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Akinrinde A, Adigun K, Mustapha O. Cobalt-induced neuro-behavioural alterations are accompanied by profound Purkinje cell and gut-associated responses in rats. Environ Anal Health Toxicol 2023; 38:e2023010-0. [PMID: 37933104 PMCID: PMC10628406 DOI: 10.5620/eaht.2023010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 04/21/2023] [Indexed: 11/08/2023] Open
Abstract
Metal ions including cobalt (Co) ions reportedly exhibit neurotoxic and antimicrobial properties. We hypothesized that oral exposure to Co may have implications for gut-dysbiosis with possible alterations of microbiota-gut-brain signaling in the host. In this preliminary study, we sought to examine whether exposure of male Wistar rats to cobalt chloride (CoCl2) at 0, 25, 50 and 100 mg/kg for two weeks affects select neurobehavioural indices, vagus nerve and brain morphology along with evaluation of associated changes in faecal bacterial flora, faecal fatty acids and the morphology of the intestines. CoCl2-exposed rats showed a dose-dependent reduction in hanging latency in the hanging wire (HW) test, reduced tendency to recognize novel objects in a Novel Object recognition (NOR) test, but increased interaction with open arms in the elevated plus maze (EPM) test, compared to controls. There were dose-dependent reductions in total heterotrophic count, coliforms, E. coli, Enterococcal and Lactobacilli counts in the faeces. Administration of CoCl2 at 100 mg/kg evoked the appearance of unsaturated fatty acids including palmitoleic, oleic and linoleic acids in the faeces as detected by gas chromatography-flame ion detection (GD-FID) analysis using fatty acid methyl esters (FAME) standards. Histopathological examination revealed chromatolysis of Purkinje cells in the cerebellum, although no significant lesions were present in the vagus nerve isolated from all the groups. In the intestines, there was moderate to severe infiltration of inflammatory cells into the duodenum, ileum, jejunum and colon while villi erosions were seen prominently in the ileum. These initial findings suggest that short-term exposure to Co can lead to gut-associated changes that may underlie neurotoxicity and alterations in behavior induced by Co.
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Affiliation(s)
- Akinleye Akinrinde
- Department of Veterinary Physiology and Biochemistry, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Kabirat Adigun
- Department of Veterinary Physiology and Biochemistry, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Oluwaseun Mustapha
- Department of Veterinary Anatomy, College of Veterinary Medicine, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
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Castilla R, Ruffa FV, Bancalari I, Fernández Vivanco M, Lallopizzo C, Torasso N, Farcy N, Gutierrez C, Bonazzolaa P. Cobalt chloride postconditioning as myoprotective therapy in cardiac ischemia-reperfusion. Pflugers Arch 2022; 474:743-752. [PMID: 35585327 DOI: 10.1007/s00424-022-02703-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/11/2022] [Accepted: 05/03/2022] [Indexed: 11/24/2022]
Abstract
Since damage induced by ischemia-reperfusion (I/R) involves alterations in Ca2+ homeostasis and is reduced by ischemic postconditioning (IP) and that CoCl2 can trigger changes resembling the response to a hypoxic event in normoxia and its blockade on Ca2+ current in heart muscle, our aim was to evaluate CoCl2 as an IP therapeutic tool. Mechanic and energetic parameters of isolated and arterially perfused male Wistar rat heart ventricles were simultaneously analyzed in a model of I/R in which 0.23 mmol/L CoCl2 was introduced upon reperfusion and kept or withdrawn after 20 min or introduced after 20 min of reperfusion. The presence of CoCl2 did not affect diastolic pressure but increased post-ischemic contractile recovery, which peaked at 20 min and decreased at the end of reperfusion. This decrease was prevented when CoCl2 was removed at 20 min of reperfusion. Total heat release increased throughout reperfusion, while economy increased between 15 and 25 min. No effect was observed when CoCl2 was introduced at 20 min of reperfusion. In addition, both the area under the contracture curve evoked by 10 mmol/L caffeine-36 mmol/L Na+ and the contracture tension relaxation rate were higher with CoCl2.Furthermore, CoCl2 decreased the number of arrhythmias during reperfusion and the ventricular damaged area. The presence of CoCl2 in reperfusion induces cardioprotection consistent with the improvement in cellular calcium handling. The use of CoCl2 constitutes a potential cardioprotective tool of clinical relevance.
