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Hombrecher K, Quass U, Sievering S, Schöppe A, Rauchfuss K. Contamination of food crops by unintentionally released PCB 47, PCB 51 and PCB 68 in the vicinity of silicone production sites and their relevance for human health assessment. CHEMOSPHERE 2022; 308:136392. [PMID: 36096305 DOI: 10.1016/j.chemosphere.2022.136392] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 06/15/2023]
Abstract
Since it was shown that silicone rubber production can unintentionally release PCBs, these production sites have become a focus of investigation. The use of the cross-linking agent bis(2,4)-dichlorobenzoylperoxide (2,4-DCBP) can lead to emissions of the PCB congeners PCB 47, PCB 51 and PCB 68 into the environment and cause their accumulation e. g. in food crops. To determine the presence and extent of this uptake, we used the newly developed method dandelion screening. Samples were taken from wild dandelion plants near nine production sites in North Rhine-Westphalia, Germany, and analysed for PCBs. In some cases, the regional orientation values for the maximum background level (OMB) were exceeded by up to nine times. Overall, background levels were exceeded at seven of the nine sites investigated and mitigation measures were initiated at the production sites. In order to validate the dandelion screening results, kale was exposed, which allowed for a health assessment. A wide-ranging consumption recommendation was then issued in four out of nine study areas. At this point in the investigations, risk reduction measures had already been implemented at all production sites investigated, so it can be assumed that the exposures at sites not yet in focus are significantly greater. This is a globally relevant problem, as 2,4-DCBP is used in many countries.
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Affiliation(s)
- Katja Hombrecher
- North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection (LANUV NRW), Wallneyer Str. 6, Essen, 45133, Germany.
| | - Ulrich Quass
- North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection (LANUV NRW), Wallneyer Str. 6, Essen, 45133, Germany
| | - Silvia Sievering
- North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection (LANUV NRW), Wallneyer Str. 6, Essen, 45133, Germany
| | - Angelika Schöppe
- North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection (LANUV NRW), Wallneyer Str. 6, Essen, 45133, Germany
| | - Knut Rauchfuss
- North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection (LANUV NRW), Wallneyer Str. 6, Essen, 45133, Germany
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Wang H, Adamcakova-Dodd A, Flor S, Gosse L, Klenov VE, Stolwijk JM, Lehmler HJ, Hornbuckle KC, Ludewig G, Robertson LW, Thorne PS. Comprehensive Subchronic Inhalation Toxicity Assessment of an Indoor School Air Mixture of PCBs. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:15976-15985. [PMID: 33256405 PMCID: PMC7879961 DOI: 10.1021/acs.est.0c04470] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Few in vivo inhalation studies have explored the toxicity of environmentally relevant mixtures of polychlorinated biphenyls (PCBs). The manufacture of industrial PCBs was banned in 1978, but PCBs continue to be formed in industrial and consumer products. Schools represent a significant source of airborne exposures to legacy and nonlegacy PCBs, placing children at risk. To evaluate the impact of these exposures, we generated an airborne mixture of PCBs, called the School Air Mixture (SAM), to match the profile of an older school from our adolescent cohort study. Female Sprague-Dawley rats were exposed either to SAM or filtered air in nose-only exposure systems, 4 h/day for 4 weeks. Congener-specific air and tissue PCB profiles were assessed using gas chromatography with tandem mass spectrometry (GC-MS/MS). PCB exposures recapitulated the target school air profile with a similarity coefficient, cos θ of 0.83. PCB inhalation yielded μg/g ∑209 PCB levels in tissues. Neurobehavioral testing demonstrated a modest effect on spatial learning and memory in SAM-exposed rats. PCB exposure induced oxidative stress in the liver and lungs, affected the maturational stages of hematopoietic stem cells, reduced telomerase activity in bone marrow cells, and altered the gut microbiota. This is the first study to emulate PCB exposures in a school and comprehensively evaluate toxicity.
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Affiliation(s)
- Hui Wang
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Andrea Adamcakova-Dodd
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Susanne Flor
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Laura Gosse
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Violet E. Klenov
- Department of Obstetrics and Gynecology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Jeffrey M. Stolwijk
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Keri C. Hornbuckle
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
- Department of Civil and Environmental Engineering, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Gabriele Ludewig
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Larry W. Robertson
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Peter S. Thorne
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
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Pillai MR, Keylock KT, Cromwell HC, Meserve LA. Exercise influences the impact of polychlorinated biphenyl exposure on immune function. PLoS One 2020; 15:e0237705. [PMID: 32833973 PMCID: PMC7444807 DOI: 10.1371/journal.pone.0237705] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 07/25/2020] [Indexed: 12/17/2022] Open
Abstract
Polychlorinated biphenyls (PCBs) are environmental pollutants and endocrine disruptors, harmfully affecting reproductive, endocrine, neurological and immunological systems. This broad influence has implications for processes such as wound healing, which is modulated by the immunological response of the body. Conversely, while PCBs can be linked to diminished wound healing, outside of PCB pollution systems, exercise has been shown to accelerate wound healing. However, the potential for moderate intensity exercise to modulate or offset the harmful effects of a toxin like PCB are yet unknown. A key aim of the present study was to examine how PCB exposure at different doses (0, 100, 500, 1000 ppm i.p.) altered wound healing in exercised versus non-exercised subgroups of mice. We examined PCB effects on immune function in more depth by analyzing the concentrations of cytokines, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6) and granulocyte macrophage colony stimulating factor (GM-CSF) in these wounds inflicted by punch biopsy. Mice were euthanized at Day 3 or Day 5 after PCB injection (n = 3-6) and skin excised from the wound area was homogenized and analyzed for cytokine content. Results revealed that wound healing was not signficantly impacted by either PCB exposure or exercise, but there were patterns of delays in healing that depended on PCB dose. Changes in cytokines were also observed and depended on PCB dose and exercise experience. For example, IL-1β concentrations in Day 5 mice without PCB administration were 33% less in exercised mice than mice not exercised. However, IL-1β concentrations in Day 3 mice administered 100 ppm were 130% greater in exercised mice than not exercisedmice. Changes in the other measured cytokines varied with mainly depressions at lesser PCB doses and elevations at higher doses. Exercise had diverse effects on cytokine levels, but increased cytokine levels in the two greater doses. Explanations for these diverse effects include the use of young animals with more rapid wound healing rates less affected by toxin exposure, as well as PCB-mediated compensatory effects at specific doses which could actually enhance immune function. Future work should examine these interactions in more detail across a developmental time span. Understanding how manipulating the effects of exposure to environemntal contaminants using behavioral modification could be very useful in certain high risk populations or exposed individuals.
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Affiliation(s)
- Mahesh R. Pillai
- Dept. of Biological Sciences, Bowling Green State University, Bowling Green, Ohio, United States of America
| | - K. Todd Keylock
- Dept. of Exercise Science, Bowling Green State University, Bowling Green, Ohio, United States of America
| | - Howard C. Cromwell
- Dept. of Psychology and J.P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, Ohio, United States of America
| | - Lee A. Meserve
- Dept. of Biological Sciences, Bowling Green State University, Bowling Green, Ohio, United States of America
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Shim HS, Park HJ, Lee MS, Ye M, Shim I. The role of the supramammillary area of the hypothalamus in cognitive functions. Anim Cells Syst (Seoul) 2018. [DOI: 10.1080/19768354.2018.1427627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Hyun Soo Shim
- Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - Hyun-Jung Park
- Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - Mi-Sook Lee
- Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - Minsook Ye
- Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - Insop Shim
- Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea
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Sun Y, Zhang Q, Wang H, Wang W. Quantum chemical investigation on the mechanism and kinetics of OH radical-initiated atmospheric oxidation of PCB-47. CHEMOSPHERE 2015; 133:53-60. [PMID: 25898309 DOI: 10.1016/j.chemosphere.2015.03.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 03/08/2015] [Accepted: 03/19/2015] [Indexed: 06/04/2023]
Abstract
The OH radical-initiated atmospheric oxidation degradation of 2,2',4,4'-tetrachlorobiphenyl (PCB-47) was investigated by using quantum chemical calculations. All possible pathways involved in the oxidation process were discussed. Potential barriers and reaction heats have been obtained to assess the energetically favorable reaction pathways and the relatively stable products. The study shows that the OH radicals are more likely to attack the C3 and C5 atom of the aromatic ring in the PCB-47 molecule to form PCB-OH adducts. Subsequent reactions are the addition of O2 or NO2 molecule to the PCB-OH adducts at the ortho position of the OH group. Water molecule plays an important role during the whole degradation process. The individual and overall rate constants were calculated by using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory over the temperature range of 180-370K. At 298K, the atmospheric lifetime of PCB-47 determined by OH radicals is about 9.1d. The computational results are crucial to risk assessment and pollution prevention of PCBs.
