title: Relationship between erythrocyte GLUT1 function and membrane glycation in type 2 diabetes.
abstract: This paper investigates the effect of glycation on glucose transport in erythrocytes. Glucose transporter function, numbers and erythrocyte phosphorylation rates are simultaneously studied using 30 Caucasian patients with diabetes and 30 Caucasian control volunteers (mean +/- SD where P < or = 0.05; age 48 +/- 8 vs. 45 +/- 8 years [ns]; body mass index [BMI] 31 +/- 7 vs. 27 +/- 5 [P=0.035]; blood glucose 12 +/- 7 vs. 5 +/- 0.6 mmol/L [P=0.001]; HbA1c 8 +/- 2 vs. 5 +/- 0.3% [P=0.0001]; fructosamine 336 +/- 64 vs. 237 +/- 16 micromol/L [P=0.0001]; disease duration 13 +/- 11 years, respectively). Significant differences were found for glucose transporter function, with 3-O-methylglucose uptake rates (108 +/- 49 vs. 146 +/- 55 micromol/L/sec/10(12) cells [P=0.010]); D-glucose influx (64 +/- 30 vs. 117 +/- 45 micromol/L/sec/10(12) cells [P=0.0001]); and D-glucose net transport (31 +/- 22 vs. 74 +/- 55 micromol/L/sec/ 10(12) cells [P = 0.0001]). No differences were found for phosphorylation rates using 2-deoxyglucose (33 +/- 17 vs. 38 +/- 12 micromol/L/sec/10(12) cells [P=0.194]). The number of functional transporters using cytochalasin B studies measured via B(max), was not found to be significantly different between the groups (195 +/- 139 vs. 264 +/- 174 [P=0.206]). However, K(d) was lower for those with diabetes, suggesting higher binding affinity (12 +/- 11 vs. 32 +/- 25 nmol/L [P=0.006]). A negative correlation between HbAlc and D-glucose influx involving both groups was found (r=-0.670, P=0.0001). Glucose transport is shown to be decreased in people who have diabetes compared to normoglycaemic volunteers, whereas the number of glucose transporters is apparently unchanged; however, affinity for binding is increased.
authors.affiliation: School of Health Sciences, University of Wolverhampton, Wolverhampton, UK.
authors.forename: M M
authors.initials: MM
authors.lastname: Porter-Turner
authors.forename: J C
authors.initials: JC
authors.lastname: Skidmore
authors.forename: M A
authors.initials: MA
authors.lastname: Khokher
authors.forename: B M
authors.initials: BM
authors.lastname: Singh
authors.forename: C A
authors.initials: CA
authors.lastname: Rea
mesh_terms: D000328:Adult; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003571:Cytochalasin B / Q000378:metabolism / Q000494:pharmacology; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005947:Glucose / Q000493:pharmacokinetics*; D051272:Glucose Transporter Type 1 / Q000378:metabolism*; D006031:Glycosylation / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged
chemical_list: D051272:Glucose Transporter Type 1; C495677:SLC2A1 protein, human; D003571:Cytochalasin B; D005947:Glucose