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Affiliation(s)
- Rocío Castilla
- CONICET, Instituto Alberto C Taquini de Investigaciones en Medicina Traslacional (IATIMET) C1122AAJ, Universidad de Buenos Aires, Marcelo T. de Alvear, 2270- C1122AAJ, Buenos Aires, Argentina.
| | - Facundo Vigón Ruffa
- CONICET, Instituto Alberto C Taquini de Investigaciones en Medicina Traslacional (IATIMET) C1122AAJ, Universidad de Buenos Aires, Marcelo T. de Alvear, 2270- C1122AAJ, Buenos Aires, Argentina
| | - Ignacio Bancalari
- CONICET, Instituto Alberto C Taquini de Investigaciones en Medicina Traslacional (IATIMET) C1122AAJ, Universidad de Buenos Aires, Marcelo T. de Alvear, 2270- C1122AAJ, Buenos Aires, Argentina
| | - Mercedes Fernández Vivanco
- CONICET, Instituto Alberto C Taquini de Investigaciones en Medicina Traslacional (IATIMET) C1122AAJ, Universidad de Buenos Aires, Marcelo T. de Alvear, 2270- C1122AAJ, Buenos Aires, Argentina
| | - Carla Lallopizzo
- CONICET, Instituto Alberto C Taquini de Investigaciones en Medicina Traslacional (IATIMET) C1122AAJ, Universidad de Buenos Aires, Marcelo T. de Alvear, 2270- C1122AAJ, Buenos Aires, Argentina
| | - Nicolás Torasso
- Facultad de Ciencias Exactas Y Naturales, Instituto de Física de Buenos Aires (IFIBA-CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Nicole Farcy
- CONICET, Instituto Alberto C Taquini de Investigaciones en Medicina Traslacional (IATIMET) C1122AAJ, Universidad de Buenos Aires, Marcelo T. de Alvear, 2270- C1122AAJ, Buenos Aires, Argentina
| | - Christopher Gutierrez
- CONICET, Instituto Alberto C Taquini de Investigaciones en Medicina Traslacional (IATIMET) C1122AAJ, Universidad de Buenos Aires, Marcelo T. de Alvear, 2270- C1122AAJ, Buenos Aires, Argentina
| | - Patricia Bonazzolaa
- CONICET, Instituto Alberto C Taquini de Investigaciones en Medicina Traslacional (IATIMET) C1122AAJ, Universidad de Buenos Aires, Marcelo T. de Alvear, 2270- C1122AAJ, Buenos Aires, Argentina
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Knoop A, Planitz P, Wüst B, Thevis M. Analysis of cobalt for human sports drug testing purposes using ICP‐ and LC‐ICP‐MS. Drug Test Anal 2020; 12:1666-1672. [DOI: 10.1002/dta.2962] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 12/13/2022]
Affiliation(s)
- Andre Knoop
- Institute of Biochemistry, Center for Preventive Doping Research German Sport University Cologne Cologne Germany
| | - Peter Planitz
- Agilent Technologies GmbH und Co. KG Waldbronn Germany
| | - Bernhard Wüst
- Agilent Technologies GmbH und Co. KG Waldbronn Germany
| | - Mario Thevis
- Institute of Biochemistry, Center for Preventive Doping Research German Sport University Cologne Cologne Germany
- European Monitoring Center for Emerging Doping Agents (EuMoCEDA) Cologne/Bonn Germany
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Sethi K, Rao K, Bolton D, Patel O, Ischia J. Targeting HIF-1 α to Prevent Renal Ischemia-Reperfusion Injury: Does It Work? Int J Cell Biol 2018; 2018:9852791. [PMID: 30595695 PMCID: PMC6286753 DOI: 10.1155/2018/9852791] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/14/2018] [Indexed: 12/26/2022] Open
Abstract
Partial nephrectomy (open or minimally invasive) usually requires temporary renal arterial occlusion to limit intraoperative bleeding and improve access to intrarenal structures. This is a time-critical step due to the critical ischemia period of renal tissue. Prolonged renal ischemia may lead to irreversible nephron damage in the remaining tissue and, ultimately, chronic kidney disease. This is potentiated by the incompletely understood ischemia-reperfusion injury (IRI). A key mechanism in IRI prevention appears to be the upregulation of an intracellular transcription protein, Hypoxia-Inducible Factor (HIF). HIF mediates metabolic adaptation, angiogenesis, erythropoiesis, cell growth, survival, and apoptosis. Upregulating HIF-1α via ischemic preconditioning (IPC) or drugs that simulate hypoxia (hypoxia-mimetics) has been investigated as a method to reduce IRI. While many promising chemical agents have been trialed for the prevention of IRI in small animal studies, all have failed in human trials. The aim of this review is to highlight the techniques and drugs that target HIF-1α and ameliorate IRI associated with renal ischemia. Developing a technique or drug that could reduce the risk of acute kidney injury associated with renal IRI would have an immediate worldwide impact on multisystem surgeries that would otherwise risk ischemic tissue injury.
