Aortic endothelial cells injury induced by oxidative stress in type 2 diabetes rats and the protective effect of valsartan / 中国药理学通报

ABSTRACT

Aim To investigate the relationship between oxidative stress and the aortic endothelial cells injury in type 2 diabetes rats,as well as the effect of valsartan. Methods The type 2 diabetic models were induced by low dose of streptozotocin (STZ) with high-energy diet.12 weeks after injecting STZ, rats were randomly divided into three groups normal control, diabetes control and valsartan (24 mg?kg-1?d-1, 8 weeks, ig.) treated diabetes. At the 12th and 20thweek end, such indices as the endothelium-dependent vasodilation and the shape of aorta endothelium, the serum contents of SOD, GSH-Px , MDA and NO, and the level of NOS gene expression in aorta were measured. Results ① At the 12th weekend,in the diabetes group, the relaxation of aortic rings to low concentration of Ach declined, the aortic endothelial cells intumesced, contents of serum SOD, GSH-Px, MDA and NO significantly increased, the expression of iNOS mRNA in aorta obviously up-regulated while the expression of eNOS mRNA showed no change. ② At the 20th weekend,in the diabetes control group, the dilatory reactivity of aortic rings decreased to each concentration of Ach, the aortic endothelium appeared degenerative and necrotic, activities of SOD and GSH-Px decreased as well as the content of NO, the content of MDA increased continuously, and the iNOS mRNA expression up-regulated while eNOSmRNA expression down-regulated. Valsartan could regress the aggravation and improve contents of serum SOD, GSH-Px, MDA, NO and NOS mRNA of the aorta. Conclusion The oxidative stress and abnormality of NO participate the process of aortic endothelial cell injury. Valsartan plays a protective role partially through enhancing antioxidation effect and adjusting NO production.