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The Effects of the Inhalant Toluene on Cognitive Function and Behavioral Flexibility: A Review of Recent Findings. ADDICTION NEUROSCIENCE 2023; 5:100059. [PMID: 36798693 PMCID: PMC9928149 DOI: 10.1016/j.addicn.2022.100059] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Substance use disorder (SUD) is characterized, in part, by lack of control over drug seeking and taking. The prefrontal cortex (PFC) is highly involved in control of behavior and deficits in PFC structure and function have been demonstrated in clinical and preclinical studies of SUD. Of the various classes of drugs associated with the development of SUD, inhalants are among the least studied despite their widespread use among adolescents and children. In this work, we review what is currently known regarding the sites and mechanisms of action of inhalants with a focus on the volatile solvent toluene that is contained in a wide variety of legal and easily obtained products. We then describe how inhalants including toluene affect various behaviors with an emphasis on those associated with PFC function and how chronic use of inhalants alters brain structure and neuronal signaling. Findings from these studies highlight advances made in recent years that have expanded our understanding of the effects of inhalants on brain structure and reinforce the need for continued work in this field.
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Gao M, Teng W, Du Z, Nie L, An X, Liu W, Sun X, Shen Z, Shi A. Source profiles and emission factors of VOCs from solvent-based architectural coatings and their contributions to ozone and secondary organic aerosol formation in China. CHEMOSPHERE 2021; 275:129815. [PMID: 33639547 DOI: 10.1016/j.chemosphere.2021.129815] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/22/2021] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
Volatile organic compounds (VOCs) from solvent-based architectural coatings (SBACs) play an important role in photochemical air pollution with increasing consumption of architectural coatings in China. In this study, we collected 148 typical SBACs of 3 types in China. The TVOC emission factors and source profiles were established, the contributions of SBACs to ozone and secondary organic aerosol (SOA) formation were investigated. The VOC emissions and O3 and SOA amounts formed in chemical reactions from SBACs in 2017 were estimated. Key organic groups and VOC species with high reactivity were identified. According to the results, the TVOC emission factors were 507.17 g L-1 for solvent-based anticorrosive coatings, 381.34 g L-1 for solvent-based floor coatings and 459.68 g L-1 for solvent-based fire-retardant coatings. The VOC emissions were 186,902.11 t, 88,225.41 t and 71,352.32 t; the O3 amounts formed were 742,001.39 t, 397,896.60 t and 244,738.46 t; the SOA amounts formed were 3934.29 t, 2488.04 t and 1104.61 t, respectively, from 3 types of SBACs in 2017. The O3 production factors were 1781.82 g O3 (kg paint)-1, 1457.50 g O3 (kg paint)-1 and 1176.63 g O3 (kg paint)-1, the SOA production factors were 9.45 g SOA (kg paint)-1, 9.11 g SOA (kg paint)-1 and 5.31 g SOA (kg paint)-1, for 3 types of SBACs. Priority should be given to organic group of aromatics and top 17 VOC species with high reactivity for O3 and SOA eliminating strategies, especially three xylenes (o-xylene, m-xylene and p-xylene), ethylbenzene, trimethyl benzenes (1,3,5-trimethyl benzene, 1,2,3-Trimethyl benzene) and toluene.
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Affiliation(s)
- Meiping Gao
- Beijing Key Laboratory for VOCs Pollution Prevention and Treatment Technology and Application of Urban Air, National Engineering Research Center of Urban Environmental Pollution Control, Beijing Municipal Research Institute of Environmental Protection, Beijing, 100037, China.
| | - Wei Teng
- Appraisal Center for Environment & Engineering Ministry of Ecology and Environment, Beijing, 100012, China.
| | - Zhenxia Du
- College of Science, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Lei Nie
- Beijing Key Laboratory for VOCs Pollution Prevention and Treatment Technology and Application of Urban Air, National Engineering Research Center of Urban Environmental Pollution Control, Beijing Municipal Research Institute of Environmental Protection, Beijing, 100037, China.
| | - Xiaoshuan An
- Beijing Key Laboratory for VOCs Pollution Prevention and Treatment Technology and Application of Urban Air, National Engineering Research Center of Urban Environmental Pollution Control, Beijing Municipal Research Institute of Environmental Protection, Beijing, 100037, China.
| | - Wenwen Liu
- Beijing Key Laboratory for VOCs Pollution Prevention and Treatment Technology and Application of Urban Air, National Engineering Research Center of Urban Environmental Pollution Control, Beijing Municipal Research Institute of Environmental Protection, Beijing, 100037, China.
| | - Xuechun Sun
- College of Science, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Zhengchao Shen
- College of Science, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Aijun Shi
- Beijing Key Laboratory for VOCs Pollution Prevention and Treatment Technology and Application of Urban Air, National Engineering Research Center of Urban Environmental Pollution Control, Beijing Municipal Research Institute of Environmental Protection, Beijing, 100037, China.
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Cruz SL, Bowen SE. The last two decades on preclinical and clinical research on inhalant effects. Neurotoxicol Teratol 2021; 87:106999. [PMID: 34087382 DOI: 10.1016/j.ntt.2021.106999] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/24/2021] [Accepted: 05/18/2021] [Indexed: 12/21/2022]
Abstract
This paper reviews the scientific evidence generated in the last two decades on the effects and mechanisms of action of most commonly misused inhalants. In the first section, we define what inhalants are, how they are used, and their prevalence worldwide. The second section presents specific characteristics that define the main groups of inhalants: (a) organic solvents; (b) aerosols, gases, and volatile anesthetics; and (c) alkyl nitrites. We include a table with the molecular formula, structure, synonyms, uses, physicochemical properties and exposure limits of representative compounds within each group. The third and fourth sections review the direct acute and chronic effects of common inhalants on health and behavior with a summary of mechanisms of action, respectively. In the fifth section, we address inhalant intoxication signs and available treatment. The sixth section examines the health effects, intoxication, and treatment of nitrites. The seventh section reviews current intervention strategies. Finally, we propose a research agenda to promote the study of (a) solvents other than toluene; (b) inhalant mixtures; (c) effects in combination with other drugs of abuse; (d) age and (e) sex differences in inhalant effects; (f) the long-lasting behavioral effects of animals exposed in utero to inhalants; (g) abstinence signs and neurochemical changes after interrupting inhalant exposure; (h) brain networks involved in inhalant effects; and finally (i) strategies to promote recovery of inhalant users.
