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Hatch GE, Crissman K, Schmid J, Richards JE, Ward WO, Schladweiler MC, Ledbetter AD, Kodavanti UP. Strain differences in antioxidants in rat models of cardiovascular disease exposed to ozone. Inhal Toxicol 2016; 27 Suppl 1:54-62. [PMID: 26667331 DOI: 10.3109/08958378.2014.954170] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We examined the hypothesis that antioxidant substances and enzymes in lung, heart and in bronchoalveolar lavage fluid (BALF) are altered in response to O3 in cardiovascular disease and/or metabolic syndrome (CVD)-prone rat models. CVD strains [spontaneously hypertensive (SH), SH stroke-prone (SHSP), SHHF/Mcc heart failure obese (SHHF), insulin-resistant JCR:LA-cp obese (JCR) and Fawn-Hooded hypertensive (FHH)] were compared with normal strains [Wistar, Sprague-Dawley (SD) and Wistar Kyoto (WKY)]. Total glutathione (GSH + GSSG or GSx), reduced ascorbate (AH2), uric acid (UA) and antioxidant enzymes were determined in lung, heart and BALF immediately (0 h) or 20-h post 4-h nose-only exposure to 0.0, 0.25, 0.5 and 1.0 ppm O3. Basal- and O3-induced antioxidant substances in tissues varied widely among strains. Wistar rats had a robust O3-induced increase in GSx and AH2 in the lung. Two CVD strains (JCR and SHHF) had high basal levels of AH2 and GSx in BALF as well as high basal lung UA. Across all strains, high BALF GSx was only observed when high BALF AH2 was present. CVD rats tended to respond less to O3 than normal. High-basal BALF AH2 levels were associated with decreased O3 toxicity. In summary, large differences were observed between both normal and CVD rat strains in low-molecular weight antioxidant concentrations in lung, BALF and heart tissue. Wistar (normal) and JCR and SHHF (CVD) rats appeared to stand out as peculiar in terms of basal- or O3-induced changes. Results elucidate interactions among antioxidants and air pollutants that could enhance understanding of cardiopulmonary disease.
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Affiliation(s)
- Gary E Hatch
- a Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA and
| | - Kay Crissman
- a Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA and
| | - Judy Schmid
- b Research Cores Unit , National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA
| | - Judy E Richards
- a Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA and
| | - William O Ward
- b Research Cores Unit , National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA
| | - Mette C Schladweiler
- a Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA and
| | - Allen D Ledbetter
- a Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA and
| | - Urmila P Kodavanti
- a Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA and
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Vinikoor-Imler LC, Owens EO, Nichols JL, Ross M, Brown JS, Sacks JD. Evaluating potential response-modifying factors for associations between ozone and health outcomes: a weight-of-evidence approach. Environ Health Perspect 2014; 122:1166-76. [PMID: 24927060 PMCID: PMC4216162 DOI: 10.1289/ehp.1307541] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 06/11/2014] [Indexed: 05/04/2023]
Abstract
BACKGROUND Epidemiologic and experimental studies have reported a variety of health effects in response to ozone (O3) exposure, and some have indicated that certain populations may be at increased or decreased risk of O3-related health effects. OBJECTIVES We sought to identify potential response-modifying factors to determine whether specific groups of the population or life stages are at increased or decreased risk of O3-related health effects using a weight-of-evidence approach. METHODS Epidemiologic, experimental, and exposure science studies of potential factors that may modify the relationship between O3 and health effects were identified in U.S. Environmental Protection Agency's 2013 Integrated Science Assessment for Ozone and Related Photochemical Oxidants. Scientific evidence from studies that examined factors that may influence risk were integrated across disciplines to evaluate consistency, coherence, and biological plausibility of effects. The factors identified were then classified using a weight-of-evidence approach to conclude whether a specific factor modified the response of a population or life stage, resulting in an increased or decreased risk of O3-related health effects. DISCUSSION We found "adequate" evidence that populations with certain genotypes, preexisting asthma, or reduced intake of certain nutrients, as well as different life stages or outdoor workers, are at increased risk of O3-related health effects. In addition, we identified other factors (i.e., sex, socioeconomic status, and obesity) for which there was "suggestive" evidence that they may increase the risk of O3-related health effects. CONCLUSIONS Using a weight-of-evidence approach, we identified a diverse group of factors that should be considered when characterizing the overall risk of health effects associated with exposures to ambient O3.
