In mammals, GLUT2 plays an essential role in glucose homeostasis. From an evolutionary perspective, relatively little is known about the biology of GLUT2, or other GLUTs, in nonmammalian vertebrates. Here, we have conducted studies to functionally characterize GLUT2 in zebrafish. First, we cloned the zebrafish ortholog of GLUT2 (zfGLUT2) encoding a protein of 504 amino acids with high-sequence ...

We previously reported that pancreatic islet beta-cells from GLUT2-null mice lost the first phase but preserved the second phase of glucose-stimulated insulin secretion (GSIS). Furthermore, we showed that the remaining secretory activity required glucose uptake and metabolism because it can be blocked by inhibition of oxidative phosphorylation. Here, we extend these previous studies by analyzin...

Many researchers in the last couple of decades have suggested that glucose absorption small intestine depends on both constitutively expressed SGLT1 and translocated GLUT2 brush border membrane, especially presence a high concentration luminal glucose. Afshar et al. generated computational model non-isotonic uptake by intestinal epithelial cells. The incorporates apical via GLUT2, basolateral e...

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 secr...

This study compared the ability of nine culinary plant extracts containing a wide array of phytochemicals to inhibit fructose uptake and then explored the involvement of intestinal fructose transporters and phytochemicals for selected samples. The chemical signature was characterized by high performance liquid chromatography with mass spectrometry. Inhibition of [(14)C]-fructose uptake was test...

Glucose is a key modulator of feeding behavior. By acting in peripheral tissues and in the central nervous system, it directly controls the secretion of hormones and neuropeptides and modulates the activity of the autonomic nervous system. GLUT2 is required for several glucoregulatory responses in the brain, including feeding behavior, and is localized in the hypothalamus and brainstem, which a...

Intestinal hexose absorption and gluconeogenesis have been studied in relation to refeeding after two different fasting phases: a long period of protein sparing during which energy expenditure is derived from lipid oxidation (phase II), and a later phase characterized by a rise in plasma corticosterone triggering protein catabolism (phase III). Such a switch in body fuel uses, leading to change...

AMPK (AMP-activated protein kinase) is a key sensor of energy status within the cell. Activated by an increase in the AMP/ATP ratio, AMPK acts to limit cellular energy depletion by down-regulating selective ATP-dependent processes. The purpose of the present study was to determine the role of AMPK in regulating intestinal glucose transport. [3H]3-O-methyl glucose fluxes were measured in murine ...

Glucose is reabsorbed from the glomerular filtrate in the proximal segment of the renal tubule in two stages. The first stage is uphill transport across the brush border membrane by Na-glucose cotransport and the second stage is downhill transport across the basolateral membrane by facilitated diffusion. Genes for both a renal Na-glucose cotransporter (SGLT1) and a renal facilitated glucose tra...

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are incretins secreted in response to oral glucose ingestion by intestinal L and K cells, respectively. The molecular mechanisms responsible for intestinal cell glucose sensing are unknown but could be related to those described for beta-cells, brain and hepatoportal sensors. We determined the role of GLUT2, ...