DOCSLIB.ORG

Perchlorate – Properties, Toxicity and Human Health Effects

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Perchlorate – Properties, Toxicity and Human Health Effects Rev Environ Health 2021; 36(2): 199–222 Review Article Przemysław Niziński*, Anna Błażewicz, Joanna Kończyk and Rajmund Michalski Perchlorate – properties, toxicity and human health effects: an updated review https://doi.org/10.1515/reveh-2020-0006 Introduction Received January 14, 2020; accepted July 28, 2020; published online September 4, 2020 Perchlorate has been identified as an environmental pollutant. Interest in perchlorate as potential substance Abstract: Interest in perchlorate as environmental affecting human health has increased since 1997, when pollutant has increased since 1997, when high concentra- large amounts of them have been detected in water sam- tions have been found in the waters of the Colorado River, ples from western states of the USA [1]. Sources of USA. Perchlorate is very persistent in nature and it is slowly perchlorate in the environment may include those related degraded. Although harmful effects of large doses of to human activity and natural formation. Naturally occur- perchlorate on thyroid function have been proven, the ring perchlorate were found in samples of Chilean nitrate, environmental effects are still unclear. The primary used on a large scale in agriculture as a fertilizer, probably objective of the present review is to collect prevailing data also formed during reactions occurring in the upper re- of perchlorate exposure and to discuss its impact on hu- gions of atmosphere. The sources related to human activity man health. The results show that more than 50% of should involve applications in military purposes, space reviewed works found significant associations of perchlo- exploration, fireworks and other industries [2]. In the past rate exposure and human health. This review consists of years perchlorate was used as a hyperthyroidism treating the following sections: general information of perchlorate agent, although it was withdrawn from medical usage due sources, its properties and determination methods, role to its grave adverse effects [3]. Perchlorate has been clas- and sources in human body including food and water sified as goitrogen (i.e., substance inhibiting iodine uptake intake, overview of the scientific literature on the research by thyroid cells), which disturbs the metabolism of thyroid on the effect of perchlorate on human health from 2010 to hormones and consequently can lead to serious health is- 2020. Finally, conclusions and recommendations on future sues [4, 5]. Many studies were conducted to examine the perchlorate studies concerning human exposure are effects of perchlorate on thyroid activity, while influence presented. on other tissues and organs is still unknown. There are few Keywords: endocrine disruptors; environmental hazard; papers describing the effect of perchlorate depending on goitrogens; perchlorate; risk assessment; thyroid. the route of administration other than oral (inhalation, transdermal) and on other tissues and systems of the hu- man body [6, 7]. Although the results of animal studies are available (mainly in rats) and significantly broaden the knowledge of perchlorate mode of action, their findings certainly require confirmation in humans [8]. Epidemio- *Corresponding author: Przemysław Niziński, Chair of Chemistry, logical research was mainly conducted in the US, partly Department of Analytical Chemistry, Medical University of Lublin, also in China, but so far in other regions of the world have + + Lublin, Poland, Phone: 48 534780270, Fax: 48 81 448 7181, been carried out on a very small scale [8, 9]. The review of E-mail: [email protected] perchlorate toxicity in humans was published in 2010 in Anna Błażewicz, Chair of Chemistry, Department of Analytical Chemistry, Medical University of Lublin, Lublin, Poland which the authors presented the outcomes of population Joanna Kończyk, Institute of Chemistry, Health and Food Sciences, exposure studies, multiple regression analyses of sodium- Faculty of Mathematics and Natural Sciences, Jan Dlugosz University iodine symporter (NIS) inhibitors in urine and thyroid in Czestochowa, Czestochowa, Poland hormone concentration. Some of the occupational studies Institute of Chemistry, Health and Food Sciences, Rajmund Michalski, were included and the impact of gestational perchlorate Faculty of Mathematics and Natural Sciences, Jan Dlugosz University in Czestochowa, Czestochowa, Poland; Institute of Environmental exposure of newborn thyroid function were investigated. Engineering, Polish Academy of Sciences, Zabrze, Poland Conclusion of the aforementioned review indicates that Open Access. © 2020 Przemysław Niziński et al., published by De Gruyter. This work is licensed under the Creative Commons Attribution 4.0 International License. 