The Role Of Human Insulin C-Peptide In The Atherosclerosis Relative Factors In Diabetes Rats Fed With High Lipid Diet

OBJECTIVE: To investigate the correlativity between the C-peptide in different concentration and the relative factors of atherosclerosis in diabetes rats. METHOD: Synthesize the C-peptide cDNA and constructe the express vector pGEX-4T-1 +C-peptide. Induce it by IPTG to acquire C-peptide. type 1 diabetes rats model is established by STZ and divided into 3 groups randomly. type 2 diabetes rats was divided into 4 groups randomly. All the rats were fed with cholesterol and lipid rich diet. 1 Unit 30R insulin per day were subcutaneouly injected to the Rats in group A and 1 Unit 30R insulin plus 3.6ug C-peptide were used to the rats in group B while 1 Unit 30R insulin plus36μg C-peptide were used to those in group C. Only physiological saline was injected in the group D of type 2 diabetes rats. Normal wistar rats were divided into 3 groups randomly and fed with cholesterol and lipid rich diet. 3.6ug C-peptide per day were subcutaneouly injected into the Rats in group A and 36μg C-peptide were injected into the rats in group B while physiological saline was injected in the group C. 12 weeks later we kill the rats and determine the plasma NO level and the activity of NOS synthase of aorta abdominalis and analyse the mRNA level of ICAM-1, VCAM-1, CD40 and D40L .RESULTS: In normal rats and type 1 diabetes rats C-peptide can increase the plasma NO level and artery NOS activity. It can also enhance the expression of VCAM-1, ICAM-1, CD40 and CD40L in type 1 and type 2 diabetes rats and normal rats. CONCLUSION : There is correlativity between C-peptide and atherosclerosis relative factors and perhaps it can effect the artherosclerosis of artery.