The thyroidal response to chronic goitrogenic stimulation and the persistence of effects of early goitrogenic stimulation

1976 ◽  
Vol 54 (4) ◽  
pp. 583-589 ◽  
Author(s):  
Peter Leung ◽  
B. E. March
Keyword(s):  
Thyroid Gland ◽  
Coupling Efficiency ◽  
Iodine Content ◽  
Rapeseed Meal ◽  
Epithelial Tissue ◽  
Radioiodine Uptake ◽  
Growing Period ◽  
Follicle Diameter ◽  
Thyroid Glands ◽  
Production Characteristics

The effects of overstimulation of the thyroid gland induced by the feeding of rapeseed meal or thiouracil during the growing period persisted for as long as 75 weeks after withdrawal of the source of goitrogen from the diet. Thyroid weight, thyroid iodine content and radioiodine uptake were all increased in birds which had received goitrogen during the growing period. Follicle diameter was greater and the height of epithelial cells was lower than in control birds. The thyroid changes in these birds were deduced to be compensatory because production characteristics were normal and distribution of a dose of radioiodine into thyronines (T3 + T4) was similar in the birds which had received goitrogen during the growing period and in the control birds. Birds which were being fed rapeseed meal at the time the thyroid glands were examined showed effects which varied in magnitude according to the length of time over which rapeseed meal had been fed. Thyroid weight, follicle diameter, amount of epithelial tissue present and the total amount of iodine in the thyroid glands increased, whereas coupling efficiency (radioiodine-labelled T3 + T4)/(monoiodotyrosine/diiodotyrosine) declined with time.

scholarly journals Effect of iodine or iopanoic acid on thyroid Ca2+/NADPH-dependent H2O2-generating activity and thyroperoxidase in toxic diffuse goiters

2002 ◽  
pp. 293-298 ◽  
Author(s):  
LC Cardoso ◽  
DC Martins ◽  
DV Campos ◽  
LM Santos ◽  
VM Correa da Costa ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Thyroid Hormones ◽  
Iodine Content ◽  
Nadph Oxidase Activity ◽  
Iopanoic Acid ◽  
Thyroid Glands ◽  
Drug Regimens ◽  
High Doses ◽  
Serum Thyroid Hormones ◽  
Serum Tsh

OBJECTIVE: The aim of the present study was to compare the effects of iopanoic acid (IOP) or a saturated solution of potassium iodide (SSKI) administration to patients with toxic diffuse goiters (TDG). DESIGN: Patients with TDG are treated with thionamides and high doses of iodine preoperatively. In this study, two types of preoperative drug regimens were used: propylthiouracil or methimazole plus SSKI for 10-15 days (n=8) or IOP for 7 days (n=6). METHODS: Serum thyroid hormones (total and free thyroxine (T(4)), total tri-iodothyronine (T(3)) and reverse T(3) (rT(3)), were evaluated after 7 days of either SSKI or IOP treatment, and after 10-15 days of SSKI administration. During thyroidectomy, samples of thyroid gland were obtained to evaluate thyroperoxidase and thyroid H(2)O(2)-generating activities. RESULTS: Serum total T(3) was significantly decreased after 7 days of either treatment, and serum rT(3) was significantly increased in IOP-treated patients. Serum total and free T(4) were unaffected by 7 days of IOP treatment, but decreased after 7 days of SSKI treatment, although significantly diminished levels were only reached after a further 3-8 days of SSKI administration. During both drug regimens, serum TSH remained low (SSKI: 0.159+/-0.122; IOP: 0.400+/-0.109 microU/ml). Thyroperoxidase activity was significantly lower in thyroid samples from patients treated with SSKI for 10-15 days than in the thyroid glands from IOP-treated patients. However, thyroid H(2)O(2) generation was inhibited in samples from patients treated with either IOP or SSKI. CONCLUSIONS: We show herein that IOP treatment can be effective in the management of hyperthyroidism and that this drug inhibits thyroid NADPH oxidase activity, just as previously described for SSKI, probably due to its iodine content.

