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Speen AM, Murray JR, Krantz QT, Davies D, Evansky P, Harrill JA, Everett LJ, Bundy JL, Dailey LA, Hill J, Zander W, Carlsten E, Monsees M, Zavala J, Higuchi MA. Benchmark Dose Modeling Approaches for Volatile Organic Chemicals using a Novel Air-Liquid Interface In Vitro Exposure System. Toxicol Sci 2022; 188:88-107. [PMID: 35426944 DOI: 10.1093/toxsci/kfac040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Inhalation is the most relevant route of volatile organic chemical (VOC) exposure; however, due to unique challenges posed by their chemical properties and poor solubility in aqueous solutions, in vitro chemical safety testing is predominantly performed using direct application dosing/submerged exposures. To address the difficulties in screening toxic effects of VOCs, our cell culture exposure system permits cells to be exposed to multiple concentrations at air-liquid interface (ALI) in a 24-well format. ALI exposure methods permit direct chemical-to-cell interaction with the test article at physiological conditions. In the present study, BEAS-2B and primary normal human bronchial epithelial cells (pHBEC) are used to assess gene expression, cytotoxicity, and cell viability responses to a variety of volatile chemicals including acrolein, formaldehyde, 1,3-butadiene, acetaldehyde, 1-bromopropane, carbon tetrachloride, dichloromethane, and trichloroethylene. BEAS-2B cells were exposed to all the test agents, while pHBECs were only exposed to the latter four listed above. The VOC concentrations tested elicited only slight cell viability changes in both cell types. Gene expression changes were analyzed using benchmark dose (BMD) modeling. The BMD for the most sensitive gene set was within one order of magnitude of the threshold-limit value reported by the American Conference of Governmental Industrial Hygienists, and the most sensitive gene sets impacted by exposure correlate to known adverse health effects recorded in epidemiologic and in vivo exposure studies. Overall, our study outlines a novel in vitro approach for evaluating molecular-based points-of-departure in human airway epithelial cell exposure to volatile chemicals.
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Affiliation(s)
- Adam M Speen
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, Tennessee 37830, USA
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Jessica R Murray
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Quentin Todd Krantz
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - David Davies
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Paul Evansky
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Joshua A Harrill
- CCTE, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Logan J Everett
- CCTE, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Joseph L Bundy
- CCTE, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Lisa A Dailey
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Jazzlyn Hill
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
- Oak Ridge Associated Universities (ORAU), Oak Ridge, Tennessee 37830, USA
| | - Wyatt Zander
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
- Oak Ridge Associated Universities (ORAU), Oak Ridge, Tennessee 37830, USA
| | - Elise Carlsten
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
- Oak Ridge Associated Universities (ORAU), Oak Ridge, Tennessee 37830, USA
| | - Michael Monsees
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
- Oak Ridge Associated Universities (ORAU), Oak Ridge, Tennessee 37830, USA
| | - Jose Zavala
- MedTec BioLab Inc., Hillsborough, North Carolina 27278, USA
| | - Mark A Higuchi
- CPHEA, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
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Trends of Studies on Controlled Halogenated Gases under International Conventions during 1999–2018 Using Bibliometric Analysis: A Global Perspective. SUSTAINABILITY 2022. [DOI: 10.3390/su14020806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
A lot of research on international convention-controlled halogenated gases (CHGs) has been carried out. However, few bibliometric analyses and literature reviews exist in this field. Based on 734 articles extracted from the Science Citation Index (SCI) Expanded database of the Web of Science, we provided the visualisation for the performance of contributors and trends in research content by using VOSviewer and Science of Science (Sci2). The results showed that the United States was the most productive country, followed by the United Kingdom and China. The National Oceanic and Atmospheric Administration had the largest number of publications, followed by the Massachusetts Institute of Technology (MIT) and the University of Bristol. In terms of disciplines, environmental science and meteorological and atmospheric science have contributed the most. By using cluster analysis of all keywords, four key research topics of CHGs were identified and reviewed: (1) emissions calculation, (2) physicochemical analysis of halocarbons, (3) evaluation of replacements, and (4) environmental impact. The change in research substances is closely related to the phase-out schedule of the Montreal Protocol. In terms of environmental impact, global warming has always been the most important research hotspot, whereas research on ozone-depleting substances and biological toxicity shows a gradually rising trend.
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Zhang X, Morikawa K, Mori Y, Zong C, Zhang L, Garner E, Huang C, Wu W, Chang J, Nagashima D, Sakurai T, Ichihara S, Oikawa S, Ichihara G. Proteomic analysis of liver proteins of mice exposed to 1,2-dichloropropane. Arch Toxicol 2020; 94:2691-2705. [PMID: 32435916 DOI: 10.1007/s00204-020-02785-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 05/07/2020] [Indexed: 11/29/2022]
Abstract
1,2-Dichloropropane (1,2-DCP) is recognized as the causative agent for cholangiocarcinoma among offset color proof-printing workers in Japan. The aim of the present study was to characterize the molecular mechanisms of 1,2-DCP-induced hepatotoxic effects by proteomic analysis. We analyzed quantitatively the differential expression of proteins in the mouse liver and investigated the role of P450 in mediating the effects of 1,2-DCP. Male C57BL/6JJcl mice were exposed to 0, 50, 250, or 1250 ppm 1,2-DCP and treated with either 1-aminobenzotriazole (1-ABT), a nonselective P450 inhibitor, or saline, for 8 h/day for 4 weeks. Two-dimensional difference in gel electrophoresis (2D-DIGE) combined with matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF/MS) was used to detect and identify proteins affected by the treatment. PANTHER overrepresentation test on the identified proteins was conducted. 2D-DIGE detected 61 spots with significantly different intensity between 0 and 250 ppm 1,2-DCP groups. Among them, 25 spots were identified by MALDI-TOF/TOF/MS. Linear regression analysis showed significant trend with 1,2-DCP level in 17 proteins in mice co-treated with 1-ABT. 1-ABT mitigated the differential expression of these proteins. The gene ontology enrichment analysis showed overrepresentation of proteins functionally related to nickel cation binding, carboxylic ester hydrolase activity, and catalytic activity. The results demonstrated that exposure to 1,2-DCP altered the expression of proteins related with catalytic and carboxylic ester hydrolase activities, and that such effect was mediated by P450 enzymatic activity.
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Affiliation(s)
- Xiao Zhang
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan.,Department of Toxicology, Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou, 510300, People's Republic of China
| | - Kota Morikawa
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Yurie Mori
- Mie University Graduate School of Medicine, Tsu, 514-8507, Japan
| | - Cai Zong
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Lingyi Zhang
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Edwin Garner
- Lovelace Respiratory Research Institute, Albuquerque, NM, 87108, USA
| | - Chinyen Huang
- Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Wenting Wu
- Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Jie Chang
- Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Daichi Nagashima
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Toshihiro Sakurai
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Sahoko Ichihara
- Jichi Medical University School of Medicine, Shimotsuke, 329-0498, Japan
| | - Shinji Oikawa
- Mie University Graduate School of Medicine, Tsu, 514-8507, Japan
| | - Gaku Ichihara
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan.
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Exposure to acrylamide decreases noradrenergic axons in rat brain. Neurotoxicology 2020; 78:127-133. [PMID: 32147327 DOI: 10.1016/j.neuro.2020.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 03/02/2020] [Accepted: 03/05/2020] [Indexed: 12/22/2022]
Abstract
PURPOSE Acrylamide is known to induce disorders in the central nervous system in humans and experimental animals. The present study investigated effects of exposure to acrylamide on adult neurogenesis, noradrenergic axons and the level of norepinephrine in the brain of male rats. METHOD Four groups of 12 male Wistar rats each were exposed to acrylamide at 0, 0.2, 2 and 20 mg/kg body weight by gavage for 5 weeks. Six rats of each groups were injected with 5-bromo-2'-deoxy-uridine (BrdU) after five-week exposure to acrylamide to examine proliferative cells in the dentate gyrus using immunostaining. Density of noradrenergic and serotonergic axons in the prefrontal cortex, hippocampus and cortex behind the bregma was quantified. Remaining 6 rats were decapitated after the last exposure and brains were dissected out to measure monoamine level in the hippocampus and prefrontal cortex using high performance liquid chromatography. RESULT Exposure to acrylamide dose-dependently decreased the density of noradrenergic axons in the prefrontal cortex with a significant change at 20 mg/kg. Norepinephrine level decreased in the hippocampus at 20 mg/kg. Exposure to acrylamide at 20 mg/kg or less did not change the number of BrdU positive cells, but the result should be considered preliminary. CONCLUSION The results show that oral exposure to acrylamide induces decrease in noradrenergic axons and norepinephrine level in the brain of rats. Given the similar effects are observed in 1-bromopropane-exposed rats, there may be the common mechanism in the toxicity of soft electrophiles to the central nervous system.
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Suo J, Zhang C, Wang P, Hou L, Wang Q, Zhao X. Allyl Sulfide Counteracts 1-Bromopropane-Induced Neurotoxicity by Inhibiting Neuroinflammation and Oxidative Stress. Toxicol Sci 2020; 167:397-407. [PMID: 30247689 DOI: 10.1093/toxsci/kfy240] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Chronic exposure to 1-bromopropane (1-BP), an alternative to ozone-depleting solvents, produces potential neurotoxicity in occupational populations. However, no therapeutic strategy is available currently. Accumulating evidence suggests that cytochrome P4502E1 (CYP2E1) is critical for the active metabolism of 1-BP. The purpose of this study is aimed to test whether inhibition of CYP2E1 by allyl sulfide, a specific inhibitor of CYP2E1, could be able to protect against 1-BP-induced neurotoxicity. Male Wistar rats were intoxicated with 1-BP for 9 continuous weeks with or without allyl sulfide pretreatment. Results clearly demonstrated that 1-BP exposure induced decrease in NeuN+ cells and increase in cleaved caspase-3 expression and TUNEL+ cells in motor cortex of rats, which was significantly ameliorated by allyl sulfide. Allyl sulfide treatment also recovered the motor performance of rats treated with 1-BP. Mechanistically, allyl sulfide-inhibited 1-BP-induced expression of CYP2E1 in microglia, which was associated with suppression of microglial activation and M1 polarization in motor cortex of rats. Reduced oxidative stress was also observed in rats treated with combined allyl sulfide and 1-BP compared with 1-BP alone group. Furthermore, we found that allyl sulfide abrogated 1-BP-induced activation of Nuclear factor(NF)-κB and GSH/Thioredoxin/ASK1 pathways, the key factor for the maintenance of M1 microglial inflammatory response and oxidative stress-related neuronal apoptosis, respectively. Thus, our results showed that allyl sulfide exerted neuroprotective effects in combating 1-BP-induced neurotoxicity through inhibition of neuroinflammation and oxidative stress. Blocking CYP2E1 activity by allyl sulfide might be a promising avenue for the treatment of neurotoxicity elicited by 1-BP and other related neurotoxicants.