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Affiliation(s)
- Silvia L Cruz
- Department of Pharmacobiology, Center of Research and Advanced Studies (Cinvestav), Calzada de los Tenorios No. 235, Col. Granjas Coapa, México City 14330, México.
| | - Scott E Bowen
- Department of Psychology, Wayne State University, 5057 Woodward Ave., Suite 7906.1, Detroit, MI 48202, USA.
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Crossin R, Qama A, Andrews ZB, Lawrence AJ, Duncan JR. The effect of adolescent inhalant abuse on energy balance and growth. Pharmacol Res Perspect 2019; 7:e00498. [PMID: 31384470 PMCID: PMC6664821 DOI: 10.1002/prp2.498] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/21/2019] [Accepted: 05/25/2019] [Indexed: 12/20/2022] Open
Abstract
The abuse of volatile solvents such as toluene is a significant public health concern, predominantly affecting adolescents. To date, inhalant abuse research has primarily focused on the central nervous system; however, inhalants also exert effects on other organ systems and processes, including metabolic function and energy balance. Adolescent inhalant abuse is characterized by a negative energy balance phenotype, with the peak period of abuse overlapping with the adolescent growth spurt. There are multiple components within the central and peripheral regulation of energy balance that may be affected by adolescent inhalant abuse, such as impaired metabolic signaling, decreased food intake, altered dietary preferences, disrupted glucose tolerance and insulin release, reduced adiposity and skeletal density, and adrenal hypertrophy. These effects may persist into abstinence and adulthood, and the long-term consequences of inhalant-induced metabolic dysfunction are currently unknown. The signs and symptoms resulting from chronic adolescent inhalant abuse may result in a propensity for the development of adult-onset metabolic disorders such as type 2 diabetes, however, further research investigating the long-term effects of inhalant abuse upon energy balance and metabolism are needed. This review addresses several aspects of the short- and long-term effects of inhalant abuse relating to energy and metabolic processes, including energy balance, intake and expenditure; dietary preferences and glycemic control; and the dysfunction of metabolic homeostasis through altered adipose tissue, bone, and hypothalamic-pituitary-adrenal axis function.
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Affiliation(s)
- Rose Crossin
- Florey Institute of Neuroscience and Mental HealthParkvilleVIC
- Turning Point, Eastern HealthRichmondVIC
- Eastern Health Clinical SchoolMonash UniversityBox HillVIC
| | - Ashleigh Qama
- Florey Institute of Neuroscience and Mental HealthParkvilleVIC
- WHO Collaborating Centre for Viral HepatitisPeter Doherty Institute for Infection and ImmunityMelbourneVIC
| | - Zane B. Andrews
- Monash Biomedicine Discovery InstituteMonash UniversityClaytonVIC
| | - Andrew J. Lawrence
- Florey Institute of Neuroscience and Mental HealthParkvilleVIC
- Florey Department of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVIC
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Bell JS, DeLuca GC. Genes, smoking, and organic solvent exposure: An alarming cocktail for MS risk. Neurology 2018; 91:199-200. [PMID: 29970400 DOI: 10.1212/wnl.0000000000005896] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Jack S Bell
- From the University of Oxford Medical School (J.S.B.) and Nuffield Department of Clinical Neurosciences (G.C.D.), John Radcliffe Hospital, Oxford, UK
| | - Gabriele C DeLuca
- From the University of Oxford Medical School (J.S.B.) and Nuffield Department of Clinical Neurosciences (G.C.D.), John Radcliffe Hospital, Oxford, UK.
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Wang D, Yu H, Shao X, Yu H, Nie L. Direct and potential risk assessment of exposure to volatile organic compounds for primary receptor associated with solvent consumption. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 233:501-509. [PMID: 29102880 DOI: 10.1016/j.envpol.2017.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 09/12/2017] [Accepted: 10/04/2017] [Indexed: 06/07/2023]
Abstract
Rapid development of industrial production has stimulated the growth of consumption of raw and auxiliary materials including organic paints, among which volatile organic compounds (VOCs) are proved harmful to the population who inhale the polluted air based on epidemiologic studies. Therefore, new types of environment-friendly paints were developed to replace solvent-based paints (SBPs). Nevertheless, new types of paints containing VOCs failed to replace SBPs entirely due to certain disadvantages. Hence, five kinds of paints were employed in simulation experiments to assess the health risk of primary receptor including three kinds of water-based paints (WBPs) and two kinds of SBPs. Conclusions showed that mean TVOC concentration in breathing zone of primary receptor ranged from 9.5 to 13.6 mg/m3 and 3.4 × 103 to 1.4 × 104 mg/m3 for WBPs and SBPs, respectively. Assessments of non-cancer risk concluded that nearly one third quantified compounds exceeded corresponding thresholds for WBPs, and the maximum risk value was 101.33; for SBPs, the maximum risk value reached 50760.20, and twenty-two compounds exceeded the reference limits. The calculation of cancer risk values showed that seventeen compounds were higher than acceptable limit amongst which 1,2-dibromoethane had maximum values of 1.27 × 10-2 to 3.24 × 10-2 for WBPs; for SBPs, all quantified compounds exceeded the acceptable limit, and 82.61% VOCs were distributed in a scope larger than 1 × 10-3. Additionally, a removal efficiency of 60% was considered for primary receptor with personal protective equipment, and subsequent results confirmed its inability of lowering the risk resulted from hazardous VOCs. The calculated potential health risk could be applied to estimate the total health risk for both primary and secondary receptor based on consumed materials. The finding suggested that WBPs could improve VOCs exposure condition and reduce the direct and potential health risk significantly for primary receptor, although they might dissatisfy acceptable limit.
