THYROID-HORMONE ACTION AT THE CELL LEVEL .2.

(Second of Two Parts) Inter-relation between Thyroid Hormone, Catecholamines and β-Adrenergic Receptors Previous speculation and many data in this area are omitted for the sake of brevity. Some of the manifestations of clinical thyrotoxicosis resemble excessive adrenal medullary activity. Moreover, the β-adrenergic blocking agent, propranolol, has been successfully employed in the management of some manifestations of thyrotoxicosis.91 It is therefore appropriate to mention recent findings suggesting an increased number of β-adrenergic receptor sites in the cardiac plasma membranes of experimental hyperthyroid rats.92 93 94 Cardiac membranes (in a mixture including microsomes) from rats rendered toxic with excess thyroid hormone exhibited an increased. © 1979, Massachusetts Medical Society. All rights reserved.