Figure 9.

Mathematical model of P/Q‐type Ca²⁺ inhibition in human α‐cells. (A) Mathematical model of membrane potential in a human α‐cell. The model was simulated under low glucose conditions . The P/Q‐type Ca²⁺ current was then reduced , mimicking GLP‐1 application (Fig. 7B). The K_ATP current was then increased , to mimic the action of diazoxide (Fig. 6). (B) The influence of the different simulation conditions on action potential height. P/Q‐type inhibition reduces action potential height , and this is restored by increasing the K_ATP current . The below traces show the transmembrane K⁺ (red), Na⁺ (green), and Ca²⁺ (blue) currents (I_K, I_{N a} and I_{C a}, respectively) underlying the action potential. These simulation data explain why diazoxide can restore glucagon secretion in the presence of GLP‐1.