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Chan SMH, Brassington K, Almerdasi SA, Dobric A, De Luca SN, Coward‐Smith M, Wang H, Mou K, Akhtar A, Alateeq RA, Wang W, Seow HJ, Selemidis S, Bozinovski S, Vlahos R. Inhibition of oxidative stress by apocynin attenuated chronic obstructive pulmonary disease progression and vascular injury by cigarette smoke exposure. Br J Pharmacol 2023; 180:2018-2034. [PMID: 36908040 PMCID: PMC10953324 DOI: 10.1111/bph.16068] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/07/2023] [Accepted: 03/07/2023] [Indexed: 03/14/2023] Open
Abstract
BACKGROUND AND PURPOSE Cardiovascular disease affects up to half of the patients with chronic obstructive pulmonary disease (COPD), exerting deleterious impact on health outcomes and survivability. Vascular endothelial dysfunction marks the onset of cardiovascular disease. The present study examined the effect of a potent NADPH Oxidase (NOX) inhibitor and free-radical scavenger, apocynin, on COPD-related cardiovascular disease. EXPERIMENTAL APPROACH Male BALB/c mice were exposed to either room air (Sham) or cigarette smoke (CS) generated from 9 cigarettes·day-1 , 5 days a week for up to 24 weeks with or without apocynin treatment (5 mg·kg-1 ·day-1 , intraperitoneal injection). KEY RESULTS Eight-weeks of apocynin treatment reduced airway neutrophil infiltration (by 42%) and completely preserved endothelial function and endothelial nitric oxide synthase (eNOS) availability against the oxidative insults of cigarette smoke exposure. These preservative effects were maintained up until the 24-week time point. 24-week of apocynin treatment markedly reduced airway inflammation (reduced infiltration of macrophage, neutrophil and lymphocyte), lung function decline (hyperinflation) and prevented airway collagen deposition by cigarette smoke exposure. CONCLUSION AND IMPLICATIONS Limiting NOX activity may slow COPD progression and lower cardiovascular disease risk, particularly when signs of oxidative stress become evident.
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Affiliation(s)
- Stanley M. H. Chan
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Kurt Brassington
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Suleman Abdullah Almerdasi
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Aleksandar Dobric
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Simone N. De Luca
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Madison Coward‐Smith
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Hao Wang
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Kevin Mou
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Alina Akhtar
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Rana Abdullah Alateeq
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Wei Wang
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Huei Jiunn Seow
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Stavros Selemidis
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Steven Bozinovski
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
| | - Ross Vlahos
- Centre for Respiratory Science and Health, School of Health and Biomedical SciencesRMIT UniversityBundooraVictoria3083Australia
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Hahad O, Kuntic M, Kuntic I, Daiber A, Münzel T. Tobacco smoking and vascular biology and function: evidence from human studies. Pflugers Arch 2023:10.1007/s00424-023-02805-z. [PMID: 36961561 DOI: 10.1007/s00424-023-02805-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/02/2023] [Accepted: 03/11/2023] [Indexed: 03/25/2023]
Abstract
Tobacco cigarette smoking is among the most complex and least understood health risk factors. A deeper insight into the pathophysiological actions of smoking exposure is of special importance as smoking is a major cause of chronic non-communicable diseases, in particular of cardiovascular disease as well as risk factors such as atherosclerosis and arterial hypertension. It is well known that smoking exerts its negative effects on cardiovascular health through various interdependent pathophysiological actions including hemodynamic and autonomic alterations, oxidative stress, inflammation, endothelial dysfunction, thrombosis, and hyperlipidemia. Importantly, impaired vascular endothelial function is acknowledged as an early key event in the initiation and progression of smoking-induced atherosclerosis. Increasing evidence from human studies indicates that cigarette smoke exposure associates with a pathological state of the vascular endothelium mainly characterized by reduced vascular nitric oxide bioavailability due to increased vascular superoxide production. In the present overview, we provide compact evidence on the effects of tobacco cigarette smoke exposure on vascular biology and function in humans centered on main drivers of adverse cardiovascular effects including endothelial dysfunction, inflammation, and oxidative stress.
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Affiliation(s)
- Omar Hahad
- Department of Cardiology - Cardiology I, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany.
- German Center for Cardiovascular Research (DZHK), partner site Rhine-Main, Mainz, Germany.
| | - Marin Kuntic
- Department of Cardiology - Cardiology I, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany
| | - Ivana Kuntic
- Department of Cardiology - Cardiology I, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany
| | - Andreas Daiber
- Department of Cardiology - Cardiology I, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany
- German Center for Cardiovascular Research (DZHK), partner site Rhine-Main, Mainz, Germany
| | - Thomas Münzel
- Department of Cardiology - Cardiology I, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany
- German Center for Cardiovascular Research (DZHK), partner site Rhine-Main, Mainz, Germany
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Do individuals with autoimmune disease have increased risk of subclinical carotid atherosclerosis and stiffness? Hypertens Res 2021; 44:978-987. [PMID: 33833420 DOI: 10.1038/s41440-021-00655-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 03/02/2021] [Accepted: 03/14/2021] [Indexed: 12/13/2022]
Abstract
To explore the role of chronic inflammation inherent to autoimmune diseases in the development of subclinical atherosclerosis and arterial stiffness, this study recruited two population-based samples of individuals with and without autoimmune disease (ratio 1:5) matched by age, sex, and education level and with a longstanding (≥6 years) diagnosis of autoimmune disease. Common carotid intima-media thickness (IMT) and arterial distensibility and compliance were assessed with carotid ultrasound. Multivariable linear and logistic regression models were adjusted for 10-year cardiovascular risk. In total, 546 individuals with and without autoimmune diseases (91 and 455, respectively) were included. The mean age was 66 years (standard deviation 12), and 240 (43.9%) were women. Arterial stiffness did not differ according to the presence of autoimmune diseases. In men, the diagnosis of autoimmune diseases significantly increased common carotid IMT [beta-coefficient (95% confidence interval): 0.058 (0.009; 0.108); p value = 0.022] and the percentage with IMT ≥ 75th percentile [1.012 (0.145; 1.880); p value = 0.022]. Women without autoimmune disease were more likely to have IMT ≥ the 75th percentile [-2.181 (-4.214; -0.149); p value = 0.035], but the analysis of IMT as a continuous variable did not yield significant results. In conclusion, subclinical carotid atherosclerosis, but not arterial stiffness, was more common in men with autoimmune diseases. Women did not show significant differences in any of these carotid features. Sex was an effect modifier in the association between common carotid IMT values and the diagnosis of autoimmune diseases.
