Mechanism of estrogen-induced saturated bile in the hamster
Bonorris, G.G.; Coyne, M.J.; Chung, A.; Schoenfield, L.J.
Journal of Laboratory and Clinical Medicine 90(6): 963-970
1977
ISSN/ISBN: 0022-2143 PMID: 925485 Document Number: 114001
Oral contraceptives increase the risk of CH synthesis, CH-7.alpha.-hydroxylase was determined. There were 24 male hamsters assigned to receive for 1 mo. the standard diet or the standard diet plus EE, 50 .mu.g/kg. At sacrifice biliary lipids were determined. Activities of hepatic microsomal HMG-CoAR and 7.alpha.-hydroxylase were assayed. Concentrations of hepatic BA and of free and esterified CH in total and microsomal hepatic fractions were measured. Biliary Sl in EE-treated hamsters, 1.12 .+-. 0.04, was greater (P < 0.01) than in the control group, 0.68 .+-. 0.03. HMG-CoAR activity with EE treatment, 299 .+-. 12.3 pmol/mg per min, was not different from control values, 300 .+-. 9.5 pmol/mg per min, 7.alpha.-hydroxylase was less (P < 0.01) with EE treatment, 14.7 .+-. 1.6 pmol/mg per min, than in the control, 23.0 .+-. 1.1 pmol/mg per min. EE treatment did not change the amount of esterified CH in total liver tissue from control, 3.92 .+-. 0.16 .mu.mol/gm or in the microsomal fraction from control, 0.034 .+-. 0.003 .mu.mol/mg. EE treatment did not change hepatic BA from control values, 253 .+-. 10.4 nmol/mg. EE increase of Sl apparently was associated with inhibition of BA synthesis without effect on CH synthesis, and the absence of EE-induced changes in hepatic CH and BA concentrations suggested that this decreased BA synthesis may result from mechanisms other than altered substrate or increased BA feedback.