Increased Levels of Plasma Noradrenaline in Hypothyroidism

Abstract

Plasma catecholamine concentration was measured in hypothyroid and hyperthyroid subjects employing a precise and sensitive double-isotope derivative technique. In the hypothyroid subjects, plasma noradrenaline was increased approximately three-fold in the supine position compared to normals. No change was observed in plasma adrenaline. The plasma catecholamine concentration was also elevated in the hypothyroid subjects in the standing position. After treatment with thyroxine the values returned to normal. The hyperthyroid patients exhibited lower plasma noradrenaline values than in the controls but the difference was not significant.