Atherosclerosis following balloon catheter injury to the carotid artery and the aorta of hypertensive rats with normolipidemia or hyperlipidemia.

The carotid artery and abdominal aorta of hypertensive normocholesterolemic rats responded in similar manner to balloon denuding of the endothelium. One denuding resulted in an intimal fibrous plaque, while multiple such injuries increased the lipid content of the plaque and so yielded fatty-fibrous plaques, which perhaps represent an intermediate stage of atherosclerosis. In no instance did a single or multiple denuding lead to advanced atherosclerosis. Although the abdominal aorta of animals with one or with repeated denudings accumulated more lipid when placed on atherogenic died, the lesions remained essentially in the fatty-fibrous plaque category. Typical atherosclerosis was observed only occasionally and was limited to rats with multiple denudings. In rats with denuded carotid artery on an atherogenic diet classic atherosclerosis developed, especially when there were multiple episodes of injury. This was the first time the authors observed advanced atherosclerosis in the rat, and the lesions were quite comparable to human atherosclerosis. For the rat in this instance the principal factors in pathogenesis were hyperlipidemia and the repeated endothelial denudings, which promoted lipid deposit in the intimal plaques of the vessel.