1
|
Pan S, Karey E, Nieves-Cintron M, Chen YJ, Hwang SH, Hammock BD, Pinkerton KE, Chen CY. Effects of chronic secondhand smoke exposure on cardiovascular regulation and the role of soluble epoxide hydrolase in mice. Front Physiol 2023; 14:1185744. [PMID: 37362438 PMCID: PMC10285070 DOI: 10.3389/fphys.2023.1185744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/30/2023] [Indexed: 06/28/2023] Open
Abstract
Background: Secondhand smoke (SHS) is a significant risk factor for cardiovascular morbidity and mortality with an estimated 80% of SHS-related deaths attributed to cardiovascular causes. Public health measures and smoking bans have been successful both in reducing SHS exposure and improving cardiovascular outcomes in non-smokers. Soluble epoxide hydrolase (sEH) inhibitors have been shown to attenuate tobacco exposure-induced lung inflammatory responses, making them a promising target for mitigating SHS exposure-induced cardiovascular outcomes. Objectives: The objectives of this study were to determine 1) effects of environmentally relevant SHS exposure on cardiac autonomic function and blood pressure (BP) regulation and 2) whether prophylactic administration of an sEH inhibitor (TPPU) can reduce the adverse cardiovascular effects of SHS exposure. Methods: Male C57BL/6J mice (11 weeks old) implanted with BP/electrocardiogram (ECG) telemetry devices were exposed to filtered air or 3 mg/m3 of SHS (6 hr/d, 5 d/wk) for 12 weeks, followed by 4 weeks of recovery in filtered air. Some mice received TPPU in drinking water (15 mg/L) throughout SHS exposure. BP, heart rate (HR), HR variability (HRV), baroreflex sensitivity (BRS), and BP variability were determined monthly. Results: SHS exposure significantly decreased 1) short-term HRV by ∼20% (p < 0.05) within 4 weeks; 2) overall HRV with maximum effect at 12 weeks (-15%, p < 0.05); 3) pulse pressure (-8%, p < 0.05) as early as week 4; and 4) BRS with maximum effect at 12 weeks (-11%, p < 0.05). Four weeks of recovery following 12 weeks of SHS ameliorated all SHS-induced cardiovascular detriments. Importantly, mice exposed to TPPU in drinking water during SHS-related exposure were protected from SHS cardiovascular consequences. Discussion: The data suggest that 1) environmental relevant SHS exposure significantly alters cardiac autonomic function and BP regulation; 2) cardiovascular consequences from SHS can be reversed by discontinuing SHS exposure; and 3) inhibiting sEH can prevent SHS-induced cardiovascular consequences.
Collapse
Affiliation(s)
- Shiyue Pan
- Department of Pharmacology, University of California Davis, Davis, CA, United States
| | - Emma Karey
- Department of Pharmacology, University of California Davis, Davis, CA, United States
| | | | - Yi-Je Chen
- Department of Pharmacology, University of California Davis, Davis, CA, United States
| | - Sung Hee Hwang
- Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA, United States
| | - Bruce D. Hammock
- Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA, United States
| | - Kent E. Pinkerton
- Center for Health and the Environment, University of California Davis, Davis, CA, United States
| | - Chao-Yin Chen
- Department of Pharmacology, University of California Davis, Davis, CA, United States
| |
Collapse
|
2
|
Yang S, Liang X, Dou Q, La Y, Cai J, Yang J, Laba C, Liu Q, Guo B, Yu W, Wang Q, Chen G, Hong F, Jia P, Zhao X. Ethnic disparities in the association between ambient air pollution and risk for cardiometabolic abnormalities in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:155940. [PMID: 35580681 DOI: 10.1016/j.scitotenv.2022.155940] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/02/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Long-term exposure to ambient air pollution has been associated with cardiometabolic abnormalities (CAs), which, however, may be stronger in vulnerable populations, such as minorities. The variation of the association between ambient air pollution and CAs between the majority (Han) and minority populations in China have been poorly studied. OBJECTIVES We aimed to estimate and compare the Hans' and minorities' risks for CAs associated with long-term exposure to ambient air pollution in Southwest China. METHODS A cross-sectional study was conducted on the basis of the China Multi-Ethnic Cohort. CAs were defined by the presence of at least three pre-defined metabolic dysfunctions (central obesity, elevated triglycerides, reduced high-density lipoprotein cholesterol, elevated blood pressure, and elevated fasting glucose). The concentrations of ambient air pollutants, including particulate matters (PM1, PM2.5, and PM10) and nitrogen dioxide (NO2), were generated from random forest models on the basis of multi-source data. One- and two-pollutant regression models were fit to assess associations between air pollutant exposure and CA risks. Sensitivity analyses were performed to examine the robustness of the associations. RESULTS The final sample included 51,037 Hans and 28,702 minority participants. The prevalence of CAs was 25.0%, slightly higher in the minorities (25.5%) than the Hans (24.4%). The higher risks for CAs in the overall population were associated with each 10 μg/m3 increase in the exposure to PM1 (OR = 1.07 [1.05-1.09]), PM2.5 (OR = 1.11 [1.06-1.17]), PM10 (OR = 1.04 [1.03-1.06]), and NO2 (OR = 1.04 [1.03-1.07]). Compared to the Hans, the higher risks for CAs were observed in the minorities for PM1 (OR = 1.35 [1.18-1.53]), PM2.5 (OR = 1.61 [1.34-1.93]), and PM10 (OR = 1.15 [1.07-1.23]). The associations of metabolic dysfunctions (CA components) with ambient air pollution also varied between the Han and minority populations. CONCLUSIONS The associations between exposure to ambient air pollution and CA risks were stronger in the minorities than Hans. Our findings provide a better understanding of ethnic disparities in CA risks when being exposed to ambient air pollution in China, which also have important implications for other low- and middle-income countries where less health resources (e.g., cohort populations) are available to conduct such studies.
Collapse
Affiliation(s)
- Shujuan Yang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; International Institute of Spatial Lifecourse Health (ISLE), Wuhan University, Wuhan, China
| | - Xian Liang
- Chengdu Center for Disease Control and Prevention, Chengdu, China
| | - Qingyu Dou
- National Clinical Research Center of Geriatrics, Geriatric Medicine Center, West China Hospital, Sichuan University, Chengdu, China; International Institute of Spatial Lifecourse Health (ISLE), Wuhan University, Wuhan, China
| | - Yang La
- Tibet University, Lhasa, China
| | - Jiaojiao Cai
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing, China
| | - Jun Yang
- Yunnan Center for Disease Control and Prevention, Kunming, China
| | - Ciren Laba
- Tibet Center for Disease Control and Prevention, Lhasa, China
| | - Qiaolan Liu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Bing Guo
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Wanqi Yu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Qinjian Wang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Gongbo Chen
- Guangzhou Key Laboratory of Environmental Pollution and Health Risk Assessment, Guangdong Provincial Engineering Technology Research Center of Environmental and Health risk Assessment, Department of Preventive Medicine, School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Feng Hong
- School of Public Health, The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang, China.
| | - Peng Jia
- International Institute of Spatial Lifecourse Health (ISLE), Wuhan University, Wuhan, China; School of Resource and Environmental Sciences, Wuhan University, Wuhan, China.
| | - Xing Zhao
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China.