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Affiliation(s)
- Lisa C Vinikoor-Imler
- National Center for Environmental Assessment (NCEA), U.S. Environmental Protection Agency (EPA), Research Triangle Park, North Carolina, USA
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Zhao J, Xie Y, Qian X, Jiang R, Song W. Acute effects of fine particles on cardiovascular system: Differences between the spontaneously hypertensive rats and wistar kyoto rats. Toxicol Lett 2010; 193:50-60. [DOI: 10.1016/j.toxlet.2009.12.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Revised: 12/01/2009] [Accepted: 12/06/2009] [Indexed: 11/25/2022]
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Behndig AF, Blomberg A, Helleday R, Duggan ST, Kelly FJ, Mudway IS. Antioxidant responses to acute ozone challenge in the healthy human airway. Inhal Toxicol 2009; 21:933-42. [PMID: 19459773 DOI: 10.1080/08958370802603789] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The aim of the study was to characterize ozone-induced antioxidant responses in the human airway, including the resident leukocyte population, bronchial mucosa, and respiratory-tract lining fluids. Fifteen healthy subjects were exposed to 0.2 ppm ozone for 2 h, with bronchial wash, bronchoalveolar lavage, and biopsy sampling performed 6 h postexposure. Nasal lavage was also performed at multiple time points pre- and postexposure to evaluate responses during the actual exposure period. During the ozone challenge significant losses of nasal lining fluid urate and vitamin C were observed, which resolved 6 h postexposure. At this time point, increased numbers of neutrophils and enhanced concentrations of total glutathione, vitamin C, and urate were seen in bronchial airway lavages. In bronchoalveolar lavage, increased concentrations of total glutathione, vitamin C, urate, alpha-tocopherol, and extracellular superoxide dismutase occurred 6 h post ozone. In alveolar leukocytes significant losses of glutathione were observed, whereas ascorbate concentrations in endobronchial mucosal biopsies were elevated after ozone at this time. These data demonstrate that ozone elicits a broad spectrum of airway antioxidant responses, with initial losses of vitamin C and urate followed by a phase of augmentation of low-molecular-weight antioxidant concentrations at the air-lung interface. The temporal association between the increased RTLF glutathione following ozone and the loss of this thiol from macrophages implies a mobilization to the lung surface, despite the absence of a quantitative association. We propose this constitutes an acute protective adaptation to ozone.
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Affiliation(s)
- Annelie F Behndig
- Department of Respiratory Medicine and Allergy, University Hospital, Umeå, Sweden.
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Wanderer AA. Corticosteroid resistance in pulmonary neutrophilic inflammatory disorders and rationale for adjunct IL-1beta targeted therapy. Am J Respir Cell Mol Biol 2009; 41:246-7. [PMID: 19620408 DOI: 10.1165/ajrcmb.41.2.246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Behndig AF, Blomberg A, Helleday R, Kelly FJ, Mudway IS. Augmentation of Respiratory Tract Lining Fluid Ascorbate Concentrations Through Supplementation with Vitamin C. Inhal Toxicol 2009; 21:250-8. [DOI: 10.1080/08958370802474736] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Markart P, Luboeinski T, Korfei M, Schmidt R, Wygrecka M, Mahavadi P, Mayer K, Wilhelm J, Seeger W, Guenther A, Ruppert C. Alveolar oxidative stress is associated with elevated levels of nonenzymatic low-molecular-weight antioxidants in patients with different forms of chronic fibrosing interstitial lung diseases. Antioxid Redox Signal 2009; 11:227-40. [PMID: 18783310 DOI: 10.1089/ars.2008.2105] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Increasing evidence indicates that disequilibrium of the alveolar oxidant-antioxidant balance may play a role in the pathogenesis of chronic fibrosing lung diseases. Excessive production of oxidants and a differential regulation of antioxidant enzymes have been described under these conditions. We characterized for the first time numerous nonenzymatic low-molecular-weight antioxidants in bronchoalveolar lavage fluids from patients with different forms of lung fibrosis initiated either by injury to the alveolar epithelium (idiopathic pulmonary fibrosis, IPF) or by inflammation (chronic sarcoidosis/hypersensitivity pneumonitis). Footprints of oxidative stress accompanied by an increase in the majority of antioxidants assessed were observed in all patient groups: elevated levels of uric acid, ascorbic acid, retinol, and alpha-tocopherol were noted, whereas glutathione levels were unchanged. The expression of Nrf2, an important redox-sensitive transcriptional regulator of antioxidants, was increased in IPF lungs. Our findings were corroborated in the bleomycin model of lung fibrosis where--aside from uric acid--nonenzymatic antioxidants were elevated during the fibrotic phase. In conclusion, alveolar levels of nonenzymatic antioxidants are elevated in fibrosing lung diseases, but are incapable of restoring oxidative balance. This increase may be part of an adaptive response to oxidative stress. However, a leakage from the blood may also contribute to our findings.
