1
|
Basic Concepts of the Microcirculation. Microcirculation 2020. [DOI: 10.1007/978-3-030-28199-1_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
2
|
Abstract
The heart is uniquely responsible for providing its own blood supply through the coronary circulation. Regulation of coronary blood flow is quite complex and, after over 100 years of dedicated research, is understood to be dictated through multiple mechanisms that include extravascular compressive forces (tissue pressure), coronary perfusion pressure, myogenic, local metabolic, endothelial as well as neural and hormonal influences. While each of these determinants can have profound influence over myocardial perfusion, largely through effects on end-effector ion channels, these mechanisms collectively modulate coronary vascular resistance and act to ensure that the myocardial requirements for oxygen and substrates are adequately provided by the coronary circulation. The purpose of this series of Comprehensive Physiology is to highlight current knowledge regarding the physiologic regulation of coronary blood flow, with emphasis on functional anatomy and the interplay between the physical and biological determinants of myocardial oxygen delivery. © 2017 American Physiological Society. Compr Physiol 7:321-382, 2017.
Collapse
Affiliation(s)
- Adam G Goodwill
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN
| | - Gregory M Dick
- California Medical Innovations Institute, 872 Towne Center Drive, Pomona, CA
| | - Alexander M Kiel
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Drive, Lafayette, IN
| | - Johnathan D Tune
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN
| |
Collapse
|
3
|
Grossini E, Raina G, Farruggio S, Camillo L, Molinari C, Mary D, Walker GE, Bona G, Vacca G, Moia S, Prodam F, Surico D. Intracoronary Des-Acyl Ghrelin Acutely Increases Cardiac Perfusion Through a Nitric Oxide-Related Mechanism in Female Anesthetized Pigs. Endocrinology 2016; 157:2403-15. [PMID: 27100620 DOI: 10.1210/en.2015-1922] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Des-acyl ghrelin (DAG), the most abundant form of ghrelin in humans, has been found to reduce arterial blood pressure and prevent cardiac and endothelial cell apoptosis. Despite this, data regarding its direct effect on cardiac function and coronary blood flow, as well as the related involvement of autonomic nervous system and nitric oxide (NO), are scarce. We therefore examined these issues using both in vivo and in vitro studies. In 20 anesthetized pigs, intracoronary 100 pmol/mL DAG infusion with a constant heart rate and aortic blood pressure, increased coronary blood flow and NO release, whereas reducing coronary vascular resistances (P < .05). Dose responses to DAG were evaluated in five pigs. No effects on cardiac contractility/relaxation or myocardial oxygen consumption were observed. Moreover, whereas the blockade of muscarinic cholinoceptors (n = 5) or α- and β-adrenoceptors (n = 5 each) did not abolish the observed responses, NO synthase inhibition (n = 5) prevented the effects of DAG on coronary blood flow and NO release. In coronary artery endothelial cells, DAG dose dependently increased NO release through cAMP signaling and ERK1/2, Akt, and p38 MAPK involvement as well as the phosphorylation of endothelial NO synthase. In conclusion, in anesthetized pigs, DAG primarily increased cardiac perfusion through the involvement of NO release. Moreover, the phosphorylation of ERK1/2 and Akt appears to play roles in eliciting the observed NO production in coronary artery endothelial cells.