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Affiliation(s)
- Jinning Suo
- Institute of Toxicology, School of Public Health, Shandong University, 250012 Jinan, Shandong Province, China
| | - Cuili Zhang
- Institute of Toxicology, School of Public Health, Shandong University, 250012 Jinan, Shandong Province, China
| | - Pin Wang
- Department of Neurology, the Second Hospital of Shandong University, Jinan 250012, China
| | - Liyan Hou
- Institute of Toxicology, School of Public Health, Dalian Medical University, Dalian 116044, China
| | - Qingshan Wang
- Institute of Toxicology, School of Public Health, Dalian Medical University, Dalian 116044, China
| | - Xiulan Zhao
- Institute of Toxicology, School of Public Health, Shandong University, 250012 Jinan, Shandong Province, China
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Abstract
Toxic peripheral neuropathies are an important form of acquired polyneuropathy produced by a variety of xenobiotics and different exposure scenarios. Delineating the mechanisms of neurotoxicants and determining the degenerative biological pathways triggered by peripheral neurotoxicants will facilitate the development of sensitive and specific biochemical-based methods for identifying neurotoxicants, designing therapeutic interventions, and developing structure-activity relationships for predicting potential neurotoxicants. This review presents an overview of the general concepts of toxic peripheral neuropathies with the goal of providing insight into why certain agents target the peripheral nervous system and produce their associated lesions. Experimental data and the main hypotheses for the mechanisms of selected agents that produce neuronopathies, axonopathies, or myelinopathies including covalent or noncovalent modifications, compromised energy or protein biosynthesis, and oxidative injury and disruption of ionic gradients across membranes are presented. The relevance of signaling between the main components of peripheral nerve, that is, glia, neuronal perikaryon, and axon, as a target for neurotoxicants and the contribution of active programmed degenerative pathways to the lesions observed in toxic peripheral neuropathies is also discussed.
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Nepal MR, Noh K, Shah S, Bist G, Lee ES, Jeong TC. Identification of DNA and glutathione adducts in male Sprague-Dawley rats exposed to 1-bromopropane. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2019; 82:502-513. [PMID: 31140386 DOI: 10.1080/15287394.2019.1622830] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Occupational exposure of workers to 1-bromopropane (1-BP) has raised concerns in industry for many years. Despite the known toxicity of this chemical, molecular events attributed to exposure to 1-BP have not been extensively studied. The aim of the present study was to examine the effects of 1-BP exposure on adduct formation with DNA and glutathione (GSH) in male Sprague-Dawley rats in an attempt to determine the early stages of toxicity. Following 6 h after either single or daily exposure to 1-BP for 3 days, N7-propyl guanine and S-propyl GSH were quantified in several organs by using liquid chromatography-mass spectrometry (LC-MS/MS). The results showed that N7-propyl guanine was maximally formed in liver followed by spleen, testes, and lung in both dose- and time-dependent manners. However, DNA adduct was not detected in cardiac tissue. In the case of S-propyl GSH, this compound was formed in the following order in various organs: liver > testes > spleen > kidney > lung > heart. In a subsequent in vitro study, formation of N7-propyl guanine initiated by 1-BP in calf thymus DNA was not markedly affected by addition of liver homogenates, which indicated that this chemical may be acting as a direct alkylating agent. In contrast, an in vitro study with free GSH demonstrated that 1-BP reduced GSH and elevated production of S-propyl GSH, and that the production of this adduct was significantly higher in the presence of active liver homogenates. Data indicated that formation of GSH adducts initiated by 1-BP might be associated with an enzyme-driven process. Although further characterization is necessary, it would appear that N7-propyl guanine and S-propyl GSH might serve as useful markers in cases of exposure assessment of 1-BP.
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Affiliation(s)
- Mahesh Raj Nepal
- a College of Pharmacy , Yeungnam University , Gyeongsan , South Korea
| | - Keumhan Noh
- a College of Pharmacy , Yeungnam University , Gyeongsan , South Korea
| | - Sajita Shah
- a College of Pharmacy , Yeungnam University , Gyeongsan , South Korea
| | - Ganesh Bist
- a College of Pharmacy , Yeungnam University , Gyeongsan , South Korea
| | - Eung Seok Lee
- a College of Pharmacy , Yeungnam University , Gyeongsan , South Korea
| | - Tae Cheon Jeong
- a College of Pharmacy , Yeungnam University , Gyeongsan , South Korea
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Nagashima D, Zhang L, Kitamura Y, Ichihara S, Watanabe E, Zong C, Yamano Y, Sakurai T, Oikawa S, Ichihara G. Proteomic analysis of hippocampal proteins in acrylamide-exposed Wistar rats. Arch Toxicol 2019; 93:1993-2006. [DOI: 10.1007/s00204-019-02484-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/15/2019] [Indexed: 01/08/2023]
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Stelljes M, Young R, Weinberg J. 28-Day somatic gene mutation study of 1-bromopropane in female Big Blue ® B6C3F1 mice via whole-body inhalation: Support for a carcinogenic threshold. Regul Toxicol Pharmacol 2019; 104:1-7. [PMID: 30779931 DOI: 10.1016/j.yrtph.2019.01.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 01/24/2019] [Accepted: 01/26/2019] [Indexed: 10/27/2022]
Abstract
A 2-year inhalation rat and mouse cancer study by the National Toxicology Program (NTP) on 1-bromopropane, a brominated solvent most commonly used as a vapor degreaser, showed significant increase in tumors in the lung of female mice and in the large intestine of male and female rats. The most sensitive endpoint was lung tumors in female mice. Mice of both sexes had hyperplasia and inflammation of the nose and showed regeneration of lung tissue. The NTP assumed that these tumors were due to genotoxic effects and that a linear dose-response relationship was appropriate. It is plausible that, similar to chloroform, hyperplasia and inflammation are required as initial events for tumor development. If true, then a threshold-based model may be more appropriate for 1-bromopropane. To test this hypothesis, a 28-day repeat dose inhalation Big Blue® Assay was conducted using female transgenic B6C3F1 mice. The target exposure concentrations and the exposure regimen were identical to those used by the NTP. Results demonstrated no elevation in mutant frequency of the cII transgene in lung, colon, or liver. Positive controls produced statistically significant increases in mutant frequencies across all tested tissues. These results demonstrate that 1-bromopropane does not induce cII mutants in lungs, colon, or liver under the testing conditions. These data have important ramifications in the quantitative evaluation of tumor results for this chemical and support a mechanism of action where a threshold for carcinogenicity is plausible.
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Affiliation(s)
| | - Robert Young
- MilliporeSigma, BioReliance(®) Testing Services, Rockville, MD, USA
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Xu L, Qiu X, Wang S, Wang Q, Zhao XL. NMDA Receptor Antagonist MK801 Protects Against 1-Bromopropane-Induced Cognitive Dysfunction. Neurosci Bull 2018; 35:347-361. [PMID: 30569431 DOI: 10.1007/s12264-018-0321-8] [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] [Received: 04/24/2018] [Accepted: 09/27/2018] [Indexed: 12/22/2022] Open
Abstract
Occupational exposure to 1-bromopropane (1-BP) induces learning and memory deficits. However, no therapeutic strategies are currently available. Accumulating evidence has suggested that N-methyl-D-aspartate receptors (NMDARs) and neuroinflammation are involved in the cognitive impairments in neurodegenerative diseases. In this study we aimed to investigate whether the noncompetitive NMDAR antagonist MK801 protects against 1-BP-induced cognitive dysfunction. Male Wistar rats were administered with MK801 (0.1 mg/kg) prior to 1-BP intoxication (800 mg/kg). Their cognitive performance was evaluated by the Morris water maze test. The brains of rats were dissected for biochemical, neuropathological, and immunological analyses. We found that the spatial learning and memory were significantly impaired in the 1-BP group, and this was associated with neurodegeneration in both the hippocampus (especially CA1 and CA3) and cortex. Besides, the protein levels of phosphorylated NMDARs were increased after 1-BP exposure. MK801 ameliorated the 1-BP-induced cognitive impairments and degeneration of neurons in the hippocampus and cortex. Mechanistically, MK801 abrogated the 1-BP-induced disruption of excitatory and inhibitory amino-acid balance and NMDAR abnormalities. Subsequently, MK801 inhibited the microglial activation and release of pro-inflammatory cytokines in 1-BP-treated rats. Our findings, for the first time, revealed that MK801 protected against 1-BP-induced cognitive dysfunction by ameliorating NMDAR function and blocking microglial activation, which might provide a potential target for the treatment of 1-BP poisoning.
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Affiliation(s)
- Lin Xu
- School of Public Health, Shandong University, Jinan, 250012, China
| | - Xiaofei Qiu
- School of Public Health, Shandong University, Jinan, 250012, China
| | - Shuo Wang
- School of Pharmacy, Liaocheng University, Liaocheng, 252000, China
| | - Qingshan Wang
- School of Public Health, Dalian Medical University, Dalian, 116044, China.
| | - Xiu-Lan Zhao
- School of Public Health, Shandong University, Jinan, 250012, China.
