Effect of high-fat diet on gene expression of GLUT4 and insulin receptor in soleus muscle.
Gene expression of GLUT4 and insulin receptor in soleus muscle of high-fat and high-carbohydrate diet fed rats was studied by measuring mRNA. High-fat diet feeding increased plasma glucose but decreased plasma insulin level. Glucose uptake in soleus muscle measured by 2-deoxy-D-glucose technique was lower in high-fat than high-carbohydrate diet fed rats. GLUT4 mRNA level in soleus muscle was significantly decreased but insulin receptor mRNA was similar in high-fat compared with high-carbohydrate diet fed rats. Insulin receptor exists in two forms generated by alternative splicing of a primary gene transcript. There was no difference in the relative expression of insulin receptor isoform mRNAs between high-fat and high-carbohydrate diet fed rats. These results suggest that high-fat diet impairs glucose metabolism in muscle by reducing transcription of GLUT4 without affecting gene expression of insulin receptor.
Laboratory of Biochemistry of Exercise and Nutrition, University of Tsukuba, Japan.
Y
Y
Kim
T
T
Tamura
S
S
Iwashita
K
K
Tokuyama
M
M
Suzuki
D017398:Alternative Splicing; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004041:Dietary Fats; D005091:Exons; D005230:Fatty Acids, Nonesterified / Q000097:blood; D015870:Gene Expression; D051275:Glucose Transporter Type 4; D007328:Insulin / Q000097:blood; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000096:biosynthesis*; D009124:Muscle Proteins; D009132:Muscles / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011972:Receptor, Insulin / Q000096:biosynthesis*; D014158:Transcription, Genetic; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005230:Fatty Acids, Nonesterified; D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D012333:RNA, Messenger; C495694:Slc2a4 protein, rat; D014280:Triglycerides; D002784:Cholesterol; D011972:Receptor, Insulin