Saekow M, Olefsky J M
Endocrinology. 1980 Dec;107(6):2004-10. doi: 10.1210/endo-107-6-2004.
We have studied the effects of increased dietary carbohydrate content on glucose transport and intracellular glucose metabolism in adipocytes from spontaneously obese rats and from streptozotocin-induced insulin-deficient diabetic rats. Four groups of animals were studied: 1) obese rats on the control diet, 2) obese rats on the high carbohydrate diet, 3) diabetic rats on the control diet, and 4) diabetic rats on the high carbohydrate diet. Compared to the control diet, the high carbohydrate diet led to an increase in insulin secretion in the obese rats, whereas the diabetic animals were unable to respond to the diet with enhanced insulin output. In the diabetic animals, the rates of adipocyte glucose transport, glucose oxidation, and lipogenesis were low relative to those in nondiabetic controls and were not influenced by the high carbohydrate diet. In the obese animals on the control diet, absolute rates of glucose transport were similar to those of lean controls, but glucose oxidation and lipogenesis were depressed. On the high carbohydrate diet, all aspects of cellular glucose transport and metabolism were markedly increased. Thus, when plasma insulin levels were allowed to increase (obese animals), rates of cellular glucose metabolism increased; when plasma insulin was kept constant (diabetic rats) cellular glucose metabolism was unchanged. In conclusion, 1) a high carbohydrate diet leads to augmented rates of glucose transport, oxidation, and lipogenesis, provided the animal can respond to the increased dietary carbohydrate with increased insulin secretion, and 2) the diet-induced relative hyperinsulinemia most probably mediates the changes in cellular metabolism.
我们研究了饮食中碳水化合物含量增加对自发性肥胖大鼠和链脲佐菌素诱导的胰岛素缺乏型糖尿病大鼠脂肪细胞中葡萄糖转运和细胞内葡萄糖代谢的影响。研究了四组动物：1）食用对照饮食的肥胖大鼠，2）食用高碳水化合物饮食的肥胖大鼠，3）食用对照饮食的糖尿病大鼠，4）食用高碳水化合物饮食的糖尿病大鼠。与对照饮食相比，高碳水化合物饮食导致肥胖大鼠胰岛素分泌增加，而糖尿病动物对该饮食无法通过增加胰岛素分泌做出反应。在糖尿病动物中，脂肪细胞葡萄糖转运、葡萄糖氧化和脂肪生成的速率相对于非糖尿病对照较低，且不受高碳水化合物饮食影响。在食用对照饮食的肥胖动物中，葡萄糖转运的绝对速率与瘦对照相似，但葡萄糖氧化和脂肪生成受到抑制。在高碳水化合物饮食下，细胞葡萄糖转运和代谢的各个方面均显著增加。因此，当血浆胰岛素水平升高时（肥胖动物），细胞葡萄糖代谢速率增加；当血浆胰岛素保持恒定时（糖尿病大鼠），细胞葡萄糖代谢不变。总之，1）高碳水化合物饮食会导致葡萄糖转运、氧化和脂肪生成速率增加，前提是动物能够通过增加胰岛素分泌来应对饮食中碳水化合物的增加，2）饮食诱导的相对高胰岛素血症很可能介导了细胞代谢的变化。