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Affiliation(s)
- Philipp Markart
- Department of Internal Medicine, Faculty of Medicine, University of Giessen Lung Center, Giessen, Germany
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Deaton CM, Marlin DJ, Smith NC, Roberts CA, Harris PA, Schroter RC, Kelly FJ. Antioxidant and inflammatory responses of healthy horses and horses affected by recurrent airway obstruction to inhaled ozone. Equine Vet J 2005; 37:243-9. [PMID: 15892234 DOI: 10.2746/0425164054530605] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY Inhaled ozone can induce oxidative injury and airway inflammation. Horses affected by recurrent airway obstruction (RAO) have a decreased pulmonary antioxidant capacity, which may render them more susceptible to oxidative challenge. It is currently unknown whether RAO-affected horses are more susceptible to oxidative stress than those unaffected by RAO. OBJECTIVES To determine whether ozone exposure induces greater oxidative stress and airway inflammation in RAO-affected horses in remission than in healthy horses. METHODS Seven healthy control horses and 7 RAO-affected horses were exposed to 0.8 ppm ozone for 2 h at rest. RESULTS At baseline, bronchoalveolar lavage fluid (BALF) ascorbic acid concentrations were lower in RAO-affected horses than healthy controls. Ozone appeared to preferentially oxidise glutathione rather than ascorbic acid 6 h after exposure. Individual healthy and RAO-affected horses demonstrated oxidation of BALF glutathione after ozone exposure. Overall, RAO-affected horses did not demonstrate increased oxidative stress following ozone exposure, compared with healthy horses. Ozone did not induce significant airway inflammation in either group. CONCLUSIONS RAO-affected horses in remission are not more sensitive to ozone despite a decreased pulmonary antioxidant capacity. Sensitivity to ozone appears to be independent of initial pulmonary antioxidant status. POTENTIAL RELEVANCE Horses with high susceptibility to oxidative stress may benefit from antioxidant supplementation.
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Affiliation(s)
- C M Deaton
- Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, UK
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Cisneros FJ, Jayo M, Niedziela L. An Uncaria tomentosa (cat's claw) extract protects mice against ozone-induced lung inflammation. J Ethnopharmacol 2005; 96:355-364. [PMID: 15619552 DOI: 10.1016/j.jep.2004.06.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2003] [Revised: 06/14/2004] [Accepted: 06/16/2004] [Indexed: 05/24/2023]
Abstract
Ozone (O(3)) inhalation has been associated with respiratory tract inflammation and lung functional alterations. To characterize the O(3)-induced lung inflammation in mice, the effective dose and exposure time were determined. Total protein levels of bronchoalveolar lavage fluid (BALF), cytological smears, and lung histopathology and morphometry were used to assess and measure the degree of pulmonary inflammation in the mouse model. Ozone inhalation caused acute pneumonitis that was characterized by a high number of infiltrating neutrophils (PMNs) immediately after exposure and increased levels of protein in BALF in mice killed 8h after O(3) exposure. The anti-inflammatory properties of Uncaria tomentosa (UT) have been documented previously. To evaluate the anti-inflammatory effects of UT, male mice were given an UT extract for 8 days, exposed to O(3), and killed 0 or 8 h after O(3) exposure. When compared to untreated controls, UT-treated mice had significantly (p < 0.05) lower levels of protein in BALF, lower degree of epithelial necrosis, higher number of intact epithelial cell nuclei in bronchial wall, and decreased number of PMNs in the bronchiolar lumen. Therefore, UT extract appeared to prevent O(3)-induced respiratory inflammation in male mice.
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Affiliation(s)
- Francisco J Cisneros
- Department of Biology, North Carolina A & T State University, 1601 E Market St., Greensboro, NC 27411, USA.
