Objective:To study the effect of sesamin on aortic function in metabolic syndrome rats

and to explore its possible mechanism.Methods:A high-fat and refined-carbohydrate diet induced metabolic syndrome.Sesamin(120

60

30 mg·kg-1·d-1) was given by intragastric administration to metabolic syndrome rats at the 9th week

then lasted for 16 weeks.After 24 weeks

blood pressure

blood fat

blood glucose

hydrogen peroxide and nitrate/ nitrite in serum were determined.In addition

the vascular function test was performed.The thoracic aortic ring of rats was mounted on a bath system.The effect of sesamin on the contraction elicited by phenylephrine and the relaxation induced by acetylcholine and sodium nitroprusside were measured.To explore the mechamism

expression of endothelium nitric oxide synthase(eNOS) and nitrotyrosine in aorta were observed by immunohistochemical method.Results: Sesamin obviously decreased the level of blood pressure

blood fat

blood glucose

serum hydrogen peroxide and increased concentration of nitrate/nitrite in rats;it also enhance the relaxation induced by acetylcholine and raised expression of eNOS and depressed expression of nitrotyrosine in aorta.Conclusion: Sesamin may improve the endothelium-dependent relaxation dysfunction

possibly though decreasing the level of oxyradicals

increasing expression of eNOS in aorta

and raising concentration of NO or recovering its bioactivity.