Spontaneously hypercholesterolemic (SHC) rats aged 6 to 26 weeks were examined histological ly. The earliest lesion, observed in the kidney of 6-week-old animals, was a deposition of proteinous reabsorptive droplets in the glomerular epithelial cells. An increase of reabsorptive droplets and the adhesion of glomerular tufts to Bowman's capsules were observed at 8 weeks of age. Thereafter, the renal lesions progressively deteriorated and the animals developed severe focal glomerular sclerosis,

more »

... companied by severe tubular degeneration. In 26-week-old SHC rats, marked hypertrophy of the parathyroid gland was found accompanyied by severe calcification in soft tissues such as cardiac muscle, the pulmonary alveolar septum, the gastric mucosal wall and vascular wall. These findings suggest that SHC rats initially develop an increase of glomerular permeability which is followed by progressive focal glomerular sclerosis with advancing age and then results in secondary hyperparathyroidism and severe metastatic calcification in soft tissues.