THYROID FUNCTION IN PROTEIN-DEPLETED RATS

1970 ◽  
Vol 46 (1) ◽  
pp. 93-99 ◽  
Author(s):  
W. H. FLORSHEIM ◽  
BIRUTA Z. SUHR ◽  
R. T. MIRISE ◽  
A. D. WILLIAMS
Keyword(s):  
Serum Albumin ◽  
Thyroid Function ◽  
Acid Content ◽  
Iodine Content ◽  
Protein Depletion

SUMMARY Renal iodide clearance in rats was reduced rapidly when the animals were fed a protein-depletion diet. If the iodine content of the protein-depletion diet is high, this results in an increase in the serum iodide levels to concentrations in excess of 150 μg./100 ml. Protein-bound iodine was elevated due to the accumulation of iodinated serum albumin. Thyroid hormonal iodoamino acid content was transiently depressed, presumably by the mechanism described by Wolff & Chaikoff (1948). Thyroxine metabolism was not affected except for a change in the partition of thyroxine between liver and serum. There was no evidence for pituitary involvement in the effects of protein depletion on thyroid function.

Thyroid function of subjects with goitre and cretinism in an endemic goitre area of rural China after use of iodized salt

1988 ◽  
Vol 118 (3) ◽  
pp. 444-448 ◽  
Author(s):  
Xuan-Ping Pang ◽  
An Ouyang ◽  
Tian-Sue Su ◽  
Jerome M. Hershman
Keyword(s):  
Thyroid Function ◽  
Rural China ◽  
Public Health Problem ◽  
Iodine Content ◽  
Iodine Concentration ◽  
Epidemiological Survey ◽  
Iodized Salt ◽  
Endemic Goitre ◽  
Serum Thyroglobulin ◽  
Serum Free

Abstract. Endemic goitre and cretinism are still a public health problem in China. An epidemiological survey showed that about 5% of the inhabitants in Daxin village, Henan province, had goitre or cretinism after an iodized salt prevention programme had been carried out for two decades. The main food for the inhabitants of this area has an iodine content <30 nmol/kg and the water for cooking and drinking has an iodine concentration between 7–12 nmol/l. We studied thyroid function in subjects of this village. There were 42 with grade 0 goitre (males 29, females 13), 42 grade I (males 23, females 19), 27 grade II (males 9, females 18), 31 grade III (males 14, females 17) and 34 cretinism patients (males 30, females 4) diagnosed and classified according to WHO criteria. Serum T4, free T4, T3, free T3, T3 uptake, TSH and thyroglobulin were measured in these subjects. The patients with goitre or cretinism had significantly decreased serum free T4 and increased serum T3 and free T3 levels compared with those of controls. Thyroid size was positively correlated with age and serum thyroglobulin concentrations. Serum thyroglobulin was significantly increased even in the grade 0 goitre subjects. The percentages of subjects with serum free T4 < 12 nmol/l, T3 >2.5 nmol/l, free T3 >5.2 pmol/l, TSH >3.5 mU/l, T3/T4 ratio >0.03 and free T3/free T4 ratio >0.36 were significantly higher among goitre and cretinism patients than among controls. The data suggest that there is partial compensation for a marginal deficiency of iodine in the inhabitants of this village.

scholarly journals Moderate Iodine Deficiency Is Common in Pregnancy but Does Not Alter Maternal and Neonatal Thyroid Function Tests

2020 ◽  
Vol 11 ◽  
Author(s):  
Tal Schiller ◽  
Arnon Agmon ◽  
Viviana Ostrovsky ◽  
Gabi Shefer ◽  
Hilla Knobler ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Content ◽  
First Trimester ◽  
Thyroid Function Tests ◽  
Neonatal Thyroid Function ◽  
Iodine Deficiency In Pregnancy ◽  
In Pregnancy