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Affiliation(s)
- Di Wang
- College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Han Yu
- College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Xia Shao
- National Engineering Research Center of Urban Environmental Pollution Control, Beijing Municipal Research Institute of Environment Protection, Beijing 100037, China
| | - Hongbing Yu
- College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
| | - Lei Nie
- National Engineering Research Center of Urban Environmental Pollution Control, Beijing Municipal Research Institute of Environment Protection, Beijing 100037, China
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Rivera-García MT, López-Rubalcava C, Cruz SL. Preclinical characterization of toluene as a non-classical hallucinogen drug in rats: participation of 5-HT, dopamine and glutamate systems. Psychopharmacology (Berl) 2015; 232:3797-808. [PMID: 26255180 DOI: 10.1007/s00213-015-4041-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 07/23/2015] [Indexed: 12/16/2022]
Abstract
RATIONALE Toluene is a misused inhalant with hallucinogenic properties and complex effects. Toluene blocks N-methyl-D-aspartate (NMDA) receptors, releases dopamine (DA), and modifies several neurotransmitter levels; nonetheless, the mechanism by which it produces hallucinations is not well characterized. OBJECTIVES This study aims (a) to study toluene's effects on the 5-HT2A-mediated head-twitch response (HTR), dopamine (DA), and serotonin (5-HT) tissue levels in discrete brain regions; (b) to compare the actions of toluene, ketamine, and 1-[2,5-dimethoxy-4-iodophenyl]-2-aminopropane (DOI) on HTR; and (c) to study the pharmacological blockade of toluene's and ketamine's effects by selective drugs. METHODS Independent groups of rats inhaled toluene (500-12,000 ppm) for 30 min during which the occurrence of serotonergic signs was analyzed. Brains were obtained after exposure to determine DA and 5-HT levels by HPLC. RESULTS Toluene concentration-dependently induced HTR. Other serotonin syndrome signs were evident at high concentrations. Toluene (4000 and 8000 ppm), and ketamine (3 and 10 mg/kg), significantly increased 5-HT levels in the frontal cortex (FC) striatum, hippocampus, and brain stem, as well as DA levels in the striatum and FC. Pretreatment with ketanserin (5HT2A/2C receptor antagonist), M100907 (selective 5-HT2A receptor antagonist), D-serine (co-agonist of the NMDA receptor glycine site), and haloperidol (D2 receptor antagonist) significantly decreased toluene's and ketamine's actions. The 5HT1A receptor antagonist WAY100635 had no effect. CONCLUSION Toluene stimulates 5HT2A and 5HT2C receptors, and increases 5-HT and DA levels. These actions are similar to those produced by ketamine and involve activation of a complex neurotransmitter network that includes NMDA receptor antagonism.
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Kobald SO, Wascher E, Blaszkewicz M, Golka K, van Thriel C. Neurobehavioral and neurophysiological effects after acute exposure to a single peak of 200 ppm toluene in healthy volunteers. Neurotoxicology 2015; 48:50-9. [DOI: 10.1016/j.neuro.2015.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 03/04/2015] [Accepted: 03/04/2015] [Indexed: 10/23/2022]
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Doi H. Pd-mediated rapid cross-couplings using [11C]methyl iodide: groundbreaking labeling methods in11C radiochemistry. J Labelled Comp Radiopharm 2015; 58:73-85. [DOI: 10.1002/jlcr.3253] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 11/28/2014] [Accepted: 11/28/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Hisashi Doi
- Labeling Chemistry Team; Division of Bio-Function Dynamics Imaging, RIKEN Center for Life Science Technologies (CLST); 6-7-3 Minatojima-minamimachi, Chuo-ku Kobe Hyogo 650-0047 Japan
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Suzuki M, Doi H, Koyama H, Zhang Z, Hosoya T, Onoe H, Watanabe Y. Pd0-Mediated Rapid Cross-Coupling Reactions, the RapidC-[11C]Methylations, Revolutionarily Advancing the Syntheses of Short-Lived PET Molecular Probes. CHEM REC 2014; 14:516-41. [DOI: 10.1002/tcr.201400002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Indexed: 11/12/2022]
Affiliation(s)
- Masaaki Suzuki
- National Center for Geriatrics and Gerontology; 35 Gengo Morioka-cho Obu-shi Aichi 474-8511 Japan
| | - Hisashi Doi
- Division of Bio-Function Dynamics Imaging; Riken Center for Life Science Technologies (CLST); 6-7-3 Minatojima-minamimachi Chuo-ku Kobe 650-0047 Japan
| | - Hiroko Koyama
- Division of Regeneration and Advanced Medical Science; Graduate School of Medicine; Gifu University; 1-1 Yanagido Gifu 501-1194 Japan
| | - Zhouen Zhang
- Division of Bio-Function Dynamics Imaging; Riken Center for Life Science Technologies (CLST); 6-7-3 Minatojima-minamimachi Chuo-ku Kobe 650-0047 Japan
| | - Takamitsu Hosoya
- Division of Regeneration and Advanced Medical Science; Graduate School of Medicine; Gifu University; 1-1 Yanagido Gifu 501-1194 Japan
| | - Hirotaka Onoe
- Division of Bio-Function Dynamics Imaging; Riken Center for Life Science Technologies (CLST); 6-7-3 Minatojima-minamimachi Chuo-ku Kobe 650-0047 Japan
| | - Yasuyoshi Watanabe
- Division of Bio-Function Dynamics Imaging; Riken Center for Life Science Technologies (CLST); 6-7-3 Minatojima-minamimachi Chuo-ku Kobe 650-0047 Japan
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Hester SD, Johnstone AF, Boyes WK, Bushnell PJ, Shafer TJ. Acute toluene exposure alters expression of genes in the central nervous system associated with synaptic structure and function. Neurotoxicol Teratol 2011; 33:521-9. [DOI: 10.1016/j.ntt.2011.07.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 07/07/2011] [Accepted: 07/20/2011] [Indexed: 10/17/2022]