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Affiliation(s)
- Yanhui Sun
- Environment Research Institute, Shandong University, Jinan 250100, PR China
| | - Qingzhu Zhang
- Environment Research Institute, Shandong University, Jinan 250100, PR China.
| | - Hui Wang
- School of Environment, Tsinghua University, Beijing 100084, PR China.
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Jinan 250100, PR China
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Association between Several Persistent Organic Pollutants and Thyroid Hormone Levels in Cord Blood Serum and Bloodspot of the Newborn Infants of Korea. PLoS One 2015; 10:e0125213. [PMID: 25965908 PMCID: PMC4429016 DOI: 10.1371/journal.pone.0125213] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 03/23/2015] [Indexed: 11/19/2022] Open
Abstract
Current knowledge on adverse endocrine disruption effects of persistent organic pollutants (POPs) among newborn infants is limited and often controversial. To investigate the associations between prenatal exposure to major POPs and thyroid hormone levels among newborn infants, both cord serum or maternal serum concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) were compared with five thyroid hormones in cord serum of newborn infants as well as TSH in bloodspot collected at 2 day after birth (n=104). Since cord serum thyroid hormones could be affected by those of mothers, thyroid hormone concentrations of the matching mothers at delivery were adjusted. In cord serum, BDE-47, -99, and Σchlordane (CHD) showed significant positive associations with cord or bloodspot TSH. At the same time, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlorbenzene (HCB) showed negative associations with total T3 and total T4 in cord serum, respectively. Maternal exposure to β-hexachlorhexane (β-HCH), ΣCHD, ΣDDT, or p,p'-DDE were also associated with neonatal thyroid hormones. Although the sample size is small and the thyroid hormone levels of the subjects were within the reference range, our observation supports thyroid disrupting potential of several POPs among newborn infants, at the levels occurring in the general population. Considering the importance of thyroid hormones during gestation and early life stages, health implication of thyroid hormone effects by low level POPs exposure deserves further follow up investigations.
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Omidbakhsh R, Rajabli B, Nasoohi S, Khallaghi B, Mohamed Z, Naidu M, Ahmadiani A, Dargahi L. Fingolimod affects gene expression profile associated with LPS-induced memory impairment. Exp Brain Res 2014; 232:3687-96. [DOI: 10.1007/s00221-014-4052-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Accepted: 07/21/2014] [Indexed: 11/30/2022]
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León-Olea M, Martyniuk CJ, Orlando EF, Ottinger MA, Rosenfeld C, Wolstenholme J, Trudeau VL. Current concepts in neuroendocrine disruption. Gen Comp Endocrinol 2014; 203:158-173. [PMID: 24530523 PMCID: PMC4133337 DOI: 10.1016/j.ygcen.2014.02.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 02/01/2014] [Accepted: 02/04/2014] [Indexed: 11/17/2022]
Abstract
In the last few years, it has become clear that a wide variety of environmental contaminants have specific effects on neuroendocrine systems in fish, amphibians, birds and mammals. While it is beyond the scope of this review to provide a comprehensive examination of all of these neuroendocrine disruptors, we will focus on select representative examples. Organochlorine pesticides bioaccumulate in neuroendocrine areas of the brain that directly regulate GnRH neurons, thereby altering the expression of genes downstream of GnRH signaling. Organochlorine pesticides can also agonize or antagonize hormone receptors, adversely affecting crosstalk between neurotransmitter systems. The impacts of polychlorinated biphenyls are varied and in many cases subtle. This is particularly true for neuroedocrine and behavioral effects of exposure. These effects impact sexual differentiation of the hypothalamic-pituitary-gonadal axis, and other neuroendocrine systems regulating the thyroid, metabolic, and stress axes and their physiological responses. Weakly estrogenic and anti-androgenic pollutants such as bisphenol A, phthalates, phytochemicals, and the fungicide vinclozolin can lead to severe and widespread neuroendocrine disruptions in discrete brain regions, including the hippocampus, amygdala, and hypothalamus, resulting in behavioral changes in a wide range of species. Behavioral features that have been shown to be affected by one or more these chemicals include cognitive deficits, heightened anxiety or anxiety-like, sociosexual, locomotor, and appetitive behaviors. Neuroactive pharmaceuticals are now widely detected in aquatic environments and water supplies through the release of wastewater treatment plant effluents. The antidepressant fluoxetine is one such pharmaceutical neuroendocrine disruptor. Fluoxetine is a selective serotonin reuptake inhibitor that can affect multiple neuroendocrine pathways and behavioral circuits, including disruptive effects on reproduction and feeding in fish. There is growing evidence for the association between environmental contaminant exposures and diseases with strong neuroendocrine components, for example decreased fecundity, neurodegeneration, and cardiac disease. It is critical to consider the timing of exposures of neuroendocrine disruptors because embryonic stages of central nervous system development are exquisitely sensitive to adverse effects. There is also evidence for epigenetic and transgenerational neuroendocrine disrupting effects of some pollutants. We must now consider the impacts of neuroendocrine disruptors on reproduction, development, growth and behaviors, and the population consequences for evolutionary change in an increasingly contaminated world. This review examines the evidence to date that various so-called neuroendocrine disruptors can induce such effects often at environmentally-relevant concentrations.
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Affiliation(s)
- Martha León-Olea
- Departamento de Neuromorfología Funcional, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría, R.F.M., México D.F., México
| | - Christopher J. Martyniuk
- Canadian Rivers Institute and Department of Biology, University of New Brunswick, Saint John, New Brunswick, E2L 4L5, Canada
| | - Edward F. Orlando
- University of Maryland, Department of Animal and Avian Sciences, College Park, MD 20742, USA
| | - Mary Ann Ottinger
- University of Maryland, Department of Animal and Avian Sciences, College Park, MD 20742, USA
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204, USA
| | - Cheryl Rosenfeld
- Departments of Biomedical Sciences and Bond Life Sciences Center, Genetics Area Program, University of Missouri, Columbia, MO 65211, USA
| | - Jennifer Wolstenholme
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 23112, USA
| | - Vance L. Trudeau
- Department of Biology, University of Ottawa, 30 Marie Curie Private, Ottawa, ON, Canada, K1N 6N5
- Corresponding author:
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Guo Y, Zhou B. Thyroid endocrine system disruption by pentachlorophenol: an in vitro and in vivo assay. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 142-143:138-145. [PMID: 24001430 DOI: 10.1016/j.aquatox.2013.08.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/02/2013] [Accepted: 08/12/2013] [Indexed: 06/02/2023]
Abstract
The present study aimed to evaluate the disruption caused to the thyroid endocrine system by pentachlorophenol (PCP) using in vitro and in vivo assays. In the in vitro assay, rat pituitary GH3 cells were exposed to 0, 0.1, 0.3, and 1.0 μM PCP. PCP exposure significantly downregulated basal and triiodothyronine (T3)-induced Dio 1 transcription, indicating the antagonistic activity of PCP in vitro. In the in vivo assay, zebrafish embryos were exposed to 0, 1, 3, and 10 μg/L of PCP until 14 days post-fertilization. PCP exposure resulted in decreased thyroxine (T4) levels, but elevated contents of whole-body T3. PCP exposure significantly upregulated the mRNA expression of genes along hypothalamic-pituitary-thyroid (HPT) axis, including those encoding thyroid-stimulating hormone, sodium/iodide symporter, thyroglobulin, Dio 1 and Dio 2, alpha and beta thyroid hormone receptor, and uridinediphosphate-glucuronosyl-transferase. PCP exposure did not influence the transcription of the transthyretin (TTR) gene. The results indicate that PCP potentially disrupts the thyroid endocrine system both in vitro and in vivo.
