[The beneficial effect of natural antioxidants on the endothelial function of regenerated endothelium].

HYPOTHESIS

Lipid peroxidation and LDL oxidation have been implicated in intimal hyperplasia and endothelial dysfunction following direct arterial trauma.

OBJECTIVES

The aim of this study was to evaluate the effects of megadose of natural antioxidant vitamin E (VE) combined to vitamin C (VC) on the regenerated endothelial dysfunction.

METHOD

A first group of rats (VE and C) (n = 10) was pretreated with VE (500 IU/kg/day) and VC (1200 mg/kg/day) for 4 weeks before aortic (thoracic) endothelial denudation with a Fogarty catheter. Rats were then fed with the same vitamin supplemented diet for 2 months. A second group (n = 10) was similarly denuded and treated with soya oil (SO), VE vehicle, for the same period; a third group (n = 10) was denuded only (DN); and a fourth group was maintained on a regular diet (CL) without denudation. Endothelial-dependent and independent relaxation was assessed in organ chambers.

RESULTS

Vascular relaxation to nitric oxide analogue sodium nitroprusside was not affected either by the regenerative process or the vitamin supplementation. However, endothelial-dependent relaxation to acetylcholine, was significantly preserved in VE and C (p < 0.01) treated animals compared to DN group.

CONCLUSION

These results suggest that, in this model, dietary megadose of antioxidants vitamin initiated 4 weeks before denudation can improve the post-regenerative endothelial dysfunction and could contribute to the prevention of the atherosclerotic process.