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Binge toluene exposure alters glutamate, glutamine and GABA in the adolescent rat brain as measured by proton magnetic resonance spectroscopy. Drug Alcohol Depend 2011; 115:101-6. [PMID: 21126832 PMCID: PMC3071441 DOI: 10.1016/j.drugalcdep.2010.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 09/07/2010] [Accepted: 11/01/2010] [Indexed: 12/23/2022]
Abstract
Despite the high incidence of toluene abuse in adolescents, little is known regarding the effect of binge exposure on neurochemical profiles during this developmental stage. In the current study, the effects of binge toluene exposure during adolescence on neurotransmitter levels were determined using high-resolution proton magnetic resonance spectroscopy ex vivo at 11.7T. Adolescent male Sprague-Dawley rats were exposed to toluene (0, 8000, or 12,000 ppm) for 15 min twice daily from postnatal day 28 (P28) through P34 and then euthanized either 1 or 7 days later (on P35 or P42) to assess glutamate (GLU), glutamine, and GABA levels in intact tissue punches from the medial prefrontal cortex (mPFC), anterior striatum and hippocampus. In the mPFC, toluene reduced GLU 1 day after exposure, with no effect on GABA, while after 7 days, GLU was no longer affected but there was an increase in GABA levels. In the hippocampus, neither GABA nor GLU was altered 1 day after exposure, whereas 7 days after exposure, increases were observed in GABA and GLU. Striatal GLU and GABA levels measured after either 1 or 7 days were not altered after toluene exposure. These findings show that 1 week of binge toluene inhalation selectively alters these neurotransmitters in the mPFC and hippocampus in adolescent rats, and that some of these effects endure at least 1 week after the exposure. The results suggest that age-dependent, differential neurochemical responses to toluene may contribute to the unique behavioral patterns associated with drug abuse among older children and young teens.
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Abstract
Toluene is an organic solvent that is widely used by industry and is ubiquitous in our environment. As a result, exposure to solvents like toluene in work-related settings (i.e., relatively constant, low-level exposures) or through inhalant abuse (i.e., relatively intermittent, high-level exposures) is increasing for many women of reproductive age. Evidence suggests that the risk for pregnancy problems, as well as developmental delays and neurobehavioral difficulties, is higher for the children of women who have been exposed to high concentrations of organic solvents during pregnancy than for those who have not. These risks appear to be higher in cases of abuse exposure to solvents such as toluene, particularly in comparison to the risk for teratogenic outcomes with occupational solvent exposure. Despite this, the reproductive toxicology and teratology following abuse of toluene and other inhalants remains under-investigated. This brief review describes the current state of our understanding of the reproductive and teratogenic risk of gestational toluene abuse. The data to date suggest that the high levels of toluene exposure typical with inhalant abuse are more detrimental to fetal development than typical occupational exposure, and preclinical paradigms can be beneficial for investigating the processes and risks of prenatal solvent exposure. While substantial research has been done on the reproductive effects of occupational exposures to organic solvents, more research is needed on the outcomes and mechanisms of exposures typical of inhalant abuse.
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Affiliation(s)
- John H Hannigan
- Merrill Palmer Skillman Institute, Department of Obstetrics & Gynecology, C.S. Mott Center for Human Growth & Development, Wayne State University, Detroit, MI 48202, USA.
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Brain damage in a large cohort of solvent abusers. Acta Neuropathol 2010; 119:435-45. [PMID: 20300918 DOI: 10.1007/s00401-010-0653-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 02/05/2010] [Accepted: 02/06/2010] [Indexed: 10/19/2022]
Abstract
The neuropathology of solvent inhalation consists of patchy myelin loss with white matter macrophages that contain granular inclusions. It has been described only in a small number of cases. We sought to characterize the abnormalities in greater detail. In a retrospective study from 1995 to 2009, we encountered 88 autopsy cases with documented history of solvent abuse by inhalation and 1 with industrial exposure. Among these are 6 fetuses and infants with maternal exposure, 23 children (12-17 years), and 60 adults (18-66 years). Available brain samples from 75 cases were stained with solochrome cyanein (to demonstrate myelin) and periodic acid-Schiff (PAS) (to highlight the inclusions). Forty brains of ethanol and/or illicit drug exposed individuals and ten cases of multiple sclerosis were examined as controls. We found that 16 cases (age 23-49, median 37 years) had well-established leukoencephalopathy with multifocal myelin loss and abundant macrophages that stain with PAS and which contain birefringent inclusions. Six cases (age 15-55, median 27 years) had early leukoencephalopathy with scattered macrophages but no obvious myelin changes. Clusters of PAS-staining but non-birefringent macrophages were seen in 2/10 cases of (active) multiple sclerosis and in none of the ethanol/drug exposed brains. Ultrastructurally, inclusions from solvent cases differed from multiple sclerosis cases. Although exposure to solvents is impossible to quantify, there appears to be a duration-dependent effect. Brain damage related to solvent abuse can begin within only a few years of the onset. In the context of substance abuse, the changes are relatively specific for solvent inhalation and do not appear to result from demyelination alone. Interaction with ethanol cannot be excluded as a compounding risk factor.
