Effected of insulin and insulin-like growth factor-I on glucose transport and its transporters in soleus muscle of lean and obese mice.
The mechanisms underlying insulin and insulin-like growth factor-I (IGF-I) action on glucose transport share similar processes leading to Glut 4 translocation after respective receptor activation. Among these steps are phosphorylation of insulin receptor substrate-1 (IRS-1) and activation of phosphatidylinositol-3-kinase (P13-kinase). This enzyme could be involved in stimulated glucose transport in muscle, since its inhibitor, wortmannin, blocks the hormonal effect in muscle. P13-kinase is activated by insulin and IGF-I in a rapid and transient manner in incubated soleus muscles. When P13-kinase activation was studied in muscle of obese insulin-resistant mice, there was a marked alteration in the response to insulin both in vivo and in vitro. P13-kinase activation by IGF-I was also altered in obese mice, although to a lesser degree.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D005947:Glucose / Q000378:metabolism*; D006614:Hindlimb; D007328:Insulin / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D012016:Reference Values
D007328:Insulin; D009004:Monosaccharide Transport Proteins; D007334:Insulin-Like Growth Factor I; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D005947:Glucose