Chronic Nephropathy

A syndrome resembling chronic progressive nephropa­thy (CPN) in aged rats occurs in aged mice. It is also referred to as interstitial nephritis or chronic nephritis. CPN has been specifically described in B6C3F1 mice but occurs commonly in other strains. The pathogenesis is not known, but it features glomerular hyalinosis, glo­merulosclerosis, tubular degeneration, regeneration, interstitial inflammation, and dilated tubules with pro­tein-rich fluid in their lumina (Figs. 1.120). Advanced cases have irregular pitting of the renal cortices and uremic syndrome. Anemia and ascites may be present in advanced cases, but metastatic calcification of tissues is usually not a feature of renal disease in the mouse.