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Suzuki M, Doi H. Pd0-Mediated Rapid C-[11C]Methylations and C-[18F]Fluoromethylations: Revolutionary New Methodologies for the Synthesis of Short-Lived PET Molecular Probes. J SYN ORG CHEM JPN 2010. [DOI: 10.5059/yukigoseikyokaishi.68.1195] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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O'Leary-Moore SK, Galloway MP, McMechan AP, Irtenkauf S, Hannigan JH, Bowen SE. Neurochemical changes after acute binge toluene inhalation in adolescent and adult rats: a high-resolution magnetic resonance spectroscopy study. Neurotoxicol Teratol 2009; 31:382-9. [PMID: 19628036 DOI: 10.1016/j.ntt.2009.07.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 06/12/2009] [Accepted: 07/13/2009] [Indexed: 11/26/2022]
Abstract
Inhalant abuse in young people is a growing public health concern. We reported previously that acute toluene intoxication in young rats, using a pattern of exposures that approximate abuse patterns of inhalant use in humans, significantly altered neurochemical measures in select brain regions. In this study, adolescent and young adult rats were exposed similarly to an acute (2 x 15 min), high dose (8000-12,000 ppm) of toluene and high-resolution magic angle spinning proton magnetic resonance spectroscopy (HR-MAS 1H-MRS) was used to assess neurochemical profiles of tissue samples from a number of brain regions collected immediately following solvent exposure. The current investigation focused on N-acetyl-aspartate (NAA), choline-containing compounds, creatine, glutamate, GABA, and glutamine. Contrary to our predictions, no significant alterations were found in the levels of NAA, choline, creatine, glutamate, or glutamine in adolescent animals. In contrast to these minimal effects in adolescents, binge toluene exposure altered several neurochemical parameters in young adult rats, including decreased levels of choline and GABA in the frontal cortex and striatum and lowered glutamine and NAA levels in the frontal cortex. One of the more robust findings was a wide-ranging increase in lactate after toluene exposure in adult animals, an effect not observed in adolescents. These age-dependent effects of toluene are distinct from those reported previously in juvenile rats and suggest a developmental difference in vulnerability to the effects of inhalants. Specifically, the results suggest that the neurochemical response to toluene in adolescents is attenuated compared to adults, and imply an association between these neurochemical differences and age-influenced differences in solvent abuse in humans.
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Shelton KL, Slavova-Hernandez G. Characterization of an inhaled toluene drug discrimination in mice: effect of exposure conditions and route of administration. Pharmacol Biochem Behav 2009; 92:614-20. [PMID: 19268500 DOI: 10.1016/j.pbb.2009.02.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 02/17/2009] [Accepted: 02/25/2009] [Indexed: 01/05/2023]
Abstract
The drug discrimination procedure in animals has been extensively utilized to model the abuse related, subjective effects of drugs in humans, but it has seldom been used to examine abused volatile inhalants like toluene. The present study sought to characterize the temporal aspects of toluene's discriminative stimulus as well assess toluene blood concentrations under identical exposure conditions. B6SJLF1/J mice were trained to discriminate 10 min of exposure to 6000 ppm inhaled toluene vapor from air. Toluene vapor concentration dependently substituted for the training exposure condition with longer exposures to equivalent concentrations producing greater substitution than shorter exposures. Toluene's discriminative stimulus effects dissipated completely by 60 min after the cessation of exposure. Injected liquid toluene dose-dependently substituted for toluene vapor as well as augmenting the discriminative stimulus effects of inhaled toluene. Toluene blood concentrations measured under several exposure conditions which produced full substitution were all nearly identical suggesting that the concentration of toluene in the animal tissues at the time of testing determined discriminative performance. These results indicate that the discriminative stimulus effects of inhaled toluene vapor are likely mediated by CNS effects rather than by its pronounced peripheral stimulus effects.
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Affiliation(s)
- Keith L Shelton
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298-0613, USA.
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Schiffer WK, Liebling CN, Patel V, Dewey SL. Targeting the treatment of drug abuse with molecular imaging. Nucl Med Biol 2007; 34:833-47. [DOI: 10.1016/j.nucmedbio.2007.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Revised: 04/30/2007] [Accepted: 05/12/2007] [Indexed: 11/25/2022]
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19
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Riegel AC, Zapata A, Shippenberg TS, French ED. The abused inhalant toluene increases dopamine release in the nucleus accumbens by directly stimulating ventral tegmental area neurons. Neuropsychopharmacology 2007; 32:1558-69. [PMID: 17213847 DOI: 10.1038/sj.npp.1301273] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Recreational abuse of toluene-containing volatile inhalants by adolescents is a significant public health problem. The mechanisms underlying the abuse potential of such substances remain unclear, but could involve increased activity in mesoaccumbal dopamine (DA) afferents innervating the nucleus accumbens (ACB). Here, using in vitro electrophysiology, we show that application of behaviorally relevant concentrations of toluene directly stimulates DA neurons in the ventral tegmental area (VTA), but not surrounding midbrain regions. Toluene stimulation of VTA neurons persists when synaptic transmission is reduced. Moreover, unlike non-DA neurons, the magnitude of VTA DA neuron firing does not decline during longer exposures designed to emulate 'huffing'. Using dual-probe in vivo microdialysis, we show that perfusion of toluene directly into the VTA increases DA concentrations in the VTA (somatodendritic release) and its terminal projection site, the ACB. These results provide the first demonstration that even brief exposure to toluene increases action potential drive onto mesoaccumbal VTA DA neurons, thereby enhancing DA release in the ACB. The finding that toluene stimulates mesoaccumbal neurotransmission by activating VTA DA neurons directly (independently of transynaptic inputs) provide insights into the neural substrates that may contribute to the initiation and pathophysiology of toluene abuse.
