ABSTRACT
Aim To investigate the effects of iptakalim(IPT),a novel K_(ATP) opener,on the functions of endothelin system in human pulmonary artery endothelial cells.Methods Primary cultured human pulmonary artery endothelial cells were incubated with different concentrations iptakalim for 24 h.The levels of ET-1 in medium were observed by radioimmunoassay.Reverse transcription polymerase chain reaction(RT-PCR)was performed to analyze the expression of ET-1 and ECE.Results When endothelial cells were incubated with IPT at concentrations above 10 μmol·L~(-1),the levels of ET-1 release in medium and the levels of ET-1 mRNA were significantly inhibited.When endothelial cells were incubated with IPT at concentrations above 1 μmol·L~(-1),the levels of ECE mRNA were significantly inhibited.Conclusions IPT can inhibit the expression of ET-1 and ECE mRNA from human pulmonary artery endothelial cells, thus it inhibits the secretion of ET-1 from endothelial cells. Iptakalim may serve as a promising candidate drug to treat pulmonary hypertension.