200 Niziński et al.: Perchlorate: an updated review there is no strong evidence between abnormal thyroid inherently incomplete and consequently far from being function and environmental perchlorate exposure, but actual. It is estimated that the annual global production of there are some weaknesses of this study. Reviewed works perchlorate is about several hundred thousand tons and were mainly conducted in the US and very few were from the largest production plants are placed in the USA, different geographical regions, such as East Asia or France, Germany, Italy, China and Brazil [16–17]. Europe. The investigated outcomes were focused directly Anthropogenic sources include the import and use of on thyroid hormones or TSH levels and ignored many other Chilean nitrate as a fertilizer exploited from deposits in the serious health effects [10]. In the past decade many of new Atacama desert in Chile. The fertilizer produced on the facts about perchlorate toxicity, involving non-thyroidal basis of Chilean nitrate contains approximately 98% outcomes were acknowledged. A new mechanisms of NaNO3 and, according to various studies, from 0.05 to − perchlorate impact on NIS were proposed [11], so a novel 0.4% ClO4 [18]. In the 1830–1980 period, the estimated approach on environmental perchlorate toxicity was taken volume of imports of Chilean saltpeter ore to the USA and in our review. The review focuses on the period of 2010– Europe amounted to approximately 23 million tons in 2020 to investigate into the most recent directions of terms of nitrogen, with the highest value being reported in perchlorate studies. 1930s [19]. In US commercial production of sodium nitrate In this review we present the most actual knowledge of began in 1915 and in the following years domestic pro- perchlorate chemistry, its environmental occurrence and duction increased its share in total US nitrate consumption. human toxicity. The new data about perchlorate occur- In 1994 over 11 million tons of sodium nitrate were used in rence and health effect still reveals and there is essential US agriculture and only approximately 30,000 tons were need to re-evaluate periodically the state of knowledge on from imported Chilean nitrate [2]. According to United these compounds [12]. The main purpose of this work is to Nations Trade Statistics Branch the volume of sodium ni- discuss findings of the human population studies from the trate import from Chile was about 19,000 tons in 2018 [20]. peer-reviewed literature published in last 10 years which A material evidence of increasing man-made perchlorate assessed potential risk of exposure and health effects. We contamination has been disclosed in shallow ice core in − also present the chemistry and some routes of exposure in Thienshan, East Asia, where concentration of ClO4 was order to facilitate the environmental perchlorate pollution. still increasing during 1980s’ to 2004 [21]. This review seeks to indicate the gaps of knowledge on perchlorate and attempts to outline new directions of prospective perchlorate studies. Natural The largest known perchlorate reservoir in the world are Sources in the environment the aforementioned Chilean saltpeter deposits. The presence of natural perchlorate has also been demon- Anthropogenic strated in snow samples from Arctic, waters of the Great Lakes (USA and Canada), soil samples from Death Valley Perchlorate was described for the first time by Count Frie- (USA)andDryValley(Antarctica)[1,22–25]. In 2015, the drich von Stadion in the work “Von den Verbindungen des results of determination of perchlorate content in surface Chlorine mit dem Sauerstoff” in 1816 [13]. Significant in- and underground waters as well as soil samples from crease in worldwide production of perchlorate was semi-arid areas and deserts (Atacama Desert in Chile, observed during World War II. In 1940 global production of Mojave Desert in the USA, deserts in western regions of − −1 ammonium perchlorate was about 2,000 tons per year, Africa), showed the presence of ClO4 in range from 10 then in 1945 it was approximately 20,000 tons [14]. In this to 106 μg/kg [26]. The mechanism of formation of period perchlorate were mainly used for the production of perchlorate in nature is not fully understood. Several explosives for war industry. After 1945, the production of paths of a possible perchlorate natural formation have perchlorate continued to grow especially for military ap- been proposed [2, 26–31], mainly in photochemical pro- plications, as their interesting properties were discovered cesses, with the participation of chloride ions and ozone as a valuable component of rocket fuel [15]. In conjunction in the troposphere and stratosphere [32]. The theory with the current use of perchlorate in military installations, indicating the possibility of perchlorate
Load more

Recommended publications
  • Assessment of Iodine Deficiency Disorders and Monitoring Their Elimination
