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Lin K, Wallis C, Wong EM, Edwards P, Cole A, Van Winkle L, Wexler AS. Heterogeneous deposition of regular and mentholated little cigar smoke in the lungs of Sprague-Dawley rats. Part Fibre Toxicol 2023; 20:42. [PMID: 37932763 PMCID: PMC10626780 DOI: 10.1186/s12989-023-00554-6] [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] [Received: 08/14/2023] [Accepted: 10/31/2023] [Indexed: 11/08/2023] Open
Abstract
BACKGROUND Quantifying the dose and distribution of tobacco smoke in the respiratory system is critical for understanding its toxicity, addiction potential, and health impacts. Epidemiologic studies indicate that the incidence of lung tumors varies across different lung regions, suggesting there may be a heterogeneous deposition of smoke particles leading to greater health risks in specific regions. Despite this, few studies have examined the lobar spatial distribution of inhaled particles from tobacco smoke. This gap in knowledge, coupled with the growing popularity of little cigars among youth, underscores the need for additional research with little cigars. RESULTS In our study, we analyzed the lobar deposition in rat lungs of smoke particles from combusted regular and mentholated Swisher Sweets little cigars. Twelve-week-old male and female Sprague-Dawley rats were exposed to smoke particles at a concentration of 84 ± 5 mg/m3 for 2 h, after which individual lung lobes were examined. We utilized Inductively Coupled Plasma Mass Spectrometry to quantify lobar chromium concentrations, serving as a smoke particle tracer. Our findings demonstrated an overall higher particle deposition from regular little cigars than from the mentholated ones. Higher particle deposition fraction was observed in the left and caudal lobes than other lobes. We also observed sex-based differences in the normalized deposition fractions among lobes. Animal study results were compared with the multi-path particle dosimetry (MPPD) model predictions, which showed that the model overestimated particle deposition in certain lung regions. CONCLUSIONS Our findings revealed that the particle deposition varied between different little cigar products. The results demonstrated a heterogenous deposition pattern, with higher particle deposition observed in the left and caudal lobes, especially with the mentholated little cigars. Additionally, we identified disparities between our measurements and the MPPD model. This discrepancy highlights the need to enhance the accuracy of models before extrapolating animal study results to human lung deposition. Overall, our study provides valuable insights for estimating the dose of little cigars during smoking for toxicity research.
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Affiliation(s)
- Kaisen Lin
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, 48824, USA.
- Air Quality Research Center, University of California, Davis, Davis, CA, 95616, USA.
| | - Christopher Wallis
- Air Quality Research Center, University of California, Davis, Davis, CA, 95616, USA
| | - Emily M Wong
- Air Quality Research Center, University of California, Davis, Davis, CA, 95616, USA
| | - Patricia Edwards
- Center for Health and the Environment, University of California, Davis, Davis, CA, 95616, USA
| | - Austin Cole
- UC Davis Interdisciplinary Center for Plasma Mass Spectrometry, University of California, Davis, Davis, CA, 95616, USA
| | - Laura Van Winkle
- Department of Anatomy, Physiology and Cell Biology, University of California, Davis, Davis, CA, 95616, USA
- Center for Health and the Environment, University of California, Davis, Davis, CA, 95616, USA
| | - Anthony S Wexler
- Air Quality Research Center, University of California, Davis, Davis, CA, 95616, USA
- Department of Mechanical and Aerospace Engineering, University of California, Davis, Davis, CA, 95616, USA
- Department of Civil and Environmental Engineering, University of California, Davis, Davis, CA, 95616, USA
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, CA, 95616, USA
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Phillips B, Esposito M, Verbeeck J, Boué S, Iskandar A, Vuillaume G, Leroy P, Krishnan S, Kogel U, Utan A, Schlage WK, Bera M, Veljkovic E, Hoeng J, Peitsch MC, Vanscheeuwijck P. Toxicity of aerosols of nicotine and pyruvic acid (separate and combined) in Sprague-Dawley rats in a 28-day OECD 412 inhalation study and assessment of systems toxicology. Inhal Toxicol 2015; 27:405-31. [PMID: 26295358 DOI: 10.3109/08958378.2015.1046000] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Toxicity of nebulized nicotine (Nic) and nicotine/pyruvic acid mixtures (Nic/Pyr) was characterized in a 28-day Organization for Economic Co-operation and Development 412 inhalation study with additional transcriptomic and lipidomic analyses. Sprague-Dawley rats were nose-only exposed, 6 h/day, 5 days/week to filtered air, saline, nicotine (50 µg/l), sodium pyruvate (NaPyr, 33.9 µg/l) or equimolar Nic/Pyr mixtures (18, 25 and 50 µg nicotine/l). Saline and NaPyr caused no health effects, but rats exposed to nicotine-containing aerosols had decreased body weight gains and concentration-dependent increases in liver weight. Blood neutrophil counts were increased and lymphocyte counts decreased in rats exposed to nicotine; activities of alkaline phosphatase and alanine aminotransferase were increased, and levels of cholesterol and glucose decreased. The only histopathologic finding in non-respiratory tract organs was increased liver vacuolation and glycogen content. Respiratory tract findings upon nicotine exposure (but also some phosphate-buffered saline aerosol effects) were observed only in the larynx and were limited to adaptive changes. Gene expression changes in the lung and liver were very weak. Nic and Nic/Pyr caused few significant changes (including Cyp1a1 gene upregulation). Changes were predominantly related to energy metabolism and fatty acid metabolism but did not indicate an obvious toxicity-related response. Nicotine exposure lowered plasma lipids, including cholesteryl ester (CE) and free cholesterol and, in the liver, phospholipids and sphingolipids. Nic, NaPyr and Nic/Pyr decreased hepatic triacylglycerol and CE. In the lung, Nic and Nic/Pyr increased CE levels. These data suggest that only minor biologic effects related to inhalation of Nic or Nic/Pyr aerosols were observed in this 28-day study.
