TY  - JOUR
A1  - Koepsell, Hermann
T1  - Glucose transporters in the small intestine in health and disease
JF  - Pflügers Archiv - European Journal of Physiology
N2  - Absorption of monosaccharides is mainly mediated by Na\(^+\)-d-glucose cotransporter SGLT1 and the facititative transporters GLUT2 and GLUT5. SGLT1 and GLUT2 are relevant for absorption of d-glucose and d-galactose while GLUT5 is relevant for d-fructose absorption. SGLT1 and GLUT5 are constantly localized in the brush border membrane (BBM) of enterocytes, whereas GLUT2 is localized in the basolateral membrane (BLM) or the BBM plus BLM at low and high luminal d-glucose concentrations, respectively. At high luminal d-glucose, the abundance SGLT1 in the BBM is increased. Hence, d-glucose absorption at low luminal glucose is mediated via SGLT1 in the BBM and GLUT2 in the BLM whereas high-capacity d-glucose absorption at high luminal glucose is mediated by SGLT1 plus GLUT2 in the BBM and GLUT2 in the BLM. The review describes functions and regulations of SGLT1, GLUT2, and GLUT5 in the small intestine including diurnal variations and carbohydrate-dependent regulations. Also, the roles of SGLT1 and GLUT2 for secretion of enterohormones are discussed. Furthermore, diseases are described that are caused by malfunctions of small intestinal monosaccharide transporters, such as glucose-galactose malabsorption, Fanconi syndrome, and fructose intolerance. Moreover, it is reported how diabetes, small intestinal inflammation, parental nutrition, bariatric surgery, and metformin treatment affect expression of monosaccharide transporters in the small intestine. Finally, food components that decrease d-glucose absorption and drugs in development that inhibit or downregulate SGLT1 in the small intestine are compiled. Models for regulations and combined functions of glucose transporters, and for interplay between d-fructose transport and metabolism, are discussed.
KW  - glucose transporter
KW  - small intestine
KW  - regulation
KW  - SGLT1
KW  - GLUT2
KW  - GLUT5
KW  - glucose-galactose malabsorption
KW  - fructose intolerance
KW  - diabetes
KW  - bariatric surgery
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232552
SN  - 0031-6768
VL  - 472
ER  - 
TY  - JOUR
A1  - Jurowich, Christian Ferdinand
A1  - Otto, Christoph
A1  - Rikkala, Prashanth Reddy
A1  - Wagner, Nicole
A1  - Vrhovac, Ivana
A1  - Sabolić, Ivan
A1  - Germer, Christoph-Thomas
A1  - Koepsell, Hermann
T1  - Ileal interposition in rats with experimental type 2 like diabetes improves glycemic control independently of glucose absorption
JF  - Journal of Diabetes Research
N2  - Bariatric operations in obese patients with type 2 diabetes often improve diabetes before weight loss is observed. In patients mainly Roux-en-Y-gastric bypass with partial stomach resection is performed. Duodenojejunal bypass (DJB) and ileal interposition (IIP) are employed in animal experiments. Due to increased glucose exposition of L-cells located in distal ileum, all bariatric surgery procedures lead to higher secretion of antidiabetic glucagon like peptide-1 (GLP-1) after glucose gavage. After DJB also downregulation of Na\(^{+}\)-D-glucose cotransporter SGLT1 was observed. This suggested a direct contribution of decreased glucose absorption to the antidiabetic effect of bariatric surgery. To investigate whether glucose absorption is also decreased after IIP, we induced diabetes with decreased glucose tolerance and insulin sensitivity in male rats and investigated effects of IIP on diabetes and SGLT1. After IIP, we observed weight-independent improvement of glucose tolerance, increased insulin sensitivity, and increased plasma GLP-1 after glucose gavage. The interposed ileum was increased in diameter and showed increased length of villi, hyperplasia of the epithelial layer, and increased number of L-cells. The amount of SGLT1-mediated glucose uptake in interposed ileum was increased 2-fold reaching the same level as in jejunum. Thus, improvement of glycemic control by bariatric surgery does not require decreased glucose absorption.
KW  - glucagon like peptide-1
KW  - food intake
KW  - body weight
KW  - cotransporter SGLT1
KW  - bariatric surgery
KW  - biliopancreatic diversion
KW  - intestinal glucose
KW  - gut hormones
KW  - duodenal jejunal bypass
KW  - Y-gastric bypass
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149166
VL  - 2015
IS  - 490365
ER  -