Differential Regulation of Beta-Adrenergic Receptor-Coupled Adenylate Cyclase by Thyroid Hormones in Rat Liver and Heart: Possible Role of Corticosteroids
- 1 January 1987
- journal article
- research article
- Published by S. Karger AG in Hormone Research
- Vol. 27 (2), 109-118
- https://doi.org/10.1159/000180796
Abstract
Thyroid hormone regulation of β-adrenergic receptor-coupled adenylate cyclase activity was studied in rat liver and heart particulate fractions. Thyroidectomy (Tx) increased isoproterenol-stimulated cAMP accumulation in the liver and decreased it in the heart. Administration of L-thyroxine (L-T4) or L-3,3′,5-triiodothyronine (L-T3) reversed these changes in both liver and heart. The changes observed in liver β-receptor-coupled adenylate cyclase activity after Tx were similar to those reported after adrenalectomy (ADX). Thus the hypothesis was considered that these changes with altered thyroid status are produced indirectly through alteration in adrenal corticosteroids. Hydrocortisone in Tx rats decreased liver isoproterenol-stimulated adenylate cyclase activity but had no significant effect on the heart. Serum corticosterone levels were decreased significantly (by 34%) in Tx rats, as compared to euthyroid rats. Administration of L-T4 to Tx rats doubled the serum corticosterone levels. In Tx-ADX rats, L-T4 had no significant effect on liver β-receptor-coupled adenylate cyclase. However, L-T4 significantly increased heart β-receptor-coupled adenylate cyclase in these animals. Dexamethasone, but not deoxycorticosterone, decreased liver isoproterenol-stimulated cAMP accumulation in Tx animals to the same extent as was observed with L-T4 and hydrocortisone. Thus overall the results indicate that in the liver, as opposed to the heart, thyroid hormones regulate β-adrenergic receptor-coupled adenylate cyclase indirectly through corticosteroids. Glucocorticoid rather than mineralocorticoid activity seems to be responsible for this regulation.Keywords
This publication has 20 references indexed in Scilit:
- Characterization with [3H] dihydroergocryptine of the alpha-adrenergic receptor of the hepatic plasma membrane. Comparison with the beta-adrenergic receptor in normal and adrenalectomized ratsJournal of Biological Chemistry, 1978
- Changes in the sarcolemma of the hypothyroid heartBiochemical and Biophysical Research Communications, 1978
- β-Adrenergic receptors in rat heart: Effects of thyroidectomyEuropean Journal of Pharmacology, 1977
- Thyroid hormone regulation of beta-adrenergic receptor number.Journal of Biological Chemistry, 1977
- Thyroxine and propylthiouracil effects in vivo on alpha and beta adrenergic receptors in rat heartBiochemical and Biophysical Research Communications, 1977
- beta-adrenergic receptors in rat liver: effects of adrenalectomy.Proceedings of the National Academy of Sciences, 1976
- Secretion of Aldosterone by Adrenal Glands of Propylthiouracil-Treated RatsEndocrinology, 1965
- Aldosterone Secretion and Metabolism in Hyperthyroidism and Myxedema1Journal of Clinical Endocrinology & Metabolism, 1963
- THE INFLUENCE OF THE THYROID ON ADRENAL CORTICAL FUNCTIONJCI Insight, 1958
- PROTEIN MEASUREMENT WITH THE FOLIN PHENOL REAGENTJournal of Biological Chemistry, 1951