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Affiliation(s)
- Yongyong Guo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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Boas M, Feldt-Rasmussen U, Main KM. Thyroid effects of endocrine disrupting chemicals. Mol Cell Endocrinol 2012; 355:240-8. [PMID: 21939731 DOI: 10.1016/j.mce.2011.09.005] [Citation(s) in RCA: 421] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 05/29/2011] [Accepted: 09/02/2011] [Indexed: 11/17/2022]
Abstract
In recent years, many studies of thyroid-disrupting effects of environmental chemicals have been published. Of special concern is the exposure of pregnant women and infants, as thyroid disruption of the developing organism may have deleterious effects on neurological outcome. Chemicals may exert thyroid effects through a variety of mechanisms of action, and some animal experiments and in vitro studies have focused on elucidating the mode of action of specific chemical compounds. Long-term human studies on effects of environmental chemicals on thyroid related outcomes such as growth and development are still lacking. The human exposure scenario with life long exposure to a vast mixture of chemicals in low doses and the large physiological variation in thyroid hormone levels between individuals render human studies very difficult. However, there is now reasonably firm evidence that PCBs have thyroid-disrupting effects, and there is emerging evidence that also phthalates, bisphenol A, brominated flame retardants and perfluorinated chemicals may have thyroid disrupting properties.
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Affiliation(s)
- Malene Boas
- Department of Growth and Reproduction GR, Rigshospitalet, University of Copenhagen, Denmark.
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Choi WK, Wirtshafter D, Park HJ, Lee MS, Her S, Shim I. The characteristics of supramammillary cells projecting to the hippocampus in stress response in the rat. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2012; 16:17-24. [PMID: 22416215 PMCID: PMC3298821 DOI: 10.4196/kjpp.2012.16.1.17] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 12/20/2011] [Accepted: 12/25/2011] [Indexed: 01/03/2023]
Abstract
The hypothalamus-pituitary-adrenocortex (HPA) axis is the central mediator of the stress response. The supramammillary (SuM) region is relatively unique among the hypothalamic structures in that it sends a large, direct projection to the hippocampal formation. It has been shown that mild stress could activate the SuM cells that project to the hippocampus. However, the role of these cell populations in modulating the stress response is not known. The present study examined the effect of stress on different populations of SuM cells that project to the hippocampus by injecting the fluorescent retrograde tracer, fluorogold (FG), into the hippocampus and utilizing the immunohistochemistry of choline acetyltransferase (ChAT), corticotrophin releasing factor (CRF), serotonin (5-HT), glutamate decarboxylase (GAD), tyrosine hydroxylase (TH) and NADPH-d reactivity. Immobilization (IMO) stress (2 hr) produced an increase in the expression of ChAT-immunoreactivity, and tended to increase in CRF, 5-HT, GAD, TH-immunoreactivity and nitric oxide (NO)-reactivity in the SuM cells. Fifty-three percent of 5-HT, 31% of ChAT and 56% of CRF cells were double stained with retrograde cells from the hippocampus. By contrast, a few retrogradely labeled cells projecting to the hippocampus were immunoreactive for dopamine, γ-aminobutyric acid (GABA) and NO. These results suggest that the SuM region contains distinct cell populations that differentially respond to stress. In addition, the findings suggest that serotonergic, cholinergic and corticotropin releasing cells projecting to the hippocampus within the SuM nucleus may play an important role in modulating stress-related behaviors.
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Affiliation(s)
- Woong Ki Choi
- Acupuncture & Meridian Science Research Center, College of Oriental Medicine, Kyung Hee University, Seoul 130-701, Korea
| | - David Wirtshafter
- Department of Psychology, The University of Illinois at Chicago, Chicago, IL 60607-7137, USA
| | - Hyun-Jung Park
- Acupuncture & Meridian Science Research Center, College of Oriental Medicine, Kyung Hee University, Seoul 130-701, Korea
- Department of Integrative Medicine and Research Center of Behavioral Medicine, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
| | - Mi-Sook Lee
- Acupuncture & Meridian Science Research Center, College of Oriental Medicine, Kyung Hee University, Seoul 130-701, Korea
- Division of Bio-Imaging, Chuncheon Center, Korea Basic Science Institute, Chuncheon 200-701, Korea
| | - Song Her
- Division of Bio-Imaging, Chuncheon Center, Korea Basic Science Institute, Chuncheon 200-701, Korea
| | - Insop Shim
- Acupuncture & Meridian Science Research Center, College of Oriental Medicine, Kyung Hee University, Seoul 130-701, Korea
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Hilgier W, Łazarewicz JW, Strużynska L, Frontczak-Baniewicz M, Albrecht J. Repeated exposure of adult rats to Aroclor 1254 induces neuronal injury and impairs the neurochemical manifestations of the NMDA receptor-mediated intracellular signaling in the hippocampus. Neurotoxicology 2011; 33:16-22. [PMID: 22044768 DOI: 10.1016/j.neuro.2011.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 10/17/2011] [Accepted: 10/17/2011] [Indexed: 11/30/2022]
Abstract
Aroclor 1254 is a mixture of polychlorinated biphenyls (PCBs), a class of environmental toxins which cause a wide spectrum of neurotoxic effects. Learning and memory deficits are the profound effects of PCBs which may be related to hippocampal dysfunction. To get insight into the underlying neurochemical mechanisms, we employed the microdialysis technique to investigate the effect of repeated exposure of adult male Wistar rats to Aroclor 1254 (10mg/kg b.w., daily, ig., for 14days), on the neurochemical parameters of NMDA receptor-mediated glutamatergic signaling in the hippocampus in vivo assessed using the microdialysis technique. The results demonstrated that exposure to Aroclor 1254, which was associated with substantial neuronal damage and loss in the hippocampus, markedly decreased the NMDA-induced extracellular accumulation of newly loaded (45)CaCl(2), cGMP and glutamate, and reduced the basal content of the NO precursor, arginine, indicating inhibition of the NMDA/NO/cGMP pathway. Aroclor 1254 exposure also decreased the basal microdialysate content of glutamate and glutamine, which may cause inadequate supply of the neurotransmitter glutamate, while the level of two other neuroactive amino acids, aspartate or taurine was not affected by the exposure. The results underscore neuronal lesion and inhibition of NMDA receptor-mediated glutamatergic signaling in hippocampus as a potential major contributor to the cognitive deficits associated with exposure to PCB.