IntroductionAn Israeli national survey found that 85% of pregnant women had urinary iodine content (UIC) levels below the adequacy range (&lt;150 µg/L). Widespread desalinated water usage and no national fortification plan are possible causes. Studies assessing relationships between iodine status and maternal and neonatal thyroid function provided varying results. Our aims were to determine whether iodine deficiency was associated with altered maternal or neonatal thyroid function and the factors leading to iodine deficiency.MethodsA cross-sectional study including 100 healthy women without prior thyroid disease, in their first trimester of a singleton pregnancy were recruited from an HMO clinic in central Israel. The women were followed from their first trimester. All women completed a 24-h dietary recall and life habits questionnaires. We tested for UIC, maternal and neonatal thyroid function, maternal autoantibodies, and neonatal outcomes.ResultsMedian UIC in our cohort was 49 µg/L [25%–75% interquartile range (IQR) 16-91.5 µg/L], with 84% below adequacy range. No correlation was found between iodine deficiency and maternal or neonatal thyroid function which remained within normal ranges. Antibody status did not differ, but thyroglobulin levels were significantly higher in iodine insufficient subjects. UIC was higher in women consuming an iodine containing supplement. There was no association between UIC and dietary iodine content or water source.ConclusionsModerate iodine deficiency is common in our healthy pregnant women population. Our data imply that moderate iodine deficiency in pregnancy seem sufficient to maintain normal maternal and neonatal thyroid function.

THE EFFECT OF PROLONGED FEEDING OF GOITROGENS ON THYROID FUNCTION IN RATS

1965 ◽  
Vol 32 (3) ◽  
pp. 341-351 ◽  
Author(s):  
G. D. BROADHEAD ◽  
I. B. PEARSON ◽  
G. M. WILSON
Keyword(s):  
Thyroid Function ◽  
Iodine Content ◽  
Close Correlation ◽  
Potassium Thiocyanate ◽  
Thyroid Stimulating Hormone ◽  
Size Reduction ◽  
Potassium Perchlorate ◽  
Prolonged Feeding ◽  
Stimulating Hormone

SUMMARY Graded doses of propylthiouracil, carbimazole, sulphadiazine, potassium perchlorate and potassium thiocyanate were fed to groups of rats under standardized conditions for 2 months. The rats were given 131I 24 hr. before they were killed, and the thyroid weight, the proportions of labelled iodoaminoacids, and the thyroidal iodine content were determined. All the goitrogens produced increase in thyroid size, reduction of thyroidal iodine content, and an elevation of the monoiodotyrosine: di-iodotyrosine (MIT:DIT) ratio. The tri-iodothyronine: thyroxine (T3: T4) ratio was usually increased. Irrespective of the antithyroid compound used, there was a close correlation between the decrease in thyroidal iodine content and the rise in the MIT:DIT ratio. In further experiments, either thyroid stimulating hormone (TSH) or thyroxine were injected s.c. twice daily for 5 days. TSH decreased the MIT:DIT ratio and increased the amount of labelled T3. Thyroxine increased the MIT:DIT ratio and decreased the amount of T4. It is suggested that when goitrogens were administered for a prolonged period, the pattern of 131I-labelling of iodoaminoacids was dependent on a balance between inhibition of synthesis caused by the goitrogen and stimulation due to TSH. There was increased production of the physiologically more economical T3 in an attempt to compensate for decreased thyroxine formation.

DYNAMIC STUDY OF POST-NATAL THYROID FUNCTION IN THE RAT

1976 ◽  
Vol 83 (4) ◽  
pp. 752-762 ◽  
Author(s):  
E. Vigouroux
Keyword(s):  
Body Weight ◽  
Plasma Concentration ◽  
Thyroid Function ◽  
Rate Constant ◽  
Turnover Rate ◽  
Single Injection ◽  
Iodine Content ◽  
Adult Females ◽  
Maximal Plasma ◽  
Old Rats

