Glucose Cotransporter Activity Research Articles

Insulin regulates Na +/glucose cotransporter activity in rat small intestine

In order to examine the involvement of insulin in the activity of Na +/glucose cotransporter in rat small intestine, we compared Na +-dependent uptake of d-glucose by brush-border membrane vesicles prepared from control, streptozotocin-induced diabetic, insulin-treated diabetic and starved diabetic rats. In four groups, the uptake of d-glucose showed a transient overshoot in the presence of Na + gradient between medium and vesicles (medium > vesicles). The overshoot magnitude was increased (1.8-fold of controls) in diabetic brush border membrane vesicles and recovered to the control level by the treatment of diabetic rats with insulin. In contrast, increased uptake of d-glucose in diabetic rats was not recovered by the starvation of diabetic rats although the blood glucose level was the same as that of controls. Furthermore, we attempted to examine phlorizin binding activities among four groups. Scatchard analysis indicated that phlorizin binding to diabetic brush border membrane vesicles was increased (1.6-fold of controls) without a change of the affinity for phlorizin as compared with controls. Increased binding of phlorizin to diabetic brush border membrane vesicles was also recovered to the control level by the treatment of diabetic rats with insulin, but not by starvation. These results suggested that the increased activity of Na +/glucose cotransporter in diabetic rats was due to the increase of the number of cotransporter and that intestinal cotransporter was physiologically controlled by insulin, but not by blood glucose levels.

Changes in metabolite transport by small intestine and kidney of young and old rats

We have studied the influence of the ageing phenomenon on metabolite absorption by the small intestine and the kidney of the rat, using isolated brush-border membrane vesicles prepared from 2 groups, one composed of 2 month, and the other of 24 month, animals. “Overshoot”, which is typical of Na +-glucose cotransporter activity, disappeared in the duodenum and decreased in the kidney of the old rats. Short-circuiting of vesicles with valinomycin showed that, in the presence of K + and valinomycin, “overshoot” decreased in both groups by about the same percentage. The Na +-dependent uptake of aspartate and phenylalanine showed contrasting pictures in the jejunum and kidney of the aged animals: aspartate transport decreased only in the kidney, while phenylalanine uptake was negatively affected in the jejunum. Na +-dependent citrate uptake, studied in renal brush-border membrane vesicles, was lower in the old rats. The K m values determined for Na +-dependent d-glucose and citrate uptake in the kidney did not meaningfully differ between the two groups. A continuous decrease in Na +-dependent d-glucose and citrate uptake in the rat kidney, during ageing, was demonstrated.

Inhibition of the [formula omitted] cotransporter functional lysyl residues by 4-(4-methoxy-3-sulfophenyl)-2,6-bis(4-sulfophenyl)pyrylium

Pyrylium salts react exclusively with the ϵ-amino group of lysyl moieties and display a degree of selectivity exceeding all other known amino group reagents. This study represents the first use of a pyrylium salt in positively identifying the functional role of lysyl residues in a biologically active molecule, the Na + glucose cotransporter protein. We synthesized a hydrophilic pyrylium salt, 4-(4-methoxy-3-sulfophenyl)-2,6-bis(4-sulfophenyl)pyrylium perchlorate, which formed a stable pyridinium cation upon reaction with Nα-acetyl-L-lysine methyl ester. This pyrylium inhibited Na + glucose cotransporter activity in purified brush border membranes, in a concentration-dependent manner. The data unequivocally establish that critical lysyl residues are responsible for the activity of the membrane-bound glucose cotransporter protein.

Glucose transport during Ageing by human intestinal brush-border membrane vesicles

Glucose absorption by the small intestine is a complex phenomenon, that can be successfully studied by means of isolated brush-border and basolateral membrane vesicles of the enterocytes. We have carried out transport experiments on isolated brush-border membrane vesicles from the human small intestine, taking into account the age of the subjects. Our studies demonstrated that Na +-glucose co-transporter activity decreased as age increased with the “overshoot” phenomenon disappearing altogether in the oldest subjects. This effect was compared to that observed in intestinal membrane vesicles of young patients suffering from Crohn's disease; in this case there was a marked decrease in the Na +-dependent d-glucose uptake, but the “overshoot”, even though low, was present. K +-dependent d-glucose transport, diffusion of l-glucose and the levels of some enzyme markers for intestinal brush-border membranes were also studied.

Aboral changes in D-glucose transport by human intestinal brush-border membrane vesicles.

D-Glucose transport was investigated in isolated brush-border membrane vesicles from human small intestine. Characteristics of D-glucose transport from the jejunum were compared with that in the mid and terminal ileum. Jejunal and mid-ileal D-glucose transport was Na+-dependent and electrogenic. The transient overshoot of jejunal D-glucose transport was significantly greater than corresponding values in mid-ileum. The terminal ileum did not exhibit Na+-dependent D-glucose transport, but did exhibit Na+-dependent taurocholate transport. Na+-glucose co-transport activity as measured by tracer-exchange experiments was greatest in the jejunum, and diminished aborally. We conclude that D-glucose transport in man is Na+-dependent and electrogenic in the proximal intestine and directly related to the activity of D-glucose-Na+ transporters present in the brush-border membranes. D-Glucose transport in the terminal ileum resembles colonic transport of D-glucose.

Intestinal transport of 3-O-methyl-D-glucose in the normal and alloxan-diabetic rat.

