Relation Between Urinary Proteinases and Proteinuria in Rats with a Glomerular Disease

Electronegative charges of the glomerular filtration barrier play probably an important role in its impermeability to anionic proteins 1–9. Sialic acid 10 (present in laminin) and glycosaminoglycans 11 seem to be the major molecules responsible for this propriety. Neutral proteinases synthetized either by mesangial cells or by monocytes and neutrophils, infiltrating glomeruli in some pathologic states, are able to degrade GBM glycoproteins in vitro 12–14.