RESUMO
Adequate iodine nutrition is fundamental for all humans and is critical during pregnancy and lactation due to iodine forms part of the structure of thyroid hormones (THs) and it is required for THs function. Iodine is a scarce micronutrient that must be obtained from the diet. Sufficient iodine can be found in the nature from seafood and given it is not frequently consumed by Chileans, public health policies state that table salt in Chile must be iodized. Health plans must be monitored to determine if the intake of iodine is being appropriated and the population has not fallen in deficiency or excess. The aim of this work was to evaluate iodine intake in 26 women at the third trimester of pregnancy. Pregnant women are resident from El Bosque a low-income County located in Santiago de Chile. These Chilean pregnant women were recruited by nutritionist at the Centros de Salud familiar (CESFAM). A 24 h dietary recall (24 h-DR) was applied to them to evaluate iodine intake. Samples of urine and blood were taken by health professionals to analyze parameters of thyroid function and to measure urine iodine concentration (UIC). The survey analysis showed that the iodine consumption in these pregnant women derived mainly from salt, bread and milk and not from seafood. The survey analysis indicated that iodine intake was above the requirements for pregnant women. However, the average UIC indicated that iodine intake was adequate, suggesting the need to find a better parameter to determine iodine intake in pregnant women.
Assuntos
Iodo , Terceiro Trimestre da Gravidez , Humanos , Feminino , Gravidez , Iodo/sangue , Iodo/urina , Terceiro Trimestre da Gravidez/sangue , Terceiro Trimestre da Gravidez/urina , Ingestão de Alimentos , Chile , Estudos de Coortes , Pobreza , Glândula Tireoide/fisiologiaRESUMO
The hypothalamus-pituitary-thyroid-axis (HPT) is one of the main neuroendocrine axes that control energy expenditure. The activity of hypophysiotropic thyrotropin releasing hormone (TRH) neurons is modulated by nutritional status, energy demands and stress, all of which are sex dependent. Sex dimorphism has been associated with sex steroids whose concentration vary along the life-span, but also to sex chromosomes that define not only sexual characteristics but the expression of relevant genes. In this review we describe sex differences in basal HPT axis activity and in its response to stress and to metabolic challenges in experimental animals at different stages of development, as well as some of the limited information available on humans. Literature review was accomplished by searching in Pubmed under the following words: "sex dimorphic" or "sex differences" or "female" or "women" and "thyrotropin" or "thyroid hormones" or "deiodinases" and "energy homeostasis" or "stress". The most representative articles were discussed, and to reduce the number of references, selected reviews were cited.
Assuntos
Metabolismo Energético/fisiologia , Sistema Hipotálamo-Hipofisário/fisiologia , Caracteres Sexuais , Estresse Fisiológico/fisiologia , Glândula Tireoide/fisiologia , Adaptação Fisiológica/fisiologia , Animais , Feminino , Humanos , MasculinoRESUMO
There is evidence about a possible relationship between thyroid abnormalities and gestational diabetes mellitus (GDM). However, there is still no conclusive data on this dependence, since no strong correlation has been proved. In this work, we used machine learning to determine whether there is a correlation between maternal thyroid profile in first and second trimester of pregnancy and GDM. Using principal component analysis, it was possible to find an evident correlation between both, which could be used as a complement for a more sensitive GDM diagnosis.
