DOCSLIB.ORG

Estrogen Status Alters Tissue Distribution and Metabolism Of

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

THE EFFECT OF ESTROGEN STATUS ON SELENIUM METABOLISM IN FEMALE RATS DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Xiaodong Zhou, M.S. ***** The Ohio State University 2007 Dissertation Committee: Approved by Dr. Anne M. Smith, Advisor Dr. Mark L. Failla Dr. Steven K. Clinton Advisor Dr. Charles L. Brooks The Ohio State University Nutrition Graduate Program ABSTRACT An association between male and female sex hormones and selenium (Se) status has been reported in animals and humans. These relationships may be important in the regulation of selenium metabolism and relative to the possible use of selenium as an adjunct for treatment of hormone-related diseases such as breast cancer. Insights about impact of estrogen on distribution and metabolism of selenium in multiple tissues are limited. The purpose of the first part of this study was to examine the effect of estrogen status on the absorption, tissue distribution and metabolism of orally administered 75Se-selenite. Female Sprague Dawley (SD) rats were bilaterally ovariectomized and implanted with either a placebo pellet (OVX, n=16) or pellet with estradiol (OVX+E2, n=16) at 7 weeks of age. At 12 weeks of age, 60 µCi (43 ng total) of 75Se as selenite was orally administered to each rat. Blood and organs were collected 1, 3, 6, and 24h after dosing (4 rats/group at each time). Although apparent absorption of 75Se was independent of estrogen status, hormone associated differences of 75Se levels (P<0.05) were noted in plasma, RBC, liver, heart, kidney, spleen, brain, and thymus at certain times. For ii example, total 75Se in liver was greater in OVX than in OVX+E2 rats after 1 hour (13.1% vs.3.9% of total dose). However, OVX+E2 group had greater 75Se in liver than OVX group (18.0% vs. 10.9%) after 6h. The relative distribution of 75Se between cytosol and membrane fractions in organs was independent of estrogen status. Also the relative distribution of 75Se among the selenoproteins in cytosol of the organs was not influenced by estrogen status. However, plasma selenoprotein P (SelP) in OVX+E2 group contained a greater percentage of administered 75Se at 3, 6 and 24h after gavage compared to OVX group (P<0.05). 75Se in plasma glutathione peroxidase (GPx) also was greater in OVX+E2 compared to OVX group at 24 h (P<0.05). The second aim was to investigate the effect of estrogen status on selenium status in blood and tissues and explore whether hepatic levels of SelP mRNA and GPx1 mRNA were affected by estrogen status. SD female rats (7 weeks of age) were bilaterally ovariectomized and implanted with either a placebo pellet (OVX, n=6) or pellet with estradiol (OVX+E2, n=6). A second set of SD female rats also were sham-operated and implanted with a placebo pellet (Sham, n=24; 6 rats in each 4-day estrous cycle). Blood and tissues were collected at 12 weeks of age. Estrogen significantly increased selenium status as measured by selenium concentration and GPx activity in plasma, liver, and brain. Selenium concentration in RBC was also increased by estrogen treatment. Selenium status in kidney and heart was independent of estrogen treatment. Real-time RT-PCR iii analysis demonstrated that both hepatic SelP and GPx1 mRNA were significantly increased by estrogen treatment (P<0.05). In conclusion, these results suggest that estrogen status affects distribution of ingested selenium in tissue- and time-dependent manners. Expression of hepatic SelP and GPx was regulated by estrogen at both mRNA and protein levels. As SelP has been shown to function as a selenium transporter, estrogen regulation of SelP may play an important role in whole body metabolism of selenium. iv Dedicated to my wife, Wenyi v ACKNOWLEDGMENTS During my Ph.D. journey at The Ohio State University, there has been so much support and encouragement without which this dissertation could not have been possible. I would like to express my sincere gratitude to my advisor, Dr. Anne Smith. Her intellectual ideas, guidance, and research expertise was a tremendous help throughout my dissertation research. Especially, I am grateful for her patience and encouragement that helped me through each difficulty during my study. I wish to thank Dr. Mark Failla. His insightful advice and continuous intellectual challenge have been key in facilitating my growth as a researcher. I sincerely appreciate my committee members, Dr. Steven Clinton and Dr. Charles Brooks for sharing their time and research expertise with me over the years, and for their valuable advice on my dissertation research. I wish to thank Dr. Zhontang Yu and Dr. Mark Morrison for the incredible opportunity to work in the molecular microbiology lab to conduct the real-time RT-PCR analysis. Thanks to Dr. Jing Chen for training me on the molecular