The effect of a cell-permeable diacylglycerol analogue on single Ca2+ (Ba2+) channel currents in the insulin-secreting cell line RINm5F.

Depolarization evokes opening of single Ca2+ (Ba2+) channels of the 'L' type in the insulin-secreting cell line RINm5F. Stimulation of the cells with the membrane-permeable diacylglycerol analogue didecanoylglycerol (DC10; 5 micrograms/ml) markedly enhanced the proportion of time the channels spent in the open state during depolarizing voltage pulses. Similar effects have previously been demonstrated with glyceraldehyde stimulation and it therefore seems possible that carbohydrate-evoked cellular Ca2+ uptake is mediated via protein kinase C activation.