Insulin receptor and glucose transporter mRNA expression in skeletal muscle of genetically obese Zucker rats.
Insulin resistance and defective glucose transport are associated with muscle tissue in the genetically obese Zucker rat and are accompanied by changes in the number of insulin receptors and the availability of glucose transporters. The present study was carried out to assess whether, in male Zucker rats at 10 weeks of age, these defects were reflected by changes in the levels of mRNAs for the insulin receptor and for the insulin responsive glucose transporter (GLUT-4). Total RNA was extracted from plantaris and soleus muscles and the levels of insulin receptor and GLUT-4 mRNAs and 18 S rRNA were determined by Northern hybridization and quantified by image analysis of the autoradiographs. A 50% increase in the level of insulin receptor mRNA was detected in both the plantaris and the soleus muscle from the obese rats compared to the lean rats. No change in the level of GLUT-4 mRNA was detected in the plantaris muscle although increases were observed in the soleus muscle from the obese rats.
Knott
R M
RM
Rowett Research Institute, Bucksburn, Aberdeen, Scotland, UK.
Hesketh
J E
JE
D000818:Animals; D015152:Blotting, Northern; D007328:Insulin / Q000097:blood; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000235:genetics*; D009132:Muscles / Q000378:metabolism*; D009765:Obesity / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D051381:Rats; D011924:Rats, Zucker / Q000235:genetics*; D011972:Receptor, Insulin / Q000235:genetics*
D007328:Insulin; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; D012337:RNA, Ribosomal, 18S; D011972:Receptor, Insulin