biology techniques, to Dr. Valerie Bergdall for the training on estrus cycle determination in rats and valuable advice on animal handling, to Dr. Michael Darby for helping me set up the gamma vi counter, to Dr. John Bruno for his kindness to let me use his microscope and dissection equipment at Townshend Hall, to Jodi Griffith for her help on animal tissue collection, to Dr. Maureen Geraghty for her encouragement and friendship, and to Jeanne McGuire for the help on radioactive materials handling. My special gratitude goes to Dr. Kristina Hill, and Dr. Raymond Burk at the Vanderbilt University, for their assistance on plasma selenoprotein P measurement, and insights on selenium research over the years. I am grateful to the financial support from OARDC for my dissertation research. I wish to express my appreciation to the Department of Chemistry, who granted me the highly competitive teaching assistantship during my final stage of the Ph.D. study. Lastly, I would like to especially thank my wife, Wenyi and my parents, for their love, faith, and expectation. I would not have reached this point without their consistent support. vii VITA January 21, 1971……………………Born Mianyang, Sichuan Province, China 1995…………………………………Bachelor of Medicine, West China University of Medical Sciences, China 1998…………………………………M.S., Human Nutrition, West China University of Medical Sciences, China 1998-2001…………………………..Clinical Dietitian and lecturer, First University Hospital, West China University of Medical Sciences, China 2001-2006…………………………..Graduate Research and Teaching Associate, Department of Human Nutrition, The Ohio State University 2006-present…………………………Graduate Teaching Associate, Department of Chemistry, The Ohio State University PUBLICATIONS 1． Zhou, X., Smith, A.M., and Failla, M.L. Estrogen Status Alters Tissue Distribution of Oral Dose of 75Se-Selenite and Liver mRNA Levels of SelP and GPx. FASEB J 2007; 21 (5): A717 (Abstract). 2． Zhou, X., Huang, C., Hong, J.,Yao, S., and Zhang, J. A Nested case-control Study on Riboflavin Levels in Blood and Urine and the Risk of Lung Cancer. Journal of Hygiene Research 2003; 32 (6):597-598, 601. viii 3． Mao, S., Li, J., Zhou, X., Yuan, H., and Yang Z. Enternal Nutrition Support for the Postoperative Patients with Larynx Tumor. Chinese Journal of Clinical Nutrition 2002; 10 (2): 93-95. 4． Zhang, J., Zhou, X., Huang, C., Yao, S., Chang, S., Qiao, Y., and Taylor, P. Reproducibility and Validity of a Food Frequency Questionnaire among Male Miners. Modern Preventive Medicine 1999; 26 (2): 198-199, 226. 5． Zhou, X., Zhang. J., Huang. C., Yao. S., Taylor, P., and Qiao, Y.. A Case-Control Study of Vitamins and Lung Cancer Risk. Acta Nutrimenta Sinica 1999; 21 (4): 470-473. 6． Zhou, X., Huang. C., Yu. Q., and Lin. Y. The Effects of Malva Crispa Powder on Immune Function in Normal Mice. Modern Preventive Medicine 1998; 25 (3): 311-313. FIELDS OF STUDY Major Field: The Ohio State University Nutrition Program ix TABLE OF CONTENTS Page Abstract…………………………………………………………………………………....ii Dedication………………………………………………………………………………....v Acknowledgments.. ..…………………………………………………………………….vi Vita……………………………………………………………………………………...viii Table of contents………………………………………………………………………….x List of tables…………………………………………………………………………….xiii List of figures……………………………………………………………………………xiv Chapters: 1 Introduction……………………………………………………………………….…1 2 Literature review…………………………………………………………………......8 2.1 General information of selenium…...……………………………………………8 2.2 Selenoproteins……………………………………………………………………9 2.2.1 Brief introduction of known selenoproteins…………………………….9 2.2.2 Glutathione peroxidase………………………………………………...12 2.2.3 Selenoprotein P………………………………………………………...19 2.3 Selenium metabolism…………………………………………………………...32 2.3.1 Absorption……………………………………………………………...33 2.3.2 Transport……………………………………………………………….37 2.3.3 Tissue distribution……………………………………………………...38 2.3.4 Metabolic pathways……………………………………………………41 2.3.5 Selenium incorporation into selenoproteins……………………………44 2.3.6 Excretion……………………………………………………………….46 2.3.7 Selenium metabolism models………………………………………….52 2.4 Requirements of selenium………………………………………………………59 2.5 Selenium deficiency…………………………………………………………….62 2.5.1 Keshan disease…………………………………………………………62 2.5.2 Kaschin-Beck disease………………………………………………….65 2.5.3 Selenium deficiency in New Zealand and Finland…………………….65 2.6 Selenium toxicity……………………………………………………………….66 x 2.7 Selenium and hormone-related cancers………………………………………...68 2.7.1 Selenium and breast cancer…………………………………………….69 2.7.2 Selenium and prostate cancer……………………………………….….73 2.8 Estrogen receptors in estrogen action…………………………………………..80 2.8.1 Estrogens……………………………………………………………….80 2.8.2 Estrogen receptor………………………………………………………82
Recommended publications
  • Different Responsiveness to Progesterone for Induction of Pseudopregnancy Between the First and the Third Estrous Cycle After Vaginal Opening in Rats