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Zhang X, Zong C, Zhang L, Garner E, Sugie S, Huang C, Wu W, Chang J, Sakurai T, Kato M, Ichihara S, Kumagai S, Ichihara G. Exposure of Mice to 1,2-Dichloropropane Induces CYP450-Dependent Proliferation and Apoptosis of Cholangiocytes. Toxicol Sci 2017; 162:559-569. [DOI: 10.1093/toxsci/kfx272] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Xiao Zhang
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Guangdong Provincial Key Laboratory of Occupational Disease Prevention and Treatment, Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou 510300, China
| | - Cai Zong
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Lingyi Zhang
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Edwin Garner
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
| | - Shigeyuki Sugie
- Department of Diagnostic Pathology, Asahi University Murakami Memorial Hospital, Gifu 500-8523, Japan
| | - Chinyen Huang
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Wenting Wu
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Jie Chang
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Toshihiro Sakurai
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
| | - Masashi Kato
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Sahoko Ichihara
- Department of Environmental and Preventive Medicine, Jichi Medical University School of Medicine, Shimotsuke 329-0498, Japan
| | - Shinji Kumagai
- Department of Occupational and Environmental Management, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Gaku Ichihara
- Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
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Miao R, Ding B, Zhang Y, Zhao R, Li Y, Zhu B. Large-scale label-free proteomics analysis of occupational poisoned patients of 1-bromopropane, workers exposed to 1-bromopropane and healthy individuals. Hum Exp Toxicol 2017; 37:3-12. [PMID: 28120620 DOI: 10.1177/0960327117689911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- R Miao
- The 8th People’s Hospital of Wuxi, Wuxi, China
| | - B Ding
- Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, China
| | - Y Zhang
- The 8th People’s Hospital of Wuxi, Wuxi, China
| | - R Zhao
- The 8th People’s Hospital of Wuxi, Wuxi, China
| | - Y Li
- The 8th People’s Hospital of Wuxi, Wuxi, China
| | - B Zhu
- Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, China
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13
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Zong C, Garner CE, Huang C, Zhang X, Zhang L, Chang J, Toyokuni S, Ito H, Kato M, Sakurai T, Ichihara S, Ichihara G. Preliminary characterization of a murine model for 1-bromopropane neurotoxicity: Role of cytochrome P450. Toxicol Lett 2016; 258:249-258. [DOI: 10.1016/j.toxlet.2016.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 06/13/2016] [Accepted: 07/10/2016] [Indexed: 11/27/2022]
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14
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Zong C, Zhang X, Huang C, Chang J, Garner CE, Sakurai T, Kato M, Ichihara S, Ichihara G. Role of cytochrome P450s in the male reproductive toxicity of 1-bromopropane. Toxicol Res (Camb) 2016; 5:1522-1529. [PMID: 30090453 DOI: 10.1039/c6tx00164e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/02/2016] [Indexed: 11/21/2022] Open
Abstract
1-Bromopropane (1BP) is widely used as an alternative to ozone-depleting solvents. The present study investigated the role of P450s in 1BP-induced male reproductive toxicity. Mice co-treated with 1-aminobenzotriazole (ABT), a non-selective P450 inhibitor, were exposed to 1BP at 0, 50, 250, or 1200 ppm, while saline-treated control mice were exposed to 1BP at 0, 50, or 250 ppm, for 4 weeks. In the saline-treated mice, exposure to 1BP at 250 ppm decreased the sperm count and sperm motility. Histopathological examination showed that exposure to 1BP at 50 and 250 ppm increased the number of elongated spermatids retained at the basal region of stage IX, X and XI seminiferous tubules, while exposure to 1BP at 250 ppm increased the number of periodic acid-Schiff (PAS)-positive round structures in stage IX, X, and XI seminiferous tubules. Co-treatment with ABT prevented the above changes induced by exposure to 1BP at 50 or 250 ppm. However, ABT-treated mice exposed to 1BP in the 1200 ppm group showed decreases in the weights of reproductive organs, epididymal sperm count and motility, increases in epididymal sperm with abnormal heads, retained spermatids and PAS-positive round structures in stages IX-XI, depletion of spermatogenic cells in part of the seminiferous tubules, and a small number of round spermatids in stage VII seminiferous tubules. The results at 50 and 250 ppm of 1-BP exposure indicate that P450s play important roles in 1BP-induced testicular toxicity. The control of P450 activity reduced 1BP-induced male reproductive toxicities including spermiation failure, reduction of epididymal sperm count and motility, and formation of PAS-positive round structures at postspermiation stages.
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Affiliation(s)
- Cai Zong
- Department of Occupational and Environmental Health , Faculty of Pharmaceutical Sciences , Tokyo University of Science , Noda 278-8510 , Japan . ; ; Tel: +81-4-7121-361.,Department of Occupational and Environmental Health , Nagoya University Graduate School of Medicine , Nagoya 466-8550 , Japan
| | - Xiao Zhang
- Department of Occupational and Environmental Health , Faculty of Pharmaceutical Sciences , Tokyo University of Science , Noda 278-8510 , Japan . ; ; Tel: +81-4-7121-361.,Department of Occupational and Environmental Health , Nagoya University Graduate School of Medicine , Nagoya 466-8550 , Japan
| | - Chinyen Huang
- Department of Occupational and Environmental Health , Nagoya University Graduate School of Medicine , Nagoya 466-8550 , Japan
| | - Jie Chang
- School of Public Health , Medical College of Soochow University , Suzhou 215123 , China.,Department of Occupational and Environmental Health , Nagoya University Graduate School of Medicine , Nagoya 466-8550 , Japan
| | - C Edwin Garner
- Lovelace Respiratory Research Institute , Albuquerque , New Mexico 87108 , USA
| | - Toshihiro Sakurai
- Department of Occupational and Environmental Health , Faculty of Pharmaceutical Sciences , Tokyo University of Science , Noda 278-8510 , Japan . ; ; Tel: +81-4-7121-361
| | - Masashi Kato
- Department of Occupational and Environmental Health , Nagoya University Graduate School of Medicine , Nagoya 466-8550 , Japan
| | - Sahoko Ichihara
- Graduate School of Regional Innovation Studies , Mie University , Tsu 514-8507 , Japan
| | - Gaku Ichihara
- Department of Occupational and Environmental Health , Faculty of Pharmaceutical Sciences , Tokyo University of Science , Noda 278-8510 , Japan . ; ; Tel: +81-4-7121-361
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15
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Huang F, Ichihara S, Yamada Y, Banu S, Ichihara G. Effect of 4-week inhalation exposure to 1-bromopropane on blood pressure in rats. J Appl Toxicol 2016; 37:331-338. [PMID: 27452781 DOI: 10.1002/jat.3364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 06/18/2016] [Accepted: 06/18/2016] [Indexed: 01/12/2023]
Abstract
The pathophysiology of hypertension is complex and multifactorial, and includes exposure to various chemical substances. Several recent studies have documented the reproductive and neurological toxicities of 1-bromopropane (1-BP). Given that 1-BP increased reactive oxygen species in the brain of rats, we hypothesized that 1-BP also has cardiovascular toxicity through increased oxidative stress. To test this hypothesis, male F344 and Wistar Nagoya rats (n = 7-8 per group per test) were exposed to 0 or 1000 ppm of 1-BP via inhalation for 4 weeks (8 h per day, 7 days per week). The exposure to 1-BP increased systolic blood pressure. This effect was associated with a significant decrease in the reduced/oxidized glutathione ratio. A significant increase in nitrotyrosine levels, activation of the NADPH oxidase pathway, which was evidenced by upregulation of gp91phox, a NADPH oxidase subunit, and significant decreases in the expressions of antioxidant molecules such as Cu/Zn- and Mn-superoxide dismutase catalase, and nuclear factor erythroid 2-related factor 2, were observed in the aortas of Wistar Nagoya rats exposed to 1-BP. Our results indicate that subacute (4-week) inhalation exposure to 1-BP increases blood pressure and suggest that this cardiovascular toxic effect is due, at least in part, to increased oxidative stress mediated through activation of the NADPH oxidase pathway. Further study is needed to assess whether NADPH oxidase activation causes the increase in blood pressure in the rats exposed to 1-BP. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Fen Huang
- Department of Environmental and Occupational Health, Nagoya University Graduate School of Medicine, Nagoya, Japan.,School of Public Health, Anhui Medical University, Anhui, China
| | - Sahoko Ichihara
- Department of Human Functional Genomics, Life Science Research Center, Mie University, Tsu, Japan
| | - Yuki Yamada
- Department of Human Functional Genomics, Life Science Research Center, Mie University, Tsu, Japan.,Japanese Red Cross Wakayama Medical Center, Wakayama, Japan
| | - Shameema Banu
- Department of Environmental and Occupational Health, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Obstetrics and Gynecology, Shri Sathya Sai Medical College Hospital and Research Center, Tamil Nadu, India
| | - Gaku Ichihara
- Department of Environmental and Occupational Health, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan
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16
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Wang TH, Wu ML, Wu YH, Tsai WJ, Lin KP, Wang CL, Yang CC, Deng JF. Neurotoxicity associated with exposure to 1-bromopropane in golf-club cleansing workers. Clin Toxicol (Phila) 2015; 53:823-6. [PMID: 26161839 DOI: 10.3109/15563650.2015.1064939] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND 1-Bromopropane (1-BP) is an alternative to ozone-depleting solvent that is used in degreasing, dry cleaning, spray adhesives, and aerosol solvents. Occupational exposure to 1-BP is associated with adverse peripheral sensory, motor, and central nervous system (CNS) effects. We report our Health Hazard and Medical Evaluation of 6 patients with neurotoxicity associated with occupational exposure to 1-BP. Case series and environmental evaluation. Six workers, 1 male and 5 female, were exposed to high ambient 1-BP concentrations while employed in a golf club cleaning factory. 1-BP was identified in the bulk solvent sample used by the workers and confirmed the workers' daily occupational exposure to 1-BP for 3-10 months. The major presenting symptoms were tingling pain, soreness in lower extremities, and paresthesia. N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys), a 1-BP metabolite, was identified by LC/MS/MS in the urine (0.171-1.74 mg/g-Cr) of these workers 5-26 days following 1-BP exposure. DISCUSSION AND CONCLUSION An occupational outbreak of 1-BP poisoning occurred as a result of recurrent power outages, condenser, and exhaust fans malfunction, and inadequate personal protection. Occupational exposure to 1-BP may result in peripheral neuropathy as well as adverse CNS effects. Urine AcPrCys may be a specific biomarker for 1-BP exposure.
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Affiliation(s)
- Te-Hao Wang
- Division of Clinical Toxicology and Occupational Medicine, Department of Medicine, Taipei Veterans General Hospital , Taipei , Taiwan
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17
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Garner CE, Liang S, Yin L, Yu X. Physiologically based pharmacokinetic modeling for 1-bromopropane in F344 rats using gas uptake inhalation experiments. Toxicol Sci 2015; 145:23-36. [PMID: 25634537 DOI: 10.1093/toxsci/kfv018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
1-Bromopropane (1-BP) was introduced into the workplace as an alternative to ozone-depleting solvents and increasingly used in manufacturing industry. The potential exposure to 1-BP and the current reports of adverse effects associated with occupational exposure to high levels of 1-BP have increased the need to understand the mechanism of 1-BP toxicity in animal models as a mean of understanding risk in workers. Physiologically based pharmacokinetic (PBPK) model for 1-BP has been developed to examine 2 metabolic pathway assumptions for gas-uptake inhalation study. Based on previous gas-uptake experiments in the Fischer 344 rat, the PBPK model was developed by simulating the 1-BP concentration in a closed chamber. In the model, we tested the hypothesis that metabolism responsibilities were shared by the p450 CYP2E1 and glutathione (GSH) conjugation. The results showed that 2 metabolic pathways adequately simulated 1-BP closed chamber concentration. Furthermore, the above model was tested by simulating the gas-uptake data of the female rats pretreated with 1-aminobenzotrizole, a general P450 suicide inhibitor, or d,l-buthionine (S,R)-sulfoximine, an inhibitor of GSH synthesis, prior to exposure to 800 ppm 1-BP. The comparative investigation on the metabolic pathway of 1-BP through the PBPK modeling in both sexes provides critical information for understanding the role of p450 and GSH in the metabolism of 1-BP and eventually helps to quantitatively extrapolate current animal studies to human.