ABSTRACT The thyroid function in development was investigated in post-natal rats. The thyroid iodine content rapidly increased from birth (137 ± 26 ng iodine/mg thyroid) up to day 10 (338 ± 42 ng iodine/mg thyroid) then increased more slowly up to day 30 (425 ± 34 ng iodine/mg thyroid). The maximal plasma concentration of thyroxine was observed on day 16 (56.9 ± 3.5 ng T4/ml) and of iodide on day 10 (110.2 ± 12.6 ng I−/ml). The turnover rate constant of extrathyroidal thyroxine was higher at birth (8.0 ± 2.3 %/h) than at any older age studied (average 6 %/h). Thyroxine secretion by the thyroid was more intense before weaning (37 ng hormonal iodine/h/100 g body weight on days 10 and 20) than after weaning (22 ± 6 ng hormonal iodine/h/100 g body weight in 30 days old rats). The peripheral deiodination rate of thyroxine represented about 90 % thyroxine secretion rate in newborn and 10 days old rats and only 40% in adult females. In pre-weaning rats, after a single injection of both [131I]L-T4 and [125I]Na, extrathyroidal radioactivity disappeared more slowly than in 30 days old rats and adult animals. This suggests that iodide concentrations of extrathyroidal tissues are higher before than after weaning.

THE TRANSPLACENTAL PASSAGE OF THYROXINE AND FOETAL THYROID FUNCTION IN THE RAT

1974 ◽  
Vol 75 (4) ◽  
pp. 725-733 ◽  
Author(s):  
Barry Gray ◽  
Valerie Anne Galton
Keyword(s):  
Body Weight ◽  
Thyroid Gland ◽  
Thyroid Function ◽  
Placental Transfer ◽  
Iodine Content ◽  
Perinatal Period ◽  
Maternal Serum ◽  
Transplacental Passage ◽  
Pregnant Rats ◽  
Near Term

ABSTRACT A study has been made of the transplacental passage of thyroxine (T4) in rats when the hormone is present in physiological concentrations, and of the activity of the foetal thyroid gland in the perinatal period. Several aspects of foetal thyroid function were assessed in intact and thyroid-ectomized (TX) pregnant rats maintained with graded doses of T4. A daily dose of 2 μg T4/100 g body weight yielded near normal maternal and foetal serum PBI levels; with a dose of 1 μg the values were slightly low. Both these doses resulted in a decrease in the total and T4 iodine content of the foetal thyroid; an even greater decrease occurred in rats maintained with 5 μg/100 g body weight/day. The rate of uptake of iodine by the foetal gland was significantly depressed by the 2 but not the 1 μg dose. Serum PBI levels in the foetus were related directly to the dose of T4 and inversely with the degree of depression of the thyroid gland. Both maternal and foetal serum PBI levels in the unsupplemented TX rats were at least 60 % of normal and there was evidence of increased secretion of T4 by the foetal thyroid. The data indicate that the placenta is readily permeable to T4 when the hormone is present in maternal serum in doses that are close to physiological. However it was not possible to estimate the extent of the placental transfer of endogenous hormone. Significant foetal thyroid function was evident near term. It is suggested that both the foetal and maternal thyroids contribute to the maintenance of serum T4 levels in the foetus.

scholarly journals Iodine Status and Thyroid Function in a Group of Seaweed Consumers in Norway

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3483
Author(s):  
Inger Aakre ◽  
Lidunn Tveito Evensen ◽  
Marian Kjellevold ◽  
Lisbeth Dahl ◽  
Sigrun Henjum ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Urinary Iodine ◽  
Iodine Content ◽  
Iodine Concentration ◽  
Iodine Intake ◽  
Thyroid Stimulating Hormone ◽  
Urinary Iodine Concentration ◽  
Free Triiodothyronine ◽  
Iodine Status ◽  
Excessive Iodine