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Schmidt R, Schäfer C, Luboeinski T, Löckinger A, Hermle G, Grimminger F, Seeger W, Ghofrani A, Schütte H, Günther A. Increase in alveolar antioxidant levels in hyperoxic and anoxic ventilated rabbit lungs during ischemia. Free Radic Biol Med 2004; 36:78-89. [PMID: 14732292 DOI: 10.1016/j.freeradbiomed.2003.10.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2003] [Revised: 10/16/2003] [Accepted: 10/27/2003] [Indexed: 10/26/2022]
Abstract
Increases in free radicals are believed to play a central role in the development of pulmonary ischemia/reperfusion (I-R) injury, leading to microvascular leakage and deterioration of pulmonary surfactant. Continued ventilation during ischemia offers significant protection against I-R injury, but the impact of alveolar oxygen supply both on lung injury and on radical generation is still unclear. We investigated the influence of hyperoxic (95% O2) and anoxic (0% O2) ventilation during ischemia on alveolar antioxidant status and surfactant properties in isolated rabbit lungs. Normoxic and hyperoxic ventilated, buffer-perfused lungs (n = 5 or 6) and native lungs (n = 6) served as controls. As compared with controls, biophysical and biochemical surfactant properties were not altered in anoxic as well as hyperoxic ventilated ischemic (2, 3, and 4 h) lungs. Assessment of several antioxidants (reduced glutathione (GSH), alpha-tocopherol (vitamin E), retinol (vitamin A), ascorbic acid (vitamin C), uric acid, and plasmalogens (1-O-alkenyl-2-acyl-phospholipids)) in bronchoalveolar lavage fluid (BALF) revealed a significant increase in antioxidant compounds under anoxic and hyperoxic ventilation, with maximum levels occuring after 3 h of ischemia. For example, GSH increased to 5.1 +/- 0.8 microM (mean +/- SE, p <.001) after 3 h of anoxic ventilated ischemia and to 2.7 +/- 0.2 microM (p <.01) after hyperoxic ventilated ischemia compared with native controls (1.3 +/- 0.2 microM), but did not significantly change under anoxic and hyperoxic ventilation alone. In parallel, under ischemic conditions, oxidized glutathione (GSSG) increased during hyperoxic (3 h: 0.81 +/- 0.04 microM, p <.001), but remained unchanged during anoxic (3 h: 0.31 +/- 0.04 microM) ventilation compared with native controls (0.22 +/- 0.02 microM), whereas F2-isoprostanes were elevated under both hyperoxic (3 h: 63 +/- 15 pM, p <.01) and anoxic (3 h: 50 +/- 9 pM, p <.01) ventilation compared with native controls (16 +/- 4 pM). We conclude that oxidative stress is increased in the lung alveolar lining layer during ischemia, during both anoxic and hyperoxic ventilation. This is paralleled by an increase rather than a decrease in alveolar antioxidant levels, suggested to reflect an adaptive response to oxidative stress during ischemia.
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Affiliation(s)
- Reinhold Schmidt
- Medizinische Klinik II, Zentrum für Innere Medizin, Justus-Liebig-University, Giessen, Germany.
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Dorado-Martínez C, Paredes-Carbajal C, Mascher D, Borgonio-Pérez G, Rivas-Arancibia S. Effects of different ozone doses on memory, motor activity and lipid peroxidation levels, in rats. Int J Neurosci 2002; 108:149-61. [PMID: 11699188 DOI: 10.3109/00207450108986511] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Ozone is one of the main atmospheric pollutants. Its inhalation causes an increase in free radicals, when these free radicals are not compensated by antioxidants, it leads to an oxidative stress state. This oxidative stress state has been implicated in neurodegenerative processes. To determine the effects of oxidative stress caused by exposure to ozone on memory and motor activity, we used 120 male Wistar rats exposed to one of the following ozone doses, (0.0, 0.1, 0.4, 0.7, 1.1 and 1.5 ppm), for four hours. After ozone exposure, short and long term memory of a one trial passive avoidance test were measured, and motor activity was registered for five minutes, in 10 rats of each group. In 16 rats exposed to 0.0, 0.4, 0.7 or 1.1 ppm lipid peroxidation levels from frontal cortex, hippocampus, striatum and cerebellum, were measured. Results show that ozone, causes memory impairment from doses of 0.7 ppm, decrease in motor activity from doses of 1.1 ppm, and increase in lipid peroxidation levels from doses of 0.4 ppm. that increase with the dose.
