| First Author | Liu ML | Year | 1993 |
| Journal | Proc Natl Acad Sci U S A | Volume | 90 |
| Issue | 23 | Pages | 11346-50 |
| PubMed ID | 8248251 | Mgi Jnum | J:278490 |
| Mgi Id | MGI:6315244 | Doi | 10.1073/pnas.90.23.11346 |
| Citation | Liu ML, et al. (1993) Transgenic mice expressing the human GLUT4/muscle-fat facilitative glucose transporter protein exhibit efficient glycemic control. Proc Natl Acad Sci U S A 90(23):11346-50 |
| abstractText | To examine the physiological role of the GLUT4/muscle-fat specific facilitative glucose transporter in regulating glucose homeostasis, we have generated transgenic mice expressing high levels of this protein in an appropriate tissue-specific manner. Examination of two independent founder lines demonstrated that high-level expression of GLUT4 protein resulted in a marked reduction of fasting glucose levels (approximately 70 mg/dl) compared to wild-type mice (approximately 130 mg/dl). Surprisingly, 30 min following an oral glucose challenge the GLUT4 transgenic mice had only a slight elevation in plasma glucose levels (approximately 90 mg/dl), whereas wild-type mice displayed a typical 2- to 3-fold increase (approximately 250-300 mg/dl). In parallel to the changes in plasma glucose, insulin levels were approximately 2-fold lower in the transgenic mice compared to the wild-type mice. Furthermore, isolated adipocytes from the GLUT4 transgenic mice had increased basal glucose uptake and subcellular fractionation indicated elevated levels of cell surface-associated GLUT4 protein. Consistent with these results, in situ immunocytochemical localization of GLUT4 protein in adipocytes and cardiac myocytes indicated a marked increase in plasma membrane-associated GLUT4 protein in the basal state. Taken together these data demonstrate that increased expression of the human GLUT4 gene in vivo results in a constitutively high level of cell surface GLUT4 protein expression and more efficient metabolic control over fluctuations in plasma glucose concentrations. |
