Kono T
Int J Obes. 1985;9 Suppl 1:105-8.
Several lines of recent evidence indicate that in the absence of insulin glucose transport activity in the basal form of adipocytes is mostly associated with certain intracellular vesicles, and that the function of insulin is to translocate the glucose transport activity from the intracellular storage site to the plasma membrane. Upon sucrose density gradient centrifugation, the two subcellular structures associated with the glucose transport activity were fractionated into the plasma membrane-rich and Golgi-rich fractions. In our laboratory, the glucose transport activity in the subcellular fractions was assayed after reconstruction into egg lecithin liposomes. The apparent translocation of the glucose transport activity from the storage site to the plasma membrane was reversible, energy dependent, protein synthesis independent, almost completed in 5-10 min at 37 degrees C when the hormone concentration was 1 nM, and very slow at a low temperature (for example 15 degrees C). These results are consistent with the hypothesis that insulin regulates glucose transport activity in adipocytes by causing translocation of the glucose transport apparatus in a reversible manner, and that the translocation, or recycling, of the glucose transport apparatus is brought about by exo- and endocytosis.
最近的几条证据表明，在缺乏胰岛素的情况下，脂肪细胞基础形式的葡萄糖转运活性大多与某些细胞内囊泡相关，并且胰岛素的功能是将葡萄糖转运活性从细胞内储存部位转运至质膜。经蔗糖密度梯度离心后，与葡萄糖转运活性相关的两种亚细胞结构被分离到富含质膜的组分和富含高尔基体的组分中。在我们实验室，亚细胞组分中的葡萄糖转运活性在重构到卵磷脂脂质体后进行测定。葡萄糖转运活性从储存部位到质膜的明显转运是可逆的、能量依赖的、不依赖蛋白质合成的，当激素浓度为1 nM时，在37℃下5 - 10分钟内几乎完成，而在低温（例如15℃）下非常缓慢。这些结果与以下假设一致：胰岛素通过以可逆方式引起葡萄糖转运装置的转运来调节脂肪细胞中的葡萄糖转运活性，并且葡萄糖转运装置的转运或循环是由胞吐作用和胞吞作用实现的。
