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Marsotto M, De Santis S, Sotgiu G, Battocchio C, Iucci G, Ceccucci A, Masci G, Orsini M. Multifunctional Platform for Covalent Titanium Coatings: Micro-FTIR, XPS, and NEXAFS Characterizations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:6837-6845. [PMID: 37130382 DOI: 10.1021/acs.langmuir.3c00424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
This work aims at preparing and characterizing a versatile multifunctional platform enabling the immobilization of macromolecules on a titanium surface by robust covalent grafting. Functionalized titanium is widely used in the biomedical field to improve its properties. Despite its high biocompatibility and osteointegrability, titanium implants are not very stable in the long term due to the onset of inflammation and bacterial infections. The proposed method allows the superficial insertion of three different organic linkers to be used as anchors for the attachment of biopolymers or bioactive molecules. This strategy used green solvents and is a good alternative to the proposed classic methods that employ organic solvents. The uniformly modified surfaces were characterized by micro-Fourier transform infrared spectroscopy (micro-FTIR), X-ray Photoelectron spectroscopy (XPS) and Near-Edge X-ray Absorption Fine Structure (NEXAFS). The latter made it possible to assess the orientation of the linker molecules with respect to the titanium surface. To test the efficiency of the linkers, two polymers (alginate and 2-(dimethylamino)-ethyl methacrylate (PDMAEMA)), with the potential ability to increase biocompatibility, were covalently attached to the titanium surfaces. The obtained results are a good starting point for the realization of stable polymeric coatings permanently bonded to the surface that could be used to extend the life of biomedical implants.
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Affiliation(s)
- Martina Marsotto
- Department of Science, Roma Tre University, Via della Vasca Navale 79, 00146 Rome, Italy
| | - Serena De Santis
- Department of Industrial, Electronic and Mechanical Engineering, Roma Tre University, Via Vito Volterra 62, 00146 Rome, Italy
| | - Giovanni Sotgiu
- Department of Industrial, Electronic and Mechanical Engineering, Roma Tre University, Via Vito Volterra 62, 00146 Rome, Italy
| | - Chiara Battocchio
- Department of Science, Roma Tre University, Via della Vasca Navale 79, 00146 Rome, Italy
| | - Giovanna Iucci
- Department of Science, Roma Tre University, Via della Vasca Navale 79, 00146 Rome, Italy
| | - Anita Ceccucci
- Department of Industrial, Electronic and Mechanical Engineering, Roma Tre University, Via Vito Volterra 62, 00146 Rome, Italy
| | - Giancarlo Masci
- Department of Chemistry, Sapienza University of Rome, P.le A. Moro 5, 00185 Roma, Italy
| | - Monica Orsini
- Department of Industrial, Electronic and Mechanical Engineering, Roma Tre University, Via Vito Volterra 62, 00146 Rome, Italy
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Davidson CJ, Svenson DW, Hannigan JH, Perrine SA, Bowen SE. A novel preclinical model of environment-like combined benzene, toluene, ethylbenzene, and xylenes (BTEX) exposure: Behavioral and neurochemical findings. Neurotoxicol Teratol 2022; 91:107076. [PMID: 35167944 DOI: 10.1016/j.ntt.2022.107076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 01/14/2022] [Accepted: 02/08/2022] [Indexed: 12/07/2022]
Abstract
Environmental exposure to toxicants is a major health issue and a leading risk factor for premature mortality worldwide, including environmental exposures to volatile organic compounds (VOCs), specifically Benzene, Toluene, Ethylbenzene, and Xylene (BTEX). While exposure to these compounds individually has shown behavioral and neurochemical effects, this investigation examined the impact of exposure to combined BTEX using a preclinical model. Male Swiss Webster mice were exposed to BTEX vapors designed to approximate environmental levels in urban communities. Animals were exposed to one of four treatment conditions: a 0-ppm (air control), two BTEX groups representing levels of environmental-like exposure, and a fourth group modeling occupational-like exposure. These exposures were conducted in 1.5-h sessions, 2 sessions/day, 5 days/week, for 3 weeks. Effects on coordination (i.e., rotarod and inverted screen test), learning and memory (i.e., Y-maze), and locomotor behavior (i.e., movement during exposure) were assessed during and after exposure. Monoamine levels in the medial prefrontal cortex and nucleus accumbens were assessed immediately following exposure. Effects of BTEX exposure were found on the variance of locomotor activity but not in other behavioral or neurochemical assessments. These results indicate that the combination of inhaled BTEX at environmentally representative concentrations has demonstrable, albeit subtle, effects on behavior.
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Affiliation(s)
| | - D W Svenson
- Department of Psychology, Wayne State University, Detroit, MI, USA
| | - John H Hannigan
- Department of Psychology, Wayne State University, Detroit, MI, USA; Department of Obstetrics & Gynecology, Wayne State University, Detroit, MI, USA; Merrill Palmer Skillman Institute for Child & Family Development, Wayne State University, Detroit, MI, USA; Center for Urban Responses to Environmental Stressors, Wayne State University, Detroit, MI, USA
| | - Shane A Perrine
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, MI, USA; John D. Dingell VA Medical Center, Detroit, MI, USA
| | - Scott E Bowen
- Department of Psychology, Wayne State University, Detroit, MI, USA; Center for Urban Responses to Environmental Stressors, Wayne State University, Detroit, MI, USA.
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Toluene Can Disrupt Rat Ovarian Follicullogenesis and Steroidogenesis and Induce Both Autophagy and Apoptosis. BIOLOGY 2021; 10:biology10111153. [PMID: 34827146 PMCID: PMC8615224 DOI: 10.3390/biology10111153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/01/2021] [Accepted: 11/04/2021] [Indexed: 11/17/2022]
Abstract
Toluene has been shown to be highly toxic to humans and animals and can cause damage to various tissues. However, studies reporting its effects on ovarian function are still limited. In this study, we investigated the in vivo effect of toluene using female Wistar rats. We found that toluene exposure decreased ovarian weight and affected ovarian structure by increasing the number of abnormally growing follicles. Moreover, it significantly increased progesterone and testosterone levels. We also showed that toluene exposure decreased GDF-9 protein and its encoding gene. In addition, it inhibited the expression of most of the genes involved in granulosa cell proliferation and differentiation, such as Insl3, ccnd2 and actb. The TUNEL assay showed that apoptosis occurred at the middle and high doses only (4000 and 8000 ppm, respectively), whereas no effect was observed at the low dose (2000 ppm). Interestingly, we showed that toluene exposure induced autophagy as LC3 protein and its encoding gene significantly increased for all doses of treatment. These results may suggest that the activation of autophagy at a low dose of exposure was to protect ovarian cells against death by inhibiting apoptosis, whereas its activation at high doses of exposure triggered apoptosis leading to cell death.
