Perturbation of pancreatic islet function in glucose-infused rats.
The secretory behavior of insulin- and glucagon-producing cells was found to be perturbed in isolated perfused pancreases removed from rats infused with hypertonic solutions of glucose for 48 hours. The anomalies included a high basal release of insulin and a paradoxical increase in insulin output and decrease in glucagon release in response to a fall in D-glucose concentration. Likewise, in isolated islets prepared from the glucose-infused rats, L-arginine or theophylline stimulated insulin release at a low ambient concentration of D-glucose, at variance with the situation found in islets removed from normal rats. These secretory perturbations could not be attributed to any obvious defect in either the transport of D-glucose into islet cells or its further utilization and oxidation, but coincided with the abnormal accumulation of glycogen in the B-cell. It is proposed that the latter anomaly may play a role in the altered dynamics of insulin release found in animals or patients with long-term hyperglycemia.
Laboratory of Experimental Medicine, Brussels Free University, Belgium.
G
G
Marynissen
V
V
Leclercq-Meyer
A
A
Sener
W J
WJ
Malaisse
D000818:Animals; D001120:Arginine / Q000008:administration & dosage; D001692:Biological Transport / Q000187:drug effects; D001786:Blood Glucose / Q000032:analysis; D002118:Calcium / Q000378:metabolism; D005934:Glucagon / Q000378:metabolism; D005947:Glucose / Q000008:administration & dosage* / Q000494:pharmacology; D007262:Infusions, Intravenous; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D008954:Models, Biological; D010477:Perfusion; D051381:Rats; D013806:Theophylline / Q000008:administration & dosage
D001786:Blood Glucose; D007328:Insulin; D005934:Glucagon; D001120:Arginine; D013806:Theophylline; D005947:Glucose; D002118:Calcium