Abstract: Objective To investigate the effects of extracelluar signal regulated kinase(ERK) pathway on the expression of Smad2/3 protein and mRNA in human umbilical artery smooth muscle cells(hUASMC). Methods hUASMC were primary cultured in vitro,then the hUASMC were divided into four groups:①control group,②PDGF group,③ERK blocking agent group,④PDGF+ ERK blocking agent group.The expression of phosphorylated smad2/3(p-smad2/3) protein in hUSMC were detected by inmunohistochemistry method and the expression of smad2/3 mRNA were detected by RT-PCR technology.Result ①The expression of p-smad2/3 protein in hUSMC of PDGF group was higher than that of control(p<0.01); ②There was no difference on the expression of smad2/3 mRNA in hUSMC between the four groups.Conclusion The ERK pathway could promote the expression of p-smad2/3 protein and have no effection of the expression of smad2/3 mRNA in hUASMC.

Key words: ERK, hUASMC, Smad