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Crossin R. Exploring the link between adolescent inhalant misuse and suicidal behaviour: a behavioural toxicology perspective. Neurotoxicol Teratol 2021; 88:107038. [PMID: 34678460 DOI: 10.1016/j.ntt.2021.107038] [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: 05/26/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 10/20/2022]
Abstract
Adolescent inhalant misuse has a known association with suicidal thoughts and behaviour. This association persists even after inhalant misuse has ceased. Previous studies have hypothesised that this association may derive from socioeconomic disadvantage or vulnerability, and potentially mediated by impulsivity. This association may also be due to the central nervous system depressant effects of inhalants. This review takes a behavioural toxicology perspective, focussed particularly on the serotonergic system and the Hypothalamic-Pituitary-Adrenal (HPA) axis, as potential links between adolescent inhalant misuse and suicidal behaviour. The challenges of bridging the pre-clinical and clinical literature in this area are discussed, along with promising avenues for future research; ultimately aimed at reducing suicide risk in a vulnerable adolescent population group.
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Affiliation(s)
- Rose Crossin
- Department of Population Health, University of Otago (Christchurch), Christchurch 8140, New Zealand.
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Davidson CJ, Hannigan JH, Bowen SE. Effects of inhaled combined Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX): Toward an environmental exposure model. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2021; 81:103518. [PMID: 33132182 DOI: 10.1016/j.etap.2020.103518] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 06/11/2023]
Abstract
Combined environmental exposures to the volatile organic compounds (VOCs) Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) pose clear risks to public health. Research into these risks is under-studied even as BTEX levels in the atmosphere are predicted to rise. This review focuses on the available literature using single- and combined-BTEX component inhaled solvent exposures in animal models, necessarily also drawing on findings from models of inhalant abuse and occupational exposures. Health effects of these exposures are discussed for multiple organ systems, but with particular attention on neurobehavioral outcomes such as locomotor activity, impulsivity, learning, and psychopharmacological responses. It is clear that animal models have significant differences in the concentrations, durations and patterns of exposure. Experimental evidence of the deleterious health and neurobehavioral consequences of exposures to the individual components of BTEX were found, but these effects were typically assessed using concentrations and exposure patterns not characteristic of environmental exposure. Future studies with animal models designed appropriately to explore combined BTEX will be necessary and advantageous to discovering health outcomes and more subtle neurobehavioral impacts of long-term environmental exposures.
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Affiliation(s)
| | - John H Hannigan
- Department of Psychology, Wayne State University, Detroit, MI, USA; Department of Obstetrics & Gynecology, Wayne State University, Detroit, MI, USA; Merrill Palmer Skillman Institute for Child & Family Development, Wayne State University, Detroit, MI, USA; Center for Urban Responses to Environmental Stressors, Wayne State University, Detroit, MI, USA
| | - Scott E Bowen
- Department of Psychology, Wayne State University, Detroit, MI, USA; Center for Urban Responses to Environmental Stressors, Wayne State University, Detroit, MI, USA.
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Crossin R, Arunogiri S. Harms associated with inhalant misuse in adolescent females - a review of the pre-clinical and clinical evidence. Drug Alcohol Depend 2020; 216:108232. [PMID: 32862119 DOI: 10.1016/j.drugalcdep.2020.108232] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 01/14/2023]
Abstract
BACKGROUND Inhalant misuse, or the misuse of products containing toluene is common in adolescents, and is associated with diverse physiological and psychological harms. Females comprise over half those who misuse inhalants in adolescence, however, the majority of the evidence has been derived from male-only or mixed-sex studies without exploration of sex differences. Female adolescence is a critical maturational period with potential for growth, reproductive, cognitive and psychological harms that may lead to long-term health consequences. We therefore summarise evidence of female-specific harms arising from inhalant misuse. METHODS We synthesised pre-clinical and clinical studies of inhalant misuse which were conducted in females, or where sex-differences were reported, into a narrative literature review. RESULTS Females experience growth impairments and metabolic dysfunction arising from inhalant misuse, but data on sex-differences are inconclusive. Inhalant misuse in early adolescence may impact menarche and subsequent reproductive capacity, but studies have predominantly focused on the effects of inhalants on offspring rather than on the exposed female. There is limited evidence of sex-differences in relation to cognitive outcomes following exposure to inhalants in pre-clinical models. Females are at an increased risk of psychological harms associated with inhalant misuse, particularly depression and suicidal behaviour. CONCLUSIONS The type and magnitude of harms associated with inhalant misuse are sex-specific, but data are limited. We recommend that both pre-clinical and clinical studies of inhalant misuse include both males and females, and should specifically test for and report sex-differences. This can be used to build an evidence base for screening and interventions tailored to females.
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Affiliation(s)
- Rose Crossin
- Department of Population Health, University of Otago Christchurch campus, 34 Gloucester Street, Christchurch, 8140, New Zealand; Florey Institute of Neuroscience and Mental Health, 30 Royal Parade, Parkville, Melbourne, Victoria, 3052, Australia.
| | - Shalini Arunogiri
- Central Clinical School, Monash Alfred Psychiatry Research Centre, Level 4, 607 St Kilda Road, Melbourne, Victoria, 3004, Australia; Turning Point, Eastern Health, 110 Church Street, Richmond, Melbourne, Victoria, 3121, Australia
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Soares MV, Charão MF, Jacques MT, Dos Santos ALA, Luchese C, Pinton S, Ávila DS. Airborne toluene exposure causes germline apoptosis and neuronal damage that promotes neurobehavioural changes in Caenorhabditis elegans. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 256:113406. [PMID: 31662251 DOI: 10.1016/j.envpol.2019.113406] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/13/2019] [Accepted: 10/14/2019] [Indexed: 06/10/2023]
Abstract
Toluene is a highly volatile organic solvent present in gasoline. Exposure mainly occurs by absorption via the pulmonary tract and easily reaches the central nervous system, which causes toxic effects. Toluene toxicity has been described but not well established. The present work aimed to evaluate the effects of airborne exposure to toluene, the in vivo model Caenorhabditis elegans was assessed to determine whether nematode could be used to evaluate the effects of exposure to toluene and the possible mechanisms of toxicity of the solvent. Worms at the first or fourth larval stages were exposed to toluene for 48 or 24 h, respectively, in a laboratory-developed vapor chamber at concentrations of 450, 850, 1250 and 1800 ppm. We observed increases in worm mortality and significant developmental delays that occurred in a concentration-dependent manner. An increased incidence of apoptotic events in treated germline cells was shown, which was consistent with observed reductions in reproductive capacity. In addition, toluene promoted significant behavioural changes affecting swimming movements and radial locomotion, which were associated with changes in the fluorescence intensity and morphology of GABAergic and cholinergic neurons. We conclude that toluene exposure was toxic to C. elegans, with effects produced by the induction of apoptosis and neuronal damage.
