Korean J Thorac Cardiovasc Surg.  2001 Jul;34(7):515-523.

The Protective Effects of Ascorbic Acid on the Vascular Motilities in Streptozotocin-induced Diabetic Rat

• Kim YJ
• Yang KM
• Cho DY
• Sohn DS
• Lee MY

Abstract

BACKGROUND: More than 70% of morbidity and mortality of diabetes mellitus is due to macrovascular complications. These complications may be associated with defect of endothelium-dependent vascular relaxation. There have been suggestions that this defect might be due to direct toxicities of oxygen-free radical. So in this study ascorbic acid was used as a dietary supplement in streptozotocin induced diabetic rats to correct this defect. MATERIAL AND METHOD: Sixty male Sprague-Dawley rats were used in this study. They were divided into control and experimental groups. Streptozotocin was injected to the 33 rats of experimental group and then divided into two the other receiving subgroups; one receiving ascorbic acid supplement(1 g/l in drinking water); and nosupplements. At 6, 9 and 12 weeks, abdominal aortic rings were obtained to make tissue preparations for evaluation of vascular smooth muscle contractility. RESULT: While control group showed good response to acetylcholine induced relaxation, diabetic group showed decreased relaxation regardless of ascorbic acid supplement at the experiments 6 weeks after streptozotocin treatment. This abnormal endothelium-dependent vascular relaxation was markedly reversed at 9 and 12 weeks into the diabetic group with ascorbic acid supplement. There were no differences in sodium nitroprusside induced relaxation responses between control and experimental groups; also, norepinephrine induced contractile responses did not show any remarkable effects.
CONCLUSION
These results strongly suggest that the endothelial cells have defects in diabetic rats. Dietary supplement of ascorbic acid can reverse the defects of diabetic endothelial cells through its antioxidant effects and it may further protect against vascular disease in diabetic patients.

Keyword

Diabetes mellitus; Vit C; Vascular motilities

MeSH Terms

Acetylcholine
Animals
Antioxidants
Ascorbic Acid*
Diabetes Mellitus
Dietary Supplements
Drinking
Endothelial Cells
Humans
Male
Mortality
Muscle, Smooth, Vascular
Nitroprusside
Norepinephrine
Rats*
Rats, Sprague-Dawley
Relaxation
Streptozocin
Vascular Diseases
Acetylcholine
Antioxidants
Ascorbic Acid
Nitroprusside
Norepinephrine
Streptozocin