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Affiliation(s)
- C Dorado-Martínez
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, A. P. 70-250, C. P. 04510 México, D F
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Samet JM, Hatch GE, Horstman D, Steck-Scott S, Arab L, Bromberg PA, Levine M, McDonnell WF, Devlin RB. Effect of antioxidant supplementation on ozone-induced lung injury in human subjects. Am J Respir Crit Care Med 2001; 164:819-25. [PMID: 11549539 DOI: 10.1164/ajrccm.164.5.2008003] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
To determine whether antioxidants can influence human susceptibility to ozone (O(3))-induced changes in lung function and airway inflammation, we placed 31 healthy nonsmoking adults (18 to 35 yr old) on a diet low in ascorbate for 3 wk. At 1 wk, subjects were exposed to filtered air for 2 h while exercising (20 L/min/m(2)), and then underwent bronchoalveolar lavage (BAL) and were randomly assigned to receive either a placebo or 250 mg of vitamin C, 50 IU of alpha-tocopherol, and 12 oz of vegetable cocktail daily for 2 wk. Subjects were then exposed to 0.4 ppm O(3) for 2 h and underwent a second BAL. On the day of the O(3) exposure, supplemented subjects were found to have significantly increased levels of plasma ascorbate, tocopherols, and carotenoids as compared with those of the placebo group. Pulmonary function testing showed that O(3)-induced reductions in FEV(1) and FVC were 30% and 24% smaller, respectively, in the supplemented cohort. In contrast, the inflammatory response to O(3) inhalation, as represented by the percent neutrophils and the concentration of interleukin-6 recovered in the BAL fluid at 1 h after O(3) exposure was not different for the two groups. These data suggest that dietary antioxidants protect against O(3)-induced pulmonary function decrements in humans.
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Affiliation(s)
- J M Samet
- Human Studies Division, National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Research Triangle Park, USA.
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Kodavanti UP, Schladweiler MC, Ledbetter AD, Watkinson WP, Campen MJ, Winsett DW, Richards JR, Crissman KM, Hatch GE, Costa DL. The spontaneously hypertensive rat as a model of human cardiovascular disease: evidence of exacerbated cardiopulmonary injury and oxidative stress from inhaled emission particulate matter. Toxicol Appl Pharmacol 2000; 164:250-63. [PMID: 10799335 DOI: 10.1006/taap.2000.8899] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cardiovascular disease is considered a probable risk factor of particulate matter (PM)-related mortality and morbidity. It was hypothesized that rats with hereditary systemic hypertension and underlying cardiac disease would be more susceptible than healthy normotensive rats to pulmonary injury from inhaled residual oil fly ash (ROFA) PM. Eight spontaneously hypertensive (SH) and eight normotensive Wistar-Kyoto (WKY) rats (12-13 weeks old) were implanted with radiotelemetry transmitters on Day -10 for measurement of electrocardiographic (ECG) waveforms. These and other nonimplanted rats were exposed to filtered air or ROFA (containing leachable toxic levels of metals) on Day 0 by nose-only inhalation (ROFA, 15 mg/m(3) x 6 h/day x 3 days). ECGs were monitored during both exposure and nonexposure periods. At 0 or 18 h post-ROFA exposure, rats were assessed for airway hyperreactivity, pulmonary and cardiac histological lesions, bronchoalveolar lavage fluid (BALF) markers of lung injury, oxidative stress, and cytokine gene expression. Comparisons were made in two areas: (1) underlying cardiopulmonary complications of control SH rats in comparison to control WKY rats; and (2) ROFA-induced cardiopulmonary injury/inflammation and oxidative burden. With respect to the first area, control air-exposed SH rats had higher lung and left ventricular weights when compared to age-matched WKY rats. SH rats had hyporeactive airways to acetylcholine challenge. Lung histology revealed the presence of activated macrophages, neutrophils, and hemorrhage in control SHrats. Consistently, levels of BALF protein, macrophages, neutrophils, and red blood cells were also higher in SH rats. Thiobarbituric acid-reactive material in the BALF of air-exposed SH rats was significantly higher than that of WKY rats. Lung inflammation and lesions were mirrored in the higher basal levels of pulmonary cytokine mRNA expression. Cardiomyopathy and monocytic cell infiltration were apparent in the left ventricle of SH rats, along with increased cytokine expression. ECG demonstrated a depressed ST segment area in SH rats. With regard to the second area of comparison (ROFA-exposed rats), pulmonary histology indicated a slightly exacerbated pulmonary lesions including inflammatory response to ROFA in SH rats compared to WKY rats and ROFA-induced increases