Cholinergic stimulation of insulin release from cloned B-cell lines HIT-T15 and RINm5F.

Acetylcholine stimulated the release of insulin from cultured HIT-T15 and RINm5F cells in the absence of glucose confirming that the insulin response to cholinergic stimulation is preserved in these two cloned B-cell lines. In addition acetylcholine potentiated glucose stimulated insulin release from HIT-T15 but not from RINm5F cells. Perifused HIT-T15 cells responded to square wave acetylcholine challenge with a monophasic release of insulin while the release profile for RINm5F cells was irregular and reduced. Acetylcholine stimulated insulin release from both cell lines was reduced by atropine but unaffected by hexamethonium confirming a mechanism of action involving muscarinic receptor activation.