Marine, Estuarine and Environmental Sciences and Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA.
Chemosphere. 2010 Mar;79(1):100-9. doi: 10.1016/j.chemosphere.2009.12.023. Epub 2010 Jan 15.
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.
我们最近报道，五溴二苯醚（penta-BDE；DE-71）经气室途径给予极低剂量时，可引起鸡（Gallus gallus）胚胎的生化和免疫效应，并在 1.8mugg(-1) 蛋（实际吸收剂量）时损害出壳（即出壳前的阶段）和出壳成功率。在美国红隼（Falco sparverius）中。在本研究中，在气室给予五溴二苯醚混合物（11.1mug DE-71g(-1) 蛋）或八溴二苯醚混合物（八溴二苯醚；DE-79；15.4mug DE-79g(-1) 蛋）后，测量多溴二苯醚同系物的吸收情况。在注射后 24 小时、孵化中期和鸡、绿头鸭（Anas platyrhynchos）和美国红隼卵内容物出壳时以及在黑冠夜鹭（Nycticorax nycticorax）卵内容物孵化结束时测量 PBDE 同系物的摄取量。五溴二苯醚和八溴二苯醚从气室进入卵内容物的吸收在整个孵化过程中都在进行；在出壳时，多达 29.6%的五溴二苯醚被吸收，但只有 1.40-6.48%的八溴二苯醚被吸收。较高溴化的同系物似乎比较低溴化的同系物吸收得更慢，吸收速率与主要 BDE 同系物的 log K(ow)成反比。在五溴二苯醚处理的卵中检测到六种同系物或共洗脱对同系物，而在给药溶液中未发现这些同系物，这表明在发育中的胚胎、胚胎外膜甚至气室膜中发生脱溴。这项研究表明，在确定经气室给予后进入卵中的外来物质的吸收分数对于估计最低观察到的效应水平非常重要。
