[Structural peculiarities of the wall of the vessels of the cerebral arterial circle in the area of bifurcations in people of different age].

The present study was conducted to determine the morphological and morphometric features of the arterial wall structure at the bifurcation of blood vessels of the cerebral arterial circle (CAC) of Willis in people of different age (from birth till 65 years). Material obtained from 80 people was stained with hematoxylin-eosin, Van Gieson stain, with orcein by Unna-Taenzer's method and with sudan. The proliferative activity of the cells in tunica intima and tunica media at the site of bifurcation of the internal carotid and basilar arteries was studied immunohistochemically using monoclonal antibodies against Ki-67. It was found that intimal thickenings (cushions) appeared immediately after birth, initially only in a few places of CAC vessel branching; by 8-10 years they were detected in all the bifurcations of the circle. With aging, the thickening of intimal cushions with a thinning of the underlying tunica media was found. Ki-67 protein expression was noted in both the intimal cushions and underlying tunica media, indicating the activity of atherosclerosis process.