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Whitehead AK, Erwin AP, Yue X. Nicotine and vascular dysfunction. Acta Physiol (Oxf) 2021; 231:e13631. [PMID: 33595878 DOI: 10.1111/apha.13631] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 01/25/2021] [Accepted: 02/15/2021] [Indexed: 12/20/2022]
Abstract
Cigarette smoking is the single most important risk factor for the development of cardiovascular diseases (CVDs). However, the role of nicotine, the addictive component of all tobacco products, in the development of CVD is incompletely understood. Although increased public awareness of the harms of cigarette smoking has successfully led to a decline in its prevalence, the use of electronic cigarettes (e-cig) or electronic nicotine delivery system has increased dramatically in recent years because of the perception that these products are safe. This review summarizes our current knowledge of the expression and function of the nicotinic acetylcholine receptors in the cardiovascular system and the impact of nicotine exposure on cardiovascular health, with a focus on nicotine-induced vascular dysfunction. Nicotine alters vasoreactivity through endothelium-dependent and/or endothelium-independent mechanisms, leading to clinical manifestations in both cigarette smokers and e-cig users. In addition, nicotine induces vascular remodelling through its effects on proliferation, migration and matrix production of both vascular endothelial and vascular smooth muscle cells. The purpose of this review is to identify critical knowledge gaps regarding the effects of nicotine on the vasculature and to stimulate continued nicotine research.
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Affiliation(s)
- Anna K. Whitehead
- Department of Physiology Louisiana State University Health Sciences Center New Orleans LA USA
| | - Abigail P. Erwin
- Department of Physiology Louisiana State University Health Sciences Center New Orleans LA USA
| | - Xinping Yue
- Department of Physiology Louisiana State University Health Sciences Center New Orleans LA USA
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Mobarrez F, Antoniewicz L, Hedman L, Bosson JA, Lundbäck M. Electronic cigarettes containing nicotine increase endothelial and platelet derived extracellular vesicles in healthy volunteers. Atherosclerosis 2020; 301:93-100. [PMID: 32122618 DOI: 10.1016/j.atherosclerosis.2020.02.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 02/04/2020] [Accepted: 02/12/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND AIMS E-cigarette use is increasingly common. Whether e-cigarettes are harmful to human health is an intensely debated subject. In order to investigate whether e-cigarettes with and without nicotine cause different vascular responses, we obtained blood samples from healthy young volunteers who performed brief active e-cigarette inhalations. Extracellular vesicles (EVs) of endothelial and platelet origin were measured to determine vascular changes. METHODS Using a randomized, double-blind, crossover design, 17 healthy occasional smokers inhaled 30 puffs of e-cigarette vapor during 30 min. Blood samples were collected at baseline, as well as at 0, 2, 4 and 6 h post-exposure. EVs from platelets and endothelial cells were measured by flow cytometry. RESULTS Platelet and endothelial derived EVs were significantly increased with peak levels seen at 4 h following exposure to active inhalation of e-cigarette vapor with nicotine. Moreover, platelet derived EVs, expressing platelet activation marker P-selectin and the inflammation marker, CD40 ligand, were also significantly increased following inhalation of e-cigarette vapor with nicotine. In addition, platelet derived EVs expressing CD40 ligand was increased after inhalation of e-cigarette vapor without nicotine. CONCLUSION As few as 30 puffs of nicotine-containing e-cigarette vapor caused an increase in levels of circulating EVs of endothelial and platelet origin, which may signify underlying vascular changes. Although e-cigarette vapor without nicotine caused an increase in platelet EVs expressing CD40 ligand, nicotine, as a component in the vapor, seems to have a more compelling effect on extracellular vesicle formation and protein composition.
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Affiliation(s)
- Fariborz Mobarrez
- Department of Medical Sciences, Uppsala University, 75185, Uppsala, Sweden
| | - Lukasz Antoniewicz
- Karolinska Institutet, Department of Clinical Sciences, Division of Internal Medicine, Danderyd University Hospital, Stockholm, Sweden
| | - Linnea Hedman
- Umeå University, Department of Public Health and Clinical Medicine, Section of Sustainable Health, The OLIN Unit, Umeå, Sweden
| | - Jenny A Bosson
- Umeå University, Department of Public Health and Clinical Medicine, Division of Medicine/Respiratory Medicine, Umeå, Sweden
| | - Magnus Lundbäck
- Karolinska Institutet, Department of Clinical Sciences, Division of Cardiovascular Medicine, Danderyd University Hospital, Stockholm, Sweden.
