Cyclic AMP release from normal human thyroid slices in response to thyrotrophin

1980 ◽  
Vol 95 (3) ◽  
pp. 335-340 ◽  
Author(s):  
Stephen P. Bidey ◽  
Nicholas J. Marshall ◽  
Roger P. Ekins
Keyword(s):  
Cyclic Amp ◽  
Incubation Time ◽  
Thyroid Tissue ◽  
Human Thyroid ◽  
Dose Dependency ◽  
Incubation Periods ◽  
In Vitro Exposure ◽  
Normal Human ◽  
Stimulation Of

Abstract. Slice preparations of normal human thyroid tissue were incubated in vitro with TSH. The cyclic AMP contents of slices were determined at intervals up to 120 min, and cyclic AMP in the incubation medium was also estimated for each incubation period. Slice cyclic AMP levels were related both to incubation time and TSH dose. In response to 10 mU TSH/ml, slice cyclic AMP levels were maximal within 60 min, and were not significantly changed at 120 min. Cyclic AMP was detectable in the medium within 10 min of slice exposure to TSH, and increased throughout the initial 60 min of incubation. Cyclic AMP release during this period was dependent on both TSH dose and incubation time. Between 60–120 min, however, cyclic AMP release partially lost its TSH dose-dependency, and 0.5–5.0 mU TSH/ml were equipotent with respect to the final medium cyclic AMP level attained. Slices incubated without TSH released only small amounts of cyclic AMP, and maximal levels were attained within 20 min. In contrast to the adenylate cyclase response of thyroid membrane preparations, which was stimulated by NaF, suggesting that cyclic AMP release was not a result of the stimulation of damaged cells. These findings demonstrate the importance of cyclic AMP release from human thyroid slices, following in vitro exposure to TSH, and suggest that, after incubation periods such as are used for the functional biodetection of thyroid stimulators, the magnitude of cyclic AMP release may be of quantitative significance.

Characterisation of the cyclic AMP response to thyrotrophin in monolayer cultures of normal human thyroid cells

1981 ◽  
Vol 98 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Stephen P. Bidey ◽  
Nicholas J. Marshall ◽  
Roger P. Ekins
Keyword(s):  
Cyclic Amp ◽  
Dose Range ◽  
Thyroid Tissue ◽  
Human Thyroid ◽  
Thyroid Cells ◽  
Monolayer Cultures ◽  
Normal Human ◽  
Stimulation Of ◽  
In Cells

Abstract. The cyclic AMP response to thyrotrophin (TSH) has been investigated in cells prepared from human thyroid tissue obtained during surgery for sub-total laryngectomy, and maintained under in vitro conditions as primary monolayer cultures. When cells were incubated with 1.0 mU TSH/ml, a maximal level of intracellular cyclic AMP was reached after 20 min of incubation in the presence of 0.5 mm 3-isobutyl-1-methyl xanthine (MIX). This level of cyclic AMP was sustained for at least 2 h. Half-maximal stimulation of cyclic AMP was produced by TSH doses of between 1 and 5 mU/ml. In a study of a series of eight groups of monolayer cultures, each derived from a single, different thyroid gland, the mean stimulation of cyclic AMP given by 50 mU TSH/ml was 37.8-fold greater than in non-stimulated cell monolayers. Significant stimulation to 50 μU TSH/ml was observed in some monolayers and the precision of measurement of TSH was better than 15% over the TSH dose range 0.2–1.0 mU/ml. The magnitude of the cyclic AMP response to TSH was unaffected by the presence in the incubation medium of 20% (v/v) normal human serum. A cyclic AMP response to TSH was still demonstrable in cells that had been maintained for a period of 22 days in monolayer culture, although the response was reduced in comparison with that given by 4–5 day old cultures.

IN-VITRO STUDIES OF NORMAL HUMAN THYROID CELLS: RESPONSES TO THYROTROPHIN AND DIBUTYRYL CYCLIC AMP

1977 ◽  
Vol 72 (1) ◽  
pp. 87-96 ◽  
Author(s):  
S. P. BIDEY ◽  
P. MARSDEN ◽  
J. ANDERSON ◽  
C. G. McKERRON ◽  
H. BERRY
Keyword(s):  
Cyclic Amp ◽  
Thyroid Tissue ◽  
Three Dimensional ◽  
Human Thyroid ◽  
Dibutyryl Cyclic Amp ◽  
Iodide Uptake ◽  
Thyroid Cells ◽  
Normal Human

SUMMARY Follicular cells isolated from normal human thyroid tissue have been cultured for up to 140 h with bovine thyrotrophin (TSH) or dibutyryl cyclic AMP (DBcAMP). Both compounds induced marked reorganization of the cells into three-dimensional follicular structures, whilst non-supplemented cells assumed a monolayer form. Cultures treated initially with TSH or DBcAMP showed a greater iodide uptake capacity, in comparison with unsupplemented cultures, in which iodide uptake was markedly diminished after 24 h. The release of tri-iodothyronine (T3) and thyroxine (T4) into the medium was determined by radioimmunoassay. Both TSH- and DBcAMP-treated cells showed a significant increase in iodothyronine output compared with unsupplemented control cells. In contrast to the 'classical' TSH-induced depression of the T4:T3 ratio in vivo, an increase in the ratio was observed for both TSH- and DBcAMP-supplemented cells in vitro. The ratio was also significantly greater after TSH than after DBcAMP, and possible implications of this finding are discussed.

