Morphogenesis of intimal thickening in nonspecific aortoarteritis.

Hyperplastic intima in nonspecific aortoarteritis was investigated immunomorphologically and by means of electronmicroscopic autoradiography. The cellular composition of the involved vascular wall was studied by the method of alcohol-alkaline dissociation. The prevalence of elongated cells with side processes and stellate cells in thickened intima was shown. These cells are characterized by essentially intensive RNA synthesis and, according to the electron microscopic data, can be regarded as pericytes. A significant amount of capillaries and precapillaries in thickened intima was visualized. Distribution of laminin and type IV collagen coincided with localization of the basal membrane of the vasa vasorum and with that of microvessels growing in the intima. Considered together, these data suggest that pericytes that surround a capillary/precapillary network may play a significant role in the morphogenesis of vascular transformation in nonspecific aortoarteritis intimal thickening.