• The Korean Journal of Pesticide Science
• /
• v.12 no.4
• /
• pp.342-350
• /
• 2008

This study was carried out to investigate the suitability of the pubertal assay and the enhanced TG 407 as methods for detection of endocrine-mediated effects. Thyroid function was also considered. Male and female Sprague-Dawley rats were gavaged daily with 0, 25, 50, 100 mg/kg metribuzin in corn oil during 30 days. The effects of metribuzin on thyroid gland, the genital organs and thyroid hormone were measured in male and female rats. Dose of metribuzin 50 mg/kg/day increased relative weight of testis, prostate, and seminal vesicle in male rats but relative weight of thyroid gland was not significantly different from control group. Dose of metribuzin 25 mg/kg/day decreased relative weight of thyroid gland in female rats. Another purpose of this study was to investigate the effects of endocrine-disruptors as like thyroid hormone in vitro. Luciferase activity was measured to detect reaction of test chemicals and thyroid hormone response elements in HeLaTRE cell. Dose of metribuzin from 1 to 1,000 nM increased to 106-122% of luciferase activity.

• The Korean Journal of Pesticide Science
• /
• v.12 no.3
• /
• pp.207-214
• /
• 2008

This study was designed to investigate the suitability of the pubertal assay and the enhanced TG 407 as methods for detection of endocrine-mediated effects, especially thyroid function. Male and female Sprague-Dawley rats were gavaged daily with 0, 12.5, 25, 50 mg/kg alachlor in corn oil during 30 days. The effects of alachlor on thyroid gland, the genital organs and thyroid hormone were measured in male and female rats. Dose of alachlor 25, 50 mg/kg/day increased relative weight of testis and thyroid gland in exposed male rats and decreased relative weight of vagina in exposed female rats. Relative weight of thyroid gland was decreased in alachlor 25 mg/kg/day exposed female rats. Dose of alachlor 25, 50 mg/kg/day decreased plasma T4 and testosterone in female rats. Another purpose of this study was to investigate the effects of endocrine disruptors as like thyroid hormone in vitro. Luciferase activity was measured to dectect reaction of test chemicals and thyroid hormone response elements in HeLaTRE cell. Dose of alachlor 1 nM-1000 nM increased 100-134% luciferase activity compared with control.

• Journal of Korean Academy of Nursing
• /
• v.13 no.2
• /
• pp.87-104
• /
• 1983

It has been well documented that animals exposed to cold show increased activity of thyroid gland. The calorigenic action of thyroid hormone has been demonstrated by a variety of in vivo and in vitro studies. According to Edelman et al., the thyroid thermogenesis is due to activation of energy consuming processes, especially the active sodium transport by the hormone in target tissues. If so, the increase in thyroid activity during cold exposure should induce increased capacity of sodium transport in target tissue and the change in tissue metabolism should be precisely correlated with the change in Na+_K+_ATPase activity of the tissue. This possibility was tested in the present study: in one series, changes in oxygen consumption and Na+_K+_-ATPase activity of liver preparations were measured in rats as a function of thyroid status, in order to establish the effect of thyroid hormone on the tissue respiration and enzyme system in another series, the effect of cold stimulus on the serum thyroid hormone level, hepatic tissue oxygen consumption and Na+_K+_ATPase activity in rats. The results obtained are as follows: 1. The Na+_dependent oxygen consumption of liver slices, the oxygen consumption of liver mitochondria and the Na+_K+_ATPase activity of liver preparations were significantly inhibited in hypothyroidism and activated in hyperthyroidism. Kinetic analysis indicated that the Vmax. of Na+_K+_ATPase was decreased in hypothyroidism and increased in hyperth)'roidism. 2. In cold exposed rats, the serum triiodothyronine (T₃) level increased rapidly during the initial one day of cold exposure, then declined slowly to the control level after two weeks. The serum thyroxine (T₄) level decreased gradually throughout the cold exposure. Accordingly the T₃/T₄ratio increased. The mitochondrial oxygen consumption and the Na+_dependent oxygen consumption of liver slices increased during the first two days and then remained unchanged thereafter The activity of the Na+_K+_ATPase in liver preparations increased during cold exposure with a time course similar to that of oxygen consumption. Kinetic analysis indicated that the Vmax. of Na+_K+_ATPase increased. 3. Once the animal was adapted to cold, induction of hypothyroidism did not significantly alter the hepatic oxygen consumption and Na+_K+_ATPase activity. These results indicate that: 1) thyroid hormone increases capacities of mitochondrial respiration and active sodium transport in target tissues such as liver; 2) the increased T₃level during the initial period of cold exposure facilitates biosynthesis of Na+_K+_ATPase and mitochondrial enzymes for oxidative phosphorylation, leading to enhanced production and utilization of ATP, hence heat production.