Collapse
Affiliation(s)
- Elena Grossini
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Giulia Raina
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Serena Farruggio
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Lara Camillo
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Claudio Molinari
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - David Mary
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Gillian Elisabeth Walker
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Gianni Bona
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Giovanni Vacca
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Stefania Moia
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Flavia Prodam
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Daniela Surico
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| |
Collapse
|
4
|
Takács H, Kui P, Farkas AS, Sarusi A, Forster T, Papp JG, Varró A, Curtis MJ, Shattock MJ, Farkas A. Ventricular cycle length irregularity affects the correlation between ventricular rate and coronary flow in isolated, Langendorff perfused guinea pig hearts. J Pharmacol Toxicol Methods 2015; 77:45-52. [PMID: 26455880 DOI: 10.1016/j.vascn.2015.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Heart rate affects coronary flow, but the mechanism is complex. The relationship between rhythm and flow is unclear, especially in experimental settings used for determining drug actions. The present study examined whether ventricular irregularity influences coronary flow independently of heart rate. METHODS Guinea pig hearts were perfused (Langendorff mode) at constant pressure. Hypokalemic Krebs solution facilitated spontaneous development of arrhythmias. The ECG, left ventricular and perfusion pressures were recorded, and the coronary flow was measured. Beat-to-beat ventricular cycle length variability was quantified. Hearts were retrospectively allocated to arbitrary 'Low' or 'High' RR variability groups. RESULTS A positive linear correlation was found between mean ventricular rate and coronary flow. The slope of the regression line was significantly greater in the 'High' versus 'Low' RR variability group, with greater coronary flow values in the 'High' RR variability group in the physiological heart rate range. During regular rhythm, left ventricular pressure exceeded perfusion pressure and prevented coronary perfusion at peak systole. However, ventricular irregularity significantly increased the number of beats in which left ventricular pressure remained below perfusion pressure, facilitating coronary perfusion. DISCUSSION In isolated hearts, cycle length irregularity increases the slope of the positive linear correlation between mean ventricular rate and coronary flow via producing beats in which left ventricular pressure remains below perfusion pressure. This means that changes in rhythm have the capacity to influence coronary flow independently of heart rate in isolated hearts perfused at constant pressure, which should be noted in drug studies on arrhythmias performed in Langendorff hearts.
Collapse
Affiliation(s)
- Hedvig Takács
- Second Department of Medicine and Cardiology Centre, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Péter Kui
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Attila S Farkas
- Second Department of Medicine and Cardiology Centre, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Annamária Sarusi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Tamás Forster
- Second Department of Medicine and Cardiology Centre, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Julius Gy Papp
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary; MTA-SZTE Research Group for Cardiovascular Pharmacology, Hungarian Academy of Sciences, Hungary
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | | | | | - András Farkas
- Second Department of Medicine and Cardiology Centre, Faculty of Medicine, University of Szeged, Szeged, Hungary.
| |
Collapse
|
5
|
Siegrist PT, Koepfli P, Namdar M, Pazhenkottil AP, Nkoulou R, Lüscher TF, Kaufmann PA. Recovery mismatch between myocardial blood flow and cardiac workload after physical exercise: a positron emission tomography study. Eur Heart J Cardiovasc Imaging 2014; 15:1386-90. [PMID: 25187616 DOI: 10.1093/ehjci/jeu141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS We studied the interrelation between oxygen consumption and myocardial blood flow (MBF) during recovery. MBF is directly dependent on oxygen consumption. The latter is linearly related to the heart rate-blood pressure product (RPP, bpm × mmHg), an index reflecting external cardiac work. In the immediate post-exercise period, cardiac output decreases considerably. This is expected to be paralleled by a rapid fall in oxygen demand, rendering ischaemia unlikely. Thus, the phenomenon of ST-segment depression during recovery remains unexplained. METHODS AND RESULTS (15)O-labelled water and positron emission tomography were used to measure MBF in 14 young healthy volunteers (mean age 27 ± 3 years) during the following study conditions: (i) at rest, (ii) during a steady submaximal supine bicycle exercise stress within the scanner, and (iii) during recovery immediately after cessation of exercise. During recovery, RPP decreased by 43% (18 768 ± 1337 vs. 11 652 ± 3224, P < 0.001). In contrast, the associated decrease in MBF (2.52 ± 0.52 vs. 1.93 ± 0.50 mL/min/g, P < 0.001) and perfusion reserve (2.68 ± 0.51 vs. 2.03 ± 0.42, P < 0.001) was significantly less pronounced (-24%, P < 0.01), indicating a relative delay in MBF recovery compared with cardiac work load. CONCLUSION The mismatch between a rapid decrease in cardiac workload but preserved hyperaemic response early after cessation of physical exercise suggests an uncoupling of cardiac work and MBF during recovery.
