A new murine model of autosomal recessive polycystic kidney disease.

We describe the renal cystic disease occurring in a new inbred strain of mice which developed as a spontaneous mutation in otherwise healthy Balb/c mice. The disease displays characteristics of an autosomal recessive polycystic kidney disease. Affected animals develop massive cystic enlargement of the kidneys and die of renal failure at the age of 4 weeks. During postnatal development, there is a gradual shift in site of the lesions. At birth, cystic dilations are localized almost exclusively in proximal tubular segments, whereas in the terminal stages of the disease, 80% of the cysts are localized in collecting tubular segments as defined by segment specific lectin binding. The composition of the basement membrane of the cystic tubular walls during postnatal development as analyzed by immunocytochemistry is essentially normal during the earliest stage of cyst formation. However, with disease progression, the cystic tubular basement membrane demonstrates a decreased immunoreactivity to anti-laminin and anti-entactin antibodies. This indicates a shift in cyst localization during disease progression in this model, and suggests that basement membrane abnormalities are not a primary feature of the early cyst formation and progressive enlargement.