Histological Study of Human Thyroid Gland Relative Proportion of Parenchyma and Stroma in Thyroid Glands of Bangladeshi People

2013 ◽  
Vol 1 (2) ◽  
pp. 17-20
Author(s):  
Md Enayet Ullah ◽  
Hasna Hena ◽  
Rubina Qasim
Keyword(s):  
Thyroid Gland ◽  
Histological Study ◽  
Relative Proportion ◽  
Age Groups ◽  
Human Thyroid ◽  
Structural Units ◽  
Thyroid Glands ◽  
Group A ◽  
Group B ◽  
Connective Tissue Sheath

Deep cervical fascia forms a connective tissue sheath around the thyroid gland. Delicate trabeculae and septa penetrate the gland indistinctly dividing the gland into lobes and lobules which in turn composed of follicles.1,2,3 These follicles are structural units of thyroid gland which varies greatly in size and shape.4 The number of follicles varies in different age groups. The study was carried out to see the percentage of area occupied by follicles in the stained section of thyroid glands in different age groups. The collected samples were grouped as A (3.5 – 20yrs), B (21- 40yrs) & C (41 – 78yrs). Percentage of area occupied by follicles was (58.55±10.72) in group A, (63.79±12.35) in group B + (63.39±8.29) in group C.DOI: http://dx.doi.org/10.3329/updcj.v1i2.13981 Update Dent. Coll. j. 2011: 1(2): 17-20

INHIBITION OF THYROGLOBULIN BIOSYNTHESIS AND DEGRADATION BY EXCESS IODIDE. SYNERGISM WITH LITHIUM

1976 ◽  
Vol 81 (2) ◽  
pp. 495-506 ◽  
Author(s):  
A. Radvila ◽  
R. Roost ◽  
H. Bürgi ◽  
H. Kohler ◽  
H. Studer
Keyword(s):  
Protein Synthesis ◽  
Thyroid Gland ◽  
Inhibitory Action ◽  
Inhibit Protein Synthesis ◽  
Thyrotrophic Hormone ◽  
Thyroid Glands ◽  
Pre Treatment ◽  
Excess Iodide ◽  
Kidney Liver

ABSTRACT Lithium and excess iodide inhibit the release of thyroid hormone from preformed stores. We thus tested the hypothesis that this was due to an inhibition of thyroglobulin breakdown. Rats were pre-treated with propylthiouracil (PTU) for 3 weeks in order to deplete their thyroids of thyroglobulin. While the PTU was continued, lithium chloride (0.25 mEq./100 g weight) or potassium iodide (3 mg per rat) were injected every 12 h for 3 days. Thereafter the thyroglobulin content in thyroid gland homogenates was measured. PTU pre-treatment lowered the thyroglobulin content from 4.21 to 0.22 mg/100 mg gland. Lithium caused a marked re-accumulation of thyroglobulin to 0.60 mg/100 mg within 3 days. While iodide alone had only a borderline effect, it markedly potentiated the action of lithium and a combination of the two drugs increased the thyroglobulin content to 1.04 mg/100 mg. Thyroxine was injected into similarly pre-treated animals to suppress secretion of thyrotrophic hormone. This markedly inhibited the proteolysis of thyroglobulin and 1.3 mg/100 mg gland accumulated after 3 days. Excess iodide, given in addition to thyroxine, decreased the amount of thyroglobulin accumulated to 0.75 mg/100 mg gland. To study whether this could be explained by an inhibitory action of iodide on thyroglobulin biosynthesis, thyroid glands from animals treated with excess iodide were incubated in vitro in the presence of 0.2 mm iodide for 3 h. Iodide decreased the incorporation of radioactive leucine into total thyroidal protein and into thyroglobulin by 25 and 35 % respectively. Iodide did not inhibit protein synthesis in the kidney, liver or muscle tissue. Thus, large doses of iodide selectively inhibit thyroglobulin biosynthesis.

Infants Diagnosed with Athyreosis on Scintigraphy May Have a Gland Present on Ultrasound and Have Transient Congenital Hypothyroidism

2021 ◽  
pp. 1-8
Author(s):  
Niamh McGrath ◽  
Colin Patrick Hawkes ◽  
Stephanie Ryan ◽  
Philip Mayne ◽  
Nuala Murphy
Keyword(s):  
Thyroid Gland ◽  
Congenital Hypothyroidism ◽  
Thyroid Tissue ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Ultrasound ◽  
Free T4 ◽  
Median Serum ◽  
Thyroid Glands ◽  
Rule Out