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Affiliation(s)
- C Edwin Garner
- *Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108 and Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia 30602
| | - Shenxuan Liang
- *Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108 and Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia 30602
| | - Lei Yin
- *Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108 and Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia 30602
| | - Xiaozhong Yu
- *Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108 and Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia 30602
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Huang Z, Ichihara S, Oikawa S, Chang J, Zhang L, Hu S, Huang H, Ichihara G. Hippocampal phosphoproteomics of F344 rats exposed to 1-bromopropane. Toxicol Appl Pharmacol 2015; 282:151-60. [PMID: 25448045 DOI: 10.1016/j.taap.2014.10.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/16/2014] [Accepted: 10/21/2014] [Indexed: 11/18/2022]
Abstract
1-Bromopropane (1-BP) is neurotoxic in both experimental animals and human. To identify phosphorylated modification on the unrecognized post-translational modifications of proteins and investigate their role in 1-BP-induced neurotoxicity, changes in hippocampal phosphoprotein expression levels were analyzed quantitatively in male F344 rats exposed to 1-BP inhalation at 0, 400, or 1000 ppm for 8 h/day for 1 or 4 weeks. Hippocampal protein extracts were analyzed qualitatively and quantitatively by Pro-Q Diamond gel staining and SYPRO Ruby staining coupled with two-dimensional difference in gel electrophoresis (2D-DIGE), respectively, as well as by matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) to identify phosphoproteins. Changes in selected proteins were further confirmed by Manganese II (Mn(2+))-Phos-tag SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Bax and cytochrome c protein levels were determined by western blotting. Pro-Q Diamond gel staining combined with 2D-DIGE identified 26 phosphoprotein spots (p<0.05), and MALDI-TOF/MS identified 18 up-regulated proteins and 8 down-regulated proteins. These proteins are involved in the biological process of response to stimuli, metabolic processes, and apoptosis signaling. Changes in the expression of phosphorylated 14-3-3 θ were further confirmed by Mn(2+)-Phos-tag SDS-PAGE. Western blotting showed overexpression of Bax protein in the mitochondria with down-regulation in the cytoplasm, whereas cytochrome c expression was high in the cytoplasm but low in the mitochondria after 1-BP exposure. Our results suggest that the pathogenesis of 1-BP-induced hippocampal damage involves inhibition of antiapoptosis process. Phosphoproteins identified in this study can potentially serve as biomarkers for 1-BP-induced neurotoxicity.
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Affiliation(s)
- Zhenlie Huang
- Guangdong Provincial Key Laboratory of Occupational Disease Prevention and Treatment, Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou 510-300, PR China; Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Sahoko Ichihara
- Graduate School of Regional Innovation Studies, Mie University, Tsu 514-8507, Japan
| | - Shinji Oikawa
- Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Mie 514-8507, Japan
| | - Jie Chang
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Graduate School of Regional Innovation Studies, Mie University, Tsu 514-8507, Japan
| | - Lingyi Zhang
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan
| | - Shijie Hu
- Guangdong Provincial Key Laboratory of Occupational Disease Prevention and Treatment, Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou 510-300, PR China
| | - Hanlin Huang
- Guangdong Provincial Key Laboratory of Occupational Disease Prevention and Treatment, Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou 510-300, PR China.
| | - Gaku Ichihara
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda 278-8510, Japan.
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19
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Guo Y, Yuan H, Jiang L, Yang J, Zeng T, Xie K, Zhang C, Zhao X. Involvement of decreased neuroglobin protein level in cognitive dysfunction induced by 1-bromopropane in rats. Brain Res 2014; 1600:1-16. [PMID: 25557405 DOI: 10.1016/j.brainres.2014.12.046] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 11/27/2014] [Accepted: 12/10/2014] [Indexed: 12/30/2022]
Abstract
1-Bromopropane (1-BP) is used as a substitute for ozone-depleting solvents (ODS) in industrial applications. 1-BP could display central nervous system (CNS) neurotoxicity manifested by cognitive dysfunction. Neuroglobin (Ngb) is an endogenous neuroprotectant and is predominantly expressed in the nervous system. The present study aimed to investigate Ngb involvement in CNS neurotoxicity induced by 1-BP in rats. Male Wistar rats were randomly divided into 5 groups (n=14) and treated with 0, 100, 200, 400 and 800 mg/kg bw 1-BP, respectively, by gavage for consecutive 12 days. Rats displayed cognitive dysfunction dose-dependently through Morris water maze (MWM) test. Significant neuron loss in layer 5 of the prelimbic cortex (PL) was observed. Moreover, 1-BP decreased Ngb protein level in cerebral cortex and Ngb decrease was significantly positively correlated with cognitive dysfunction. Glutathione (GSH) content, GSH/oxidized glutathione (GSSG) ratio and glutamate cysteine ligase (GCL) activity decreased in cerebral cortex, coupled with the increase in GSSG content. GSH and GSH/GSSG ratio decrease were significantly positively correlated with cortical Ngb decrease. Additionally, levels of N-epsilon-hexanoyl-lysine (HEL) and 4-hydroxy-2-nonenal (4-HNE) modified proteins in cerebral cortex of 1-BP-treated rats increased significantly. In conclusion, it was suggested that 1-BP resulted in decreased endogenous neuroprotectant Ngb in cerebral cortex, which might play an important role in CNS neurotoxicity induced by 1-BP and that 1-BP-induced oxidative stress in cerebral cortex might partly be responsible for Ngb decrease.
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Affiliation(s)
- Ying Guo
- Institute of Toxicology, School of Public Health, Shandong University, 44 West Wenhua Road, Jinan, Shandong, PR China
| | - Hua Yuan
- Institute of Toxicology, School of Public Health, Shandong University, 44 West Wenhua Road, Jinan, Shandong, PR China
| | - Lulu Jiang
- Institute of Toxicology, School of Public Health, Shandong University, 44 West Wenhua Road, Jinan, Shandong, PR China
| | - Junlin Yang
- Institute of Toxicology, School of Public Health, Shandong University, 44 West Wenhua Road, Jinan, Shandong, PR China
| | - Tao Zeng
- Institute of Toxicology, School of Public Health, Shandong University, 44 West Wenhua Road, Jinan, Shandong, PR China
| | - Keqin Xie
- Institute of Toxicology, School of Public Health, Shandong University, 44 West Wenhua Road, Jinan, Shandong, PR China
| | - Cuili Zhang
- Institute of Toxicology, School of Public Health, Shandong University, 44 West Wenhua Road, Jinan, Shandong, PR China
| | - Xiulan Zhao
- Institute of Toxicology, School of Public Health, Shandong University, 44 West Wenhua Road, Jinan, Shandong, PR China.
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20
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Garner CE, Yu X. Species and sex-dependent toxicokinetics of 1-bromopropane: the role of hepatic cytochrome P450 oxidation and glutathione (GSH). Xenobiotica 2014; 44:644-56. [PMID: 24438363 DOI: 10.3109/00498254.2013.879624] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
1. The objectives of the current studies were to evaluate the factors influencing the toxicokinetics of 1-bromopropane (1-BP) in rodents after intravenous (IV) and inhalation exposure. 2. F-344 rats were administered 1-BP via IV bolus injection at 5 and 20 mg/kg and blood concentration determined versus time. F-344 rats and B6C3F1 mice were also exposed to starting inhalation concentrations 70, 240, 800 and 2700 ppm 1-BP in a closed gas uptake system and chamber 1-BP levels were monitored for 6 h. Plasma bromide concentrations were determined to estimate total metabolized dose. Rats were pretreated with chemical inhibitors of cytochrome P450 and glutathione (GSH) synthesis, prior to exposure to 1-BP at 800 ppm within inhalation chambers. 3. Systemic clearance of 1-BP in rat was rapid and decreased with increasing dose. As inhalation chamber concentration of 1-BP increased, the terminal elimination rates decreased. Half-life of 1-BP in rats following inhibition of P450 (9.6 h) or depletion of GSH (4.1 h) increased relative to controls (2.0 h) at 800 ppm. The percentage of 1-BP metabolized decreased with increasing inhalation exposure. Hepatic levels of GSH were significantly lowered regardless of the exposure level in both rats and mice. Chamber concentration-time curves were fit to a two compartment model which was used to estimate metabolic rate constants. 4. These data suggest that in rat, 1-BP clearance is saturable and that elimination is highly dependent on both P450 and GSH-dependent metabolism. This investigation in rodents may provide an understanding of interspecies differences in toxicokinetics and eventually aid translation of animal studies to human risk assessment.
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Affiliation(s)
- C Edwin Garner
- RTI International, Research Triangle Park , NC , USA and
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21
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Zhong Z, Zeng T, Xie K, Zhang C, Chen J, Bi Y, Zhao X. Elevation of 4-hydroxynonenal and malondialdehyde modified protein levels in cerebral cortex with cognitive dysfunction in rats exposed to 1-bromopropane. Toxicology 2013; 306:16-23. [PMID: 23395825 DOI: 10.1016/j.tox.2013.01.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 01/26/2013] [Accepted: 01/29/2013] [Indexed: 11/16/2022]
Abstract
1-Bromopropane (1-BP), an alternative to ozone-depleting solvents (ODS), exhibits central nervous system (CNS) toxicity in animals and humans. This study was designed to relate CNS damage by Morris water maze (MWM) test and oxidative stress to 1-BP exposure in the rat. Male Wistar rats were randomly divided into 4 groups (n=10), and treated with 0, 200, 400 and 800 mg/kgbw 1-BP for consecutive 12 days, respectively. From day 8 to day 12 of the experiment, MWM test was employed to assess the cognitive function of rats. The cerebral cortex of rats was obtained immediately following the 24h after MWM test conclusion. Glutathione (GSH), oxidized glutathione (GSSG) and total thiol (total-SH) content, GSH reductase (GR) and GSH peroxidase (GSH-Px) activities, malondialdehyde (MDA) level, as well as 4-hydroxynonenal (4-HNE) and MDA modified proteins in homogenates of cerebral cortex were measured. The obtained results showed that 1-BP led to cognitive dysfunction of rats, which was evidenced by delayed escape latency time and swimming distances in MWM performance. GSH and total-SH content, GSH/GSSG ratio, GR activity significantly decreased in cerebral cortex of rats, coupling with the increase of MDA level. 4-HNE and MDA modified protein levels obviously elevated after 1-BP exposure. GSH-Px activities in cerebral cortex of rats also increased. These data suggested that 1-BP resulted in enhanced lipid peroxidation of brain, which might play an important role in CNS damage induced by 1-BP.
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Affiliation(s)
- Zhixia Zhong
- Institute of Toxicology, School of Public Health, Shandong University, Jinan, Shandong Province 250012, China
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Zhang L, Nagai T, Yamada K, Ibi D, Ichihara S, Subramanian K, Huang Z, Mohideen SS, Naito H, Ichihara G. Effects of sub-acute and sub-chronic inhalation of 1-bromopropane on neurogenesis in adult rats. Toxicology 2012; 304:76-82. [PMID: 23266320 DOI: 10.1016/j.tox.2012.12.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 12/11/2012] [Accepted: 12/14/2012] [Indexed: 01/14/2023]
Abstract
PURPOSE 1-Bromopropane (1-BP) intoxication is associated with depression and cognitive and memory deficits. The present study tested the hypothesis that 1-BP suppresses neurogenesis in the dentate gyrus, which is involved in higher cerebral function, in adult rats. METHODS Four groups of 12 male Wistar rats were exposed to 0, 400, 800, 1000 ppm 1-BP, 8 h/day for 7 days. Another four groups of six rats each were exposed to 0, 400, 800 and 1000 ppm 1-BP for 2 weeks followed by 0, 200, 400 and 800 ppm for another 2 weeks, respectively. Another four groups of six rats each were exposed to 0, 200, 400 and 800 ppm 1-BP for 4 weeks. Rats were injected with 5-bromo-2'-deoxy-uridine (BrdU) after 4-week exposure at 1000/800 ppm to examine neurogenesis in the dentate gyrus by immunostaining. We measured factors known to affect neurogenesis, including monoamine levels, and mRNA expression levels of brain-derived neurotrophic factor (BDNF) and glucocorticoid receptor (GR), in different brain regions. RESULTS BrdU-positive cells were significantly lower in the 800/1000 ppm-4-week group than the control. 1-Week exposure to 1-BP at 800 and 1000 ppm significantly reduced noradrenalin level in the striatum. Four-week exposure at 800 ppm significantly decreased noradrenalin levels in the hippocampus, prefrontal cortex and striatum. 1-BP also reduced hippocampal BDNF and GR mRNA levels. CONCLUSION Long-term exposure to 1-BP decreased neurogenesis in the dentate gyrus. Downregulation of BDNF and GR mRNA expression and low hippocampal norepinephrine levels might contribute, at least in part, to the reduced neurogenesis.