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Affiliation(s)
- Marcell Valandro Soares
- Programa de Pós-Graduação em Bioquímica, Grupo de pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCe), Universidade Federal do Pampa, Uruguaiana, RS, 97500-970, Brazil
| | - Mariele Feiffer Charão
- Laboratório de Toxicologia Analítica, Universidade Feevale, Rua Rubem Berta, nº 200, Novo Hamburgo, CEP: 93525-090, RS, Brazil
| | - Mauricio Tavares Jacques
- Programa de Pós-Graduação em Bioquímica, Grupo de pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCe), Universidade Federal do Pampa, Uruguaiana, RS, 97500-970, Brazil; Laboratório de Experimentação em Neuropatologia - Departamento de Bioquímica, CCB, Universidade Federal de Santa Catarina, Bloco C, Trindade, Florianópolis, SC, CEP 88040-900, Brazil
| | - Ana Laura Anibaletto Dos Santos
- Laboratório de Toxicologia Analítica, Universidade Feevale, Rua Rubem Berta, nº 200, Novo Hamburgo, CEP: 93525-090, RS, Brazil
| | - Cristiane Luchese
- Programa de Pós-Graduação em Bioquímica e Bioprospecção, Laboratório de Pesquisa em Farmacologia Bioquímica (LaFarBio), Grupo de Pesquisa em Neurobiotecnologia (GPN), Universidade Federal de Pelotas, Pelotas, RS, 96010-900, Brazil
| | - Simone Pinton
- Programa de Pós-Graduação em Bioquímica, Grupo de pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCe), Universidade Federal do Pampa, Uruguaiana, RS, 97500-970, Brazil
| | - Daiana Silva Ávila
- Programa de Pós-Graduação em Bioquímica, Grupo de pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCe), Universidade Federal do Pampa, Uruguaiana, RS, 97500-970, Brazil.
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Ratner MH, Jabre JF, Ewing WM, Abou-Donia M, Oliver LC. Amyotrophic lateral sclerosis-A case report and mechanistic review of the association with toluene and other volatile organic compounds. Am J Ind Med 2018; 61:251-260. [PMID: 29125194 DOI: 10.1002/ajim.22791] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2017] [Indexed: 12/11/2022]
Abstract
Unmasking of latent neurodegenerative disease has been reported following exposure to chemicals that share one or more mechanisms of action in common with those implicated in the specific disease. For example, unmasking of latent Parkinson's disease (PD) has been associated with exposure to anti-dopaminergic agents, while the progression of pre-existing mild cognitive impairment and unmasking of latent Alzheimer's disease has been associated with exposure to general anesthetic agents which promote Aβ protein aggregation. This literature review and clinical case report about a 45-year-old man with no family history of motor neuron disease who developed overt symptoms of a neuromuscular disorder in close temporal association with his unwitting occupational exposure to volatile organic compounds (VOCs) puts forth the hypothesis that exposure to VOCs such as toluene, which disrupt motor function and increase oxidative stress, can unmask latent ALS type neuromuscular disorder in susceptible individuals.
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Affiliation(s)
- Marcia H Ratner
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts
| | - Joe F Jabre
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California
| | | | - Mohamed Abou-Donia
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
| | - L Christine Oliver
- Department of Medicine (Pulmonary and Critical Care Division), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
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Arabi M, Ghaedi M, Ostovan A. Water compatible molecularly imprinted nanoparticles as a restricted access material for extraction of hippuric acid, a biological indicator of toluene exposure, from human urine. Mikrochim Acta 2017. [DOI: 10.1007/s00604-016-2063-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Yoon JH, Seo HS, Lee J, Moon C, Lee K. Acute high-level toluene exposure decreases hippocampal neurogenesis in rats. Toxicol Ind Health 2016; 32:1910-1920. [DOI: 10.1177/0748233715599087] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Toluene is an organic solvent that is used in various industrial applications. Despite its usefulness, toluene has toxic effects on the brain and is a substance that is commonly abused. Toluene causes behavioral and functional abnormalities such as decreased memory capacity, cognitive impairment, and depression-like symptoms. However, the target sites and toxic mechanisms of inhaled toluene in the brain are poorly understood. In this study, we subjected Sprague-Dawley (SD) rats to acute high-level toluene exposure (7000 ppm) to investigate its neuronal toxicity, and in particular, its effect on neurogenesis in the hippocampus. In order to assay the effects of inhaled toluene on hippocampal neurogenesis, we measured the levels of neurogenesis markers Ki-67 and doublecortin (DCX) in the hippocampus 1, 2, 5, and 8 days after cessation of toluene exposure. In addition to assaying clinical signs, body weight, and bronchoalveolar lavage fluid, the liver, lungs, and kidneys were subjected to histopathological examination to investigate the toxic effects of high-level toluene exposure. Although abnormal neurological signs were observed after toluene exposure, these disappeared within 24 h and no toluene-related toxicological effects were observed in the liver, lungs, or kidneys. The animals exposed to toluene showed significantly decreased hippocampal neurogenesis, which persisted until the 8th and final day of measurement. Thus, acute high-level toluene exposure inhibited hippocampal neurogenesis and produced transient abnormal neurological signs, but did not produce toxicity in the other organs studied.
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Affiliation(s)
- Jin-ha Yoon
- The Institute for Occupational Health, Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Heung-Sik Seo
- Inhalation Toxicology Research Center, Korea Institute of Toxicology, Jeonbuk, Korea
- Toxicity Evaluation Team, Healthcare Research Institute, Korea Testing & Research Institute, Hwasun, Korea
| | - Jinsoo Lee
- Inhalation Toxicology Research Center, Korea Institute of Toxicology, Jeonbuk, Korea
| | - Changjong Moon
- Department of Veterinary Anatomy, Chonnam National University, Gwangju, Korea
| | - Kyuhong Lee
- Inhalation Toxicology Research Center, Korea Institute of Toxicology, Jeonbuk, Korea
- Human and Environment Toxicology, University of Science and Technology, Daejeon, Korea
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Kodavanti PRS, Royland JE, Moore-Smith DA, Besas J, Richards JE, Beasley TE, Evansky P, Bushnell PJ. Acute and subchronic toxicity of inhaled toluene in male Long-Evans rats: Oxidative stress markers in brain. Neurotoxicology 2015; 51:10-9. [PMID: 26343380 DOI: 10.1016/j.neuro.2015.09.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 10/23/2022]
Abstract
The effects of exposure to volatile organic compounds (VOCs), which are of concern to the EPA, are poorly understood, in part because of insufficient characterization of how human exposure duration impacts VOC effects. Two inhalation studies with multiple endpoints, one acute and one subchronic, were conducted to seek effects of the VOC, toluene, in rats and to compare the effects between acute and subchronic exposures. Adult male Long-Evans rats were exposed to toluene vapor (n=6 per group) at a concentration of 0 or 1019 ± 14 ppm for 6h in the acute study and at 0 ± 0, 10 ± 1.4, 97 ± 7, or 995 ± 43 ppm for 6h/d, 5d/week for 13 weeks in the subchronic study. For the acute study, brains were dissected on ice within 30 min of the end of exposure, while for the subchronic study, brains were dissected 18 h after the last exposure. Frontal cortex, hippocampus, cerebellum, and striatum were assayed for a variety of oxidative stress (OS) parameters including total aconitase (TA), protein carbonyls, glutathione peroxidase (GPX), glutathione reductase (GRD), glutathione transferase (GST), γ-glutamylcysteine synthetase (GCS), superoxide dismutase (SOD), total antioxidants (TAS), NADPH quinone oxidoreductase-1 (NQO1), and NADH ubiquinone reductase (UBIQ-RD) activities using commercially available kits. Following acute exposure, UBIQ-RD, GCS and GRD were increased significantly only in the cerebellum, while TAS was increased in frontal cortex. On the other hand, subchronic exposure affected several OS markers including increases in NQO1 and UBIQ-RD. The effect of subchronic toluene exposure on SOD and TAS was greater in the striatum than in the other brain regions. TA activity (involved in maintaining iron homeostasis and an indicator of DNA damage) was inhibited in striatum and cerebellum, increased in hippocampus, and unchanged in frontal cortex. Protein carbonyls increased significantly in both the frontal cortex and cerebellum. In general, the results showed that acute exposure to toluene affected OS parameters to a lesser extent than did subchronic exposure. These results suggest that toluene exposure induces OS in the brain and this may be a component of an adverse outcome pathway for some of the neurotoxic effects reported following toluene exposure.
