Mediobasal hypothalamic and adenohypophyseal TRH‐degrading enzyme (PPII) is down‐regulated by zinc deficiency

Alvarez-Salas, Elena; Alcántara-Alonso, Viridiana; Matamoros-Trejo, Gilberto; Vargas, Miguel; Morales-Mulia, Marcela; Gortari, Patricia de

doi:10.1016/j.ijdevneu.2015.08.001

Cited by 13 publications

(22 citation statements)

References 81 publications

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“…Normal thyroid function depends on the presence of many trace elements which synthesize and metabolize thyroid hormones [1,2]. Additionally, iodine and some trace elements are involved in the thyroid hormone metabolism [3].…”

Section: Introductionmentioning

confidence: 99%

“…Zinc is an indispensable element in the functioning of 1,5′-deiodinase, which is required for the conversion of T 4 to T 3 , its active form, [6]. Zinc is necessary not only for the functioning of thyroid hormones, but also for the synthesis of TSH from hypophysis and TRH from hypothalamus [1,7]. In their study, Wada and King [8] examined for the first time the relationship between zinc values and thyroid hormone values and discovered the effect of zinc supplementation on thyroid hormone functions.…”

Section: Introductionmentioning

confidence: 99%

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Changes in the Serum Levels of Trace Elements Before and After the Operation in Thyroid Cancer Patients

Baltacı

Dundar

Aksoy

et al. 2016

Biol Trace Elem Res

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The present study aims to examine the changes in the serum levels of trace elements before and after the operation in thyroid cancer patients. The study registered 50 individuals, of whom 25 were female and 25 were male. The patients were allocated to four groups: group 1: male thyroid cancer patients group (n = 15), group 2: female thyroid cancer patients group (n = 15), group 3: male control group (n = 10), group 4: female control group (n = 10). The subjects in groups 1 and 2 were the patients who were post-operatively diagnosed with a pathological malignancy in the thyroid tissue samples. Blood samples were collected from all subjects before the operation, immediately after the operation, and on the post-operative day 15. Additionally, thyroid tissue samples were taken from all subjects post-operatively. Some elements in the blood and tissue samples were determined using the atomic emission method. Zinc and selenium levels of groups 1 and 2 in the pre- and post-operative measurements were significantly lower than those in the control groups (p < 0.05), but were higher in the thyroid tissue (p < 0.05). Serum zinc and selenium levels measured in the subjects on the post-operative day 15 were similar to those measured in the controls. Our study show that changes in the serum and thyroid tissue levels of trace elements like zinc and selenium, which play a critical role in thyroid function, might be associated with the pathogenesis of thyroid cancer.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Changes in the Serum Levels of Trace Elements Before and After the Operation in Thyroid Cancer Patients

Baltacı

Dundar

Aksoy

et al. 2016

Biol Trace Elem Res

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“…It was speculated that the decreased TSH would have increased TRH secretion from the hypothalamus of these rats, but TRH secretion as well as expression of prepro-TRH mRNA in the hypothalamus were inhibited in normal and diabetic rats upon FSE feeding. Within the HPT axis, the hypophysiotropic TRH neurons are exclusively located in hypothalamic paraventricular nucleus (PVN) in rats [18]. These neurons together with TRH regulate the synthesis, release, and biological activities of TSH via TRH receptors present in the antero ▶Fig.…”

Section: Discussionmentioning

confidence: 99%

“…▶Fig. 3 RT-PCR of prepro-TRH mRNA expression following FSE feeding -medial and antero-lateral portions of pituitary [18]. Again, the production and secretion of TRH and TSH are regulated by circulatory levels of THs.…”

Section: Discussionmentioning

confidence: 99%

Fenugreek, A Potent Hypoglycaemic Herb Can Cause Central Hypothyroidism Via Leptin – A Threat To Diabetes Phytotherapy