Assuntos
Diabetes Gestacional/sangue , Hormônios Tireóideos/sangue , Adulto , Diabetes Gestacional/epidemiologia , Feminino , Humanos , Aprendizado de Máquina , Testes para Triagem do Soro Materno/estatística & dados numéricos , Gravidez , Primeiro Trimestre da Gravidez/sangue , Segundo Trimestre da Gravidez/sangue , Análise de Componente Principal , Fatores de Risco , Testes de Função Tireóidea/estatística & dados numéricos , Glândula Tireoide/fisiologia , Hormônios Tireóideos/análiseRESUMO
Introducción: La microscopía holográfica digital ha permitido a la microscopía óptica hacer uso de herramientas numéricas y computacionales; y esto, a su vez, ha favorecido múltiples avances en el estudio de las células y los tejidos en diferentes campos de la medicina y otras ciencias afines. Objetivo: Describir las características histológicas y morfométricas de los folículos tiroideos humanos con la microscopía holográfica digital. Métodos: Se realizó, desde el punto de vista histomorfométrico, un estudio descriptivo y transversal de folículos tiroideos humanos utilizando una instalación de microscopía holográfica digital. Se empleó la técnica de inclusión en parafina y tinción de hematoxilina-eosina para el procesamiento de las muestras. Se realizaron de 10 a 12 capturas de hologramas por muestra y el método de doble propagación para la reconstrucción de los hologramas. Se calculó el área, el perímetro, el diámetro mayor y menor de los folículos y cavidades foliculares y se realizaron reconstrucciones de imágenes holográficas en tres dimensiones. Se determinó como medida de tendencia central la media aritmética y como medida de dispersión la desviación típica o estándar. Resultados: Parámetros foliculares: área (5140,31 ± 1126,71 µm2); perímetro (2961,54 ± 71,2 µm); diámetro mayor:(921,17 ± 24,34 µm); diámetro menor: (746,67 ± 18,08 µm); altura del epitelio (7,92 ± 0,96). Cavidades foliculares: área (3686,18 ±1023,52 µm2); diámetro mayor: (698,86 ± 19,55 µm) y diámetro menor: (581,15 ± 13,82 µm). Conclusiones: Existen parámetros foliculares, determinados mediante la microscopía holográfica digital, no reportados por la literatura consultada, que resultan de interés en el estudio histológico de los folículos tiroideos humanos(AU)
Introduction: Digital holographic microscopy has made it possible to incorporate the use of numerical and computer tools into optical microscopy. This in turn has led to great progress in the study of cells and tissues in several fields of medicine and related sciences. Objective: Describe the histological and morphometric characteristics of human thyroid follicles using digital holographic microscopy. Methods: A descriptive cross-sectional histomorphometric study was conducted of human thyroid follicles using a digital holographic microscopy facility. Sample processing was based on inclusion technique by paraffin and hematoxylin-eosin staining. Ten to twelve holographic captures were made per sample, and the double propagation method was used for holographic reconstruction. Estimation was carried out of the area, perimeter, and greatest and smallest diameter of follicles and follicular cavities, and tri-dimensional reconstructions were made of holographic images. Arithmetic mean was determined as the measure of central tendency, and typical or standard deviation as the measure of dispersion. Results: Follicular parameters: area (5 140.31 ± 1 126.71 µm2); perimeter (2 961.54 ± 71.2 µm); greatest diameter (921.17 ± 24.34 µm); smallest diameter (746.67 ± 18.08 µm); epithelial height (7.92 ± 0.96). Follicular cavities: area (3 686.18 ± 1 023.52 µm2); greatest diameter (698.86 ± 19.55 µm); smallest diameter (581.15 ± 13.82 µm). Conclusions: A number of follicular parameters determined by digital holographic microscopy have not been reported by the literature consulted, and they are of interest to the histological study of human thyroid follicles(AU)
Assuntos
Humanos , Computadores , Holografia/métodos , Hematoxilina/uso terapêutico , Glândula Tireoide/fisiologia , Amarelo de Eosina-(YS)RESUMO
Previous studies indicate that leptin regulates the hypothalamic-pituitary-thyroid (HPT) axis via direct and indirect mechanisms. The indirect mechanism involves leptin action in pro-opiomelanocortin (POMC)- and agouti-related peptide (AgRP)-expressing neurones. These cells innervate the paraventricular nucleus of the hypothalamus (PVH) where they modulate hypophysiotrophic thyrotrophin-releasing hormone (TRH)-producing neurones. The direct mechanism involves the expression of leptin receptor (LepR) in a subpopulation of PVH TRH neurones. However, to our knowledge, the existence of LepR in PVH TRH neurones of mice has not been clearly confirmed. Therefore, we investigated possible species-specific differences between rats and mice with respect to the mechanisms recruited by leptin to regulate the HPT axis. We observed that an acute leptin injection induced phosphorylated signal transducer and activator of transcription 3 (pSTAT3), a marker of leptin-responsive cells, in 46.2 ± 8.0% of PVH proTRH immunoreactive neurones in rats. By contrast, an insignificant number of proTRH positive neurones in the mouse PVH co-expressed leptin-induced pSTAT3 or LepR. Similarly, central leptin injection increased the percentage of PVH proTRH neurones containing cAMP response element-binding protein phosphorylation in rats, but not in mice. We investigated the innervation of AgRP and POMC axons in the PVH and observed that rats exhibited a denser POMC innervation in the PVH compared to mice, whereas rats and mice showed similar density of AgRP axons in the PVH. In conclusion, rats and mice exhibit important species-specific differences in the direct and indirect mechanisms used by leptin to regulate the HPT axis.
