MONKEYS, AGGRESSION, AND THE PATHOBIOLOGY OF ATHEROSCLEROSIS

Although it is frequently hypothesized that psychosocial factors influ ence the development of coronary heart disease and the underlying athe rosclerosis, evidence directly supporting this hypothesis or identifyi ng the mediating mechanisms has been sparse at best. The present artic le reviews research designed to elucidate the role of behavior in the pathogenesis of atherosclerosis (and thus coronary heart disease). Par ticular emphasis is placed on experimental evidence linking atheroscle rosis to both behavior and sympathoadrenal activation in cynomolgus ma caques (Macaca fascicularis). In males of this monkey species, behavio ral dominance and aggression interact with social instability to promo te the development of diet-induced atherosclerosis. Beta-adrenorecepto r blockade prevents this behavioral exacerbation of atherosclerosis, s uggesting a mechanism of sympathetic origin. Furthermore, independentl y of social rank or environmental perturbation, animals exhibiting a h eightened cardiac responsivity to stress are excessively aggressive an d also develop the most extensive coronary lesions. Taken together, th ese experimental data strongly implicate aggressiveness and sympatheti c arousal, occurring as a result of either inherent hypersensitivity o r environmental stimulation, in the pathogenesis of atherosclerosis. A dditional data suggest that a specific neurotransmitter complex-the se rotonergic (5-hydroxytryptamine) system-modulates factors associated w ith the expression of social dominance and exaggerated heart rate reac tivity, perhaps thereby explaining a portion of variable susceptibilit y to atherosclerosis and coronary heart disease. (C) 1998 Wiley-Liss, Inc.