1992 Volume 35 Issue 9 Pages 747-753
Glucose-stimulated insulin release is believed to be mediated by an increase in cytoplasmic free Ca2+ ([Ca2+] i). Previous exposure to high glucose concentrations decreases the subsequent glucose stimulated insulin release. To reveal the mechanism of this, we studied the effects of previous exposure to high glucose concentrations on glucose-stimulated insulin release and on glucose-stimulated [Ca2+] i response, using rat pancreatic islets.
Glucose stimulated insulin release from pancreatic islets in perfusion and perifusion systems. Previous exposure to high glucose concentrations in rat pancreatic islets in vivo and in vitro decreased the subsequent glucose-stimulated insulin release. We also studied the glucose-stimulated [Ca2+] i response, using fura-2. Glucose induced [Ca2+] i response. Previous exposure to high glucose concentrations also decreased this glucose-stimulated [Ca2+] i response. Previous exposure to high glucose concentrations decreased both the glucose-stimulated [Ca2+] i response and insulin release, suggesting that impaired glucose-stimulated [Ca2+] i response may be associated with impaired glucose-stimulated insulin release.