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Affiliation(s)
- Blaine Phillips
- a Philip Morris International Research Laboratories Pte Ltd , Science Park II , Singapore and
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Martin SA, Oshiro WM, Evansky PA, Degn LL, Ledbetter AD, Ford J, Todd Krantz Q, LeFew WR, Beasley TE, El-Masri H, McLanahan ED, Boyes WK, Bushnell PJ. Use of novel inhalation kinetic studies to refine physiologically-based pharmacokinetic models for ethanol in non-pregnant and pregnant rats. Inhal Toxicol 2015; 26:598-619. [PMID: 25144475 DOI: 10.3109/08958378.2014.938184] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ethanol (EtOH) exposure induces a variety of concentration-dependent neurological and developmental effects in the rat. Physiologically-based pharmacokinetic (PBPK) models have been used to predict the inhalation exposure concentrations necessary to produce blood EtOH concentrations (BEC) in the range associated with these effects. Previous laboratory reports often lacked sufficient detail to adequately simulate reported exposure scenarios associated with BECs in this range, or lacked data on the time-course of EtOH in target tissues (e.g. brain, liver, eye, fetus). To address these data gaps, inhalation studies were performed at 5000, 10 000, and 21 000 ppm (6 h/d) in non-pregnant female Long-Evans (LE) rats and at 21 000 ppm (6.33 h/d) for 12 d of gestation in pregnant LE rats to evaluate our previously published PBPK models at toxicologically-relevant blood and tissue concentrations. Additionally, nose-only and whole-body plethysmography studies were conducted to refine model descriptions of respiration and uptake within the respiratory tract. The resulting time-course and plethysmography data from these in vivo studies were compared to simulations from our previously published models, after which the models were recalibrated to improve descriptions of tissue dosimetry by accounting for dose-dependencies in pharmacokinetic behavior. Simulations using the recalibrated models reproduced these data from non-pregnant, pregnant, and fetal rats to within a factor of 2 or better across datasets, resulting in a suite of model structures suitable for simulation of a broad range of EtOH exposure scenarios.
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Affiliation(s)
- Sheppard A Martin
- Neurotoxicology Branch/Toxicity Assessment Division, Office of Research and Development (ORD), US Environmental Protection Agency , Research Triangle Park, NC , USA
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Jorge-Nebert LF, Gálvez-Peralta M, Landero Figueroa J, Somarathna M, Hojyo S, Fukada T, Nebert DW. Comparing gene expression during cadmium uptake and distribution: untreated versus oral Cd-treated wild-type and ZIP14 knockout mice. Toxicol Sci 2014; 143:26-35. [PMID: 25294218 DOI: 10.1093/toxsci/kfu204] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The nonessential metal cadmium (Cd) is toxic only after entering the cell. Proteins possibly relevant to intracellular Cd accumulation include the divalent metal transporter-1 (DMT1) and all 14 zinc-like iron-like protein (ZIP) importers, 10 zinc transporter (ZnT) exporters, and metallothionein chaperones MT1 and MT2. Comparing oral Cd-treated ZIP14 knockout (KO) with wild-type (WT) mice, we predicted Cd uptake and distribution would be diminished in the KO-because ZIP14 is very highly expressed in GI tract and liver; this was indeed observed for Cd content in liver. However, the reverse was found in kidney and lung from 6 or 12 h through 10 days of Cd exposure; at these times, Cd accumulation was unexpectedly greater in KO than WT mice; mRNA levels of the 27 above-mentioned genes were thus examined in proximal small intestine (PSI) versus kidney to see if these paradoxical effects could be explained by substantial alterations in any of the other 26 genes. PSI genes highly expressed in untreated WT animals included seven ZIP and five ZnT transporters, DMT1, MT1, and MT2; kidney genes included 11 ZIP and 7 ZnT transporters, DMT1, MT1, and MT2. Over 10 days of oral Cd, a bimodal response was seen for Cd content in PSI and for various mRNAs; initially, acute effects caused by the toxic metal; subsequently, the up- or down-regulation of important genes presumably to combat the sustained adversity. These data underscore the complex interplay between the gastrointestinal tract and renal proteins that might be relevant to Cd uptake and distribution in animals exposed to oral Cd.
