Peripheral Circulatory and Metabolic Consequences of Thyrotoxicosis: III. Vascular reactivity to catecholamines and the effect of sympathetic receptor blockade on blood flow and oxygen consumption of skeletal muscle in experimental thyrotoxicosis in the dog

Abstract

Frey, H. M. M. Peripheral Circulatory and Metabolic Consequences of Thyrotoxicosis. III. Vascular reactivity to catecholamines and the effect of sympathetic receptor blockade on blood flow and oxygen consumption of skeletal muscle in experimental thyrotoxicosis in the dogs. Scand. J. din. Lab. Invest. 19, 132-142, 1967. The resistance vessels of the gracilis muscle in the anesthetized, thyrotoxic dog responded in the majority of cases to smaller doses of intra-arterially infused catecholamines than did those of normal controls. The increased sensitivity comprised both alpha- and beta-receptor functions, with some indication that it was slightly more pronounced for beta-receptors.Following sympathetic receptor blockade with Phenoxybenzamine and/or Inderal, a reduction of cardiac output ensued which was of the same relative magnitude in normal and thyrotoxic dogs. Blood flow through the gracilis muscle was reduced in both groups in proportion to the fall in cardiac output.Sympathetic receptor blockade did n...