Scintigraphy using technetium-99m (<sup>99m</sup>Tc) is the gold standard for imaging the thyroid gland in infants with congenital hypothyroidism (CHT) and is the most reliable method of diagnosing an ectopic thyroid gland. One of the limitations of scintigraphy is the possibility that no uptake is detected despite the presence of thyroid tissue, leading to the spurious diagnosis of athyreosis. Thyroid ultrasound is a useful adjunct to detect thyroid tissue in the absence of <sup>99m</sup>Tc uptake. <b><i>Aims:</i></b> We aimed to describe the incidence of sonographically detectable in situ thyroid glands in infants scintigraphically diagnosed with athyreosis using <sup>99m</sup>Tc and to describe the clinical characteristics and natural history in these infants. <b><i>Methods:</i></b> The newborn screening records of all infants diagnosed with CHT between 2007 and 2016 were reviewed. Those diagnosed with CHT and athyreosis confirmed on scintigraphy were invited to attend a thyroid ultrasound. <b><i>Results:</i></b> Of the 488 infants diagnosed with CHT during the study period, 18/73 (24.6%) infants with absent uptake on scintigraphy had thyroid tissue visualised on ultrasound (3 hypoplastic thyroid glands and 15 eutopic glands). The median serum thyroid-stimulating hormone (TSH) concentration at diagnosis was significantly lower than that in infants with confirmed athyreosis (no gland on ultrasound and no uptake on scintigraphy) (74 vs. 270 mU/L), and median free T4 concentration at diagnosis was higher (11.9 vs. 3.9 pmol/L). Six of 10 (60%) infants with no uptake on scintigraphy but a eutopic gland on ultrasound had transient CHT. <b><i>Conclusion:</i></b> Absent uptake on scintigraphy in infants with CHT does not rule out a eutopic gland, especially in infants with less elevated TSH concentrations. Clinically, adding thyroid ultrasound to the diagnostic evaluation of infants who have athyreosis on scintigraphy may avoid committing some infants with presumed athyreosis to lifelong levothyroxine treatment.

scholarly journals ENGLISH VERSION: AGE FEATURES OF RADIOACTIVE IODINE (131I) ABSORPTION BY RAT THYROID GLANDS IN CORRECTION OF THE DIETARY IODINE DEFICIENCY WITH ORGANIC IODINE

2021 ◽  
Vol 25 (1-2) ◽  
pp. 31-35
Author(s):  
O.I. Ryabukha
Keyword(s):  
Thyroid Gland ◽  
Iodine Deficiency ◽  
Radioactive Iodine ◽  
Male Rats ◽  
Organic Iodine ◽  
Study Results ◽  
Thyroid Glands ◽  
Immature Rats ◽  
Old Rats ◽  
Rat Thyroid

The structure of endocrine morbidity is characterized by a significant spread of thyroid pathology. The insufficient efficacy of inorganic iodine drugs poses the problem of search for new means for iodine deficiency treatment and prevention. Given the progressive aging of the population in economically developed countries, the purpose of the study was to clarify the effect of organic iodine on the features of absorption and elimination of radioactive iodine from the thyroid glands of variously aged rats in the conditions of iodine deficiency in the diet. The study was performed on nonlinear white male rats in two series of studies that were kept on iodine-deficient isocaloric starch-casein diet for 60 days: the first series included two groups of old rats weighing 0.400-0.450 kg, the second series – two groups of sexually immature rats weighing 0.060-0.090 kg. There were 5 rats in each group. In animals of the experimental groups in each series, 10% of casein in the diet was replaced with organic iodine, which came with iodine-protein preparation from the red Black Sea algae Phyllophora nervosa. The functional state of the thyroid gland was studied using the Sodium Iodide Na 131 I Injection drug. The dosimetry was performed using the STS-6 Geiger-Muller Detector. Radioindication of the thyroid gland was carried out after subcutaneous administration of 0.1 ml of 131I solution at the following time intervals: 0.5, 1, 2, 4, 6, 8, 10, 12, 24, 48, 72, and 96 hours after administration of 131I. The study results were presented as a percentage of the radioiodine dose administered, adjusted for natural radioactivity background and the radioactive decay of the drug. It was found that in the iodine deficiency conditions, the thyroid glands of old rats have higher rates of radioiodine absorption and a lower rate of its excretion than the glands of immature rats, which indicates their lower iodine reserve and greater liability to iodine deficiency pathology. Intake of organic iodine regardless of the rats’ age is accompanied by a decrease in radioiodine accumulation and acceleration of its excretion from the thyroid gland, which indicates a decrease in functional stress, but the glands of older rats absorb more iodine and excrete it more slowly, indicating less effective correction of iodine deficiency with age. Reduced functional activity of the thyroid glands in old rats can be used as a sensitive changes marker for the in-depth study of thyrotropic and thyroid disrupting effects.

scholarly journals The effect of iodine and strumigens long-term foodborne intake on histometrical parameters of thyroid gland in gimmers

2013 ◽  
Vol 61 (5) ◽  
pp. 1365-1369
Author(s):  
Zdeněk Peksa ◽  
Jan Trávníček ◽  
Roman Konečný ◽  
František Jelínek ◽  
Hana Dušová ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Dry Matter ◽  
Experimental Period ◽  
Rapeseed Meal ◽  
Iodine Intake ◽  
Control Group ◽  
High Iodine ◽  
Average Size ◽  
Experimental Group

