• The Korean Journal of Pharmacology
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• v.17 no.2
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• pp.37-45
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• 1981

The importance of thyroid hormones for the survival of rats in the cold is along-established fact. Hypothyroid animals are unable to survive in a cold environment. It was also reported that acute exposure of rats, guinea pigs and rabbits to cold produced an increased secretion of TSH and thereby thyroid hormone secretion within 10 to 30 min, but this increase of thyroid activity disappeared quite rapidly during warming. However, in human study no significant difference was found in the concentration of $T_4$, TSH and cortisol between summer and winter. But plasma $T_3$ concentration was increased significantly in winter in 56 adult men. On the other hand, it has been also known that catecholamines are important in the maintenance of body temperature of rat exposured to cold. Abundant evidences suggest that the sympathetic nervous system is involved in the activation of nonshivering thermogenesis and that thyroid hormone metabolism and secretion are influenced by catecholamines and consequently by the activity of the sympatheticadrenal system. Many of the metabolic effects of catecholamines are associated with an increase in the level of cAMP mediated through activation of adenylate cyclase which converts ATP to cAMP. Other studies have shown that thyroid hormones affect the amount of adenylate cyclase present in the adipose tissue. On the other hand. it was also reported that a particulate cAMP phosphodiesterase activity in fat cells was modulated by the action of thyroid hormones. The objective of the present study was to determine the interaction between thyroid activity and cyclic nucleotides during acute exposure to cold. Albino rats weighing around 200 g were used as the experimental animal. The room temperature group was kept at $25^{\circ}C$ and the cold-exposured group was kept at $4^{\circ}C$ for 1 week or 2 weeks. Each group was subdivided into three subgroups; control, KI, and MTU group. At the end of experiment the animals were etherized and blood was taken from abdominal aorta for $T_4,\;T_3$ and cyclic nucleotides. The determinations of $T_3,\;T_4$ and cyclic nucleotides were carried out with a radioimmunoassay(RIA) method. The results were summerized as followings. 1) A significant increase of thyroid weight was observed in rats exposured to cold for 2 weeks. Furthermore, in rats administered MTU while to exposure to cold the thyroid weight was also increased significantly. 2) After 2 weeks $T_3$ concentration in the plasma of cold-exposured rats was significantly increased in KI group and MTU group as well as in control group. On the contrary, after 2 weeks of cold exposure $T_4$ level was decreased in control group. 3) In the case of cyclic nucleotides, plasma cAMP was increased in the control group after 1 or 2 weeks of cold exposure. However, cAMP level in plasma was rather significantly decreased in KI group and MTU group as well as in control group.

• The Korea Journal of Herbology
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• v.25 no.3
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• pp.11-18
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• 2010

Object : This study was to evaluate the effect of Ginseng Radix, aqueous extracts of the root part of Panax ginseng on the 6-n-propyl-2-thiouracil(PTU)-induced rat hypothyroidism. Methods : Aqueous extracts of Ginseng Radix(GR; yield = 11.70%) were administered, once day for 42 days from 2 weeks before start of PTU treatment as an oral dose of 300 and 150 mg/kg(body weight), and hypothyroidism was induced by daily subcutaneous treatment of PTU 10mg/kg for 28 days. The changes in the body weight, thyroid gland weights, serum levels of thyroid hormone-thyroid stimulating hormone(TSH), tri-iodothyronine(T3) and thyroxine(T4), total cholesterol, low density lipoprotein(LDL), high density lipoprotein(HDL) and triglyceride, liver antioxidant defense system-lipid peroxidation, $H_2O_2$, superoxide dismutase(SOD) and catalase(CAT) were observed with histopathology of thyroid glands. Results : Results were compared with LevoT4 0.5mg/kg treated rats. GR extracts suppressed the decreases in the body weight, thyroid gland weights, T3 and T4, TG, liver $H_2O_2$ and SOD activities as results of PTU treatment. And GR extracts suppressed the increases of HDL contents, liver CAT activities, thyroid gland weight as results of PTU treatment. In addition, marked hyperplasia of follicular cells with decreases of follicular colloid contentsand sizes were demonstrated at histopathological inspections. However, these PTU-induced histopathological changes related to hypothyroidism were dramatically decreased by treatment of both different dosages of GR extract, respectively Conclusions : This study suggest that GR extracts have favorable effects on the thyroid hormone productions with beneficial effects on the hypothyroidism mediated by the modulatory effects on the antioxidant defense system.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1451-1457
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• 2016

