Abstract: Objective To study whether Heme Oxygenase-1（HO-1） can alleviate the oxidative damage caused by serum of smoking rats on human umbilical vein endothelial cell(HUVEC). Methods Fifteen male Sprague-Dawley rats were randomized into control group,smoking group,and smoking with Zincprotoporphyrin(ZnPP) group.Western blot was used to detect the expression of HO-1 in carotid arteries of the rats.Also the expression of HO-1was detected in HUVEC cultured in the serum of normal rats,smoking rats and smoking with ZnPP rats.The reactive oxygen species were detected in HO-1-overexpressing and HO-1-lowexpressing HUVEC ,cultured in the serum of smoking rats.Results The expression of HO-1 in carotid arteries of smoking rats was significantly higher than that of normal rats(P ＜0.01).Both the serum of smoking rats and HO-1depressed smoking rats could induced the expression of HO-1 in HUVEC,and the role of the latter was more obvious(P ＜0.01).The reactive oxygen species of HUVEC cultured in the serum of smoking rats were more than that cultured in the serum of nornal rats(P＜0.01),also the HO-1 could release the oxidative damage(P＜0.01).Conclusion Smoking can cause the oxidative damage to HUVEC ,and HO-1 can alleviate the damage.

Key words: smoking, heme oxygenase-1, vascular, endothelial cell, oxidative damage