Observations in New England Deaconess Hospital rats harboring pheochromocytoma

Pheochromocytomas are rare tumors, typically found in the adrenal medulla, which may secrete large quantities of catecholamines such as dopamine, norepinephrine, and epinephrine. Pheochromocytomas are usually associated with hypertension, which may be severe. Relatively little is known about the cardiovascular manifestations of pheochromocytoma because of the rarity of the disease and the difficulty of ethically studying patients with this explosive and potentially lethal disease. New England Deaconess rats (a Wistar-derived strain) harbor a transplantable pheochromocytoma which has many features reminiscent of the human disease. These rats develop markedly elevated concentrations of norepinephrine that are associated with severe hypertension, desensitization of alpha and beta adrenergically mediated responses, and catecholamine-induced cardiomyopathy. This paper briefly reviews work undertaken in the author's laboratory on the mechanisms of these alterations in the cardiovascular system of rats harboring pheochromocytoma.