Quantitative analysis of tissue organization of the rat aorta endothelium during regeneration

Cold injury to the abdominal aorta was performed in experiments conducted in 25 albino rats. Perfusion fixation of vessels with impregnation of intercellular contacts of the endothelium was performed at 1, 3, 14 days, 3 and 6 months after surgery. The preparations were examined by scanning electron microscopy. Changes in the area of endothelial cells (EC) during regeneration (within the first 14 days) correlated with concomitant processes; while EC proliferation and migration were associated with an increase in EC area, the area diminished during EC division. Still, even with suppressed EC proliferation, endothelial layer re-arrangement by means of desquamation of individual argyrophil cells and compensating spreading of adjoining endotheliocytes could be seen. Results of an analysis of the tissue mosaic of newly formed endothelium indicate a gradual decrease in its organization during regeneration and after it.