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Affiliation(s)
- Kapil Sethi
- Department of Surgery, Austin Health, University of Melbourne, Heidelberg, VIC, Australia
- Urology Unit, Austin Health, Heidelberg, VIC, Australia
| | - Kenny Rao
- Department of Surgery, Austin Health, University of Melbourne, Heidelberg, VIC, Australia
- Urology Unit, Austin Health, Heidelberg, VIC, Australia
| | - Damien Bolton
- Department of Surgery, Austin Health, University of Melbourne, Heidelberg, VIC, Australia
- Urology Unit, Austin Health, Heidelberg, VIC, Australia
| | - Oneel Patel
- Department of Surgery, Austin Health, University of Melbourne, Heidelberg, VIC, Australia
| | - Joseph Ischia
- Department of Surgery, Austin Health, University of Melbourne, Heidelberg, VIC, Australia
- Urology Unit, Austin Health, Heidelberg, VIC, Australia
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Hoffmeister T, Schwenke D, Krug O, Wachsmuth N, Geyer H, Thevis M, Byrnes WC, Schmidt WFJ. Effects of 3 Weeks of Oral Low-Dose Cobalt on Hemoglobin Mass and Aerobic Performance. Front Physiol 2018; 9:1289. [PMID: 30283349 PMCID: PMC6157393 DOI: 10.3389/fphys.2018.01289] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 08/27/2018] [Indexed: 11/13/2022] Open
Abstract
Introduction: Cobalt ions (Co2+) stabilize HIFα and increase endogenous erythropoietin (EPO) production creating the possibility that Co2+ supplements (CoSupp) may be used as performance enhancing substances. The aim of this study was to determine the effects of a small oral dosage of CoSupp on hemoglobin mass (Hbmass) and performance with the objective of providing the basis for establishing upper threshold limits of urine [Co2+] to detect CoSupp misuse in sport. Methods: Twenty-four male subjects participated in a double-blind placebo-controlled study. Sixteen received an oral dose of 5 mg of ionized Co2+ per day for 3 weeks, and eight served as controls. Blood and urine samples were taken before the study, during the study and up to 3 weeks after CoSupp. Hbmass was determined by the CO-rebreathing method at regular time intervals, and VO2max was determined before and after the CoSupp administration period. Results: In the Co2+ group, Hbmass increased by 2.0 ± 2.1% (p < 0.001) while all the other analyzed hematological parameters did not show significant interactions of time and treatment. Hemoglobin concentration ([Hb]) and hematocrit (Hct) tended to increase (p = 0.16, p = 0.1) and also [EPO] showed a similar trend (baseline: 9.5 ± 3.0, after 2 weeks: 12.4 ± 5.2 mU/ml). While mean VO2max did not change, there was a trend for a positive relationship between changes in Hbmass and changes in VO2max immediately after CoSupp (r = 0.40, p = 0.11). Urine [Co2+] increased from 0.4 ± 0.3 to 471.4 ± 384.1 ng/ml (p < 0.01) and remained significantly elevated until 2 weeks after cessation. Conclusion: An oral Co2+ dosage of 5 mg/day for 3 weeks effectively increases Hbmass with a tendency to increase hemoglobin concentration ([Hb]) and hematocrit (Hct). Because urine Co2+ concentration remains increased for 2 weeks after cessation, upper limit threshold values for monitoring CoSupp can be established.
