Höller M, Weber H, Breuer H
Acta Endocrinol (Copenh). 1982 Jun;100(2):274-8.
The uptake of [4-14C]oestriol by the isolated perfused rat liver is 3.8 times faster as compared to that of simultaneously perfused [6,9-3H2]oestriol 16 alpha-monoglucuronide. During perfusion the concentration of both radioactive oestrogens decreased exponentially in perfusion medium (apparent kel: 0.061 min-1 and 0.016 min-1, respectively). [6,9-3H2]Oestriol 16 alpha-monoglucuronide was metabolized only to a small extent; more than 92% was secreted unchanged into the bile where it was highly concentrated (1800 nmol/g). In contrast [4-14C]oestriol was extensively metabolized; it was mainly hydroxylated at C-atom 2, leading to a rapid increase in the concentration of 2-hydroxyoestriol in the perfused medium. This metabolite was quickly taken up by the liver during recirculation and subsequently either methylated or sulphated. 2-Hydroxyoestriol monosulphate was glucuronated to 2-hydroxyoestriol 16 alpha-monoglucuronide 3-sulphate, which was rapidly excreted into the bile. No double conjugate was formed when [6,9-3H2]oestriol 16 alpha-monoglucuronide was perfused; this is additional evidence for the correctness of the assumption that monoglucuronides cannot serve as precursors of sulphoglucuronides.
与同时灌注的[6,9 - 3H₂]雌三醇16α - 葡萄糖醛酸苷相比，分离的灌注大鼠肝脏对[4 - ¹⁴C]雌三醇的摄取速度快3.8倍。在灌注过程中，两种放射性雌激素在灌注介质中的浓度呈指数下降（表观消除速率常数：分别为0.061 min⁻¹和0.016 min⁻¹）。[6,9 - 3H₂]雌三醇16α - 葡萄糖醛酸苷仅少量代谢；超过92%以未改变的形式分泌到胆汁中，在胆汁中高度浓缩（1800 nmol/g）。相比之下，[4 - ¹⁴C]雌三醇被广泛代谢；它主要在C - 2原子处羟基化，导致灌注介质中2 - 羟基雌三醇的浓度迅速增加。这种代谢产物在再循环过程中被肝脏迅速摄取，随后甲基化或硫酸化。2 - 羟基雌三醇单硫酸盐被葡萄糖醛酸化生成2 - 羟基雌三醇16α - 葡萄糖醛酸苷3 - 硫酸盐，后者迅速排泄到胆汁中。当灌注[6,9 - 3H₂]雌三醇16α - 葡萄糖醛酸苷时未形成双共轭物；这是单葡萄糖醛酸苷不能作为硫酸葡萄糖醛酸苷前体这一假设正确性的额外证据。
