Objective To explore the role of parathyroid hormone-related protein(PTHrP) in atheroecelrotic pathological process and protective effects of atorvastatin in a rabbit atherosclerosis model induced by adventitia removal and atherogenic diet.Methods Atherosclerosis was induced in 32 New Zealand male rabbits by left carotid adventitia removal and feeding with atherngenic diet for 4 weeks.Animals were then randomized into 4 groups(n =8) as following:group A receiving PBS(Phosphate buffered saline)(4 ml · kg-1 · d-1) via gavage as control,gronp B receiving atorvastatin (5 mg · kg-1 · d-1) via gavage,group C receiving pluronic F-127 gel around the left carotid artery,and group D receiving PTHrP-(1-34) suspended in such gel around the artery.Four weeks later,the carotid arteries of these animals from each group were removed for morphomelric analysis(HE staining) and PTHrP expression detection(immunohistochemically detected on formalin-fixed,paraffin-embeddod sections).Results Intima thickening and upregulation of PTHrP were observed in left carotid artery in group A,which was significantly aggravated by local PTHrP-(1-34) application and attenuated by atorvastatin treatment.Conclusion Upregulation of PTHrP in the vascular walls might be a novel pathological mechanism of atherosclerosis induced by left carotid adventitia removal and downregulated PTHrP expression might partly be contributed to the beneficial effects of atovastatin on attenuating atherosclerosis in this model.