    Assessment of iodine deficiency disorders and monitoring their elimination A GUIDE FOR PROGRAMME MANAGERS Third edition Assessment of iodine deficiency disorders and monitoring their elimination A GUIDE FOR PROGRAMME MANAGERS Third edition WHO Library Cataloguing-in-Publication Data Assessment of iodine deficiency disorders and monitoring their elimination : a guide for programme managers. – 3rd ed. 1.Iodine – deficiency. 2.Nutrition disorders – prevention and control. 3.Sodium chloride, Dietary – therapeutic use. 4.Nutrition assessment. 5.Nutrition policy – standards. 6.Guidelines. I.World Health Organization. ISBN 978 92 4 159582 7 (NLM classification: WK 250) This report contains the collective views of an international group of experts, and does not necessarily represent the decisions or the stated policy of the World Health Organization. © World Health Organization 2007 All rights reserved. Publications of the World Health Organization can be obtained from WHO Press, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland (tel.: +41 22 791 3264; fax: +41 22 791 4857; e-mail: [email protected]). Requests for permission to reproduce or translate WHO publications – whether for sale or for noncom- mercial distribution – should be addressed to WHO Press, at the above address (fax: +41 22 791 4806; e-mail: [email protected]). The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organi- zation concerning the legal status of any country, territory, city or area or of its authori- ties, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement.
    [Show full text]
  • Early Effects of Iodine Deficiency on Radial Glial Cells of the Hippocampus of the Rat Fetus
    Early effects of iodine deficiency on radial glial cells of the hippocampus of the rat fetus. A model of neurological cretinism. J R Martínez-Galán, … , G Morreale de Escobar, A Ruiz-Marcos J Clin Invest. 1997;99(11):2701-2709. https://doi.org/10.1172/JCI119459. Research Article The most severe brain damage associated with thyroid dysfunction during development is observed in neurological cretins from areas with marked iodine deficiency. The damage is irreversible by birth and related to maternal hypothyroxinemia before mid gestation. However, direct evidence of this etiopathogenic mechanism is lacking. Rats were fed diets with a very low iodine content (LID), or LID supplemented with KI. Other rats were fed the breeding diet with a normal iodine content plus a goitrogen, methimazole (MMI). The concentrations of -thyroxine (T4) and 3,5,3'triiodo-- thyronine (T3) were determined in the brain of 21-d-old fetuses. The proportion of radial glial cell fibers expressing nestin and glial fibrillary acidic protein was determined in the CA1 region of the hippocampus. T4 and T3 were decreased in the brain of the LID and MMI fetuses, as compared to their respective controls. The number of immature glial cell fibers, expressing nestin, was not affected, but the proportion of mature glial cell fibers, expressing glial fibrillary acidic protein, was significantly decreased by both LID and MMI treatment of the dams. These results show impaired maturation of cells involved in neuronal migration in the hippocampus, a region known to be affected in cretinism, at a stage of development equivalent to mid gestation in humans.
    [Show full text]
  • Evolution of Hypothyroidism in Familialgoitre Due to Deiodinase
    Postgraduate Medical Journal (1986) 62, 477-480 Postgrad Med J: first published as 10.1136/pgmj.62.728.477 on 1 June 1986. Downloaded from Evolution ofhypothyroidism in familial goitre due to deiodinase deficiency: report of a family and review ofthe literature Harry J. Hirsch, Shmuel Shilo and Irving M. Spitz Department ofEndocrinology andMetabolism, Shaare Zedek Hospital and Hadassah Hebrew University Medical School, Jerusalem, Israel and The Centerfor Biomedical Research, The Population Council, New York, N. Y., USA Summary: We studied two sisters who developed large non-toxic goitres in adolescence. Deiodinase deficiency was diagnosed by a rapid thyroid uptake ofradioactive iodine (RAI) at 2 hours associated with a marked fail in thyroidal 131I by 24 hours. Serial RAI scans in the second patient documented evolution of the iodine-deficient state. Conservation of intra-thyroidal iodine stores was maintained by avid iodine uptake and failure to release organified 1311. With progressive loss of inorganic iodine, hypothyroidism developed, associated with a rise in serum TSH which further exacerbated the loss of iodine. Treatment with L-thyroxine resulted in an improvement ofthyroid function, but normalization was achieved only after small doses of Lugol's iodine were administered. These studies illustrate the variable nature and late onset ofan inborn error ofthyroid metabolism. This family supports an autosomal recessive mode of inheritance for deiodinase deficiency. We have documented progression from a euthyroid to hypothyroid state resulting from decompensation of iodine conservation mechanisms. copyright. Introduction We have studied two sisters who developed large non- The mean ± s.d. basal TSH levels in 14 female controls toxic goitres in adolescence.
