Histopathology of arterial lesions in LPA transgenic mice on cholesterol-enriched chow

The aortic root from 21 LPA transgenic mice and 18 control litter mates on cholesterol enriched chow were studied histologically for the presence of a therosclerotic lesions. Serial sections were cut and the total area of the lesions was measured by use of computerised image analysis. Lipid staining lesions were found in 17 aortas of the transgenic mice and were five times more common than in the controls. Foam cell lesions were the only type of l esion in 12 of the aortas from transgenic animals, while five animals had d eveloped fibrofatty lesions. Immunostaining revealed monocytes/macrophages on the endothelial surface, and in the subendothelial space of foam cell le sions. In fibrofatty lesions, spindle shaped cells formed a cap around the lipid core. This study supports the view that transgenic mice expressing hu man apolipoprotein (a) on a high fat and cholesterol diet, are more suscept ible to aortic lesions than control mice and develop early atherosclerotic lesions comparable to lesions in man. Aminoguanidin in the drinking water h ad no effect on the aortic lesions, but lesion size was significantly, nega tively correlated with plasma glucose concentration. (C) 2000 Elsevier Scie nce Ireland Ltd. All rights reserved.