Variant endothelial cells from human carotid artery in culture.

Endothelial cells were cultured from the carotid artery with thickened intima comprised of two to five layers of smooth muscle cells, isolated from a 19-yr-old female, who died from an accident. The cells were grown and subcultured in Medium 199 supplemented with 20% heat inactivated fetal bovine serum. The cells are still viable at present, the 22nd passage. The cultured cells were found to have the following characteristics: existence of Factor VIII-related surface antigen and prostacyclin synthesis slightly less than that for typical endothelial cells. The most outstanding feature was the formation by an individual cell of a single ring, and a composite ring formed by two to five cells. Neither the synthesis of an angiotensin converting enzyme nor that of a Weibel-Palade body could be detected by electron microscopy. The cultured cells possessed only a few characteristics specific for typical endothelial cells and were designated as variant endothelial cells.