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Abstract
OBJECTIVE As endothelial dysfunction is an early event in atherosclerosis formation, we investigated if proteins previously related to cardiovascular disease also were related to endothelial function using a novel targeted proteomics approach. METHODS In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (n = 850-970, all aged 70 years), endothelium-dependent vasodilation (EDV) in the forearm was assessed by intra-arterial infusion of acetylcholine. Flow-mediated vasodilation (FMD) was investigated in the brachial artery by ultrasound. The same investigations were carried out in the Prospective investigation of Obesity, Energy and Metabolism (POEM) study (n = 375-461, all aged 50 years). After strict quality control, 84 cardiovascular-related proteins measured by the proximity extension assay were studied in relation to EDV and FMD in PIVUS (discovery sample) and POEM (validation sample). RESULTS Of the 15 proteins being significantly related to EDV in PIVUS (false discovery rate <0.025), seven could be replicated in POEM at nominal significance and same effect direction when adjusted for sex and storage time. Of those, only cathepsin D remained significant following further adjustment for traditional cardiovascular risk factors (beta, -0.08; 95% confidence interval, -0.16, -0.01; P = 0.033; change in ln-transformed EDV per 1-SD increase in protein level). No protein was significantly related to FMD. CONCLUSION Using a discovery/validation approach in two samples, our results indicate an inverse association between plasma cathepsin D levels and endothelial-dependent vasodilation.
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Li C, Sun H, Xu G, McCarter KD, Li J, Mayhan WG. Mito-Tempo prevents nicotine-induced exacerbation of ischemic brain damage. J Appl Physiol (1985) 2018; 125:49-57. [PMID: 29420160 DOI: 10.1152/japplphysiol.01084.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Nicotine may contribute to the pathogenesis of cerebrovascular disease via the generation of reactive oxygen species (ROS). Overproduction of ROS leads to brain damage by intensifying postischemic inflammation. Our goal was to determine the effect of Mito-Tempo, a mitochondria-targeted antioxidant, on ischemic brain damage and postischemic inflammation during chronic exposure to nicotine. Male Sprague-Dawley rats were divided into four groups: control, nicotine, Mito-Tempo-treated control, and Mito-Tempo-treated nicotine. Nicotine (2 mg·kg-1·day-1) was administered via an osmotic minipump for 4 wk. Mito-Tempo (0.7 mg·kg-1·day-1 ip) was given for 7 days before cerebral ischemia. Transient focal cerebral ischemia was induced by occlusion of the middle cerebral artery for 2 h. Brain damage and inflammation were evaluated after 24 h of reperfusion by measuring infarct volume, expression of adhesion molecules, activity of matrix metalloproteinase, brain edema, microglial activation, and neutrophil infiltration. Nicotine exacerbated infarct volume and worsened neurological deficits. Nicotine did not alter baseline ICAM-1 expression, matrix metallopeptidase-2 activity, microglia activation, or neutrophil infiltration but increased these parameters after cerebral ischemia. Mito-Tempo did not have an effect in control rats but prevented the chronic nicotine-induced augmentation of ischemic brain damage and postischemic inflammation. We suggest that nicotine increases brain damage following cerebral ischemia via an increase in mitochondrial oxidative stress, which, in turn, contributes to postischemic inflammation. NEW & NOTEWORTHY Our findings have important implications for the understanding of mechanisms contributing to increased susceptibility of the brain to damage in smokers and users of nicotine-containing tobacco products.
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Affiliation(s)
- Chun Li
- Department of Cellular Biology and Anatomy, Center for Cardiovascular Diseases and Sciences, Louisiana State University Health Sciences Center-Shreveport , Shreveport, Louisiana
| | - Hong Sun
- Department of Cellular Biology and Anatomy, Center for Cardiovascular Diseases and Sciences, Louisiana State University Health Sciences Center-Shreveport , Shreveport, Louisiana
| | - Guodong Xu
- Department of Cellular Biology and Anatomy, Center for Cardiovascular Diseases and Sciences, Louisiana State University Health Sciences Center-Shreveport , Shreveport, Louisiana.,Department of Neurology, Hebei General Hospital , Shijiazhuang, Hebei , China
| | - Kimberly D McCarter
- Department of Cellular Biology and Anatomy, Center for Cardiovascular Diseases and Sciences, Louisiana State University Health Sciences Center-Shreveport , Shreveport, Louisiana
| | - Jiyu Li
- Department of Cellular Biology and Anatomy, Center for Cardiovascular Diseases and Sciences, Louisiana State University Health Sciences Center-Shreveport , Shreveport, Louisiana
| | - William G Mayhan
- Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South Dakota, Vermillion, South Dakota
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Taylor BA, Zaleski AL, Dornelas EA, Thompson PD. The impact of tetrahydrobiopterin administration on endothelial function before and after smoking cessation in chronic smokers. Hypertens Res 2016; 39:144-50. [PMID: 26606877 DOI: 10.1038/hr.2015.130] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 10/22/2015] [Accepted: 10/27/2015] [Indexed: 12/28/2022]
Abstract
Cardiovascular disease mortality is reduced following smoking cessation but the reversibility of specific atherogenic risk factors such as endothelial dysfunction is less established. We assessed brachial artery flow-mediated dilation (FMD) in 57 chronic smokers and 15 healthy controls, alone and after oral tetrahydrobiopterin (BH4) administration, to assess the extent to which reduced bioactivity of BH4, a cofactor for the endothelial nitric oxide synthase enzyme (eNOS), contributes to smoking-associated reductions in FMD. Thirty-four smokers then ceased cigarette and nicotine use for 1 week, after which FMD (±BH4 administration) was repeated. Brachial artery FMD was calculated as the peak dilatory response observed relative to baseline (%FMD). Endothelium-independent dilation was assessed by measuring the dilatory response to sublingual nitroglycerin (%NTG). Chronic smokers exhibited reduced %FMD relative to controls: (5.6±3.0% vs. 8.1±3.7%; P<0.01) and %NTG was not different between groups (P=0.22). BH4 administration improved FMD in both groups (P=0.03) independent of smoking status (P=0.78) such that FMD was still lower in smokers relative to controls (6.6±3.3% vs. 9.8±3.2%; P<0.01). With smoking cessation, FMD increased significantly (from 5.0±2.9 to 7.8±3.2%;P<0.01); %NTG was not different (P=0.57) and BH4 administration did not further improve FMD (P=0.33). These findings suggest that the blunted FMD observed in chronic smokers, likely due at least in part to reduced BH4 bioactivity and eNOS uncoupling, can be restored with smoking cessation. Post-cessation BH4 administration does not further improve endothelial function in chronic smokers, unlike the effect observed in nonsmokers, indicating a longer-term impact of chronic smoking on vascular function that is not acutely reversible.