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Affiliation(s)
- Lingyi Zhang
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Japan
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23
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Exposure to 1-bromopropane induces microglial changes and oxidative stress in the rat cerebellum. Toxicology 2012; 302:18-24. [DOI: 10.1016/j.tox.2012.07.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 07/12/2012] [Accepted: 07/13/2012] [Indexed: 11/22/2022]
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Mohideen SS, Ichihara S, Subramanian K, Huang Z, Naito H, Kitoh J, Ichihara G. Effects of exposure to 1-bromopropane on astrocytes and oligodendrocytes in rat brain. J Occup Health 2012. [PMID: 23183024 DOI: 10.1539/joh.12-0118-oa] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES Human cases of 1-bromopropane (1-BP) toxicity showed ataxic gait and cognitive dysfunction, whereas rat studies showed pyknotic shrinkage in cerebellar Purkinje cells and electrophysiological changes in the hippocampus. The present study investigated the effects of 1-BP on astrocytes and oligodendrocytes in the rat cerebellum and hippocampus to find sensitive markers of central nervous system toxicity. METHODS Forty-eight F344 rats were divided into four equal groups and exposed to 1-BP at 0, 400, 800 and 1,000 ppm for 8 h/day; 7 days/week, for 4 weeks. Nine and three rats per group were used for biochemical and histopathological studies, respectively. RESULTS Kluver-Barrera staining showed pyknotic shrinkage in the cytoplasm of Purkinje cells and nuclei of granular cells in the cerebellum at 1,000 ppm. Immunohistochemical analysis showed increased length of glial fibrillary acidic protein (GFAP)-positive processes of astrocytes in the cerebellum, hippocampus and dentate gyrus at 800 and 1,000 ppm. The myelin basic protein (MBP) level was lower at 1,000 ppm. The numbers of astrocytes and granular cells per tissue volume increased at 400 ppm or higher. CONCLUSION The present study showed that elongation of processes of astrocytes accompanies degeneration of granular cells and Purkinje cells in the cerebellum of the rats exposed to 1-BP. The decrease in MBP and number of oligodendrocytes suggest adverse effects on myelination. The increase in astrocyte population per tissue volume in the cerebellum might be a sensitive marker of 1-BP neurotoxicity, but the underlying mechanism for this change remains elusive.
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Affiliation(s)
- Sahabudeen Sheik Mohideen
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya University, Japan
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Huang Z, Ichihara S, Oikawa S, Chang J, Zhang L, Subramanian K, Mohideen SS, Ichihara G. Proteomic identification of carbonylated proteins in F344 rat hippocampus after 1-bromopropane exposure. Toxicol Appl Pharmacol 2012; 263:44-52. [DOI: 10.1016/j.taap.2012.05.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Revised: 04/18/2012] [Accepted: 05/26/2012] [Indexed: 01/05/2023]
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Ichihara G, Kitoh J, Li W, Ding X, Ichihara S, Takeuchi Y. Neurotoxicity of 1-bromopropane: Evidence from animal experiments and human studies. J Adv Res 2012. [DOI: 10.1016/j.jare.2011.04.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Meyer-Baron M, Kim EA, Nuwayhid I, Ichihara G, Kang SK. Occupational exposure to neurotoxic substances in Asian countries - challenges and approaches. Neurotoxicology 2011; 33:853-61. [PMID: 22202747 DOI: 10.1016/j.neuro.2011.12.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 12/07/2011] [Accepted: 12/12/2011] [Indexed: 10/14/2022]
Abstract
The fact that a conference on neurotoxicity was held in China triggered the idea to provide an insight into occupational diseases, their development and the approaches to investigate them in Asian countries. A historical review, a meta-analysis, and studies on humans and animals provide impressions on past and current problems. The Korean example showed that each newly introduced industry is accompanied by its own problems as regards occupational diseases. Mercury and carbon disulfide were of importance in the beginning, whereas solvents and manganese became important later. Outbreaks of diseases were important reasons to guide both the public and the governmental attention to prevention and allowed within a relatively short time considerable progress. As the example on the replacement of 2-bromopropane by 1-bromopropane showed, also the introduction of chemicals that are more beneficial for the environment may result in additional occupational risks. A lower mutagenicity of 1-bromopopane was shown to be associated with a greater neurotoxicity in Japanese studies. Although occupational health and diseases are commonly related to adults, child workers exposed to solvents were examined in a Lebanese study. The study started outlining the health hazards in young workers because they might be at a much greater risk due to the not yet completed maturation of their nervous system. That some occupational diseases are not yet a focus of prevention was shown by the study on pesticides. If at all, the serious health consequences resulting from excessive exposure were investigated. Research enabling precautionary actions was not available from the international literature. Despite globalization the knowledge on occupational diseases is not yet "globalized" and each country obviously undergoes its own development triggered by local experiences. Economic development that requires a healthy workforce, but also public interest that challenges governmental regulations further efforts on the prevention of occupational diseases. The paper reflects a summary of the talks presented at the symposium "Occupational Neurotoxicities in Asian Countries" as part of the 11th International Symposium on Neurobehavioral Methods and Effects in Occupational and Environmental Health.
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Affiliation(s)
- Monika Meyer-Baron
- Leibniz Research Centre for Working Environment and Human Factors, Germany.
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Huang Z, Ichihara S, Oikawa S, Chang J, Zhang L, Takahashi M, Subramanian K, Mohideen SS, Wang Y, Ichihara G. Proteomic analysis of hippocampal proteins of F344 rats exposed to 1-bromopropane. Toxicol Appl Pharmacol 2011; 257:93-101. [PMID: 21925529 DOI: 10.1016/j.taap.2011.08.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 08/23/2011] [Accepted: 08/26/2011] [Indexed: 12/28/2022]
Abstract
1-Bromopropane (1-BP) is a compound used as an alternative to ozone-depleting solvents and is neurotoxic both in experimental animals and human. However, the molecular mechanisms of the neurotoxic effects of 1-BP are not well known. To identify the molecular mechanisms of 1-BP-induced neurotoxicity, we analyzed quantitatively changes in protein expression in the hippocampus of rats exposed to 1-BP. Male F344 rats were exposed to 1-BP at 0, 400, or 1000 ppm for 8h/day for 1 or 4 weeks by inhalation. Two-dimensional difference in gel electrophoresis (2D-DIGE) combined with matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) were conducted to detect and identify protein modification. Changes in selected proteins were further confirmed by western blot. 2D-DIGE identified 26 proteins with consistently altered model (increase or decrease after both 1- and 4-week 1-BP exposures) and significant changes in their levels (p<0.05; fold change ≥ ± 1.2) at least at one exposure level or more compared with the corresponding controls. Of these proteins, 19 were identified by MALDI-TOF-TOF/MS. Linear regression analysis of 1-BP exposure level identified 8 differentially expressed proteins altered in a dose-dependent manner both in 1- and 4-week exposure experiments. The identified proteins could be categorized into diverse functional classes such as nucleocytoplasmic transport, immunity and defense, energy metabolism, ubiquitination-proteasome pathway, neurotransmitter and purine metabolism. Overall, the results suggest that 1-BP-induced hippocampal damage involves oxidative stress, loss of ATP production, neurotransmitter dysfunction and inhibition of ubiquitination-proteasome system.
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Affiliation(s)
- Zhenlie Huang
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
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Morgan DL, Nyska A, Harbo SJ, Grumbein SL, Dill JA, Roycroft JH, Kissling GE, Cesta MF. Multisite carcinogenicity and respiratory toxicity of inhaled 1-bromopropane in rats and mice. Toxicol Pathol 2011; 39:938-48. [PMID: 21859883 DOI: 10.1177/0192623311416374] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Two-year 1-bromopropane (1-BP) inhalation studies were conducted because of the potential for widespread exposure, the lack of chronic toxicity and carcinogenicity data, and the known carcinogenicity of structurally related compounds. Male and female F344/N rats and B6C3F1/N mice were exposed by inhalation to 0, 62.5 (mice only), 125, 250, or 500 (rats only) ppm 1-BP for 6 hr/day, 5 days/week for 105 weeks. Exposure of male and female rats to 1-BP resulted in significantly increased incidences of adenomas of the large intestine and skin neoplasms. In male rats, the incidence of malignant mesothelioma of the epididymis was statistically significantly increased at 500 ppm, but the biological significance of this common lesion is unclear. Incidences of pancreatic islet adenoma in male rats were significantly increased at all concentrations relative to concurrent controls but were within the historical control range for inhalation studies. There was no evidence of carcinogenic activity of 1-BP in male B6C3F1 mice; however, significantly increased incidences of alveolar/bronchiolar neoplasms of the lung were present in female mice. Exposure to 1-BP also resulted in increased incidences of nonneoplastic lesions in the nose of rats and mice, the larynx of rats and male mice, the trachea of female rats and male and female mice, and the lungs of mice. Inflammatory lesions with Splendore Hoeppli (S-H) material were present primarily in the nose and skin of exposed male and female rats, indicating that 1-BP caused immunosuppression.
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Affiliation(s)
- Daniel L Morgan
- National Institute of Environmental Health Sciences, National Toxicology Program, Research Triangle Park, North Carolina 27709, USA.
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Mohideen SS, Ichihara G, Ichihara S, Nakamura S. Exposure to 1-bromopropane causes degeneration of noradrenergic axons in the rat brain. Toxicology 2011; 285:67-71. [PMID: 21527306 DOI: 10.1016/j.tox.2011.04.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Revised: 04/07/2011] [Accepted: 04/08/2011] [Indexed: 11/18/2022]
Abstract
1-Bromopropane (1-BP) has been used as an alternative to ozone-depleting solvents. Previous studies showed that 1-BP is neurotoxic in animals and humans. In humans, exposure to 1-BP caused various neurological and neurobehavioral symptoms or signs including depressive or irritated mood. However, the neurobiological changes underlying the depressive symptoms induced by 1-BP remain to be determined. The depressive symptoms are thought to be associated with degeneration of axons containing noradrenaline and serotonin. Based on this hypothesis, the present study examined the effects of repeated exposure to 1-BP on serotonergic and noradrenergic axons. Exposure to 1-BP induced dose-dependent decreases in the density of noradrenergic axons in the rat prefrontal cortex, but no apparent change in the density of serotonergic axons. The results suggest that depressive symptoms in workers exposed to 1-BP are due, at least in part, to the degeneration of noradrenergic axons in the brain.
