Three-dimensional changes of the cytoskeleton of vascular endothelial cells exposed to sustained hydrostatic pressure

The three-dimensional changes in the cytoskeleton and in cell proliferation of bovine pulmonary artery endothelial cells when exposed to sustained hydrostatic pressure were investigated in vitro using laser scanning confocal microscopy. Subconfluent endothelial cells on rigid substrates were exposed to 1.5, 5 and 10 cm H₂O pressure under hydrostatic heads of culture medium for up to seven days. Confocal microscopic images were taken at distances of 0.4 μm through the thickness of the sample and visualised in multiplanar, stereopair and 90^o rotation formats. The results of the study provide evidence of: increased proliferation after exposure to 10 cm H₂O pressure for five and seven days; cell bilayering after exposure to 1.5 and 5 cm H₂O pressure and trilayering after exposure to 10 cm H₂O pressure for seven days; and F-actin filament reorganisation into centrally located, parallel, stress fibres in confluent cells, into peripheral bands in subconfluent, multilayered cells, and into multilayers in the plane perpendicular to the applied force.