| |
Collapse
|
3
|
Sun J, Pan S, Karey E, Chen YJ, Pinkerton KE, Wilson CG, Chen CY. Secondhand Smoke Decreased Excitability and Altered Action Potential Characteristics of Cardiac Vagal Neurons in Mice. Front Physiol 2021; 12:727000. [PMID: 34630146 PMCID: PMC8498211 DOI: 10.3389/fphys.2021.727000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/30/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Secondhand smoke (SHS), a major indoor pollutant, is a significant risk factor for cardiovascular morbidity and mortality including arrhythmias and sudden cardiac death. Exposure to SHS can produce autonomic imbalance, as evidenced by reduced heart rate variability (HRV)—a clinical metric of cardiac vagal regulation. Currently, the mechanisms through which SHS changes the vagal preganglionic neuronal inputs to the heart to produce this remains unknown. Objectives: To characterize the effect of SHS on both the excitability and action potential (AP) characteristics of anatomically identified cardiac vagal neurons (CVNs) in the nucleus ambiguus and examine whether SHS alters small conductance calcium-activated potassium (SK) channel activity of these CVNs. Methods: Adult male mice were exposed to four weeks of filtered air or SHS (3 mg/m3) 6 h/day, 5 day/week. Using patch-clamp recordings on identified CVNs in brainstem slices, we determined neuronal excitability and AP characteristics with depolarizing step- and ramp-current injections. Results: Four weeks of SHS exposure reduced spiking responses to depolarizing current injections and increased AP voltage threshold in CVNs. Perfusion with apamin (20 nM) magnified these SHS-induced effects, suggesting reduced SK channel activity may serve to minimize the SHS-induced decreases in CVNs excitability. Medium afterhyperpolarization (a measurement of SK channel activity) was smaller in the SHS group, further supporting a lower SK channel activity. AP amplitude, rise rate, fast afterhyperpolarization amplitude (a measurement of voltage-gated channel activity), and decay rate were higher in the SHS group at membrane voltages more positive to 0 mV, suggesting altered inactivation properties of voltage-dependent channels underlying APs. Discussion: SHS exposure reduced neuronal excitability of CVNs with compensatory attenuation of SK channel activity and altered AP characteristics. Neuroplasticity of CVNs could blunt regulatory cardiac vagal signaling and contribute to the cardiovascular consequences associated with SHS exposure, including reduced HRV.
Collapse
Affiliation(s)
- Junqing Sun
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Shiyue Pan
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Emma Karey
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Yi-Je Chen
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Kent E Pinkerton
- Department of Pediatrics and Center for Health and the Environment, University of California, Davis, Davis, CA, United States
| | - Christopher G Wilson
- Department of Basic Sciences, Loma Linda University, Loma Linda, CA, United States
| | - Chao-Yin Chen
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| |
Collapse
|
4
|
Environmentally Relevant Iron Oxide Nanoparticles Produce Limited Acute Pulmonary Effects in Rats at Realistic Exposure Levels. Int J Mol Sci 2021; 22:ijms22020556. [PMID: 33429876 PMCID: PMC7827273 DOI: 10.3390/ijms22020556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 12/24/2022] Open
Abstract
Iron is typically the dominant metal in the ultrafine fraction of airborne particulate matter. Various studies have investigated the toxicity of inhaled nano-sized iron oxide particles (FeOxNPs) but their results have been contradictory, with some indicating no or minor effects and others finding effects including oxidative stress and inflammation. Most studies, however, did not use materials reflecting the characteristics of FeOxNPs present in the environment. We, therefore, analysed the potential toxicity of FeOxNPs of different forms (Fe3O4, α-Fe2O3 and γ-Fe2O3) reflecting the characteristics of high iron content nano-sized particles sampled from the environment, both individually and in a mixture (FeOx-mix). A preliminary in vitro study indicated Fe3O4 and FeOx-mix were more cytotoxic than either form of Fe2O3 in human bronchial epithelial cells (BEAS-2B). Follow-up in vitro (0.003, 0.03, 0.3 µg/mL, 24 h) and in vivo (Sprague–Dawley rats, nose-only exposure, 50 µg/m3 and 500 µg/m3, 3 h/d × 3 d) studies therefore focused on these materials. Experiments in vitro explored responses at the molecular level via multi-omics analyses at concentrations below those at which significant cytotoxicity was evident to avoid detection of responses secondary to toxicity. Inhalation experiments used aerosol concentrations chosen to produce similar levels of particle deposition on the airway surface as were delivered in vitro. These were markedly higher than environmental concentrations. No clinical signs of toxicity were seen nor effects on BALF cell counts or LDH levels. There were also no significant changes in transcriptomic or metabolomic responses in lung or BEAS-2B cells to suggest adverse effects.
Collapse
|
5
|
Abstract
Air pollutants pose a serious worldwide health hazard, causing respiratory and cardiovascular morbidity and mortality. Pollutants perturb the autonomic nervous system, whose function is critical to cardiopulmonary homeostasis. Recent studies suggest that pollutants can stimulate defensive sensory nerves within the cardiopulmonary system, thus providing a possible mechanism for pollutant-induced autonomic dysfunction. A better understanding of the mechanisms involved would likely improve the management and treatment of pollution-related disease.
Collapse
Affiliation(s)
- Thomas E Taylor-Clark
- Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| |
Collapse
|
6
|
Huang F, Wang P, Pan X, Wang Y, Ren S. Effects of short-term exposure to particulate matters on heart rate variability: A systematic review and meta-analysis based on controlled animal studies. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 256:113306. [PMID: 31733955 DOI: 10.1016/j.envpol.2019.113306] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/21/2019] [Accepted: 09/24/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Exposure to particulate matters (PM) is recognized as an important risk factor for cardiovascular disease. A change in cardiac autonomic function is one postulated mechanism leading to PM related cardiovascular events. This study therefore evaluated the associations of short-term exposure to PM and heart rate variability (HRV) parameters, which can reflect the cardiac autonomic function. METHODS Four electronic databases were searched for controlled studies of rodents published prior to December 2018. A systematic review and meta-analysis was conducted. Effect sizes were calculated for five main HRV parameters, including standard deviation of normal-to-normal intervals (SDNN), square root of mean squared differences between successive normal-to-normal intervals (rMSSD), low frequency (LF), high frequency (HF), and the ratio of LF and HF (LF/HF). RESULTS The review included 23 studies with 401 animals. Short-term exposure to PM by instillation yielded statistically significant effects on SDNN (Standardized Mean Difference [SMD] = -1.11, 95% Confidence Intervals [CI] = -2.22 to -0.01, P = 0.05), LF (SMD = -1.19, 95% CI = -1.99 to -0.40, P = 0.003) and LF/HF (SMD = -1.05, 95% CI = -2.03 to -0.07, P = 0.04). Short-term exposure to PM by inhalation only yielded statistically significant effect on LF/HF (SMD = -0.83, 95% CI = -1.39 to -0.27, P = 0.004). There was no evidence that animal model and exposure frequency influenced the relationship of PM and HRV. CONCLUSIONS Short-term exposure to PM can decrease HRV of rodents, affecting cardiac autonomic function. Exposure methods can influence the relationships of PM and HRV parameters. Further studies should focus on the effects of long-term PM exposure, on human beings, and potential influential factors of PM-HRV associations.
Collapse
Affiliation(s)
- Fangfang Huang
- Medical College, Henan University of Science and Technology, Luoyang, China
| | - Ping Wang
- Medical College, Henan University of Science and Technology, Luoyang, China
| | - Xinjuan Pan
- Medical College, Henan University of Science and Technology, Luoyang, China
| | - Yingfang Wang
- Medical College, Henan University of Science and Technology, Luoyang, China
| | - Shuai Ren
- Luoyang Fifth People's Hospital, The Fifth Affiliated Hospital of Henan University of Science and Technology, Luoyang, China.
| |
Collapse
|
7
|
Pinkerton KE, Chen CY, Mack SM, Upadhyay P, Wu CW, Yuan W. Cardiopulmonary Health Effects of Airborne Particulate Matter: Correlating Animal Toxicology to Human Epidemiology. Toxicol Pathol 2019; 47:954-961. [PMID: 31645209 DOI: 10.1177/0192623319879091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The effects of particulate matter (PM) on cardiopulmonary health have been studied extensively over the past three decades. Particulate matter is the primary criteria air pollutant most commonly associated with adverse health effects on the cardiovascular and respiratory systems. The mechanisms by which PM exerts its effects are thought to be due to a variety of factors which may include, but are not limited to, concentration, duration of exposure, and age of exposed persons. Adverse effects of PM are strongly driven by their physicochemical properties, sites of deposition, and interactions with cells of the respiratory and cardiovascular systems. The direct translocation of particles, as well as neural and local inflammatory events, are primary drivers for the observed cardiopulmonary health effects. In this review, toxicological studies in animals, and clinical and epidemiological studies in humans are examined to demonstrate the importance of using all three approaches to better define potential mechanisms driving health outcomes upon exposure to airborne PM of diverse physicochemical compositions.
