Effects of Iptakalim on intracellular free calcium concentration of cultured rabbit pulmonary arterial smooth muscle cells

摘要

Objective:To explore the effects of Iptakalim on intracellular free calcium concentration and on the proliferation of cultured rabbit pulmonary arterial smooth muscle cells induced by endothelin-1(ET-1) in vitro.Methods:A cell culture model,[~3H]-thymidine([3~H]-TdR) incorporation test and confocal microscope were used to observe proliferation and intracellular free calcium concentration([Ca^(2+)]_i) of rabbit PASMC induced by ET-1 in vitro.Results:The value of [3~H]-TdR incorporation in ET-1 group was increased 1.468 times higher than that in control group.Iptakalim at the concentration of 10^(-7)mol/L,10^(-6) mol/L,10^(-5) mol/L lowered [~3H]-TdR incorporation by (19.8±4.6)%,(41.2±9.5)%,(54.7±10.1)%,respectively,compared with the value of the cells treated with ET-1(P<0.01); The intracellular fluorescence intensity of PASMC in ET-1 group was increased from 73.70±10.12 to 143.84±28.23,significantly higher than that in control group(P<0.01);whereas with Iptakalim,the fluorescence intensity(FI) was only increased from 74.30±10.20 to 86.03±9.82,significantly lower than that in ET-1 group(P<0.01).Conclusion:Iptakalim inhibited proliferation of PASMC and decreased intracellular free calcium concentration of cultured rabbit PASMC induced by ET-1.