Hindlimb perfusion induces GLUT-1 and immediate early gene expression in skeletal muscle

The purpose of the present study was to test the suitability of the rat hindlimb perfusion technique for studying the acute regulation of the GLUT-1 and GLUT-4 glucose transporter genes in adult skeletal muscle. To further examine the stability of the technique, we also monitored the transcription rate and mRNA content of selected immediate early genes. Nuclei and total RNA were isolated from red and white hindlimb muscle from perfused (2 h) and nonperfused control animals. Although GLUT-4 transcription and mRNA content remained stable, perfusion elicited a marked 3.5-fold increase in GLUT-1 mRNA in red and 2.2-fold increase in white skeletal muscle in the absence of any detectable change in transcription. In contrast to both GLUT-1 and GLUT-4, transcription originating from the c-fos and c-myc immediate early genes increased from 2.0- to 2.7-fold with perfusion in both red and white skeletal muscle, whereas transcription of the beta-actin gene decreased by 40-60%. Both c-fos and c-myc mRNA levels also increased with perfusion, whereas beta-actin mRNA remained unchanged. These findings clearly demonstrate that the current method of performing the hindlimb perfusion technique rapidly and dramatically alters the regulation of selected genes in skeletal muscle.