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Affiliation(s)
- Beth A Taylor
- Division of Cardiology, Henry Low Heart Center, Hartford Hospital, Hartford, CT, USA
- Department of Kinesiology, University of Connecticut, Storrs, CT, USA
- University of Connecticut School of Medicine, Farmington, CT, USA
| | - Amanda L Zaleski
- Division of Cardiology, Henry Low Heart Center, Hartford Hospital, Hartford, CT, USA
- Department of Kinesiology, University of Connecticut, Storrs, CT, USA
| | - Ellen A Dornelas
- Division of Cardiology, Henry Low Heart Center, Hartford Hospital, Hartford, CT, USA
- University of Connecticut School of Medicine, Farmington, CT, USA
| | - Paul D Thompson
- Division of Cardiology, Henry Low Heart Center, Hartford Hospital, Hartford, CT, USA
- University of Connecticut School of Medicine, Farmington, CT, USA
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Farag MM, Selima EA, Salama MA. Impact of chronic nicotine administration on bone mineral content in young and adult rats: A comparative study. Eur J Pharmacol 2013; 720:1-6. [DOI: 10.1016/j.ejphar.2013.10.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 10/30/2013] [Accepted: 10/31/2013] [Indexed: 10/26/2022]
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Altintas MA, Altintas AA, Guggenheim M, Gohritz A, Meyer-Marcotty M, Vogt PM. Reflectance confocal-laser-scanning microscopy in vivo assessments of cigarette-induced dynamic alterations of cutaneous microcirculation on histomorphological level. Microsc Res Tech 2009; 72:347-50. [DOI: 10.1002/jemt.20661] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Mayhan WG, Arrick DM, Sharpe GM, Sun H. Nitric oxide synthase-dependent responses of the basilar artery during acute infusion of nicotine. Nicotine Tob Res 2009; 11:270-7. [PMID: 19246430 DOI: 10.1093/ntr/ntn025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Our goals were to determine whether acute exposure to nicotine alters nitric oxide synthase (NOS)-dependent responses of the basilar artery and to identify a potential role for activation of NAD(P)H oxidase in nicotine-induced impairment in NOS-dependent responses of the basilar artery. METHODS We measured in vivo diameter of the basilar artery in response to NOS-dependent (acetylcholine) and NOS-independent (nitroglycerin) agonists before and during an acute infusion of nicotine (2 microg/kg/min intravenously for 30 min followed by a maintenance dose of 0.35 microg/kg/min). In addition, we measured superoxide anion production (lucigenin chemiluminescence) by the basilar artery in response to nicotine in the absence or presence of apocynin. RESULTS We found that NOS-dependent, but not NOS-independent, vasodilation was impaired during infusion of nicotine. In addition, treatment of the basilar artery with apocynin (100 microM, 30 min prior to infusion of nicotine) prevented nicotine-induced impairment in NOS-dependent vasodilation. Further, the production of superoxide anion was increased in the basilar artery by nicotine, and this increase could be inhibited by apocynin. DISCUSSION Our findings suggest that acute exposure to nicotine impairs NOS-dependent dilation of the basilar artery by a mechanism that appears to be related to the release of superoxide anion. A possible source of superoxide may be via the activation of NAD(P)H oxidase.
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Affiliation(s)
- William G Mayhan
- Department of Cellular and Integrative Physiology, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA.
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Mavropoulos A, Brodin P, Rösing CK, Aass AM, Aars H. Gingival blood flow in periodontitis patients before and after periodontal surgery assessed in smokers and non-smokers. J Periodontol 2007; 78:1774-82. [PMID: 17760548 DOI: 10.1902/jop.2007.060472] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The aim of this study was to evaluate the gingival blood flow of smokers and non-smokers with periodontal disease before and after surgical periodontal treatment. METHODS Nine smokers and six non-smokers with at least two periodontal lesions were included in the study. Laser Doppler flowmetry was used to measure blood flow in two gingival sites and two skin sites. Two intrabony defects were treated surgically at the same time; enamel matrix derivative was applied at random to one of the sites, whereas the other site received a placebo gel. We measured resting gingival blood flow (GBF) and responses to cold pressor test (CPT) and to smoking and made continuous measurements of blood pressure (BP). Resting GBF levels of 26 young healthy subjects were used as a reference value. RESULTS Resting GBF was significantly lower for the periodontitis patients compared to the reference subjects, regardless of smoking habits. GBF and gingival vascular conductance (VC) decreased significantly pre- and postoperatively in response to smoking. CPT evoked significant decreases in VC in smokers and non-smokers. Skin blood flow decreased significantly in response to CPT, more so in the non-smokers. BP was significantly higher in the non-smokers. CONCLUSIONS Resting GBF of periodontitis patients was not lower in smokers than in non-smokers, but it was significantly lower than in the younger reference subjects. In contrast to our earlier findings in healthy subjects, smoking one cigarette may cause a decrease in GBF and VC in periodontitis patients. These observations suggested the existence of a dysfunction in the gingival vasculature in smokers and non-smokers with periodontitis.
