Effects of pinacidil on intracellular free calcium concentration of primary cultured human pulmonary artery smooth muscle cells

Objective To study the effects of pinacidil on the proliferation and intracellular free calcium concentration of primary cultured human pulmonary artery smooth muscle cells (PASMCs) induced by endothelin-1 (ET-1). Methods The experimental models of proliferation of primary cultured human PASMCs induced by ET-1 in vitro were established.The influence of pinacidil on vitality of PASMCs was detected by MTT,and intracellular free calcium concentration (\[Ca2+\]i) was observed by the fluorescence Ca2+ indicator Fluo-3/AM. Results Pinacidil inhibited the proliferation of human PASMCs in a concentration-dependent manner.Glibenclimide,a selective ATP-sensitive K+ (KATP) channel blocker,abolished the effect of pinacidil on the cell proliferation in a concentration-dependent manner. The treatment with ET-1 resulted in a transient raise of \[Ca2+\]i in human PASMCs,which could be blocked by pinacidil 10 μmol/L.Conclusion Pinacidil inhibits the proliferation of human PASMCs and decreases intracellular free calcium concentration of cultured human PASMCs induced by ET-1.