    Different Responsiveness to Progesterone for Induction of Pseudopregnancy Between the First and the Third Estrous Cycle After Vaginal Opening in Rats

    September 1990 Jpn J Anim Reprod Vol 36 (3) Different Responsiveness to Progesterone for Induction of Pseudopregnancy between the First and the Third Estrous Cycle after Vaginal Opening in Rats Hiroshi TOMOGANE and Akira YOKOYAMA Departmentof Animal Science,School of Agriculture,Nagoya University,Chikusa, Nagoya 464-01, Japan (Accepted for publication May 16, 1990) Summary. Effects of progesterone on the function of corpus luteum in estrous cycle were compared between the first and the third estrous cycle after vaginal opening in rats. When 2.5 mg/100 g body weight (B.W.) progesterone was administered between 07:00 and 08:00 hr on the day of estrus or on day 1 of diestrus to rats showing the first estrous cycle, the diestrous period was persisted more than 9 days in 95% of animals. In the diestrous period, plasma prolactin (PRL) level showed daily changes and corpora lutea became functional. The luteal function was enhanced by the deciduoma formed after uterine traumatization on day 3 of diestrus. However, in rats showing the third estrous cycle, 7.5 mg/100 g B.W. progesterone was required to induce similar response to those obtained in the first estrous cycle. Also, no functional corpora lutea and no daily change in PRL secretion were observed in rats injected with progesterone on day 1 of diestrus in the third estrous cycle. These results indicate that progesterone acts more effectively for induction of pseudopregnant diestrus in the first estrous cycle than in the third estrous cycle. KEYWORDS: PSEUDOPREGNANCY, PROGESTERONE, PROLACTIN, PUBERTAL RAT Jpn J Anim Reprod 36, 176-183, 1990 In adult cyclic rats, the corpus luteum has If progesterone administration is limited not become functional, unless the cervical to the early morning of day of estrus in adult stimulus is given.
  • Research Article Combined Treatment with Myo-Inositol and Selenium Ensures Euthyroidism in Subclinical Hypothyroidism Patients with Autoimmune Thyroiditis

    Research Article Combined Treatment with Myo-Inositol and Selenium Ensures Euthyroidism in Subclinical Hypothyroidism Patients with Autoimmune Thyroiditis