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Affiliation(s)
- Antonios Mavropoulos
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway.
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Arrick DM, Mayhan WG. Acute infusion of nicotine impairs nNOS-dependent reactivity of cerebral arterioles via an increase in oxidative stress. J Appl Physiol (1985) 2007; 103:2062-7. [PMID: 17901243 DOI: 10.1152/japplphysiol.00411.2007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our goals were to determine whether acute exposure to nicotine alters neuronal nitric oxide synthase (nNOS)-dependent reactivity of cerebral arterioles and to identify a potential role for oxidative stress in nicotine-induced impairment in nNOS-dependent responses of cerebral arterioles. We measured in vivo diameter of cerebral arterioles to nNOS-dependent (N-methyl-d-aspartate and kainate) and -independent (nitroglycerin) agonists before and during acute treatment with nicotine. We found that nNOS-dependent, but not -independent, vasodilatation was impaired during treatment with nicotine. In addition, treatment of the cerebral microcirculation with tempol (1 h before infusion of nicotine) prevented nicotine-induced impairment in nNOS-dependent vasodilatation. Furthermore, the production of superoxide anion (lucigenin chemiluminescence) was increased in parietal cortex tissue of rats by treatment with nicotine, and this increase in superoxide anion production could be inhibited by tempol. Our findings suggest that acute exposure to nicotine impairs nNOS-dependent dilatation of cerebral arterioles by a mechanism that appears to be related to the formation of superoxide anion.
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Affiliation(s)
- Denise M Arrick
- Department of Cellular and Integrative Physiology, Omaha, NE 68198-5850, USA
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Siafaka A, Angelopoulos E, Kritikos K, Poriazi M, Basios N, Gerovasili V, Andreou A, Roussos C, Nanas S. Acute Effects of Smoking on Skeletal Muscle Microcirculation Monitored by Near-Infrared Spectroscopy. Chest 2007; 131:1479-85. [PMID: 17494797 DOI: 10.1378/chest.06-2017] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Cigarette smoking predisposes to vascular disease. Our study aimed to assess the acute effects of cigarette smoking on peripheral microcirculation using near-infrared spectroscopy (NIRS) and to compare microcirculatory function of smokers with that of nonsmokers. METHODS We examined 65 healthy volunteers: 25 smokers (14 men and 11 women; age range, 20 to 27 years) and 40 nonsmokers (31 men and 9 women; age range, 19 to 38 years). Smokers had refrained from smoking for 2 h prior to the examination. Tissue O(2) saturation (Sto(2)), defined as the percentage of hemoglobin saturation in the microvasculature compartments, was measured with a probe placed on the thenar muscle. Sto(2) baseline values were recorded for 5 min. Subsequently, the brachial artery occlusion technique was applied to evaluate microcirculatory function before, during, and after smoking one cigarette. RESULTS Sto(2) before smoking was 85 +/- 6% (mean +/- SD), not differing significantly between men and women (84.4 +/- 6.6% vs 85.6 +/- 5.8%, respectively; p = 0.721). Sto(2) did not change significantly during smoking. O(2) consumption rate was significantly greater in women (33.4 +/- 6.7 Sto(2) U/min vs 25.7 +/- 7.1 Sto(2) U/min, p = 0.032) at baseline and throughout the smoking session. O(2) consumption rate was reduced during smoking (p < 0.001) and at 5 min after the smoking session. Smoking had a significant effect on vascular reactivity (p = 0.015), with no significant differences between genders. Five minutes after smoking, vascular reactivity had returned to approximately normal levels. CONCLUSION Smoking acutely affects microcirculatory function. NIRS is a noninvasive, operator-independent technique that can document these effects. It seems promising for the prospective evaluation of the effects of long-term exposure to cigarette smoke.
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Affiliation(s)
- Angeliki Siafaka
- First Critical Care Department, Evangelismos Hospital, National and Kapodistrian University of Athens, Athens, Greece
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Suter LG, Murabito JM, Felson DT, Fraenkel L. Smoking, alcohol consumption, and Raynaud's phenomenon in middle age. Am J Med 2007; 120:264-71. [PMID: 17349450 DOI: 10.1016/j.amjmed.2006.06.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2006] [Revised: 05/24/2006] [Accepted: 06/01/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND Data suggest Raynaud's phenomenon shares risk factors with cardiovascular disease. Studies of smoking, alcohol consumption, and Raynaud's have produced conflicting results and were limited by small sample size and failure to adjust for confounders. Our objective was to determine whether smoking and alcohol are independently associated with Raynaud's in a large, community-based cohort. METHODS By using a validated survey to classify Raynaud's in the Framingham Heart Study Offspring Cohort, we performed sex-specific analyses of Raynaud's status by smoking and alcohol consumption in 1840 women and 1602 men. Multivariable logistic regression analyses were used to examine the relationship of Raynaud's to smoking and alcohol consumption. RESULTS Current smoking was not associated with Raynaud's in women but was associated with increased risk in men (adjusted odds ratio [OR] 2.59, 95% confidence interval [CI], 1.11-6.04). Heavy alcohol consumption in women was associated with increased risk of Raynaud's (adjusted OR 1.69, 95% CI, 1.02-2.82), whereas moderate alcohol consumption in men was associated with reduced risk (adjusted OR 0.51, 95% CI, 0.29-0.89). In both genders, red wine consumption was associated with a reduced risk of Raynaud's (adjusted OR 0.59, 95% CI, 0.36-0.96 in women and adjusted OR 0.30, 95% CI, 0.15-0.62 in men). CONCLUSIONS Our data suggest that middle-aged women and men may have distinct physiologic mechanisms underlying their Raynaud's, and thus sex-specific therapeutic approaches may be appropriate. Our data also support the possibility that moderate red wine consumption may protect against Raynaud's.
