A free radical scavenger (Tempol) and its effect on intimal hyperplasia of vein grafts in rats.

Abstract

Reversed vein grafting exposes the vessel to a period of ischemia, reperfusion and subsequent reactive oxygen species, which may damage endothelial tissue, smooth muscle cell proliferation and later the development of intimal hyperplasia. Tempol is a free radical scavenger that permeates biological membranes. This study investigates the effects of a free radical scavenger (Tempol) on intimal hyperplasia of femoral vein grafts and the level of reactive oxygen species in rats. Arterial defects created in the femoral artery of rats were repaired with ipsilateral femoral vein grafts. Tempol was administered to group T and saline to group C on a daily basis for a period of 28 days. Blood samples were measured. The veins were stained with H&E and Verhoeff's elastic stains. Binary comparison revealed a statistically significant difference for intimal and medial thicknesses (p<0.01). This study found that a free radical scavenger (Tempol) prevents the early development of intimal hyperplasia, most probably by inhibiting the infiltration of polymorph nuclear monocytes (PNM), with evidence of increased levels of antioxidant products and decreased levels of free oxygen radicals.