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Affiliation(s)
- Torben Hoffmeister
- Department of Sports Medicine and Sports Physiology, University of Bayreuth, Bayreuth, Germany
| | - Dirk Schwenke
- Institute of Doping Analysis und Sports Biochemistry, University of Dresden, Dresden, Germany
| | - Oliver Krug
- Institute of Biochemistry, German Sport University, Cologne, Germany
| | - Nadine Wachsmuth
- Department of Sports Medicine and Sports Physiology, University of Bayreuth, Bayreuth, Germany
| | - Hans Geyer
- Institute of Biochemistry, German Sport University, Cologne, Germany
| | - Mario Thevis
- Institute of Biochemistry, German Sport University, Cologne, Germany
| | - William C Byrnes
- Department of Integrative Physiology, University of Colorado, Boulder, CO, United States
| | - Walter F J Schmidt
- Department of Sports Medicine and Sports Physiology, University of Bayreuth, Bayreuth, Germany
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Paustenbach DJ, Tvermoes BE, Unice KM, Finley BL, Kerger BD. A review of the health hazards posed by cobalt. Crit Rev Toxicol 2013; 43:316-62. [DOI: 10.3109/10408444.2013.779633] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Gluhcheva Y, Atanasov V, Ivanova J, Mitewa M. Cobalt-induced changes in the spleen of mice from different stages of development. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2012; 75:1418-1422. [PMID: 23095160 DOI: 10.1080/15287394.2012.721176] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Cobalt(II) accumulates in organs such as spleen, kidneys, heart, and liver. The aim of the present study was to investigate the effects of cobalt ethylenediamine tetraacetic acid (Co-EDTA) on spleen of developing mice. Pregnant BALB/c mice in late gestation were subjected to Co-EDTA treatment at daily doses of 75 or 125 mg/kg in drinking water, which continued until d 90 of the newborn pups. The newborn pups were sacrificed on d 18, 25, 30, 45, 60, and 90, which correspond to different stages of development. Spleens were excised, weighed, and processed for histological analysis. Spleen index (SI) was calculated as a ratio of spleen weight to body weight. Cobalt(II) bioaccumulation in spleen was determined using flame atomic absorption spectrometry (FAAS). Preliminary results showed that chronic treatment of mice with low- or high-dose Co-EDTA disturbed extramedullary hematopoiesis in the spleen. The number of megakaryocytes was reduced compared to controls. SI was also reduced in d 18 mice treated with low- or high-dose Co-EDTA. However, exposure to 75 mg/kg led to an increase of SI in all other experimental groups. FAAS analysis revealed significant cobalt(II) accumulation in spleen of treated mice. The Co(II) levels in spleens of d 18 mice were highest compared to other experimental groups, indicating that at this period mice are more sensitive to treatment. Exposure to cobalt-EDTA resulted in accumulation of Co(II) in spleen, altered SI, and hematopoiesis. Immature mice appear to be more sensitive to chronic treatment than adults.
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Affiliation(s)
- Yordanka Gluhcheva
- Institute of Experimental Morphology, Pathology, and Anthropology With Museum, Bulgarian Academy of Sciences, Sofia, Bulgaria.
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Gluhcheva Y, Atanasov V, Zhorova R, Madzharova M, Ivanova J, Mitewa M. Cobalt Bioaccumulation in Mouse Blood Plasma and Liver. BIOTECHNOL BIOTEC EQ 2010. [DOI: 10.1080/13102818.2010.10817853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Lippi G, Franchini M, Salvagno GL, Guidi GC. Biochemistry, physiology, and complications of blood doping: facts and speculation. Crit Rev Clin Lab Sci 2006; 43:349-91. [PMID: 16769597 DOI: 10.1080/10408360600755313] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Competition is a natural part of human nature. Techniques and substances employed to enhance athletic performance and to achieve unfair success in sport have a long history, and there has been little knowledge or acceptance of potential harmful effects. Among doping practices, blood doping has become an integral part of endurance sport disciplines over the past decade. The definition of blood doping includes methods or substances administered for non-medical reasons to healthy athletes for improving aerobic performance. It includes all means aimed at producing an increased or more efficient mechanism of oxygen transport and delivery to peripheral tissues and muscles. The aim of this review is to discuss the biochemistry, physiology, and complications of blood doping and to provide an update on current antidoping policies.