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Affiliation(s)
- Lisa G Suter
- VA Connecticut Healthcare System, West Haven, Conn, USA.
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Fang Q, Sun H, Arrick DM, Mayhan WG. Inhibition of NADPH oxidase improves impaired reactivity of pial arterioles during chronic exposure to nicotine. J Appl Physiol (1985) 2005; 100:631-6. [PMID: 16210431 DOI: 10.1152/japplphysiol.00975.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our goals were to determine whether chronic exposure to nicotine alters nitric oxide synthase (NOS)-dependent reactivity of cerebral (pial) arterioles and to identify a potential role for NADPH oxidase in impaired NOS-dependent responses during chronic exposure to nicotine. We measured in vivo diameter of pial arterioles to NOS-dependent (acetylcholine and ADP) and -independent (nitroglycerin) agonists in saline-treated rats and rats chronically treated with nicotine (2 mg.kg(-1).day(-1) for 2 wk via an osmotic minipump). We found that NOS-dependent, but not -independent, vasodilatation was impaired in nicotine-treated compared with saline-treated rats. In addition, the production of superoxide anion (lucigenin chemiluminescence) was increased in rats treated with nicotine compared with saline-treated rats. Furthermore, using Western blot analysis, we found that chronic exposure to nicotine increased p47phox protein in the parietal cortex. Finally, we found that apocynin (40 mg.kg(-1).day(-1)) in the drinking water to inhibit NADPH oxidase alleviated impaired NOS-dependent cerebral vasodilatation in nicotine treated rats but did not alter NOS-dependent responses in saline treated rats and did not alter NOS-independent reactivity in saline- or nicotine-treated rats. These findings suggest that chronic exposure to nicotine impairs NOS-dependent dilatation of pial arterioles by a mechanism that appears to be related to the formation of superoxide anion via activation of NADPH oxidase.
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Affiliation(s)
- Qin Fang
- Dept. of Cellular and Integrative Physiology, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
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18
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Garcíia‐Fernández R, Pérez‐Velasco JG, Concepcion‐Milian A, Sosa S, Navaroli F, García‐Barreto D. Estrogen does not prevent endothelial dysfunction caused by cigarette smoking. Clin Cardiol 2004; 27:71-3. [PMID: 14979623 PMCID: PMC6653942 DOI: 10.1002/clc.4960270205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Estrogen favors endothelial function while acute tobacco use provokes dysfunction. Previous studies have not examined the effect of smoking one cigarette at different stages of the menstrual cycle. HYPOTHESIS Favorable actions of estrogen on endothelial function are transitorily abolished by smoking one cigarette. METHODS Brachial artery endothelium-dependent dilation was measured noninvasively before, 10 min, and 1 h after smoking in 17 healthy premenopausal women. Studies were done in the first 3 days (early stage) and repeated between Days 9 and 13 of the menstrual cycle (middle stage). Estradiol was measured after each study. RESULTS At basal conditions, women in the middle stage of their cycles, when estradiol was 20 times higher than in the early stage, had significantly more endothelial-dependent brachial dilatation. No difference in the marked depression caused by cigarette smoking was found between the two stages. One h recuperation was complete in both phases. CONCLUSION Cigarette smoking abolishes the protection of circulating estrogen on endothelial function.
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Affiliation(s)
| | | | | | - Sualy Sosa
- Institute of Cardiology and Cardiovascular Surgery, Havana, Cuba
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Warner DO, Joyner MJ, Charkoudian N. Nicotine increases initial blood flow responses to local heating of human non-glabrous skin. J Physiol 2004; 559:975-84. [PMID: 15272048 PMCID: PMC1665171 DOI: 10.1113/jphysiol.2004.062943] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nicotine affects the regulation of skin blood flow (SkBF), but the mechanisms involved are not well understood. We tested the hypothesis that acute exposure to nicotine inhibits both the initial neurally mediated component and the later sustained component of SkBF responses to local heating of non-glabrous skin in humans. SkBF (measured by laser-Doppler) responses to local heating of forearm skin from 32 to 42 degrees C were measured in 11 chronic smokers. Heating occurred at one site over 15 min (RAMP) and over 90 s (STEP) at another site, and was maintained for an additional 30 min. STEP heating was also applied to a site pretreated with bretylium via iontophoresis to inhibit noradrenergic neurotransmission. Responses were measured before and after acute administration of nicotine via cigarettes or nasal spray in two experimental sessions. Nicotine decreased resting skin blood flow (P < 0.05); this response was inhibited by bretylium. During RAMP, nicotine increased the initial SkBF at 42 degrees C (by approximately 12%, P < 0.05). For STEP, nicotine increased the initial peak response (by approximately 25%, P < 0.05), and decreased the sustained plateau value (by approximately 10%, P < 0.05). In skin pretreated with bretylium, the increase caused by nicotine in the initial peak value persisted, but the plateau value was not different from pre-nicotine. These data suggest that in abstinent cigarette smokers, nicotine augments initial responses to both gradual and rapid non-painful heating of non-glabrous skin by sensitizing the sensory nerves that mediate the axon reflex associated with rapid vasodilatation. In contrast, nicotine decreases SkBF responses to prolonged heating by activating noradrenergic nerves.