Collapse
Affiliation(s)
- Kent E Pinkerton
- Center for Health and the Environment, University of California, Davis, USA
| | - Chao-Yin Chen
- Department of Pharmacology, University of California, Davis, USA
| | - Savannah M Mack
- Center for Health and the Environment, University of California, Davis, USA
| | - Priya Upadhyay
- Center for Health and the Environment, University of California, Davis, USA
| | - Ching-Wen Wu
- Center for Health and the Environment, University of California, Davis, USA
| | - Wanjun Yuan
- Center for Health and the Environment, University of California, Davis, USA.,College of Environmental & Resource Sciences, Shanxi University, Taiyuan, Shanxi, China
| |
Collapse
|
8
|
Karey E, Pan S, Morris AN, Bruun DA, Lein PJ, Chen CY. The Use of Percent Change in RR Interval for Data Exclusion in Analyzing 24-h Time Domain Heart Rate Variability in Rodents. Front Physiol 2019; 10:693. [PMID: 31244671 PMCID: PMC6562196 DOI: 10.3389/fphys.2019.00693] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 05/16/2019] [Indexed: 11/13/2022] Open
Abstract
While epidemiological data support the link between reduced heart rate variability (HRV) and a multitude of pathologies, the mechanisms underlying changes in HRV and disease progression are poorly understood. Even though we have numerous rodent models of disease for mechanistic studies, not being able to reliably measure HRV in conscious, freely moving rodents has hindered our ability to extrapolate the role of HRV in the progression from normal physiology to pathology. The sheer number of heart beats per day (>800,000 in mice) makes data exclusion both time consuming and daunting. We sought to evaluate an RR interval exclusion method based on percent (%) change of adjacent RR intervals. Two approaches were evaluated: % change from “either” and “both” adjacent RR intervals. The data exclusion method based on standard deviation (SD) was also evaluated for comparison. Receiver operating characteristic (ROC) curves were generated to determine the performance of each method. Results showed that exclusion based on % change from “either” adjacent RR intervals was the most accurate method in identifying normal and abnormal RR intervals, with an overall accuracy of 0.92–0.99. As the exclusion value increased (% change or SD), the sensitivity (correctly including normal RR intervals) increased exponentially while the specificity (correctly rejecting abnormal RR intervals) decreased linearly. Compared to the SD method, the “either” approach had a steeper rise in sensitivity and a more gradual decrease in specificity. The intersection of sensitivity and specificity where the exclusion criterion had the same accuracy in identifying normal and abnormal RR intervals was 10–20% change for the “either” approach and ∼ 1 SD for the SD-based exclusion method. Graphically (tachogram and Lorenz plot), 20% change from either adjacent RR interval resembled the data after manual exclusion. Finally, overall (SDNN) and short-term (rMSSD) indices of HRV generated using 20% change from “either” adjacent RR intervals as the exclusion criterion were closer to the manual exclusion method with lower subject-to-subject variability than those generated using the 2 SD exclusion criterion. Thus, 20% change from “either” adjacent RR intervals is a good criterion for data exclusion for reliable 24-h time domain HRV analysis in rodents.
Collapse
Affiliation(s)
- Emma Karey
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States
| | - Shiyue Pan
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States
| | - Amber N Morris
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States
| | - Donald A Bruun
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Chao-Yin Chen
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States
| |
Collapse
|
9
|
Conklin DJ, Schick S, Blaha MJ, Carll A, DeFilippis A, Ganz P, Hall ME, Hamburg N, O'Toole T, Reynolds L, Srivastava S, Bhatnagar A. Cardiovascular injury induced by tobacco products: assessment of risk factors and biomarkers of harm. A Tobacco Centers of Regulatory Science compilation. Am J Physiol Heart Circ Physiol 2019; 316:H801-H827. [PMID: 30707616 PMCID: PMC6483019 DOI: 10.1152/ajpheart.00591.2018] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 01/09/2019] [Accepted: 01/27/2019] [Indexed: 02/07/2023]
Abstract
Although substantial evidence shows that smoking is positively and robustly associated with cardiovascular disease (CVD), the CVD risk associated with the use of new and emerging tobacco products, such as electronic cigarettes, hookah, and heat-not-burn products, remains unclear. This uncertainty stems from lack of knowledge on how the use of these products affects cardiovascular health. Cardiovascular injury associated with the use of new tobacco products could be evaluated by measuring changes in biomarkers of cardiovascular harm that are sensitive to the use of combustible cigarettes. Such cardiovascular injury could be indexed at several levels. Preclinical changes contributing to the pathogenesis of disease could be monitored by measuring changes in systemic inflammation and oxidative stress, organ-specific dysfunctions could be gauged by measuring endothelial function (flow-mediated dilation), platelet aggregation, and arterial stiffness, and organ-specific injury could be evaluated by measuring endothelial microparticles and platelet-leukocyte aggregates. Classical risk factors, such as blood pressure, circulating lipoproteins, and insulin resistance, provide robust estimates of risk, and subclinical disease progression could be followed by measuring coronary artery Ca2+ and carotid intima-media thickness. Given that several of these biomarkers are well-established predictors of major cardiovascular events, the association of these biomarkers with the use of new and emerging tobacco products could be indicative of both individual and population-level CVD risk associated with the use of these products. Differential effects of tobacco products (conventional vs. new and emerging products) on different indexes of cardiovascular injury could also provide insights into mechanisms by which they induce cardiovascular harm.
Collapse
Affiliation(s)
- Daniel J Conklin
- Diabetes and Obesity Center, University of Louisville , Louisville, Kentucky
| | - Suzaynn Schick
- Department of Medicine, University of California-San Francisco , San Francisco, California
| | - Michael J Blaha
- Ciccarone Center for the Prevention of Heart Disease, Department of Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Alex Carll
- Diabetes and Obesity Center, University of Louisville , Louisville, Kentucky
| | - Andrew DeFilippis
- Diabetes and Obesity Center, University of Louisville , Louisville, Kentucky
| | - Peter Ganz
- Department of Medicine, University of California-San Francisco , San Francisco, California
| | - Michael E Hall
- Department of Physiology and Biophysics, University of Mississippi Medical Center , Jackson, Mississippi
| | - Naomi Hamburg
- Department of Medicine/Cardiovascular Medicine, School of Medicine, Boston University , Boston, Massachusetts
| | - Tim O'Toole
- Diabetes and Obesity Center, University of Louisville , Louisville, Kentucky
| | - Lindsay Reynolds
- Department of Epidemiology and Prevention, Wake Forest School of Medicine , Winston-Salem, North Carolina
| | - Sanjay Srivastava
- Diabetes and Obesity Center, University of Louisville , Louisville, Kentucky
| | - Aruni Bhatnagar
- Diabetes and Obesity Center, University of Louisville , Louisville, Kentucky
| |
Collapse
|
10
|
Kurhanewicz N, Ledbetter A, Farraj A, Hazari M. TRPA1 mediates the cardiac effects of acrolein through parasympathetic dominance but also sympathetic modulation in mice. Toxicol Appl Pharmacol 2018; 347:104-114. [PMID: 29627347 DOI: 10.1016/j.taap.2018.03.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 02/27/2018] [Accepted: 03/22/2018] [Indexed: 12/12/2022]
Abstract
Numerous studies have demonstrated that short-term air pollution exposure causes cardiac autonomic imbalance as measured by heart rate variability (HRV). We previously showed that a single exposure to acrolein, a ubiquitous gaseous component of air pollution, not only causes autonomic imbalance, but also increases arrhythmia through transient receptor potential A1 (TRPA1) cation channels. Thus, the goal of this study was to characterize acrolein-induced autonomic changes in both normal and TRPA1-knockout mice (KO). Conscious, unrestrained C57BL/6 (WT) and KO mice were exposed to 3 ppm acrolein for 3 h. Separate groups were treated with either atenolol (sympathetic blocker), atropine (parasympathetic blocker) or hexamethonium (autonomic neurotransmission blocker), immediately before exposure. Electrocardiogram (ECG) and heart rate (HR) were recorded continuously before, during and after exposure. Exposure to acrolein produced significant increases in standard deviation of normal-to-normal R-R intervals (SDNN), Root Mean Square of the Successive Differences (RMSSD) and Low-Frequency (LF), as well as an increase in arrhythmia in WT mice. Treatment with atenolol reduced this response while atropine enhanced it, and both drugs blocked the acrolein-induced increase in arrhythmia; hexamethonium had no effect. On the other hand, neither acrolein nor any drug had an effect in the KO mice. Thus, acrolein-induced HRV responses appear to be mediated by a combined parasympathetic and sympathetic modulation. KO mice did not demonstrate any increases in HRV with exposure to acrolein. These data demonstrate that the cardiac effects of irritant air pollutants likely involve disruption of homeostatic balance and altered regulation even in healthy animals.