    Hindawi Publishing Corporation Journal of Thyroid Research Volume 2013, Article ID 424163, 5 pages http://dx.doi.org/10.1155/2013/424163 Research Article Combined Treatment with Myo-Inositol and Selenium Ensures Euthyroidism in Subclinical Hypothyroidism Patients with Autoimmune Thyroiditis Maurizio Nordio1 and Raffaella Pajalich2 1 University of Rome “Sapienza”, Institute of Gynecology and Obstetrics, Viale del Policlinico, 00155 Rome, Italy 2 Ars Medica spa, Via Ferrero di Cambiano Cesare 29, 00191 Rome, Italy Correspondence should be addressed to Maurizio Nordio; [email protected] Received 8 May 2013; Revised 27 August 2013; Accepted 27 August 2013 Academic Editor: Jack R. Wall Copyright © 2013 M. Nordio and R. Pajalich. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Hashimoto’s thyroiditis (HT), also known as chronic lymphocytic thyroiditis or chronic autoimmune thyroiditis, is the most common form of thyroiditis affecting more than 10% of females and 2% of males. The present study aims to evaluate the beneficial effect of a combined treatment, Myo-Inositol plus selenomethionine, on subclinical hypothyroidism. Methods. The study was designed as a double-blind randomized controlled trial. Eligible patients were women diagnosed with subclinical hypothyroidism having Tg antibodies (TgAb) titer higher than 350 IU/mL. Outcome measures were Thyroid Stimulating Hormone (TSH) levels, thyroid peroxidase antibodies (TPOAb) and TgAb titer, selenium, and Myo-Inositol plasma concentration. Results. In the present paper, we demonstrated that the beneficial effects obtained by selenomethionine treatment on patients affected by subclinical hypothyroidism, likely due to the presence of autoantibody (TPOAb and TgAb), are further improved by cotreatment with Myo-Inositol.
  • Estradiol-17Β Pharmacokinetics and Histological Assessment Of

    Estradiol-17Β Pharmacokinetics and Histological Assessment Of

    animals Article Estradiol-17β Pharmacokinetics and Histological Assessment of the Ovaries and Uterine Horns following Intramuscular Administration of Estradiol Cypionate in Feral Cats Timothy H. Hyndman 1,* , Kelly L. Algar 1, Andrew P. Woodward 2, Flaminia Coiacetto 1 , Jordan O. Hampton 1,2 , Donald Nickels 3, Neil Hamilton 4, Anne Barnes 1 and David Algar 4 1 School of Veterinary Medicine, Murdoch University, Murdoch 6150, Australia; [email protected] (K.L.A.); [email protected] (F.C.); [email protected] (J.O.H.); [email protected] (A.B.) 2 Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne 3030, Australia; [email protected] 3 Lancelin Veterinary Hospital, Lancelin 6044, Australia; [email protected] 4 Department of Biodiversity, Conservation and Attractions, Locked Bag 104, Bentley Delivery Centre 6983, Australia; [email protected] (N.H.); [email protected] (D.A.) * Correspondence: [email protected] Received: 7 September 2020; Accepted: 17 September 2020; Published: 21 September 2020 Simple Summary: Feral cats (Felis catus) have a devastating impact on Australian native fauna. Several programs exist to control their numbers through lethal removal, using tools such as baiting with toxins. Adult male cats are especially difficult to control. We hypothesized that one way to capture these male cats is to lure them using female cats. As female cats are seasonal breeders, a method is needed to artificially induce reproductive (estrous) behavior so that they could be used for this purpose year-round (i.e., regardless of season).
  • Pseudopregnancy in Bitch. How to Support the Owner and the Animal?

    Pseudopregnancy in Bitch. How to Support the Owner and the Animal?

