Induction of intestinal glucose carriers in streptozocin-treated chronically diabetic rats.
The maximal transport capacity (Vmax) for intestinal glucose absorption is increased in experimentally induced chronic diabetes mellitus. Using [3H]phlorizin radioautography, we examined the relation between this increase in transport Vmax and the number and distribution of sodium-glucose co-transporters on the luminal surface of rat ileum. Male Lewis rats were made diabetic with streptozocin. Ninety days later we measured 3-O-methyl-D-glucopyranose absorption and specific [3H]phlorizin binding to the ileal mucosa of the same rats. Net 3-O-methyl-D-glucopyranose flux was 6.9-fold greater in diabetic rats compared with age-matched controls. Specific binding of [3H]phlorizin to the luminal surface was 7.2-fold greater in the diabetic rats. Radioautography revealed that, in chronic diabetes, specific phlorizin binding extends into the midvillus region of the ileum, whereas in age-matched controls, it is confined to villus tips. We believe that, in untreated diabetes, a larger fraction of intestinal villus epithelial cells participate in glucose absorption.
Fedorak
R N
RN
Department of Medicine, University of Alberta, Edmonton, Canada.
Gershon
M D
MD
Field
M
M
D019325:3-O-Methylglucose; D000818:Animals; D001345:Autoradiography; D001692:Biological Transport; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism* / Q000473:pathology; D005947:Glucose / Q000493:pharmacokinetics*; D007082:Ileum / Q000378:metabolism / Q000473:pathology; D007408:Intestinal Absorption; D008297:Male; D008757:Methylglucosides / Q000493:pharmacokinetics*; D008759:Methylglycosides / Q000493:pharmacokinetics*; D008871:Microvilli / Q000378:metabolism / Q000473:pathology; D010695:Phlorhizin / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D011917:Rats, Inbred Lew; D013311:Streptozocin
D008757:Methylglucosides; D008759:Methylglycosides; D019325:3-O-Methylglucose; D013311:Streptozocin; D010695:Phlorhizin; D005947:Glucose