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Affiliation(s)
- Wojciech Hilgier
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland
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Ahmed R. Perinatal TCDD exposure alters developmental neuroendocrine system. Food Chem Toxicol 2011; 49:1276-84. [DOI: 10.1016/j.fct.2011.03.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 02/26/2011] [Accepted: 03/09/2011] [Indexed: 10/18/2022]
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Rat pup social motivation: a critical component of early psychological development. Neurosci Biobehav Rev 2011; 35:1284-90. [PMID: 21251926 DOI: 10.1016/j.neubiorev.2011.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 01/07/2011] [Accepted: 01/11/2011] [Indexed: 11/23/2022]
Abstract
Examining the role of the offspring in early social dynamics is especially difficult. Human developmental psychology has found infant behavior to be a vital part of the early environmental setting. In the rodent model, the different ways that a rodent neonate or pup can influence social dynamics are not well known. Typically, litters of neonates or pups offer complex social interactions dominated by behavior seemingly initiated and maintained by the primary caregiver (e.g., the dam). Despite this strong role for the caregiver, the young most likely influence the litter dynamics in many powerful ways including communication signals, discrimination abilities and early approach behavior. Nelson and Panksepp (1996) developed a preference task to examine early rodent pup social motivation. We have used the same task to examine how variations in maternal care or different environmental perturbations could alter the rat pup preferences for social-related stimuli. Rat pups receiving low levels of maternal licking and grooming were impaired in maternal odor cue learning and emitted lower levels of 22kHz ultrasounds compared to pups from the high licking and grooming cohort. Prenatal stress or early exposure to a toxicant (polychlorinated biphenyl) altered early social preferences in the rat pup in different ways indicating that diverse strategies are expressed and specific to the type of perturbation exposure. A greater focus on the offspring motivation following early 'stressors' will allow for more complete understanding of the dynamics in behavior during early social development.
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Haave M, Bernhard A, Jellestad FK, Heegaard E, Brattelid T, Lundebye AK. Long-term effects of environmentally relevant doses of 2,2',4,4',5,5' hexachlorobiphenyl (PCB153) on neurobehavioural development, health and spontaneous behaviour in maternally exposed mice. Behav Brain Funct 2011; 7:3. [PMID: 21232145 PMCID: PMC3033814 DOI: 10.1186/1744-9081-7-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 01/13/2011] [Indexed: 11/27/2022] Open
Abstract
Background Polychlorinated biphenyls (PCBs) are widespread in the environment, human food and breast milk. Seafood is known to contain nutrients beneficial for the normal development and function of the brain, but also contaminants such as PCBs which are neurotoxic. Exposure to non-coplanar PCBs during brain development can disrupt spontaneous behaviour in mice and lead to hyperactive behaviour. Humans are chronically exposed to the highest relative levels of organochlorines in early childhood during brain development, though usually at doses which do not give clinical symptoms of toxicity. This study aimed to elucidate the developmental and behavioural effects of 2,2',4,4',5,5' hexachlorobiphenyl (PCB153) in mice, mimicking human exposure during gestation and lactation. Methods Environmentally relevant doses of PCB153 were added to the experimental diets. Feed concentrations were approximately 0.5, 6.5, and 1500 μg PCB153/kg feed, representing a realistic and a worst case scenario of frequent consumption of contaminated fish. The study also investigated the effects of maternal nutrition, i.e. a standard rodent diet versus a high inclusion of salmon. Mice pups were examined for physical- and reflex development, sensorimotor function and spontaneous behaviour from five days after birth until weaning. A selection of pups were followed until 16 weeks of age and tested for open field behaviour and the acoustic startle response (ASR) with prepulse inhibition (PPI). Blood thyroid hormones and liver enzymes, blood lipids and PCB153 content in fat were examined at 16 weeks. Statistical analyses modelled the three way interactions of diet, PCB exposure and litter size on behaviour, using generalized linear models (GLM) and linear mixed effect models (LME). The litter was used as a random variable. Non-parametric tests were used for pair wise comparisons of biochemical analyses. Results Litter size consistently influenced pup development and behaviour. Few lasting PCB153 related changes were observed, but results indicated effects on synchronization of physical development. Perinatal PCB153 exposure appeared to reduce habituation and cause aggression in males, though not statistically significant. Conclusions Litter size and maternal diet influenced physical development and function more than PCB153 in perinatally exposed mouse pups and supports the developmental importance of maternal care and the social environment.
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Affiliation(s)
- Marte Haave
- National Institute of Nutrition and Seafood Research (NIFES), Bergen, Norway.
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He P, Wang A, Niu Q, Guo L, Xia T, Chen X. Toxic effect of PBDE-47 on thyroid development, learning, and memory, and the interaction between PBDE-47 and PCB153 that enhances toxicity in rats. Toxicol Ind Health 2010; 27:279-88. [PMID: 20947653 DOI: 10.1177/0748233710387002] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are widespread environmental contaminants. There are potential interactive effects between PBDEs and PCBs, as these compounds share similar structures. The developmental neurotoxicity of 2, 2', 4, 4'-tetrabromodiphenyl ether (PBDE-47) and the interaction of PBDE-47 with 2, 2', 4, 4', 5, 5'-hexachlorobipheny (PCB153) were investigated herein, as the dominant congener forms of PBDEs and PCBs, respectively. SD rats were exposed to a single oral dose of PBDE-47 (1, 5, and 10 μg/g) and/or PCB153 (5 μg/g) on post-natal day (PND) 10. Concentrations of PBDE-47, triiodothyronine (T(3)), thyroxine (T(4)), and thyroid-stimulating hormone (TSH) in serum; organ-to-body weight ratios; as well as long-term learning and memory were measured in 2-month-old rats. The present study found that some doses of PBDE-47 decreased the organ-to-body weight ratios of the thyroid and uterus, decreased the concentration of T(4) in serum, and increased the organ-to-body weight ratio of the ovaries (p < 0.05). PCB153 could increase the action of PBDE-47 during combined exposure, but this interaction was not found between PBDE-47 and PCB153. In a Morris water maze experiment, the latency periods were significantly prolonged and time ratios were obviously depressed in all PBDE-47-treated groups compared to the control (p < 0.05); furthermore, significant interactions between PBDE-47 and PCB153 were observed (p < 0.05). In conclusion, PBDE-47 may depress thyroid development as well as the long-term learning and memory capabilities in adult rats exposed to PBDE-47 on PND 10. PCB153 can interact with PBDE-47, resulting in an increase in developmental neurotoxicity.
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Affiliation(s)
- Ping He
- Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hubei, People's Republic of China
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Jolous-Jamshidi B, Cromwell HC, McFarland AM, Meserve LA. Perinatal exposure to polychlorinated biphenyls alters social behaviors in rats. Toxicol Lett 2010; 199:136-43. [PMID: 20813172 DOI: 10.1016/j.toxlet.2010.08.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 08/23/2010] [Accepted: 08/24/2010] [Indexed: 01/25/2023]
Abstract
Perinatal exposure to polychlorinated biphenyls (PCBs) leads to significant alterations of neural and hormonal systems. These alterations have been shown to impair motor and sensory development. Less is known about the influence of PCB exposure on developing emotional and motivational systems involved in social interactions and social learning. The present study examined the impact of perinatal PCB exposure (mixture of congeners 47 and 77) on social recognition in juvenile animals, conspecific-directed investigation in adults and on neural and hormonal systems involved in social functions. We used a standard habituation-dishabituation paradigm to evaluate juvenile recognition and a social port paradigm to monitor adult social investigation. Areal measures of the periventricular nucleus (PVN) of the hypothalamus were obtained to provide correlations with related hormone and brain systems. PCB exposed rats were significantly impaired in social recognition as indicated by persistent conspecific-directed exploration by juvenile animals regardless of social experience. As adults, PCB exposure led to a dampening of the isolation-induced enhancement of social investigation. There was not a concomitant alteration of social investigation in pair-housed PCB exposed animals at this stage of development. Interestingly, PVN area was significantly decreased in juvenile animals exposed to PCB during the perinatal period. Shifts in hypothalamic regulation of hormones involved in social behavior and stress could be involved in the behavioral changes observed. Overall, the results suggest that PCB exposure impairs context or experience-dependent modulation of social approach and investigation. These types of social-context deficits are similar to behavioral deficits observed in social disorders such as autism and other pervasive developmental disorders.