    [Show full text]
  • Role of Thyroid Hormones in the Development of Gonadal Sex, External Morphology and Intestinal System of Zebrafish (Danio Rerio)
    ROLE OF THYROID HORMONES IN THE DEVELOPMENT OF GONADAL SEX, EXTERNAL MORPHOLOGY AND INTESTINAL SYSTEM OF ZEBRAFISH (DANIO RERIO) by PRAKASH SHARMA, B.S., M.S. A Dissertation In BIOLOGY Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Approved Dr. Reynaldo Patiño Chair of Committee Dr. Gregory D. Mayer Dr. James Carr Dr. Lauren Gollahon Dr. Nathan Collie Dr. Richard Strauss Dominick Joseph Casadonte Dean of the Graduate School December, 2012 Copyright 2012, Prakash Sharma Texas Tech University, Prakash Sharma, December 2012 ACKNOWLEDGMENTS First, I am privileged to thank Dr. Reynaldo Patiño, my major advisor and mentor for his guidance and encouragement which have been of immense support. He has been there to help and extend his guidance, anywhere, anytime, even at wee hours despite his busy schedule. Through him, I have not only picked up skills and a sense of responsibility, but also a whole new level of dedication. It is definitely a lifetime opportunity to have worked with an efficient and resourceful scientist like him. I am honored to thank my Committee Members for their enthusiasm to scrutinize my research. Thanks to Drs. Gregory D. Mayer, James Carr, Lauren Gollahon, Nathan Collie, and Richard Strauss. Their suggestions, ideas and information on the analysis of my study were of great significance. I could not have asked for a better cooperating team. Also, a million thanks to Dr. Gregory D. Mayer for supporting and guiding me immensely throughout my research program and for allowing me the opportunity to work in his lab.
    [Show full text]
  • Iodine Deficiency
    Holistic Medicine for the 21st Century David Brownstein, M.D. Center for Holistic Medicine 5821 W. Maple Rd. Ste. 192 West Bloomfield, MI 48322 248.851.1600 www.drbrownstein.com Leo Tolstoy “I know that most men, including those at ease with problems of the greatest complexity, can seldom accept even the simplest and most obvious truth if it would oblige them to admit to the falsity of conclusions they have delighted in explaining to their colleagues.” Medical Iodophobics Claim Iodine Causes…. • AIT • Hypothyroidism (IIH) • Hyperthyroidism • Brain Melting • Locusts, frogs, plague, darkness, and more • See Passover “Don’t Take Iodine!” Medical Iodophobia “Medical iodophobia is the unwarranted fear of using and recommending inorganic, non- radioactive iodine/iodide within the range known from the collective experience of three generations of clinicians to be the safest and most effective amounts for treating symptoms and signs of iodine/iodide deficiency (12.5- 50mg/day).” Dr. G. Abraham, 2004 Thyroid Nodules and Iodine • Both benign and malignant thyroid nodules have significantly less iodine than normal thyroid tissue Benign thyroid nodules contain 56% of the iodine content as compared to normal thyroid tissue Malignant thyroid nodules contain 3% of the iodine content as compared to normal thyroid tissue Analyst. March 1995, Vol. 120 Periodic Table History of Iodine • Discovered in 1811 • First used by Dr. William Prout (1816) in London for a patient with goiter J. Royal Soc. Of Med. 2011;104:15-18 History of Iodine • Birth of western
    [Show full text]
  • Incidence of Amiodarone-Induced
