Production and polarized secretion of basement membrane components by glomerular epithelial cells

To study the formation of basement membrane by glomerular epithelial cells (GECs), production and secretion of type IV collagen and laminin by rat GECs in culture were evaluated. GECs produced two chains of type IV collagen in the ratio of approximately 2 to 1, when immunoprecipitated with antibody to type IV collagen of mouse Engelbreth-Holm-Swarm sarcoma. The results indicate that cultured GECs are polarized and that they produce and secrete basement membrane components via the basolateral side.