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Affiliation(s)
- Arthur C Riegel
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, USA.
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20
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O'Leary-Moore SK, Galloway MP, McMechan AP, Hannigan JH, Bowen SE. Region-dependent alterations in glutamate and GABA measured by high-resolution magnetic resonance spectroscopy following acute binge inhalation of toluene in juvenile rats. Neurotoxicol Teratol 2007; 29:466-75. [PMID: 17466488 DOI: 10.1016/j.ntt.2007.03.062] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Revised: 02/14/2007] [Accepted: 03/16/2007] [Indexed: 11/19/2022]
Abstract
Little is known about the neurochemical effects accompanying the high-concentration inhalant exposures characteristic of binge solvent abuse. In adult animals, prior studies with other patterns of exposure indicate that toluene, a commonly abused household and industrial solvent, has significant effects on the glutamatergic and GABAergic neurotransmitter systems and on other neurotransmitter systems as well. In the current investigation, high-resolution "magic angle" spinning proton magnetic resonance spectroscopy (HR-MAS (1)H-MRS) was used to assess the effect of acute binge toluene inhalation on regional brain concentrations of various neurochemicals including glutamate (GLU), GABA, and glutamine (GLN) in juvenile male and female rats. Acute toluene (8000 ppm or 12,000 ppm) significantly reduced levels of hippocampal GABA (-12%) and GLU (-8%), and the GLU/GLN ratio, an index of glutamatergic tone, was significantly reduced (-22%) in the dorsal anterior striatum, driven largely by a 28% increase in GLN. Significant increases in alanine and lactate in several brain regions after acute toluene may be indicative of altered oxygen-dependent metabolism associated with the inhalation of higher concentrations of toluene (e.g., >5000 ppm). Other components of the MR-visible neurochemical profile, such as N-acetylaspartate (NAA), myo-inositol, creatine, and various choline containing compounds, were unchanged by acute toluene. The results are consistent with the notion that binge toluene exposure affects juvenile neurochemistry in systems mediating the rewarding and emotional aspects of substance abuse. Moreover the results provide a framework to understand further (1)H-MRS studies in clinical populations.
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Affiliation(s)
- S K O'Leary-Moore
- Department of Psychology, Wayne State University, Detroit, MI 48201, United States
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21
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Oshiro WM, Krantz QT, Bushnell PJ. Repeated inhalation of toluene by rats performing a signal detection task leads to behavioral tolerance on some performance measures. Neurotoxicol Teratol 2007; 29:247-54. [PMID: 17175136 DOI: 10.1016/j.ntt.2006.11.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 10/17/2006] [Accepted: 11/02/2006] [Indexed: 11/22/2022]
Abstract
Previous work showed that trichloroethylene (TCE) impairs sustained attention as evidenced by a reduction in accuracy and elevation of response latencies in rats trained to perform a visual signal detection task (SDT). This work also showed that these effects abate during repeated exposures if rats inhale TCE while performing the SDT. The present experiment sought to determine whether toluene, another commonly-used solvent, would induce tolerance similarly if inhaled repeatedly during SDT testing. Sixteen male, Long-Evans rats were trained to perform the SDT. Upon completion of training, rats were divided into 2 groups. In Phase I, concentration-effect functions were determined for toluene (0, 1200, 1600, 2000, 2400 ppm) in both groups. Toluene reduced the proportion of correct responses [P(correct)], and increased response time (RT) and response failures. In Phase II, Group-Tol inhaled 1600 ppm toluene while Group-Air inhaled clean air during 11 daily SDT sessions. In Group-Tol the effect of toluene on P(correct) abated after 3 days, while RT remained elevated for the duration of the repeated exposures. In Phase III, toluene concentration-effect functions were re-determined for both groups. Group-Air remained impaired on all test measures, whereas for Group-Tol, toluene did not reduce P(correct), but continued to increase RT. These data confirm our previous hypothesis that animals can develop tolerance to chemical exposures that impair appetitively-motivated behaviors if that impairment leads to loss of reinforcement.
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Affiliation(s)
- Wendy M Oshiro
- Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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22
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Schiffer WK, Lee DE, Alexoff DL, Ferrieri R, Brodie JD, Dewey SL. Metabolic correlates of toluene abuse: decline and recovery of function in adolescent animals. Psychopharmacology (Berl) 2006; 186:159-67. [PMID: 16703400 DOI: 10.1007/s00213-006-0359-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Accepted: 02/21/2006] [Indexed: 10/24/2022]
Abstract
RATIONALE Children and adolescents will readily abuse household products that contain solvents such as toluene. It is likely that reinforcing exposures to toluene alter brain glucose metabolism. OBJECTIVE Using an animal model of drug reinforcement, we sought to identify a metabolic signature of toluene abuse in the adolescent rodent brain. Small animal PET (microPET), in combination with the glucose analog radiotracer, (18)FDG, were used to evaluate the metabolic consequences of inhaled toluene. METHODS The exposure protocol paralleled our previously established method for assessing the conditioned reinforcing effects of toluene (5,000 ppm) using the conditioned place preference (CPP) paradigm. Animals were scanned at baseline and 2 h after the last exposure. Follow-up (18)FDG scans occurred 1 day, 3 weeks, and 2 months later. RESULTS After six pairings, 38% of the animals preferred the toluene paired chamber and 25% were averse. The immediate metabolic effect in toluene-exposed animals was a 20% decline in whole brain (18)FDG uptake. Twenty-four hours following the last exposure, the whole brain decline was 40%, and 2 months later, the decline was 30% of pretoluene levels. A region-by-region analysis demonstrated significant additional decreases in the pons, cerebellum, striatum, midbrain, temporal cortex, and hippocampus. Two months after toluene cessation, regions of complete metabolic recovery were the thalamus and cerebellum; however, the temporal cortex did not recover. CONCLUSIONS Brain uptake of (18)FDG appears to be a useful tool for examining the metabolic impact of toluene abuse, which include a profound decline followed by region-specific recovery after cessation.
