CHANGES IN MEMBRANE POTENTIAL OF CULTURED PORCINE AND HUMAN THYROID CELLS IN RESPONSE TO THYROTROPHIN AND OTHER AGENTS

1981 ◽  
Vol 88 (2) ◽  
pp. 187-NP ◽  
Author(s):  
J. R. BOURKE ◽  
K. L. CARSELDINE ◽  
S. H. FERRIS ◽  
G. J. HUXHAM ◽  
S. W. MANLEY
Keyword(s):  
Membrane Potential ◽  
Cyclic Amp ◽  
Human Thyroid ◽  
Resting Membrane Potential ◽  
Prostaglandin E ◽  
Follicular Cells ◽  
Thyroid Cells ◽  
Enhanced Sensitivity ◽  
Long Acting ◽  
Cells Cultured

Thyrotrophin (TSH), cyclic AMP, cyclic GMP and 1-methyl-3-isobutyl-xanthine (MIX) promoted the reassociation of isolated porcine and human thyroid cells into follicular structures in culture and stimulated the uptake of radio-iodide. Monolayer cells were present in all cultures, but in decreasing proportions as the concentration of stimulator was increased. The resting membrane potential of porcine thyroid cells cultured for 4 days in the presence of TSH was −54 ± 3·6 (mean ± s.d.) mV for follicular cells and −31 ± 2·6 mV for monolayer cells. In the absence of TSH, only monolayer cells were present and their membrane potential was −24 ± 2·0 mV. Removal of hormone by washing resulted in hyperpolarization to −70 ± 2·9 mV (follicular cells) or −59 ± 3·4 mV (monolayer cells). Subsequent replacement of TSH, or addition of cyclic AMP, MIX, prostaglandin E1 (PGE1) or long-acting thyroid stimulator immunoglobulin resulted in depolarization of previously hyperpolarized cells, to approximately the membrane potential observed before washing. Incubation in MIX resulted in enhanced sensitivity to the depolarizing effect of TSH. Cells cultured in the absence of TSH were unresponsive to TSH or other stimulators. The membrane potential of human thyroid cells behaved similarly in response to TSH, to hormone removal and replacement, and to MIX and PGE1.

Water and electrolyte contents, cell pH and membrane potentials of cultured turtle thyroid cells

1985 ◽  
Vol 104 (1) ◽  
pp. 45-52 ◽  
Author(s):  
S. Y. Chow ◽  
Y. C. Yen-Chow ◽  
D. M. Woodbury
Keyword(s):  
Membrane Potential ◽  
Cell Membrane ◽  
Culture Medium ◽  
Resting Membrane Potential ◽  
Follicular Cells ◽  
Iodide Uptake ◽  
Thyroid Cells ◽  
Cell Ph ◽  
Cells Cultured ◽  
In Cells

ABSTRACT Water and electrolyte contents, cell pH, membrane potential and 125I− uptake were determined in cultured follicular cells of turtle thyroid. The Na+, K+ and Cl− concentrations in the cultured thyroid cells were 59·2, 119·0 and 50·9 mmol/l cell water respectively. Treatment with TSH (10 mu./ml for 24 h) increased the K+ and Cl− and decreased the Na+ concentrations in cells. The water and protein contents of these cells were 81·6 and 8·7 g/100 g cells respectively. The cell pH was 6·91. With glass microelectrodes, the resting membrane potential of thyroid cells cultured in Medium 199 averaged 33·9 ± 0·63 mV which is slightly higher than 29·8 ± 1·6 mV as calculated from the data on the uptakes of [14C]methyltriphenylphosphonium and 3H2O by the cells. The potential varied linearly with the log of external K + concentration (between 15 and 120 mmol/l) with a slope of about 24 mV per tenfold change in K+ concentration. Both TSH and cyclic AMP depolarized the cell membrane. Calculations based on the values for the electrolyte concentrations in cells and in culture medium indicated that Na+, K+ and Cl− were not distributed according to their electrochemical gradients across the cell membrane. Na+ was actively transported out of the cells and K+ and Cl− into the cells. Follicular cells of turtle thyroid cultured in the medium without addition of TSH formed a monolayer. Their iodide-concentrating ability was low and they did not respond to TSH with an increase in iodide uptake. In contrast, cells cultured in medium containing TSH tended to aggregate and organize to form follicles. They had higher ability to concentrate iodide and respond to TSH. J. Endocr. (1985) 104, 45–52

Electrical responses of cultured thyroid cells to serotonin

1985 ◽  
Vol 107 (3) ◽  
pp. 397-401 ◽  
Author(s):  
P. A. McGrath ◽  
J. R. Bourke ◽  
G. J. Huxham ◽  
S. W. Manley
Keyword(s):  
Membrane Potential ◽  
Cyclic Amp ◽  
Resting Membrane Potential ◽  
Previous Exposure ◽  
Dibutyryl Cyclic Amp ◽  
Thyroid Cells ◽  
Adrenoceptor Agonist ◽  
Electrical Responses