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Affiliation(s)
- David O Warner
- Department of Anaesthesiology, Mayo Clinic College of Medicine, Rochester, MN, USA.
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20
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Granberry MC, Smith ES, Troillett RD, Eidt JF. Forearm endothelial response in smokeless tobacco users compared with cigarette smokers and nonusers of tobacco. Pharmacotherapy 2003; 23:974-8. [PMID: 12921243 DOI: 10.1592/phco.23.8.974.32871] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
STUDY OBJECTIVE To compare brachial artery flow-mediated dilation (FMD) in subjects who use smokeless tobacco, smoke cigarettes, or do not use any tobacco product. DESIGN Cross-sectional study. SETTING University-affiliated outpatient clinic. SUBJECTS Seventeen apparently healthy volunteers who for more than 1 year smoked at least 10 cigarettes/day, used at least two containers of smokeless tobacco/week, or did not use any tobacco product. MEASUREMENTS AND MAIN RESULTS Baseline characteristics of subjects were similar among the three groups except for mean age and serum cotinine level. Baseline brachial artery diameter, endothelium-dependent FMD induced by reactive hyperemia, and endothelium-independent dilation induced by administration of sublingual nitroglycerin were measured. Mean FMD over baseline was 4.1% +/- 0.7% in subjects who used smokeless tobacco, 3.9% +/- 5.1% in cigarettes smokers, and 12.2% +/- 5.7% in nonusers of tobacco (p=0.01). Endothelium-independent dilation induced by nitroglycerin was not statistically different among the three groups. CONCLUSION Brachial artery FMD, a surrogate for endothelial dysfunction, was significantly impaired in smokeless tobacco users and cigarette smokers compared with nonusers of tobacco.
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Affiliation(s)
- Mark C Granberry
- Cooperative Pharmacy Program, College of Health Sciences and Human Services, University of Texas-Pan American, Edinburg, Texas 78539, USA
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Affiliation(s)
- Neal L Benowitz
- Division of Clinical Pharmacology and Experimental Therapeutics, University of California, San Francisco, CA 94143-1220, USA.
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22
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Feitelson JBA, Rowell PP, Roberts CS, Fleming JT. Two week nicotine treatment selectively increases bone vascular constriction in response to norepinephrine. J Orthop Res 2003; 21:497-502. [PMID: 12706023 DOI: 10.1016/s0736-0266(02)00235-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This study was designed to determine if nicotine treatment alters the constrictor and/or dilator function of the vessels which regulate blood flow to intact bone. Nicotine (1.7 mg/kg/day) or nicotine-free, phosphate-buffered saline was administered subcutaneously to mature male rats for 2 weeks via osmotic mini-pumps. On the 14th day, the rats were anesthetized and in vivo experiments were performed to quantitate the changes in arterial blood pressure and perfusion of the intact tibia (measured by laser Doppler flowmetry) in response to two constrictor agonists (norepinephrine, NE and arginine vasopressin, AVP) and two vasodilator agents (acetylcholine, ACh and sodium nitroprusside, SNP). Dose-response curves were generated by plotting the change in the bone vascular resistance index (mmHg/bone perfusion units) evoked by each dose of agonist. In addition, bone arteriolar expression of endothelial nitric oxide synthase protein was quantitated by Western blot analysis. Nicotine treatment significantly enhanced the constriction of the bone vasculature in response to NE, but not to AVP. Vascular dilation in response to ACh and SNP was not changed by nicotine. These results indicate that nicotine selectively accentuates the constrictor response of the bone vasculature to exogenous NE. This enhanced constriction to NE is not due to impaired endothelial cell release of nitric oxide or diminished smooth muscle response to nitric oxide. Since NE and AVP activate similar cell signaling mechanisms to induce constriction, the selective enhancement of NE-induced constriction suggests that nicotine alters a mechanism unique to NE signaling; possibly the number or binding affinity of alpha adrenergic receptors. Since endogenous NE regulates basal blood flow to bone, the effect of nicotine to augment NE-induced constriction could lead to a chronic reduction in blood flow to bone.
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Affiliation(s)
- J B A Feitelson
- Department of Physiology and Biophysics, 1115A, Health Sciences Center, University of Louisville, KY 40292, USA
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Steer P, Vessby B, Lind L. Endothelial vasodilatory function is related to the proportions of saturated fatty acids and alpha-linolenic acid in young men, but not in women. Eur J Clin Invest 2003; 33:390-6. [PMID: 12713452 DOI: 10.1046/j.1365-2362.2003.01147.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Fatty acid composition of serum lipids is associated with cardiovascular disease. As attenuated endothelium-dependent vasodilation (EDV) is an early event in atherosclerosis, we investigated the relationships between endothelial vasodilatory function and the proportion of serum fatty acids, reflecting dietary fat quality, in 74 healthy men and women, aged 20-30 years. DESIGN Endothelium-dependent vasodilation and endothelium-independent vasodilation (EIDV) was studied in the forearm during local administration of methacholine (2 and 4 micro g min-1) and nitroprusside (5 and 10 micro g min-1). Forearm blood flow was determined with venous occlusion plethysmography. An endothelial function index was calculated as the EDV/EIDV ratio. RESULTS The endothelial function index was inversely related to the total proportion of saturated fatty acids (r = -0.41, P < 0.05), in particular lauric and myristic acid (r = -0.37 and r = -0.36, respectively, P < 0.05 for both), and was positively related to the proportion of alpha-linolenic acid (r = 0.45, P < 0.01) in men only. Total serum nonesterified fatty acid (NEFA) concentration was not significantly related to endothelial vasodilatory function. By multiple stepwise regression analysis, including age, blood pressure, body mass index, and serum cholesterol, triglyceride and NEFA as confounders, myristic acid and alpha-linolenic acid were independent predictors of the endothelial function index in men only (r = -0.39 and r = 0.47, respectively, P < 0.01 for both). CONCLUSIONS We conclude that serum fatty acid composition predicts endothelial vasodilatory dysfunction independently of serum NEFA and cholesterol levels in young, healthy men in their third decade of life, whereas fatty acid composition seems to be less important in women at this age. As a result of the large number of analyses performed, these findings need to be verified by other studies.
