J Vet Sci.  2013 Jun;14(2):223-226. 10.4142/jvs.2013.14.2.223.

Analysis of ultrastructural glomerular basement membrane lesions and podocytes associated with proteinuria and sclerosis in Osborne-Mendel rats with progressive glomerulonephropathy

• Yasuno K
• Kamiie J
• Shirota K

• KMID: 1705525
• DOI: http://doi.org/10.4142/jvs.2013.14.2.223

Abstract

The renal glomeruli of 12 male Osborne-Mendel (OM) rats 3 to 24 weeks old were examined by electron microscopy. Effacement of podocyte foot processes (FPs) developed at 3 weeks of age and became progressively worse over time. Loss or dislocation of the slit membrane was also found. Vacuoles and osmiophilic lysosomes appeared in the podocytes starting at 6 weeks of age. Podocyte detachment from the glomerular basement membrane (GBM) was apparent at 18 weeks of age. Laminated GBM was occasionally observed in all animals. These features might lead to the development of spontaneous proteinuria and glomerulosclerosis in OM rats.

Keyword

glomerular basement membrane; kidney glomerulus; podocyte; proteinuria; rat

MeSH Terms

Animals
Animals, Outbred Strains
Glomerular Basement Membrane/*pathology/ultrastructure
Kidney Diseases/complications/etiology/*pathology
Male
Microscopy, Electron, Transmission
Nephrosclerosis/etiology/pathology
Nephrosis/complications/pathology
Podocytes/*pathology/ultrastructure
Proteinuria/etiology/pathology
Rats

Figure

• 

  Fig. 1 Representative features of renal glomeruli in male Osborne-Mendel (OM) rats observed with light microscopy. (A) Non-sclerotic glomerulus of a 6-week old male OM rat showing a few hyaline droplets (arrow) in the podocyte. Periodic acid-Schiff (PAS) staining. (B) Non-sclerotic glomerulus of a 6-week old male OM rat with no significant changes. Semi-thin section stained with toluidine blue. (C) Adhesion of the glomerular tufts to the Bowman's capsule with segmental sclerosis in the kidney of a 24-week old rat. PAS staining. Scale bars = 50 µm.

• 

  Fig. 2 (A) Severe podocyte foot process (FP) effacement with rearrangement of the actin cytoskeleton (arrows) over broad areas of the glomerular basement membrane (GBM) in a 9-week old male OM rat. (B) FPs anchoring the GBM (*) in close contact with one another or adhered (arrows) with dislocation of the slit membrane in a 6-week old OM rat. Arrowhead indicates the slit membrane. (C) Osmiophilic lysosomes (*) and flattened podocytes (arrows) in a 24-week old male OM rat. CL: capillary lumen, E: endothelial cell, FP: foot process, PC: podocyte. Scale bars = 1 µm (A and B) and 3 µm (C).

• 

  Fig. 3 (A) Denuded GBM (arrows) resulting from FP detachment in a 24-week old male OM rat. (B) An electron-dense matrix (*) formed a bridge between the denuded GBM (arrow) and parietal epithelial cells rich in polysomes and rough endoplasmic reticula in a 24-week old male OM rat. A degenerated podocyte is shown on the left side. (C) Prominent splitting or lamination of the GBM (*) in a 6-week old male OM rat. BS: Bowman's space, CL: capillary lumen, E: endothelial cell, FP: foot process, PC: podocyte, PE: parietal epithelial cell. Scale bars = 3 µm (A) and 1 µm (B and C).

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