Collapse
Affiliation(s)
- Patrick T Siegrist
- Nuclear Medicine, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Pascal Koepfli
- Nuclear Medicine, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Mehdi Namdar
- Nuclear Medicine, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Aju P Pazhenkottil
- Nuclear Medicine, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Rene Nkoulou
- Nuclear Medicine, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Thomas F Lüscher
- Cardiology, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Philipp A Kaufmann
- Nuclear Medicine, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| |
Collapse
|
6
|
Ward JS, Coats J, Ramcharan M, Humphries K, Tong T, Chu C. Thoracolumbar spinal manipulation and the immediate impact on exercise performance. J Chiropr Med 2013; 11:233-41. [PMID: 23843754 DOI: 10.1016/j.jcm.2012.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 09/20/2012] [Accepted: 10/06/2012] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE The purpose of this study was to determine if thoracolumbar chiropractic manipulative therapy (CMT) had an immediate impact on exercise performance by measuring blood lactate concentration, exercise heart rate, and rating of perceived exertion during a treadmill-based graded exercise test (GXT). METHODS Ten healthy, asymptomatic male and 10 female college students (age = 27.5 ± 3.7 years, height = 1.68 ± 0.09 m, body mass = 71.3 ± 11.6 kg: mean ± SD) were equally randomized into an AB:BA crossover study design. Ten participants were in the AB group, and 10 were in the BA group. The study involved 1 week of rest in between each of the 2 conditions: A (prone Diversified T12-L1 CMT) vs B (no CMT). Participants engaged in a treadmill GXT 5 minutes after each week's condition (A or B). Outcome measures were blood lactate concentration, exercise heart rate, and rating of perceived exertion monitored at the conclusion of each 3-minute stage of the GXT. The exercise test continued until the participant achieved greater than 8 mmol/L blood lactate, which correlates with maximal to near-maximal exercise effort. A dependent-samples t test was used to make comparisons between A and B conditions related to exercise performance. RESULTS No statistically significant difference was shown among any exercise response dependent variables in this study. CONCLUSIONS The results of this research preliminarily suggest that CMT to T12-L1 does not immediately impact exercise performance during a treadmill-based GXT using healthy college students.
Collapse
Affiliation(s)
- John S Ward
- Assistant Professor/Research Fellow, Department of Physiology and Chemistry, Texas Chiropractic College, Pasadena, TX
| | | | | | | | | | | |
Collapse
|
7
|
Merkus D, Visser M, Houweling B, Zhou Z, Nelson J, Duncker DJ. Phosphodiesterase 5 inhibition-induced coronary vasodilation is reduced after myocardial infarction. Am J Physiol Heart Circ Physiol 2013; 304:H1370-81. [DOI: 10.1152/ajpheart.00410.2012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The balance between the production and removal of cGMP in coronary vascular smooth muscle is of critical importance in determining coronary vasomotor tone and thus in the regulation of coronary blood flow. cGMP production by soluble guanylyl cyclase is activated by nitric oxide (NO), whereas cGMP breakdown occurs through phosphodiesterase 5 (PDE5). We hypothesized that myocardial infarction (MI) alters the balance between the production and removal of cGMP in the coronary vasculature and thereby alters the control of coronary vasomotor tone. Chronically instrumented swine with and without a 2-wk-old MI were exercised on a treadmill in the absence and presence of the PDE5 inhibitor EMD-360527 (300 μg·kg−1·min−1 iv). Inhibition of PDE5 produced coronary resistance vessel dilation, which was more pronounced at rest than during exercise in normal swine. PDE5 gene expression was markedly reduced in coronary resistance vessels isolated from the remote myocardium of MI swine, which was accompanied by a similarly marked attenuation of coronary vasodilation by PDE5 inhibition in MI swine. The coronary vasoconstriction produced by inhibition of NO synthesis with Nω-nitro-l-arginine (20 mg/kg iv) was only slightly smaller in swine with MI. Interestingly, inhibition of NO synthesis reduced the vasodilator response to subsequent PDE5 inhibition in normal swine but not in MI swine. Conversely, PDE5 inhibition enhanced the coronary vasoconstriction produced by NO synthesis inhibition in normal swine but not in MI swine, suggesting that downregulation of PDE5 mitigated the loss of NO vasodilator influence. In conclusion, the expression and vasoconstrictor influence of PDE5 are markedly attenuated in coronary resistance vessels in the remote myocardium after MI, which appears to serve as a compensatory mechanism to mitigate the loss of NO vasodilator influence.