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Affiliation(s)
- Lucia F Jorge-Nebert
- *Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0056, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, Laboratory for Homeostatic Network, RIKEN Center for Integrative Medical Sciences, Tsurumi, Yokohama, Kanagawa 230-0045, Japan, Deutsches Rheuma-Forschungszentrum, Berlin, Osteoimmunology, 10117 Berlin, Germany and Division of Pathology, Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Shinagawa, Tokyo 142-8555, Japan
| | - Marina Gálvez-Peralta
- *Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0056, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, Laboratory for Homeostatic Network, RIKEN Center for Integrative Medical Sciences, Tsurumi, Yokohama, Kanagawa 230-0045, Japan, Deutsches Rheuma-Forschungszentrum, Berlin, Osteoimmunology, 10117 Berlin, Germany and Division of Pathology, Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Shinagawa, Tokyo 142-8555, Japan
| | - Julio Landero Figueroa
- *Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0056, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, Laboratory for Homeostatic Network, RIKEN Center for Integrative Medical Sciences, Tsurumi, Yokohama, Kanagawa 230-0045, Japan, Deutsches Rheuma-Forschungszentrum, Berlin, Osteoimmunology, 10117 Berlin, Germany and Division of Pathology, Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Shinagawa, Tokyo 142-8555, Japan
| | - Maheshika Somarathna
- *Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0056, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, Laboratory for Homeostatic Network, RIKEN Center for Integrative Medical Sciences, Tsurumi, Yokohama, Kanagawa 230-0045, Japan, Deutsches Rheuma-Forschungszentrum, Berlin, Osteoimmunology, 10117 Berlin, Germany and Division of Pathology, Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Shinagawa, Tokyo 142-8555, Japan
| | - Shintaro Hojyo
- *Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0056, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, Laboratory for Homeostatic Network, RIKEN Center for Integrative Medical Sciences, Tsurumi, Yokohama, Kanagawa 230-0045, Japan, Deutsches Rheuma-Forschungszentrum, Berlin, Osteoimmunology, 10117 Berlin, Germany and Division of Pathology, Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Shinagawa, Tokyo 142-8555, Japan *Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0056, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, Laboratory for Homeostatic Network, RIKEN Center for Integrative Medical Sciences, Tsurumi, Yokohama, Kanagawa 230-0045, Japan, Deutsches Rheuma-Forschungszentrum, Berlin, Osteoimmunology, 10117 Berlin, Germany and Division of Pathology, Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Shinagawa, Tokyo 142-8555, Japan
| | - Toshiyuki Fukada
- *Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0056, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, Laboratory for Homeostatic Network, RIKEN Center for Integrative Medical Sciences, Tsurumi, Yokohama, Kanagawa 230-0045, Japan, Deutsches Rheuma-Forschungszentrum, Berlin, Osteoimmunology, 10117 Berlin, Germany and Division of Pathology, Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Shinagawa, Tokyo 142-8555, Japan *Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0056, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, Laboratory for Homeostatic Network, RIKEN Center for Integrative Medical Sciences, Tsurumi, Yokohama, Kanagawa 230-0045, Japan, Deutsches Rheuma-Forschungszentrum, Berlin, Osteoimmunology, 10117 Berlin, Germany and Division of Pathology, Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Shinagawa, Tokyo 142-8555, Japan
| | - Daniel W Nebert
- *Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0056, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, Laboratory for Homeostatic Network, RIKEN Center for Integrative Medical Sciences, Tsurumi, Yokohama, Kanagawa 230-0045, Japan, Deutsches Rheuma-Forschungszentrum, Berlin, Osteoimmunology, 10117 Berlin, Germany and Division of Pathology, Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Shinagawa, Tokyo 142-8555, Japan
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Sidestream smoke exposure increases the susceptibility of airway epithelia to adenoviral infection. PLoS One 2012; 7:e49930. [PMID: 23166798 PMCID: PMC3499494 DOI: 10.1371/journal.pone.0049930] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 10/17/2012] [Indexed: 12/24/2022] Open
Abstract
Background Although significant epidemiological evidence indicates that cigarette smoke exposure increases the incidence and severity of viral infection, the molecular mechanisms behind the increased susceptibility of the respiratory tract to viral pathogens are unclear. Adenoviruses are non-enveloped DNA viruses and important causative agents of acute respiratory disease. The Coxsackievirus and adenovirus receptor (CAR) is the primary receptor for many adenoviruses. We hypothesized that cigarette smoke exposure increases epithelial susceptibility to adenovirus infection by increasing the abundance of apical CAR. Methodology and Findings Cultured human airway epithelial cells (CaLu-3) were used as a model to investigate the effect of sidestream cigarette smoke (SSS), mainstream cigarette smoke (MSS), or control air exposure on the susceptibility of polarized respiratory epithelia to adenoviral infection. Using a Cultex air-liquid interface exposure system, we have discovered novel differences in epithelial susceptibility between SSS and MSS exposures. SSS exposure upregulates an eight-exon isoform of CAR and increases adenoviral entry from the apical surface whilst MSS exposure is similar to control air exposure. Additionally, the level of cellular glycogen synthase kinase 3β (GSK3β) is downregulated by SSS exposure and treatment with a specific GSK3β inhibitor recapitulates the effects of SSS exposure on CAR expression and viral infection. Conclusions This is the first time that SSS exposure has been shown to directly enhance the susceptibility of a polarized epithelium to infection by a common respiratory viral pathogen. This work provides a novel understanding of the impact of SSS on the burden of respiratory viral infections and may lead to new strategies to alter viral infections. Moreover, since GSK3β inhibitors are under intense clinical investigation as therapeutics for a diverse range of diseases, studies such as these might provide insight to extend the use of clinically relevant therapeutics and increase the understanding of potential side effects.
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Elsherbiny ME, Brocks DR. The ability of polycyclic aromatic hydrocarbons to alter physiological factors underlying drug disposition. Drug Metab Rev 2011; 43:457-75. [DOI: 10.3109/03602532.2011.596204] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Coggins CRE. A further review of inhalation studies with cigarette smoke and lung cancer in experimental animals, including transgenic mice. Inhal Toxicol 2011; 22:974-83. [PMID: 20698816 DOI: 10.3109/08958378.2010.501831] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
CONTEXT The lack of an effective animal model for pulmonary carcinogenesis in smokers is a continuing problem for researchers trying to design Potentially Reduced Risk Products for those smokers who are either unwilling or unable to quit smoking. The major failing of inhalation assays with cigarette smoke in laboratory animals is that these assays produce only small percentages of animals with pulmonary tumors (e.g. adenomas, with the occasional adenocarcinoma), as opposed to the highly invasive carcinomas (e.g. small cell and squamous cell) seen in smokers. OBJECTIVE To update previous reviews on animal models, and to add different types of transgenic (Tg) mice to the review. METHODS Reviews were made of articles retrieved from PubMed and elsewhere. RESULTS The addition of Tg mice to the arsenal of tests used for the evaluation of the carcinogenic potential of cigarettes did not result in any better understanding of the inability of such testing to reflect the epidemiological evidence for lung cancer in smokers. CONCLUSION As in previous reviews on the subject, the best assay providing support for the epidemiology data is still the 5-month whole-body exposure of male A/J mice to a combination of mainstream/sidestream smoke, followed by a 4-month recovery.
