Factors controlling the in vitro growth pattern of human microvascular endothelial cells.

Monolayer cultures of endothelial cells of human dermal microvascular origin were exposed to a variety of culture conditions and in vitro differentiation of the cells assessed by light and electron microscopic examination. Restoration of a cytologic and fine structural appearance which resembled most closely that present in vivo was possible by raising the intracellular cAMP level. These cells formed junctional complexes seen in uncontracted microvessels and specialized attachment sites at their basal cell membrane, contained a complex network of bundled micro- and intermediate filaments and numerous Weibel-Palade bodies and accumulated electron-opaque deposits between the cells and the culture dish surface.