| First Author | Dumke CL | Year | 2001 |
| Journal | Horm Metab Res | Volume | 33 |
| Issue | 12 | Pages | 696-700 |
| PubMed ID | 11753753 | Mgi Jnum | J:120555 |
| Mgi Id | MGI:3706758 | Doi | 10.1055/s-2001-19141 |
| Citation | Dumke CL, et al. (2001) Absence of insulin receptor substrate-1 expression does not alter GLUT1 or GLUT4 abundance or contraction-stimulated glucose uptake by mouse skeletal muscle. Horm Metab Res 33(12):696-700 |
| abstractText | The purpose of this study was to determine the influence of insulin receptor substrate-1 (IRS-1) expression on GLUT1 and GLUT4 glucose transporter protein abundance, contraction-stimulated glucose uptake, and contraction-induced glycogen depletion by skeletal muscle. Mice (6 months old) from three genotypes were studied: wild-type (IRS-1(+/+)), heterozygous (IRS-1(+/-)) for the null allele, and IRS-1 knockouts (IRS-1(-/-)) lacking a functional IRS-1 gene. In situ muscle contraction was induced (electrical stimulation of sciatic nerve) in one hindlimb using contralateral muscles as controls. Soleus and extensor digitorum longus were dissected and 2-deoxyglucose uptake was measured in vitro. 2-Deoxyglucose uptake was higher in basal muscles (no contractions) from IRS-1(-/-) vs. both other genotypes. Contraction-stimulated 2-deoxyglucose uptake and glycogen depletion did not differ among genotypes. Muscle IRS-1 protein was undetectable for IRS-1(-/-) mice, and values were approximately 40 % lower in IRS-1(+/-) than in IRS-1(+/+) mice. No difference was found in IRS-1(+/+) compared to IRS-1(-/-) groups regarding muscle abundance of GLUT1 and GLUT4. Substantial reduction or elimination of IRS-1 did not alter the hallmark effects of contractions on muscle carbohydrate metabolism--activation of glucose uptake and glycogen depletion. |