Collapse
Affiliation(s)
- Daphne Merkus
- Experimental Cardiology, Thoraxcenter, Cardiovascular Research Institute, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marleen Visser
- Experimental Cardiology, Thoraxcenter, Cardiovascular Research Institute, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Birgit Houweling
- Experimental Cardiology, Thoraxcenter, Cardiovascular Research Institute, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Zhichao Zhou
- Experimental Cardiology, Thoraxcenter, Cardiovascular Research Institute, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Jessica Nelson
- Experimental Cardiology, Thoraxcenter, Cardiovascular Research Institute, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Dirk J. Duncker
- Experimental Cardiology, Thoraxcenter, Cardiovascular Research Institute, Erasmus University Medical Center, Rotterdam, The Netherlands
| |
Collapse
|
8
|
Exercise perspective on common cardiac medications. Integr Med Res 2013; 2:49-55. [PMID: 28664054 PMCID: PMC5481675 DOI: 10.1016/j.imr.2013.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 04/15/2013] [Accepted: 04/15/2013] [Indexed: 12/20/2022] Open
Abstract
Medicinal tablets have been used for a long time to treat cardiovascular disease. However, mortality rate is steadily increasing partly because of the patients’ sedentary lifestyle and unhealthy diet. By contrast, exercise has been systematically shown to have multiple benefits. Regular exercise training can prevent various diseases in healthy individuals. Combined exercise and cardiac medications may lead to the improvement of heart disease. Numerous exercise training pathways still need further investigations. How exercise can prevent, treat, or attenuate diseases remains somewhat elusive. Thus, this review will discuss cardiac medications in parallel with the mechanism of action of exercise.
Collapse
|
9
|
Chen JF, Eltzschig HK, Fredholm BB. Adenosine receptors as drug targets--what are the challenges? Nat Rev Drug Discov 2013; 12:265-86. [PMID: 23535933 PMCID: PMC3930074 DOI: 10.1038/nrd3955] [Citation(s) in RCA: 650] [Impact Index Per Article: 59.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Adenosine signalling has long been a target for drug development, with adenosine itself or its derivatives being used clinically since the 1940s. In addition, methylxanthines such as caffeine have profound biological effects as antagonists at adenosine receptors. Moreover, drugs such as dipyridamole and methotrexate act by enhancing the activation of adenosine receptors. There is strong evidence that adenosine has a functional role in many diseases, and several pharmacological compounds specifically targeting individual adenosine receptors--either directly or indirectly--have now entered the clinic. However, only one adenosine receptor-specific agent--the adenosine A2A receptor agonist regadenoson (Lexiscan; Astellas Pharma)--has so far gained approval from the US Food and Drug Administration (FDA). Here, we focus on the biology of adenosine signalling to identify hurdles in the development of additional pharmacological compounds targeting adenosine receptors and discuss strategies to overcome these challenges.
Collapse
Affiliation(s)
- Jiang-Fan Chen
- Department of Neurology and Pharmacology, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | | | | |
Collapse
|
10
|
Duncker DJ, Bache RJ, Merkus D. Regulation of coronary resistance vessel tone in response to exercise. J Mol Cell Cardiol 2012; 52:802-13. [DOI: 10.1016/j.yjmcc.2011.10.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 09/18/2011] [Accepted: 10/08/2011] [Indexed: 10/16/2022]
|
11
|
