aston-highglucose-2005.pdf (162.5 kB)
Download file

High glucose-induced impairment in insulin secretion is associated with reduction in islet glucokinase in a mouse model of susceptibility to islet dysfunction

Download (162.5 kB)
journal contribution
posted on 01.08.2005, 00:00 authored by S Kooptiwut, M Kebede, S Zraika, S Visinoni, Kathryn Aston-MourneyKathryn Aston-Mourney, J Favaloro, C Tikellis, M Thomas, J Forbes, M Cooper, M Dunlop, J Proietto, S Andrikopoulos
Type 2 diabetes is characterized by islet dysfunction resulting in hyperglycemia, which can then lead to further deterioration in islet function. A possible mechanism for hyperglycemia-induced islet dysfunction is the accumulation of advanced glycation end products (AGE). The DBA/2 mouse develops pancreatic islet dysfunction when exposed to a high glucose environment and/or obesity-induced insulin resistance. To determine the biochemical cause of dysfunction, DBA/2 and C57BL/6 control islets were incubated in 11.1 mM or 40 mM glucose in the absence or presence of the AGE inhibitor aminoguanidine (AG) for 10 days. Basal (2.8 mM glucose) insulin release was increased in both DBA/2 and C57BL/6 islets incubated with 40 mM vs 11.1 mM glucose for 10 days. Chronic exposure to hyperglycemia decreased glucose (20 mM)-stimulated insulin secretion in DBA/2 but not in C57BL/6 islets. AG significantly increased fold-induced insulin release in high glucose cultured DBA/2 mouse islets, but did not affect C57BL/6 islet function. DBA/2 islet glucokinase was significantly reduced following 40 mM glucose culture, compared with 11.1 mM glucose cultured DBA/2 islets and 40 mM glucose cultured C57BL/6 islets. Incubation of islets with AG resulted in a normalization of DBA/2 islet glucokinase levels. In conclusion, chronic high glucose-induced increases in AGE can result in islet dysfunction and this is associated with reduced glucokinase levels in a mouse model with susceptibility to islet failure.

History

Journal

Journal of molecular endocrinology

Volume

35

Issue

1

Pagination

39 - 48

Publisher

BioScientifica

Location

Bristol, England

ISSN

0952-5041

eISSN

1479-6813

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2005, BioScientifica