Korean J Pathol.
2000 Jan;34(1):56-67.
Ultrastructural Changes in Glomerular Anionic Sites in Puromycin Aminonucleoside Nephropathy
- Affiliations
-
- 1Departments of Internal Medicine, Keimyung University School of Medicine, Taegu 700-712, Korea.
- 2Departments of Pathology, Keimyung University School of Medicine, Taegu 700-712, Korea.
Abstract
- An ultrastructural study was done on puromycin aminonucleoside (PAN) nephropathy
which was induced in a group of Sprague-Dawley rats by a single intraperitoneally injected
dose. To study the ultrastructural alteration of glomerular anionic sites renal tissue was
stained with polyethyleneimine (PEI) as a cationic probe. The PEI method seemed to
selectively stain heparan sulfate proteoglycan in the basement membrane and has been
widely used to evaluate the changes of the basement membrane in human diseases as well
as in experimental work. The experimental rats developed proteinuria three days after the
PAN injection. Electron microscopic studies of glomeruli showed the loss of epithelial foot
processes, formation of cytoplasmic vacuoles, microvillous formation, and increased numbers
of lysosomes in the cytoplasm of podocytes. The anionic sites on the basement membrane
with foot process fusion were mostly indistinguishable from those seen in control rats, but
focal areas of loss or disarray of anionic sites were noted. The anionic sites were not seen
on the basement membrane where the overlying epithelium was detached. The results
suggest that proteinuria in PAN nephrosis may be primarily due to a glomerular epithelial
lesion, leading to focal disarray of anionic sites or focal defects in the epithelial covering of
the basement membrane. The loss of anionic sites in the basement membrane may result
partially from the foot process fusion, but mostly from the epithelial detachment.