Zhou Z, Hemradj V, de Beer VJ, Gao F, Hoekstra M, Merkus D, Duncker DJ. Cytochrome P-450 2C9 exerts a vasoconstrictor influence on coronary resistance vessels in swine at rest and during exercise. Am J Physiol Heart Circ Physiol 2012; 302:H1747-55. [PMID: 22307673 DOI: 10.1152/ajpheart.00648.2011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A significant endothelium-dependent vasodilation persists after inhibition of nitric oxide synthase (NOS) and cyclooxygenase (COX) in the coronary vasculature, which has been linked to the activation of cytochrome P-450 (CYP) epoxygenases expressed in endothelial cells and subsequent generation of vasodilator epoxyeicosatrienoic acids. Here, we investigated the contribution of CYP 2C9 metabolites to regulation of porcine coronary vasomotor tone in vivo and in vitro. Twenty-six swine were chronically instrumented. Inhibition of CYP 2C9 with sulfaphenazole (5 mg/kg iv) alone had no effect on bradykinin-induced endothelium-dependent coronary vasodilation in vivo but slightly attenuated bradykinin-induced vasodilation in the presence of combined NOS/COX blockade with N(ω)-nitro-L-arginine (20 mg/kg iv) and indomethacin (10 mg/kg iv). Sulfaphenazole had minimal effects on coronary resistance vessel tone at rest or during exercise. Surprisingly, in the presence of combined NOS/COX blockade, a significant coronary vasodilator response to sulfaphenzole became apparent, both at rest and during exercise. Subsequently, we investigated in isolated porcine coronary small arteries (∼250 μm) the possible involvement of reactive oxygen species (ROS) in the paradoxical vasoconstrictor influence of CYP 2C9 activity. The vasodilation by bradykinin in vitro in the presence of NOS/COX blockade was markedly potentiated by sulfaphenazole under control conditions but not in the presence of the ROS scavenger N-(2-mercaptoproprionyl)-glycine. In conclusion, CYP 2C9 can produce both vasoconstrictor and vasodilator metabolites. Production of these metabolites is enhanced by combined NOS/COX blockade and is critically dependent on the experimental conditions. Thus production of vasoconstrictors slightly outweighed the production of vasodilators at rest and during exercise. Pharmacological stimulation with bradykinin resulted in vasodilator CYP 2C9 metabolite production when administered in vivo, whereas vasoconstrictor CYP 2C9 metabolites, most likely ROS, were dominant when administered in vitro.
Collapse
Affiliation(s)
- Zhichao Zhou
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School Erasmus University Rotterdam, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
12
|
Leonard S, Croy BA, Murrant CL. Arteriolar reactivity in lymphocyte-deficient mice. Am J Physiol Heart Circ Physiol 2011; 301:H1276-85. [DOI: 10.1152/ajpheart.00346.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mounting evidence suggests that lymphocytes have the capacity to contribute to the regulation of systemic circulatory control. We postulated that T and natural killer (NK) cells could modify basal microvascular activity under physiologically normal conditions. In situ intravital microscopy of mouse cremaster vasculature was used to evaluate arteriolar reactivities to the vasoconstrictors angiotensin II (ANG II) and phenylephrine (Phe) and the vasodilators acetylcholine (ACh) and adenosine (Ado) in normal [+/+; wild type (WT)] and genetically immunodeficient (T−B−NK+ or T−B−\NK−) C57BL/6 and BALB/c mice, strain backgrounds with differentially polarized T cell cytokine production. Immunodeficient mice tended to have smaller baseline and maximal diameters of third-order cremaster arterioles than their congenic WT partners. In C57BL/6, baseline diameters were similar in T-B− mice without or with NK cells; in BALB/c, baseline diameters were larger in T-B-NK− mice than in T−B−NK+ mice. Thus, at baseline, lymphocytes tended to promote vasodilation, except BALB/c NK cells, which mediated mild vasoconstriction. The presence of NK cells suppressed dilations to Ado in both strains, to ACh in the C57BL/6 strain, and dilatory responses to ANG II in C57BL/6 and to Phe in BALB/c. In the BALB/c strain, the presence of T and B cells promoted vasodilatory responses to Ado, attenuated dilations to low ACh concentrations, and exaggerated dilation and constriction responses to ANG II. Thus, under agonist challenge, NK cells generally promote constriction, whereas influences of T and B cells depend upon the stimulus. Therefore, lymphocytes or their products have physiological influences on microvascular arteriolar reactivity.