    Pseudopregnancy in bitch. How to support the owner and the animal? Michał Jank, DVM Tomasz Ciszewski, DVM Almost every owner of an unspayed female dog must have experienced at least once the symptoms of pseudopregnancy in their pet. These symptoms, even if sometimes significantly different in terms of their intensity and duration, always cause worries and in most cases make the owner seek advice at a veterinary surgery. Even though the most effective solution to this problem remains hormonal therapy, many owners search for other solutions which will be either more “natural” or economically beneficial. Introduction Pseudopregnancy always accompanies the long luteal phase in unspayed and not pregnant female dogs. It is a physiological condition, typical for canine and results mainly from a specific course of the reproduction of free-living animals representing this genus. In free-living packs of canines it is only one female dog (the alpha female) which is really pregnant, while other females are psudo-pregnant in order to prepare their lactation for the time when the alpha female delivers. Thus the pack protects itself in the case the alpha female is too weak after the labour to take care of the newborns or she becomes an easy target for other predators. In such situations other females in the pack begin their lactation exactly at the moment of the labour (the canine luteal phase always lasts for more or less the same period of time irrespective of whether the female is really or pseudo- pregnant) and they act as “wet nurses” thanks to which the little ones increase their chances of survival even if their biological mother dies.
  • Canine Reproductive Disorders

    Canine Reproductive Disorders

    Vet Times The website for the veterinary profession https://www.vettimes.co.uk Canine reproductive disorders Author : Jennifer Cartwright Categories : RVNs Date : November 1, 2011 Jennifer Cartwright RVN A1, discusses the variety of issues that can lead an owner to ask if their pet should be neutered Summary INpractice, while running our nurse clinics, we are often asked about the benefits of neutering. This is something a nurse should feel confident speaking about, as this will give clients faith in your knowledge and confidence in your practice. It is very stressful for clients to leave their pet with the practice, but if they trust you it makes the experience a little easier for them. This article aims to recap and revise common reproductive disorders in the dog and provide the reader with a better understanding when answering the “should I neuter my dog?” question. For ease of reading, the article is separated into female and male conditions. Key words neutering, reproduction, prevention, hormonal, congenital Conditions affecting female dogs Follicular cysts This condition is most common in older bitches that have previously had normal seasons. • Symptoms. The bitch will tend to have a longer pro-oestrus and a thickened vulval discharge for 1 / 7 approximately four weeks afterwards. The season tends to cease due to the lack of luteinising hormone. • Diagnosis. Ultrasound is useful, as it will show larger follicles, such as cystic follicles. Cytology of the vagina may be useful, as it will show cornified cells that will not alter at late pro-oestrus. Usually, these cells would not be visible at this stage in the cycle.
  • Global Importance of Selenium and Its Relation to Human Health - Combs, Jr., G.F

    Global Importance of Selenium and Its Relation to Human Health - Combs, Jr., G.F

    IMPACTS OF AGRICULTURE ON HUMAN HEALTH AND NUTRITION – Vol. I - Global Importance of Selenium and its Relation to Human Health - Combs, Jr., G.F. GLOBAL IMPORTANCE OF SELENIUM AND ITS RELATION TO HUMAN HEALTH Combs, Jr., G.F. Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA Keywords: Selenium, selenide, methylselenol, selenite, selenocysteine, selenomethionine, methylselenocysteine, cardiomyopathy, Keshan Disease, Kaschin- Beck Disease, cancer, chemoprevention, selenoenzymes, immune system, apoptosis, carcinogenesis Contents 1. Introduction 2. Metabolic Roles of Selenium 3. Selenium in Food Systems 3.1. Fundamental Importance of Soil Selenium 3.2. Selenium Cycle 3.3. Selenium in Plant Materials 3.4. Selenium in Animal Products 3.5. Selenium in Human Diets 3.6. Selenium Bioavailability 4. Global Variation in Selenium Status 5. Selenium and Human Disease 5.1. Selenium Deficiency Disorders 5.2. Keshan Disease 5.3. Kaschin-Beck Disease 5.4. Iodine Deficiency Diseases 5.5. Selenium Status and Other Diseases 5.6. Selenium Status and Malnutrition 6. Selenium as an Anti-Carcinogen 6.1. Background 6.2. Clinical Trial Results 6.3. Mechanisms of Selenium Anti-Carcinogenesis 7. Selenosis 8. Enhancing Selenium in Food Systems 8.1. SeleniumUNESCO as a Resource Input – EOLSS 8.2. Production of Selenium-Enriched Foods 9. Conclusions Glossary SAMPLE CHAPTERS Bibliography Biographical Sketch Summary Selenium is an essential biological trace element. It is an essential constituent of several enzymes in which it is present in the form of the unusual amino acid selenocysteine (SeCys). Selenium intakes of at least 40 mcg per day appear to be required to support ©Encyclopedia of Life Support Systems (EOLSS) IMPACTS OF AGRICULTURE ON HUMAN HEALTH AND NUTRITION – Vol.
  • Clinical Applications of Prostaglandins in Dogs and Cats Edward C

