Study on the Mechanism of the Translocation of Glucose Transporter by Insulin

Insulin stimulates glucose transport in muscle cell and adipocyte via the rapid redistribution of GLUT4 glucose transporters from intracellular membrane compartments to the cell surface. The mechanism that insulin treggers the translocation of glucose transporters in not known yet whether it is due to the structural differences among glucose transporters or there is cell specific targetting/translocation apparatus insulin-sensitive cells.

This study was planned to examine this question by strdying insulin effect on the glucose transport rate at adipocyte and hepatocyte fused with GLUT1 vesicle, respecitively.

The results showed that treatment of 37nM insulin increased the transport rate of 3-0-methylglucose by 3.8-fold at adipocyte fused with GLUT1 but increased lnly by 1.2-fold at hepatocyte fused with GLUT1.

Therefore, it is suggested that insulin sensitive cell has a cell-specific targetting/translocation machinery which is triggered by insulin-insulin receptor interaction but insulin sensitivity may not dependent on isoform(structural)-specific manner.