Karnieli E, Moscona R, Rafaeloff R, Illouz Y G, Armoni M
Department of Medicine C, Rambam Medical Center, Haifa, Israel.
Am J Physiol. 1989 Jan;256(1 Pt 1):E179-85. doi: 10.1152/ajpendo.1989.256.1.E179.
Obesity is known to be associated with insulin resistance in human and rat adipocytes. However, it is not known what are the perturbations in insulin action that contribute to disproportional femoral obesity. Thus femoral subcutaneous adipose tissue was obtained from lean women with various degrees of disproportional obesity, by liposuction. 3-O-methylglucose (3-O-methyl-D-glucopyranose) transport was measured in intact cells, and glucose transporter levels in plasma and low-density microsomal membranes were assessed using the cytochalasin B binding assay. A sixfold cellular enlargement was associated with increase in both basal and insulin-stimulated glucose transport activity in the intact cell, and a 300-600% increase in insulin stimulating effect per se. However, when glucose transporter levels were assessed, this cellular enlargement was accompanied by a 40-70% transporter depletion (in largest cells compared with smallest ones) in both subcellular fractions examined, from either basal or insulin-stimulated cells. This discrepancy, between increasing cellular glucose transport rates and relative depletion of transporter levels, suggests that these cells are not insulin resistant, as could be expected from their large size. A role for other factor(s), additional to glucose transporter levels, in the regulation of cellular glucose uptake rate is thus suggested.
众所周知，肥胖与人类和大鼠脂肪细胞中的胰岛素抵抗相关。然而，尚不清楚导致股部肥胖不成比例的胰岛素作用扰动是什么。因此，通过抽脂从患有不同程度股部肥胖不成比例的瘦女性身上获取股部皮下脂肪组织。在完整细胞中测量3 - O - 甲基葡萄糖（3 - O - 甲基 - D - 吡喃葡萄糖）转运，并使用细胞松弛素B结合试验评估血浆和低密度微粒体膜中的葡萄糖转运蛋白水平。细胞体积增大六倍与完整细胞中基础和胰岛素刺激的葡萄糖转运活性增加相关，并且胰岛素刺激作用本身增加300 - 600%。然而，当评估葡萄糖转运蛋白水平时，在检查的两个亚细胞组分中，无论是基础细胞还是胰岛素刺激的细胞，这种细胞体积增大都伴随着转运蛋白减少40 - 70%（最大细胞与最小细胞相比）。细胞葡萄糖转运速率增加与转运蛋白水平相对减少之间的这种差异表明，这些细胞并不像预期的那样因体积大而具有胰岛素抵抗性。因此，提示除了葡萄糖转运蛋白水平外，其他因素在调节细胞葡萄糖摄取速率中起作用。