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Affiliation(s)
- C R E Coggins
- Carson Watts Consulting, King, North Carolina 27021-7453, USA.
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Basyigit I, Sahin M, Sahin D, Yildiz F, Boyaci H, Sirvanci S, Ercan F. Anti-inflammatory effects of montelukast on smoke-induced lung injury in rats. Multidiscip Respir Med 2010; 5:92-8. [PMID: 22958835 PMCID: PMC3463093 DOI: 10.1186/2049-6958-5-2-92] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 01/19/2010] [Indexed: 11/25/2022] Open
Abstract
Aim To evaluate the effects of montelukast in smoke-induced lung injury. Methods 28 Wistar-Albino rats were enrolled into 4 groups with 7 rats per group. The healthy control group was exposed to fresh air while all rats in the 3 experimental groups were exposed to cigarette smoke for 20 weeks for 2 hours per day. After histopathological verification of smoke induced lung injury, montelukast (0.1 mg/kg) dissolved in Na2CO3 was given in one group (MON), Na2CO3 only was given in another group (MON control) and placebo was injected in the third group (COPD control) intraperitoneally for 21 days. At the end of this period blood samples were obtained for serum TNF-α assessment and light and electron microscopy analyses were performed on the lung tissues of sacrificed rats. Results Serum TNF-α levels in the MON group were significantly lower than in the MON control and COPD control groups (38.84 ± 4.9 pg/ml, 77.5 ± 5.8 pg/ml and 79.2 ± 6.9 pg/ml respectively, p < 0.05). Furthermore there was no statistically significant difference between the MON group and healthy controls with respect to serum TNF-α levels (38.84 ± 4.9 pg/ml vs. 29.5 ± 3.6 pg/ml, p > 0.05). Light and electron microscopic evaluation of the lungs demonstrated that the total histopathological damage score of the lung samples was significantly lower in the MON group than in MON controls and COPD controls (5.14 ± 0.5, 8.4 ± 0.6 and 8.7 ± 0.4 respectively, p < 0.05), while there was no significant difference between the MON group and healthy controls (5.1 ± 0.6 vs 2.3 ± 0.2, p > 0.05). Conclusion These findings suggest that montelukast might have a protective effect on smoke-induced lung injury in rats both from a histopathological and inflammatory point of view.
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Affiliation(s)
- Ilknur Basyigit
- Department of Pulmonary Diseases, School of Medicine, Kocaeli University, Kocaeli, Turkey.
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Olivera D, Knall C, Boggs S, Seagrave J. Cytoskeletal modulation and tyrosine phosphorylation of tight junction proteins are associated with mainstream cigarette smoke-induced permeability of airway epithelium. EXPERIMENTAL AND TOXICOLOGIC PATHOLOGY : OFFICIAL JOURNAL OF THE GESELLSCHAFT FUR TOXIKOLOGISCHE PATHOLOGIE 2010; 62:133-43. [PMID: 19376691 DOI: 10.1016/j.etp.2009.03.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Accepted: 03/13/2009] [Indexed: 11/29/2022]
Abstract
Cigarette smoke increases the permeability of the lung epithelium. Consequences of increased permeability include increased access of toxins and pathogens from the air spaces to the interstitium and even the blood stream, and leakage of fluids into the air spaces. The mechanisms for permeability alterations have not been elucidated for airway epithelia. By analogy with other types of epithelia, we hypothesized that changes in the phosphorylation status and function of tight junction (TJ) or cytoskeletal proteins might mediate the smoke-induced permeability changes. We investigated the effects of exposure to mainstream cigarette smoke (MS) on cultures of Calu-3 cells, an airway epithelial cell line. Specifically, MS exposure caused increases in phosphorylation of the myosin-binding subunit (MBS) of myosin phosphatase and myosin light chain (MLC), proteins involved in the regulation of actin polymerization. These results implicate activation of Rho kinase (ROCK), consistent with previously reported data indicating that inhibition of ROCK activation suppressed MS-induced increases in permeability. MS exposure also increased polymerized (filamentous) actin (f-actin) content and caused redistribution of the TJ proteins from the normal apical circumferential band to a more basal location. The translocation of the TJ proteins was spatially associated with local increases in both f-actin and macromolecular permeability. Finally, MS exposure increased tyrosine phosphorylation of occludin but not ZO-1 and decreased association between the two TJ proteins. These results indicate that MS exposure causes alterations in cytoskeletal and TJ structure and function, resulting in increased macromolecular permeability that may contribute to the adverse health effects of MS.