ARTICLESIntestinal transport of 3-O-methyl-D-glucose in the normal and alloxan-diabetic ratP Flores, and HP SchedlP Flores, and HP SchedlPublished Online:01 Apr 1968https://doi.org/10.1152/ajplegacy.1968.214.4.725MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByThe effects of insulin on glucose and fluid transport in the isolated small intestine of normal ratsLife Sciences, Vol. 81, No. 1Alterations in intestinal morphology of streptozotocin-induced diabetic rats fed Jamaican bitter yam (Dioscorea polygonoides) steroidal sapogenin extractNutrition Research, Vol. 23, No. 11EFFECTS OF DIABETES ON CALCIUM UPTAKE BY RAT BRUSH BORDER MEMBRANE VESICLESClinical and Experimental Pharmacology and Physiology, Vol. 22, No. 4Experimental streptozotocin-induced diabetes and intestinal glucose metabolism in the rat, in vivo and in vitroActa Diabetologica, Vol. 32, No. 3Hypoglycaemic and antidiabetic effects in mice ofAloe arborescens Miller var.natalensis BergerPhytotherapy Research, Vol. 7, No. 7The role of insulin in the intestinal absorption of glucose in the ratInternational Journal of Biochemistry, Vol. 24, No. 4Variation of ileal taurocholate transport capacity in rats fed on high-fat diets and in alloxan-diabetic ratsNutrition Research, Vol. 11, No. 7Insulin regulates Na+/glucose cotransporter activity in rat small intestineBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 1063, No. 1Changes in amino acid and glucose transport in brush-border membrane vesicles of hyperglycemic guinea-pig small intestineBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 1063, No. 1Effect of chemically induced diabetes mellitus on glutamine transport in rat intestineGastroenterology, Vol. 98, No. 4Calcium Transport in the Streptozotocin Diabetic Rat: Studies with Brush Border Membrane VesiclesDecreased d-glucose transport across renal brush-border membrane vesicles from streptozotocin-induced diabetic ratsBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 1021, No. 2Induction of intestinal glucose carriers in streptozocin-treated chronically diabetic ratsGastroenterology, Vol. 96, No. 1Insulin and islet cell transplantation in streptozotocin-diabetic rats: Effect on intestinal uptake of hexosesComparative Biochemistry and Physiology Part A: Physiology, Vol. 82, No. 4Intestinal Permeability of Water-Soluble Nonelectrolytes: Sugars, Amino Acids, PeptidesStructural features of the rat small intestinal microvillus membrane in acute experimental diabetesDigestive Diseases and Sciences, Vol. 27, No. 9Augmented Release of Gastric Inhibitory Polypeptide into the Portal Vein in Response to Intraduodenal Glucose and Amino Acids in Anesthetized Rats Treated with Methylprednisolone or Alloxan19 February 2010 | Scandinavian Journal of Gastroenterology, Vol. 17, No. 3Hyperglycemia and net transintestinal glucose and sodium transport in the ratPfl�gers Archiv European Journal of Physiology, Vol. 390, No. 2Unidirectional flux rate of cholesterol and fatty acids into the intestine of rats with drug-induced diabetes mellitus: effect of variations in the effective resistance of the unstirred water layer and the bile acid micelle.Journal of Lipid Research, Vol. 21, No. 6Alterations in islet cell ultrastructure following streptozotocin-induced diabetes in the ratActa Diabetologica Latina, Vol. 17, No. 3-4Transport of monosaccharides by the small intestine of genetically diabetic miceGastroenterology, Vol. 78, No. 3Effect of food intake on intestinal absorption and mucosal hydrolases in alloxan diabetic ratsMetabolism, Vol. 29, No. 2Effects of diet, energy restriction and diabetes on hexose transport in the rat9 December 2008 | British Journal of Nutrition, Vol. 41, No. 3Induction of an intestinal epithelial sugar transport system by high blood sugarExperientia, Vol. 33, No. 2Intestinal digestion and absorption of sucrose in experimental diabetesActa Diabetologica Latina, Vol. 13, No. 3-4Effect of chronic glucagon-administration on the digestive and absorptive function of rat small intestine in vivoResearch In Experimental Medicine, Vol. 167, No. 1In vitro Behaviour of Human Jejunum and Ileum: Response to Theophylline and Acetyl cholineSugar transport in the small intestine of obese hyperglycemic, fed and fasted miceDiabetologia, Vol. 11, No. 5Jejunal sodium transport in the rat: Effects of alloxan diabetesBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 367, No. 2Untersuchungen zum Einfluß des Insulins auf die intestinale Resorption beim MenschenResearch in Experimental Medicine, Vol. 161, No. 4Untersuchungen zum Einfluß von Glucagon und Insulin auf die Glucoseresorption beim MenschenSugar and electrolyte absorption in the rat intestine perfused ?in vivo?Pfl�gers Archiv European Journal of Physiology, Vol. 340, No. 4Increase of intestinal brush border hydrolases in mucosa of streptozotocin-diabetic ratsDiabetologia, Vol. 8, No. 6Untersuchungen zum Einfluß von Insulin auf die Glucoseresorption beim MenschenEffects of diabetes on intestinal growth in the ratJournal of Experimental Zoology, Vol. 176, No. 4Carbohydrate Digestion and AbsorptionGastroenterology, Vol. 58, No. 1 More from this issue > Volume 214Issue 4April 1968Pages 725-729 Copyright & PermissionsCopyright © 1968 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1968.214.4.725PubMed5642932History Published online 1 April 1968 Published in print 1 April 1968 Metrics