TY - JOUR
T1 - Thyrotropin modulates receptors for atrial natriuretic peptide on intact human thyroid cells
AU - Tseng, Y. C.L.
AU - Sellitti, D. F.
AU - Ahmann, A. J.
AU - Burman, K. D.
AU - D'Avis, J. C.
AU - Wartofsky, L.
N1 - Funding Information:
From the Departments of *Clinical Investigation, tSurgery and ~Medicine, Walter Reed Army Medical Center, Washington, DC, and Uniformed Services University of the Health Sciences, Bethesda, Maryland. This project was supported by the Department of Clinical I nvestigation, Walter Reed Army Medical Center, Protocol No. 1399-87. Presented in part at the annual meeting of the American Society for Clinical Investigation, Washington, DC, May 1988. The authors acknowledge the administrative support of Mr. Mack Burton and the editorial assistance of Mrs. Estelle C. Coleman. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. Reprint requests: Dr. Leonard Wartofsky, Endocrine-Metabolic Service, 7D, Walter Reed Army Medical Center, Washington, DC 20307-5001.
PY - 1989
Y1 - 1989
N2 - Interest in the mechanism of impaired salt and water metabolism in hypothyroidism has led to growing evidence of an interaction between atrial natriuretic peptide (ANP) and the thyroid, which includes reports of direct effects of thyroid hormone on ANP synthesis and circulating ANP levels, and of the presence of specific ANP receptors in human thyroid tissue, which may act to inhibit thyroglobulin (Tg) secretion. The authors questioned whether or not thyrotropin (TSH) has a role in this interaction. They used 125I-ANP to study the effect of TSH on ANP binding to human thyroid cells in primary culture. Binding competition by increasing concentrations of unlabeled ANP in the presence or absence of TSH was assessed by Scatchard analysis. At lower temperatures of 4°C or 23°C, TSH had no effect either on the ANP receptor equilibrium dissociation constant (Kd) or number of binding sites. However, at 37°C, bovine TSH at 1 mU/ml reduced measurable binding sites by about 50% without affecting receptor affinity (Kd = 0.2 nM). Prolonged (6 days) coincubation of TSH with thyroid cells decreased the assayable ANP receptor. The effects of TSH appear to be specific because human luteinizing hormone, follicle-stimulatory hormone, growth hormone, human chorionic gonadotropin and iodide had no effect on ANP binding. Thus, human thyroid cells possess a single class of high-affinity, specific receptors for ANP with binding activity that is temperature dependnet and modulated by TSH at physiologic temperature. TSH-mediated reduction of binding at 37°C but not at 4°C suggests an energy-dependent process that acts possibly by activating an ANP degradative enzyme or by changing the rate of receptor internalization and subsequent degradation.
AB - Interest in the mechanism of impaired salt and water metabolism in hypothyroidism has led to growing evidence of an interaction between atrial natriuretic peptide (ANP) and the thyroid, which includes reports of direct effects of thyroid hormone on ANP synthesis and circulating ANP levels, and of the presence of specific ANP receptors in human thyroid tissue, which may act to inhibit thyroglobulin (Tg) secretion. The authors questioned whether or not thyrotropin (TSH) has a role in this interaction. They used 125I-ANP to study the effect of TSH on ANP binding to human thyroid cells in primary culture. Binding competition by increasing concentrations of unlabeled ANP in the presence or absence of TSH was assessed by Scatchard analysis. At lower temperatures of 4°C or 23°C, TSH had no effect either on the ANP receptor equilibrium dissociation constant (Kd) or number of binding sites. However, at 37°C, bovine TSH at 1 mU/ml reduced measurable binding sites by about 50% without affecting receptor affinity (Kd = 0.2 nM). Prolonged (6 days) coincubation of TSH with thyroid cells decreased the assayable ANP receptor. The effects of TSH appear to be specific because human luteinizing hormone, follicle-stimulatory hormone, growth hormone, human chorionic gonadotropin and iodide had no effect on ANP binding. Thus, human thyroid cells possess a single class of high-affinity, specific receptors for ANP with binding activity that is temperature dependnet and modulated by TSH at physiologic temperature. TSH-mediated reduction of binding at 37°C but not at 4°C suggests an energy-dependent process that acts possibly by activating an ANP degradative enzyme or by changing the rate of receptor internalization and subsequent degradation.
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U2 - 10.1097/00000441-198907000-00003
DO - 10.1097/00000441-198907000-00003
M3 - Article
C2 - 2546425
AN - SCOPUS:0024397421
SN - 0002-9629
VL - 298
SP - 15
EP - 19
JO - American Journal of the Medical Sciences
JF - American Journal of the Medical Sciences
IS - 1
ER -