CULTURE OF ENDOTHELIAL-CELLS FROM HUMAN PLACENTAL MICROVESSELS

Endothelial cells are known to participate in angiogenesis, adaptation of vascular tonus and maintenance of blood fluidity in the microcircu lation. To investigate these functions in the placenta, we devised a m ethod of isolation and culture of endothelial cells from villous micro vessels. In primary culture, these intraplacental endothelial cells ex hibited many features observed in microvascular endothelium from other organs: spindle-shape, rosette associations, circular arrangements an d confluence. In contrast to the confluent endothelial cells derived f rom the umbilical vein, cells from microvessels did not form a cobbles tone network. After trypsin digestion of microvessels, magnetic microb eads coated with S-Endol immunoglobulin, antithrombomodulin and Ulex e uropaeus-I lectins were tested for sorting endothelial cells. Only the microbeads coated with antithrombomodulin allowed a suitable magnetic cell separation after trypsinization. By contrast, the microbeads coa ted with each of these antibodies or with lectins attached to confluen t cells from the second passage. The microbeads detached from the cell s at different rates. Their examination by scanning microscopy indicat es that a portion of these microbeads was phagocytosed. Microvascular endothelial cells from the second passage were intensively stained by the anti-von Willebrand reaction and only weakly by the anti-smooth mu scle alpha-actin reaction. They incorporated acetylated-low density li poproteins coupled to a fluorescent probe. The positive reactions agai nst the anti-von Willebrand factor and the uptake of the fluorescent a cetylated-low density lipoproteins were modified after eight passages.