Collapse
Affiliation(s)
- Nicole Kurhanewicz
- Curriciulm in Toxicology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Allen Ledbetter
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711, United States
| | - Aimen Farraj
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711, United States
| | - Mehdi Hazari
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711, United States.
| |
Collapse
|
11
|
Stratford K, Haykal-Coates N, Thompson L, Krantz QT, King C, Krug J, Gilmour MI, Farraj A, Hazari M. Early-Life Persistent Vitamin D Deficiency Alters Cardiopulmonary Responses to Particulate Matter-Enhanced Atmospheric Smog in Adult Mice. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:3054-3061. [PMID: 29382191 PMCID: PMC8006180 DOI: 10.1021/acs.est.7b04882] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Early life nutritional deficiencies can lead to increased cardiovascular susceptibility to environmental exposures. Thus, the purpose of this study was to examine the effect of early life persistent vitamin D deficiency (VDD) on the cardiopulmonary response to a particulate matter-enhanced photochemical smog. Mice were fed a VDD or normal diet (ND) after weaning. At 17 weeks of age, mice were implanted with radiotelemeters to monitor electrocardiogram, heart rate (HR), and heart rate variability (HRV). Ventilatory function was measured throughout the diet before and after smog exposure using whole-body plethysmography. VDD mice had lower HR, increased HRV, and decreased tidal volume compared with ND. Regardless of diet, HR decreased during air exposure; this response was blunted by smog in ND mice and to a lesser degree in VDD. When compared with ND, VDD increased HRV during air exposure and more so with smog. However, smog only increased cardiac arrhythmias in ND mice. This study demonstrates that VDD alters the cardiopulmonary response to smog, highlighting the possible influence of nutritional factors in determining responses to air pollution. The mechanism of how VDD induces these effects is currently unknown, but modifiable factors should be considered when performing risk assessment of complex air pollution atmospheres.
Collapse
Affiliation(s)
- Kimberly Stratford
- Curriculum in Toxicology, University of North Carolina – Chapel Hill, Chapel Hill, NC, 27599
| | - Najwa Haykal-Coates
- Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711
| | - Leslie Thompson
- Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711
| | - Q. Todd Krantz
- Inhalation Toxicology Facilities Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711
| | - Charly King
- Inhalation Toxicology Facilities Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711
| | - Jonathan Krug
- Exposure Methods and Measurement Division, National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711
| | - M. Ian Gilmour
- Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711
| | - Aimen Farraj
- Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711
| | - Mehdi Hazari
- Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711
- Corresponding author: Mehdi S. Hazari, Environmental Public Health Division, USEPA, 109 Alexander Drive, B105; Research Triangle Park, NC 27711; (Phone: 919-541-4588; Fax: 919-541-0034; )
| |
Collapse
|
12
|
Chuang HC, Lin YJ, Chou CCK, Hwang JS, Chen CC, Yan YH, Hsieh HI, Chuang KJ, Cheng TJ. Alterations in cardiovascular function by particulate matter in rats using a crossover design. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 231:812-820. [PMID: 28866422 DOI: 10.1016/j.envpol.2017.08.082] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 08/21/2017] [Accepted: 08/21/2017] [Indexed: 06/07/2023]
Abstract
The objective of this study was to investigate associations between cardiovascular effects and urban ambient particle constituents using an in vivo crossover experimental design. Ambient particles were introduced to an exposure chamber for whole-body exposure of WKY rats, where the particulate matter with an aerodynamic diameter of <2.5 μm (PM2.5) mass concentration, particle number concentration, and black carbon (BC) were monitored. Organic carbon (OC), elemental carbon (EC), and soluble ions of PM2.5 were determined. In a crossover design, rats were exposed to ambient particles or high-efficiency particle arrestance (HEPA)-filtered control air for 7 days following a 7-day washout interval. The crossover exposure between particles and HEPA-filtered air was repeated 4 times. Radiotelemetric data on blood pressure (BP) [systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP), and mean arterial pressure (MAP)], heart rate (HR), and heart rate viability (HRV) were subsequently obtained during the entire study. Exposure to the PM2.5 mass concentration was associated with decreases in the SBP, DBP, MAP, and HR (p < 0.05), whereas no significant changes in the BP or HR occurred with the particle number or black carbon. For HRV, the ln 5-min standard deviation of the normal-to-normal (NN) interval (LnSDNN) and the ln root mean square of successive differences in adjacent NN intervals (LnRMSSD) were positively associated with the PM2.5 mass concentration (p < 0.05). There were no significant effects of the particle number concentration or BC on HRV. Alterations in the HR were associated with OC, EC, Na+, Cl-, and NO3-. Cl- was associated with the DBP, MAP, HR, SDNN, and RMSSD. NO3- was correlated with the SBP, MAP, HR, SDNN, and RMSSD. In conclusion, we observed cardiovascular responses to ambient particles in vivo using a crossover design which can reduce animal use in future environmental studies.
Collapse
Affiliation(s)
- Hsiao-Chi Chuang
- School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.
| | - Yin-Jyun Lin
- Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan.
| | - Charles C K Chou
- Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan.
| | | | - Chu-Chih Chen
- Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan.
| | - Yuan-Horng Yan
- Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan; Department of Medical Research, Kuang Tien General Hospital, Taichung, Taiwan.
| | - Hui-I Hsieh
- Department of Family Medicine, Cathay General Hospital, New Taipei City, Taiwan.
| | - Kai-Jen Chuang
- Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; School of Public Health, College of Public Health, Taipei Medical University, Taipei, Taiwan.
| | - Tsun-Jen Cheng
- Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan; Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan.
| |
Collapse
|
13
|
Carll AP, Crespo SM, Filho MS, Zati DH, Coull BA, Diaz EA, Raimundo RD, Jaeger TNG, Ricci-Vitor AL, Papapostolou V, Lawrence JE, Garner DM, Perry BS, Harkema JR, Godleski JJ. Inhaled ambient-level traffic-derived particulates decrease cardiac vagal influence and baroreflexes and increase arrhythmia in a rat model of metabolic syndrome. Part Fibre Toxicol 2017; 14:16. [PMID: 28545487 PMCID: PMC5445437 DOI: 10.1186/s12989-017-0196-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 05/15/2017] [Indexed: 11/24/2022] Open
Abstract
Background Epidemiological studies have linked exposures to ambient fine particulate matter (PM2.5) and traffic with autonomic nervous system imbalance (ANS) and cardiac pathophysiology, especially in individuals with preexisting disease. It is unclear whether metabolic syndrome (MetS) increases susceptibility to the effects of PM2.5. We hypothesized that exposure to traffic-derived primary and secondary organic aerosols (P + SOA) at ambient levels would cause autonomic and cardiovascular dysfunction in rats exhibiting features of MetS. Male Sprague Dawley (SD) rats were fed a high-fructose diet (HFrD) to induce MetS, and exposed to P + SOA (20.4 ± 0.9 μg/m3) for 12 days with time-matched comparison to filtered-air (FA) exposed MetS rats; normal diet (ND) SD rats were separately exposed to FA or P + SOA (56.3 ± 1.2 μg/m3). Results In MetS rats, P + SOA exposure decreased HRV, QTc, PR, and expiratory time overall (mean effect across the entirety of exposure), increased breathing rate overall, decreased baroreflex sensitivity (BRS) on three exposure days, and increased spontaneous atrioventricular (AV) block Mobitz Type II arrhythmia on exposure day 4 relative to FA-exposed animals receiving the same diet. Among ND rats, P + SOA decreased HRV only on day 1 and did not significantly alter BRS despite overall hypertensive responses relative to FA. Correlations between HRV, ECG, BRS, and breathing parameters suggested a role for autonomic imbalance in the pathophysiologic effects of P + SOA among MetS rats. Autonomic cardiovascular responses to P + SOA at ambient PM2.5 levels were pronounced among MetS rats and indicated blunted vagal influence over cardiovascular physiology. Conclusions Results support epidemiologic findings that MetS increases susceptibility to the adverse cardiac effects of ambient-level PM2.5, potentially through ANS imbalance. Electronic supplementary material The online version of this article (doi:10.1186/s12989-017-0196-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Alex P Carll
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA. .,Department of Physiology, Diabetes and Obesity Center, School of Medicine, University of Louisville, 580 South Preston Street, Delia Baxter Building, Room 404B, Louisville, KY, 40202, USA.