A comparative study was performed to investigate the efficacy of KiFAY as a feed additive on performance parameters, thyroid, and pancreatic hormone levels in broilers. Ninety birds (Vencobb 400) were randomly divided into three groups viz., Control (no DL-methionine supplementation), Treatment1 (containing added DL-methionine) and Treatment 2 (containing KiFAY and without DL-methionine supplementation). The performance parameters (weekly body weight, body weight gain, feed intake, and feed consumption ratio) were recorded and calculated during the whole study of 4 weeks. Analyses of insulin and insulin-like growth factor (IGF 1), triiodothyronine (T3), thyroxine (T4) and thyroid stimulating hormone (TSH) were performed at the end of the study. The results show that birds on supplementation of KiFAY performed significantly (p<0.001) better than other treatments. The weekly body weight, body weight gain, feed in-take and feed consumption ratio improved in KiFAY treated birds. The study found an increase in insulin and IGF1 levels (p<0.001) in KiFAY compared with the other treatments. Serum T3, T4, and TSH levels in the Treatment 2 were higher than other treatments (p<0.001). The KiFAY supplementation was able to improve performance with associated responses at a hormonal level in broilers.

• International journal of thyroidology
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• v.10 no.2
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• pp.71-76
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• 2017

Background and Objectives: The role of thyroid-stimulating hormone (TSH) signaling on osteoblastic differentiation is still undetermined. The aim of this study was to investigate the effects of 5-aza-2'-deoxycytidine (5-azacytidine) on TSH-mediated regulations of osteoblasts. Materials and Methods: MG63, a human osteoblastic cell-line, was treated with 5-azacytidine before inducing osteogenic differentiation using osteogenic medium (OM) containing L-ascorbic acid and ${\beta}$-glyceophosphate. Bovine TSH or monoclonal TSH receptor stimulating antibody (TSAb) was treated. Quantitative real-time PCR analyses or measurement of alkaline phosphatase activities were performed for evaluating osteoblastic differentiation. Results: Studies for osteogenic-related genes or alkaline phosphatase activity demonstrated that treatment of TSH or TSAb alone had no effects on osteoblastic differentiation in MG63 cells. However, treatment of 5-azacytidine, per se, significantly increased osteoblastic differentiation and combination treatment of 5-azacytidine and TSH or TSAb in the condition of OM showed further significant increase of osteoblastic differentiation. Conclusion: Stimulating TSH signaling has little effects on osteoblastic differentiation in vitro. However, in the condition of epigenetic modification using inhibitor of DNA methylation, TSH signaling positively affects osteoblastic differentiation in human osteoblasts.

• The Korean Journal of Nuclear Medicine
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• v.17 no.2
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• pp.1-17
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• 1983

The purpose of this study is to investigate the effects of thyroid hormone on the left ventricular(LV) volume arid function in man with untreated hyperthyroidism and to determine the effects of successful therapy for thyrotoxicosis on the ventricular pathophysiology. In the present study, equilibrium radionuclide cardiac angiography was performed and LV volume index, ejection phase indexes of LV performance, serum thyroid hormone levels and other hemodynamic parameters were measured in 28 normal subjects and 39 patients with hyperthyroidism before treatment and again every 4 weeks for the first 2 months after the initiation of effective therapy. The results obtained were as follows; 1) In the untreated hyperthyroid state heart rate, blood volume, cardiac index and stroke volume index($97{\pm}14$ beats/min, $73.5{\pm}11.8ml/kg,\;6.9{\pm}1.4\;l/min/m^2$ and $77.6{\pm}13.8ml/m^2$, respectively) were increased significantly compared to those in normal control($74{\pm}12beats/min$, $66.6{\pm}14.8ml/kg,\;3.8{\pm}1.2\;l/min/m^2$ and $56.6{\pm}13.2ml/m^2$ respectively). $(Mean{\pm}SD)$ 2) There was a significant increase in LV end-diastolic volume index in patients with hyperthyroidism ($30.5{\pm}7.5$ for hyperthyroid group compared to a normal control of $22.2{\pm}6.5$; p<0.001), whereas end-systolic volume index remained unchanged $9.6{\pm}3.6\;and\;8.8{\pm}3.3$ respectively).3) In patients with hyperthyroidism, LV ejection fraction was $70.0{\pm}5.6%$, fractional shortening $32.9{\pm}5.1%$, mean velocity of circumferential fiber shortening(mean Vcf) $1.34{\pm}0.31$ circ/sec and maximum ejection rate $3.47{\pm}0.80$. All the ejection phase indexes were significantly greater than those in normal control($65.2{\pm}5.7%,\;28.8{\pm}3.2%,\;0.88{\pm}0.37$ circ/see and $2.27{\pm}0.50$, respectively; p<0.001). 4) Effective therapy produced significant decrease in all the values of serum thyroid hormone concentrations(p<0.00l), hemodynamic parameters(p<0.001), end-diastolic volume index(p<0.01) and ejection phase indexes of LV contractility in patients with hyperthyroidism and after one to two months, when the patients were euthyroid, these measurements were in the range of normal. 5) A significant linear correlation between mean Vcf and serum thyroxine level(r=0.63, p<0.001) as well as between mean Vcf and serum triiodothyronine level(r=0.62, p<0.001) was found. The lesser degree of correlation was also noted between other ejection phase indexes and serum thyroid hormone concentrations. The results indicate that the major effects of excess thyroid hormone on the LV in human beings with hyperthyroidism are an enhancement of LV function and an increase in LV enddiastolic volume and that these effects cause predictable reversible cardiac alteration which are changed dramatically and immediately after effective therapy.