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Affiliation(s)
- P Steer
- University Hospital, Uppsala, Sweden
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Mayhan WG, Sharpe GM. Acute and chronic treatment with nicotine impairs reactivity of arterioles in response to activation of potassium channels. J Cardiovasc Pharmacol 2002; 39:695-703. [PMID: 11973413 DOI: 10.1097/00005344-200205000-00010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Although acute and chronic treatment with nicotine impairs nitric oxide synthase-dependent responses of large and small blood vessels, the effect of nicotine on other vasodilator pathways remains uncertain. The goal of the current study was to determine effects of nicotine on dilatation of arterioles to activation of ATP-sensitive potassium channels. Reactivity of cheek pouch arterioles ( approximately 50 microm) was measured during acute (1-2 h) and chronic (2-to 3-week) exposure to nicotine in response to aprikalim, cromakalim, and nitroglycerin. Acute treatment with nicotine impaired dilatation of arterioles in response to aprikalim and cromakalim but not nitroglycerin. Aprikalim and cromakalim (1.0 microM) dilated arterioles by 37 +/- 5% and 30 +/- 3%, respectively, before, but by only 21 +/- 4% and 16 +/- 3%, respectively, after infusion of nicotine (p < 0.05). Chronic exposure to nicotine did not alter vasodilatation to nitroglycerin but impaired vasodilatation to aprikalim and cromakalim. In vehicle-treated hamsters, aprikalim and cromakalim (1.0 microM) dilated arterioles by 28 +/- 1% and 32 +/- 3%, respectively. However, in nicotine-treated hamsters aprikalim and cromakalim (1.0 microM) dilated arterioles by only 3 +/- 1% and 13 +/- 1%, respectively. Next, the role of superoxide anion in impaired responses of arterioles to aprikalim and cromakalim during acute infusion of nicotine was examined. Treatment with superoxide dismutase attenuated the effects of nicotine on aprikalim and cromakalim. Thus, acute and chronic exposure to nicotine has profound affects on vasodilatation to activation of ATP-sensitive potassium channels, which may be mediated by superoxide anion.
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Affiliation(s)
- William G Mayhan
- Department of Physiology and Biophysics, University of Nebraska Medical Center, Omaha 68198-4575, USA.
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Pretorius M, Rosenbaum DA, Lefebvre J, Vaughan DE, Brown NJ. Smoking impairs bradykinin-stimulated t-PA release. Hypertension 2002; 39:767-71. [PMID: 11897760 DOI: 10.1161/hy0302.105767] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Bradykinin stimulates tissue plasminogen activator release from human endothelium through a flow-independent, B2 receptor-dependent mechanism. The present study tests the hypothesis that smoking impairs bradykinin-stimulated tissue plasminogen activator release. Graded doses of nitroprusside (1.6 to 6.4 microg/min), methacholine (3.2 to 12.8 microg/min), and bradykinin (100 to 400 ng/min) were infused in the brachial artery in random order in 20 smokers and 12 nonsmokers matched for age, gender, and body mass index. Forearm blood flow was measured by strain-gauge plethysmography. All 3 drugs caused a dose-dependent increase in forearm blood flow, with no significant difference between smokers and nonsmokers. Bradykinin (P=0.001) and methacholine (P=0.001) caused significant dose-dependent increases in net tissue plasminogen activator release. The tissue plasminogen activator response to bradykinin was significantly greater than the tissue plasminogen activator response to methacholine in the nonsmokers (maximal net tissue plasminogen activator release, 73.2+/-21.5 versus 27.6+/-7.2 ng/min per 100 mL; P=0.001) but not in the smokers (maximal net tissue plasminogen activator release, 44.5+/-10.7 versus 24.8+/-9.3 ng/min per 100 mL; P=0.154). The effect of bradykinin (P=0.037), but not methacholine (P=0.978), on net tissue plasminogen activator release was significantly reduced in smokers compared with nonsmokers. The vascular tissue plasminogen activator response to bradykinin, but not methacholine, is impaired in smokers. Stimulated tissue plasminogen activator release may be a more sensitive measure of endothelial function than vasodilation.
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Affiliation(s)
- Mias Pretorius
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232-6602, USA
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Abstract
Caffeine and nicotine are the most common psychostimulant drugs used worldwide. Structural neuroimaging findings associated with caffeine and nicotine consumption are limited and primarily reflect the putative relationship between smoking and white matter hyperintensities (WMH), a finding that warrants further appraisal of its clinical implications. The application of newer brain imaging modalities that measure subtle haemodynamic changes or tissue-based chemistry in order to better elucidate brain functional processes, including mechanisms underlying addiction to nicotine and caffeine and the brain functional consequences, provide intriguing findings. Potential influences of caffeine and nicotine on the functional contrast, or metabolic response, to neural activation also necessitates the careful appraisal of the effects that these commonly used drugs may have on the results of functional imaging.
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Affiliation(s)
- S R Dager
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle 98105-6099, USA.
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