Regulation of bovine glomerular endothelial cell growth in vitro.

To enable the study of glomerular endothelial cell functions and interactions with other glomerular cells, bovine glomerular capillary endothelial cells were established in culture. Selective media were used to facilitate endothelial cell proliferation and to suppress glomerular mesangial cell growth. Glomerular endothelial cells were separated from other cell types by fluorescence-activated cell sorting or, alternatively, by cloning. Glomerular endothelial cells expressed angiotensin I-converting enzyme and factor VIII activity and acetylated LDL uptake, properties generally held to be specific for endothelial cells. Proliferation of subconfluent glomerular endothelial cells was stimulated by basic fibroblast growth factor and, in the presence of heparin sodium, by acidic fibroblast growth factor. Platelet-derived growth factor was without effect on glomerular endothelial cell proliferation. Coculture with mesangial cells markedly inhibited proliferation of subconfluent glomerular endothelial cells. By contrast, medium conditioned by confluent glomerular endothelial cells markedly enhanced proliferation of subconfluent glomerular endothelial cells. These findings suggest that glomerular endothelial cell growth is under autocrine and paracrine control.