Effects of glucose on [Ca2+]c changes in αTC1-9 cells. A: The glucose concentration (G) was either decreased or increased from 20 to 0 mmol/l as indicated. B: Quantification of changes in [Ca2+]c oscillation frequency of the experiments above. The dashed line illustrates the frequency, expressed as 100%, measured at
20 mmol/l glucose from 10 to 20 min in each experiment, whereas the empty bars (□) illustrate the frequency at 0, 1, 3, 5,
or 10 mmol/l glucose during the first 10 min of perifusion. Values are the means ± SE for 18–52 cells from 9 to 15 independent
experiments. *P < 0.05 for the effects of glucose.