ABSTRACT Cultured porcine thyroid cells, maintained in the differentiated state by dibutyryl cyclic AMP, responded to serotonin (5-HT; 10 nmol/l to 1 μmol/l) with a depolarization of the membrane potential, but did not respond to histamine (100 μmol/l) or dopamine (1 μmol/l). The resting membrane potential of these cells was about − 71 mV, maximal concentrations of 5-HT (1 μmol/l) inducing a depolarization to approximately −53 mV. Methysergide or phenoxybenzamine, but not propranolol, abolished the response to 5-HT. Sensitivity to 5-HT was reduced by previous exposure of cultures to TSH, the β-adrenoceptor agonist salbutamol or 5-HT itself. J. Endocr. (1985) 107, 397–401

Studies of catecholamine effect on cyclic AMP in human cultured thyroid cells: their interaction with thyrotrophin receptor

1983 ◽  
Vol 102 (1) ◽  
pp. 62-67 ◽  
Author(s):  
Roberto S. Toccafondi ◽  
Maria Luisa Brandi ◽  
Carlo M. Rotella ◽  
Roberto Zonefrati
Keyword(s):  
Cyclic Amp ◽  
Adrenergic Receptors ◽  
Human Thyroid ◽  
Adrenergic Nerve ◽  
Camp Accumulation ◽  
Follicular Cells ◽  
Functional Responses ◽  
Thyroid Cells ◽  
Thyroid Follicular Cells ◽  
Bovine Tsh

Abstract. Even though adrenergic nerve terminals between and around thyroid follicles and catecholamine stimulation of thyroid adenylate cyclase have been reported, there is no uniform concept on catecholamine interaction with thyrotrophin (TSH) receptors. Therefore, the effect of catecholamines on TSH-stimulated cyclic AMP (cAMP) accumulation in human follicular thyroid cells has been investigated, to thus eliminating the extrathyroidal actions of catecholamines. Epinephrine, norepinephrine and isoproterenol appeared to be rapid and potent stimulators of intracellular cAMP accumulation, the half maximum increase doses being 4 × 10−7m, 1 × 10−5m and 5 × 10−7m, respectively. While propranolol (1 × 10−5m) prevented the stimulatory effect of catecholamines and failed to inhibit the effect of bovine TSH, phentolamine (1 × 10−5m) enhanced the potency of norepinephrine and bovine TSH, leaving that of epinephrine unchanged. The effects of epinephrine (2 × 10−8m) and isoproterenol (2 × 10−8m) were additive to that of bovine TSH (0.5 mU/ml), but the effect of simultaneous stimulation with norepinephrine (5 × 10−7m) and bovine TSH (0.5 mU/ml) was lower than expected. Prenalterol, a selective β1-agonist, did not stimulate cAMP accumulation, while terbutaline, a selective β2-agonist, exerted a potent stimulation. Metoprolol, a selective β1-adrenergic blocker, did not affect the response of thyroid follicular cells to isoproterenol. These results demonstrate the existence of β-adrenergic receptors in human thyroid follicular cells, mainly of the type β2, apparently not correlated with TSH receptor. The existence of α-adrenergic receptors which counter-regulate TSH functional responses in human thyroid follicular cells is suggested.

Regulation of the astrocyte resting membrane potential by cyclic AMP and protein kinase A

Glia ◽  
2006 ◽  
Vol 54 (4) ◽  
pp. 316-328 ◽  
Author(s):  
Sally Bolton ◽  
Kirsty Greenwood ◽  
Nicola Hamilton ◽  
Arthur M. Butt
Keyword(s):  
Membrane Potential ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Kinase A ◽  
Resting Membrane Potential ◽  
Kinase A

scholarly journals Detection of SARS-COV-2 receptor ACE-2 mRNA in thyroid cells: a clue for COVID-19-related subacute thyroiditis

2020 ◽  
Author(s):  
M. Rotondi ◽  
F. Coperchini ◽  
G. Ricci ◽  
M. Denegri ◽  
L. Croce ◽  
...  
Keyword(s):  
Primary Cultures ◽  
Thyroid Tissue ◽  
Subacute Thyroiditis ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Type I ◽  
Rt Pcr ◽  
Follicular Cells ◽  
Thyroid Cells ◽  
Tissue Samples

