Glucose transporter (GLUT 4) content and insulin receptor kinase activity in muscles of the LA/N-cp rat.
In this study we compared insulin binding activity, insulin receptor tyrosine kinase activity, and GLUT 4 protein content in six muscles from LA/N-cp rats and their lean controls. LA/N-cp rats had an approximate 20-fold increase in insulin concentration (837 +/- 113 vs 40 +/- 1), associated with significant (p < 0.01) decreases in both insulin binding activity per mg muscle and in muscle GLUT 4 content. Maximum insulin tyrosine kinase activity was also lower in muscle from LA/N-cp rats, but no difference was noted when tyrosine kinase activity was expressed per receptor. These data indicate that there are at least two defects in the insulin action cascade in muscle from LA/N-cp rats that contribute to the insulin resistance in these animals.
Kern
M
M
Department of Medicine, Stanford University School of Medicine, California.
Mondon
C
C
Butte
J C
JC
Azhar
S
S
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D051275:Glucose Transporter Type 4; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D007333:Insulin Resistance; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009124:Muscle Proteins; D009132:Muscles / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism*; D051381:Rats; D011922:Rats, Mutant Strains; D011972:Receptor, Insulin / Q000378:metabolism*
D001786:Blood Glucose; D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; C495694:Slc2a4 protein, rat; D011972:Receptor, Insulin