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Affiliation(s)
- Prasada Rao S Kodavanti
- Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA.
| | - Joyce E Royland
- Genetic and Cellular Toxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Debra A Moore-Smith
- Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Jonathan Besas
- Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Judy E Richards
- Cardiopulmonary and Immunotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Tracey E Beasley
- Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Paul Evansky
- Inhalation Toxicology Facility, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Philip J Bushnell
- Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
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Yang M, Kim SH, Kim JC, Shin T, Moon C. Toluene induces depression-like behaviors in adult mice. Toxicol Res 2013; 26:315-20. [PMID: 24278539 PMCID: PMC3834495 DOI: 10.5487/tr.2010.26.4.315] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 10/29/2010] [Accepted: 11/06/2010] [Indexed: 11/20/2022] Open
Abstract
It has been clinically reported that toluene causes mental depression in humans. However, the detrimental effects of toluene exposure on brain function and the relation between features of mental depression and toluene exposure are poorly understood. This study evaluated depression-like behaviors in adult C57BL/6 mice after administration of toluene, and elucidated the effects of classical antidepressants on the depression-like behaviors. For the estimation of depression-like behaviors, tail suspension test (TST) and forcedswim test (FST) were performed 1, 4 and 16 days after toluene (0~1000 mg/kg bw) treatment. In addition, classical antidepressants such as fluoxetine (FLX, 20 mg/kg bw) and imipramine (IMI, 40 mg/kg bw) were administered 12 h and 1 h before the tests. In the TST and FST, toluene-treated mice exhibited a longer duration of immobility than vehicle-treated mice 1 and 4 days after toluene treatment. The depression-like behaviors were significantly reversed by FLX and IMI. The weight of the adrenal gland and the size of adrenocortical cells were significantly higher in toluene-treated mice compared to vehicle-treated controls. It is suggested that acute toluene exposure of adult mice is sufficiently detrimental to induce depression. In addition, this study has established a mouse model for a depressive state induced by toluene treatment.
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Affiliation(s)
- Miyoung Yang
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine,Chonnam National University, Gwangju 500-757
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Adolescent toluene inhalation in rats affects white matter maturation with the potential for recovery following abstinence. PLoS One 2012; 7:e44790. [PMID: 23028622 PMCID: PMC3445546 DOI: 10.1371/journal.pone.0044790] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 08/13/2012] [Indexed: 12/16/2022] Open
Abstract
Inhalant misuse is common during adolescence, with ongoing chronic misuse associated with neurobiological and cognitive abnormalities. While human imaging studies consistently report white matter abnormalities among long-term inhalant users, longitudinal studies have been lacking with limited data available regarding the progressive nature of such abnormalities, including the potential for recovery following periods of sustained abstinence. We exposed adolescent male Wistar rats (postnatal day 27) to chronic intermittent inhaled toluene (3,000 ppm) for 1 hour/day, 3 times/week for 8 weeks to model abuse patterns observed in adolescent and young adult human users. This dosing regimen resulted in a significant retardation in weight gain during the exposure period (p<0.05). In parallel, we performed longitudinal magnetic resonance imaging (T₂-weighted) and diffusion tensor imaging prior to exposure, and after 4 and 8 weeks, to examine the integrity of white matter tracts, including the anterior commissure and corpus callosum. We also conducted imaging after 8 weeks of abstinence to assess for potential recovery. Chronic intermittent toluene exposure during adolescence and early adulthood resulted in white matter abnormalities, including a decrease in axial (p<0.05) and radial (p<0.05) diffusivity. These abnormalities appeared region-specific, occurring in the anterior commissure but not the corpus callosum and were not present until after at least 4 weeks of exposure. Toluene-induced effects on both body weight and white matter parameters recovered following abstinence. Behaviourally, we observed a progressive decrease in rearing activity following toluene exposure but no difference in motor function, suggesting cognitive function may be more sensitive to the effects of toluene. Furthermore, deficits in rearing were present by 4 weeks suggesting that toluene may affect behaviour prior to detectable white matter abnormalities. Consequently, exposure to inhalants that contain toluene during adolescence and early adulthood appear to differentially affect white matter maturation and behavioural outcomes, although recovery can occur following abstinence.
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Kanter M. Protective effects of quercetine on the neuronal injury in frontal cortex after chronic toluene exposure. Toxicol Ind Health 2012; 29:643-51. [PMID: 22252859 DOI: 10.1177/0748233711430982] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of this study was designed to evaluate the possible protective effects of quercetine (QE) on the neuronal injury in the frontal cortex after chronic toluene exposure in rats. The rats were randomly allotted into one of the three experimental groups, namely, groups A (control), B (toluene treated) and C (toluene-treated with QE), where each group contains 10 animals. Control group received 1 ml of normal saline solution, and toluene treatment was performed by the inhalation of 3000 ppm toluene in an 8-h/day and 6-day/week order for 12 weeks. The rats in QE-treated group was given QE (15 mg/kg body weight) once a day intraperitoneally for 12 weeks, starting just after toluene exposure. Tissue samples were obtained for histopathological investigation. To date, no histopathological changes of neurodegeneration in the frontal cortex after chronic toluene exposure in rats by QE treatment have been reported. In this study, the morphology of neurons in the QE treatment group was well protected. Chronic toluene exposure caused severe degenerative changes, shrunken cytoplasm and extensively dark picnotic nuclei in neurons of the frontal cortex. We conclude that QE therapy causes morphologic improvement in neurodegeneration of frontal cortex after chronic toluene exposure in rats. We believe that further preclinical research into the utility of QE may indicate its usefulness as a potential treatment on neurodegeneration after chronic toluene exposure in rats.
