Increase in CO3H- influx and cellular pH in glucose-stimulated pancreatic islets.

When rat islets are preincubated with fluorescein diacetate and examined in a spectrofluorometer, the intracellular pH rapidly increases by 0.21 pH units in response to a rise from 1.7-16.8 mM glucose. This coincides with a marked increase in 14CO3H- net uptake by the islets, suggesting that the glucose-induced increase in H+ generation rate is compensated for by stimulation of CO3H-/Cl- exchange.