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Affiliation(s)
- Dorian Olivera
- Division of Pathophysiology, Lovelace Respiratory Research Institute, 2425 Ridgecrest SE, Albuquerque, NM 87108, USA
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Karrasch S, Eder G, Bolle I, Tsuda A, Schulz H. Breath-by-breath measurement of particle deposition in the lung of spontaneously breathing rats. J Appl Physiol (1985) 2009; 107:1293-9. [PMID: 19644034 PMCID: PMC2763828 DOI: 10.1152/japplphysiol.00096.2009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Accepted: 07/27/2009] [Indexed: 11/22/2022] Open
Abstract
A number of deposition models for humans, as well as experimental animals, have been described. However, no breath-by-breath deposition measurement in rats has been reported to date. The objective of this study is to determine lung deposition of micrometer-sized particles as a function of breathing parameters in the adult rat lung. A new aerosol photometry system was designed to measure deposition of nonhygroscopic, 2-mum sebacate particles in anesthetized, intubated, and spontaneously breathing 90-day-old Wistar-Kyoto rats placed in a size-adjusted body plethysmograph box. Instrumental dead space of the system was minimized down to 310 microl (i.e., approximately 20% of respiratory dead space). The system allows continuous monitoring of particle concentration in the respired volume. Breathing parameters, such as respiratory rate (f), tidal volume (Vt), as well as inspiration/expiration times, were also monitored at different levels of anesthesia. The results showed that Vt typically varied between 1.5 and 4.0 ml for regular breathing and between 4.0 and 10.0 ml for single-sigh breaths; f ranged from 40 to 200 breaths/min. Corresponding deposition values varied between 5 and 50%, depending on breath-by-breath breathing patterns. The best fit of deposition (D) was achieved by a bilinear function of Vt and f and found to be D = 11.0 - 0.09.f + 3.75.Vt. We conclude that our approach provides more realistic conditions for the measurement of deposition than conventional models using ventilated animals and allows us to analyze the correlation between breath-specific deposition and spontaneous breathing patterns.
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Affiliation(s)
- S. Karrasch
- Institute of Lung Biology and Disease, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; and
| | - G. Eder
- Institute of Lung Biology and Disease, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; and
| | - I. Bolle
- Institute of Lung Biology and Disease, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; and
| | - A. Tsuda
- Molecular and Integrative Physiological Sciences, Harvard School of Public Health, Boston, Massachusetts
| | - H. Schulz
- Institute of Lung Biology and Disease, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; and
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He L, Wang B, Hay EB, Nebert DW. Discovery of ZIP transporters that participate in cadmium damage to testis and kidney. Toxicol Appl Pharmacol 2009; 238:250-7. [PMID: 19265717 DOI: 10.1016/j.taap.2009.02.017] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Revised: 02/10/2009] [Accepted: 02/13/2009] [Indexed: 12/16/2022]
Abstract
It has been known for decades that cadmium (Cd) must enter the cell to cause damage, but there was no mechanism to explain genetic differences in response to Cd toxicity until 2005. Starting with the mouse Cdm locus associated with differences in Cd-induced testicular necrosis between inbred strains, a 24.6-centiMorgan region on chromosome 3 was reduced ultimately to 880 kb; in this segment is the Slc39a8 gene encoding the ZIP8 Zn(2+)/HCO(3)(-) symporter. In endothelial cells of the testis vasculature, Cd-sensitive mice exhibit high ZIP8 expression, Cd-resistant mice exhibit very low expression. A 168.7-kb bacterial artificial chromosome (BAC) from a 129S6 (Cd-sensitive) BAC library containing the Slc39a8 gene was inserted into the Cd-resistant C57BL/6J genome: Cd treatment produced testicular necrosis in BAC-transgenic BTZIP8-3 mice but not in non-transgenic littermates, thereby proving that the Slc39a8 gene is indeed the Cdm locus. Cd-induced renal failure also occurred in these BTZIP8-3 mice. Immunohistochemistry showed highly expressed ZIP8 protein in the renal proximal tubular epithelial apical surface, suggesting that ZIP8 participates in Cd-induced renal failure. Slc39a14, most closely evolutionarily related to Slc39a8, encodes differentially-spliced products ZIP14A and ZIP14B that display properties similar to ZIP8. ZIP8 in alveolar cells brings environmental Cd into the organism and ZIP14 in intestinal enterocytes carries Cd into the organism and into the hepatocyte. We believe these two transporters function endogenously as Zn(2+)/HCO(3)(-) symporters important in combating inflammation and carrying out other physiological functions; Cd is able to displace the endogenous cation, enter the cell, and produce tissue damage and disease.
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Affiliation(s)
- Lei He
- Department of Environmental Health, University of Cincinnati Medical Center, Cincinnati, OH 45267-0056, USA
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Chen BT, Benz JV, Finch GL, Mauderly JL, Sabourin PJ, Yeh HC, Snipes MB. Effect of Exposure Mode on Amounts of Radiolabeled Cigarette Particles in Lungs and Gastrointestinal Tracts of F344 Rats. Inhal Toxicol 2008. [DOI: 10.3109/08958379509002569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Ghelfi E, Rhoden CR, Wellenius GA, Lawrence J, Gonzalez-Flecha B. Cardiac Oxidative Stress and Electrophysiological Changes in Rats Exposed to Concentrated Ambient Particles are Mediated by TRP-Dependent Pulmonary Reflexes. Toxicol Sci 2008; 102:328-36. [DOI: 10.1093/toxsci/kfn005] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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15
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Olivera DS, Boggs SE, Beenhouwer C, Aden J, Knall C. Cellular mechanisms of mainstream cigarette smoke-induced lung epithelial tight junction permeability changes in vitro. Inhal Toxicol 2007; 19:13-22. [PMID: 17127639 DOI: 10.1080/08958370600985768] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Mainstream cigarette smoke increases the permeability of human airways; however, the mechanism for this increased permeability is poorly defined. Tight junctions between adjacent epithelial cells constitute the physiological barrier to fluid and macromolecules in epithelium. These structures are highly regulated by phosphorylation and their association with the cytoskeleton. The goal of these studies was to identify the signal transduction pathways that regulate smoke-induced permeability. Using a physiologically relevant air-liquid interface exposure system, electrically tight monolayers of the human bronchial epithelial cell-line Calu-3 were exposed to fresh, whole mainstream cigarette smoke. This exposure results in a regulated, dose-dependent loss of epithelial barrier function in the lung epithelial monolayers. With cigarette smoke exposure, transepithelial electrical resistance (TER) is decreased and albumin flux is increased, indicating a loss in barrier function to ions and macromolecules, respectively; however, both largely recover in 30 min. Smoke-induced losses of macromolecular barrier function are the result of multicellular junctional reorganization, resulting in increased leak volume rather than leak frequency. Inhibiting Rho kinase (ROCK) significantly reduces the smoke-induced permeability to both ions and macromolecules, while inhibiting protein tyrosine kinases (PTK) only reduces smoke-induced macromolecular permeability. Interestingly, inhibiting myosin light chain kinase (MLCK) exacerbates smoke-induced permeability, indicating that MLCK and ROCK have opposing regulatory roles. Our results demonstrate that the smoke-induced loss of epithelial barrier function in human bronchial epithelium is a regulated process rather than a cytotoxic response. Additionally, our results indicate that activation of PTK and ROCK and inactivation of MLCK contribute to the increased airway permeability caused by mainstream cigarette smoke.