    Clinical Applications of Prostaglandins in Dogs and Cats Edward C

    Volume 44 | Issue 2 Article 5 1982 Clinical Applications of Prostaglandins in Dogs and Cats Edward C. Briles Iowa State University Lawrence E. Evans Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/iowastate_veterinarian Part of the Lipids Commons, and the Small or Companion Animal Medicine Commons Recommended Citation Briles, Edward C. and Evans, Lawrence E. (1982) "Clinical Applications of Prostaglandins in Dogs and Cats," Iowa State University Veterinarian: Vol. 44 : Iss. 2 , Article 5. Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol44/iss2/5 This Article is brought to you for free and open access by the Journals at Iowa State University Digital Repository. It has been accepted for inclusion in Iowa State University Veterinarian by an authorized editor of Iowa State University Digital Repository. For more information, please contact [email protected]. Clinical Applications of Prostaglandins in Dogs and Cats by Edward C. Briles, DVM* Lawrence E. Evans, DVM, PhD** In the biological sciences today there are few previously been shown to make smooth muscle 3 4 substances that generate as much interest as contract. • It wasn't until 1957 that two pro­ prostaglandins. They have found widespread staglandins (PGE l, PGF la) were isolated in use in veterinary medicine, yet are only ap­ pure crystalline form and soon more pro­ proved by the FDA for specific uses in cattle staglandins were characterized, all of which and horses. However, practical applications in were found to be 20-carbon unsaturated car­ the dog and cat have been reported by clini­ boxylic acids with a cyclopentane ring.
  • Null Mutation of the Prolactin Receptor Gene Produces Multiple Reproductive Defects in the Mouse

    Null Mutation of the Prolactin Receptor Gene Produces Multiple Reproductive Defects in the Mouse

    Downloaded from genesdev.cshlp.org on September 25, 2021 - Published by Cold Spring Harbor Laboratory Press Null mutation of the prolactin receptor gene produces multiple reproductive defects in the mouse Christopher J. Ormandy/ Anne Camus,^ Jacqueline Barra,^ Diane Damotte,^ Brian Lucas/ Helene Buteau/ Marc Edery/ Nicole Brousse,^ Charles Babinet/ Nadine Binart/'* and Paul A. Kelly^ 4nstitut National de la Sante et de la Recherche Medicale (INSERM) Unite 344, Endocrinologie Moleculaire Faculte de Medecine Necker, Paris, France; ^Unite de Biologic du Developpement Unites de Recherches Associees Centre National de la Recherche Scientifique (CNRS) IP 1960, Institut Pasteur, Paris, France; ^Service d'Anatomo-Pathologie, Hopital Necker-Enfants Malades, Paris, France Mice carrying a germ-line null mutation of the prolactin receptor gene have been produced by gene targeting in embryonic stem cells. Heterozygous females showed almost complete failure of lactation attributable to greatly reduced mammary gland development after their first, but not subsequent, pregnancies. Homozygous females were sterile owing to a complete failure of embryonic implantation. Moreover, they presented multiple reproductive abnormalities, including irregular cycles, reduced fertilization rates, defective preimplantation embryonic development, and lack of pseudopregnancy. Half of the homozygous males were infertile or showed reduced fertility. This work establishes the prolactin receptor as a key regulator of mammalian reproduction, and provides the first total ablation model to further study the role of the prolactin receptor and its ligands. [Key Words: Prolactin receptor gene; mouse reproduction] Received September 23, 1996; revised version accepted November 22, 1996. Prolactin is a 23-kD peptide synthesized and secreted by varying levels in virtually all tissues, both adult and fetal the lactotrophic cells of the anterior pituitary of all ver­ (Nagano and Kelly 1994; Freemark et al.
  • Biological Effects of Selenium Compounds with a Particular Attention to the Ontogenetic Development

