The role of SGLT1 and GLUT2 in intestinal glucose transport and sensing
| Autor: | Hannelore Daniel, Kerstin E. Geillinger, Tamara Zietek, Bernard Thorens, Pia V. Röder, Hermann Koepsell |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Blood Glucose
Anatomy and Physiology Mouse Glucose uptake Digestive Physiology lcsh:Medicine Biochemistry Intestinal absorption Digestive Anatomy Transmembrane Transport Proteins Mice 0302 clinical medicine Insulin Secretion Insulin Sodium-Glucose Transporter 1 Intestinal Mucosa lcsh:Science Glucose Transporter Type 2 2. Zero hunger 0303 health sciences Multidisciplinary digestive oral and skin physiology Animal Models ddc Intestines Carbohydrate Metabolism Research Article Nutrient and Storage Proteins medicine.medical_specialty endocrine system Incretin Blood sugar Endocrine System 030209 endocrinology & metabolism Biology Incretins 03 medical and health sciences Model Organisms Internal medicine ddc:570 medicine Animals 030304 developmental biology Digestive Functions Endocrine Physiology lcsh:R Glucose transporter Proteins Apical membrane Hormones Glucose Metabolism Endocrinology Intestinal Absorption biology.protein GLUT2 lcsh:Q Endocrine Cells Digestive System |
| Zdroj: | PLoS One, vol. 9, no. 2, pp. e89977 PLoS ONE PLoS ONE, Vol 9, Iss 2, p e89977 (2014) |
| Popis: | Intestinal glucose absorption is mediated by SGLT1 whereas GLUT2 is considered to provide basolateral exit. Recently it was proposed that GLUT2 can be recruited into the apical membrane after a high luminal glucose bolus allowing bulk absorption of glucose by facilitated diffusion. Moreover SGLT1 and GLUT2 are suggested to play an important role in intestinal glucose sensing and incretin secretion. In mice that lack either SGLT1 or GLUT2 we re assessed the role of these transporters in intestinal glucose uptake after radiotracer glucose gavage and performed Western blot analysis for transporter abundance in apical membrane fractions in a comparative approach. Moreover we examined the contribution of these transporters to glucose induced changes in plasma GIP GLP 1 and insulin levels. In mice lacking SGLT1 tissue retention of tracer glucose was drastically reduced throughout the entire small intestine whereas GLUT2 deficient animals exhibited higher tracer contents in tissue samples than wild type animals. Deletion of SGLT1 resulted also in reduced blood glucose elevations and abolished GIP and GLP 1 secretion in response to glucose. In mice lacking GLUT2 glucose induced insulin but not incretin secretion was impaired. Western blot analysis revealed unchanged protein levels of SGLT1 after glucose gavage. GLUT2 detected in apical membrane fractions mainly resulted from contamination with basolateral membranes but did not change in density after glucose administration. SGLT1 is unequivocally the prime intestinal glucose transporter even at high luminal glucose concentrations. Moreover SGLT1 mediates glucose induced incretin secretion. Our studies do not provide evidence for GLUT2 playing any role in either apical glucose influx or incretin secretion. © 2014 Röder et al. |
| Databáze: | OpenAIRE |
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