Thyroid hormone regulation of beta-adrenergic receptor number.

Published

Journal Article

The effects of exogenous thyroid hormones (thyroxine and triiodothyronine) on beta-adrenergic receptors in the rat myocardium were investigated. The potent beta-adrenergic antagonist, (-)-[3H]dihydroalprenolol, was used to directly estimate the number and affinity of beta-adrenergic receptors in rat heart membranes from control and hyperthyroid rats. Cardiac membranes from hyperthyroid rats contained 196 +/- 7 fmol of (-)-[3H]dihydroalprenolol binding sites/mg of protein which was significantly (p less than 0.005) greater than the number of binding sites (89 +/- 5 fmol/mg of protein) present in control membranes. The equilibrium dissociation constant (KD) for the interaction of receptors with dihydroalprenolol was the same (2 to 15 nM) in membranes from control and hyperthyroid rats. Similarly, there was no significant difference between the control and hyperthyroid membranes in the affinity of the beta-adrenergic receptor binding sites for the beta-adrenergic agonist isoproterenol. The results of this study demonstrate that thyroid hormones can regulate the number of cardiac beta-adrenergic receptors. The increased numbers of receptors may be responsible, at least in part, for the enhanced catecholamine sensitivity of beta-adrenergic-coupled cardiac responses in the hyperthyroid state.

Full Text

Duke Authors

Cited Authors

  • Williams, LT; Lefkowitz, RJ; Watanabe, AM; Hathaway, DR; Besch, HR

Published Date

  • April 25, 1977

Published In

Volume / Issue

  • 252 / 8

Start / End Page

  • 2787 - 2789

PubMed ID

  • 15999

Pubmed Central ID

  • 15999

International Standard Serial Number (ISSN)

  • 0021-9258

Language

  • eng

Conference Location

  • United States