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Affiliation(s)
- Dorian S Olivera
- Program in Toxicology, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
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16
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Işik ACU, Yardimci S, Guven C, Avunduk MC, Civelek S. Morphologic alteration induced by short-term smoke exposure in rats. ORL J Otorhinolaryngol Relat Spec 2006; 69:13-7. [PMID: 17085947 DOI: 10.1159/000096711] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Accepted: 01/20/2005] [Indexed: 11/19/2022]
Abstract
BACKGROUND It is a well-established fact that cigarette smoking causes degenerative, inflammatory, and respiratory diseases in humans. Because many factors such as air pollution and harsh working conditions can easily be eliminated in animal studies, we conducted this study to identify the effect of tobacco on rat trachea. METHODS 24 male Wistar rats were divided randomly into an experimental and a control group. The experimental group of rats was exposed to cigarette smoke for 2 h each day over a duration of 60 consecutive days and the control group was treated in an identical fashion yet exposed only to room air. A morphometric study was performed on tracheal specimens taken from 22 rats (10 smoke-exposed rats and 12 control rats). RESULTS Our results show that many of the morphological changes of the tracheal epithelium were found in the experimental group and significant quantitative differences were observed between the two groups. Loss of cilia, basal cell hyperplasia, goblet cell hyperplasia and an increased number of subepithelial inflammatory cells were observed by light microscopic examination of the trachea of experimental rats. We found very high levels of plasma thiocyanate after exposure to smoke in the experimental group, but no increase in the control group. CONCLUSIONS The oxidants contained tobacco which could play an important role in the development of these structural and functional abnormalities in the trachea after smoke exposure. In addition, smoking can recruit inflammatory cells to the trachea.
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Affiliation(s)
- A Cemal Umit Işik
- Department of Otolaryngology, School of Medicine, Karadeniz Technical University, Trabzon, Turkey.
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Wichers LB, Ledbetter AD, McGee JK, Kellogg RB, Rowan WH, Nolan JP, Costa DL, Watkinson WP. A method for exposing rodents to resuspended particles using whole-body plethysmography. Part Fibre Toxicol 2006; 3:12. [PMID: 16911796 PMCID: PMC1570473 DOI: 10.1186/1743-8977-3-12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Accepted: 08/15/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Epidemiological studies have reported increased risks of cardiopulmonary-related hospitalization and death in association with exposure to elevated levels of particulate matter (PM) across a wide range of urban areas. In response to these findings, researchers have conducted animal inhalation exposures aimed at reproducing the observed toxicologic effects. However, it is technically difficult to quantitate the actual amount of PM delivered to the lung in such studies, and dose is frequently estimated using default respiration parameters. Consequently, the interpretation of PM-induced effects in rodents exposed via whole-body inhalation is often compromised by the inability to determine deposited dose. To address this problem, we have developed an exposure system that merges the generation of dry, aerosolized particles with whole-body plethysmography (WBP), thus permitting inhalation exposures in the unrestrained rat while simultaneously obtaining data on pulmonary function. RESULTS This system was validated using an oil combustion-derived particle (HP12) at three nominal concentrations (3, 12, and 13 mg/m3) for four consecutive exposure days (6 hr/day); a single 6-hour exposure to 13 mg/m3 of HP12 was also conducted. These results demonstrated that the system was both reliable and consistent over these exposure protocols, achieving average concentrations that were within 10% of the targeted concentration. In-line filters located on the exhaust outlets of individual WBP chambers showed relative agreement in HP12 mass for each day and were not statistically different when compared to one another (p = 0.16). Temperatures and relative humidities were also similar between chambers during PM and air exposures. Finally, detailed composition analyses of both HP12 filter and bulk samples showed that grinding and aerosolization did not change particle chemistry. CONCLUSION The results of this study demonstrate that it is possible to expose rodents to resuspended, dry PM via whole-body inhalation while these animals are maintained in WBP chambers. This new methodology should significantly improve the ability to assess dosimetry under minimally stressful exposure conditions.