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Affiliation(s)
- Banafsheh Jolous-Jamshidi
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403-0208, USA
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Liu D, Teng W, Shan Z, Yu X, Gao Y, Wang S, Fan C, Wang H, Zhang H. The effect of maternal subclinical hypothyroidism during pregnancy on brain development in rat offspring. Thyroid 2010; 20:909-15. [PMID: 20615128 DOI: 10.1089/thy.2009.0036] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Maternal thyroid hormones (THs), especially thyroxine (T(4)), are crucial to early brain development in the mammalian embryo. Epidemiological studies and case reports have shown that maternal subclinical hypothyroidism may result in significant negative effects on pregnancy and neurodevelopment of the fetus. To understand the mechanism responsible for these neurological alterations, we induced maternal subclinical hypothyroidism in pregnant rats. Behavior and several genes that are under the control of THs were evaluated in the offspring of TH-deficient rats. METHODS A total of 60 female rats were divided into three groups: (i) maternal subclinical hypothyroidism (total thyroidectomy with T(4) infusion), (ii) maternal hypothyroidism (total thyroidectomy without T(4) infusion), and (iii) control (sham operated). All rats were mated 10 days after the start of infusion. The infusion continued until 10 days postpartum. Pups were sacrificed at postnatal day 3 (PND 3), PND 7, and PND 21. The hippocampus was collected and tested for brain-derived neurotrophic factor (BDNF) and Rap1 protein expression by Western blotting and for BDNF and neural cell adhesion molecule mRNA expression by real-time polymerase chain reaction. On PND 41-PND 49, rat pups explored the Morris water maze. Time spent in the quadrant previously containing the platform was recorded. RESULTS This study found decreases in BDNF mRNA expression (on PND 3) and protein level (on PND 3 and PND 7) in hippocampi of pups from subclinical hypothyroidism dams (p < 0.05). Rap1 protein expression was higher in maternal subclinical hypothyroidism offspring than in control offspring at PND 7 and PND 21. No change was observed in neural cell adhesion molecule mRNA expression in the maternal subclinical hypothyroidism offspring. In addition, results from the Morris water maze revealed that pups from the subclinical hypothyroidism dams showed deficits in long-term memory, spending less time in the platform quadrant (p < 0.05) during testing. There was a trend toward a deficit in short-term memory (p > 0.05) in this group as well. CONCLUSIONS The long-term memory deficits of pups born to maternal subclinical hypothyroidism dams likely related with decreasing in BDNF mRNA expression and protein level as well as increasing in Rap1 protein expression in hippocampi.
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Affiliation(s)
- Dijie Liu
- The Institute of Endocrinology, The First Affiliated Hospital, China Medical University , Shenyang, People's Republic of China
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Jugan ML, Levi Y, Blondeau JP. Endocrine disruptors and thyroid hormone physiology. Biochem Pharmacol 2009; 79:939-47. [PMID: 19913515 DOI: 10.1016/j.bcp.2009.11.006] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 10/25/2009] [Accepted: 11/03/2009] [Indexed: 02/07/2023]
Abstract
Endocrine disruptors are man-made chemicals that can disrupt the synthesis, circulating levels, and peripheral action of hormones. The disruption of sex hormones was subject of intensive research, but thyroid hormone synthesis and signaling are now also recognized as important targets of endocrine disruptors. The neurological development of mammals is largely dependent on normal thyroid hormone homeostasis, and it is likely to be particularly sensitive to disruption of the thyroid axis. Here, we survey the main thyroid-disrupting chemicals, such as polychlorinated biphenyls, perchlorates, and brominated flame-retardants, that are characteristic disruptors of thyroid hormone homeostasis, and look at their suspected relationships to impaired development of the human central nervous system. The review then focuses on disrupting mechanisms known to be directly or indirectly related to the transcriptional activity of the thyroid hormone receptors.
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Affiliation(s)
- Mary-Line Jugan
- Univ Paris-Sud 11, Faculté de Pharmacie, Laboratoire Santé Publique-Environnement, 92290 Châtenay-Malabry, France.
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Abstract
PURPOSE OF REVIEW To overview the effects of endocrine disrupters on thyroid function. RECENT FINDINGS Studies in recent years have revealed thyroid-disrupting properties of many environmentally abundant chemicals. Of special concern is the exposure of pregnant women and infants, as thyroid disruption of the developing fetus may have deleterious effects on neurological outcome. Evidence is reviewed for the following groups of chemicals: polychlorinated biphenyls, dioxins, flame retardants, pesticides, perfluorinated chemicals, phthalates, bisphenol A and ultraviolet filters. Chemicals may exert thyroid effects through a variety of mechanisms of action, and some publications have focused on elucidating the mechanisms of specific (groups of) chemicals. SUMMARY A large variety of ubiquitous chemicals have been shown to have thyroid-disrupting properties, and the combination of mechanistic, epidemiological and exposure studies indicates that the ubiquitous human and environmental exposure to industrial chemicals may impose a serious threat to human and wildlife thyroid homeostasis. Currently, available evidence suggests that authorities need to regulate exposure to thyroid-disrupting chemicals of pregnant women, neonates and small children in order to avoid potential impairment of brain development. Future studies will indicate whether adults also are at risk of thyroid damage due to these chemicals.
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Affiliation(s)
- Malene Boas
- University Department of Growth and Reproduction, Rigshospitalet, Copenhagen, Denmark
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Cheng J, Yang Y, Ma J, Wang W, Liu X, Sakamoto M, Qu Y, Shi W. Assessing noxious effects of dietary exposure to methylmercury, PCBs and Se coexisting in environmentally contaminated rice in male mice. ENVIRONMENT INTERNATIONAL 2009; 35:619-625. [PMID: 19167073 DOI: 10.1016/j.envint.2008.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2008] [Revised: 11/16/2008] [Accepted: 12/13/2008] [Indexed: 05/27/2023]
Abstract
Polychlorinated biphenyls and methylmercury are two of the most ubiquitous environmental contaminants in Guizhou province. Rice is eaten with almost every meal and provides more calories than any single food in Guizhou province. The estimated tolerable daily intake of total mercury, MeHg, Se and PCBs from Guizhou contaminated rice by Chinese people showed that MeHg and/or PCBs exceeded the corresponding limits. The aim of this study was to characterize the effects of exposure to environmental contaminated rice on neurobehavioral development and neurobiological disruptions in mice. Animals were treated from postnatal day (PND) 22 to 91. At PND 26-91 days of age, mice were tested for neurobehavioural development and neurochemical level changes. We showed that dietary exposure to environmentally contaminated rice gave rise to different changes in antioxidants. Reduced superoxide dismutase (SOD) activity and excess increased nitric oxide (NO) indicated aggravation of oxidative status after long-term dietary intake of Hg and PCBs. Neurobehavioral derangement in the central nervous system and significant delay in the Morris water maze test response on PND 91 are correlated with the increased of c-fos/c-jun expression levels in the cerebral cortex. These results suggest that MeHg neurotoxicity might be a greater hazard than that associated with PCB, but PCB may augment the neurobehavioral deficits caused by increased levels of mercury exposure. The simultaneous intake of selenium might have a protective effect on Hg accumulation in the body, and vitamin C might protect mice against the toxic effects of PCBs. However, the protective role of Se and vitamin C is very limited for multiple-agent pollution. Immediately early genes in the brain response to contaminated rice might be dependent on interaction among NO, NO synthase (NOS), SOD and reduced glutathione (GSH). We should be alert to mental health problems in human beings when any kind of Hg- and PCB-polluted food is consumed.