| | - Samir M Crespo
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Mauricio S Filho
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Douglas H Zati
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Brent A Coull
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Edgar A Diaz
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Rodrigo D Raimundo
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Faculty of Public Health, University of São Paulo, São Paulo, Brazil
| | - Thomas N G Jaeger
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Ana Laura Ricci-Vitor
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Federal University of São Paulo, São Paulo, Brazil
| | - Vasileios Papapostolou
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Joy E Lawrence
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - David M Garner
- Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK
| | - Brigham S Perry
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Jack R Harkema
- Department of Pathobiology, Michigan State University, East Lansing, MI, USA
| | - John J Godleski
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| |
Collapse
|
14
|
Stawski C, Nowack J, Körtner G, Geiser F. A new cue for torpor induction: charcoal, ash and smoke. J Exp Biol 2017; 220:220-226. [DOI: 10.1242/jeb.146548] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 10/20/2016] [Indexed: 12/13/2022]
Abstract
ABSTRACT
Recent work has shown that the use of torpor for energy conservation increases after forest fires in heterothermic mammals, probably in response to the reduction of food. However, the specific environmental cues for this increased torpor expression remain unknown. It is possible that smoke and the novel substrate of charcoal and ash act as signals for an impending period of starvation requiring torpor. We therefore tested the hypothesis that the combined cues of smoke, a charcoal/ash substrate and food shortage will enhance torpor expression in a small forest-dwelling marsupial, the yellow-footed antechinus (Antechinus flavipes), because like other animals that live in fire-prone habitats they must effectively respond to fires to ensure survival. Activity and body temperature patterns of individuals in outdoor aviaries were measured under natural environmental conditions. All individuals were strictly nocturnal, but diurnal activity was observed shortly after smoke exposure. Overall, torpor in females was longer and deeper than that in males. Interestingly, while both males and females increased daily torpor duration during food restriction by >2-fold as anticipated, a combination of food restriction and smoke exposure on a charcoal/ash substrate further increased daily torpor duration by ∼2-fold in both sexes. These data show that this combination of cues for torpor induction is stronger than food shortage on its own. Our study provides significant new information on how a small forest-dwelling mammal responds to fire cues during and immediately after a fire and identifies a new, not previously recognised, regulatory mechanism for thermal biology in mammals.
Collapse
Affiliation(s)
- Clare Stawski
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia
| | - Julia Nowack
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia
- Research Institute of Wildlife Ecology, Department of Integrative Biology and Evolution, University of Veterinary Medicine Vienna, Savoyenstrasse 1, Vienna 1160, Austria
| | - Gerhard Körtner
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia
| | - Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia
| |
Collapse
|
15
|
Yaniv Y, Ahmet I, Tsutsui K, Behar J, Moen JM, Okamoto Y, Guiriba T, Liu J, Bychkov R, Lakatta EG. Deterioration of autonomic neuronal receptor signaling and mechanisms intrinsic to heart pacemaker cells contribute to age-associated alterations in heart rate variability in vivo. Aging Cell 2016; 15:716-24. [PMID: 27168363 PMCID: PMC4933656 DOI: 10.1111/acel.12483] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2016] [Indexed: 12/19/2022] Open
Abstract
We aimed to determine how age‐associated changes in mechanisms extrinsic and intrinsic to pacemaker cells relate to basal beating interval variability (BIV) reduction in vivo. Beating intervals (BIs) were measured in aged (23–25 months) and adult (3–4 months) C57BL/6 male mice (i) via ECG in vivo during light anesthesia in the basal state, or in the presence of 0.5 mg mL−1 atropine + 1 mg mL−1 propranolol (in vivo intrinsic conditions), and (ii) via a surface electrogram, in intact isolated pacemaker tissue. BIV was quantified in both time and frequency domains using linear and nonlinear indices. Although the average basal BI did not significantly change with age under intrinsic conditions in vivo and in the intact isolated pacemaker tissue, the average BI was prolonged in advanced age. In vivo basal BIV indices were found to be reduced with age, but this reduction diminished in the intrinsic state. However, in pacemaker tissue BIV indices increased in advanced age vs. adults. In the isolated pacemaker tissue, the sensitivity of the average BI and BIV in response to autonomic receptor stimulation or activation of mechanisms intrinsic to pacemaker cells by broad‐spectrum phosphodiesterase inhibition declined in advanced age. Thus, changes in mechanisms intrinsic to pacemaker cells increase the average BIs and BIV in the mice of advanced age. Autonomic neural input to pacemaker tissue compensates for failure of molecular intrinsic mechanisms to preserve average BI. But this compensation reduces the BIV due to both the imbalance of autonomic neural input to the pacemaker cells and altered pacemaker cell responses to neural input.
Collapse
Affiliation(s)
- Yael Yaniv
- Biomedical Engineering Faculty Technion‐IIT Haifa Israel
| | - Ismayil Ahmet
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Kenta Tsutsui
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Joachim Behar
- Biomedical Engineering Faculty Technion‐IIT Haifa Israel
| | - Jack M. Moen
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Yosuke Okamoto
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Toni‐Rose Guiriba
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Jie Liu
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Rostislav Bychkov
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Edward G. Lakatta
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| |
Collapse
|
16
|
Abstract
The body responds to environmental stressors by triggering autonomic reflexes in the pulmonary receptors, baroreceptors, and chemoreceptors to maintain homeostasis. Numerous studies have shown that exposure to various gases and airborne particles can alter the functional outcome of these reflexes, particularly with respect to the cardiovascular system. Modulation of autonomic neural input to the heart and vasculature following direct activation of sensory nerves in the respiratory system, elicitation of oxidative stress and inflammation, or through other mechanisms is one of the primary ways that exposure to air pollution affects normal cardiovascular function. Any homeostatic process that utilizes the autonomic nervous system to regulate organ function might be affected. Thus, air pollution and other inhaled environmental irritants have the potential to alter both local airway function and baro- and chemoreflex responses, which modulate autonomic control of blood pressure and detect concentrations of key gases in the body. While each of these reflex pathways causes distinct responses, the systems are heavily integrated and communicate through overlapping regions of the brainstem to cause global effects. This short review summarizes the function of major pulmonary sensory receptors, baroreceptors, and carotid body chemoreceptors and discusses the impacts of air pollution exposure on these systems.
