Glomerular Lysosomal Enzymes in Aminonucleoside Nephrosis

Abstract

Lysosomal hydrolases produce degradation of glomerular basement membrane and may play a key role in catabolism of glycoproteins of extracellular matrix in glomeruli. Therefore we investigated activities of some lysosomal enzymes and stability of lysosomes in glomeruli of normal and nephrotic rats. Nephrosis was induced in rats by single injections of puromycin aminonucleoside. In glomeruli from nephrotic rats we found lower activities of β-fucosidase and arylsulfatase, but activity of acid phosphatase was higher compared with control rats. Osmotic stability of lysosomes measured by release of β-glucuronidase was decreased in nephrotic rats. Abnormal activity of lysosomal enzymes and altered physiology of lysosomes in glomeruli may be a pathogenic factor in the altered glycoprotein metabolism in nephrotic syndrome and perhaps also in other glomerular diseases.

Expression of Cathepsin L and Its Intrinsic Inhibitors in Glomeruli of Rats With Puromycin Aminonucleoside Nephrosis

“…36,37 The stability of lysosomal membrane decreases in PAN nephrosis. 38 Accordingly, lysosomal enzymes with acidic fluid in the podocytes of PAN nephrosis may easily leak into the cytoplasm when lysosomal membrane is expanded by a large amount of endocytosis proteins as observed in our study. In vitro, PAN-treated podocytes showed a strong cathepsin L staining throughout the cytoplasm.…”