Glucose-stimulated insulin secretion (GSIS)
The islets were seeded and pretreated in high glucose/STZ with/without
OGT2115 for 24 h. The islets were then rinsed and incubated for 1 h at
37°C in Krebs-Ringer bicarbonate (115 mM NaCl, 24 mM
NaHCO3, 5 mM KCl, 2.5 mM CaCl2, 1 mM
MgCl2, 10 mM HEPES, and 0.2% bovine serum albumin, pH
=7.2) containing 5 mM or 25 mM glucose. After incubation,
the supernatant
was collected and the concentration of insulin was measured with a
radioimmunoassay (RIA) kit (Beijing North Institute of Biological
Technology, Beijing, China).