    Med Pregl 2011; LXIV (11-12): 533-538. Novi Sad: novembar-decembar. 533 Helath Center Zaječar Originalni naučni rad Nuclear Medicine Services1 Original study Internal Medicine Services2 UDK 616.441-008:615.222.06 DOI: 10.2298/MPNS1112533A INCIDENCE OF AMIODARONE-INDUCED THYROID DYSFUNCTION AND PREDICTIVE FACTORS FOR THEIR OCCURRENCE INCIDENCIJA AMIODARONOM INDUKOVANIH TIROIDNIH DIFUNCKIJA I PREDIKTIVNI FAKTORI ZA NJIHOV NASTANAK Željka ALEKSIĆ1 and Aleksandar ALEKSIĆ2 Summary – Amiodarone treatment is associated with the occurrence of thyroid dysfunction. The aim was to determine the incidence of amiodarone-induced thyroid dysfunctions and the influence of gender, age, treatment duration, goiter, thyroid antibodies, thyroid echo- genicity and family history on their appearance. Of 248 consecutive patients, 144 males and 104 females, referred to thyroid status screen- ing, 16% were with clinical dysfunction, 21% with sub-clinical dysfunction and 63% were euthyroid. The presence of goiter and thyroid peroxidase antibodies were the significant individual predictive factors for the occurrence of clinical dysfunction, and in the multivariate regression model, the presence of goiter was a significant predictive factor with the prognostic value of 80%. For sub-clinical dysfunction, the significant individual predictive factors were female gender and the presence of goiter, as well as in the multivariate regression model, with the prognostic value of 74.5% for female gender and 77.5 % for the presence of goiter. It is necessary to check the thyroid status both before and during amiodarone treatment. Administration of other anti-arrhythmic drugs and/or more frequent check-ups of the thyroid sta- tus should be taken into consideration in patients at higher risk, i.e.
    [Show full text]
  • Getting Hyper Over Thyroid Function: an Approach to Thyroid Disorders in Childhood
    GETTING HYPER OVER THYROID FUNCTION: AN APPROACH TO THYROID DISORDERS IN CHILDHOOD SARAH LAWRENCE, MD, FRCPC PEDIATRIC ENDOCRINOLOGY DISCLOSURE • Nothing to disclose 2 Objectives Provide cost Manage Formulate a effective neonatal thyroid management evaluation and disorders plan for the treatment including a patient with for patients with positive hyperthyroidism goiter newborn screen and/or and infants of hypothyroidism mothers with Graves’ disease 3 How common are thyroid disorders in children? • NHANES report: 2% of 12 −19 yrs olds in US have subclinical hypothyroidism (defined as TSH >4.5 mU/L, normal T4) Hollowell JG, et al, JCEM 2002 • 3-4% of school aged children/youth will have some sort of thyroid condition on evaluation —Goiter is most common —1-2% autoimmune hypothyroidism (4:1 female preponderance) —Graves 0.1-3 cases per 100,000 with geographic variation • 1/10,000 in US • 1/100,000 in the UK and Ireland Bauer, JAMA Pediatrics 2015 4 CLINICAL EVALUATION 5 History and Physical • Family history • Constitutional symptoms are common to all age groups • Unique to the pediatric age group, is impact on growth 6 Hypothyroidism Hypothyroidism post treatment Thyroid exam Normal Volume: Child: 1 ml birth 6-7 ml age 14 Clinically: Goiter: Each lobe is > size of distal phalanx of child’s thumb (1960 WHO) 9 Patient education Pituitary TSH X Thyroid FT4 Growth Metabolism Reference Intervals 11 Old vs New RI at CHEO *except neonatal fT4 Medication effects on TFTs 1. Glucocorticoids: low TSH, low T3 and N/slightly low free T4 2. Dopamine (prolonged use): Low TSH, low free T4 and free T3 3.
