Anwer M S, Hegner D
Hoppe Seylers Z Physiol Chem. 1978 Feb;359(2):181-92.
The effect of Na on cholate and taurocholate uptake was studied in isolated rat hepatocytes. Uptake of both bile acids can be divided into three components: a) a non-saturable component independent of Na, b) a Na-independent saturable and c) a Na-dependent saturable component. The two saturable components were inhibited by KCN, oligomycin and various other bile acids, which suggests carrier-mediated, energy-requiring processes. The relationship between Na concentration and the Na-dependent uptake rate was sigmoidal. The maximal uptake rate, rather than the Km, was affected by Na. These results suggest that more than one Na (probably two) are cosubstrates in the transport of one bile acid molecule and Na exerts a stimulatory effect on the translocation of the bile acid-carrier complex across the membranes. The Na-dependent uptake was inhibited by ouabain, suggesting that this uptake process is linked to the activity of membrane bound (Na-K)ATPase. Inhibition and competition studies suggest that cholate and taurocholate share a common Na-independent transport system while there are at least two Na-dependent transport systems for taurocholate, one of which is shared by cholate.
在分离的大鼠肝细胞中研究了钠对胆酸盐和牛磺胆酸盐摄取的影响。两种胆汁酸的摄取均可分为三个部分：a）不依赖钠的非饱和成分，b）不依赖钠的饱和成分，以及c）依赖钠的饱和成分。这两种饱和成分均受到氰化钾、寡霉素和其他各种胆汁酸的抑制，这表明其为载体介导的、需要能量的过程。钠浓度与依赖钠的摄取速率之间的关系呈S形。最大摄取速率而非米氏常数受钠的影响。这些结果表明，在一个胆汁酸分子的转运过程中，不止一个钠（可能是两个）是共底物，并且钠对胆汁酸-载体复合物跨膜转运具有刺激作用。依赖钠的摄取受到哇巴因的抑制，这表明该摄取过程与膜结合的（钠-钾）ATP酶的活性有关。抑制和竞争研究表明，胆酸盐和牛磺胆酸盐共享一个共同的不依赖钠的转运系统，而牛磺胆酸盐至少有两个依赖钠的转运系统，其中一个由胆酸盐共享。
