Seki Yoshinori, Berggren Jason R, Houmard Joseph A, Charron Maureen J
Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Med Sci Sports Exerc. 2006 Jun;38(6):1088-92. doi: 10.1249/01.mss.0000222837.74015.f1.
Two recently identified glucose transporters, GLUT8 and GLUT12, are expressed in human skeletal muscle and may be involved in insulin-mediated sugar transport.
The purpose of this study was to measure GLUT8 and GLUT12 mRNA levels in endurance-trained versus sedentary individuals in an effort to determine the effect of repeated days of contractile activity on gene expression.
GLUT 4, 8, and 12 mRNA were measured in biopsies from the vastus lateralis using quantitative real-time PCR in endurance-trained (N=16, age=22.0+/-0.9 yr, VO(2 max) (L.min(-1))=4.13+/-0.25) and sedentary (N=15, age=21.3+/-0.8 yr, VO(2 max) (L.min(-1))=3.21+/-0.24) subjects.
GLUT12 mRNA was lower (40+/-14%, P<0.05) in the exercise-trained compared with the sedentary subjects. There was no difference between groups in GLUT8 mRNA content. mRNA of the insulin-sensitive glucose transporter (GLUT4) was 78+/-27% (P<0.05) higher in skeletal muscle from endurance-trained compared with sedentary individuals.
These findings suggest an isoform-specific effect on the mRNA of the glucose transporters in human skeletal muscle with repeated days of contractile activity.
最近发现的两种葡萄糖转运蛋白，即GLUT8和GLUT12，在人类骨骼肌中表达，可能参与胰岛素介导的糖转运。
本研究旨在测量耐力训练者与久坐不动者的GLUT8和GLUT12 mRNA水平，以确定连续多日的收缩活动对基因表达的影响。
采用定量实时PCR法，测量了耐力训练组（N = 16，年龄 = 22.0±0.9岁，最大摄氧量（L·min⁻¹）= 4.13±0.25）和久坐不动组（N = 15，年龄 = 21.3±0.8岁，最大摄氧量（L·min⁻¹）= 3.21±0.24）受试者股外侧肌活检样本中的GLUT4、8和12 mRNA。
与久坐不动的受试者相比，耐力训练者的GLUT12 mRNA水平较低（40±14%，P<0.05）。两组之间的GLUT8 mRNA含量没有差异。与久坐不动的个体相比，耐力训练者骨骼肌中胰岛素敏感型葡萄糖转运蛋白（GLUT4）的mRNA水平高78±27%（P<0.05）。
这些发现表明，连续多日的收缩活动对人类骨骼肌中葡萄糖转运蛋白的mRNA具有亚型特异性影响。