Collapse
|
17
|
Carll AP, Haykal-Coates N, Winsett DW, Hazari MS, Ledbetter AD, Richards JH, Cascio WE, Costa DL, Farraj AK. Cardiomyopathy confers susceptibility to particulate matter-induced oxidative stress, vagal dominance, arrhythmia and pulmonary inflammation in heart failure-prone rats. Inhal Toxicol 2015; 27:100-12. [PMID: 25600220 DOI: 10.3109/08958378.2014.995387] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Acute exposure to ambient fine particulate matter (PM2.5) is tied to cardiovascular morbidity and mortality, especially among those with prior cardiac injury. The mechanisms and pathophysiological events precipitating these outcomes remain poorly understood but may involve inflammation, oxidative stress, arrhythmia and autonomic nervous system imbalance. Cardiomyopathy results from cardiac injury, is the leading cause of heart failure, and can be induced in heart failure-prone rats through sub-chronic infusion of isoproterenol (ISO). To test whether cardiomyopathy confers susceptibility to inhaled PM2.5 and can elucidate potential mechanisms, we investigated the cardiophysiologic, ventilatory, inflammatory and oxidative effects of a single nose-only inhalation of a metal-rich PM2.5 (580 µg/m(3), 4 h) in ISO-pretreated (35 days × 1.0 mg/kg/day sc) rats. During the 5 days post-treatment, ISO-treated rats had decreased HR and BP and increased pre-ejection period (PEP, an inverse correlate of contractility) relative to saline-treated rats. Before inhalation exposure, ISO-pretreated rats had increased PR and ventricular repolarization time (QT) and heterogeneity (Tp-Te). Relative to clean air, PM2.5 further prolonged PR-interval and decreased systolic BP during inhalation exposure; increased tidal volume, expiratory time, heart rate variability (HRV) parameters of parasympathetic tone and atrioventricular block arrhythmias over the hours post-exposure; increased pulmonary neutrophils, macrophages and total antioxidant status one day post-exposure; and decreased pulmonary glutathione peroxidase 8 weeks after exposure, with all effects occurring exclusively in ISO-pretreated rats but not saline-pretreated rats. Ultimately, our findings indicate that cardiomyopathy confers susceptibility to the oxidative, inflammatory, ventilatory, autonomic and arrhythmogenic effects of acute PM2.5 inhalation.
Collapse
Affiliation(s)
- Alex P Carll
- Environmental Sciences and Engineering, University of North Carolina , Chapel Hill, NC , USA
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Zaky A, Bradley WE, Lazrak A, Zafar I, Doran S, Ahmad A, White CW, Dell'Italia LJ, Matalon S, Ahmad S. Chlorine inhalation-induced myocardial depression and failure. Physiol Rep 2015; 3:3/6/e12439. [PMID: 26109193 PMCID: PMC4510636 DOI: 10.14814/phy2.12439] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Victims of chlorine (Cl2) inhalation that die demonstrate significant cardiac pathology. However, a gap exists in the understanding of Cl2-induced cardiac dysfunction. This study was performed to characterize cardiac dysfunction occurring after Cl2 exposure in rats at concentrations mimicking accidental human exposures (in the range of 500 or 600 ppm for 30 min). Inhalation of 500 ppm Cl2 for 30 min resulted in increased lactate in the coronary sinus of the rats suggesting an increase in anaerobic metabolism by the heart. There was also an attenuation of myocardial contractile force in an ex vivo (Langendorff technique) retrograde perfused heart preparation. After 20 h of return to room air, Cl2 exposure at 500 ppm was associated with a reduction in systolic and diastolic blood pressure as well echocardiographic/Doppler evidence of significant left ventricular systolic and diastolic dysfunction. Cl2 exposure at 600 ppm (30 min) was associated with biventricular failure (observed at 2 h after exposure) and death. Cardiac mechanical dysfunction persisted despite increasing the inspired oxygen fraction concentration in Cl2-exposed rats (500 ppm) to ameliorate hypoxia that occurs after Cl2 inhalation. Similarly ex vivo cardiac mechanical dysfunction was reproduced by sole exposure to chloramine (a potential circulating Cl2 reactant product). These results suggest an independent and distinctive role of Cl2 (and its reactants) in inducing cardiac toxicity and potentially contributing to mortality.
Collapse
Affiliation(s)
- Ahmed Zaky
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama Department of Medicine, Birmingham Veteran Affairs Medical Center, Birmingham, Alabama Division of Cardiovascular Disease, University of Alabama Medical Center, Birmingham, Alabama
| | - Wayne E Bradley
- Department of Medicine, Birmingham Veteran Affairs Medical Center, Birmingham, Alabama Division of Cardiovascular Disease, University of Alabama Medical Center, Birmingham, Alabama
| | - Ahmed Lazrak
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Iram Zafar
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Stephen Doran
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Aftab Ahmad
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Carl W White
- Department of Pediatrics, University of Colorado Denver, Boulder, Colorado
| | - Louis J Dell'Italia
- Department of Medicine, Birmingham Veteran Affairs Medical Center, Birmingham, Alabama Division of Cardiovascular Disease, University of Alabama Medical Center, Birmingham, Alabama
| | - Sadis Matalon
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Shama Ahmad
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
19
|
Middlekauff HR, Park J, Moheimani RS. Adverse effects of cigarette and noncigarette smoke exposure on the autonomic nervous system: mechanisms and implications for cardiovascular risk. J Am Coll Cardiol 2015; 64:1740-50. [PMID: 25323263 DOI: 10.1016/j.jacc.2014.06.1201] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 06/24/2014] [Accepted: 06/30/2014] [Indexed: 11/27/2022]
Abstract
This review summarizes the detrimental effects of cigarette and noncigarette emission exposure on autonomic function, with particular emphasis on the mechanisms of acute and chronic modulation of the sympathetic nervous system. We propose that the nicotine and fine particulate matter in tobacco smoke lead to increased sympathetic nerve activity, which becomes persistent via a positive feedback loop between sympathetic nerve activity and reactive oxidative species. Furthermore, we propose that baroreflex suppression of sympathetic activation is attenuated in habitual smokers; that is, the baroreflex plays a permissive role, allowing sympathoexcitation to occur without restraint in the setting of increased pressor response. This model is also applicable to other nontobacco cigarette emission exposures (e.g., marijuana, waterpipes [hookahs], electronic cigarettes, and even air pollution). Fortunately, emerging data suggest that baroreflex sensitivity and autonomic function may be restored after smoking cessation, providing further evidence in support of the health benefits of smoking cessation.
Collapse
Affiliation(s)
- Holly R Middlekauff
- Division of Cardiology, Department of Medicine, University of California-Los Angeles, Los Angeles, California.
| | - Jeanie Park
- Renal Division, Department of Medicine, Emory University School of Medicine, and the Veterans Affairs Medical Center, Atlanta, Georgia
| | - Roya S Moheimani
- David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California
| |
Collapse
|
20
|
Carll AP, Hazari MS, Perez CM, Krantz QT, King CJ, Haykal-Coates N, Cascio WE, Costa DL, Farraj AK. An autonomic link between inhaled diesel exhaust and impaired cardiac performance: insight from treadmill and dobutamine challenges in heart failure-prone rats. Toxicol Sci 2013; 135:425-36. [PMID: 23872579 DOI: 10.1093/toxsci/kft155] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cardiac disease exacerbation is associated with short-term exposure to vehicular emissions. Diesel exhaust (DE) might impair cardiac performance in part through perturbing efferent sympathetic and parasympathetic autonomic nervous system (ANS) input to the heart. We hypothesized that acute changes in ANS balance mediate decreased cardiac performance upon DE inhalation. Young adult heart failure-prone rats were implanted with radiotelemeters to measure heart rate (HR), HR variability (HRV), blood pressure (BP), core body temperature, and pre-ejection period (PEP, a contractility index). Animals pretreated with sympathetic antagonist (atenolol), parasympathetic antagonist (atropine), or saline were exposed to DE (500 µg/m(3) fine particulate matter, 4h) or filtered air and then treadmill exercise challenged. At 1 day postexposure, separate rats were catheterized for left ventricular pressure (LVP), contractility, and lusitropy and assessed for autonomic influence using the sympathoagonist dobutamine and surgical vagotomy. During DE exposure, atenolol inhibited increases in HR, BP, and contractility, but not body temperature, suggesting a role for sympathetic dominance. During treadmill recovery at 4h post-DE exposure, HR and HRV indicated parasympathetic dominance in saline- and atenolol-pretreated groups that atropine inhibited. Conversely, at treadmill recovery 21h post-DE exposure, HRV and PEP indicated sympathetic dominance and subsequently diminished contractility that only atenolol inhibited. LVP at 1 day postexposure indicated that DE impaired contractility and lusitropy while abolishing parasympathetic-regulated cardiac responses to dobutamine. This is the first evidence that air pollutant inhalation both causes time-dependent oscillations between sympathetic and parasympathetic dominance and decreases cardiac performance via aberrant sympathetic dominance.