INHIBITION BY NORMAL IMMUNOGLOBULINS OF THYROTROPHIN-STIMULATED PRODUCTION OF CYCLIC AMP IN SLICES OF NORMAL HUMAN THYROID

1980 ◽  
Vol 87 (2) ◽  
pp. 271-277 ◽  
Author(s):  
S. P. BIDEY ◽  
N. J. MARSHALL ◽  
R. P. EKINS
Keyword(s):  
Cyclic Amp ◽  
Immunoglobulin G ◽  
Thyroid Tissue ◽  
Human Thyroid ◽  
Human Thyroid Tissue ◽  
Thyroid Stimulating Antibodies ◽  
Cyclic Amp Accumulation ◽  
Normal Human ◽  
Stimulation Of

Slice preparations of normal human thyroid tissue have been used to investigate the effect of normal immunoglobulin G (IgG) on thyrotrophin (TSH)-induced accumulation of cyclic AMP. Incubation of slices in the presence of both TSH and normal IgG for 20 min reduced the stimulation of cyclic AMP accumulation elicited by TSH alone by approximately 30%. However, preincubation of slices with IgG for 100 min before addition of TSH virtually abolished the response to TSH. The latter effect of normal IgG was reversible, and removal of IgG before exposure to TSH allowed an unimpaired cyclic AMP response to TSH. The implications of these observations with respect to the application of this system to the functional bio-detection of thyroid-stimulating antibodies in IgG fractions from thyrotoxic sera are discussed.

Evaluation of the rat thyroid cell strain FRTL-5 as an in-vitro bioassay system for thyrotrophin

1984 ◽  
Vol 101 (3) ◽  
pp. 269-NP ◽  
Author(s):  
S. P. Bidey ◽  
L. Chiovato ◽  
A. Day ◽  
M. Turmaine ◽  
R. P. Gould ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Tissue Slices ◽  
Iodide Uptake ◽  
Thyroid Cells ◽  
Rat Thyroid ◽  
Bovine Tsh ◽  
Stimulation Of

ABSTRACT The cyclic AMP response to bovine TSH was characterized in a strain of rat thyroid follicular cells (FRTL-5) maintained in continuous culture. Significant stimulation of intracellular cyclic AMP was attained at a TSH dose of 5 μu./ml. Cyclic AMP accumulation continued to increase, at higher TSH doses, with no evidence for attainment of a maximum level at the highest dose tested (5 mu./ml). The precision of TSH measurement was better than 10% over the range 50–5000 μu./ml, comparing favourably with that observed with analogous assays based on human cells, tissue slices or membrane preparations. Using sequential subcultures of FRTL-5 cells, the between-assay variation in response to a single dose of a standard preparation of bovine TSH (53/11; 370 μu./ml) was of the order of 20% which compared favourably with the between-assay variation observed with different cultures of human thyroid cells. Prolongation of the incubation of FRTL-5 cells with TSH to 3 h revealed a progressive increase in the extracellular accumulation of cyclic AMP. Addition of TSH to resting FRTL-5 cells resulted in a stimulation of inorganic iodide uptake with pronounced bell-shaped dose–response characteristics. Thus a maximum uptake was observed at a TSH dose of 100 μu./ml with a significant reduction at higher doses. Acute stimulation of cells with TSH (100 μu./ml) resulted in a rapid and marked alteration in cell morphology, with evidence of cellular retraction and surface ruffling. J. Endocr. (1984) 101, 269–276

scholarly journals Interactions between adenylate cyclase and the yeast GTPase-activating protein IRA1.

