Beta cell contact and insulin release.

Insulin secretion by intact islets, dispersed islet cells and dispersed cells allowed to reaggregate was compared in perifusion. Although single cells and aggregates showed basal insulin secretion and a prompt response to glucose challenge, basal secretion, peak insulin secretion and total insulin secretion during a 60 minute stimulation were profoundly less than those activities of intact islets. These results suggest that dispersed beta cells are responsive to glucose as a secretagogue, but the magnitude of the response is greatly diminished and not restored by simple cell contact.