[Effect of transient hypoxia on the permeability of rat aorta. Electron microscopic study]

Infrarenal part of the abdominal aorta in rats was closed out from the circulation by the aid of a doubled ligature. Changes of the permeability at different intervals after recirculation were investigated using colloidal iron as a labelling substance. The latter in an hour after recirculation could already be detected in the interendothelial junction and in the subendothelial space. The lesion of the permeability was most striking on the second day, and on the tenth day no more lesion could be observed. Increase of the permeability of the endothelium was paralelly followed by an inhibition of the media, which leads to significant ultrastructural changes.