Abstract Purpose SARS-COV-2 is a pathogenic agent belonging to the coronavirus family, responsible for the current global world pandemic. Angiotensin-converting enzyme 2 (ACE-2) is the receptor for cellular entry of SARS-CoV-2. ACE-2 is a type I transmembrane metallo-carboxypeptidase involved in the Renin-Angiotensin pathway. By analyzing two independent databases, ACE-2 was identified in several human tissues including the thyroid. Although some cases of COVID-19-related subacute thyroiditis were recently described, direct proof for the expression of the ACE-2 mRNA in thyroid cells is still lacking. Aim of the present study was to investigate by RT-PCR whether the mRNA encoding for ACE-2 is present in human thyroid cells. Methods RT-PCR was performed on in vitro ex vivo study on thyroid tissue samples (15 patients undergoing thyroidectomy for benign thyroid nodules) and primary thyroid cell cultures. Results The ACE-2 mRNA was detected in all surgical thyroid tissue samples (n = 15). Compared with two reporter genes (GAPDH: 0.052 ± 0.0026 Cycles−1; β-actin: 0.044 ± 0.0025 Cycles−1; ACE-2: 0.035 ± 0.0024 Cycles−1), the mean level of transcript expression for ACE-2 mRNA was abundant. The expression of ACE-2 mRNA in follicular cells was confirmed by analyzing primary cultures of thyroid cells, which expressed the ACE-2 mRNA at levels similar to tissues. Conclusions The results of the present study demonstrate that the mRNA encoding for the ACE-2 receptor is expressed in thyroid follicular cells, making them a potential target for SARS-COV-2 entry. Future clinical studies in patients with COVID-19 will be required for increase our understanding of the thyroid repercussions of SARS-CoV-2 infection.

Thyrotrophin regulation of apical and basal exocytosis of thyroglobulin by porcine thyroid monolayers

1990 ◽  
Vol 4 (3) ◽  
pp. 193-199 ◽  
Author(s):  
M. Chambard ◽  
D. Depetris ◽  
D. Gruffat ◽  
S. Gonzalvez ◽  
J. Mauchamp ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Culture System ◽  
Basal Medium ◽  
Pleiotropic Effect ◽  
Thyroid Cells ◽  
Chase Period ◽  
Thyroglobulin Gene ◽  
Bovine Tsh ◽  
Tsh Stimulation ◽  
Cells Cultured

ABSTRACT Exocytosis, the ultimate step in thyroglobulin secretion, has been studied in porcine thyroid cells cultured in monolayers on the permeable bottom of culture chambers. We have previously demonstrated, using this culture system, that apical secretion accounts for 85–95% of total secretion of newly synthesized thyroglobulin. When cells were cultured for several days with bovine TSH (25 μU/ml) in the basal medium, the rate of glycoprotein accumulation in the upper compartment was three times higher than that in the absence of TSH. In contrast, the rate of thyroglobulin released into the basal medium (5–15% of total secreted thyroglobulin) appeared unmodified by chronic TSH stimulation. To investigate the effect of acute TSH stimulation on thyroglobulin exocytosis in the apical and basal compartments, pulse-chase experiments were carried out with the same culture system. The release of radiolabelled thyroglobulin (1·5-h pulse) into the apical medium was increased threefold during the 2-h chase period under TSH stimulation. The radiolabelled thyroglobulin released into the basal medium was increased only 1·5- to 2-fold, and stimulation disappeared after 1 h. The effect of TSH was maximal when the chase medium contained 50 μU TSH/ml. However, cells cultured for several days in the presence of 25 μU TSH/ml before the pulse-chase experiment, appeared desensitized to acute TSH stimulation. Similar responses were observed when the chase medium contained 8-chloro-cyclic AMP or cholera toxin. This study provides another example of the pleiotropic effect of TSH, mediated by cyclic AMP, on the sequential steps of thyroglobulin gene expression in cultured thyroid cells in which the polar character of the epithelial cells is well preserved.

Differences in prostaglandin E2, prostaglandin F2α and prostacyclin contents and their response to thyrotrophin stimulation and in prostaglandin-stimulated cyclic AMP response in normal and Graves's thyroid slices

1983 ◽  
Vol 98 (3) ◽  
pp. 357-363 ◽  
Author(s):  
Nobuyuki Takasu ◽  
Kazunori Takahashi ◽  
Tatsuro Ishigami ◽  
Takashi Yamada ◽  
Seiya Sato
Keyword(s):  
Cyclic Amp ◽  
Prostaglandin E2 ◽  
Prostaglandin F2α ◽  
Human Thyroid ◽  
Prostaglandin E ◽  
Normal Thyroid ◽  
Cyclic Amp Synthesis

The human thyroid contained prostaglandin (PG) E2, PGF2α and 6-oxo-PGF1α, an end-metabolite of prostacyclin (PGI2), the 6-oxo-PGF1α content being the highest of these prostaglandins. Graves's thyroid contained a significantly higher amount of PGF2α and lower amounts of PGE2 and 6-oxo-PGF1α than the normal thyroid. Thyrotrophin acutely augmented the thyroid contents of PGE2, PGF2α and 6-oxo-PGF1α. The TSH-stimulated increases in PGE2 and 6-oxo-PGF1α were lower but the TSH-stimulated increase in PGF2α was significantly higher in Graves's thyroid than in the normal thyroid. Prostaglandin E2 and PGI2 stimulated human thyroid cyclic AMP synthesis, with the magnitudes of PGE2-and PGI2-stimulated increases in cyclic AMP being equal in normal and Graves's thyroid. Prostaglandin E2α did not stimulate cyclic AMP synthesis significantly. These results provide evidence that prostaglandins play important roles in thyroid physiology and the pathophysiology of Graves's disease.

scholarly journals Hormonally induced changes in the cytoskeleton of human thyroid cells in culture.