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Affiliation(s)
- Mehmet Kanter
- Department of Histology and Embryology, Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Turkey.
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Beasley TE, Evansky PA, Bushnell PJ. Behavioral effects of sub-acute inhalation of toluene in adult rats. Neurotoxicol Teratol 2012; 34:83-9. [DOI: 10.1016/j.ntt.2011.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 11/10/2011] [Accepted: 11/11/2011] [Indexed: 10/15/2022]
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17
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Shih HT, Yu CL, Wu MT, Liu CS, Tsai CH, Hung DZ, Wu CS, Kuo HW. Subclinical abnormalities in workers with continuous low-level toluene exposure. Toxicol Ind Health 2011; 27:691-9. [PMID: 21543466 DOI: 10.1177/0748233710395348] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Short-term exposure to a high concentration (TWA > 100 ppm) of toluene can cause hepatotocixity and neurotoxicity in humans. Data on the effects of exposure to low levels of toluene, however, are controversial. In addition, few studies on the effects of toluene exposure on the autonomic nervous system have been conducted. Urine samples from 34 male factory workers in Taiwan who were exposed to low levels of toluene either intermittently (n = 13) or continuously (n = 21) were taken on a Monday morning after a 2-day hiatus and at the end of the workweek on Friday evening. Urinary hippuric acid levels were measured using high-performance liquid chromatography (HPLC). A complete blood work-up was also performed for each subject. The prevalence and severity of neurotoxic symptoms were investigated by a self-reported questionnaire, a neuropsychiatric battery, and sympathetic and peripheral nerve function tests. The mean value of urinary hippuric acid corrected for creatinine (Cr) was 0.34 ± 0.18 g/g Cr on Monday morning and 0.43 ± 0.26 g/g Cr on Friday evening. The difference in the mean value of urinary hippuric acid between the two periods (p < 0.01) and the odds ratio of impairment of sympathetic (OR = 4.13, p = 0.11) and peripheral nerves (OR = 6.94, p = 0.074) were higher in workers continuously exposed to toluene. In addition, workers who were continuously exposed to toluene had a lower mean platelet count (216 ± 41 × 10(6) /µL) than workers who were intermittently exposed (252 ± 40 × 10(6)/µL), (p = 0.018). Furthermore, there was a positive relationship between neurological abnormalities and a self-reported neuropsychiatric measurement (r = 0.35-0.66, p < 0.05) in all workers. These data suggest that continuous exposure to low levels of toluene may be associated with sympathetic and peripheral nerve dysfunction and sub-clinical hematological damage. Further research needs to be carried out regarding how chronic exposure to low-levels of toluene affects workers.
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Affiliation(s)
- Hsu-Tzu Shih
- Department of Occupational Medicine, Kuang Tien General Hospital, Taiwan, Institute of Environmental Health, China
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18
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Beasley TE, Evansky PA, Gilbert ME, Bushnell PJ. Behavioral effects of subchronic inhalation of toluene in adult rats. Neurotoxicol Teratol 2010; 32:611-9. [DOI: 10.1016/j.ntt.2010.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 05/07/2010] [Accepted: 05/17/2010] [Indexed: 10/19/2022]
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19
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Seo HS, Yang M, Song MS, Kim JS, Kim SH, Kim JC, Kim H, Shin T, Wang H, Moon C. Toluene inhibits hippocampal neurogenesis in adult mice. Pharmacol Biochem Behav 2009; 94:588-94. [PMID: 19969016 DOI: 10.1016/j.pbb.2009.11.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2009] [Revised: 11/02/2009] [Accepted: 11/30/2009] [Indexed: 10/20/2022]
Abstract
Toluene, a representative industrial solvent and abused inhalant, decreases neuronal activity in vitro and causes mental depression and cognitive impairment in humans. However, the effects of toluene on brain function and the sites of its action are poorly understood. This study investigated the temporal changes of neurogenesis in the hippocampus of adult C57BL/6 mice after acute administration of toluene using two immunohistochemical markers for neurogenesis, Ki-67 and doublecortin (DCX). In addition, after toluene treatment, depression-like behaviors and learning and memory tasks were examined to assess hippocampal neurogenesis-related behavioral dysfunction. The number of Ki-67- and DCX-positive cells in the dentate gyrus of adult hippocampi declined acutely between 0 h and 24 h after toluene treatment (500 mg/kg, i.p.) and increased gradually from 2 to 8 days post-administration. The level of Ki-67 and DCX immunoreactivity decreased in a dose-dependent manner within the range of toluene administered (0-1000 mg/kg). In tail suspension and forced-swim tests performed at 1 and 4 days after toluene treatment (500 mg/kg), mice showed significant depression-like behaviors compared to the vehicle-treated controls. In the contextual fear conditioning and object recognition memory test, the mice trained at 1 and 4 days after toluene treatment showed significant memory defects compared to the vehicle-treated controls. This study suggests that acute exposure to toluene reduces the rate of adult hippocampal neurogenesis and can cause hippocampal dysfunction such as depression and cognitive impairment.
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Affiliation(s)
- Heung-Sik Seo
- Department of Veterinary Anatomy, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
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20
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Zill P, Büttner A, Eisenmenger W, Müller J, Möller HJ, Bondy B. Predominant expression of tryptophan hydroxylase 1 mRNA in the pituitary: a postmortem study in human brain. Neuroscience 2009; 159:1274-82. [PMID: 19233335 DOI: 10.1016/j.neuroscience.2009.01.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 12/18/2008] [Accepted: 01/04/2009] [Indexed: 10/21/2022]
Abstract
Although the predominant role of tryptophan hydroxylase 2 (TPH2) in the CNS and its influence on the vulnerability to psychiatric disorders have clearly been demonstrated in several studies, the role of TPH1 on neuronal mechanisms, respectively on behavioral traits is still poorly understood. In a previous study of tryptophan hydroxylase 1 (TPH1) and TPH2 mRNA expression in different human brain regions we observed significantly higher TPH1 than TPH2 mRNA concentrations in the pituitary (unpublished observations). Considering the importance of the pituitary in the functional circuits between brain and body, we investigated the TPH1 and TPH2 mRNA expression in more detail, using human postmortem samples of the posterior and anterior pituitary compared to cortex, hippocampus and raphe nuclei. Specimens were available from different psychiatric patients (drug abusers, n=12; suicide victims, n=11; schizophrenics, n=9) and controls (n=15). Additionally we performed immunohistochemical analysis applying monospecific antibodies for both TPH isoforms to verify that the mRNA is of cellular and not just vascular or other origin. Highest TPH2 mRNA levels were observed in the raphe nuclei in patients and controls. By contrast, in the anterior and posterior pituitary TPH1 was found to be the predominantly expressed isoform in all subgroups. TPH1 and TPH2 mRNA expression in the further brain regions was only marginal and nearly identical except in the hypothalamus where higher TPH1 than TPH2 mRNA levels could be measured. Interindividual differences between the subgroups were not detectable. The results of the present study extended our previous findings by the additional immunohistochemical determination of the neuronal TPH1 and TPH2 protein expression in the anterior pituitary and provide evidence against a strictly separated duality of the serotonergic system. It seems that TPH1 might also have an impact on neuronal mechanisms via hypothalamic-pituitary-adrenal axis regulation by its predominant localization in the pituitary. These observations may open up new research strategies not only for several psychiatric disorders, but also for the relationship between psychiatric and somatic diseases.
