The occurrence of microthrombi on the aortic endothelium of swine.

Evidence is presented in this report that microthrombi composed chiefly of platelets form on what appears to be morphologically normal swine endothelium and that the pattern of the deposits corresponds to that in analogous flow-chamber models, and to the lesions in the early stages of swine atherosclerosis. Since mural thrombi occur in young swine, it seems reasonable to suggest that this is to some extent a normal process. The cumulative effects of such a process could be a factor in the primary as well as the late stages of atherosclerosis.