The interest evoked by the Broad Breasted White Turkey (BBWT) as an animal model for studying the cardiovascular damages produced by
hypertension and
catecholamines is mainly due to the fact that
hypertension is spontaneous and tissue and circulating
catecholamines, especially
norepinephrine, are extremely high. In this paper we focused our attention on three characteristic pathophysiological features displayed by these animals which are strictly related, as well as in humans, to the elevated blood pressure values and to
catecholamine action. We also described the possibility of modifying the development of some of these lesions with pharmacological interventions liable to antagonize the peripheral effects of
norepinephrine and
epinephrine. The
dissecting aneurysm of the aorta accounts for 5-10% of sudden deaths in this animal strain. It can be prevented by lowering blood pressure, especially with beta-blockers, and facilitated by
MAO-inhibitors. The degree of
cardiac hypertrophy is remarkably high and unexpectedly characterized by the synthesis of a "fast" V1-like isomyosin with high Ca++ activated
ATPase activity, oxygen consumption and speed of muscle shortening. Neither the reduction of the degree of
cardiac hypertrophy, nor treatment with
labetalol alone were able to modify this peculiar pattern. In spite of having very high levels of
high-density-lipoproteins, which are known to be protective against
atherosclerosis, this animal develops a severe atheromatous disease especially in the abdominal aorta, where the cellular growth has also been proven to be in vitro more pronounced than in the thoracic tract. Treatment with beta-blockers reduced the severity and extent of the lesion even in absence of a significant reduction in blood pressure.