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Affiliation(s)
- P Zill
- Department of Psychiatry, Ludwig-Maximilians-University Munich, Munich, Germany.
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21
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Henchcliffe C, Shungu DC, Mao X, Huang C, Nirenberg MJ, Jenkins BG, Beal MF. Multinuclear magnetic resonance spectroscopy for in vivo assessment of mitochondrial dysfunction in Parkinson's disease. Ann N Y Acad Sci 2009; 1147:206-20. [PMID: 19076443 DOI: 10.1196/annals.1427.037] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Parkinson's disease (PD) is a common and often devastating neurodegenerative disease affecting up to one million individuals in the United States alone. Multiple lines of evidence support mitochondrial dysfunction as a primary or secondary event in PD pathogenesis; a better understanding, therefore, of how mitochondrial function is altered in vivo in brain tissue in PD is a critical step toward developing potential PD biomarkers. In vivo study of mitochondrial metabolism in human subjects has previously been technically challenging. However, proton and phosphorus magnetic resonance spectroscopy ((1)H and (31)P MRS) are powerful noninvasive techniques that allow evaluation in vivo of lactate, a marker of anaerobic glycolysis, and high energy phosphates, such as adenosine triphosphate and phosphocreatine, directly reflecting mitochondrial function. This article reviews previous (1)H and (31)P MRS studies in PD, which demonstrate metabolic abnormalities consistent with mitochondrial dysfunction, and then presents recent (1)H MRS data revealing abnormally elevated lactate levels in PD subjects.
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Affiliation(s)
- Claire Henchcliffe
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY 10021, USA.
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22
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Kanter M. Nigella sativa and Derived Thymoquinone Prevents Hippocampal Neurodegeneration After Chronic Toluene Exposure in Rats. Neurochem Res 2007; 33:579-88. [DOI: 10.1007/s11064-007-9481-z] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Accepted: 08/16/2007] [Indexed: 11/30/2022]
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23
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Saunders CR, Das SK, Ramesh A, Shockley DC, Mukherjee S. Benzo(a)pyrene-induced acute neurotoxicity in the F-344 rat: role of oxidative stress. J Appl Toxicol 2007; 26:427-38. [PMID: 16858674 DOI: 10.1002/jat.1157] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Given the link between neurotoxicity and exposure to pollutants, the potential behavioral neurotoxicity of benzo(a)pyrene [B(a)P] was investigated. Studies have established that B(a)P requires metabolic activation to highly reactive species to elicit many of its adverse effects. This study investigated the perturbation of nervous system function by correlating behavioral changes with the metabolism of B(a)P, antioxidant enzyme levels and lipid peroxidation in selected brain regions. The neurobehavioral effects of single oral doses of B(a)P (25-200 mg kg(-1) body weight) on motor activity were examined in male F-344 rats at 2, 4, 6, 12, 24, 48, 72 and 96 h post treatment. Parent B(a)P and metabolites were measured at the above mentioned time points by reverse phase HPLC. The activity of several antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) and levels of malondialdehyde were determined at 6 and 96 h in both the striatum and hippocampus of B(a)P exposed rats. Suppression of motor activity (up to 70%) reached a maximum at 6 h, but was reversible at 96 h in all dose groups. The kinetics of disposition data show a strong link between B(a)P metabolism and the onset and duration of behavioral effects. Benzo(a)pyrene caused a 15-70% inhibition in the activity of superoxide dismutase and glutathione peroxidase and an enhancement in catalase and lipid peroxidation (up to 68%) in the striatum and hippocampus at 6 and 96 h post treatment, respectively. These findings suggest that B(a)P-induced acute neurobehavioral toxicity may occur through oxidative stress due to inhibition of the brain antioxidant scavenging system.
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Affiliation(s)
- Crystal R Saunders
- Department of Pharmacology, Meharry Medical College, Nashville, TN 37208, USA
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24
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Gordon CJ, Samsam TE, Oshiro WM, Bushnell PJ. Cardiovascular effects of oral toluene exposure in the rat monitored by radiotelemetry. Neurotoxicol Teratol 2006; 29:228-35. [PMID: 17140765 DOI: 10.1016/j.ntt.2006.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 09/12/2006] [Accepted: 10/16/2006] [Indexed: 11/16/2022]
Abstract
Toluene is a hazardous air pollutant that can be toxic to the nervous and cardiovascular systems. The cardiotoxicity data for toluene come from acute studies in anesthetized animals and from clinical observations made on toluene abusers and there is little known on the response of the cardiovascular and other autonomic processes to graded doses of toluene. This study assessed the effects of toluene (0.4, 0.8, and 1.2 g/kg; gavage) on heart rate (HR), blood pressure, core temperature (Tc), and motor activity (MA) in unrestrained, male Long-Evans rats monitored by telemetry. Toluene doses of 0.8 and 1.2 g/kg elicited significant elevations in HR, characterized by a transient 100 beats/min increase in HR lasting 1 h followed with a steady state tachycardia lasting >6 h. Overall, HR increased by 25 and 50 beats/min in the 0.8 and 1.2 g/kg groups, respectively. MA increased markedly in the 0.8 and 1.2 g/kg groups but the tachycardia persisted in spite of recovery of MA in the 0.8 g/kg group. There was a small (<0.5 degrees C) increase in Tc above controls in rats dosed with 0.8 g/kg toluene, whereas 1.2 g/kg toluene elicited a transient reduction in Tc followed by a small elevation lasting several hours. In a second study, rats were implanted with transmitters to monitor blood pressure (BP), and were administered with toluene as in the first study. HR, Tc, and MA were also monitored. The tachycardic effects of toluene at 0.8 and 1.2 g/kg were associated with a rise in blood pressure. Doses of 0.8 and 1.2 g/kg elicited a mean BP elevation of 6 and 16 mm Hg, respectively, for 7-hour post-dosing. The biphasic tachycardia to toluene suggests multiple sites for eliciting the cardiotoxic effects of this toxicant.
