Related Experiment Video
Updated: Jun 12, 2026
An Efficient Sieving Method to Isolate Intact Glomeruli from Adult Rat Kidney
Published on: November 1, 2018
Early-onset podocyte injury and glomerular sclerosis in osborne-mendel rats
Kyohei Yasuno1, Shoko Ishihara, Rio Saito
1Research Institute of Biosciences, Azabu University, Kanagawa, Japan.
Abstract:
Progressive glomerular injury associated with early-onset proteinuria was investigated in male Osborne-Mendel (OM) rats aged 5 to 20 weeks. Age-matched male Fischer 344 (F344) rats were used for comparison. OM rats developed mild hypertension and selective proteinuria (albuminuria) from 5 weeks of age, and non-selective proteinuria from 7 weeks of age. Light microscopy of OM kidney revealed hyaline droplets in the podocyte at 5 weeks of age and vacuolation of podocytes and adhesion of the capillary loop to the Bowman's capsule at 7 weeks of age. Segmental glomerulosclerosis developed in OM rats from 15 weeks of age, and global sclerosis appeared at 20 weeks of age. Desmin, a marker of podocye injury, was expressed in podocytes from 10 weeks of age, and the intensity of expression increased with age. Ultrastructurally, damage to podocytes such as effacement of foot processes, decreasing number of filtration slits, and rearrangement of the actin cytoskeleton were observed from 5 weeks of age in OM rat. Glomerular volume in OM rats increased with age and was consistently higher than in age-matched F344 rats. The number of WT-1-positive podocytes and vimentin-positive podocyte area were lower in OM rats and decreased with age. These findings suggest that glomerulonephropathy in male OM rats is associated with glomerular hypertrophy, progressive podocytopathy, and a reduction in podocyte number and area. Renal injury in OM rats was associated with development of early-onset proteinuria and was more progressive than in age-matched F344 rats.
Insights
Male Osborne-Mendel rats exhibit progressive kidney injury, developing early proteinuria and podocyte damage. This glomerulonephropathy is characterized by glomerular hypertrophy and reduced podocyte count, indicating a more severe renal disease progression compared to Fischer 344 rats.
Area of Science:
- Nephrology
- Pathology
- Animal Models
Background:
- Osborne-Mendel (OM) rats show early-onset proteinuria and hypertension.
- Fischer 344 (F344) rats serve as a control group for comparison.
- Understanding progressive glomerular injury is crucial for kidney disease research.
Purpose of the Study:
- To investigate progressive glomerular injury and early-onset proteinuria in male OM rats.
- To characterize the pathological changes in OM rat kidneys over time.
- To compare renal injury progression between OM and F344 rats.
Main Methods:
- Light and electron microscopy of kidney tissues from OM and F344 rats (5-20 weeks).
- Assessment of proteinuria (albuminuria) and hypertension.
- Immunohistochemical analysis for podocyte markers (Desmin, WT-1, vimentin).
Main Results:
- OM rats developed selective and non-selective proteinuria, hypertension, and glomerular hypertrophy.
- Podocyte injury (vacuolation, foot process effacement) and glomerulosclerosis were observed in OM rats.
- Reduced podocyte number (WT-1 positive) and area (vimentin positive) were noted in OM rats, decreasing with age.
Conclusions:
- Glomerulonephropathy in male OM rats is linked to glomerular hypertrophy and progressive podocytopathy.
- A reduction in podocyte number and area contributes to renal injury in OM rats.
- OM rats demonstrate a more progressive renal injury model compared to F344 rats, with early-onset proteinuria.
