Fig. 10.

A: in elevated glucose, the α-cell is assumed to have g_KATPa on the left side of the schematic bell-shaped dose-response curve (○); insulin increases α-cell Ca²⁺ by increasing g_KATPa (●). B and C: in-phase insulin and somatostatin secretion. D and E: somatostatin suppresses glucagon secretion by a direct effect on exocytosis, which trumps the rise in Ca²⁺ so that glucagon is anti-phase with insulin. In this simulation, k_a = 0.0148, r_a = 5, ${\overline{\text{g}}}_{{\text{K}}_{\text{ATPb}}}$ = 7,000 pS, and g_KATPd = 0.26 nS. As insulin oscillates, g_KATPa varies between 0.04 and 0.08 nS (compare with Fig. 2A).