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Affiliation(s)
- Sahabudeen Sheik Mohideen
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
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Frasch HF, Dotson GS, Barbero AM. In vitro human epidermal penetration of 1-bromopropane. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2011; 74:1249-1260. [PMID: 21830855 DOI: 10.1080/15287394.2011.595666] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
1-Bromopropane (1-BP; CAS number 106-94-5), also known as n-propyl bromide, is a halogenated short-chain alkane used as an organic solvent with numerous commercial and industrial applications, including garment dry cleaning and vapor degreasing of metals. The purpose of this study was to determine the dermal absorption characteristics and corrosivity of 1-BP. Heat-separated human epidermal membranes were mounted on static diffusion cells. Different exposure scenarios were studied (infinite dose, finite dose, and transient exposure) using neat 1-BP and saturated aqueous solution as donor. Steady-state fluxes for infinite-dose neat 1-BP exposure averaged 625 to 960 μg cm(-2) h(-1). The finite-dose (10 μl/cm(2) = 13.5 mg/cm(2)) unoccluded donor resulted in penetration of <0.2% of the applied dose (22 μg/cm(2)). A 10-min transient exposure to infinite dose resulted in total penetration of 179 μg/cm(2). Steady-state 1-BP fluxes from neat application of a commercial dry cleaning solvent were similar (441 to 722 μg cm(-2) h(-1)). The permeability coefficient of 1-BP in water vehicle was 0.257 ± 0.141 cm/h. The absorption potential of 1-BP following dermal exposure is dependent upon the type and duration of exposure. Donor losses due to evaporation were approximately 500-fold greater than dermal absorption flux; evaporation flux was 420 mg cm(-2) h(-1). 1-BP is cytotoxic but not corrosive, based on results from a cultured reconstructed human epidermal model (EpiDerm Skin Corrosivity Test).
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Affiliation(s)
- H Frederick Frasch
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA.
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33
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Xin QQ, Yong Huang, Jie Li, Zhang WJ, Tao Yu, Hua Wang, Cheng Zhang, Ye DQ, Fen Huang. Apoptosis contributes to testicular toxicity induced by two isomers of bromopropanes. Toxicol Ind Health 2010; 26:513-24. [DOI: 10.1177/0748233710373083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this study was to investigate the different testicular toxicity and the role of apoptosis in the possible mechanism induced by the two isomers of bromopropanes (BPs) in the same dosage. Following the 14-day treatment with a single dose of 1-BP and 2-BP (1 g/kg), male rats were killed and a series of experiments were performed. 1-BP and 2-BP both significantly decreased the epididymal sperm count, while only 2-BP induced an increase in sperms with abnormal heads. Morphological evaluation showed that 1-BP did not cause morphological changes in seminiferous epithelium, but 2-BP treatment resulted in the disappearance of spermatogonia, atrophy of the seminiferous tubules and degeneration of germ cells. 2-BP significantly increased the TUNEL-positive cells and the activation of caspase-3 and decreased the genes and proteins expression of Bax, Bcl-2 and p53. In contrast, there were no significant changes in the expression of apoptosis-related genes and proteins in 1-BP group, though the TUNEL-positive cells were significantly increased. Taken together, this study indicated that those two isomers both have toxicity in male rats, however, the testicular toxicity and the role of apoptosis in the toxic mechanism induced by 1-BP and 2-BP may be different.
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Affiliation(s)
- Qian-Qian Xin
- Department of Epidemiology and Biostatistics, Anhui Medical University, Meishan Road 81, Hefei, China
| | - Yong Huang
- Department of Epidemiology and Biostatistics, Anhui Medical University, Meishan Road 81, Hefei, China
| | - Jie Li
- Department of Epidemiology and Biostatistics, Anhui Medical University, Meishan Road 81, Hefei, China
| | - Wan-Jun Zhang
- Department of Epidemiology and Biostatistics, Anhui Medical University, Meishan Road 81, Hefei, China
| | - Tao Yu
- Department of Toxicology, Anhui Medical University, Hefei, China
| | - Hua Wang
- Department of Toxicology, Anhui Medical University, Hefei, China
| | - Cheng Zhang
- Department of Toxicology, Anhui Medical University, Hefei, China
| | - Dong-Qing Ye
- Department of Epidemiology and Biostatistics, Anhui Medical University, Meishan Road 81, Hefei, China
| | - Fen Huang
- Department of Epidemiology and Biostatistics, Anhui Medical University, Meishan Road 81, Hefei, China,
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Liu F, Ichihara S, Valentine WM, Itoh K, Yamamoto M, Sheik Mohideen S, Kitoh J, Ichihara G. Increased susceptibility of Nrf2-null mice to 1-bromopropane-induced hepatotoxicity. Toxicol Sci 2010; 115:596-606. [PMID: 20211940 DOI: 10.1093/toxsci/kfq075] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
1-Bromopropane (1-BP) was introduced as an alternative to ozone-depleting solvents. However, it was found to exhibit neurotoxicity, reproductive toxicity, and hepatotoxicity in rodents and neurotoxicity in human. However, the mechanisms underlying the toxicities of 1-BP remain elusive. The present study investigated the role of oxidative stress in 1-BP-induced hepatotoxicity using nuclear factor erythroid 2-related factor 2 (Nrf2)-null mice. Groups of 24 male Nrf2-null mice and 24 male wild-type (WT) C57BL/6J mice were each divided into three groups of eight and exposed to 1-BP at 0, 100, or 300 ppm for 8 h/day for 28 days by inhalation. Liver histopathology showed significantly larger area of necrosis in Nrf2-null mice relative to WT mice at the same exposure level. Nrf2-null mice also had greater malondialdehyde (MDA) levels, higher ratio of oxidized glutathione/reduced form of glutathione, and lower total glutathione content. The constitutive level and the increase in ratio per exposure level of glutathione S-transferase (GST) activity were lower in the liver of Nrf2-null mice than WT mice. Exposure to 1-BP at 300 ppm increased the messenger RNA levels of heme oxygenase-1 (HO-1), glutamate-cysteine ligase modifier subunit (GcLm), glutamate-cysteine synthetase (GcLc), glutathione reductase, and NAD(P)H: quinone oxidoreductase 1 (NQO1) in WT mice but not in Nrf2-null mice except for GST Yc2. Nrf2-null mice were more susceptible to 1-BP-induced hepatotoxicity. That oxidative stress plays a role in 1-BP hepatotoxicity is deduced from the low expression levels and activities of antioxidant enzymes and high MDA levels in Nrf2-null mice.
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Affiliation(s)
- Fang Liu
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
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Anderson SE, Munson AE, Butterworth LF, Germolec D, Morgan DL, Roycroft JA, Dill J, Meade BJ. Whole-body inhalation exposure to 1-bromopropane suppresses the IgM response to sheep red blood cells in female B6C3F1 mice and Fisher 344/N rats. Inhal Toxicol 2010; 22:125-32. [PMID: 20041805 PMCID: PMC2832118 DOI: 10.3109/08958370902953910] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
1-Bromopropane (1-BP) is categorized as a high-production-volume chemical and is currently used in the manufacture of pharmaceuticals, pesticides, and other chemicals. Its usage is estimated to be around 5 million pounds per year, resulting in the potential for widespread exposure in the workplace. Case reports and animal studies have suggested exposure to this compound may cause adverse reproductive and neurological effects. Using a battery of immunological assays, the immunotoxicity of 1-BP after whole body inhalation exposure in both mice and rats was evaluated. Significant decreases in the spleen immunoglobulin (Ig) M response to sheep red blood cells (SRBC) were observed in both mice (125-500 ppm) and rats (1000 ppm) after exposure to 1-BP for 10 wk. In addition, total spleen cells and T cells were significantly decreased after approximately 4 wk of 1-BP exposure in both mice (125-500 ppm) and rats (1000 ppm). No change in natural killer (NK) cell activity was observed. The observed alterations in spleen cellularity, phenotypic subsets, and impairment of humoral immune function across species raise further concern about human exposure to 1-BP and demonstrate the need for additional investigations into potential adverse health effects.
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Affiliation(s)
- Stacey E Anderson
- National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA.
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36
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Lee SK, Kang MJ, Jeon TW, Ha HW, Yoo JW, Ko GS, Kang W, Jeong HG, Lyoo WS, Jeong TC. Role of metabolism in 1-bromopropane-induced hepatotoxicity in mice. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2010; 73:1431-1440. [PMID: 20954070 DOI: 10.1080/15287394.2010.511546] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A possible role of metabolism in 1-bromopropane (1-BP)-induced hepatotoxicity was investigated in male ICR mice. The depletion of glutathione (GSH) by formation of GSH conjugates was associated with increased hepatotoxicity in 1-BP-treated mice. The formation of S-propyl and 2-hydroxypropyl GSH conjugates were identified in the liver following 1-BP treatment. In addition, the formation of reactive metabolites of 1-BP by certain cytochrome P-450 (CYP) may be involved in 1-BP-induced hepatotoxicity. The decreased content of hepatic GSH produced by 1-BP was associated not only with increased activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) but also with elevated levels of hepatic thiobarbituric acid-reactive substance (TBARS) in mice where metabolic enzymes were induced by pretreatment with phenobarbital. In addition, the hepatotoxicity induced by 1-BP was prevented by pretreatment with SKF-525A. Taken together, the formation of reactive metabolites by CYP and depletion of GSH may play important roles in hepatotoxicity induced by 1-BP.
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Affiliation(s)
- Sang Kyu Lee
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
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37
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Changes in neurotransmitter receptor expression levels in rat brain after 4-week exposure to 1-bromopropane. Neurotoxicology 2009; 30:1078-83. [DOI: 10.1016/j.neuro.2009.06.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 06/10/2009] [Accepted: 06/20/2009] [Indexed: 11/18/2022]
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Hanley KW, Petersen MR, Cheever KL, Luo L. N-acetyl-S-(n-propyl)-l-cysteine in urine from workers exposed to 1-bromopropane in foam cushion spray adhesives. ANNALS OF OCCUPATIONAL HYGIENE 2009; 53:759-69. [PMID: 19706636 DOI: 10.1093/annhyg/mep051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
1-Bromopropane (1-BP) has been marketed as an alternative for ozone depleting and other solvents; it is used in aerosol products, adhesives, metal, precision, and electronics cleaning solvents. Mechanisms of toxicity of 1-BP are not fully understood, but it may be a neurological and reproductive toxicant. Sparse exposure information prompted this study using 1-BP air sampling and urinary metabolites. Mercapturic acid conjugates are excreted in urine from 1-BP metabolism involving debromination. Research objectives were to evaluate the utility of urinary N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) for assessing exposure to 1-BP and compare it to urinary bromide [Br((-))] previously reported for these workers. Forty-eight-hour urine specimens were obtained from 30 workers at two factories where 1-BP spray adhesives were used to construct polyurethane foam seat cushions. Urine specimens were also obtained from 21 unexposed control subjects. All the workers' urine was collected into composite samples representing three time intervals: at work, after work but before bedtime, and upon awakening. Time-weighted average (TWA) geometric mean breathing zone concentrations were 92.4 and 10.5 p.p.m. for spraying and non-spraying jobs, respectively. Urinary AcPrCys showed the same trend as TWA exposures to 1-BP: higher levels were observed for sprayers. Associations of AcPrCys concentrations, adjusted for creatinine, with 1-BP TWA exposure were statistically significant for both sprayers (P < 0.05) and non-sprayers (P < 0.01). Spearman correlation coefficients for AcPrCys and Br((-)) analyses determined from the same urine specimens were highly correlated (P < 0.0001). This study confirms that urinary AcPrCys is an important 1-BP metabolite and an effective biomarker for highly exposed foam cushion workers.