    Biological Effects of Selenium Compounds with a Particular Attention to the Ontogenetic Development

    Physiol. Res. 61 (Suppl. 1): S19-S34, 2012 https://doi.org/10.33549/physiolres.932327 REVIEW Biological Effects of Selenium Compounds With a Particular Attention to the Ontogenetic Development I. OŠŤÁDALOVÁ1,2 1Centre for Cardiovascular Research, Prague, Czech Republic, 2Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic Received January 23, 2012 Accepted May 3, 2012 Summary Introduction Selenium is a trace element that is essential for living organism. Its beneficial effect is, however, expressed in a very narrow Selenium is a trace element that is essential for dosage range: the high and low doses of selenium are connected living organisms. The only source of selenium for with pathological manifestations. The toxicity depends on the mammalian food chain is the soil. The amount of chemical form of selenium, state of organism, interactions with selenium in the soil is not equal; it depends on the nature heavy metals and on the stage of ontogenetic development. of soil and in particular on its pH. There are geographic Whereas one dose of sodium selenite (20 μmol/kg b.w.) is lethal areas with high content of selenium e.g. in China, USA in adult rats, suckling rats are entirely resistant. However, within and Canada. On the other hand, there are areas with very one week after administration of the same dose, cataract of eye low content of selenium as other areas in China, Finland lens developed. The highest incidence of cataract was observed and New Zealand (Robinson and Thompson 1981, in 10-day-old animals and it decreased until day 20.
  • Comparative Effect of Selenium in Wheat, Barley, Fish Meal and Sodium Selenite for Prevention of Exudative Diathesis in Chicks

    Comparative Effect of Selenium in Wheat, Barley, Fish Meal and Sodium Selenite for Prevention of Exudative Diathesis in Chicks

    Acta vet. scand. 1986, 27, 461-478. From the Department of Clinical Nutrition, College of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden., and the Department of Biochemistry, College of Veterinary Medicine, Hels.inki, Finland. COMPARATIVE EFFECT OF SELENIUM IN WHEAT, BARLEY, FISH MEAL AND SODIUM SELENITE FOR PREVENTION OF EXUDATIVE DIATHESIS IN CHICKS By Saifeldin Hassan HASSAN, SAIFELDIN: Comparative ef{ect of selenium in wheat, barley, fish meal and sodium selenite for prevention of exudative diathesis in chicks. Acta vet. scand. 198-&, 27, 4-01-478. - Groups af White Leghorn chicks obtained from dams deprived on selenium (Se), were fed from hatching a low-Se-vitamin E basal diet alone, or supple­ mented with 0.02, 0.04, 0.06 or 0.08 mg Se/kg diet, as sodium selenite (Na2SeOa · 5H20), wheat, barley or fish meal. Prevention of the Se­ vitamin E deficiency responsive disease exudative diathesis (ED) as it was clinical observed, induction of the plasma Se dependent en­ zyme glutathione peroxidase (GSH-Px) activity, an:d Se concentration in the cardiac muscle were observed to be dietary Se level and source dependent. Slope ratio assay was applied to estimate the biological availability of Se in the natural sources relative to Se in sodium selenite. For the prevention of ED, the bioavailability of Se in wheat, bairley and fish meal was 99, 85 an.d 80 %, respectively. The increase in the plasma GSH-Px activity revealed a bioavailability for Se in wheat, barley and fish meal of 79, 71 and 66 %, respectively. Using retenlion of Se in the cardiac muscle as the bioass•ay, a bioavaiilability of 108, 87 and 100 % was calculaited for wheat, barley aind fish meal Se, respectively.
  • Selenium-Containing Enzymes in Mammals: Chemical Perspectives

