Metabolism, excretion and distribution of the flame retardant tetrabromobisphenol-A in conventional and bile-duct cannulated rats.
1. 14C-TBBP-A (2,2-bis(4-hydroxy-3,5-dibromophenyl)propane) was administered orally to the conventional and bile-duct cannulated male Sprague-Dawley rat (2.0 mg/kg body weight). Urine, bile and faeces were collected daily for 72 h, and selected tissues were removed for distribution studies. 2. Faeces was the major route of elimination of TBBP-A in the conventional rat (91.7% of dose), and urine was a minor elimination route (0.3%). Enterohepatic circulation was suggested by biliary excretion of 71.3% and faecal excretion of 26.7% of the administered radioactivity in the bile-duct cannulated rat. 3. 14C-labelled residues in tissues were 2% in the conventional rat, and < 1% in the bile-duct cannulated rat. The large and small intestines contained the majority of the tissue 14C activity for both groups of rat. Levels of TBBP-A in liver were < 0.1% and in fat were below the level of quantification. 4. Three metabolites were characterized in 0-24 h bile samples. Glucuronic acid and sulphate ester conjugates were characterized by mass spectrometry. More than 95% of the extractable faecal 14C was identified as parent TBBP-A. 5. Negligible amounts of TBBP-A-derived 14C were associated with carrier proteins in the urine and bile.
Hakk
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H
US Department of Agriculture, Agricultural Research Service, Fargo, ND 58105, USA. hakkh@fargo.ars.usda.gov
Larsen
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G
Bergman
A
A
Orn
U
U
D000818:Animals; D001646:Bile / Q000737:chemistry; D001652:Bile Ducts; D002250:Carbon Radioisotopes; D002404:Catheterization; D005243:Feces / Q000737:chemistry; D005411:Flame Retardants / Q000032:analysis / Q000378:metabolism / Q000493:pharmacokinetics*; D020719:Glucuronides / Q000378:metabolism; D007422:Intestines / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008297:Male; D013058:Mass Spectrometry; D011075:Polybrominated Biphenyls / Q000032:analysis / Q000493:pharmacokinetics* / Q000652:urine; D051381:Rats; D017207:Rats, Sprague-Dawley; D013431:Sulfates / Q000378:metabolism; D014018:Tissue Distribution
D002250:Carbon Radioisotopes; D005411:Flame Retardants; D020719:Glucuronides; D011075:Polybrominated Biphenyls; D013431:Sulfates; C020806:tetrabromobisphenol A