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Affiliation(s)
- Kevin W Hanley
- Division of Surveillance, Hazard Evaluations and Field Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio, USA.
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Liu F, Ichihara S, Mohideen SS, Sai U, Kitoh J, Ichihara G. Comparative study on susceptibility to 1-bromopropane in three mice strains. Toxicol Sci 2009; 112:100-10. [PMID: 19638432 DOI: 10.1093/toxsci/kfp173] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Previous studies indicate that 1-bromopropane (1BP) has neurotoxicity and reproductive toxicity both in humans and animals. The present study investigated strain differences in susceptibility to 1BP and identified possible biological factors that determine such susceptibility. Twenty-four male mice of each of the three strains (C57BL/6J, DBA/2J, and BALB/cA) were divided into four groups of six each and exposed to 1BP at 0, 50, 110, and 250 ppm for 8 h/day for 28 days by inhalation. At the end of exposure period, the relative susceptibilities of each strain to 1BP-mediated hepatotoxicity and male reproductive toxicity were evaluated. The contributing factors to strain-dependent susceptibility were assessed by determination of hepatic CYP2E1 levels, glutathione-S-transferase (GST) activity, glutathione (GSH) status, and NAD(P)H:quinone oxidoreductase and heme oxygenase-1 mRNA levels. Liver histopathology showed significantly larger area of liver necrosis and more degenerative lobules in BALB/cA in the order of BALB/cA > C57BL/6J > DBA/2J. BALB/cA showed higher CYP2E1 protein level and lower total GSH content and GST activity in the liver than DBA/2J. These results indicate that BALB/cA mice are the most susceptible to hepatotoxicity of 1BP among the three strains tested, and that CYP2E1, GSH level/GST activity may contribute to the susceptibility to 1BP hepatotoxicity. Exposure to > or = 50 ppm of 1BP also decreased sperm count and sperm motility and increased sperms with abnormal heads in all three strains mice in a dose-dependent manner. Comparison with previous studies in rats indicates that mice are far more susceptible than rats to 1BP regarding hepatotoxicity and reproductive toxicity.
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Affiliation(s)
- Fang Liu
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
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Yoshida Y, Nakano Y, Ueno S, Liu J, Fueta Y, Ishidao T, Kunugita N, Yanagihara N, Sugiura T, Hori H, Yamashita U. Effects of 1-bromopropane, a substitute for chlorofluorocarbons, on BDNF expression. Int Immunopharmacol 2009; 9:433-8. [PMID: 19189864 DOI: 10.1016/j.intimp.2009.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 12/31/2008] [Accepted: 01/13/2009] [Indexed: 10/21/2022]
Abstract
1-Bromopropane (1-BP) has been widely used as an alternative to ozone-depleting chlorofluorocarbons in various industries. Although the neurotoxicity of 1-BP has been recently reported, there is little information about the effect of 1-BP on the cells in brain by experimental approach. Here we studied the effect of 1-BP on brain-derived neurotrophic factor (BDNF) expression in astrocytes in vitro. The BDNF mRNA level was remarkably decreased by 1-BP in a human astrocytoma cell line, U251, and in mouse primary astrocytes. The DNA-binding and specific reporter activity of cAMP response element-binding transcription factor (CREB), which is one of the key molecules regulating BDNF expression, were reduced by 1-BP in U251 and/or mouse primary astrocytes. Additionally, protein kinase A (PKA) activity was suppressed by 1-BP in U251. These results suggest that BDNF expression was affected by 1-BP through at least PKA.
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Affiliation(s)
- Yasuhiro Yoshida
- Department of Immunology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan.
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Majersik JJ, Caravati EM, Steffens JD. Severe neurotoxicity associated with exposure to the solvent 1-bromopropane (n-propyl bromide). Clin Toxicol (Phila) 2008; 45:270-6. [PMID: 17453879 DOI: 10.1080/15563650701226218] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND 1-bromopropane was recently substituted for traditional ozone-depleting solvents in the industrial setting. CASE SERIES We report a cohort of six cases of 1-bromopropane neurotoxicity occurring in foam cushion gluers exposed to 1-bromopropane vapors from spray adhesives. Patients 1-5 were exposed 30-40 hours per week over three years; patient 6 had been employed for the previous three months. Exposure had peaked over the previous month when ventilatory fans were turned off. All patients complained of subacute onset of lower extremity pain or paresthesias. Five of six complained of difficulty walking and on examination had spastic paraparesis, distal sensory loss, and hyperreflexia. Three patients initially had nausea and headache. Serum bromide concentrations ranged from 44 to 170 mg/dL (reference 0-40 mg/dL). Apparent hyperchloremia was present with serum chloride concentrations of 105 to 139 mmol/L (reference 98-107 mmol/L). Air samples taken at the workplace during gluing operations revealed the mean air concentration of 1-bromopropane to be 130 ppm (range 91-176 ppm) with a seven hour time-weighted average of 108 ppm (range 92-127 ppm), well above the EPA-proposed limit of 25 ppm. Two years after exposure, the two most severely affected patients had minimal improvement of function and they, with a third patient, continued to experience chronic neuropathic pain. CONCLUSION This report supports the growing recognition of 1-bromopropane neurotoxicity in humans consisting most commonly of headache, nausea, and subacute spastic paraparesis with distal sensory loss. The pathogenesis of 1-BP neurotoxicity in humans has yet to be fully elucidated but may reflect a central distal axonopathy syndrome.
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Suda M, Honma T, Miyagawa M, Wang RS. Alteration of brain levels of neurotransmitters and amino acids in male F344 rats induced by three-week repeated inhalation exposure to 1-bromopropane. INDUSTRIAL HEALTH 2008; 46:348-359. [PMID: 18716383 DOI: 10.2486/indhealth.46.348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The present study investigated the effects of 1-bromopropane (1BP) on brain neuroactive substances of rats to determine the extent of its toxicity to the central nervous system (CNS). We measured the changes in neurotransmitters (acetylcholine, catecholamine, serotonin and amino acids) and their metabolites or precursors in eight brain regions after inhalation exposure to 1BP at 50 to 1,000 ppm for 8 h per day for 7 d per week for 3 wk. Rats were sacrificed at 2 h (Case 1), or at 19 h (Case 2) after the end of exposure. In Case 1, the level of 5-hydroxyindoleacetic acid (5HIAA) was lowered in some brain regions by 1BP exposure. The decrease of 5HIAA in the frontal cortex was statistically significant at 50 ppm 1BP exposure. In Case 2, gamma-amino butyric acid (GABA) and taurine were decreased in many brain regions of exposed rats, and a significant decrease of taurine in the midbrain occurred at 50 ppm 1BP exposure. In both cases of 2-h and 19-h intervals from the end of exposure to sacrifice, aspartate and glutamine levels were elevated in many brain regions, but the acetylcholine level did not change in any brain region. Three-week repeated exposure to 1BP produced significantly changes in amino acid contents of rat brains, particularly at 1,000 ppm.
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Affiliation(s)
- Megumi Suda
- National Institute of Occupational Safety and Health (JNIOSH),Kawasaki, Japan
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Han EH, Hwang YP, Lee KJ, Jeong TC, Jeong HG. 1-Bromopropane induces macrophage activation via extracellular signal-regulated kinase 1/2 MAPK and NF-κB pathways. Cancer Lett 2008; 262:28-36. [DOI: 10.1016/j.canlet.2007.11.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 11/20/2007] [Accepted: 11/20/2007] [Indexed: 11/28/2022]
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Banu S, Ichihara S, Huang F, Ito H, Inaguma Y, Furuhashi K, Fukunaga Y, Wang Q, Kitoh J, Ando H, Kikkawa F, Ichihara G. Reversibility of the Adverse Effects of 1-Bromopropane Exposure in Rats. Toxicol Sci 2007; 100:504-12. [PMID: 17890766 DOI: 10.1093/toxsci/kfm245] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Previous experiments indicated that 1-bromopropane (1-BP), an alternative to chloroflurocarbons, is neurotoxic and inhibits spermiation in the testis. Here we investigated the reversibility of the toxic effects of 1-BP in rats. Male Wistar rats were divided into three equal groups of 24 each and exposed by inhalation to 0, 400 or 1000 ppm of 1-BP for 6 weeks (8 hrs/day, 7 days/week). Eight rats from each group were sacrificed at the end of 6 weeks exposure, and at 4 and 14 weeks after the end of exposure, to assess the recovery processes. We studied sperm count, motility, morphology and testicular histopathology, as well as blood pressure, skin temperature and hindlimb muscle strength. At the end of 6 weeks of exposure to 1000 ppm (0 week recovery), testicular weight, epididymal weight, sperm count and motility were low, morphologically abnormal sperm were increased and spermatogenic cells showed diffuse degeneration. These changes did not show full recovery at 14 weeks recovery, with the exception of the prostate and seminal vesicular weights, which recovered back to control values. At 400 ppm, increased retained spermatids at 0 week recovery returned to normal at 4 weeks recovery. Exposure to 1000 ppm produced sustained reduction of hindlimb muscle strength at 14 weeks recovery, whereas normalization of the skin temperature and blood pressure was noted after transient changes. Our study showed that the effect of 1-BP on spermatogenesis is dose-dependent; low exposure inhibited spermiation and hormone-dependent organ weight reduction and these changes were transient, while a higher dose of 1000 ppm 1-BP caused persistent depletion of spermatogenic cells.
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Affiliation(s)
- Shameema Banu
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Raymond LW, Ford MD. Severe Illness in Furniture Makers Using a New Glue: 1-Bromopropane Toxicity Confounded by Arsenic. J Occup Environ Med 2007; 49:1009-19. [PMID: 17848857 DOI: 10.1097/jom.0b013e318145b616] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To describe the illnesses of four workers with high concentrations of serum bromide after exposure to glue containing 1-bromopropane (1-BP). METHODS We reviewed all available clinical records, examined the workers, and obtained additional urinary arsenic values. We used standard autoanalyzer and other routine methods for blood and urinalysis. RESULTS All four workers had symptoms and abnormal physical findings when hospitalized, remaining symptomatic with abnormal examinations 3 months later. Milder symptoms persisted in two workers, 8 years after their initial illnesses. Both have returned to work. Follow-up was unavailable for the other two workers. CONCLUSIONS Severe illness occurred in four gluers after 1-BP exposures associated with elevated levels of serum bromide. All had elevated urinary arsenic concentrations, the source of which remains unknown, but which confound interpretation of the abnormal bromide levels and clinical findings present during the acute illnesses.
