[Ultrastructure of the inner surface of the aorta of mature and old animals].

In the experiments, performed on 12 white rats and 8 rabbits, by means of scanning electron microscopy of the native preparations and in a number of cases with use of silver nitrate impregnation, the internal surface structure has been studied in the aortal membrane of mature and old animals. At ageing the integrity and continuity of the endothelial monolayer is preserved, on the surface local intimal pits, craters and microdefects appear, adhesiveness of endothelium to leucocytes increases. Orientation of the intimal folds is disturbed. The type of the senescent remodeling in the endothelial layer revealed predisposes to development of atherosclerosis.