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Affiliation(s)
- Christopher J Gordon
- Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.
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25
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Gotoh N, Watanabe H, Osato R, Inagaki K, Iwasawa A, Wada S. Novel approach on the risk assessment of oxidized fats and oils for perspectives of food safety and quality. I. Oxidized fats and oils induces neurotoxicity relating pica behavior and hypoactivity. Food Chem Toxicol 2006; 44:493-8. [PMID: 16253412 DOI: 10.1016/j.fct.2005.08.023] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Revised: 07/21/2005] [Accepted: 08/29/2005] [Indexed: 11/27/2022]
Abstract
Food poisoning caused by deteriorated fat and oil in instant noodles was first reported in Japan approximately 40 years ago. In these cases, many people developed neurotoxic symptoms such as emesis and discomfort. The degree of oxidation of the fat and oil in the instant noodles that induced food poisoning was at least 100 meq/kg in peroxide value (PV). No general toxicity studies with animals, however, have examined the toxicity of fat and oil oxidized to that extent. In this study, pica behavior, a behavior characterized by eating a nonfood material such as kaolin and that relates to the degree of discomfort in animals, and alterations of locomotor activity of rats eating deteriorated fat and oil were measured. The groups fed fat and oil with at least 138.5 meq/kg PV consumed significantly more kaolin compared to the control group. Furthermore, rats that ate deteriorated fat and oil with at least 107.2 meq/kg PV had significantly decreased locomotor activity compared to control rats. These phenomena suggest that oxidized fat and oil with at least 100 meq/kg PV induce neurotoxicity. The toxicity of oxidized fat and oil has only been addressed using general toxicity tests, but the present results reveal the importance of evaluating toxicity by using other measures.
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Affiliation(s)
- N Gotoh
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
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Rango M, Bonifati C, Bresolin N. Parkinson's disease and brain mitochondrial dysfunction: a functional phosphorus magnetic resonance spectroscopy study. J Cereb Blood Flow Metab 2006; 26:283-90. [PMID: 16094320 DOI: 10.1038/sj.jcbfm.9600192] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In spite of several evidences for a mitochondrial impairment in Parkinson's disease (PD), so far it has not been possible to show in vivo mitochondrial dysfunction in the human brain of PD patients. The authors used the high temporal and spatial resolution 31 phosphorus magnetic resonance spectroscopy (31P MRS) technique, which they have previously developed in normal subjects and in patients with mitochondrial diseases to study mitochondrial function by observing high-energy phosphates (HEPs) and intracellular pH (pH) in the visual cortex of 20 patients with PD and 20 normal subjects at rest, during, and after visual activation. In normal subjects, HEPs remained unchanged during activation, but rose significantly (by 16%) during recovery, and pH increased during visual activation with a slow return to rest values. In PD patients, HEPs were within the normal range at rest and did not change during activation, but fell significantly (by 36%) in the recovery period; pH did not reveal a homogeneous pattern with a wide spread of values. Energy unbalance under increased oxidative metabolism requirements, that is, the postactivation phase, discloses a mitochondrial dysfunction that is present in the brain of patients with PD even in the absence of overt clinical manifestations, as in the visual cortex. This is in agreement with our previous findings in patients with mitochondrial disease without clinical central nervous system (CNS) involvement. The heterogeneity of the physicochemical environment (i.e., pH) suggests various degrees of subclinical brain involvement in PD. The combined use of MRS and brain activation is fundamental for the study of brain energetics in patients with PD and may prove an important tool for diagnostic purposes and, possibly, to monitor therapeutic interventions.
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Affiliation(s)
- Mario Rango
- Department of Neurological Sciences, Parkinson's Disease Center, Maggiore Policlinico Hospital, IRCCS, University of Milan, Milan, Italy.
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27
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Lo PS, Chen HH. Immunohistochemical localization of toluene-induced c-Fos protein expression in the rat brain. Toxicol Lett 2005; 157:151-60. [PMID: 15837002 DOI: 10.1016/j.toxlet.2005.01.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Revised: 01/25/2005] [Accepted: 01/25/2005] [Indexed: 11/15/2022]
Abstract
Although toluene is a widely abused substance, the neuronal populations and pathways mediating its effects are not well understood. Using c-Fos protein as a marker for neuronal activation, the present study investigated the pattern of c-Fos induction at 1h after various doses (0, 300, 750, and 1000 mg/kg, i.p.) of toluene injection in adult male rats. Quantitative analysis of Fos-immunoreactive neurons indicated toluene dose-related induced c-Fos immunoreactivity in the majority of structures examined. The structures included several cortex subareas (primary motor cortex, secondary motor cortex, somatosensory cortex, frontal association cortex, cigulate cortex area 1, cigulate cortex area 2, prelimbic cortex, infralimbic cortex, retrosplenial agranular cortex, ventral orbital cortex, lateral orbital cortex, and piriform cortex), ventral tegmental area, nucleus accumbens shell, thalamic nuclei (mediodorsal, lateral posterior, and laterodorsal ventrolateral) and pontine nuclei. However, the substantia nigra, caudate putamen, nucleus accumbens core, subthalamic nucleus, hippocampus and cerebellum were almost unaffected. The data demonstrate that toluene dose-related induced a unique pattern of c-Fos immunoreactivity. The widespread distribution of toluene-induced c-Fos expression seen in this study can be linked to the profound alterations in physiological function and behavior produced by this solvent.
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Affiliation(s)
- Pi-Shih Lo
- Department of Pharmacy, Buddhist Dalin Tzu Chi General Hospital, Chia Yi, Taiwan, ROC
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Kang SK, Rohlman DS, Lee MY, Lee HS, Chung SY, Anger WK. Neurobehavioral performance in workers exposed to toluene. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2005; 19:645-650. [PMID: 21783537 DOI: 10.1016/j.etap.2004.12.049] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Toluene is widely used in adhesive, printing, painting and petroleum industries in many countries. This study was conducted to examine the effect of chronic exposure to toluene below 100ppm on neurobehavioral performance using a computerized neurobehavioral test battery that emphasizes simple instructions and practice prior to testing. The Behavioral Assessment and Research System (BARS) with Korean language instructions was administered to 54 workers from three different industries: oil refinery, gravure printing, and rubber boat manufacturing. The battery consisted of the following tests: Digit Span (DS), Simple Reaction Time (SRT), Selective Attention (SAT), Finger Tapping (FT), and Symbol Digit (SD). Urine was collected at the end-of-shift to analyze urinary hippuric acid to assess exposure level to toluene. Based on the previous air toluene level, workers were divided into three groups: Low (21 workers, less than 10ppm), Moderate (13 workers, 20-30ppm) and High (20 workers, 70-80ppm) exposure status. Analysis of Covariance (ANCOVA) adjusting for age, education and work duration as covariates, was performed to examine the relationship between the neurobehavioral performance and the exposure groups. Poorer performance of the High exposure group was found on FT-preferred (F=7.034, p=0.002) and SAT latency (F=11.710, p=0.000). Age showed a significant correlation with SD (r=0.417, p=0.002) and SAT number correct (r=-0.460, p=0.000). Years of education and work duration were not significantly correlated with any items. This study supports that toluene exposure below 100ppm is associated with neurobehavioral changes and that high-level toluene exposure could cause not only attention and concentration, but also motor performance deficits.
