Biliary transport of glutathione disulfide studied with isolated rat-liver canalicular-membrane vesicles.
Biliary transport of glutathione disulfide studied with isolated rat-liver canalicular-membrane vesicles.
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用分离的大鼠肝小管膜囊泡研究谷胱甘肽二硫化物的胆道转运。
DOI：
10.1111/j.1432-1033.1984.tb08177.x
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Arias,IM
中科院分区：
文献类型：
--
作者：
Akerboom,T;Inoue,M;Sies,H;Kinne,R;Arias,IM
使用从大鼠肝脏（右侧朝外）分离的小管质膜囊泡来研究谷胱甘肽二硫化物（GSSG）的转运。 GSSG 被输送到渗透敏感室中。外推至无穷大的外部渗透压表明孵育 10 分钟后结合率为 35%，例如作为膜蛋白中谷胱甘肽和 SH 基团之间的混合二硫化物。在 KCl 或 NaCl 存在的情况下，谷胱甘肽二硫化物的摄取以相同的速率进行。平衡后，未发现跨小管膜的显着 GSSG 浓度梯度。摄取的温度依赖性与 GSSG (Q10×1.6) 的载体介导的运输一致，并且似乎排除了简单扩散。GSSG 摄取的浓度依赖性显示浓度高达 1 mM 时的 Michaelis-Menten 动力学；计算 0.4 mM 的 aKm 和 1.1 nmol × min−1× mg Protein−1 的 aV。在较高浓度下，在没有饱和动力学的情况下观察到线性依赖性。得出的结论是，谷胱甘肽二硫化物的转运是由肝细胞小管膜中存在的载体介导的。
Canalicular plasma membrane vesicles isolated from rat liver (right side out) were used to study glutathione disulfide (GSSG) transport. GSSG is transported into an osmotically sensitive compartment. Extrapolation to an external osmolarity of infinity indicates 35% binding after 10 min of incubation, e.g. as mixed disulfides between glutathione and SH‐groups in membrane proteins.Glutathione disulfide uptake occurred with equal rates in the presence of KCl or NaCl. After equilibration, no significant GSSG concentration gradient across the canalicular membrane was found. The temperature dependence of uptake is consistent with a carrier‐mediated transport for GSSG (Q10× 1.6) and seems to exclude simple diffusion Concentration dependence of GSSG uptake shows Michaelis‐Menten kinetics at concentrations up to 1 mM; aKmof 0.4 mM and aVof 1.1 nmol × min−1× mg protein−1is calculated. At higher concentrations a linear dependence is observed without saturation kinetics.It is concluded that transport of glutathione disulfide is mediated by a carrier present in the canalicular membrane of the hepatocyte.