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Affiliation(s)
- Wynne K Schiffer
- Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
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23
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Gerasimov MR, Ferrieri RA, Pareto D, Logan J, Alexoff D, Ding YS. Synthesis and evaluation of inhaled [11C]butane and intravenously injected [11C]acetone as potential radiotracers for studying inhalant abuse. Nucl Med Biol 2005; 32:201-8. [PMID: 15721766 DOI: 10.1016/j.nucmedbio.2004.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2004] [Revised: 10/22/2004] [Accepted: 11/10/2004] [Indexed: 11/15/2022]
Abstract
The phenomenon of inhalant abuse is a growing problem in the US and many countries around the world. Yet, relatively little is known about the pharmacokinetic properties of inhalants that underlie their abuse potential. While the synthesis of 11C-labeled toluene, acetone and butane has been proposed in the literature, none of these compounds has been developed as radiotracers for PET studies. In the present report we extend our previous studies with [11C]toluene to include [11C]acetone and [11C]butane with the goal of comparing the pharmacokinetic profiles of these three volatile abused substances. Both [11C]toluene and [11C]acetone were administered intravenously and [11C]butane was administered via inhalation to anesthesized baboons. Rapid and efficient uptake of radiolabeled toluene and acetone into the brain was followed by fast clearance in the case of toluene and slower kinetics in the case of acetone. [11C]Butane was detected in the blood and brain following inhalation, but the levels of radioactivity in both tissues dropped to half of the maximal values over the period of less than a minute. To our knowledge, this is the first reported study of the in vivo brain pharmacokinetics of labeled acetone and butane in nonhuman primates. These data provide insight into the pharmacokinetic features possibly associated with the abuse liability of toluene, acetone and butane.
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Affiliation(s)
- Madina R Gerasimov
- Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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24
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Abstract
Neurochemical imaging studies can identify molecular targets of abused drugs and link them to the underlying pathology associated with behaviors such as drug dependence, addiction and withdrawal. positron emission tomography (PET) is opening new avenues for the investigation of the neurochemical disturbances underlying drug abuse and addiction and the in vivo mechanisms by which medications might ameliorate these conditions. PET can identify vulnerable human populations, treatment strategies and monitor treatment efficacy. Thus, with this tool and the knowledge it provides, the potential for developing novel drugs and treatment strategies for drug addiction is now close at hand.
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Affiliation(s)
- Wynne K Schiffer
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794, USA.
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25
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Rapid methylation on carbon frameworks leading to the synthesis of a PET tracer capable of imaging a novel CNS-type prostacyclin receptor in living human brain. Trends Analyt Chem 2004. [DOI: 10.1016/j.trac.2004.06.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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26
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Takebayashi K, Sekine Y, Takei N, Minabe Y, Isoda H, Takeda H, Nishimura K, Nakamura K, Suzuki K, Iwata Y, Sakahara H, Mori N. Metabolite alterations in basal ganglia associated with psychiatric symptoms of abstinent toluene users: a proton MRS study. Neuropsychopharmacology 2004; 29:1019-26. [PMID: 15039764 DOI: 10.1038/sj.npp.1300426] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Long-term toluene abuse causes a variety of psychiatric symptoms. However, little is known about abnormalities at the neurochemical level in the living human brain after long-term exposure to toluene. To detect neurochemical changes in the basal ganglia of subjects with a history of long-term toluene use, proton magnetic resonance spectroscopy (1H MRS) was performed in 12 abstinent toluene users and 13 healthy comparisons with no history of drug abuse. N-acetylaspartate (NAA), creatine plus phosphocreatine (Cr + PCr), choline-containing compounds (Cho), and myo-inositol (MI) levels were measured in the left and right basal ganglia. The Cho/Cr + PCr ratio, a marker of membrane metabolism, was significantly increased in the basal ganglia of toluene users in comparison to that of the control subjects. Furthermore, the increase in the Cho/Cr + PCr ratio was significantly correlated with the severity of residual psychiatric symptoms. These findings suggest that long-term toluene use causes membrane disturbance in the basal ganglia, which is associated with residual psychiatric symptoms that persist even after long-term abstinence from toluene use.