Collapse
Affiliation(s)
- Sean Leonard
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario; and
| | - B. Anne Croy
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Coral L. Murrant
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario; and
| |
Collapse
|
13
|
de Beer VJ, Taverne YJ, Kuster DW, Najafi A, Duncker DJ, Merkus D. Prostanoids suppress the coronary vasoconstrictor influence of endothelin after myocardial infarction. Am J Physiol Heart Circ Physiol 2011; 301:H1080-9. [PMID: 21685265 DOI: 10.1152/ajpheart.01307.2010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myocardial infarction (MI) is associated with endothelial dysfunction resulting in an imbalance in endothelium-derived vasodilators and vasoconstrictors. We have previously shown that despite increased endothelin (ET) plasma levels, the coronary vasoconstrictor effect of endogenous ET is abolished after MI. In normal swine, nitric oxide (NO) and prostanoids modulate the vasoconstrictor effect of ET. In light of the interaction among NO, prostanoids, and ET combined with endothelial dysfunction present after MI, we investigated this interaction in control of coronary vasomotor tone in the remote noninfarcted myocardium after MI. Studies were performed in chronically instrumented swine (18 normal swine; 13 swine with MI) at rest and during treadmill exercise. Furthermore, endothelial nitric oxide synthase (eNOS) and cyclooxygenase protein levels were measured in the anterior (noninfarcted) wall of six normal and six swine with MI. eNOS inhibition with N(ω)-nitro-L-arginine (L-NNA) and cyclooxygenase inhibition with indomethacin each resulted in coronary vasoconstriction at rest and during exercise, as evidenced by a decrease in coronary venous oxygen levels. The effect of l-NNA was slightly decreased in swine with MI, although eNOS expression was not altered. Conversely, in accordance with the unaltered expression of cyclooxygenase-1 after MI, the effect of indomethacin was similar in normal and MI swine. L-NNA enhanced the vasodilator effect of the ET(A/B) receptor blocker tezosentan but exclusively during exercise in both normal and MI swine. Interestingly, this effect of L-NNA was blunted in MI compared with normal swine. In contrast, whereas indomethacin increased the vasodilator effect of tezosentan only during exercise in normal swine, indomethacin unmasked a coronary vasodilator effect of tezosentan in MI swine both at rest and during exercise. In conclusion, the present study shows that endothelial control of the coronary vasculature is altered in post-MI remodeled myocardium. Thus the overall vasodilator influences of NO as well as its inhibition of the vasoconstrictor influence of ET on the coronary resistance vessels were reduced after MI. In contrast, while the overall prostanoid vasodilator influence was maintained, its inhibition of ET vasoconstrictor influences was enhanced in post-MI remote myocardium.
Collapse
Affiliation(s)
- Vincent J de Beer
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
14
|
|
15
|
Kuster DWD, Merkus D, van der Velden J, Verhoeven AJM, Duncker DJ. 'Integrative Physiology 2.0': integration of systems biology into physiology and its application to cardiovascular homeostasis. J Physiol 2011; 589:1037-45. [PMID: 21224228 DOI: 10.1113/jphysiol.2010.201533] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Since the completion of the Human Genome Project and the advent of the large scaled unbiased '-omics' techniques, the field of systems biology has emerged. Systems biology aims to move away from the traditional reductionist molecular approach, which focused on understanding the role of single genes or proteins, towards a more holistic approach by studying networks and interactions between individual components of networks. From a conceptual standpoint, systems biology elicits a 'back to the future' experience for any integrative physiologist. However, many of the new techniques and modalities employed by systems biologists yield tremendous potential for integrative physiologists to expand their tool arsenal to (quantitatively) study complex biological processes, such as cardiac remodelling and heart failure, in a truly holistic fashion. We therefore advocate that systems biology should not become/stay a separate discipline with '-omics' as its playing field, but should be integrated into physiology to create 'Integrative Physiology 2.0'.
Collapse
Affiliation(s)
- Diederik W D Kuster
- Experimental Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | | | | | | | | |
Collapse
|
16
|
Chies AB, de Souza Rossignoli P, Daniel EF. Exercise increases the angiotensin II effects in isolated portal vein of trained rats. Peptides 2010; 31:883-8. [PMID: 20172009 DOI: 10.1016/j.peptides.2010.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 02/11/2010] [Accepted: 02/12/2010] [Indexed: 12/17/2022]
Abstract
Training in rats adapts the portal vein to respond vigorously to sympathetic stimuli even when the animal is re-exposed to exercise. Moreover, changes in the exercise-induced effects of angiotensin II, a potent venoconstrictor agonist, in venous beds remain to be investigated. Therefore, the present study aimed to assess the effects of angiotensin II in the portal vein and vena cava from sedentary and trained rats at rest or submitted to an exercise session immediately before organ bath experiments. We found that training or exposure of sedentary animals to a single bout of running exercise does not significantly change the responses of the rat portal vein to angiotensin II. However, the exposure of trained animals to a single bout of running exercise enhanced the response of the rat portal vein to angiotensin II. This enhancement appeared to be territory-specific because it was not observed in the vena cava. Moreover, it was not observed in endothelium-disrupted preparations and in preparations treated with N(omega)-nitro-l-arginine methyl ester hydrochloride, indomethacin, BQ-123 or BQ-788. These data indicate that training causes adaptations in the rat portal vein that respond vigorously to angiotensin II even upon re-exposure to exercise. This increased response to angiotensin II requires an enhancement of the vasocontractile influence of endothelin beyond the influence of nitric oxide and vasodilator prostanoids.
