[A study of an autosomal recessive polycystic kidney disease with facial and skeletal abnormalities in rat].

Clinico-pathological studies were made on rats with polycystic kidney disease (PCK), a congenital renal disorder transmitted as an autosomal recessive trait and characterised by facial and skeletal anomalies, with the results summarised as follows: 1) Affected animals had a poor weight gain and slightly increased urinary excretion of low molecular weight protein from 2 months after birth, and developed polyuria and hypocalciuria 5 months postnatally. They had elevation of serum urea nitrogen, increased urinary excretion of urea nitrogen and hypoproteinemia 8 months postnatally though without showing elevated serum creatinine and died around 10 months of life. 2) Kidneys of chin rats appear granular in surface, enlarge little by little while preserving the entire kidney morphology; a small cyst is formed in the renal medulla 2 months postnatally, then enlarges gradually to encroach upon the cortex and grows to involve all cortical layers by 8 months of life. This cyst was revealed by lectin staining to be derived from the collecting ducts and was assumed to correspond, both morphologically and clinically, to the infantile or juvenile form of PCK in humans. Pathogenetic factors of the characteristic facies and skeletal abnormalities were also investigated.