Majumdar

Chakraborty

Mitra

et al. 2017

Exp Clin Endocrinol Diabetes

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Fenugreek (, a medicinal herb with potent antihyperglycaemic and hypoglycaemic effects, is used to treat diabetes. This study is aimed to explore the interaction of fenugreek seed extract (FSE) and HPT (hypothalamic-pituitary-thyroid) axis in context of leptin secretion which have important role in normal and type-1 diabetic subjects. FSE (confirmed to contain trigonelline, diosgenin, 4 hydroxyisoleucine) was gavaged (0.25 gm/kg body weight/day) to normal and alloxan-induced type-1 diabetic rats for 4 weeks. Expression of hypothalamic prepro-TRH (Thyrotropin releasing hormone) mRNA, serum levels of TRH, TSH (Thyroid stimulating hormone), fT, fT, insulin, leptin, glucose; thyroperoxidase activity and growth of thyroid gland, food intake, adiposity index were also studied FSE significantly down regulated prepro-TRH mRNA expression; decreased serum TRH, TSH, fT, fT levels, and regressed thyroid gland in FSE-fed normal and diabetic rats than those observed in normal diet-fed control and diabetic rats. FSE decreased (p<0.005-0.001) adiposity index and leptin secretion, increased food intake and body weight in all FSE-fed rats. FSE improved insulin secretion, decreased glucose level but impaired HPT axis in diabetic rats, indicating insulin-independent central hypothyroidism. Results suggested that the dominant signal to hypothalamus suppressing HPT axis is the fall in leptin level which i resulted from decreased adiposity index following FSE feeding. Fenugreek simultaneously having hypoglycaemic and hypothyroidal actions raises questions whether it can be safely used to treat diabetes and/or hyperthyroidism as was suggested by many workers.

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“…An epidemiological study in Germany in 1997 showed no correlation between zinc levels and thyroid function [135]. Zn deficiency can down regulate the activity of the TRH degrading enzyme in the hypothalamus and pituitary [136]. This results in increased levels of TSH and PRL.…”

Section: Minerals and Elements At The Metabolic Crossroads Between Thmentioning

confidence: 99%

Applying a systems approach to thyroid physiology: Looking at the whole with a mitochondrial perspective instead of judging single TSH values or why we should know more about mitochondria to understand metabolism

Moncayo¹,

Moncayo²

2017

BBA Clinical

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Classical thinking in endocrine physiology squeezes our diagnostic handling into a simple negative feedback mechanism with a controller and a controlled variable. In the case of the thyroid this is reduced to TSH and fT3 and fT4, respectively. The setting of this tight notion has no free space for any additions. In this paper we want to challenge this model of limited application by proposing a construct based on a systems approach departing from two basic considerations. In first place since the majority of cases of thyroid disease develop and appear during life it has to be considered as an acquired condition. In the second place, our experience with the reversibility of morphological changes makes the autoimmune theory inconsistent.While medical complexity can expand into the era of OMICS as well as into one where manipulations with the use of knock-outs and -ins are common in science, we have preferred to maintain a simple and practical approach. We will describe the interactions of iron, magnesium, zinc, selenium and coenzyme Q10 with the thyroid axis. The discourse will be then brought into the context of ovarian function, i.e. steroid hormone production. Finally the same elemental players will be presented in relation to the basic mitochondrial machinery that supports the endocrine.We propose that an intact mitochondrial function can guard the normal endocrine function of both the thyroid as well as of the ovarian axis. The basic elements required for this function appear to be magnesium and iron. In the case of the thyroid, magnesium-ATP acts in iodine uptake and the heme protein peroxidase in thyroid hormone synthesis. A similar biochemical process is found in steroid synthesis with cholesterol uptake being the initial energy-dependent step and later the heme protein ferredoxin 1 which is required for steroid synthesis. Magnesium plays a central role in determining the clinical picture associated with thyroid disease and is also involved in maintaining fertility. With the aid of 3D sonography patients needing selenium and/or coenzyme Q10 can be easily identified. By this we firmly believe that physicians should know more about basic biochemistry and the way it fits into mitochondrial function in order to understand metabolism. Contemplating only TSH is highly reductionistic.OutlineAuthor's profiles and motivation for this analysisThe philosophical alternatives in science and medicineReductionism vs. systems approach in clinical thyroid disease guidelinesThe entry into complexity: the involvement of the musculoskeletal systemIntegrating East and West: teachings from Chinese Medicine and from evidence based medicine (EBM)Can a mathematical model represent complexity in the daily thyroid practice?How effective is thyroxine treatment?Resolving the situation of residual symptoms in treated patients with thyroid diseaseImportance of iron, zinc and magnesium in relation to thyroid functionPutting together new concepts related to thyroid function for a systems approachExpanding our model into general aspects of ...

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Mediobasal hypothalamic and adenohypophyseal TRH‐degrading enzyme (PPII) is down‐regulated by zinc deficiency

Cited by 13 publications

References 81 publications

Changes in the Serum Levels of Trace Elements Before and After the Operation in Thyroid Cancer Patients

Changes in the Serum Levels of Trace Elements Before and After the Operation in Thyroid Cancer Patients

Fenugreek, A Potent Hypoglycaemic Herb Can Cause Central Hypothyroidism Via Leptin – A Threat To Diabetes Phytotherapy

Applying a systems approach to thyroid physiology: Looking at the whole with a mitochondrial perspective instead of judging single TSH values or why we should know more about mitochondria to understand metabolism

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