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Affiliation(s)
- Lindsay B Wichers
- Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina, Chapel Hill, North Carolina 27599, USA
- Environmental Media Assessment Group, National Center for Environmental Assessment, Office of Research and Development, Research Triangle Park, North Carolina 27711, USA
| | - Allen D Ledbetter
- Pulmonary Toxicology Branch, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - John K McGee
- Pulmonary Toxicology Branch, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - Robert B Kellogg
- Alion Science and Technology Corporation, Research Triangle Park, North Carolina 27711, USA
| | - William H Rowan
- Pulmonary Toxicology Branch, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - Julianne P Nolan
- Pulmonary Toxicology Branch, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - Daniel L Costa
- Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - William P Watkinson
- Pulmonary Toxicology Branch, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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18
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Wichers LB, Rowan WH, Nolan JP, Ledbetter AD, McGee JK, Costa DL, Watkinson WP. Particle deposition in spontaneously hypertensive rats exposed via whole-body inhalation: measured and estimated dose. Toxicol Sci 2006; 93:400-10. [PMID: 16840562 DOI: 10.1093/toxsci/kfl059] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A plethora of epidemiological studies have shown that exposure to elevated levels of ambient particulate matter (PM) can lead to adverse health outcomes, including cardiopulmonary-related mortality. Subsequent animal toxicological studies have attempted to mimic these cardiovascular and respiratory responses, in order to better understand underlying mechanisms. However, it is difficult to quantitate the amount of PM deposited in rodent lungs following inhalation exposure, thus making fundamental dose-to-effect assessment and linkages to human responses problematic. To address this need, spontaneously hypertensive rats were exposed to an oil combustion-derived PM (HP12) via inhalation while being maintained in whole-body plethysmograph chambers. Rats were exposed 6 h/day to 13 mg/m(3) of HP12 for 1 or 4 days. Immediately following the last exposure, rats were sacrificed and their tracheas and lung lobes harvested and separated for neutron activation analysis. Total lower respiratory tract deposition ranged from 20-60 microg to 89-139 microg for 1- and 4-day exposures, respectively. Deposition data were compared to default and rat-specific estimates provided by the Multiple Path Particle Deposition (MPPD) model, yielding model predictions that were < 33% of the measured dose. This study suggests that HP12 exposure decreased particle clearance, as the mass of HP12 in the lungs following a 4-day protocol was nearly four times that observed after a 1-day exposure. This work should improve the ability of risk assessors to extrapolate rat-to-human exposure concentrations on the basis of lung burdens and, thus, better relate inhaled doses and resultant toxicological effects.
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Affiliation(s)
- Lindsay B Wichers
- Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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19
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Wang XL, Wang J. Smoking-gene interaction and disease development: relevance to pancreatic cancer and atherosclerosis. World J Surg 2005; 29:344-53. [PMID: 15696395 DOI: 10.1007/s00268-004-7819-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
There is little doubt that cigarette smoking remains a major environmental health risk that humans are facing in the twenty-first century. Cigarette smokers are more likely to develop many forms of diseases than nonsmokers, including cancers and vascular diseases. With the availability of the human genome sequence, we become more aware of the genetic contributions to these common diseases, especially the interactive relations between environmental factors (e.g., smoking) and genes on disease susceptibility, development, and prognosis. Although smoking is responsible for up to 30% of pancreatic cancers and about 10% of cases are ascribed to genetic reasons, some genetic variants do not predispose carriers to disease development unless they are exposed to a specific adverse environment such as smoking. This smoke-gene interaction could potentially be responsible for most of the cases. Certain polymorphisms in genes such as CYP1A1 have been shown particularly sensitive to smoking-induced pathogenesis, including pancreatic cancer and atherosclerosis. We found that individuals with CYP1A1 CC genotype had a more than three fold increase in risk for severe coronary atherosclerosis when they smoked. Patients with endothelial nitric oxide synthase (eNOS) intron 4 27 repeat homozygotes were more likely to develop severe coronary stenosis when they smoked. On the other hand, DNA variants at the eNOS gene also dictate how smoking affects the expression of eNOS. We showed that GSTM1 deficiency was not involved in smoking-induced vascular diseases, but p53 polymorphisms tended to modify the disease severity in smokers. We are still at an early stage of defining the pairs and mechanisms of smoke-gene interaction, and this etiologic mechanism may hold great potential for risk assessment, treatment strategy, and prognostic predictions.
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Affiliation(s)
- Xing Li Wang
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, MS NAB 2010, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA.
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20
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Abstract
Cigarette smoking as an addictive habit has accompanied human beings for more than 4 centuries. It is also one of the most potent and prevalent environmental health risks human beings are exposed to, and it is responsible for more than 1000 deaths each day in the United States. With recent research progress, it becomes clear that cigarette smoking can cause almost all major diseases prevalent today, such as cancer or heart disease. These detrimental effects are not only present in active smokers who choose the risk, but also to innocent bystanders, as passive smokers, who are exposed to cigarettes not-by-choice. While the cigarette-induced harm to human health is indiscriminate and severe, the degree of damage also varies from individual to individual. This intersubject variability in cigarette-induced pathologies is partly mediated by genetic variants of genes that may participate in detoxification process, eg, cytochrome P450 (CYP), cellular susceptibility to toxins, such as p53, or disease development. Through population studies, we have learned that certain CYP1A1 variants, such as Mspl polymorphism, may render the carriers more susceptible to cigarette-induced lung cancer or severe coronary atherosclerosis. The endothelial nitric oxide synthase intron 4 rare allele homozygotes are more likely to have myocardial infarction if they also smoke. In vitro experimental approach has further demonstrated that cigarettes may specifically regulate these genes in genotype-dependent fashion. While we still know little about genetic basis and molecular pathways for cigarette-induced pathological changes, understanding these mechanisms will be of great value in designing strategies to further reduce smoking in targeted populations, and to implement more effective measures in prevention and treatment of cigarette-induced diseases.
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Affiliation(s)
- Xing Li Wang
- Vascular Genetics Laboratory, Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, TX 78227, USA.
