Feldman J M, Hilf R
Biochim Biophys Acta. 1985 May 30;845(2):265-71. doi: 10.1016/0167-4889(85)90186-7.
Purified plasma membrane vesicles isolated from R3230AC rat mammary tumors displayed carrier-mediated and stereospecific uptake. Uptake was shown to be proportional to protein concentration, sensitive to increasing osmolarity, and inhibited only by substrates entering by the same carrier. Carrier-mediated glucose uptake was inhibited rapidly by estradiol-17 beta and phloretin in a dose-dependent manner, whereas proline uptake was not affected by estradiol-17 beta. The data suggest that the inhibition of glucose by estradiol and phloretin, originally observed in whole cells, occurs by an interaction of the steroid with a component on the plasma membrane. In contrast, the lack of effects of estradiol on proline transport into vesicles implies that intracellular components may have mediated the estrogen-induced effects observed in whole cells.
从R3230AC大鼠乳腺肿瘤中分离出的纯化质膜囊泡表现出载体介导的立体特异性摄取。摄取与蛋白质浓度成正比，对渗透压升高敏感，并且仅被通过同一载体进入的底物抑制。载体介导的葡萄糖摄取被雌二醇-17β和根皮素以剂量依赖性方式迅速抑制，而脯氨酸摄取不受雌二醇-17β影响。数据表明，最初在全细胞中观察到的雌二醇和根皮素对葡萄糖的抑制作用是通过类固醇与质膜上的一种成分相互作用而发生的。相反，雌二醇对脯氨酸转运到囊泡中缺乏影响，这意味着细胞内成分可能介导了在全细胞中观察到的雌激素诱导的效应。
