Growth and maintenance of glomerular cells under defined conditions.

Glomeruli grown in the absence of fetal calf serum (FCS) but in the presence of several hormones did not have the prominent perinuclear granules seen in cells grown in serum. Cells grown in chick embryo extract ultrafiltrate (CEE-U) plus fibroblast growth factor (FGF) showed both well-differentiated and poorly differentiated epithelial cells, neither of which had perinuclear granules. It was possible to maintain glomeruli for several weeks in media containing CEE-U plus FGF plus low concentrations of FCS without attachment of glomeruli or subsequent cell proliferation. When these cells were transferred to 30% FCS, they showed morphologic properties intermediate between those of well-differentiated and poorly differentiated epithelial cells.