Figure 3.

Effects of high glucose on intracellular calcium. (A) Intracellular calcium was measured in islets exposed to the increasing glucose conditions noted by the horizontal bars. Calcium levels increased sharply from 3 mM to 24 mM glucose but did not increase further when exposed to 84 mM glucose. Average calcium levels from 23 islets were calculated from the 15–20- and 30–35 min time points and showed no significant difference. (B) Intracellular calcium was measured in islets exposed to the increasing glucose conditions and tolbutamide noted by the horizontal bars. Calcium levels increased sharply from 3 mM to 24 mM but did not increase further when exposed to 24 mM glucose combined with 250 μM tolbutamide. Average calcium levels from 23 islets were calculated from the 15–20 and 30–35 min time points and showed no significant difference. *** p < 0.001 difference between 3 and 24 mM glucose.