Effect of thyroid hormone on myocardial catecholamine content of the guinea pig

Abstract

Normal and thyroidectomized guinea pigs were subjected to treatment with either triiodothyronine or thyroid-stimulating hormone. Determinations of myocardial catecholamine content and serum protein-bound iodine revealed a significant increase in myocardial norepinephrine content in the markedly thyrotoxic animal, and a significant decrease in norepinephrine content of the myocardium of hypothyroid animals. The significance of these findings in defining the role of catecholamines in various states of thyroid function is discussed.