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Affiliation(s)
- Giuseppe Lippi
- Dipartimento di Scienze Morfologico-Biomediche, Istituto di Chimica e Microscopia Clinica, Università Degli Studi di Verona, Verona, Italy
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Lippi G, Franchini M, Guidi GC. Blood doping by cobalt. Should we measure cobalt in athletes? J Occup Med Toxicol 2006; 1:18. [PMID: 16863591 PMCID: PMC1550414 DOI: 10.1186/1745-6673-1-18] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2006] [Accepted: 07/24/2006] [Indexed: 11/12/2022] Open
Abstract
Background Blood doping is commonplace in competitive athletes who seek to enhance their aerobic performances through illicit techniques. Presentation of the hypothesis Cobalt, a naturally-occurring element with properties similar to those of iron and nickel, induces a marked and stable polycythemic response through a more efficient transcription of the erythropoietin gene. Testing the hypothesis Although little information is available so far on cobalt metabolism, reference value ranges or supplementation in athletes, there is emerging evidence that cobalt is used as a supplement and increased serum concentrations are occasionally observed in athletes. Therefore, given the athlete's connatural inclination to experiment with innovative, unfair and potentially unhealthy doping techniques, cobalt administration might soon become the most suited complement or surrogate for erythropoiesis-stimulating substances. Nevertheless, cobalt administration is not free from unsafe consequences, which involve toxic effects on heart, liver, kidney, thyroid and cancer promotion. Implications of the hypothesis Cobalt is easily purchasable, inexpensive and not currently comprehended within the World Anti-Doping Agency prohibited list. Moreover, available techniques for measuring whole blood, serum, plasma or urinary cobalt involve analytic approaches which are currently not practical for antidoping laboratories. Thus more research on cobalt metabolism in athletes is compelling, along with implementation of effective strategies to unmask this potentially deleterious doping practice
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Affiliation(s)
- Giuseppe Lippi
- Istituto di Chimica e Microscopia Clinica, Dipartimento di Scienze Morfologico-Biomediche, Università degli Studi di Verona, Verona, Italy
| | - Massimo Franchini
- Servizio di Immunoematologia e Trasfusione, Azienda Ospedaliera di Verona, Verona, Italy
| | - Gian Cesare Guidi
- Istituto di Chimica e Microscopia Clinica, Dipartimento di Scienze Morfologico-Biomediche, Università degli Studi di Verona, Verona, Italy
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Lippi G, Franchini M, Guidi GC. Cobalt chloride administration in athletes: a new perspective in blood doping? Br J Sports Med 2006; 39:872-3. [PMID: 16244201 PMCID: PMC1725077 DOI: 10.1136/bjsm.2005.019232] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Blood doping is an illegal and unfair way of enhancing athletic performance by increasing the oxygen carrying capacity of the blood. Currently used methods usually involve stimulation of erythropoiesis. Gene therapy targeting the hypoxia inducible factor pathway may be an attractive alternative to traditional blood doping techniques. Hypoxia activates a large number of genes with essential roles in cell and tissue adaptation to low oxygen. Cobalt chloride is a well established chemical inducer of hypoxia-like responses such as erythropoiesis. Cobalt supplementation is not banned and therefore would not be detected by current anti-doping testing. Although there is as yet no direct or anecdotal evidence of cobalt chloride administration to athletes, its use should be warned against as being not only unfair but potentially dangerous.
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Affiliation(s)
- G Lippi
- Ist Chimica e Microscopia Clinica, Università di Verona, Verona, Italy.
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Yokel RA, Lasley SM, Dorman DC. The speciation of metals in mammals influences their toxicokinetics and toxicodynamics and therefore human health risk assessment. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2006; 9:63-85. [PMID: 16393870 DOI: 10.1080/15287390500196230] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Chemical form (i.e., species) can influence metal toxicokinetics and toxicodynamics and should be considered to improve human health risk assessment. Factors that influence metal speciation (and examples) include: (1) carrier-mediated processes for specific metal species (arsenic, chromium, lead and manganese), (2) valence state (arsenic, chromium, manganese and mercury), (3) particle size (lead and manganese), (4) the nature of metal binding ligands (aluminum, arsenic, chromium, lead, and manganese), (5) whether the metal is an organic versus inorganic species (arsenic, lead, and mercury), and (6) biotransformation of metal species (aluminum, arsenic, chromium, lead, manganese and mercury). The influence of speciation on metal toxicokinetics and toxicodynamics in mammals, and therefore the adverse effects of metals, is reviewed to illustrate how the physicochemical characteristics of metals and their handling in the body (toxicokinetics) can influence toxicity (toxicodynamics). Generalizing from mercury, arsenic, lead, aluminum, chromium, and manganese, it is clear that metal speciation influences mammalian toxicity. Methods used in aquatic toxicology to predict the interaction among metal speciation, uptake, and toxicity are evaluated. A classification system is presented to show that the chemical nature of the metal can predict metal ion toxicokinetics and toxicodynamics. Essential metals, such as iron, are considered. These metals produce low oral toxicity under most exposure conditions but become toxic when biological processes that utilize or transport them are overwhelmed, or bypassed. Risk assessments for essential and nonessential metals should consider toxicokinetic and toxicodynamic factors in setting exposure standards. Because speciation can influence a metal's fate and toxicity, different exposure standards should be established for different metal species. Many examples are provided which consider metal essentiality and toxicity and that illustrate how consideration of metal speciation can improve the risk assessment process. More examples are available at a website established as a repository for summaries of the literature on how the speciation of metals affects their toxicokinetics.
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Affiliation(s)
- Robert A Yokel
- Pharmaceutical Sciences, College of Pharmacy, and Graduate Center for Toxicology, University of Kentucky Medical Center, Lexington, KY 40536-0082, USA.
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