Role of Hyperplasia in Vascular Lesions of Cholesterol-fed Rabbits Studied with Thymidine-H 3 Autoradiography

Rabbit aorta and coronary vessels were studied with thymidine-H3 and autoradiography. They were found to comprise an extremely stable population of cells, the latter probably even more stable than the former. Compensatory repair by means of regeneration at sites of bifurcation seems inadequate. This in part may explain the susceptibility of these areas to the development of atherosclerotic lesions. Proliferation, although sequentially secondary to fatty infiltration, plays an active role in the pathogenesis of cellular atherosclerotic lesions as seen in the rabbit. Foam cells possess the ability to synthesize DNA even when incorporated within the atherosclerotic lesion. Arguments in support of and opposed to some of the current hypotheses for the pathogenesis of atherosclerosis have been presented.