Figure 4.

The effect of decreasing extracellular Ca²⁺, the addition of L-type Ca²⁺ channel blockers, diazoxide, or wortmannin on the insulin-stimulated increase in [Ca²⁺]_mem. Insulin was present in all experiments at 10 milliunits/ml. Unless noted otherwise, extracellular calcium was 1.8 mM. Values are means ± SEM, and the number of observations is shown in parentheses. An asterisk indicates when the response was significantly smaller (P < 0.05) than the response to insulin alone.