1991 ◽  
Vol 11 (9) ◽  
pp. 4591-4598 ◽  
Author(s):  
M R Mitts ◽  
J Bradshaw-Rouse ◽  
W Heideman
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Adenylate Cyclase System ◽  
Gtpase Activating Protein ◽  
Yeast Saccharomyces Cerevisiae ◽  
Strong Candidate ◽  
Sepharose 4B ◽  
Stimulation Of ◽  
Cyclic Amp Synthesis

The adenylate cyclase system of the yeast Saccharomyces cerevisiae contains many proteins, including the CYR1 polypeptide, which is responsible for catalyzing the formation of cyclic AMP from ATP, RAS1 and RAS2 polypeptides, which mediate stimulation of cyclic AMP synthesis by guanine nucleotides, and the yeast GTPase-activating protein analog IRA1. We have previously reported that adenylate cyclase is only peripherally bound to the yeast membrane. We have concluded that IRA1 is a strong candidate for a protein involved in anchoring adenylate cyclase to the membrane. We base this conclusion on the following criteria: (i) a disruption of the IRA1 gene produced a mutant with very low membrane-associated levels of adenylate cyclase activity, (ii) membranes made from these mutants were incapable of binding adenylate cyclase in vitro, (iii) IRA1 antibodies inhibit binding of adenylate cyclase to the membrane, and (iv) IRA1 and adenylate cyclase comigrate on Sepharose 4B.

COMPARISON OF THE STIMULATORY EFFECTS OF OVINE, PORCINE AND HUMAN FOLLICLE-STIMULATING HORMONE AND OF OVINE AND HUMAN LUTEINIZING HORMONE ON THE ACCUMULATION OF CYCLIC AMP BY PORCINE GRANULOSA CELLS

1979 ◽  
Vol 80 (1) ◽  
pp. 9-20 ◽  
Author(s):  
ADA M. LINDSEY ◽  
CORNELIA P. CHANNING
Keyword(s):  
Cyclic Amp ◽  
Granulosa Cells ◽  
Incubation Medium ◽  
Follicle Stimulating Hormone ◽  
Similar Response ◽  
Intracellular Accumulation ◽  
Porcine Granulosa Cells ◽  
Tenfold Increase ◽  
Incubation Periods

The effects of ovine, porcine and human FSH, and ovine and human LH on the accumulation of cyclic AMP by porcine granulosa cells obtained from follicles at various stages of maturation were investigated. During incubation periods of 15 min, 10 μg ovine FSH pretreated with antiserum to LH or 10 μg human FSH resulted in an 11- to 18-fold, five-to ninefold, and less than a twofold increase in intracellular accumulation of cyclic AMP by granulosa cells from small (1–2 mm), medium (3–5 mm) and large (6–12 mm) follicles respectively. Similar patterns of response occurred with addition of porcine FSH. After incubation for 30 and 60 min with ovine, porcine or human FSH, significant accumulation of cyclic AMP in the incubation medium occurred with cells obtained from small and medium-sized follicles. After 60 min of incubation with FSH the accumulation of cyclic AMP in the incubation medium exceeded the intracellular cyclic AMP levels in granulosa cells from small and medium-sized follicles. During incubation periods of 15 min, 1·0 μg ovine LH resulted in less than a twofold, a fourfold and greater than a tenfold increase in intracellular accumulation of cyclic AMP by granulosa cells from small, medium and large follicles respectively. Addition of human LH brought about a similar response. Incubation periods of 30 and 60 min with 1·0 μg ovine or human LH resulted in significant accumulation of cyclic AMP in the incubation medium by granulosa cells from large follicles; cyclic AMP content in the incubation medium was greater after 60 min compared with 30 min of incubation. It was concluded that ovine FSH pretreated with an antiserum to LH had similar effects on cyclic AMP levels as did purified human and porcine FSH, and that the stimulatory effects of the less pure ovine FSH were probably not due to an impurity in the FSH preparation. Porcine granulosa cells obtained from small follicles should be suitable as an in-vitro FSH bioassay while granulosa cells obtained from large follicles should be suitable as an in-vitro LH bioassay.

Possible role of cyclic GMP in stimulus-secretion coupling by salt gland of the duck

1979 ◽  
Vol 237 (5) ◽  
pp. C200-C204 ◽  
Author(s):  
D. J. Stewart ◽  
J. Sax ◽  
R. Funk ◽  
A. K. Sen
Keyword(s):  
Cyclic Amp ◽  
Guanylate Cyclase ◽  
Cyclic Gmp ◽  
Salt Gland ◽  
Domestic Ducks ◽  
Stimulus Secretion Coupling ◽  
Stimulation Of

Stimulation of salt galnd secretion in domestic ducks in vivo increased the cyclic GMP concentration of the tissue, but had no effect on cyclic AMP levels. Methacholine, which is known to stimulate sodium transport by the glands both in vivo and in vitro, stimulated ouabain-sensitive respiration in salt gland slices. Cyclic GMP stimulated ouabain-sensitive respiration to the same extent as methacholine. Guanylate cyclase stimulators, hydroxylamine and sodium azide, also stimulated ouabain-sensitive respiration. The stimulation of ouabain-sensitive respiration by methacholine was blocked either by atropine or by removal of calcium from the incubation medium. The stimulation of ouabain-sensitive respiration by cyclic GMP still occurred in the absence of calcium. The above observations seem to indicate that cyclic GMP acts as a tertiary link in the process of stimulus-secretion coupling in the tissue.

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