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Affiliation(s)
- Kiyokazu Takebayashi
- Department of Psychiatry and Neurology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
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27
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Lee DE, Schiffer WK, Dewey SL. Gamma-vinyl GABA (vigabatrin) blocks the expression of toluene-induced conditioned place preference (CPP). Synapse 2004; 54:183-5. [PMID: 15459943 DOI: 10.1002/syn.20072] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Dianne E Lee
- Medical Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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28
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Gerasimov MR, Collier L, Ferrieri A, Alexoff D, Lee D, Gifford AN, Balster RL. Toluene inhalation produces a conditioned place preference in rats. Eur J Pharmacol 2003; 477:45-52. [PMID: 14512097 DOI: 10.1016/j.ejphar.2003.08.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Toluene is a widely abused solvent with demonstrated addictive potential in humans. Here we explore if conditioned place preference can be used to study the abuse-related effects of inhaled toluene in rats. Animals were confined to a distinctive compartment of a three-compartment chamber while exposed to toluene vapor and later tested for preference for that compartment compared to appropriate control subjects. In this study, a flame ionization detector was used for on-line monitoring of toluene vapor concentrations inside the conditioning apparatus coupled with computerized recording of the time spent by the animals on the test day in each of the chambers. Sprague-Dawley rats were exposed to 810, 1895 or 4950 ppm of toluene vapors in either the black or white compartment during 30-min pairing sessions given every other day alternating with air exposure for the total of six pairings for each treatment. Rats that received air in both sides (control group) did not show any preference for either side with approximately equal time spent in each compartment on the test day (241 +/- 33 and 234 +/- 34 s, for white and black box, respectively). However, the 1895- and 4950-ppm test groups, but not the 810-ppm group, demonstrated a significant preference for the side paired with toluene exposure. When a subsequent test session was performed during toluene exposures, no conditioned place preference was observed. Thus, toluene produced a clear conditioned place preference that appears to be most evident when animals are not intoxicated. This procedure should be useful for further studies of the abuse-related effects of abused inhalants.
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Affiliation(s)
- Madina R Gerasimov
- Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
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29
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Abstract
Acute effects of the abused inhalant toluene resemble those of CNS depressant drugs. Since abuse of toluene involves repeated use, the purpose of the present study was to evaluate the effects of repeated or continuous exposure to toluene and to compare these effects to those of other inhalants and depressants. In experiment 1, ICR mice exposed continuously to 250 ppm toluene via inhalation for four days developed mild dependence upon termination that was characterized by an increase in severity of handling-induced convulsions. However, administration of the convulsants, N-methyl-D-aspartate (NMDA) or pentylenetetrazole (PTZ), did not differentially affect toluene- vs. air-exposed mice. In experiment 2, CFW mice (but not ICR mice) developed cross-sensitization to the initial locomotor stimulatory effects of toluene following four days of injections with 10 mg/kg/day diazepam. Previous findings have shown that 1,1,1-trichloroethane (TCE) produced robust dependence and cross-sensitization to diazepam's locomotor effects when tested under similar conditions. The present results suggest that the dependence and cross-sensitization with diazepam produced by toluene are milder than those induced by TCE. Further, these studies add to increasing evidence that abused inhalants do not have identical pharmacological effects.
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Affiliation(s)
- Jenny L Wiley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, P.O. Box 980613, Richmond, VA 23298-0613, USA.
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30
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Volkow ND, Fowler JS, Wang GJ. Positron emission tomography and single-photon emission computed tomography in substance abuse research. Semin Nucl Med 2003; 33:114-28. [PMID: 12756644 DOI: 10.1053/snuc.2003.127300] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Many advances in the conceptualization of addiction as a disease of the brain have come from the application of imaging technologies directly in the human drug abuser. New knowledge has been driven by advances in radiotracer design and chemistry and positron emission tomography (PET) and single-photon emission computed tomography (SPECT) instrumentation and the integration of these scientific tools with the tools of biochemistry, pharmacology, and medicine. This topic cuts across the medical specialties of neurology, psychiatry, oncology, and cardiology because of the high medical, social, and economic toll that drugs of abuse, including the legal drugs, cigarettes and alcohol, take on society. This article highlights recent advances in the use of PET and SPECT imaging to measure the pharmacokinetic and pharmacodynamic effects of drugs of abuse on the human brain.
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Affiliation(s)
- Nora D Volkow
- Brookhaven National Laboratory, Upton, NY 11973, USA
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31
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Ferrieri RA. Supercritical fluids in medical radioisotope processing and chemistry, Part II: Applications - real and demonstrated. J Labelled Comp Radiopharm 2003. [DOI: 10.1002/jlcr.732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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32
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Gerasimov MR, Logan J, Ferrieri RA, Muller RD, Alexoff D, Dewey SL. Effect of vehicle on brain uptake of [11C]toluene. Nucl Med Biol 2002; 29:607-12. [PMID: 12088732 DOI: 10.1016/s0969-8051(02)00315-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
With the goal of investigating the pharmacokinetics of the abused solvent, toluene we have adapted the rapid coupling of methyl iodide with tributylphenylstannane mediated by palladium(0) complex to the synthesis of no-carrier-added [11C]toluene starting with 11CH(3)I. Two methods for purification and formulation of the tracer were developed. The first one yielded [11C]toluene dissolved in dimethylacetamide/saline solution, for the second one we adapted supercritical fluid technology where the tracer was purified using and conventional C(18) HPLC column and pure supercritical CO(2) fluid as a mobile phase operating at 2000 psi. Formulation of the tracer in cyclodextrin resulted in a significantly higher integrated uptake and distribution volume values. Additionally, we observed higher uptake and slower clearance of 11C-toluene in white matter, consistent with higher lipid content and neurotoxicological evidence indicating restricted and diffuse white matter changes in toluene abusers. This trend was observed when either DMA or cyclodextrin was used as a vehicle. It appears then, that the choice of a vehicle affected only the degree of bioavailability, but not the regional brain pharmacokinetics. Finally, we demonstrated the effect of a decreased percent difference between DV values for the studies performed on the same day, that is, test/retest variability was lower for all brain regions in beta-cyclodextrin experiments. Present results clearly demonstrate that the choice of a vehicle has a significant effect on tracer uptake and should be considered as a potential factor contributing to the pharmacokinetic measurements.
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Affiliation(s)
- Madina R Gerasimov
- Brookhaven National Laboratory, Department of Chemistry, Upton, NY 11973, USA.
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