[Effect of free fatty acids on glucose transporter 4 and insulin signaling proteins in rat skeletal muscle cells].
OBJECTIVE
To investigate the effect of free fatty acids on glucose transpoter4 (GLUT4) and insulin signaling proteins Grb2 and ERK2 in rat skeletal cells.


METHODS
After the skeletal muscle cells of Sprague-Dawley rats were incubated with palmitate (0.25 mmol/L) or oleate (0.125 mmol/L) for 12, 24 and 36 hours, Western blotting was used to assess the levels of GLUT4 and insulin signaling proteins Grb2 and ERK2. The level of GLUT4 RNA was determined by dot blotting.


RESULTS
The protein and RNA contents of GLUT4 were significantly decreased (P < 0.05) and the protein levels of Grb2 and ERK2 were decreased also compared with control in rat skeletal muscle cells after incubated with free fatty acids for 12, 24 and 36 hours (P < 0.05).


CONCLUSIONS
Free fatty acids inhibit glucose metabolism and insulin activity in rat skeletal muscle cells by downregulating the expression of GLUT4 gene and protein and downregulating the protein expression of Grb2 and ERK2.
Guo
Q
Q
Department of Endocrinology, First Hospital Affiliated to Peking University, Beijing 100034, China.
Gao
Y
Y
Cong
L
L
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D051380:GRB2 Adaptor Protein; D051275:Glucose Transporter Type 4; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009124:Muscle Proteins; D018482:Muscle, Skeletal / Q000166:cytology*; D019301:Oleic Acid / Q000494:pharmacology*; D010168:Palmitates / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction
D048868:Adaptor Proteins, Signal Transducing; D051380:GRB2 Adaptor Protein; D051275:Glucose Transporter Type 4; C495950:Grb2 protein, rat; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D010168:Palmitates; D011506:Proteins; C495694:Slc2a4 protein, rat; D019301:Oleic Acid; D019950:Mitogen-Activated Protein Kinase 1