Figure 3.

In a number of unpaired experiments, arterioles were subjected to depolarization with varying extracellular [K⁺]. The concentration−peak response curve indicates activation of Ca²⁺ entry between 15 and 25 mM extracellular K⁺ and the response is maximal at approximately 75 mM K⁺. The number of arterioles used is shown within parenthesis.