Hypoxia increased basal [Ca²⁺]_i of PVSMCs <i>in vivo</i> and <i>in vitro</i>.

<p><b>A</b>: Time course effects of hypoxia on basal [Ca²⁺]_i change before and after restoration of extracellular Ca²⁺ to 2.5 mM in distal PVSMCs perfused with Ca²⁺-free Kreb solution containing 10 µM CPA, 1 mM EGTA and 5 µM nifedipine. <b>B</b>: Average peak change in intracellular Ca²⁺ concentration and after restoration of extracellular Ca²⁺ in cells exposed to hypoxia or normoxia control. *P<0.05 versus normoxia control. <b>C</b>: Time course of fura-2 fluorescence at 360 nm normalized to values before and after administration of MnCl₂ (200 µM) to distal PVSMCs perfused with Ca²⁺-free KRB solution containing 10 µM CPA, 1 mM EGTA, and 5 µM nifedipine. <b>D</b>: Average decrease in fura-2 fluorescence at 10 min after administration of MnCl₂ to cells *P<0.05 versus normoxia control.