You are here:
Disposition of the brominated flame retardant HBCD alpha and gamma in developing mice over time
Citation:
DILIBERTO, J. J., D. SZABO, J. Huwe, AND L. S. BIRNBAUM. Disposition of the brominated flame retardant HBCD alpha and gamma in developing mice over time. Presented at Society of Toxicology 49th Annual meeting, Salt Lake City, UT, March 07 - 11, 2010.
Impact/Purpose:
This study examines the dispostion of HBCD alpha derived radioactivity and HBCD gamma derived radioactivity in developing C57BL/6 mice following a single oral dose (3 mg/kg) at PNDIO over time.
Description:
Hexabromocyclododecane (HBCD) is a developmental neurotoxicant in mice following a single exposure on postnatal day 10 (PND 10). HBCD is a mixture of 3 stereoisomers, alpha (a), beta (~) and gamma (y). Evidence oftoxicity and lack of stereoisomer studies drives the importance of toxicokinetics in potentially susceptible populations. This study investigated disposition of 14C HBCD a or y in developing (PND 10) and adult (PND60) C57BLl6 female mice following a single oral dose (3mg/kg); tissues were collected 4 days post exposure. Results showed toxicokinetic differences of HBCD a and y in pups and as compared to adult mice; whereas disposition patterns were similar. HBCD a derived radioactivity was distributed primarily to lipophilic tissues with tissue concentrations (% dose/g tissue) highest in adipose (5.0 PNDIO; 3.7 PND60), liver (3.8 PNDlO; 2.7 PND60), muscle (3.4 PNDIO; 2.7 PND60), skin (3.2 PNDI0; 2.5 PND60), blood (1.5 PNDIO; 1.1 PND60), brain (0.8 PNDIO; 0.6 PND60). In contrast, HBCD y derived radioactivity did not distribute primarily to lipophilic tissues and values were lower (~50%) with tissue concentrations ofHBCD y highest in liver (2.8 PND10; 0.28 PND60), fat (1.8 PNDI0; 0.001 PND60), blood (0.7 PNDI0; 0.08 PND60), muscle (0.48 PND10; 0.001 PND60), brain (0.002 PNDIO; 0.0001 PND60). Selective metabolism differences may help explain higher levels of HBCD a seen in adults. Higher concentrations in pups suggest a reduced capacity to eliminate HBCD a and 't-These differences lead to higher concentrations in target tissues during critical windows of development. This may ultimately explain the sensitivity of developing animals to adverse effects ofHBCD. This abstract does not reflect USEPA, USDA, and NCIINIEHS policies. Supported by NIH Training Grant T32-ES07126 and EPACR833237