Acute enterocyte adaptation to luminal glucose: a posttranslational mechanism for rapid apical recruitment of the transporter GLUT2. J Gastrointest Surg 2012 Feb;16(2):312-9; discussion 319
Date
11/10/2011Pubmed ID
22068967Pubmed Central ID
PMC3265642DOI
10.1007/s11605-011-1752-yScopus ID
2-s2.0-84856220815 (requires institutional sign-in at Scopus site) 34 CitationsAbstract
BACKGROUND: Glucose absorption postprandially increases markedly to levels far greater than possible by the classic glucose transporter sodium-glucose cotransporter 1 (SGLT1).
HYPOTHESIS: Luminal concentrations of glucose >50 mM lead to rapid, phenotypic, non-genomic adaptations by the enterocyte to recruit another transporter, glucose transporter 2 (GLUT2), to the apical membrane to increase glucose absorption.
METHODS: Isolated segments of jejunum were perfused in vivo with glucose-containing solutions in anesthetized rats. Carrier-mediated glucose uptake was measured in 10 and 100 mM glucose solutions (n = 6 rats each) with and without selective inhibitors of SGLT1 and GLUT2.
RESULTS: The mean rate of carrier-mediated glucose uptake increased in rats perfused with 100 mM versus 10 mM glucose to 13.9 ± 2.9 μmol from 2.1 ± 0.1 μmol, respectively (p < 0.0001). Using selective inhibitors, the relative contribution of GLUT2 to glucose absorption was 56% in the 100 mM concentration of glucose compared to the 10 mM concentration (27%; p < 0.01). Passive absorption accounted for 6% of total glucose absorption at 100 mM glucose.
CONCLUSION: A small amount of GLUT2 is active at the lesser luminal concentrations of glucose, but when exposed to concentrations of 100 mM, the enterocyte presumably changes its phenotype by recruiting GLUT2 apically to markedly augment glucose absorption.
Author List
Chaudhry RM, Scow JS, Madhavan S, Duenes JA, Sarr MGAuthor
Srivats Madhavan MBBS Assistant Professor in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adaptation, PhysiologicalAnimals
Blotting, Western
Enterocytes
Glucose
Glucose Transporter Type 2
Intestinal Absorption
Jejunum
Male
Phenotype
Random Allocation
Rats
Sodium-Glucose Transporter 1
Stereoisomerism
