Renal changes in experimental hypercholesterolemia in normal and in subdiabetic rabbits. II. Long term studies
Wellmann, K.F.; Volk, B.W.
Laboratory Investigation; a Journal of Technical Methods and Pathology 24(2): 144-155
1971
ISSN/ISBN: 0023-6837 PMID: 5542735 Document Number: 43136
For part 1 see Abst. 7557, Vol. 40. 2. Of 45 adult male white New Zealand rabbits, 23 untreated and 17 subdiabetic rabbits were given a diet containing 1% cholesterol for periods of 2 months alternating with 2-month periods in which no cholesterol was added, for from 6 to 12 months. Five untreated rabbits served as normal controls. Subdiabetes was induced by injection of small quantities of alloxan alone or by sequential injections of cortisone and alloxan; it is characterized by the development of hyperglycaemia, with blood sugar 190 mg/100 ml and higher, only after repeated injections of small doses of cortisone which would normally not induce diabetes. Although the subdiabetic rabbits showed higher blood lipids than the metabolically normal rabbits, both before and shortly after the first few months of cholesterol administration, the differences tended to disappear with continued cholesterol intake, blood lipids remaining abnormally high in both groups. Creatinine and blood urea N values remained within the normal range both before and after addition of cholesterol to the diet. Detailed histological examinations were made of kidneys and results are described and shown in plates. With Oil Red O and Sudan Black renal foam-cell plaques were seen below the corticomedullary junction in almost all the treated rabbits. The incidence of medium-sized and large plaques was the same in normal and in subdiabetic animals, in contrast to the findings in the short study (part 1) in which large plaques occurred much more frequently in subdiabetic animals. Linear cortical scars and, more rarely, small mononuclear cell collections were seen above the foam cell plaques in a number of rabbits. Glomerular lesions were seen in 30% of the normal and 24% of the subdiabetic rabbits; glomerular capillary basement membrane thickening and flattening of glomerular epithelial cell foot processes were occasionally seen. Many renal tubular cells contained lipid inclusions and some had assumed the appearance of foam cells. Initial foam cell plaques were identified in renal artery branches in 17% of the normal and 41% of the subdiabetic animals.