1982 ◽  
Vol 94 (1) ◽  
pp. 42-50 ◽  
Author(s):  
B Westermark ◽  
K R Portor
Keyword(s):  
Morphological Changes ◽  
Stress Fibers ◽  
Human Thyroid ◽  
Ground Substance ◽  
Intracellular Camp ◽  
Dibutyryl Camp ◽  
Follicular Cells ◽  
Thyroid Cells ◽  
High Voltage Electron Microscopy ◽  
Microfilament Bundles

Serially cultivated thyroid follicular cells are not active in hormone synthesis but retain a thyrotropin-responsive adenylate cyclase. The exposure of such cells to thyrotropin leads to an increase in the concentration of intracellular cAMP and a drastic change in morphology including a total cytoplasmic arborization. The present communication describes these changes at the cytoskeletal level using a cell line derived from a human functioning thyroid adenoma. Phase contrast microscopy showed that the cytoplasmic arborization was preceded by a total disappearance of stress fibers, visible within 20 min of exposure. Small marginal membrane ruffles could also be seen. These morphological changes could also be induced by the addition of dibutyryl cAMP. The action of both thyrotropin and dibutyryl cAMP was potentiated by theophylline. High voltage electron microscopy of whole mounted cells confirmed the loss of stress fibers (microfilament bundles). In addition, thyrotropin treatment led to an uneven redistribution of the cytoplasmic ground substance and to changes in the organization of the microtrabecular lattice. Stereo images demonstrated numerous minute surface ruffles. The thyrotropin-induced arborization was reversible even in the presence of thyrotropin. After 24 h of treatment, cells had flattened and then contained very straight and condensed microfilament bundles. The results thus demonstrate that thyrotropin induces a disintegration of microfilament bundles in human, partially dedifferentiated, follicular cells and that this effect to all appearances is caused by cAMP, the second messenger in thyrotropin action. The relation of this event in partially dedifferentiated cells to the effect of thyrotropin in the intact thyroid gland is unclear. The fact that several other cultured hormone-responsive cells round up or become arborized in conjunction with an increase in cAMP levels implies that cAMP may be a major factor in the disassembly of microfilament bundles in these cells.

A comparison of the bioactivity of human and bovine thyrotrophin preparations, as determined by intracellular cyclic AMP responses of cultured FRTL-5 cells and human thyroid cell monolayers

1984 ◽  
Vol 106 (4) ◽  
pp. 482-489 ◽  
Author(s):  
S. P. Bidey ◽  
K. Ryder ◽  
R. Gaines-Das ◽  
N.J. Marshall ◽  
R. P. Ekins
Keyword(s):  
Cyclic Amp ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Response Curves ◽  
Thyroid Cells ◽  
Response Parameter ◽  
Reference Preparation ◽  
Single Cell Type ◽  
Rat Thyroid ◽  
Bovine Tsh

Abstract. A clonal strain of thyrotrophin (TSH)-dependent rat thyroid cells (FRTL-5) has been used to evaluate the biological activity of reference preparations of both human and bovine TSH. Using the accumulation of intracellular cyclic AMP as a response parameter, the widely used bovine TSH preparation. Armour 'Thytropar', was calibrated against the First International Standard of Thyrotrophin (pituitary TSH), bovine, for immunoassay. Log dose – log response curves were parallel, and a relative potency of 2.4 IU/unit of 'Thytropar' was obtained. Subcultures of FRTL-5 cells were more responsive to both bovine and human TSH than were human thyroid follicular cells maintained as primary monolayer cultures. Dose-response curves for cyclic AMP accumulation were parallel for a single cell type differentially incubated with human TSH (the First International Reference Preparation) and bovine TSH (Armour 'Thytropar') preparations. The relative potencies (units: IU) of bovine-human TSH were of the order of 2.0 when tested on both FRTL-5 cultures and primary human thyroid monolayers. This suggests that in the spectrum of structural differences between TSH receptors of different species, the discriminatory powers of the human and FRTL-5 cell TSH receptor are similar. Thus FRTL-5 cells form the basis of a bioassay system of considerable value in the study of human thyroid stimulators, as we demonstrate in an evaluation of two recent preparations of human TSH.

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