    [Show full text]
  • Medical Therapy of Patients Contaminated with Radioactive Cesium Or Iodine
    Roskilde University Medical Therapy of Patients Contaminated with Radioactive Cesium or Iodine Aaseth, Jan; Nurchi, Valeria Marina; Andersen, Ole Published in: Biomolecules DOI: 10.3390/biom9120856 Publication date: 2019 Document Version Publisher's PDF, also known as Version of record Citation for published version (APA): Aaseth, J., Nurchi, V. M., & Andersen, O. (2019). Medical Therapy of Patients Contaminated with Radioactive Cesium or Iodine. Biomolecules, 9(12), [856]. https://doi.org/10.3390/biom9120856 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain. • You may freely distribute the URL identifying the publication in the public portal. Take down policy If you believe that this document breaches copyright please contact [email protected] providing details, and we will remove access to the work immediately and investigate your claim. Download date: 30. Sep. 2021 biomolecules Review Medical Therapy of Patients Contaminated with Radioactive Cesium or Iodine Jan Aaseth 1,2,* , Valeria Marina Nurchi 3 and Ole Andersen 4 1 Research Department, Innlandet Hospital Trust,
    [Show full text]
  • 9. References
    IODINE 325 9. REFERENCES Abbott A, Barker S. 1996. Chernobyl damage 'underestimated'. Nature 380:658. Abdel-Nabi H, Ortman JA. 1983. Radiobiological effects of 131I and 125I on the DNA of the rat thyroid: I. Comparative study with emphasis on the post radiation hypothyroidism occurrence. Radiat Res 93:525-533. *Abdullah ME, Said SA. 1981. Release and organ distribution of 125I from povidone-iodine under the influence of certain additives. Arzneim Forsch 31(1):59-61. Abel MS, Blume AJ, Garrett KM. 1989. Differential effects of iodide and chloride on allosteric interactions of the GABAA receptor. J Neurochem 53:940-945. *Aboul-Khair SA, Buchanan TJ, Crooks J, et al. 1966. Structural and functional development of the human foetal thyroid. Clin Sci 31:415-424. Aboul-Khair SA, Crooks J, Turnbull AC, et al. 1964. The physiological changes in thyroid function during pregnancy. Clin Sci 27:195-207. Absil AC, Buxeraud J, Raby C. 1984. [Charge-transfer complexation of chlorpromazine in the presence of iodine; thyroid side effect of this molecule.] Can J Chem 62(9):1807-1811. (French) ACGIH. 1992. Iodine. In: Documentation of the threshold limit values and biological exposure indices. Sixth Edition. Volume II. American Conference of Governmental Industrial Hygienists Inc. Cincinnati, OH. *ACGIH. 2000. Threshold limit values for chemical substances and physical agents and biological exposure indices. American Conference of Governmental Industrial Hygienists Inc. Cincinnati, OH. Adamson AS, Gardham JRC. 1991. Post 131I carcinoma of the thyroid. Postgrad Med J 67:289-290. *Ader AW, Paul TL, Reinhardt W, et al. 1988. Effect of mouth rinsing with two polyvinylpyrrolidone­ iodine mixtures on iodine absorption and thyroid function.
    [Show full text]
  • Iodine, Thiocyanate and the Thyroid Chandra Amar K* Department of Physiology, University of Calcutta, University College of Science & Technology, Kolkata, India
    mac har olo P gy Chandra Amar, Biochem Pharmacol (Los Angel) 2015, 4:3 : & O y r p t e s DOI: 10.4172/2167-0501.1000171 i n A m c e c h e c s Open Access o i s Biochemistry & Pharmacology: B ISSN: 2167-0501 Research Article Open Access Iodine, Thiocyanate and the Thyroid Chandra Amar K* Department of Physiology, University of Calcutta, University College of Science & Technology, Kolkata, India Introduction or indirectly by altering the regulatory mechanism of thyroid gland. The uptake and utilization of iodine, by the thyroid gland is impaired Thiocyanate is a ubiquitous metabolite in man and animals by the pseudo halide thiocyanate (SCN-). Thiocyanate is formed from consuming plants containing cyanogenic glycosides and thioglycosides cyanogenic substances. It is metabolized in thyroid gland. The role of (glucionates) while iodine is present in the earth crust since its origin thiocyanate ion in the homeostasis of thyroid is a provocative issue and is an essential constituent of thyroid hormone requires in trace where IDD persists inspite of adequate iodine intake and consumption amount. Iodine is essential for thyroid hormone synthesis while of cyanogenic plant food is relatively high. The article reviews the thiocyanate prevents the synthesis of thyroid hormone. As a result physiology of the thyroid gland in relation to iodine and thiocyanate the physiological rather functional status of thyroid is very much metabolism. dependent on the balance between these ions because of their similar ionic volume and charges and competition at different steps in thyroid Bioavailability of Iodine and Thiocyanate hormone biosynthesis. Both iodine and thiocyanate enter in the body / thyroid gland through food and water.
