Cartee G D
Biodynamics Laboratory, University of Wisconsin-Madison.
J Gerontol. 1993 Jul;48(4):B168-70. doi: 10.1093/geronj/48.4.b168.
Age-related changes in glucose metabolism and glucose transporter protein content have been described in adipose tissue and skeletal muscle, two tissues that express the GLUT-4 isoform of the glucose transporter protein. I studied the effect of age on the levels of GLUT-4 protein in a third insulin-sensitive tissue: the heart. Cardiac ventricles were sampled from male Fischer 344/Brown Norway F1 hybrid (F344/BNNia) rats. The total protein concentration of the left ventricle did not change with age. GLUT-4 levels per mg of protein declined by 15% between 3.5 and 13 months of age, and by another 12% during adulthood (between 13 and 25 months of age); when expressed per g wet weight, the decreases were 13% and 17%, respectively. Linear regression analysis revealed a significant (p < .0001) relationship (r2 = .634) between age and myocardial GLUT-4. These results demonstrate that the GLUT-4 levels in the left ventricle decrease in an age-related fashion and suggest that the capacity for glucose transport might also be reduced.
脂肪组织和骨骼肌这两种表达葡萄糖转运蛋白GLUT - 4亚型的组织中，已发现存在与年龄相关的葡萄糖代谢变化以及葡萄糖转运蛋白含量变化。我研究了年龄对第三种胰岛素敏感组织——心脏中GLUT - 4蛋白水平的影响。从雄性Fischer 344/棕色挪威F1杂交（F344/BNNia）大鼠采集心室样本。左心室的总蛋白浓度不随年龄变化。每毫克蛋白的GLUT - 4水平在3.5至13月龄之间下降了15%，成年期（13至25月龄之间）又下降了12%；以每克湿重表示时，下降幅度分别为13%和17%。线性回归分析显示年龄与心肌GLUT - 4之间存在显著关系（p < .0001）（r2 = .634）。这些结果表明，左心室中的GLUT - 4水平以与年龄相关的方式下降，提示葡萄糖转运能力可能也会降低。
