The secretory deficit in islets from db/db mice is mainly due to a loss of responding beta cells.

ABSTRACT:

Aims/hypothesis

We used the db/db mouse to determine the nature of the secretory defect in intact islets.

Methods

Glucose tolerance was compared in db/db and wild-type (WT) mice. Isolated islets were used: to measure insulin secretion and calcium in a two-photon assay of single-insulin-granule fusion; and for immunofluorescence of soluble N-ethylmaleimide-sensitive factor attachment proteins (SNAREs).

Results

The 13-18-week-old db/db mice showed a diabetic phenotype. Isolated db/db islets showed a 77% reduction in insulin secretion induced by 15 mmol/l glucose and reductions in the amplitude and rise-time of the calcium response to glucose. Ionomycin-induced insulin secretion in WT but not db/db islets. Immunofluorescence showed an increase in the levels of the SNAREs

SUBMITTER: Do OH 

PROVIDER: S-EPMC4052007 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature