Adult human aortic cells in primary culture: heterogeneity in shape

Adult human aortic cells have different shapes in situ. To determine whether populations of cultured aortic cells are also polymorphic, a technique for separation of cells from the intimal and medial layers of the human aorta by enzymatic dispersion of the vascular tissue was employed. It was established that aortic cells are polymorphic in primary culture, at least within the first 7 days after seeding. Four main morphological cell types were identified--elongated, asymmetric, polygonal, and stellate. Polygonal and stellate cells are found only in cultures of grossly normal intima. Elongated and asymmetric cells are present in practically all cultures. The ratio of elongated to asymmetric cells in cultures obtained from healthy aortas and atherosclerotic plaques is more or less the same and is approximately 3:1. In cultures of fatty streaks, the portion of asymmetric cells exceeds 50%. With immunofluorescent staining and ultra-structural analysis, cells of all four types were identified as smooth muscle. Possible reasons for the cells polymorphism in primary culture and the prospects of utilizing this culture method in the investigation of cellular aspects of atherogenesis are discussed.