Superoxide dismutase does not improve penetration of endothelium-derived relaxing factor (EDRF) through the vessel wall.

: In superfusion bioassay systems including rabbit aorta donor segment, femoral artery detector rings and porcine circumflex coronary artery donor segment, interventricular coronary artery detector rings, the transwall movement of EDRF was tested. No penetration of the factor through the vessel wall could be detected even after stabilization of EDRF by superoxide dismutase whereas a pronounced relaxation of recipient vessels on intraluminally released EDRF could be seen.