Wortmannin inhibits insulin-stimulated but not contraction-stimulated glucose transport activity in skeletal muscle.
In skeletal muscle, glucose transport is stimulated by insulin, contractions and hypoxia. In this study, we used the phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor wortmannin to examine whether (i) PI 3-kinase activity is necessary for stimulation of glucose transport by insulin in muscle, and (ii) PI 3-kinase mediates a step in the pathway by which contractions/hypoxia stimulate glucose transport. Wortmannin completely blocked insulin- and insulin-like growth factor-1-stimulated glucose transport in muscle. In contrast, wortmannin had no effect on the stimulation of glucose transport by contractions or hypoxia, providing evidence that PI 3-kinase activity is not involved in the activation of glucose transport by these stimuli.
Lee
A D
AD
Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110.
Hansen
P A
PA
Holloszy
J O
JO
D000730:Androstadienes / Q000494:pharmacology*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D015687:Cell Hypoxia; D046508:Culture Techniques; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects / Q000201:enzymology*; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D000077191:Wortmannin
D000730:Androstadienes; D007328:Insulin; D007334:Insulin-Like Growth Factor I; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D005947:Glucose; D000077191:Wortmannin