    Selenium-Containing Enzymes in Mammals: Chemical Perspectives

    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Publications of the IAS Fellows J. Chem. Sci., Vol. 117, No. 4, July 2005, pp. 287–303. © Indian Academy of Sciences. Selenium-containing enzymes in mammals: Chemical perspectives GOURIPRASANNA ROY, BANI KANTA SARMA, PRASAD P PHADNIS and G MUGESH* Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India e-mail: [email protected] MS received 22 March 2005; accepted 6 June 2005 Abstract. The chemical and biochemical route to the synthesis of the 21st amino acid in living systems, selenocysteine, is described. The incorporation of this rare amino acid residue into proteins is described with emphasis on the role of monoselenophosphate as selenium source. The role of selenocysteine moiety in natural mammalian enzymes such as glutathione peroxidase (GPx), iodothyronine deiodinase (ID) and thioredoxin reductase (TrxR) is highlighted and the effect of other amino acid residues located in close proximity to selenocysteine is described. It is evident from various studies that two amino acid residues, tryptophan and glutamine, appear in identical positions in all known members of the GPx family. Ac- cording to the three-dimensional structure established for bovine GPx, these residues could constitute a catalytic triad in which the selenol group of the selenocysteine is both stabilized and activated by hydro- gen bonding with the imino group of the tryptophan (Trp) residue and with the amido group of the gluta- mine (Gln) residue. The ID enzymes, on the other hand, do not possess any Trp or Gln residues in close proximity to selenium, but contain several histidine residues, which may play important roles in the ca- talysis.
  • Research Article Combined Treatment with Myo-Inositol and Selenium Ensures Euthyroidism in Subclinical Hypothyroidism Patients with Autoimmune Thyroiditis

    Research Article Combined Treatment with Myo-Inositol and Selenium Ensures Euthyroidism in Subclinical Hypothyroidism Patients with Autoimmune Thyroiditis

    Hindawi Publishing Corporation Journal of Thyroid Research Volume 2013, Article ID 424163, 5 pages http://dx.doi.org/10.1155/2013/424163 Research Article Combined Treatment with Myo-Inositol and Selenium Ensures Euthyroidism in Subclinical Hypothyroidism Patients with Autoimmune Thyroiditis Maurizio Nordio1 and Raffaella Pajalich2 1 University of Rome “Sapienza”, Institute of Gynecology and Obstetrics, Viale del Policlinico, 00155 Rome, Italy 2 Ars Medica spa, Via Ferrero di Cambiano Cesare 29, 00191 Rome, Italy Correspondence should be addressed to Maurizio Nordio; [email protected] Received 8 May 2013; Revised 27 August 2013; Accepted 27 August 2013 Academic Editor: Jack R. Wall Copyright © 2013 M. Nordio and R. Pajalich. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Hashimoto’s thyroiditis (HT), also known as chronic lymphocytic thyroiditis or chronic autoimmune thyroiditis, is the most common form of thyroiditis affecting more than 10% of females and 2% of males. The present study aims to evaluate the beneficial effect of a combined treatment, Myo-Inositol plus selenomethionine, on subclinical hypothyroidism. Methods. The study was designed as a double-blind randomized controlled trial. Eligible patients were women diagnosed with subclinical hypothyroidism having Tg antibodies (TgAb) titer higher than 350 IU/mL. Outcome measures were Thyroid Stimulating Hormone (TSH) levels, thyroid peroxidase antibodies (TPOAb) and TgAb titer, selenium, and Myo-Inositol plasma concentration. Results. In the present paper, we demonstrated that the beneficial effects obtained by selenomethionine treatment on patients affected by subclinical hypothyroidism, likely due to the presence of autoantibody (TPOAb and TgAb), are further improved by cotreatment with Myo-Inositol.