title: Glucose regulates both glucose transport and the glucose transporter gene expression in a hamster-derived pancreatic beta-cell line (HIT).
abstract: We studied the effect of chronic exposure to high glucose on the glucose transport regulation in hamster pancreatic Beta cells in permanent culture (HIT). Cells were exposed to either 5.5 mmol/l or 16.7 mmol/l glucose for 48 h and then glucose transport was studied by measuring the (3H)-2-deoxyglucose uptake for 5 and 10 min at 37 degrees C. The 2-deoxyglucose uptake was lower in cells pre-exposed to glucose 16.7 mmol/l for 48 h compared to cells pre-exposed to 5.5 (12.0 +/- 1.6 vs 19.1 +/- 1.2 nmol/0.1 mg after 5 min, and 22.2 +/- 2.6 vs 39.0 +/- 2.9 after 10 min respectively, mean +/- SEM, n = 5, p less than 0.01). In order to investigate the mechanism(s) for glucose impairment of glucose transport, we studied the glucose carrier gene expression in the same cells by Northern and slot-blot analysis. When total RNA was extracted from HIT cells cultured at either 5.5 or 16.7 mmol/l glucose and then hybridized to 32P-labelled cDNA probes for the glucose transporter 1, the glucose transporter 2 and beta-actin, a significant reduction of both glucose transporter 1 (-63.9 +/- 4.1%, mean +/- SEM, n = 3) and glucose transporter 2 (-48.9 +/- 3.2%) mRNA was observed in HIT cells cultured with high glucose. In the same experiments no change of beta-actin mRNA was observed, suggesting that the effect of high glucose was specific on the glucose-transporter mRNAs.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Cattedra di Endocrinologia, University of Catania Medical School, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Purrello
authors.forename: M
authors.initials: M
authors.lastname: Buscema
authors.forename: M
authors.initials: M
authors.lastname: Vetri
authors.forename: C
authors.initials: C
authors.lastname: Vinci
authors.forename: C
authors.initials: C
authors.lastname: Gatta
authors.forename: F
authors.initials: F
authors.lastname: Forte
authors.forename: A M
authors.initials: AM
authors.lastname: Rabuazzo
authors.forename: R
authors.initials: R
authors.lastname: Vigneri
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D015152:Blotting, Northern; D002460:Cell Line; D006224:Cricetinae; D015342:DNA Probes; D003847:Deoxyglucose / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D009004:Monosaccharide Transport Proteins / Q000235:genetics*; D012313:RNA / Q000235:genetics / Q000302:isolation & purification
chemical_list: D015342:DNA Probes; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D012313:RNA; D003847:Deoxyglucose; D005947:Glucose