ABSTRACT
Background The ubiquitin-proteasome pathway(UPP)involves 80%-90% degradation of all in- tracellular proteins.Both ubiquitin and rat component 3 of proteasome(RC3)are hence considered to be central me- diators for cell biology.Objective To evaluate the effect of simvastatin on neointimal hyperplasia and the expres- sion of ubiquitin and rat component 3 of proteasome(RC3)after balloon injury in carotid artery.Methods Thirty- two male SD rats were randomly to receive,low dose(0.4 mg/ng,n=8),or moderate(4 mg/ng,n=8),or high- dose(40 mg/ng,n=8)of simvastatin treatment for 28 days.Common carotid aortic artery was injuried rat ballon. The ratio of intima-media(I/M)thickness was determined.The expression level of ubiquitin and RC3 mRNA were assessed by RT-PCR.The expression level of ubiquitin protein was examined with immunohistochemistry. Results Simvastatin inhibited the expression of ubiquitin and RC3 mRNA and ubiquitin protein in dose dependent manner.The intima-media ratio(-50.2 %)and the expression of ubiquitin(-60.3 %)and RC3 mRNA and ubiq- uitin protein(-60.5 %)was reduced by the high dose simvastatin [40 mg/(kg?d)](P