Effect of Glucose and 3-<i>O</i>-Methylglucose on [Ca²⁺]_c Measured by Fluo-8.

<p>A: Fluo-8-loaded cells were stimulated by 25 mM glucose and changes in [Ca^<b>2+</b>]_c were measured. A typical response with a rapid peak is presented. The trace is a respresentative of those-obtained in more than 100 cells. B: Fluo-8-loaded cells were incubated in Ca^<b>2+</b>-free HBSS and stimulated by 25 mM glucose as shown by the arrow. The trace is a representative of those obtained in more than 100 cells. C: Fluo-8-loaded cells were stimulated by 25 mM glucose in the presence of 1 μM nifedipine, which was added 10 min pror to the stimulation by glucose. Changes in [Ca^<b>2+</b>]_c were monitored. The trace is a representative of those obtained in more than 100 cells. D: Fluo-8-loaded cells preincubated for 10 min with 10 mM mannoheptulose were stimulated with 25 mM glucose as indicated by the arrow. The trace is a representative of those obtained in more than 100 cells. E: Fluo-8-loaded cells were stimulated by 25 mM 3-<i>O</i>-methylglucose and changes in [Ca^<b>2+</b>]_c were monitored. The trace is a representative of those obtained in more than 100 cells. F: Fluo-8-loaded cells were stimulated by 25 mM glucose in the presence of 5 mM lactisole, which was added 10 min prior to the stimulation by glucose. Changes in [Ca^<b>2+</b>]_c were monitored. The trace is a representative of those obtained in more than 100 cells. G: Experiments were carried out as shown in F and AUC from 1 to 5 min was calculated. Values are the mean ± SE for 10 determinations.