Collagen synthesis by human glomerular cells in culture.

Collagen synthesis was studied in three subcultured human glomerular cell types, by radiolabeled incorporation of [14C]proline and [3H]lysine. The epithelioid circular glomerular cells secrete a collagen with a single size of chain (possibly type IV) with a high ratio of hydroxyproline to proline, hydroxylysine to lysine, and 11--17% of hydroxyproline as the 3-isomer. The smooth muscle-like rhomboid glomerular cells secrete collagen with a chain pattern suggesting types III and I collagen, distinct from that found in the media of fibroblasts. Small ovoid glomerular cells are morphologically and biochemically intermediate between circular glomerular cells and rhomboid glomerular cells, and may represent an in vitro modification of either circular glomerular cells or rhomboid glomerular cells.