Primary cultures of endothelial cells of the rat liver: a model for ultrastructural and functional studies.

A new isolation and purification procedure for endothelial cells of the rat liver and the conditions for large scale survival of these cells in maintenance culture are reported. Cells isolated by this new method and cultured with homologous rat serum on a collagen matrix show the restoration of several ultrastructural characteristics typical of rat liver endothelial cells in situ, including the broad cytoplasmic extensions that contain the sieve plates. These fenestrated cytoplasmic projections, which cover the liver sinusoids in vivo, are well preserved and are reformed in a manner reminiscent of the situation in situ. Reformation of specific membrane receptors is indicated by the reappearance of the capacity to take up horseradish peroxidase by adsorptive endocytosis, a characteristic that is lost during the cell isolation procedure. From the results obtained in this study, maintenance culture of rat liver endothelial cells seems to be a promising system for studying the regulation of pore size of the fenestrated sieve plates by alcohol and certain hormones, for studying the interaction of endothelial cells with other liver cells and tumor cells, and for studying the mechanisms of adsorptive endocytosis.