The role of the mononuclear phagocyte in primate and rabbit models of atherosclerosis

The involvement of the monocyte/macrophage in the early stages of the atherogenic process has been recognized and documented for many years. Early animal studies with the cholesterol-fed rabbit (1) and rats (2), and more recent studies with hypercholesterolemic swine (3, 4) and rats (5) have observed: monocytes adherent to the endothelium in vascular tissue, both prior to and following the development of atherosclerotic lesions, monocytes penetrating through the endothelium, resident in the intima, and possibly exiting the artery as lipid-laden foam cells. However, to date, the question remains as to whether the monocyte/macrophage plays a role in the transition from the macrophage-rich fatty streak to the smooth muscle proliferative lesion. Studies by Faggiotto, et al. (6, 7) with the nonhuman primate, Macaca nemestrina, provide evidence that the monocyte/macrophage does play a role in this transition.