Abstract
Aims/hypothesis. The impact of early vitamin E supplementation on vascular function in diabetes remains unresolved. Therefore, we examined the effects of vitamin E on functional and structural parameters and on chemical markers that are disturbed in diabetes in mesenteric and femoral arteries. Methods. Segments of both arteries, taken from control and 8-week-old streptozotocin diabetic Wistar rats that were treated or not with vitamin E, were mounted on wire and pressure myographs, after which endothelium-dependent and -independent vasodilation was assessed. Passive mechanical wall properties and the localisation and levels of protein kinase C (PKC)-β2 and AGE were evaluated in these vessels. Results. Vitamin E supplementation was associated with improved endothelium-dependent and -independent vasodilatation in mesenteric arteries from diabetic rats. Impaired endothelium-dependent vasodilatation in diabetic mesenteric vessels was associated with PKC-β2 up-regulation and this was prevented by vitamin E supplementation. Increased AGE accumulation and plasma isoprostane levels in diabetic rats were not changed by vitamin E. In the femoral artery, vitamin E supplementation had no effect on endothelium-dependent or -independent vasodilatation, but did prevent the wall stiffening associated with diabetes. Conclusions/interpretation. Early vitamin E supplementation has a beneficial effect on diabetes-induced endothelial dysfunction in resistance arteries. This benefit may arise from a direct effect on smooth muscle function, as a result of inhibition of the PKC-β2 isoform by vitamin E.
Original language | English |
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Pages (from-to) | 1038-1046 |
Number of pages | 9 |
Journal | Diabetologia |
Volume | 47 |
Issue number | 6 |
DOIs | |
Publication status | Published - 1 Jan 2004 |
Keywords
- Advanced glycation end-products
- Diabetes
- Endothelial function
- Endothelium-derived hyperpolarising factor
- Femoral artery
- Mesenteric artery
- Protein kinase C
- Sodium nitroprusside
- Stress-strain relationship
- Vitamin E