Effect of levcromakalim on ET-1 induced proliferation and expression of protein kinase C in vascular smooth muscle cells

AIM:To observe the effect of levcromakalim(Lev) on endthelin-1(ET-1) induced proliferation and the expression of protein kinase C(PKC) in cultured rat vascular smooth muscle cells(VSMCs).METHODS: VSMCs were isolated from rat aorta and were cultured with different concentrations of Lev in vitro after stimulated to proliferation by ET-1(10~(-8)(mol·L~(-1))).Vitality of VSMCs was detected by MTT;DNA replication was evaluated by 3H-TdR method.Flow cytometry was used to analyze cell cycle and apoptosis.The expression of PKCα protein and mRNA were determined by Western blot and reverse transcription-polymerase chain reaction(RT-PCR).RESULTS:Vitality of VSMCs and 3H-TdR intermingle rate were decreased(P(0.05)) in a dose dependent manner which indicated Lev inhibited VSMCs proliferation by inducing ET-1.Levcromakalin increased the ratio of VSMCs apoptosis(P(0.01)).The cell cycle was blocked at G_0/G_1 phase by Lev in a dose dependent manner(P(0.05)).Levcromakalim decreased the expression of PKCα protein and mRNA in VSMCs(P(0.05)).CONCLUSION: Levcromakalim inhibits VSMCs proliferation by inducing ET-1 through reducing the expression PKCα.