passages.id: 6518
passages.type: title
passages.text: Increased sulfation and decreased 7alpha-hydroxylation of deoxycholic acid in ethinyl estradiol-induced cholestasis in rats.
passages.id: 6519
passages.type: abstract
passages.text: Deoxycholic acid conjugation, transport capacity, and metabolism were compared in control and ethinyl estradiol-treated rats. Control rats were found to have a lower capacity to transport deoxycholic acid than taurodeoxycholic acid, and both were decreased by ethinyl estradiol treatment. During [24-14C]sodium deoxycholate infusion, [14C]biliary bile acid secretion increased, but bile flow did not change significantly in either control or ethinyl estradiol-treated rats. Ethinyl estradiol-treated animals excreted significantly less 14C as taurocholic acid than did control animals, consistent with an impairment of 7alpha-hydroxylation of taurodeoxycholic acid. Ethinyl estradiol treatment did not impair conjugation of deoxycholic acid, but did result in an increase in sulfation of taurodeoxycholic acid from 1.5% in controls to nearly 4.0% (P less than 0.01). These results are consistent with the hypothesis that the rat has a poorer tolerance for deoxycholic acid than do certain other species. Furthermore, the rat converts deoxycholic acid, a poor choleretic, to taurocholic acid, a good choleretic. When this conversion is impaired with ethinyl estradiol treatment, sulfation may be an important alternate pathway for excretion of this potentially harmful bile acid.