Assuntos
Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Leptina/farmacologia , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Glândula Tireoide/efeitos dos fármacos , Animais , Sistema Hipotálamo-Hipofisário/fisiologia , Leptina/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Núcleo Hipotalâmico Paraventricular/metabolismo , Ratos , Ratos Long-Evans , Receptores para Leptina/genética , Receptores para Leptina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Especificidade da Espécie , Glândula Tireoide/fisiologia , Hormônio Liberador de Tireotropina/metabolismoAssuntos
Hormônio do Crescimento/sangue , Hormônio do Crescimento/deficiência , Hormônio do Crescimento/uso terapêutico , Pediatria/história , Glândula Tireoide/fisiologia , Tireotropina/uso terapêutico , Criança , Feminino , História do Século XX , Humanos , Iodo/uso terapêutico , Estudos ProspectivosRESUMO
There is a lack of information correlating low adiposity with hypertension experienced by Spontaneous Hypertensive Rats (SHR) or overweight and normotension in Wistar-Kyoto (WKY). We aimed to investigate this lipodystrophy phenomenon by measuring fluorescence lifetime (FLIM), optical redox ratio (ORR), serum levels of hypothalamic-pituitary-adrenal (HPA) and/or hypothalamic-pituitary-thyroid (HPT) hormones axes between Wistar, WKY and SHR before and after establishment of hypertension. Under high blood pressure, we evaluated serum adipokines. Brown adipose tissue was characterized as lower ORR and shorter FLIM compared to white adipose tissue. HPT axis showed a crucial role in the SHR adipose tissue configuration by attenuating whitening. The increased adiposity in WKY may act as a preventive agent for hypertension, since SHR, with low adiposity, establishes the disease. The hypertensive environment can highlight key adipokines that may result in new therapeutic approaches to the treatment of adiposity dysfunctions and hypertension.
Assuntos
Tecido Adiposo Marrom/fisiologia , Tecido Adiposo/fisiologia , Hipertensão , Lipodistrofia , Adipocinas/sangue , Tecido Adiposo/diagnóstico por imagem , Tecido Adiposo/metabolismo , Tecido Adiposo Marrom/diagnóstico por imagem , Animais , Pressão Sanguínea/fisiologia , Hipertensão/complicações , Hipertensão/diagnóstico por imagem , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Sistema Hipotálamo-Hipofisário/diagnóstico por imagem , Sistema Hipotálamo-Hipofisário/fisiologia , Lipodistrofia/diagnóstico por imagem , Lipodistrofia/etiologia , Lipodistrofia/fisiopatologia , Masculino , Microscopia de Fluorescência/métodos , Oxirredução , Sistema Hipófise-Suprarrenal/diagnóstico por imagem , Sistema Hipófise-Suprarrenal/fisiologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/fisiologiaRESUMO
BACKGROUND: Thyroid cancer incidence has been increasing, acquiring a greater importance in health, especially of women, who are more frequently affected. As 17-ß-estradiol (E2) has been shown to have a proliferative effect on benign and malignant thyroid cells, G protein-coupled estrogen receptor (GPER1) could have a role on the pathogenesis of thyroid cancer. OBJECTIVE: To evaluate data on GPER1 in the thyroid. DATA SOURCES: PubMed, Scielo and Cochrane Library databases were searched, using the keywords GPER1 or GPR30 or GPER and thyroid, since the inception until Jun, 2019. Other sources were used, as cross-referencing. STUDY SELECTION: All studies which evaluated GPER1 GPER1 or GPR30 or GPER in the thyroid. DATA EXTRACTION: From 23 articles identified, eight studies were included: one in commercial samples of human thyroid, four in human thyroid cancer cell lines, and three in human samples of benign and/or malignant thyroid diseases. DATA SYNTHESIS: GPER1 gene and protein expression were described, respectively, in six and five studies, and the results varied according to the study. In three studies, increased proliferation of four thyroid cancer cell lines were induced by E2, with evidences suggesting that GPER1 at least partially mediated growth in these cells. GPER1 was identified in the cell membrane, in three studies, and in the cytoplasm in two studies. CONCLUSIONS: The paucity of studies about GPER1 in the thyroid, as well as methodological differences between them, precludes firm conclusions about GPER1 role in the thyroid, although there are some evidences of GPER1-induced proliferation of thyroid cancer cells.