in BALF protein and albumin were significantly higher in SH rats than in WKY rats. In addition, ROFA caused an increase in BALF red blood cells in SH rats, indicating increased hemorrhage in the alveolar parenchyma. The number of alveolar macrophages increased more dramatically in SH rats following ROFA exposure, whereas neutrophils increased similarly in both strains. Despite greater pulmonary injury in SH rats, ROFA-induced increases in BALF GSH, ascorbate, and uric acid were attenuated when compared to WKY rats. ROFA inhalation exposure was associated with similar increases in pulmonary mRNA expression of IL-6, cellular fibronectin, and glucose-6-phosphate dehydrogenase (relative to that of beta-actin) in both rat strains. The expression of MIP-2 was increased in WKY but attenuated in SH rats. Thus, SH rats have underlying cardiac and pulmonary complications. When exposed to ROFA, SH rats exhibited exacerbated pulmonary injury, an attenuated antioxidant response, and acute depression in ST segment area of ECG, which is consistent with a greater susceptibility to adverse health effects of fugitive combustion PM. This study shows that the SH rat is a potentially useful model of genetically determined susceptibility with pulmonary and cardiovascular complications.
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Affiliation(s)
- U P Kodavanti
- Pulmonary Toxicology Branch, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, 27711, USA
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Vargas MH, Romero L, Sommer B, Zamudio P, Gustin P, Montaño LM. Chronic exposure to ozone causes tolerance to airway hyperresponsiveness in guinea pigs: lack of SOD role. J Appl Physiol (1985) 1998; 84:1749-55. [PMID: 9572826 DOI: 10.1152/jappl.1998.84.5.1749] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Tolerance to respiratory effects of O3 has been demonstrated for anatomic and functional changes, but information about tolerance to O3-induced airway hyperresponsiveness (AHR) is scarce. In guinea pigs exposed to air or O3 (0.3 parts/million, 4 h/day, for 1, 3, 6, 12, 24, or 48 days, studied 16-18 h later), pulmonary insufflation pressure changes induced by intravenous substance P (SP, 0.032-3.2 micro ug/kg) were measured, then the animals were subjected to bronchoalveolar lavage (BAL). Bronchial rings with or without phosphoramidon were also evaluated 3 h after air or a single O3 exposure. O3 caused in vivo AHR (increased sensitivity) to SP after 1, 3, 6, 12, and 24 days of exposure compared with control. However, after 48 days of exposure, O3 no longer caused AHR. Total cell, macrophage, neutrophil, and eosinophil counts in BAL were increased in most O3-exposed groups. When data from all animals were pooled, we found a highly significant correlation between degree of airway responsiveness and total cells (r = 0.55), macrophages (r = 0.54), neutrophils (r = 0.47), and eosinophils (r = 0.53), suggesting that airway inflammation is involved in development of AHR to SP. Superoxide dismutase (SOD) levels in BAL fluids were increased (P < 0.05) after 1, 3, 6, and 12 days of O3 exposure and returned to basal levels after 24 and 48 days of exposure. O3 failed to induce hyperresponsiveness to SP in bronchial rings, and phosphoramidon increased responses to SP in air- and O3-exposed groups, suggesting that neutral endopeptidase inactivation was not involved in O3-induced AHR to SP in vivo. We conclude that chronic exposure to 0. 3 ppm O3, a concentration found in highly polluted cities, resulted in tolerance to AHR to SP in guinea pigs by an SOD-independent mechanism.
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Affiliation(s)
- M H Vargas
- Departamento de Investigación en Asma, Instituto Nacional de Enfermedades Respiratorias, Mexico
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Abstract
The objective of this study was to determine the impact of limited ascorbate (Asc) availability on type II cell sensitivity to oxidant stress. Guinea pigs were fed diets with or without Asc for 18 days, and type II cells were isolated. Although lung Asc was decreased by 90% in deficient animals (scorbutic), type II cell Asc was decreased by 50%. Upon treatment with 250 microM H2O2, the necrotic injury was twofold greater in scorbutic cells compared with control cells. With 100 microM H2O2 treatment, apoptotic injury was twofold greater in scorbutic cells compared with control cells. Although there was less necrotic injury in cells exposed to 95% O2, the scorbutic cells were more sensitive than control cells. Asc pretreatment protected against necrosis and apoptosis. The Asc analog isoascorbate provided partial protection and suggested that part of the protection was not chemical detoxification but was Asc specific. We conclude that limited Asc availability resulted in a functional type II cell but a cell more sensitive to oxidant-induced injury.
