REDUCED CONTENT AND PRESERVED TRANSLOCATION OF GLUCOSE-TRANSPORTER (GLUT-4) IN WHITE ADIPOSE-TISSUE OF OBESE MICE

We investigated glucose transporters (GLUT 1 and GLUT 4) in subcellula r membrane fractions of white adipose tissue (WAT) of insulin-resistan t obese aurothioglucose (AuTG)- or monosodium glutamate (MSG)-treated mice. In vivo insulin stimulation (0.75 U/kg, EV) promoted, 10 min lat er, no significant change on glycemia of both AuTG and MSG obese mice, but control mice showed a decrease of 30% (p<0.001). Basal GLUT 4 con tent in WAT of obese mice was reduced by 40% (p<0.001) when compared t o that of nonobese mice. Insulin-stimulated GLUT 4 content was signifi cantly (p<0.01) higher in plasma membrane fraction and lower in micros omal fraction when compared to respective basal values, in all groups. Although the absolute values of GLUT 4 were lower in membrane fractio ns of obese mice, the relative changes stimulated by insulin were simi lar among the groups. No effect of obesity or insulin stimulation was observed upon GLUT 1 content. We conclude that WAT of insulin-resistan t obese AuTG- and MSG-treated mice has a decreased GLUT 4, but not GLU T 1, content, and the in vivo insulin-stimulated GLUT 4 translocation is preserved.