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Affiliation(s)
- Jinping Cheng
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
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Developmental exposure to polychlorinated biphenyls or methylmercury, but not to its combination, impairs the glutamate-nitric oxide-cyclic GMP pathway and learning in 3-month-old rats. Neuroscience 2008; 154:1408-16. [PMID: 18556134 DOI: 10.1016/j.neuroscience.2008.05.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 05/12/2008] [Accepted: 05/13/2008] [Indexed: 11/21/2022]
Abstract
Prenatal exposure to polychlorinated biphenyls (PCBs) or methylmercury (MeHg) contaminated food may affect brain development, leading to long-term alterations in cognitive function. Both types of contaminants, PCBs and MeHg, are often found together contaminating food, especially fish in some polluted areas. Exposure to combinations of neurotoxicants may exert different effects on the developing nervous system than exposure to individual contaminants. Developmental exposure (during pregnancy and lactation) to PCB126 or PCB153 impairs learning ability when the rats are 3 months old. Impairment of learning seems to be a consequence of impairment of the function of the glutamate-nitric oxide (NO)-cGMP pathway in brain in vivo. The aims of the present work were 1) to assess whether perinatal exposure to MeHg also affects the function of the glutamate-NO-cGMP pathway in brain in vivo analyzed by in vivo brain microdialysis and/or the ability to learn the Y maze task when the rats are 3 months old, and 2) to assess whether perinatal exposure to combinations of MeHg with PCB153 or PCB126 potentiates, decreases or does not modify the effects of the individual neurotoxicants. Perinatal exposure to PCB126, PCB153 or MeHg impaired the function of the glutamate-NO-cGMP pathway in cerebellum and learning ability. However, co-exposure to PCB126+MeHg or PCB153+MeHg inhibits the impairment of the pathway or learning ability. These results support that the function of this pathway modulates learning of the Y maze task. Moreover, they show that co-exposure to these PCBs and MeHg does not exacerbate, but reduces the effects on the ability to learn this task.
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Steinberg RM, Walker DM, Juenger TE, Woller MJ, Gore AC. Effects of perinatal polychlorinated biphenyls on adult female rat reproduction: development, reproductive physiology, and second generational effects. Biol Reprod 2008; 78:1091-101. [PMID: 18305224 DOI: 10.1095/biolreprod.107.067249] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Perinatal exposures to endocrine-disrupting chemicals, such as polychlorinated biphenyls (PCBs), can cause latent effects on reproductive function. Here, we tested whether PCBs administered during late pregnancy would compromise reproductive physiology in both the fetally exposed female offspring (F1 generation), as well as in their female offspring (F2 generation). Pregnant Sprague-Dawley rats were treated with the PCB mixture, Aroclor 1221 (A1221; 0, 0.1, 1, or 10 mg/kg), on Embryonic Days 16 and 18. Somatic and reproductive development of F1 and their F2 female offspring were monitored, including ages of eye opening, pubertal landmarks, and serum reproductive hormones. The results showed that low doses of A1221 given during this critical period of neuroendocrine development caused differential effects of A1221 on F1 and F2 female rats. In both generations, litter sex ratio was skewed toward females. In the F1 generation, additional effects were found, including a significant alteration of serum LH in the 1 mg/kg A1221 group. The F2 generation showed more profound alterations, particularly with respect to fluctuations in hormones and reproductive tract tissues across the estrous cycle. On proestrus, the day of the preovulatory GnRH/gonadotropin surge, F2 females whose mothers had been exposed perinatally to A1221 exhibited substantially suppressed LH and progesterone concentrations, and correspondingly smaller uterine and ovarian weights on estrus, compared with F2 descendants of control rats. These latter changes suggest a dysregulation of reproductive physiology. Thus, low levels of exposure to PCBs during late fetal development cause significant effects on the maturation and physiology of two generations of female offspring. These findings have implications for reproductive health and fertility of wildlife and humans.
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Affiliation(s)
- Rebecca M Steinberg
- The Institute for Neuroscience, The University of Texas at Austin, Austin, Texas 78712, USA
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Gutleb AC, Schriks M, Mossink L, Berg JHJVD, Murk AJ. A synchronized amphibian metamorphosis assay as an improved tool to detect thyroid hormone disturbance by endocrine disruptors and apolar sediment extracts. CHEMOSPHERE 2007; 70:93-100. [PMID: 17681587 DOI: 10.1016/j.chemosphere.2007.06.048] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Revised: 05/21/2007] [Accepted: 06/20/2007] [Indexed: 05/16/2023]
Abstract
Amphibian metamorphosis assays are used to evaluate potential effects of endocrine disrupting compounds on the thyroid hormone axis. In this study, Xenopus laevis tadpoles are kept in a solution of 0.2% thiourea (TU) to arrest and synchronise them in their development. The advantage of this synchronized amphibian metamorphosis assays is that synchronised tadpoles are available at any time to start metamorphosis experiments, and experimental groups are much more homogenous at the start of experimental exposure compared with groups selected from an untreated pool of animals. The water volume per animal was kept constant throughout the experimental period to overcome the influence of declining numbers of animals per aquarium due to metamorphosis and mortality on the density dependent development of the remaining tadpoles. Clophen A50 (a technical PCB mixture), the single congener 3,3',4,4'-tetrachlorobiphenyl (PCB 77) and apolar sediment extracts that were previously tested positive in the T-Screen, an in vitro proliferation assay for thyroid hormone disruption, were tested in the Synchronized Amphibian Metamorphosis Assay. Endpoints studied were mortality, malformations, body weight, and percentage of metamorphosed froglets at the end of the 60-day experimental period, percentage of tadpoles in different developmental stages, and developmental stage-dependent awarded penalty points. Dietary exposure to Clophen A50 (0.2-50mg/kg food) resulted in a significant increased percentage of tadpoles that did not pass metamorphosis at concentrations higher than 2mg/kg food. Time until metamorphosis in those animals that were able to metamorphose after the 60-days experimental period was significantly decreased. Dietary exposure to PCB 77, a congener that can be readily metabolised, did not result in significant effects in any exposure group (2-500 microg/kg food). Apolar sediment extracts from two of the three sites that are contaminated with a wide variety of chemicals significantly decreased the percentage of metamorphosed animals and significantly increased the number of tadpoles that remained in early and late metamorphic stages. These effects already occurred when the extracts where diluted more than 1000 times (on an organic carbon base) compared to environmental concentrations. The rank of potency was comparable to results obtained with the T-screen. This suggests the presence of thyroid hormone disrupting compounds in the aquatic environment and possible effects of such compounds on animal development in the wild.
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Affiliation(s)
- Arno C Gutleb
- Toxicology Section, Wageningen University, Tuinlaan 5, Wageningen, The Netherlands
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Coccini T, Roda E, Castoldi AF, Goldoni M, Poli D, Bernocchi G, Manzo L. Perinatal co-exposure to methylmercury and PCB153 or PCB126 in rats alters the cerebral cholinergic muscarinic receptors at weaning and puberty. Toxicology 2007; 238:34-48. [PMID: 17618726 DOI: 10.1016/j.tox.2007.05.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Revised: 05/10/2007] [Accepted: 05/14/2007] [Indexed: 10/23/2022]
Abstract
In the last few decades, combined exposure to methylmercury (MeHg) and polychlorinated biphenyls (PCBs) from fish and seafood, and their potentially interactive effects on neurodevelopment, have been giving increasing cause for concern. We examined the combined effects of MeHg and either a non-dioxin PCB (PCB153) or a dioxin-like PCB (PCB126) congener on the developing brain cholinergic muscarinic receptors (MRs). These receptors are known to play a major role in many central functions including higher cognitive processes and the modulation of extrapyramidal motor activity. MRs in pup rat brains diminished following prenatal and lactational exposure, from gestational day [GD]7 to postnatal day [PND]21, to MeHg (0.5mg/kgbodyweight[bw]/day), PCB153 (5mg/kgbw/day), and PCB126 (100ng/kg/day), alone or in combination. Total MR density, as well as M1, M2, and M3 receptor subtypes of the weanling and pubertal rats, were affected in a brain-area-, gender-, time- and compound-dependent fashion. MeHg decreased (by 15-20%) the total MR density in a delayed (PND36) manner in the cerebral cortex of both genders, and early (at weaning) in the cerebellum of both genders, with the effect lasting until puberty (in males only). MeHg decreased the ACh M1- and M3-immunopositive neurons in the cerebral cortex and also increased the M2-immunopositive Bergmann glia in the cerebellum. PCB153 also induced a delayed (PND36) decrease (of 20%) in total MR number in the cerebellum of the male offspring and in the cerebral cortex of both genders. The latter effect was coupled with a decrease in ACh M1- and ACh M3-immunopositive neuron populations. PCB126 decreased (by 30-40%) total MR density in a gender-dependent manner, males being more sensitive than females. The effect was evident early (at PND21) and lasted until puberty in the cerebellum, while it was observed later (at PND36) in the cerebral cortex. The M1 and M3 receptors were similarly affected by PCB126. Co-exposure to MeHg and either PCB153 or PCB126 had the same effect on the cerebral MRs as exposure to each compound alone. The results rule out additive or synergistic interactions between MeHg and PCB153 or PCB126 on MRs in the brain areas examined. Some early-onset changes persisted until puberty, while other modifications became manifest only at the advanced time point (PND36), when the brain levels of total Hg, PCB153, and PCB126 had declined. These data support the ability of MeHg and PCBs to induce delayed neurotoxicity after developmental exposure.
