INSULIN RESPONSIVENESS IN SKELETAL-MUSCLE IS DETERMINED BY GLUCOSE TRANSPORTER (GLUT4) PROTEIN LEVEL
INSULIN RESPONSIVENESS IN SKELETAL-MUSCLE IS DETERMINED BY GLUCOSE TRANSPORTER (GLUT4) PROTEIN LEVEL
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DOI：
10.1042/bj2700397
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发表时间：
1990-09-01
影响因子：
4.1
通讯作者：
DOHM, GL
中科院分区：
文献类型：
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作者：
KERN, M;WELLS, JA;DOHM, GL
骨骼肌中的葡萄糖转运由两种不同的转运蛋白亚型介导，称为肌肉/脂肪葡萄糖转运蛋白（Glut 4）和红细胞/HepG 2/脑葡萄糖转运蛋白（Glut 1），其在丰度和膜分布上都不同。本研究旨在探讨红肌和白色肌胰岛素反应性的差异是否可能是由于葡萄糖转运蛋白亚型的差异表达。在雄性Sprague-Dawley大鼠（体重2.5 g）的四头肌和腓肠肌的红色和白色部分中测定葡萄糖转运以及Glut 1和Glut 4蛋白和mRNA水平。约250 g）。最大葡萄糖转运（响应于100 nM-胰岛素）在灌注后肢是3.6倍以上的红色比白色肌肉。红色肌肉包含约。与白色肌相比，总Glut 4蛋白和Glut 4 mRNA的水平高5倍，但Glut 1蛋白或mRNA水平在纤维类型之间没有差异。 我们的数据表明，在特定的骨骼肌纤维类型的葡萄糖转运的反应性的差异可能取决于Glut 4蛋白的量。由于这种蛋白质在骨骼肌的葡萄糖转运中起着不可或缺的作用，因此其表达的任何损伤都可能在胰岛素抵抗中起作用。
Glucose transport in skeletal muscle is mediated by two distinct transporter isoforms, designated muscle/adipose glucose transporter (Glut4) and erythrocyte/HepG2/brain glucose transporter (Glut1), which differ in both abundance and membrane distribution. The present study was designed to investigate whether differences in insulin responsiveness of red and white muscle might be due to differential expression of the glucose transporter isoforms. Glucose transport, as well as Glut1 and Glut4 protein and mRNA levels, were determined in red and white portions of the quadriceps and gastrocnemius muscles of male Sprague-Dawley rats (body wt. approx. 250 g). Maximal glucose transport (in response to 100 nM-insulin) in the perfused hindlimb was 3.6 times greater in red than in white muscle. Red muscle contained approx. 5 times more total Glut4 protein and 2 times more Glut4 mRNA than white muscle, but there were no differences in the Glut1 protein or mRNA levels between the fibre types. Our data indicate that differences in responsiveness of glucose transport in specific skeletal muscle fibre types may be dependent upon the amount of Glut4 protein. Because this protein plays such an integral part in glucose transport in skeletal muscle, any impairment in its expression may play a role in insulin resistance.