Effects of endothelial denudation in flow-induced arterial dilatation.

The effects of endothelial denudation of the flow-induced arterial dilatation in the rabbit common carotid artery (carotid) were studied. After endothelial denudation with a 3-French balloon catheter, the left carotid was made arterio-venous (A-V) fistula to the left external jugular vein in four adult male rabbits (3-4 kg). Five rabbits which were given A-V fistula without denudation were used as controls. Blood flow rates, luminal dimensions, hemodynamic parameters and morphology were studied after 1 week. In spite of a significant increase of blood flow, the lumen diameter of the left carotid with denudation was significantly smaller than that without denudation. The assumed wall shear stress in the left carotid with denudation was significantly higher than in that without denudation. In the denuded segment, the internal elastic lamina and media were preserved with no or slight intimal thickening, composed of mononuclear cell proliferation; however, there were frequent disruptions of the internal elastic lamina in the non-denuded left carotid. We consider that flow-induced arterial dilatation occurs when the endothelial lining is preserved.