Effects of rat hepatocytes on macromolecular permeability of bovine aortic endothelial cell monolayer.

The aim of this study was to examine whether the hyperpermeable structure of the liver endothelium in vivo is related to the interactions of hepatocytes in a culture system. The permeation of macromolecular FITC-labeled dextran (molecular weight 70,000) through a monolayer of bovine aortic endothelial cells (BAEC), cocultured with rat parenchymal hepatocytes (P-hep), was increased. When the BAEC were cocultured with nonparenchymal hepatocytes (N-hep), the permeability of the BAEC monolayer was not increased. However, when the BAEC were cocultured with a mixture of P-hep and N-hep (PN-hep), the BAEC monolayer was more permeable than when BAEC were cocultured with P-hep alone. The conditioned medium of P-hep did not alter the BAEC monolayer permeability, nor did the extracellular matrix of P-hep alter BAEC permeability. When the BAEC were cocultured with PN-hep, the F-actin content was not altered. These findings suggest that the interaction between hepatocytes and endothelial cells exerts an important effect on the hyperpermeable structure of the liver vessels in vivo.