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Affiliation(s)
- Teresa Coccini
- IRCCS Salvatore Maugeri Foundation, Toxicology Division, Institute of Pavia, Italy.
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Gutleb AC, Mossink L, Schriks M, van den Berg HJH, Murk AJ. Delayed effects of environmentally relevant concentrations of 3,3',4,4'-tetrachlorobiphenyl (PCB-77) and non-polar sediment extracts detected in the prolonged-FETAX. THE SCIENCE OF THE TOTAL ENVIRONMENT 2007; 381:307-15. [PMID: 17451789 DOI: 10.1016/j.scitotenv.2007.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 02/02/2007] [Accepted: 03/01/2007] [Indexed: 05/15/2023]
Abstract
In the prolonged-FETAX (prolonged-Frog Embryo Teratogenic Assay-Xenopus) tadpoles are allowed to develop until metamorphosis after an initial 4 day early life-stage exposure (FETAX). PCB 77 (3,4,3',4'-tetrachlorobiphenyl) and sediment extracts were used in the presented experiments. Concentrations of PCB 77 (0.03 nM=8.55 ng/L; 3 nM=855 ng/L; 300 nM=85.5 microg/L, 30,000 nM=8.55 mg/L) were derived on the basis of dioxin-like toxic equivalency concentrations known to be present in pore-water. The results were compared to those obtained with the standard FETAX. In the prolonged-FETAX the percentage of animals passing metamorphosis within 115 days was significantly decreased in the groups exposed to 300 or 30,000 nM PCB 77. Significantly increased percentages of tadpoles were halted in thyroid hormone dependent early metamorphic NF stages <or=55 (3 nM PCB 77) and metamorphic stages 56-60 tadpoles (300 nM PCB 77 and 30,000 nM PCB 77). Non-polar sediment extracts from two contaminated Dutch sites significantly decreased, and one significantly increased the percentage of animals that passed metamorphosis. These results were in accordance with earlier in vitro results in a thyroid hormone dependent assay and strongly suggest the presence of thyroid hormone disrupting compounds in the aquatic environment. In the classical FETAX neither PCB 77 nor non-polar sediment extracts induced any effects. The results of the present study indicate that the prolonged-FETAX is an important in vivo tool in addition to the in vitro T-screen to assess long-term effects of early life-stage exposure to environmentally relevant concentrations of (mixtures of) compounds and that affect thyroid hormone dependent physiology.
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Affiliation(s)
- Arno C Gutleb
- Toxicology Section, Wageningen University, Tuinlaan 5 NL-6703 HE Wageningen, The Netherlands.
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Miyagawa K, Narita M, Narita M, Akama H, Suzuki T. Memory impairment associated with a dysfunction of the hippocampal cholinergic system induced by prenatal and neonatal exposures to bisphenol-A. Neurosci Lett 2007; 418:236-41. [PMID: 17467901 DOI: 10.1016/j.neulet.2007.01.088] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 01/15/2007] [Accepted: 01/28/2007] [Indexed: 11/26/2022]
Abstract
One of the most common chemicals that behaves as an endocrine disruptor is the compound 4,4'-isopronylidenediphenol, called bisphenol-A. In the previous study, we reported that exposure to bisphenol-A induced the abnormality of dopamine receptor functions in the mouse limbic area, resulting in a supersensitivity of drugs of abuse-induced pharmacological actions. The present study was undertaken to investigate whether prenatal and neonatal exposures to bisphenol-A could alter other behavioral abnormalities such as anxiogenic behavior, motor learning behavior, or memory. In the present study, adult female mice were chronically treated with bisphenol-A-admixed powder food from mating to weaning. All experiments were performed using male pups. Here we found that prenatal and neonatal exposures to bisphenol-A failed to induce anxiogenic effects and motor-learning impairment using the light-dark test, elevated plus maze test, and rota-rod test. On the other hand, we found that prenatal and neonatal exposures to bisphenol-A induced the memory impairment using the step-through passive avoidance test. Immunohistochemical study showed the dramatic reduction in choline acetyltransferase-like immunoreactivity, which is a marker of acetylcholine (ACh) production, in the hippocampus of mice prenatally and neonatally exposed to bisphenol-A. These results suggest that chronic exposures to bisphenol-A could induce the memory impairment associated with the reduction in ACh production in the hippocampus.
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Affiliation(s)
- Kazuya Miyagawa
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawaku, Tokyo 142-8501, Japan
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Cromwell HC, Johnson A, McKnight L, Horinek M, Asbrock C, Burt S, Jolous-Jamshidi B, Meserve LA. Effects of polychlorinated biphenyls on maternal odor conditioning in rat pups. Physiol Behav 2007; 91:658-66. [PMID: 17498760 PMCID: PMC4138982 DOI: 10.1016/j.physbeh.2007.03.029] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2006] [Revised: 01/23/2007] [Accepted: 03/27/2007] [Indexed: 11/29/2022]
Abstract
Polychlorinated biphenyls (PCBs) are pervasive environmental contaminants that can have damaging effects on physiologic, motoric and cognitive function. Results from studies on PCBs and behavior have shown that exposure can alter learning and memory processes and that these shifts in cognitive abilities can be related to changes in hormonal and neural function. Little experimentation has been done on the impact of exposure to PCBs on social and emotional development. Previous work has shown that exposure to PCBs in children can alter play behavior. Importantly, exposure to PCBs has been found to change aspects of maternal-offspring interactions in rodents. The present study examined the impact of PCBs on maternal odor conditioning in rat pups 12-14 days of age. A modified version of the conditioned place preference paradigm was used that incorporated a maternal-associated odor cue (lemon scent) as the conditioned stimulus. PCBs significantly depressed the preference for the maternal-associated cue but did not impair discrimination for a novel odor. These effects could arise due to changes in the social dynamics between the dam and offspring after co-exposure to PCBs. For example, dams exposed to PCBs during gestation have been found to show elevated grooming directed towards pups exposed to PCBs. This change in maternal care can have dramatic effects on behavioral and hormonal systems in the developing rat pup. In conclusion, perinatal PCBs alter important social behaviors of both the mother and pup, and these alterations could have long-lasting effects on behavioral, cognitive and emotional development.
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Affiliation(s)
- Howard C Cromwell
- Department of Psychology, Bowling Green State University, Bowling Green, OH 43403, USA.
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29
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Lehigh Shirey EA, Jelaso Langerveld A, Mihalko D, Ide CF. Polychlorinated biphenyl exposure delays metamorphosis and alters thyroid hormone system gene expression in developing Xenopus laevis. ENVIRONMENTAL RESEARCH 2006; 102:205-14. [PMID: 16720020 DOI: 10.1016/j.envres.2006.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Revised: 03/29/2006] [Accepted: 04/03/2006] [Indexed: 05/09/2023]
Abstract
Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants that disrupt thyroid hormone (TH) system function in numerous species. Previous studies have shown delayed metamorphosis in developing Xenopus laevis frogs exposed to PCBs, but the underlying molecular mechanisms have not been thoroughly investigated. In this research, developing X. laevis tadpoles were exposed to environmentally relevant concentrations (5, 50ppb) of Aroclor 1254 (A1254), a PCB mixture, dissolved in water and 0.25% dimethyl sulfoxide. Quantitative real-time reverse transcriptase polymerase chain reaction was used to measure expression of several TH system genes, other genes that regulate growth and development, and a xenobiotic response gene. Exposure to 50ppb A1254 significantly delayed metamorphosis and significantly altered gene expression of three thyroid system genes: transthyretin and types II and III deiodinase. Since all three genes regulate the amount of available, biologically active TH, PCB-induced changes in the expression of these genes may underlie alterations in metamorphic timing.