Collapse
Affiliation(s)
- Alex P Carll
- * Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Chuang HC, Hsueh TW, Chang CC, Hwang JS, Chuang KJ, Yan YH, Cheng TJ. Nickel-regulated heart rate variability: The roles of oxidative stress and inflammation. Toxicol Appl Pharmacol 2013; 266:298-306. [DOI: 10.1016/j.taap.2012.11.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 11/07/2012] [Accepted: 11/08/2012] [Indexed: 11/16/2022]
|
22
|
Galetin T, Tevoufouet EE, Sandmeyer J, Matthes J, Nguemo F, Hescheler J, Weiergräber M, Schneider T. Pharmacoresistant Cav 2·3 (E-type/R-type) voltage-gated calcium channels influence heart rate dynamics and may contribute to cardiac impulse conduction. Cell Biochem Funct 2012; 31:434-49. [PMID: 23086800 DOI: 10.1002/cbf.2918] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 09/21/2012] [Accepted: 09/24/2012] [Indexed: 11/10/2022]
Abstract
Voltage-gated Ca(2+) channels regulate cardiac automaticity, rhythmicity and excitation-contraction coupling. Whereas L-type (Cav 1·2, Cav 1·3) and T-type (Cav 3·1, Cav 3·2) channels are widely accepted for their functional relevance in the heart, the role of Cav 2·3 Ca(2+) channels expressing R-type currents remains to be elucidated. We have investigated heart rate dynamics in control and Cav 2·3-deficient mice using implantable electrocardiogram radiotelemetry and pharmacological injection experiments. Autonomic block revealed that the intrinsic heart rate does not differ between both genotypes. Systemic administration of isoproterenol resulted in a significant reduction in interbeat interval in both genotypes. It remained unaffected after administering propranolol in Cav 2·3(-|-) mice. Heart rate from isolated hearts as well as atrioventricular conduction for both genotypes differed significantly. Additionally, we identified and analysed the developmental expression of two splice variants, i.e. Cav 2·3c and Cav 2·3e. Using patch clamp technology, R-type currents could be detected in isolated prenatal cardiomyocytes and be related to R-type Ca(2+) channels. Our results indicate that on the systemic level, the pharmacologically inducible heart rate range and heart rate reserve are impaired in Cav 2·3 (-|-) mice. In addition, experiments on Langendorff perfused hearts elucidate differences in basic properties between both genotypes. Thus, Cav 2·3 does not only contribute to the cardiac autonomous nervous system but also to intrinsic rhythm propagation.
Collapse
Affiliation(s)
- Thomas Galetin
- Institute of Neurophysiology, University of Köln, Köln, Germany
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Ritz T. Airway responsiveness to psychological processes in asthma and health. Front Physiol 2012; 3:343. [PMID: 22973233 PMCID: PMC3433706 DOI: 10.3389/fphys.2012.00343] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 08/08/2012] [Indexed: 12/16/2022] Open
Abstract
Psychosocial factors have been found to impact airway pathophysiology in respiratory disease with considerable consistency. Influences on airway mechanics have been studied particularly well. The goal of this article is to review the literature on airway responses to psychological stimulation, discuss potential pathways of influence, and present a well-established emotion-induction paradigm to study airway obstruction elicited by unpleasant stimuli. Observational studies have found systematic associations between lung function and daily mood changes. The laboratory-based paradigm of bronchoconstrictive suggestion has been used successfully to elicit airway obstruction in a substantial proportion of asthmatic individuals. Other studies have demonstrated modulation of airway responses to standard airway challenges with exercise, allergens, or pharmacological agents by psychological factors. Standardized emotion-induction techniques have consistently shown airway constriction during unpleasant stimulation, with surgery, blood, and injury stimuli being particularly powerful. Findings with various forms of stress induction have been more mixed. A number of methodological factors may account for variability across studies, such as choice of measurement technique, temporal association between stimulation and measurement, and the specific quality and intensity of the stimulus material, in particular the extent of implied action-orientation. Research has also begun to elucidate physiological processes associated with psychologically induced airway responses, with vagal excitation and ventilatory influences being the most likely candidate pathways, whereas the role of specific central nervous system pathways and inflammatory processes has been less studied. The technique of emotion-induction using films has the potential to become a standardized challenge paradigm for the further exploration of airway hyperresponsiveness mediated by central nervous system processes.
Collapse
Affiliation(s)
- Thomas Ritz
- Southern Methodist University Dallas, TX, USA
| |
Collapse
|
24
|
Paigen B, Svenson KL, Von Smith R, Marion MA, Stearns T, Peters LL, Smith AL. Physiological effects of housing density on C57BL/6J mice over a 9-month period. J Anim Sci 2012; 90:5182-92. [PMID: 22952366 DOI: 10.2527/jas.2012-5417] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The NRC has consistently recommended floor space for animals used in science and agriculture. For mice, the recommended floor space is 77.4 cm(2) (12 in(2)) for a 15- to 25-g mouse. The NRC noted that its recommendations were based on "best professional judgment" and encouraged alternatives that were data driven. As part of a continual effort of The Jackson Laboratory to ensure the health and well-being of production and research mice, while promoting cost-effective, state-of-the-art research, several density-driven studies have been conducted by lab researchers. The objectives of this study were to determine the effect of housing density on variables related to mouse physiology and air quality in cages and assess the value of specific measured variables in such studies. In the present study, we monitored C57BL/6J mice in individually ventilated cages from weaning until 9 mo of age. Housing densities were equivalent to 66.4 or 36.8 cm(2) per mouse (10.3 or 5.7 in(2)). Clinical physiological variables representing general health and well-being were measured. Hematological traits, plasma lipids, and glucose, growth, bone mineral density, and percent body fat did not differ between housing densities. In the more densely housed mice, however, adrenal glands were significantly smaller, heart rates were significantly less, and food consumption was less. Cage air microenvironment was evaluated for ammonia, carbon dioxide, temperature, and humidity in cages changed weekly or every 2 wk. The cage microenvironment remained within acceptable limits at the higher density of mice at both cage-changing frequencies. The results suggest that mice housed for as long as 9 mo at up to twice the density currently recommended by NRC show no measurable adverse effects. Continued re-evaluation of the recommendation by measuring additional relevant variables of health and general well-being, and studying additional strains of mice is warranted.
Collapse
Affiliation(s)
- B Paigen
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Stapleton PA, Minarchick VC, McCawley M, Knuckles TL, Nurkiewicz TR. Xenobiotic particle exposure and microvascular endpoints: a call to arms. Microcirculation 2012; 19:126-42. [PMID: 21951337 DOI: 10.1111/j.1549-8719.2011.00137.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Xenobiotic particles can be considered in two genres: air pollution particulate matter and engineered nanoparticles. Particle exposures can occur in the greater environment, the workplace, and our homes. The majority of research in this field has, justifiably, focused on pulmonary reactions and outcomes. More recent investigations indicate that cardiovascular effects are capable of correlating with established mortality and morbidity epidemiological data following particle exposures. While the preliminary and general cardiovascular toxicology has been defined, the mechanisms behind these effects, specifically within the microcirculation, are largely unexplored. Therefore, the purpose of this review is several fold: first, a historical background on toxicological aspects of particle research is presented. Second, essential definitions, terminology, and techniques that may be unfamiliar to the microvascular scientist will be discussed. Third, the most current concepts and hypotheses driving cardiovascular research in this field will be reviewed. Lastly, potential future directions for the microvascular scientist will be suggested. Collectively speaking, microvascular research in the particle exposure field represents far more than a "niche." The immediate demand for basic, translational, and clinical studies is high and diverse. Microvascular scientists at all career stages are strongly encouraged to expand their research interests to include investigations associated with particle exposures.
