Tissue culture of normal rat glomeruli: characterization of collagenous and non-collagenous basement membrane antigens on the epithelial and mesangial cells.

Immunofluorescent studies were performed on epithelial and mesangial cells derived from normal rat glomeruli, using specific antisera directed against insoluble glomerular basement membranes (GMB), or directed against either type IV procollagen or non-collagenous antigens purified from basement membrane polypeptides synthesized by a murine tumour. In marked contrast to the mesangial cells, the epithelial cells contained large amounts of GBM antigens, of type IV procollagen, and of non-collagenous glycoproteins in the first two days after subculture plating. At the same time, the mesangial cells did not exhibit any basement membrane antigens. Five to 10 days later, however, all the antisera tested stained the surface membrane and/or the extracellular material of both epithelial and mesangial cells. The data suggest that both cell lines synthesize and secrete cross-reacting type IV procollagen and non-collagenous basement membrane antigenic material into the culture medium.