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Mariussen E, Fonnum F. Neurochemical targets and behavioral effects of organohalogen compounds: an update. Crit Rev Toxicol 2006; 36:253-89. [PMID: 16686424 DOI: 10.1080/10408440500534164] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Organohalogen compounds (OHCs) have been used and still are used extensively as pesticides, flame retardants, hydraulic fluids, and in other industrial applications. These compounds are stable, most often lipophilic, and may therefore easily biomagnify. Today these compounds are found distributed both in human tissue, including breast milk, and in wildlife animals. In the late 1960s and early 1970s, high levels of the polychlorinated biphenyls (PCBs) and the pesticide dichlorodiphenyl trichloroethane (DDT) were detected in the environment. In the 1970s it was discovered that PCBs and some chlorinated pesticides, such as lindane, have neurotoxic potentials after both acute and chronic exposure. Although the use of PCBs, DDT, and other halogenated pesticides has been reduced, and environmental levels of these compounds are slowly diminishing, other halogenated compounds with potential of toxic effects are being found in the environment. These include the brominated flame retardants, chlorinated paraffins (PCAs), and perfluorinated compounds, whose levels are increasing. It is now established that several OHCs have neurobehavioral effects, indicating adverse effects on the central nervous system (CNS). For instance, several reports have shown that OHCs alter neurotransmitter functions in CNS and Ca2+ homeostatic processes, induce protein kinase C (PKC) and phospholipase A2 (PLA2) mobilization, and induce oxidative stress. In this review we summarize the findings of the neurobehavioral and neurochemical effects of some of the major OHCs with our main focus on the PCBs. Further, we try to elucidate, on the basis of available literature, the possible implications of these findings on human health.
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Affiliation(s)
- E Mariussen
- Norwegian Institute for Air Research, Kjeller, Norway.
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31
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Basu N, Kwan M, Chan HM. Mercury but not organochlorines inhibits muscarinic cholinergic receptor binding in the cerebrum of ringed seals (Phoca hispida). JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2006; 69:1133-43. [PMID: 16728376 DOI: 10.1080/15287390500362394] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Elevated concentrations of organochlorines and mercury (Hg) have been reported in marine mammals on a global scale. While risk assessments are generally based on quantifying body burdens of toxicants, much less is known about associated adverse health effects and their underlying mechanisms. The purpose of this study was to characterize the inhibitory effects of methylmercury (MeHg+), mercuric chloride (Hg2+), p,p'-DDT, Arochlor 1254, chlordane,dieldrin, lindane, and toxaphene on [3H]quinuclidinyl benzilate ([3H]-QNB) binding to the muscarinic cholinergic (mACh) receptor in cellular membranes isolated from the cerebrum of ringed seals (Phoca hispida). [3H]-QNB binding to the mACh receptor was saturable with a mean receptor density (B(max)) of 826.9 +/- 68.4 fmol/mg and ligand affinity (K(d)) of 0.31 +/- 0.04 nM. MeHg+ and Hg2+ were the only neurotoxicants that inhibited radioligand binding by greater than 50%. Hg2+ was significantly more potent at inhibiting mACh receptor binding than MeHg+ when the IC50 data were compared (IC50 = 1.92 +/- 0.06 microM versus 2.75 +/- 0.22 microM), but when the data were normalized to derive inhibition constants (K(i)) there was no statistical difference in inhibition (Hg2+ = 1.38 +/- 0.07 mM; MeHg+ = 1.26 +/- 0.12 microM). Toxaphene also inhibited mACh receptor binding by 22.4%, but this was only significant at the highest concentration tested (320 microM). Overall, these data suggest that Hg, and not organochlorines,inhibits ligand binding to the mACh receptor. These mechanistic findings may be used to support and develop specific biomarkers of Hg exposure and neurotoxicity in sensitive ecological species.
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Affiliation(s)
- Niladri Basu
- Department of Natural Resource Sciences and Center for Indigenous Peoples' Nutrition and Environment (CINE), McGill University, Ste. Anne de Bellevue, Quebec
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Malkiewicz K, Mohammed R, Folkesson R, Winblad B, Szutowski M, Benedikz E. Polychlorinated biphenyls alter expression of α-synuclein, synaptophysin and parkin in the rat brain. Toxicol Lett 2006; 161:152-8. [PMID: 16174552 DOI: 10.1016/j.toxlet.2005.08.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 08/17/2005] [Accepted: 08/22/2005] [Indexed: 10/25/2022]
Abstract
Polychlorinated Biphenyls (PCBs)-induced changes in synaptic transmission are one of the effects of their neurotoxicity but the mechanism remains unknown. We assessed the in vivo effects of the PCBs mixture, Aroclor 1254 on the expression of neuronal proteins that are involved in the synaptic function and/or are associated with neurodegeneration. Wistar rats were treated orally with repeated doses of Aroclor 1254 and the levels of soluble alpha-synuclein, parkin, synaptophysin and amyloid precursor protein (APP) in the brain were determined by Western blotting. The results showed that Aroclor did not cause changes in the expression and processing of APP but at a dose 100 microg/g/day repeated for 6 days caused a decrease in the expression of alpha-synuclein in the cerebellum, cortex, hippocampus and hypothalamus of the animals sacrificed 2 days after treatment. The decrease in alpha-synuclein was accompanied by a transient increase in parkin and synaptophysin levels. Interestingly, in the hypothalamus the levels of alpha-synuclein remained decreased after 21 days post treatment perhaps due to regional differences in the PCBs elimination or perhaps a more specific interaction with the dopaminergic cells that are present in the hypothalamus that needs to be investigated further.
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Affiliation(s)
- Katarzyna Malkiewicz
- Karolinska Institutet, Neurotec, Section of Experimental Geriatrics, KFC, Novum, 141 86 Stockholm, Sweden.
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Takser L, Mergler D, Baldwin M, de Grosbois S, Smargiassi A, Lafond J. Thyroid hormones in pregnancy in relation to environmental exposure to organochlorine compounds and mercury. ENVIRONMENTAL HEALTH PERSPECTIVES 2005; 113:1039-45. [PMID: 16079076 PMCID: PMC1280346 DOI: 10.1289/ehp.7685] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Polychlorinated biphenyls (PCBs), chlorinated pesticides, and mercury are global environmental contaminants that can disrupt the endocrine system in animals and humans. However, there is little evidence that they can interfere with endocrine status in pregnant women and neonates at low levels of exposure. The aim of this study was to examine thyroid hormone levels during pregnancy and in cord blood in relation to blood concentrations of organochlorine compounds (OCs) and Hg in healthy women recruited during pregnancy. We found a significant negative correlation between maternal total triiodothyronine levels and three non-coplanar congeners (PCB-138, PCB-153, and PCB-180), three pesticides (p,p -DDE, cis-nanochlor, and hexachlorobenzene), and inorganic Hg independently, without any other changes in thyroid status. No significant relationships were observed between OCs and cord serum thyroid hormones. Cord serum free thyroxin was negatively correlated with inorganic Hg. These results suggest that at even low levels of exposure, persistent environmental contaminants can interfere with thyroid status during pregnancy.
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Affiliation(s)
- Larissa Takser
- Laboratoire de Physiologie Materno-foetale, Université du Quebec à Montréal, Montréal, Quebec, Canada
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