Bisphenol A glucuronide, a major metabolite in rat bile after liver perfusion

The environmental estrogen bisphenol A, orally introduced into the body, pa sses through the liver and modulates the endocrine system to elicit irrever sible changes in the functioning of reproduction. To elucidate the actual a nd dynamic metabolism of bisphenol A in the liver before its arrival at tar get organs, this study evaluated the metabolism and disposition of the comp ound within the passage through the liver in Sprague-Dawley rats. On perfus ion of 7.5 mu mol of bisphenol A into the liver via the portal vein, approx imately 91% of the infused bisphenol A was absorbed by the liver tissue, an d about 65% of the absorbed bisphenol A was glucuronidated within 60 min. R oughly 65% of the bisphenol A glucuronide that formed in the liver was excr eted into the bile and about 35% into the hepatic vein. On perfusion of 0.0 1, 0.05, and 0.1 mM bisphenol A solution into the liver, free bisphenol A w as excreted only into the vein at 5.6, 9.3, and 14.6%, respectively, of the total bisphenol A. These results suggest that most bisphenol A absorbed by the intestine is probably glucuronidated exclusively in the liver and the conjugate is excreted mainly into the bile.