• Annals of Pediatric Endocrinology and Metabolism
• /
• v.23 no.4
• /
• pp.169-175
• /
• 2018

Thyroid dyshormonogenesis is characterized by impairment in one of the several stages of thyroid hormone synthesis and accounts for 10%-15% of congenital hypothyroidism (CH). Seven genes are known to be associated with thyroid dyshormonogenesis: SLC5A5 (NIS), SCL26A4 (PDS), TG, TPO, DUOX2, DUOXA2, and IYD (DHEAL1). Depending on the underlying mechanism, CH can be permanent or transient. Inheritance is usually autosomal recessive, but there are also cases of autosomal dominant inheritance. In this review, we describe the molecular basis, clinical presentation, and genetic diagnosis of CH due to thyroid dyshormonogenesis, with an emphasis on the benefits of targeted exome sequencing as an updated diagnostic approach.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2004.12a
• /
• pp.86-87
• /
• 2004

• Medical Lasers
• /
• v.10 no.1
• /
• pp.37-44
• /
• 2021

Background and Objectives Hypothyroidism is the most common endocrine disease. On the other hand, there is no treatment that can improve the thyroid function. Low-level laser therapy (LLLT) can improve the cellular activity. The effect of hypothyroidism is not obvious. This study examined the effects of LLLT on the thyroid gland function of a propylthiouracil (PTU)-induced hypothyroidism mouse model. Materials and Methods Twenty-five male ICR mice were distributed into five groups of five animals each: Negative control (none PTU animal) and positive control (PTU animal) of unirradiated animals, and three experimental groups with LLLT (3J, 6J, and 12J). Each mouse was exposed to a distinct dose of a 632-nm laser once a week for three rounds. The positive control group and three LLLT groups were induced into a hypothyroidism state by PTU administration. The animals' thyroid-stimulating hormone and thyroxine levels were measured using an ELISA kit, and their thyroid tissue was harvested and analyzed after sacrifice at the end of the experiment. The hormone level and morphological changes in the tissue of the five groups were compared. Results The thyroid hormone levels in the control group and LLLT groups were similar. On the other hand, the thyroid tissue of the LLLT groups showed some morphological changes that were similar to those of iodine deficiency thyroid. Conclusion LLLT did not affect the thyroid gland function in PTU-induced hypothyroidism mice.

• Clinical and Experimental Pediatrics
• /
• v.63 no.2
• /
• pp.52-55
• /
• 2020

Background: Immunomodulatory properties of interferon (IFN) have been documented. It may induce autoimmune diseases such as autoimmune thyroiditis with hypo- or hyperthyroidism. In addition, it may impair thyroid hormone synthesis through affecting iodide organification in thyroid gland. Purpose: The aim of this study was to describe thyroid function tests disturbances in children with chronic hepatitis C (CHC) receiving pegylated interferon-alpha (PEG IFN-α) plus ribavirin. Methods: Fifty children with CHC virus infection who received combined pegylated interferon-alpha with ribavirin were selected. Other 50 apparently healthy children of matched age and sex (considered as control group) were selected. All children (100) were subject to liver function tests, virological studies, and follow-up of thyroid function test during and after the treatment course. Results: Our study showed that 28% of children received combined PEG IFN-α plus ribavirin showed subclinical hypothyroidism. After 24 weeks treatment with combined therapy of IFN plus ribavirin, the mean level of thyroid stimulating hormone (TSH) was 3.23±88 mU/mL, while TSH was 1.16±0.77 mU/mL before starting treatment. On the other hand, mean TSH was 1.09±0.92 mU/mL in normal control group. Conclusion: This study revealed an association between subclinical thyroid dysfunction and treatment with IFN-alpha and ribavirin in children. Further studies on larger number of patients and longer follow-up duration are recommended for further confirmation.

