Aim To investigate the effect of diabetes on rat vascular calcification,and the expression of Msx2 and Wnt3a mRNA in calcified artery of diabetic rat.Methods 48 male Wistar rats were randomly divided into 4 groups:vitamin D3 and nicotine(VDN)group(n=12)undergoing vitamin D3 and nicotine treatment,and diabetes mellitus(DM)group(n=12)undergoing injection of streptozotocin(STZ)to induce diabetes,and diabetes mellitus & vitamin D3 and nicotine(DM+VDN)group(n=12)undergoing injection of STZ and vitamin D3 and nicotine treatment.Another 12 rats were used as normal controls(CON group,n=12).Measurements of metabolic parameters(glucose,insulin,total cholesterol and triglyceride)were performed.von Kossa calcium stain,aortic calcium content and alkaline phosphatase(ALP)activity were used as indicators to determine the extent of vascular calcification.Real-time PCR was performed to detect the expression of Msx2 and Wnt3a mRNA.Results Compared with CON group,four weeks of vitamin D3 and nicotine treatment alone increased the expression of Msx2 and Wnt3a mRNA in aorta slightly(P<0.05),but there were no significant differences in aortic calcium content or ALP activity.In the DM+VDN group,calcium deposition in aorta,aortic calcium content,ALP activity and expression of Msx2 and Wnt3a mRNA in artery increased significantly compared with CON group and VDN group(P<0.05).Conclusion Diabetes may accelerate vascular calcification.Bone-associated transcript factors,Msx2 and Wnt3a are up-regulated in calcified artery of diabetic rat.It suggests that vascular calcification is a process similar to bone formation,and Msx2 and Wnt3a may involve in the occurrence of vascular calcification.