The Rowett rat strain is resistant to renal fibrosis.

BACKGROUND: Genetic susceptibility to renal fibrosis may determine the individual rate of progression to renal failure. We aimed to study the progression in Rowett (RO) rats, a strain we found resistant to subtotal nephrectomy (SNX), comparing to Sprague-Dawley (SD) rats, a strain with established sensitivity in a radical ablation/infarction and diet-induced SNX model. METHODS: Eight-week-old male RO (RO-SNX) and SD (SD-SNX, n = 5/group) rats underwent SNX and were kept on high protein and salt diet. Kidney function was monitored and the kidneys were evaluated by histology and immunohistochemistry 5 weeks after SNX. RESULTS: RO-SNX rats had only mild proteinuria and less glomerulosclerosis, accompanied by less fibronectin and TGF-beta staining as compared to SD-SNX rats. Glomerular nitrotyrosine staining was less intense in RO-SNX vs SD-SNX, accompanied by less podocyte damage as demonstrated by desmin staining. CONCLUSION: Our results demonstrate the importance of podocyte damage in glomerulosclerosis and that Rowett rats are protected from renal fibrosis. To our knowledge, this is the first strain of rats with unknown genetic resistance, which makes the strain attractive for studying the genetic background of renal fibrosis.