Synthesis of the glomerular basement membrane in the rat kidney. Autoradiographic studies with the light and electron microscope.

To study the origin and the formation of the glomerular basement membrane, autoradiographic investigations with 3H-proline and 3H-leucine have been performed in ultrathin with semithin sections of the glomeruli of 42 male rats. The results of this study indicate that, of the three cell types of the glomerulus, the epithelial cells (=podocytes) synthesize the proline-rich scleroproteins of the glomerular basement membrane. Our autoradiographic studies have yielded no evidence for participation of the endothelial or mesangial cells in the formation of the basement membrane. The mesangial cells appear to be responsible for the synthesis of the mesangial matrix only.