Assuntos
Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Glândula Tireoide/fisiologia , Neoplasias da Glândula Tireoide/metabolismo , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Receptores de Estrogênio/genética , Receptores Acoplados a Proteínas G/genética , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologiaRESUMO
Thyroid hormones play an important role in body homeostasis by facilitating metabolism of lipids and glucose, regulating metabolic adaptations, responding to changes in energy intake, and controlling thermogenesis. Proper metabolism and action of these hormones requires the participation of various nutrients. Among them is zinc, whose interaction with thyroid hormones is complex. It is known to regulate both the synthesis and mechanism of action of these hormones. In the present review, we aim to shed light on the regulatory effects of zinc on thyroid hormones. Scientific evidence shows that zinc plays a key role in the metabolism of thyroid hormones, specifically by regulating deiodinases enzymes activity, thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH) synthesis, as well as by modulating the structures of essential transcription factors involved in the synthesis of thyroid hormones. Serum concentrations of zinc also appear to influence the levels of serum T3, T4 and TSH. In addition, studies have shown that Zinc transporters (ZnTs) are present in the hypothalamus, pituitary and thyroid, but their functions remain unknown. Therefore, it is important to further investigate the roles of zinc in regulation of thyroid hormones metabolism, and their importance in the treatment of several diseases associated with thyroid gland dysfunction.
Assuntos
Glândula Tireoide/fisiologia , Hormônios Tireóideos/metabolismo , Hormônio Liberador de Tireotropina/fisiologia , Tireotropina , Zinco , Hormônios Tireóideos/química , Hormônio Liberador de Tireotropina/químicaRESUMO
Cell therapy with mesenchymal stem cells (MSC) has been proposed for the treatment of diabetes mellitus (DM). It is known that the prevalence of thyroid disease is higher among diabetic patients than in general population. Therefore, our aim was to investigate the effect of the treatment with MSC on thyroid function and ROS generation in an experimental model of type 1 DM. Adult male Wistar rats were divided into the following groups: control, DM (80 mg/kg BW streptozotocin, iv.) and DM+MSC. MSC treatment occurred 4 weeks after DM induction and the animals were euthanized 4 weeks after MSC administration. We also evaluated the effect of co-culture with MSC or extracellular vesicles (EV) obtained from these cells on the rat thyroid cell line PCCL3 exposed to high glucose. Thyroid H2O2 generation was increased in DM, which was reversed by MSC treatment. These changes paralled a significant DuOx1 mRNA increase. The incubation of PCCL3 with high glucose increased extracellular H2O2 generation, which was reversed by both the co-culture with MSC and EV. Even though MSC treatment normalized thyroid ROS generation, serum thyroid hormone (TH) concentration remained low, along with increased serum TSH concentrations. Thyroperoxidase (TPO) activity, was reduced in DM, and MSC treatment did not normalize TPO. Therefore, we conclude that the treatment with MSC was able to reverse the increased thyroid H2O2 generation in diabetic animals and in PCCL3 cells exposed to high glucose, an effect probably mediated by EV produced by these cells, acting in a paracrine fashion.