In 2010 and 2011 two experiments on gimmers of Šumava mountain sheep were performed. The first experiment was carried out on 12 animals (experimental period was 11 months); control group was fed with 3 mg I*kg−1 in dry matter per day and experimental group was fed with 5 mg I*kg−1 in dry matter per day. The second experiment lasted 10 months and it was carried out on 12 animals. Feed ration for control group contained 10 mg I*kg DM−1. Feed ration for experimental group contained 10 mg I*kg DM−1 too; moreover it included rapeseed meal and 1 g of sodium nitrate. The aim of the first experiment was focused on impact of high iodine intake on structure of thyroid gland. The aim of the second experiment was to discover effect of strumigens during high iodine intake on structure of thyroid gland. The animals were slaughtered after the experiment and there was executed the dissection of thyroid gland. The samples of thyroid gland were processed during classic paraffin method and dyed with haematoxylin and eosin. For finding of histometrical parameters was used program Leica IM 500 Version 4.0. The length, the width and the area of follicles were measured. The follicles were divided into three groups after this procedure (by the length); in each group were measured 20 thyreocytes. In group with intake 5 mg I*kg DM−1 (experiment from year 2010): higher weight of thyroid (p < 0.01), significant higher (p < 0.05) proportional representation of large and medium follicles, significantly (p < 0.05) higher average size of follicles, demonstrably lower (p < 0.05) height of epithelium were found. There were not found any differences in monitored parameters between the groups from experiment which was carried out during the year 2011. After comparing results from the both experiments significantly higher percentage representation of large follicles a significantly lower representation of small follicles, distinctly higher average size and higher height of epithelium in all size categories, in groups with iodine intake 10 mg I*kg DM−1was found (from second experiment – year 2011).

scholarly journals Low Dose Ketoconazole Therapy and Thyroid Functions in Rats

2002 ◽  
Vol 45 (4) ◽  
pp. 177-179 ◽  
Author(s):  
Hüseyin Çaksen ◽  
Ahmet Tutuş ◽  
Selim Kurtoğlu ◽  
Figen Öztürk ◽  
Yüksel Okumuş ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Epithelial Cells ◽  
Low Dose ◽  
Thyroid Stimulating Hormone ◽  
Control Group ◽  
Histopathological Analysis ◽  
Study Group ◽  
Thyroid Function Tests ◽  
End Of Treatment ◽  
Thyroid Glands

To determine whether low dose ketoconazole (KTZ) has antithyroid action, we studied thyroid function tests in the 13 rats treated with KTZ (20 mg/kg twice daily) for thirty days. Serum triiodothyronine and thyroxine levels were decreased (P <0.05) and serum thyroid-stimulating hormone levels were mildly increased (P >0.05) at the end of treatment. Histopathological analysis of the thyroid glands demonstrated an increase in cylindrical cells in study group, but the epithelial cells were mainly cubical in control group. These findings showed that low dose KTZ had antithyroid effect in rats. The responsible mechanisms may be direct effect of the drug on thyroid gland.

scholarly journals Iodine and iodothyronine content in human neonate thyroid gland

2002 ◽  
Vol 54 (3-4) ◽  
pp. 69-74 ◽  
Author(s):  
Svetlana Savin-Zegarac ◽  
Dubravka Cvejic ◽  
Olgica Nedic ◽  
R. Radosavljevic ◽  
Ivana Petrovic
Keyword(s):  
Thyroid Gland ◽  
Gestational Age ◽  
Thyroid Tissue ◽  
Iodine Content ◽  
Postnatal Life ◽  
Total Iodine ◽  
Mean Values ◽  
Human Neonate ◽  
The Mean ◽  
Human Neonates

A few years after the iodine content of salt in Serbia was increased from 7 to 15 mg/kg NaCI, iodine, thyroxine (T4) and triiodothyronine (T3) concentrations were measured in thyroid tissue obtained at autopsy from 21 human neonates who died within 30 days after birth. The thyroidal iodine as well as T4 and T3 content per gland in?creased progressively with gestational age of human neonates (r = 0.73, 0.70 and 0.67 respectively, p < 0.001). In seven newborns (gestational age 36 to 41 weeks) the mean values for total iodine, T4 and T3 per gland were 109.1 ?g, 52.2 ?g and 4.4 ?g respectively. The results of iodine and iodothyroninc content found in neonatal thyroid gland, particularly at the end of gestation and a few days of postnatal life, indicates that the iodine supply was satisfactory.

scholarly journals MORPHOLOGY OF THYROID GLAND- A COMPARATIVE STUDY BETWEEN MALE AND FEMALE THYROID GLANDS

2019 ◽  
Vol 7 (4.3) ◽  
pp. 7193-7198
Author(s):  
S Monica Diana ◽  
◽  
S Supa Devi ◽  
Rieyaz H A ◽  
◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Comparative Study ◽  
Male And Female ◽  
Thyroid Glands
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