Figure 8.

(A) Model simulation in which the membrane potential is clamped with diazoxide (Dz) and elevated KCl. Glucose concentration is increased at the arrows, from $G=5\text{mM}$ to 9 $\text{mM}$, from 9 $\text{mM}$ to 11 $\text{mM}$, and finally to 13 $\text{mM}$. The width of each arrow indicates the size of the glucose concentration. (B and C) Two experiments in which islets were exposed to Dz (200 μM) and KCl (30 mM) and in which glucose was increased from 5 mM to higher levels, as indicated, before being returned to 5 mM. Each trace corresponds to an islet and is representative of the protocol applied to 21 islets isolated from two different Swiss-Webster mice from six different sets of recording sessions. During the time interval where glucose concentrations were increased, we observed a significant positive slope in ratio versus time (slope = 0.0021 min⁻¹; p-value < 0.001). To see this figure in color, go online.