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Affiliation(s)
- L A Brown
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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Wiester MJ, Watkinson WP, Costa DL, Crissman KM, Richards JH, Winsett DW, Highfill JW. Ozone toxicity in the rat. III. Effect of changes in ambient temperature on pulmonary parameters. J Appl Physiol (1985) 1996; 81:1691-700. [PMID: 8904588 DOI: 10.1152/jappl.1996.81.4.1691] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Pulmonary toxicity of ozone (O3) was examined in adult male Fischer 344 rats exposed to 0.5 parts/million O3 for either 6 or 23 h/day over 5 days while maintained at an ambient temperature (Ta) of either 10, 22, or 34 degrees C. Toxicity was evaluated by using changes in lung volumes and the concentrations of constituents of bronchoalveolar lavage fluid that signal lung injury and/or inflammation. Results indicated that toxicity increased as Ta decreased. Exposures conducted at 10 degrees C were associated with the greatest decreases in body weight and total lung capacity and the greatest increases in lavageable protein, lysozyme, alkaline phosphatase activity, and percent neutrophils. O3 effects not modified by Ta included increases in residual volume and lavageable potassium, glucose, urea, and ascorbic acid with exposure at 34 degrees C. Most effects were attenuated during the 5 exposure days and/or returned to normal levels after 7 air recovery days, regardless of prior O3 exposure or Ta. It is possible that Ta-induced changes in metabolic rate may have altered ventilation and, therefore, the O3 doses among rats exposed at the three different Ta levels.
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Affiliation(s)
- M J Wiester
- Pulmonary Toxicology Branch, United States Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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Kodavanti UP, Costa DL, Richards J, Crissman KM, Slade R, Hatch GE. Antioxidants in bronchoalveolar lavage fluid cells isolated from ozone--exposed normal and ascorbate-deficient guinea pigs. Exp Lung Res 1996; 22:435-48. [PMID: 8872087 DOI: 10.3109/01902149609046034] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Previous studies have indicated that systemic deficiency in one of the critical antioxidants, ascorbate, does not significantly exacerbate ozone-induced lung injury and changes in lung antioxidants following longer-term exposure. Because alveolar cells encounter the highest ozone dose upon exposure and lack direct blood supply, systemic ascorbate deficiency may exacerbate ozone response on antioxidants within these cells. Female Hartley guinea pigs (30 days old) were fed either a regular guinea pig chow or chow that lacked ascorbate. The dietary regimen was started 1 week prior to exposure, continued through ozone exposure (0, 0.2, 0.4, or 0.8 ppm, 23 h/day, 1 week), and during 1 week recovery in clean air following exposure. Immediately after 1 week of exposure or recovery, lungs were lavaged and cells were counted in bronchoalveolar lavage fluid (BALF). Protein, ascorbate, uric acid, total glutathione (GSH), and alpha-tocopherol were analyzed in these cells. Ozone caused an increase in total BALF cells and total cellular protein after 0.4 and 0.8 ppm ozone. The increase was more pronounced in ascorbate-deficient guinea pigs. Protein per million cells, however, was not changed by ozone or diet. In ascorbate-sufficient guinea pigs, ascorbate levels were increased only after 0.2 ppm ozone. However, uric acid (at 0.4 and 0.8 ppm ozone) and GSH (at all concentrations of ozone) levels were increased in both dietary groups. Ascorbate deficiency did not affect basal uric acid or GSH levels in BALF cells. There was a small diet-related depletion in cellular alpha-tocopherol. Ozone exposure also decreased alpha-tocopherol regardless of diet. The above changes except for alpha-tocopherol appeared to be reversed after 1 week of recovery in both dietary groups. In summary, ozone is capable of inducing a mechanism that increases antioxidants such as ascorbate, GSH, and uric acid. GSH and uric acid are not affected by ascorbate deficiency, but alpha-tocopherol is depleted. GSH and uric acid may be critical in ozone-induced adaptation during ascorbate deficiency.
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Affiliation(s)
- U P Kodavanti
- Pulmonary Toxicology Branch, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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