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Avunduk AM, Yardimci S, Avunduk MC, Kurnaz L. Cadmium and iron accumulation in rat lens after cigarette smoke exposure and the effect of vitamin E (alpha-tocopherol) treatment. Curr Eye Res 1999; 18:403-7. [PMID: 10435826 DOI: 10.1076/ceyr.18.6.403.5268] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE Cadmium accumulation in the lens has been implicated in cataractogenesis of chronic smokers. This study was planned to evaluate whether or not in vivo cigarette smoke exposure causes cadmium accumulation in rat lens, and possible protective effect and mechanism of alpha-tocopherol (vitamin E) treatment on cataractogenesis. METHODS 28 male Wistar rats were randomly divided into four equal groups. Group 3 and 4 rats were exposed to cigarette smoke over ninety consecutive days, and Group 1 and 2 rats were treated in a similar fashion but exposed only to room air. Additionally, vitamin E was given to Group 2 and 4 rats. RESULTS Significantly higher iron levels were observed in the lenses of Group 3 rats compared to other groups. With respect to cadmium, Group 3 and 4 rats had significantly higher levels compared to Group 1 and 2 rats. Although vitamin E treatment prevented iron accumulation in Group 4 rats, it had no effect on cadmium concentrations. Distinct histopathological changes observed in Group 3 rats were not present in Group 4 rats. CONCLUSION Our study demonstrates that in vivo cigarette smoke exposure causes accumulation of cadmium in rat lens and IM vitamin E treatment does not affect this accumulation. The protective effect of vitamin E treatment on smoke exposed rat lens seems to be mediated by blockage of iron accumulation in the lens.
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Affiliation(s)
- A M Avunduk
- Karadeniz Technical University, School of Medicine, Department of Ophthalmology, Trabzon, Turkey.
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Nilsson K, Henriksson R, Cai YQ, Hellström S, Hörnqvist Bylunds S, Bjermer L. Effects of tobacco-smoke on radiation-induced pneumonitis in rats. Int J Radiat Biol 1993; 62:719-27. [PMID: 1362765 DOI: 10.1080/09553009214552671] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
To investigate the effect of exposure to tobacco smoke (TS) on the development of irradiation-induced pneumonitis in rats, five groups of animals were investigated including controls (C), tobacco smoke exposed (S), irradiated (RNS) and irradiated and tobacco smoke exposed (RS). An additional group (RS/NS) was exposed to tobacco before irradiation but not afterwards. Rats were exposed to diluted mainstream cigarette smoke at a concentration of about 0.4 mg/l in a nose-only exposure system for 1/day, 5 days/week for 10 weeks. Exposure to TS started 3 weeks before irradiation in which the basal one-third of both lungs was exposed to a single dose of 28 Gy. In previous studies this dose had been shown to cause significant pneumonitis. All the animals were killed at 7 weeks after irradiation. Examination of the morphology of lung sections showed less pulmonary inflammation in the RS group than in the RNS group. This was also reflected in the results of bronchoalveolar lavage (BAL) which showed a decline in cell recovery and a marked decrease in the numbers of mast cells and neutrophils in the RS rats compared with the RNS animals. The concentration of hyaluronan in lavage fluid was increased in the RNS and RS/NS group while no increase was found in the RS group. A marked increase in BAL protein was also seen in the RNS and RS/NS groups as compared with the RS group but all were significantly higher than in unirradiated controls. This indicates that smoking suppresses the radiation-induced inflammation but to a lesser degree affects the radiation-induced increase in membrane permeability as reflected by increased protein levels in BAL. Moreover, the marked effects on the numbers of mast cells and neutrophils in the RS group may indicate that these cells play an important role in the mechanism by which tobacco smoke modulates the effects of irradiation. When exposure to tobacco smoke was terminated immediately after irradiation (RS/NS), the inflammatory response was unaffected.
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Affiliation(s)
- K Nilsson
- Department of Lung medicine, University Hospital, Umeå, Sweden
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23
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CHEN B, BECHTOLD W, MAUDERLY J. Description and Evaluation of a Cigarette Smoke Generation System for Inhalation Studies. ACTA ACUST UNITED AC 1992. [DOI: 10.1089/jam.1992.5.19] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Cheng YS, Hansen GK, Su YF, Yeh HC, Morgan KT. Deposition of ultrafine aerosols in rat nasal molds. Toxicol Appl Pharmacol 1990; 106:222-33. [PMID: 2256113 DOI: 10.1016/0041-008x(90)90242-m] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To evaluate the health effects of air pollutants on the respiratory tract, it is critical to determine the regional deposition of inhaled aerosols. Information on deposition of larger particles (greater than 0.2 microns) in the nasal passages of laboratory animals is available; the deposition fraction increases with increasing particle size. However, little deposition information is available for ultrafine particles of less than 0.2 microns. Three clear, plastic molds (models) of the nasal passages of F344/N rats, prepared from metal replica casts were used in these studies. Total deposition of ultrafine aerosols in the casts was determined by using a unidirectional flow system. The pressure drops measured in the casts were a function of flow rate to the power of 1.4-1.6, indicating that flow through the nasal passages has nonlaminar components. Deposition data were obtained by using monodisperse sodium chloride aerosols with particle sizes ranging from 0.2 to 0.005 microns, at inspiratory and expiratory flow rates of 200 to 600 ml/min. Similar deposition data were obtained for two of the casts studied. Deposition efficiency was greatest for the smallest particles, and decreased with increasing particle size and flow rate. At an inspiratory flow rate of 400 ml/min, which is comparable to the mean respiratory flow of an adult male F344 rat with a respiratory minute volume of 200 ml, deposition efficiencies reached 40 and 70% for 0.01- and 0.005-microns particles, respectively. These studies demonstrated that turbulent diffusional deposition was the dominant mechanism for uptake of ultrafine particles by the nasal passages.
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Affiliation(s)
- Y S Cheng
- Inhalation Toxicology Research Institute, Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico 87185
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