ABSTRACT

Objective To investigate the localization and expression of endothelial nitric oxide synthase (eNOS) within the wall of the human internal mammary arteries (LMA), radial arteries (RA) and the great saphenous veins (SV) using immunohistochemistry method. Methods Specimens were harvested from 20 patients undergoing coronary artery bypass grafting and submitted to light microscope analysis using immunohistochemistry method. Results The expression of eNOS was evident in the intima of LIMA, RA and SV and in the media of muscular LIMA and RA. No eNOS expression was found in the media of great saphenous veins. Semiquantitative and the imaging analysis indicated by gray level values revealed a higher eNOS expression in the wall of internal mammary artery, particularly at the level of the media. Conclusion Different expression of eNOS in the intima and media of LIMA, RA and SV may provide a histological explanation for the better results of the LIMA when used for coronary artery bypass grafting.