    [Show full text]
  • Environmental Factors Affecting Thyroid-Stimulating Hormone and Thyroid Hormone Levels
    International Journal of Molecular Sciences Review Environmental Factors Affecting Thyroid-Stimulating Hormone and Thyroid Hormone Levels Mirjana Babi´cLeko , Ivana Gunjaˇca , Nikolina Plei´c and Tatijana Zemunik * Department of Medical Biology, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia; [email protected] (M.B.L.); [email protected] (I.G.); [email protected] (N.P.) * Correspondence: [email protected]; Tel.: +385-21-557-888 Abstract: Thyroid hormones are necessary for the normal functioning of physiological systems. Therefore, knowledge of any factor (whether genetic, environmental or intrinsic) that alters the levels of thyroid-stimulating hormone (TSH) and thyroid hormones is crucial. Genetic factors contribute up to 65% of interindividual variations in TSH and thyroid hormone levels, but many environmental factors can also affect thyroid function. This review discusses studies that have analyzed the impact of environmental factors on TSH and thyroid hormone levels in healthy adults. We included lifestyle factors (smoking, alcohol consumption, diet and exercise) and pollutants (chemicals and heavy metals). Many inconsistencies in the results have been observed between studies, making it difficult to draw a general conclusion about how a particular environmental factor influences TSH and thyroid hormone levels. However, lifestyle factors that showed the clearest association with TSH and thyroid hormones were smoking, body mass index (BMI) and iodine (micronutrient taken from the diet). Smoking mainly led to a decrease in TSH levels and an increase in triiodothyronine (T3) and thyroxine (T4) levels, while BMI levels were positively correlated with TSH and free T3 levels. Excess iodine led to an increase in TSH levels and a decrease in thyroid hormone levels.
    [Show full text]
  • Variable Effects of Goitrogens in Inducing Precocious Metamorphosis in Sea Lampreys (Petromyzon Marinus)
    290 R.G. JOURNALMANZON ET OF AL. EXPERIMENTAL ZOOLOGY 289:290–303 (2001) Variable Effects of Goitrogens in Inducing Precocious Metamorphosis in Sea Lampreys (Petromyzon marinus) RICHARD G. MANZON, JOHN A. HOLMES, AND JOHN H. YOUSON* Department of Zoology and Division of Life Sciences, University of Toronto at Scarborough, Toronto, Ontario, M1C 1A4 Canada ABSTRACT The ability of different goitrogens (anti-thyroid agents) to induce precocious meta- morphosis in larval sea lampreys (Petromyzon marinus) was assessed in four separate experi- ments. Two of these goitrogens (propylthiouracil [PTU] and methimazole [MMI]) are inhibitors of thyroid peroxidase-catalyzed iodination, and three (potassium perchlorate [KClO4], potassium thio- cyanate [KSCN], and sodium perchlorate [NaClO4]) are anionic competitors of iodide uptake. Be- cause, theoretically, all of these goitrogens prevent thyroid hormone (TH) synthesis, we also measured their influence on serum concentrations of thyroxine and triiodothyronine. All goitro- gens except PTU significantly lowered serum TH concentrations and induced metamorphosis in some larvae. The incidence of metamorphosis appeared to be correlated with these lowered TH concentrations in that KClO4, NaClO4, and MMI treatments resulted in the lowest serum TH concentrations and the highest incidence of metamorphosis in sea lampreys. Moreover, fewer lar- vae metamorphosed in the KSCN and low-KClO4 treatment groups and their serum TH concen- trations tended to be greater than the values in the aforementioned groups. MMI treatment at the concentrations used (0.087 and 0.87 mM) was toxic to 55% of the exposed sea lampreys within 6 weeks. The potassium ion administered as KCl did not alter serum TH concentrations or induce metamorphosis.
    [Show full text]