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Affiliation(s)
- Lawrence W Raymond
- Carolinas Poison Center and Department of Family Medicine, Carolinas Medical Center, Charlotte, North Carolina 28232, USA.
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Fueta Y, Ishidao T, Ueno S, Yoshida Y, Kunugita N, Hori H. New approach to risk assessment of central neurotoxicity induced by 1-bromopropane using animal models. Neurotoxicology 2007; 28:270-3. [PMID: 16782201 DOI: 10.1016/j.neuro.2006.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Revised: 05/01/2006] [Accepted: 05/03/2006] [Indexed: 11/29/2022]
Abstract
1-Bromopropane (1-BP) induces central as well as peripheral neurotoxicity in workers. We have reported the dysfunction of feedback inhibition (i.e. disinhibition) in the rat hippocampus following exposure to 1-BP at concentrations of 1500 and 700 ppm. For risk assessment, we studied disinhibition of the CA1 region and the dentate gyrus in hippocampal slices obtained from control and 1-BP-exposed (200 and 400 ppm) rats, and determined the bromide concentration in the brain. Granule cell disinhibition was observed after inhalation exposure to 400 ppm 1-BP for 8 or 12 weeks, suggesting that the dentate gyrus was more sensitive than the CA1 region to 1-BP exposure. The lowest observed adverse effect level and the no observed adverse effect level of 1-BP inhalation for disinhibition were 400 and 200 ppm, respectively. The concentration of bromides in the brain increased from 2.9+/-1.5 to 85.0+/-25.4 microg/g-wet brain at week 4 of 400 ppm inhalation, and no further increase was observed even when the exposure period was extended for up to 12 weeks. The relationship between total dose (ppm-h) and the exposure concentration of 1-BP was investigated at different exposure concentrations. Disinhibition and death by inhalation depended on the total dose, and their occurrence appeared earlier as the exposure concentration increased. The results demonstrated a novel model for risk assessment of central neurotoxicity induced by 1-BP inhalation.
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Affiliation(s)
- Yukiko Fueta
- Department of Medical Technology I, School of Health Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishiku, Kitakyushu 807-8555, Japan.
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Lee SK, Jeon TW, Kim YB, Lee ES, Jeong HG, Jeong TC. Role of glutathione conjugation in the hepatotoxicity and immunotoxicity induced by 1-bromopropane in female BALB/c mice. J Appl Toxicol 2007; 27:358-67. [PMID: 17265426 DOI: 10.1002/jat.1214] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
1-Bromopropane (1-BP) is used as a cleaning agent or adhesive solvent in the workplace. In the present study, the hepatotoxic and immunotoxic effects of 1-bromopropane and its conjugation with glutathione (GSH) were investigated in female BALB/c mice. The animals were treated orally with 200, 500 and 1000 mg kg(-1) of 1-BP in corn oil for a dose response study or treated orally with 1000 mg kg(-1) of 1-BP for 6, 12, 24 and 48 h for a time course study. The hepatic and splenic contents of GSH were significantly decreased by 1-BP in a dose-dependent manner. S-propyl GSH was identified in livers following treatment with 1-BP by liquid chromatography-electrospray ionization tandem mass spectrometry. When the production of conjugates from 1-BP was investigated in livers following oral treatment with 1000 mg kg(-1) of 1-BP for 6, 12, 24 and 48 h, the GSH conjugates were detected maximally 6 h after treatment. Treatment of mice with 1-BP increased the serum activity of alanine aminotransferase dose-dependently. The oral 1-BP treatment significantly suppressed the antibody response to a T-dependent antigen and the production of splenic intracellular IL-2 in response to Con A in a dose-dependent manner. The present results suggested that 1-BP could cause hepatotoxicity and immunotoxicity as well as depletion of GSH content due to the formation of GSH conjugates.
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Affiliation(s)
- Sang Kyu Lee
- College of Pharmacy, Yeungnam University, Gyeongsan, 712-749, South Korea
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Furuhashi K, Kitoh J, Tsukamura H, Maeda KI, Wang H, Li W, Ichihara S, Nakajima T, Ichihara G. Effects of exposure of rat dams to 1-bromopropane during pregnancy and lactation on growth and sexual maturation of their offspring. Toxicology 2006; 224:219-28. [PMID: 16777312 DOI: 10.1016/j.tox.2006.04.044] [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: 03/29/2006] [Revised: 04/27/2006] [Accepted: 04/28/2006] [Indexed: 11/20/2022]
Abstract
1-Bromopropane (1-BP) exhibits neuroreproductive toxicities in adult rats and humans. Here, we determined the effects of exposure of rat dams to 1-BP during pregnancy and lactation on the growth and sexual maturation of their offspring. In Experiment 1, 40 rats were exposed to 0, 100, 400 and 800ppm 1-BP during pregnancy and lactation for 8h/day. Ten rats that were not placed in chambers throughout the experiment served to observe the effect of separation of dams from offspring. In Experiment 2, three groups of 10 pregnant rats each were exposed to fresh air in three chambers and 10 other rats were exposed to 800ppm 1-BP during pregnancy and lactation for 8h/day. After delivery, offspring of the exposed and non-exposed dams were swapped so that they were nursed by the opposite dams. In Experiment 1, the survival rate and body weight of offspring were lower than the non-exposed in 1-BP dose-dependent manner. In Experiment 2, the survival rate and body weight of offspring (Group A) nursed by exposed dams and those (Group B) of exposed dams were significantly lower than non-exposed groups. The body weight of Group A was lower than that of Group B, although the two groups showed a significant equal decrease in the survival rate. The number of dead offspring from Group A was significantly higher. Our results indicate that exposure to 1-BP during pregnancy and lactation has comparable effects on survival rate, but exposure during lactation has a more adverse effect on growth of offspring than that during pregnancy. Moreover, exposure during lactation is associated with reduced early survival of third generation (F2) rats.
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Affiliation(s)
- Koichi Furuhashi
- Department of Occupational and Environmental Health, Field of Social Life Science, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
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Yoshida Y, Liu JQ, Nakano Y, Ueno S, Ohmori S, Fueta Y, Ishidao T, Kunugita N, Yamashita U, Hori H. 1-BP inhibits NF-kappaB activity and Bcl-xL expression in astrocytes in vitro and reduces Bcl-xL expression in the brains of rats in vivo. Neurotoxicology 2006; 28:381-6. [PMID: 16815550 DOI: 10.1016/j.neuro.2006.05.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 04/04/2006] [Accepted: 05/23/2006] [Indexed: 01/15/2023]
Abstract
1-Bromopropane (1-BP) has been widely used as a substitute for chlorofluorocarbon that destroys the ozone layer. Although the central neurotoxicity of 1-BP has been recently reported, a molecular mechanism is not clear. In particular, the effects on cells in brain have not been fully analyzed. Here, we studied the effects of 1-BP on the activation of transcription factors involved in anti-apoptotic function or cell survival in astrocytes. Astrocytoma cell lines, U251, U373 and VM, or murine primary astrocytes were used for in vitro assay. DNA binding activities of NF-kappaB in these cells induced by interleukin (IL)-1 or LPS were inhibited by 1-BP. Consequently, the treatment of U251 cells with 1-BP resulted in suppression of NF-kappaB reporter activity. Furthermore, 1-BP blocked IkappaBalpha degradation, which is important for NF-kappaB activation. In addition, the level of Bcl-xL mRNA, which is known as an anti-apoptotic gene, were reduced in U251 treated with 1-BP or in the brain from rat exposed to 1-BP (400 ppm, 12 weeks). These results suggest that subchronic inhalation exposure to 1-BP vapor may affect the Bcl-xL expression in astrocytes.
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Affiliation(s)
- Y Yoshida
- Department of Immunology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Kitakyushu 807-8555, Japan.
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Toraason M, Lynch DW, DeBord DG, Singh N, Krieg E, Butler MA, Toennis CA, Nemhauser JB. DNA damage in leukocytes of workers occupationally exposed to 1-bromopropane. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2006; 603:1-14. [PMID: 16412685 DOI: 10.1016/j.mrgentox.2005.08.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2005] [Revised: 08/30/2005] [Accepted: 08/31/2005] [Indexed: 11/23/2022]
Abstract
1-bromopropane (1-BP; n-propyl bromide) (CAS No. 106-94-5) is an alternative to ozone-depleting chlorofluorocarbons that has a variety of potential applications as a degreasing agent for metals and electronics, and as a solvent vehicle for spray adhesives. Its isomer, 2-brompropane (2-BP; isopropyl bromide) (CAS No. 75-26-3) impairs antioxidant cellular defenses, enhances lipid peroxidation, and causes DNA damage in vitro. The present study had two aims. The first was to assess DNA damage in human leukocytes exposed in vitro to 1- or 2-BP. DNA damage was also assessed in peripheral leukocytes from workers with occupational exposure to 1-BP. In the latter assessment, start-of- and end-of-work week blood and urine samples were collected from 41 and 22 workers at two facilities where 1-BP was used as a solvent for spray adhesives in foam cushion fabrication. Exposure to 1-BP was assessed from personal-breathing zone samples collected for 1-3 days up to 8h per day for calculation of 8h time weighted average (TWA) 1-BP concentrations. Bromide (Br) was measured in blood and urine as a biomarker of exposure. Overall, 1-BP TWA concentrations ranged from 0.2 to 271 parts per million (ppm) at facility A, and from 4 to 27 ppm at facility B. The highest exposures were to workers classified as sprayers. 1-BP TWA concentrations were statistically significantly correlated with blood and urine Br concentrations. The comet assay was used to estimate DNA damage. In vitro, 1- or 2-BP induced a statistically significant increase in DNA damage at 1mM. In 1-BP exposed workers, start-of- and end-of-workweek comet endpoints were stratified based on job classification. There were no significant differences in DNA damage in leukocytes between workers classified as sprayers (high 1-BP exposure) and those classified as non-sprayers (low 1-BP exposure). At the facility with the high exposures, comparison of end-of-week values with start-of-week values using paired analysis revealed non-sprayers had significantly increased comet tail moments, and sprayers had significantly increased comet tail moment dispersion coefficients. A multivariate analysis included combining the data sets from both facilities, log transformation of 1-BP exposure indices, and the use of multiple linear regression models for each combination of DNA damage and exposure indices including exposure quartiles. The covariates were gender, age, smoking status, facility, and glutathione S-transferase M1 and T1 (GSTM1, GSTT1) polymorphisms. In the regression models, start-of-week comet tail moment in leukocytes was significantly associated with serum Br quartiles. End-of-week comet tail moment was significantly associated with 1-BP TWA quartiles, and serum Br quartiles. Gender, facility, and GSTM1 had a significant effect in one or more models. Additional associations were not identified from assessment of dispersion coefficients. In vitro and in vivo results provide limited evidence that 1-BP exposure may pose a small risk for increasing DNA damage.
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Affiliation(s)
- Mark Toraason
- National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226, USA.
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