Coronary arterial abnormalities in hyperlipidemic rats with renal failure.

Hyperlipidemic rats, which have been described as a useful animal model for focal glomerulosclerosis in humans, were examined at the ages of 17, 20, 24, and 27 weeks for evaluation of spontaneously developed coronary arterial lesions. The mean concentrations of cholesterol, triglyceride, phospholipid, and urea nitrogen were greater than the respective control concentrations at and after the age of 17 weeks. No abnormalities were detected in the blood pressure values. Starting from the age of 24 weeks, the rats had disseminated white spots in the ventricles and septum of the heart. Mean renal weights of hyperlipidemic rats were higher than those of control rats at the ages of 17 and 20 weeks, and the surface of the kidney appeared irregular when rats were 27 weeks old. Histologic examination revealed atrophy of the coronary artery, a decrease in the number of smooth muscle cells, and thinning of the wall, resulting in loss of the normal wall structure. A homogenous eosinophilic substance, the nature and cause of which were unknown, was also seen in the affected arterial walls. Furthermore, white spots observed macroscopically were found to represent myocardial degeneration and necrosis with reactive histiocytic cells and lymphocytes, adventitial fibrosis, and edema associated with the affected arteries. These arterial lesions became evident in rats at and after the age of 24 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)