Objective To examine the expression and significance of nuclear factor-κB(NF-κB) and matrix metalloproteinases-9(MMP-9) in the carotid artery of type 1 diabetes model INS2AKITA rats.Methods Ten INS2AKITA male rats and ten wild-type C57BL/6 male rats in the same litter were selected as Type 1 Diabetes Model group and contrast group,respectively.The two groups were anesthetized and sacrificed at week 16 after inspection of fasting blood glucose and weighing.Hematoxylin and eosin(HE) staining was performed on carotid artery samples taken from the two groups.Immunohistochemistry was performed to examine NF-κB and MMP-9 protein expressions in endothelial cells of the carotid artery.The NF-κB DNA-binding activity of the carotid artery tissues was inspected by electrophoretic mobility shift assay.MMP-9 mRNA in the carotid artery tissue was measured by real-time polymerase chain reaction.Results Compared with the contrast group,blood glucose rose(P < 0.001) and body weight dropped significantly(P < 0.05) in the type I diabetes model group.The HE staining result shows that the two groups have no apparent intimal hyperplasia.The NF-κB and MMP-9 protein expressions in the endothelial cells of the carotid artery of INS2AKITA rats were higher than those of the contrast group,and NF-κB DNA binding activity increased(P < 0.01).Compared with the contrast group,the expression of MMP-9 mRNA in carotid artery of type 1 diabetes model increased(P < 0.05).Conclusions Intimal hyperplasia was not found in the endothelium of the carotid artery of type 1 diabetic rats at week 16.However,NF-κB and MMP-9 protein expression increased.The NF-κB DNA binding activity and MMP-9 mRNA remarkably increased in the carotid artery,which may be possible early abnormal signs for type 1 diabetic atherosclerosis in the carotid artery.