000042:Absorption; D000818:Animals; D001711:Biotransformation; D001717:Birds / Q000254:growth & development / Q000378:metabolism*; D002645:Chickens / Q000254:growth & development / Q000378:metabolism*; D004372:Ducks / Q000254:growth & development / Q000378:metabolism*; D004785:Environmental Pollutants / Q000378:metabolism* / Q000633:toxicity; D055768:Halogenated Diphenyl Ethers / Q000378:metabolism* / Q000633:toxicity; D010063:Ovum / Q000737:chemistry / Q000187:drug effects; D011075:Polybrominated Biphenyls / Q000378:metabolism* / Q000633:toxicity
chemical_list: D004785:Environmental Pollutants; D055768:Halogenated Diphenyl Ethers; D011075:Polybrominated Biphenyls; C086401:pentabromodiphenyl ether