• 대한핵의학회:학술대회논문집
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• 2002.05b
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• pp.77-95
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• 2002

During the last several decades, prognosis of differentiated thvroid cancers improved markedly, mainly due to refinement of surgical techniques and routine use of radioactive iodine. Total or neat-total thyroidectomy is to be performed as the first line of treatment. Routine remnant ablation just after surgery decreases recurrence and increases survival. After then patients are maintained on suppressive dose of thyroid hormone to keep endogenous TSH below normal. Regular follow-up of the patients with serum thyroglobulin measurement and iodine whole body scan after thyroid hormone withdrawal or under recombinant human thyrotropin stimulation select high risk patients with recurrence or metastatic disease and treatment with therapeutic dose of radioactive iodine prolongs survival and sometimes leads cure. Currently recommended diagnostic and therapeutic strategies, present controversies and future directions are discussed.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.1
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• pp.28-37
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• 2022

Pregnancy requires an important interpretation of thyroid function tests. The presence of anti-thyroid antibodies and viral infectious agents affect the health of both the fetus and the mother. Hence, a selective evaluation of thyroid function in pregnancy is required. This study is a retrospective cross-sectional survey to examine the correlation between thyroid hormones and viral infections during pregnancy. The results showed that the triiodothyronine (T3) decreased with increasing age, especially in the hepatitis C virus (HCV)-positive group (P<0.01). In addition, although negative for the human immunodeficiency virus (HIV), thyroxine (FT4) showed a significant increase in near-threshold or twin pregnant women (P<0.05). The thyroid stimulating hormone (TSH) was highly distributed at the age of 30, and there was no statistically significant correlation with other viral infection factors. In addition, as a result of dividing and analyzing the result of TSH by the quantiles, FT4 and T3 showed a positive correlation but showed a negative correlation with TSH (P<0.05). Therefore, the evaluation of prenatal thyroid screening during pregnancy and viral infection factors should reflect the time of pregnancy, exposure to infection, and the quantitative values. Adequate thyroid hormone and viral infections availability is important for an uncomplicated pregnancy and optimal fetal development.

• Journal of Nutrition and Health
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• v.32 no.4
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• pp.369-375
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• 1999

Hyperthroidism in known to alter the activity of a number of enzymes involved in the catabolism of histidine to CO2. 10-Formyltetrahydrofolate dehydrogenase(EC 1.5, 1.6, 10-formyl-THE dehydrogenase) catalyzes the NADP-dependent conversion of 10-formyltetrahydrofolate to tetrahydrofolate and CO2. In previous studies, 10-formyl-THF dehydrogenase purified from rat and pig liver was coidentified with the cytosolic folate-binding protein. In this study, we investigated the effects of feeding thyroid powder (TP) and thiouracil(TU) on the folate-binding properties of 10-formyl-THE dehydrogenase, the uptake of an injected dose of [3H] folate, and the metabolism of labeled folate to pteroylopoly-${\gamma}$-glutamate in rat liver. The initial hepatic uptake(24hr) of the labeled folate dose was higher in TU-rats and slightly higher in TP-rats in controls. With longer time periods, decreased hepatic uptake of labeled folate was observed in TP-animals compared to euthroid animals, and high levels of hepatic uptake of labeled folate were maintained in TU-animals. This data shows that high levels of thyroid hormone decreased the retention of folate in rat liver. Folate polygutamate chain length was shorter in TU-rats than controls, which suggests that thyroid states do not affect the ability to synthesize pteroylpolyglutamates and that folate polyglutamate might be modulated by altered folate pool size. The ability of 10-formyl-THE dehydrogenase to bind folate in rat liver was similar in both TP-and TU-rats although dehydrogenase activity was changed by thyroid sates.

• The Korean Journal of Nuclear Medicine
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• v.12 no.2
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• pp.41-46
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• 1978

8 cases of subacute thyroiditis was diagnosed among 108 needle biopsy of the thyroid during the period from April 1976 to August 1978. Correlation of the histologic findings with the clinical staging proposed by Czernick was relatively well matched; cases with long clinical course or low thyroid hormone levels showed greater fibrosis and reduction of follicular elements in thyroid. Thyroid $^{131}I$ uptake or the uptake as seen on the thyroid scanning correlated inversely with the thyroid hormone levels. The clinical course of the patients seen in their initial stage of disease followed the classical pattern; hyperthyroid-like, hypothyroid-like and recovery. 3 among the 4, who were seen in their later clinical course showed hypothyroidism, which seemed the final outcome of their diseases.

• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.195-195
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• 2005