Collapse
|
26
|
Jia X, Hao Y, Guo X. Ultrafine carbon black disturbs heart rate variability in mice. Toxicol Lett 2012; 211:274-80. [PMID: 22537739 DOI: 10.1016/j.toxlet.2012.04.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 04/05/2012] [Accepted: 04/06/2012] [Indexed: 10/28/2022]
Abstract
Previous epidemiological and toxicological studies have reported the associations between ambient particulate matter (PM) exposure and changes in heart rate variability (HRV), a marker of cardiac autonomic nervous system (ANS) function. However, both the responsible components in PM and their mechanisms affecting HRV remain uncertain. We propose that carbon black (CB), one of the main components in PM, may affect HRV through mechanisms independent of cardio-pulmonary and systemic inflammation and/or injury. Male C57BL/6 mice were exposed by intra-tracheal instillation to ultrafine CB (once every two days for three times) at doses of 0, 0.05, 0.15 and 0.6 mg/kg. HRV indices, standard deviation of all normal R-R intervals (SDNN) and the square root of mean of sum of squares of differences between adjacent normal R-R intervals (RMSSD), showed significant decreases in 0.15 and 0.6 mg/kg CB exposed groups. Slight pulmonary inflammation and myocardial injury were only observed in 0.6 mg/kg CB exposed group. We conclude that CB can disturb cardiac ANS function in mice, indicated by the withdrawal of parasympathetic modulation, through mechanisms independent of apparent myocardial and pulmonary injury.
Collapse
Affiliation(s)
- Xiaofeng Jia
- Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, Beijing, China
| | | | | |
Collapse
|
27
|
Amatullah H, North ML, Akhtar US, Rastogi N, Urch B, Silverman FS, Chow CW, Evans GJ, Scott JA. Comparative cardiopulmonary effects of size-fractionated airborne particulate matter. Inhal Toxicol 2012; 24:161-71. [PMID: 22356274 DOI: 10.3109/08958378.2011.650235] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONTEXT Strong epidemiological evidence exists linking particulate matter (PM) exposures with hospital admissions of individuals for cardiopulmonary symptoms. The PM size is important in influencing the extent of infiltration into the respiratory tract and systemic circulation and directs the differential physiological impacts. OBJECTIVE To investigate the differential effects of the quasi-ultrafine (PM(0.2)), fine (PM(0.15-2.5)), and coarse PM (PM(2.5-10)) size fractions on pulmonary and cardiac function. METHODS Female BALB/c mice were exposed to HEPA-filtered laboratory air or concentrated coarse, fine, or quasi-ultrafine PM using Harvard Ambient Particle Concentrators in conjunction with our nose-only exposure system. These exposures were conducted as part of the "Health Effects of Aerosols in Toronto (HEAT)" campaign. Following a 4 h exposure, mice underwent assessment of respiratory function and recording of electrocardiograms using the flexiVent® system. RESULTS Exposure to coarse and fine PM resulted in a significant reduction in quasistatic compliance of the lung. Baseline total respiratory resistance and maximum responsiveness to methacholine were augmented after coarse PM exposures but were not affected by quasi-ultrafine PM exposures. In contrast, quasi-ultrafine PM alone had a significant effect on heart rate and in reducing heart rate variability. CONCLUSION These findings indicate that coarse and fine PM influence lung function and airways responsiveness, while ultrafine PM can perturb cardiac function. This study supports the hypothesis that coarse and fine PM exerts its predominant physiologic effects at the site of deposition in the airways, whereas ultrafine PM likely crosses the alveolar epithelial barrier into the systemic circulation to affect cardiovascular function.
Collapse
Affiliation(s)
- Hajera Amatullah
- Division of Occupational and Environmental Health, Dalla Lana School of Public Health, University of Toronto, Ontario, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Park SK, Auchincloss AH, O'Neill MS, Prineas R, Correa JC, Keeler J, Barr RG, Kaufman JD, Diez Roux AV. Particulate air pollution, metabolic syndrome, and heart rate variability: the multi-ethnic study of atherosclerosis (MESA). ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:1406-11. [PMID: 20529761 PMCID: PMC2957920 DOI: 10.1289/ehp.0901778] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 06/08/2010] [Indexed: 05/20/2023]
Abstract
BACKGROUND Cardiac autonomic dysfunction has been suggested as a possible biologic pathway for the association between fine particulate matter ≤ 2.5 µm in diameter (PM2.5) and cardiovascular disease (CVD). We examined the associations of PM2.5 with heart rate variability, a marker of autonomic function, and whether metabolic syndrome (MetS) modified these associations. METHODS We used data from the Multi-Ethnic Study of Atherosclerosis to measure the standard deviation of normal-to-normal intervals (SDNN) and the root mean square of successive differences (rMSSD) of 5,465 participants 45-84 years old who were free of CVD at the baseline examination (2000-2002). Data from the U.S. regulatory monitor network were used to estimate ambient PM2.5 concentrations at the participants' residences. MetS was defined as having three or more of the following criteria: abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol, high blood pressure, and high fasting glucose. RESULTS After controlling for confounders, we found that an interquartile range (IQR) increase in 2-day average PM2.5 (10.2 µg/m3) was associated with a 2.1% decrease in rMSSD [95% confidence interval (CI), -4.2 to 0.0] and nonsignificantly associated with a 1.8% decrease in SDNN (95% CI, -3.7 to 0.1). Associations were stronger among individuals with MetS than among those without MetS: an IQR elevation in 2-day PM2.5 was associated with a 6.2% decrease in rMSSD (95% CI, -9.4 to -2.9) among participants with MetS, whereas almost no change was found among participants without MetS (p-interaction = 0.005). Similar effect modification was observed in SDNN (p-interaction = 0.011). CONCLUSION These findings suggest that autonomic dysfunction may be a mechanism through which PM exposure affects cardiovascular risk, especially among persons with MetS.
Collapse
Affiliation(s)
- Sung Kyun Park
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan 48109, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Rohr AC, Wagner JG, Morishita M, Kamal A, Keeler GJ, Harkema JR. Cardiopulmonary responses in spontaneously hypertensive and Wistar-Kyoto rats exposed to concentrated ambient particles from Detroit, Michigan. Inhal Toxicol 2010; 22:522-33. [PMID: 20384466 DOI: 10.3109/08958370903524509] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Toxicological effects have been observed in rats exposed to concentrated ambient particles (CAPs) from different regions of the United States. The objective of this study was to evaluate the cardiopulmonary and systemic effects of CAPs in Detroit. The authors stationed a mobile concentrator at a location near major traffic and industrial sources. Spontaneously hypertensive (SH) and Wistar-Kyoto (WKY) rats were exposed to fine CAPs (diameter < 0.1-2.5 microm) 8 h/day for 13 consecutive days. Animals were implanted with telemeters, and electrocardiogram data were recorded continuously. Bronchoalveolar lavage (BAL) fluid and plasma were analyzed. Comprehensive exposure monitoring was conducted, including CAPs components. CAPs exposure concentrations were 103-918 microg/m(3) (mean = 502 microg/m(3)). The authors found no statistically significant differences in heart rate or SDNN (standard deviation of the normal-to-normal intervals), a measure of heart rate variability, between CAPs-exposed and control rats. The authors found significantly higher levels of C-reactive protein in the serum of CAPs-exposed SH rats compared with air-exposed animals. Protein in BAL fluid was elevated in WKY rats exposed to CAPs. Measurement of trace metals in lung tissue showed elevated concentrations of V, Sb, La, and Ce in CAPs-exposed SH animals versus controls. These elements are generally associated with oil combustion, oil refining, waste incineration, and traffic. Examination of wind rose data from the exposure period confirmed that the predominant wind direction was SSW, the direction of many of the aforementioned sources. These results indicate that ambient particles in Detroit can cause mild pulmonary and systemic changes in rats, and suggest the importance of local PM(2.5) sources in these effects.
Collapse
Affiliation(s)
- Annette C Rohr
- Electric Power Research Institute, Palo Alto, California 94304, USA.
| | | | | | | | | | | |
Collapse
|