• The Journal of Internal Korean Medicine
• /
• v.26 no.1
• /
• pp.213-220
• /
• 2005

Objective : Thyroid diseases are one of the most common endocrine disorders. However, the first chosen-treatments including anti-thyroidal and hormone-supplement therapy in western medicines, sometimes have failed to improve abnormal thyroid hormone secretions and clinical symptoms. Therefore, there has been a growing expectation for Oriental Medicine to take the role of alternative therapy. However, there has been little analysis of clinical characteristics. In this study, clinical characteristics of thyroidal disease patients who visited Kyung-Hee oriental hospital from January to July 2004 were analyzed. Methods : A total 86 patients diagnosed as hyperthyroidism, hypothyroidism or thyroid nodule were selected. Clinical history, including sex, age, symptoms, disease duration and methods of previous therapy and thyroidal test, such as thyroid function test (TFT), thyroid scan and other thyroid examinations. Results : In distribution of onset age and sex, the patients who have visited oriental hospital with thyroidal diseases showed similar characteristics with typical patients. In clinical symptom, the most frequent clinical sign was fatigue in both hyperthyroidism and hypothyroidism, which differs from the classical characteristics of those diseases. Most patients complained the unresolved symptoms, some of which are attributable to abnormal thyroid hormone secretions, in spite of western therapy with anti-thyroidal and hormone supplement agents. Conclusions : In oriental therapy, it will be necessary to consider the unique clinical features of thyroidal diseases different from classical patterns, and this study suggests that oriental therapy is a good alternative method for patients whose first treatment with western agents failed. Furthermore, more public information to these patients about oriental medicine would be helpful to increase cure rates, and give various choices to patients with thyroid diseases.

• Biomedical Science Letters
• /
• v.14 no.1
• /
• pp.59-62
• /
• 2008

This experiment was performed to study the effect of TSH (thyroid-stimulating hormone) on the expression of endoplasmic reticulum (ER) chaperones in the rat thyrocytes FRTL-5 cells. Although the expressions of ER membrane kinases (ATF6, IRE1 and PERK) were specially enhanced under absence of TSH, no remarkable up- or down regulations of ER chaperones (BiP, CHOP and Calnexin) were detected by TSH. We firstly report here that TSH by dose up-regulated expression of ER membrane kinases in FRTL-5 culture thyrocytes.

• Korean Journal of Clinical Laboratory Science
• /
• v.49 no.3
• /
• pp.203-213
• /
• 2017

Serum creatinine-based eGFR and serum cystatin C-based eGFR are the most popular methods for measuring renal function. Thyroid hormone is known to affect serum creatinine-based eGFR and serum cystatin C-based eGFR; however, the clinical significance of thyroid dysfunctional patients of renal function evaluation has not been fully elucidated to date. This study examined the effect of thyroid hormone on serum creatinine-based eGFR and serum cystatin C-based eGFR. Moreover, we also evaluated the correlation analysis between serum creatinine-based eGFR and serum cystatin C-based eGFR in patients with thyroid dysfunction. A total of 442 patients with hypothyroidism and 284 patients with hyperthyroidism were investigated. A correlation analysis between thyroid hormone and serum creatinine- (and cystatin C-) based eGFR was performed. A correlation analysis between thyroid hormone and serum cystatin-C based eGFR indicated that serum cystatin-C based eGFR is more of an independent biomarker than serum creatinine-based eGFR in thyroid dysfunction patients. Therefore, serum cystatin C-based eGFR more accurately reflects renal function than serum creatinine-based eGFR in thyroid dysfunction patients.