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Affiliation(s)
- Seong-Kyu Kang
- Center for Occupational Diseases Research, Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency (KOSHA), 34-6 Gusan-dong Bupyong-gu, Incheon 403-711, Republic of Korea
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29
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Riegel AC, Ali SF, Torinese S, French ED. Repeated exposure to the abused inhalant toluene alters levels of neurotransmitters and generates peroxynitrite in nigrostriatal and mesolimbic nuclei in rat. Ann N Y Acad Sci 2005; 1025:543-51. [PMID: 15542760 DOI: 10.1196/annals.1316.079] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Toluene, a volatile hydrocarbon found in a variety of chemical compounds, is misused and abused by inhalation for its euphorigenic effects. Toluene's reinforcing properties may share a common characteristic with other drugs of abuse, namely, activation of the mesolimbic dopamine system. Prior studies in our laboratory found that acutely inhaled toluene activated midbrain dopamine neurons in the rat. Moreover, single systemic injections of toluene in rats produced a dose-dependent increase in locomotor activity which was blocked by depletion of nucleus accumbens dopamine or by pretreatment with a D2 dopamine receptor antagonist. Here we examined the effects of seven daily intraperitoneal injections of 600 mg/kg toluene on the content of serotonin and dopamine in the caudate nucleus (CN) and nucleus accumbens (NAC), substantia nigra, and ventral tegmental area at 2, 4, and 24 h after the last injection. Also, the roles of nitric oxide, peroxynitrite, and the production of 3-nitrosotyrosine (3-NT), in the CN and NAC were assessed at the same time points. Toluene treatments increased dopamine levels in the CN and NAC, and serotonin levels in CN, NAC, and ventral tegmental area. Measurements of the dopamine metabolite dihydroxyphenylacetic acid (DOPAC) further suggested a change in transmitter utilization in CN and NAC. Lastly, 3-NT levels also showed a differential change between CN and NAC, but at different time points post-toluene injection. These results point out the complexity of action of toluene on neurotransmitter function following a course of chronic exposure. Changes in the production of 3-NT also suggest that toluene-induced neurotoxicity may mediate via generation of peroxynitrite.
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Affiliation(s)
- A C Riegel
- Department of Pharmacology, University of Arizona College of Medicine, Tuscon, Arizona 85724-5050, USA
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Soulage C, Perrin D, Berenguer P, Pequignot JM. Sub-chronic exposure to toluene at 40ppm alters the monoamine biosynthesis rate in discrete brain areas. Toxicology 2004; 196:21-30. [PMID: 15036753 DOI: 10.1016/j.tox.2003.10.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2003] [Revised: 10/09/2003] [Accepted: 10/09/2003] [Indexed: 11/23/2022]
Abstract
Effects of long-term exposure to a sub-toxic concentration of toluene (40 ppm, 104 h per week, 16 weeks) have been studied on monoamine biosynthesis rate in rat. The activities of the rate limiting enzymes in catecholamine and 5-hydroxytryptamine biosynthesis tyrosine and tryptophan hydroxylase, respectively, were estimated in vivo by measuring the accumulation of l-dihydroxyphenylalanine and 5-hydroxytryptophan after pharmacological blockade of l-aromatic acid decarboxylases by NSD-1015 (100 mg kg(-1) ip). The sub-chronic exposure to toluene led to a significant and gender dependent alteration in both catecholamine and 5-hydroxytryptamine biosynthesis rate in brainstem catecholaminergic cell groups and hypothalamus. In females exposed to toluene, changes in tryptophan hydroxylation were found in rostral subset of A2C2 (+41%) and in A1C1 (+41%) while a decrease in A5 (-44%) and an increase in A2C2 (+28%) were found in tyrosine hydroxylation. In males, an increase in tryptophane hydroxylation was observed in rostral subset of A2C2 (+35%) while a decrease was observed in ventro-median hypothalamus (-17%). These results suggest that toluene exposure to a dose generally recognized as sub-toxic (40 ppm, no observed adverse effect level) leads to adverse effects on monoaminergic systems. Therefore, the neurotoxicity of toluene should be carefully re-evaluated taking into account not only the exposure level but also the duration.
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Affiliation(s)
- Christophe Soulage
- Laboratoire de Physiologie Intégrative Cellulaire et Moléculaire, UMR CNRS 5123, Université Claude Bernard Lyon I, bâtiment 404-Raphaël Dubois, Campus de la Doua, 69 622 Villeurbanne Cedex 08, France.
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Oshiro WM, Krantz QT, Bushnell PJ. A search for residual behavioral effects of trichloroethylene (TCE) in rats exposed as young adults. Neurotoxicol Teratol 2004; 26:239-51. [PMID: 15019957 DOI: 10.1016/j.ntt.2003.12.005] [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: 06/25/2003] [Revised: 12/16/2003] [Accepted: 12/16/2003] [Indexed: 10/26/2022]
Abstract
Trichloroethylene (TCE) is an organic solvent with robust acute effects on the nervous system, but poorly documented long-term effects. This study employed a signal detection task (SDT) to assess the persistence of effects of repeated daily inhalation of TCE on sustained attention in rats. Adult male Long-Evans rats inhaled TCE at 0, 1600, or 2400 ppm, 6 h/day for 20 days (n=8/group) and began learning the SDT 3 weeks later. Rats earned food by pressing one retractable response lever in a signal trial and a second lever in a blank (no signal) trial. TCE did not affect acquisition of the response rule or performance of the SDT after the intertrial interval (ITI) was changed from a constant value to a variable one. Increasing the trial presentation rate reduced accuracy equivalently in all groups. Injections of ethanol (0, 0.5, 1.0, 1.5 g/kg ip) and d-amphetamine (0, 0.1, 0.3, 1.0 mg/kg sc) systematically impaired performance as functions of drug dose. d-Amphetamine (1.0 mg/kg) reduced P(hit) more in the 2400-ppm TCE group than in the other groups. All rats required remedial training to learn a reversal of the response contingencies, which TCE did not interfere with. Thus, a history of exposure to TCE did not significantly alter learning or sustained attention in the absence of drugs. Although ethanol did not differentially affect the TCE groups, the effect of d-amphetamine is consistent with solvent-induced changes in dopaminergic functions in the CNS. Calculations indicated power values of 0.5 to 0.8 to detect main effects of TCE for the three primary endpoints.
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Affiliation(s)
- Wendy M Oshiro
- Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, B105-04, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
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