Seaweeds, or macroalgae, may be a good dietary iodine source but also a source of excessive iodine intake. The main aim in this study was to describe the iodine status and thyroid function in a group of macroalgae consumers. Two urine samples were collected from each participant (n = 44) to measure urinary iodine concentration (UIC) after habitual consumption of seaweed. Serum thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), and peroxidase autoantibody (TPOAb), were measured in a subgroup (n = 19). A food frequency questionnaire and an iodine-specific 24 h recall were used to assess iodine intake and macroalgae consumption. The median (p25–p75) UIC was 1200 (370–2850) μg/L. Median (p25–p75) estimated dietary iodine intake, excluding macroalgae, was 110 (78–680) μg/day, indicating that seaweed was the major contributor to the iodine intake. TSH levels were within the reference values, but higher than in other comparable population groups. One third of the participants used seaweeds daily, and sugar kelp, winged kelp, dulse and laver were the most common species. Labelling of iodine content was lacking for a large share of the products consumed. This study found excessive iodine status in macroalgae consumers after intake of dietary seaweeds. Including macroalgae in the diet may give excessive iodine exposure, and consumers should be made aware of the risk associated with inclusion of macroalgae in their diet.

scholarly journals Iodine concentration and content measured by dual-source computed tomography are correlated to thyroid hormone levels in euthyroid  patients: a cross-sectional study in China

2019 ◽  
Author(s):  
ZhengTeng Li ◽  
Rui Zhai ◽  
HongMei Liu ◽  
Min Wang ◽  
Dongmei Pan
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Function ◽  
Thyroid Tissue ◽  
Iodine Content ◽  
Iodine Concentration ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Total Iodine ◽  
Cross Sectional ◽  
The Mean

Abstract Background: The aim of this study was to investigate the correlation of the dual energy CT measured iodine concentration and total iodine content with blood measured thyroid parameters. Methods: 43 patients with normal thyroid function at our hospital from August 2017 to October 2019 were included in this retrospective study. Dual energy CT was used to scan the neck of thyroid patients. The mean iodine concentration and thyroid tissue volume were measured to calculate the total iodine content of the thyroid. Relevant tests of triiodothyronine (FT3), total triiodothyronine (TT3), total thyroxine (TT4), free thyroxine (FT4), and thyroid hormone (TSH) were conducted. The correlation of the thyroid mean iodine concentration and total iodine content with blood-measured thyroid function was analysed. Result: The total iodine content in the thyroid was positively correlated with FT3 but negatively correlated with TSH. The mean iodine concentration of the thyroid was positively correlated with both FT3 and TT3. Conclusion : The thyroid iodine content measured by dual energy CT can be used to determine the human iodine nutritional status and evaluate thyroid function, which will facilitate the diagnosis and treatment of thyroid diseases.

scholarly journals Iodine concentration and content measured by dual-source computed tomography are correlated to thyroid hormone levels in euthyroid patients

2019 ◽  
Author(s):  
ZhengTeng Li ◽  
Rui Zhai ◽  
HongMei Liu ◽  
Dongmei Pan
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Function ◽  
Thyroid Tissue ◽  
Iodine Content ◽  
Iodine Concentration ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Total Iodine ◽  
Normal Thyroid Function ◽  
The Mean

Abstract Background: The aim of this study was to investigate the correlation of the dual energy CT measured iodine concentration and total iodine content with blood measured thyroid parameters. Methods: 43 patients with normal thyroid function at our hospital from August 2017 to October 2019 were included in this retrospective study. Dual energy CT was used to scan the neck of thyroid patients. The mean iodine concentration and thyroid tissue volume were measured to calculate the total iodine content of the thyroid. Relevant tests of triiodothyronine (FT3), total triiodothyronine (TT3), total thyroxine (TT4), free thyroxine (FT4), and thyroid hormone (TSH) were conducted. The correlation of the thyroid mean iodine concentration and total iodine content with blood-measured thyroid function was analysed. Result: The total iodine content in the thyroid was positively correlated with FT3 but negatively correlated with TSH. The mean iodine concentration of the thyroid was positively correlated with both FT3 and TT3. Conclusion: The thyroid iodine content measured by dual energy CT can be used to determine the human iodine nutritional status and evaluate thyroid function, which will facilitate the diagnosis and treatment of thyroid diseases.

Sign in / Sign up

Export Citation Format

Share Document