Effects of cations, ionophores and hypoglycemic sulfonylureas on the fluorescence of fluorescein-labelled pancreatic islets
Deleers, M.; Lebrun, P.; Malaisse, W.J.
Research Communications in Chemical Pathology and Pharmacology 44(1): 83-92
1984
ISSN/ISBN: 0034-5164 PMID: 6427864 Document Number: 227979
The stimulation of Ca2+ inflow into rat pancreatic islet cells resulting from either an increase in extracellular K+ (from 5 to 37 mM) or Ca2+ (from 1 to 20 mM) concentration or the administration of tolbutamide, glibenclamide and the ionophores A23187 resulted in an apparent fall of cellular pH as judged from the fluorescence of islets prelabeled with fluorescein diacetate. The decrease in pH was abolished when the experiments were repeated in the absence of extracellular Ca2+. The cytosolic concentration of Ca2+ may affect the pH of islet cells, possibly by displacing H+ from intracellular binding sites.