LYSOSOMAL-ENZYMES IN GLOMERULAR CELLS OF THE RAT

  • 1 January 1982
    • journal article
    • research article
    • Vol. 107  (2) , 161-166
Abstract
Whole isolated rat glomeruli (WG) were incubated with bacterial collagenase to separate epithelial cells (EC) from the cores of glomerular tufts (GC), which consisted of mesangial and endothelial cells, as demonstrated by EM. Lysates of WG, EC, and GC and of renal tubules were prepared by hypoosmotic shock and freeze-thawing. Activities of the following acidic lysosomal hydrolases were measured: acid phosphatase, .beta.-glucuronidase, cathepsin-D, nonspecific esterase and aryl sulfatases A and B. The glomerular cell preparations showed activities of all studied enzymes. GC had higher activities than EC, except for nonspecific esterase. Studies of the recovery of acid phosphatase and .beta.-glucuronidase revealed that .apprx. 2/3 of the hydrolase activities present in WG was still measurable after collagenase treatment and that the bulk of this was found in the GC lysates. Apparently, the rat glomerulus and its cell components have considerable biochemical activities of acidic hydrolytic enzymes. These appear to be most prominent in the combined mesangial and endothelial cells of the GC component.