Collapse
Affiliation(s)
- Agnaldo Bruno Chies
- Laboratory of Pharmacology, Faculty of Medicine of Marília, Av. Monte Carmelo, 800, Fragata, 17 519-030, Marília, SP, Brazil.
| | | | | |
Collapse
|
17
|
Mather KJ, Lteif AA, Veeneman E, Fain R, Giger S, Perry K, Hutchins GD. Role of endogenous ET-1 in the regulation of myocardial blood flow in lean and obese humans. Obesity (Silver Spring) 2010; 18:63-70. [PMID: 19543207 DOI: 10.1038/oby.2009.196] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Endothelin is an important determinant of peripheral vascular tone, and increased endogenous endothelin activity contributes to peripheral vascular dysfunction in human obesity. The contributions of endothelin to the regulation of coronary vascular tone in health in humans have not been well studied. We hypothesized that the contribution of endothelin to the regulation of myocardial perfusion would be augmented in human obesity. Using [NH(3)]ammonia positron emission tomography (PET), we measured myocardial perfusion under resting and adenosine-stimulated conditions on two separate days, with and without concurrent exposure to BQ123, an antagonist of type A endothelin receptors (1 micromol/min IV beginning 90 min before measurement). We studied 10 lean and 9 obese subjects without hypertension, hyperlipidemia, or diabetes mellitus. We observed a BQ123-induced increase in resting myocardial perfusion of approximately 40%, not different between lean and obese subjects (BQ123-induced increase in flow: lean 0.12 +/- 0.20, obese 0.32 +/- 0.51 ml/g/min, P = 0.02 BQ123 effect, P = 0.27 comparing response across groups). Although basal flow rates varied by region of the myocardium, the BQ123 effect was seen in all regions. BMI and cholesterol were significantly related to BQ123-induced increases in basal tone in multivariable analysis. There was no baseline difference in the adenosine-stimulated increase in blood flow between lean and obese subjects, and BQ123 failed to augment these responses in either group. These observations suggest that endothelin is an important contributor to the regulation of myocardial perfusion under resting conditions in healthy lean and obese humans, with increased contributions in proportion to increasing obesity.
Collapse
Affiliation(s)
- Kieren J Mather
- Division of Endocrinology and Metabolism, Indiana University School of Medicine, Indianapolis, Indiana, USA.
| | | | | | | | | | | | | |
Collapse
|
18
|
Gao F, de Beer VJ, Hoekstra M, Xiao C, Duncker DJ, Merkus D. Both beta1- and beta2-adrenoceptors contribute to feedforward coronary resistance vessel dilation during exercise. Am J Physiol Heart Circ Physiol 2009; 298:H921-9. [PMID: 20035031 DOI: 10.1152/ajpheart.00135.2009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
During exercise, beta-feedforward coronary vasodilation has been shown to contribute to the matching of myocardial oxygen supply with the demand of the myocardium. Since both beta(1)- and beta(2)-adrenoceptors are present in the coronary microvasculature, we investigated the relative contribution of these subtypes to beta-feedforward coronary vasodilation during exercise as well as to infusion of the beta(1)-agonist norepinephrine and the beta(1)- and beta(2)-agonist isoproterenol. Chronically instrumented swine were studied at rest and during graded treadmill exercise (1-5 km/h) under control conditions and after beta(1)-blockade with metoprolol (0.5 mg/kg iv) and beta(1)/beta(2)-blockade with propranolol (0.5 mg/kg iv). The selectivity and degree of beta-blockade of metoprolol and propranolol were confirmed using isoproterenol infusion (0.05-0.4 microg. kg(-1).min(-1)) under resting conditions. Isoproterenol-induced coronary vasodilation was mediated through the beta(2)-adrenoceptor, whereas norepinephrine-induced coronary vasodilation was principally mediated through the beta(1)-adrenoceptor. Exercise resulted in a significant increase in left ventricular norepinephrine release and epinephrine uptake. beta(1)-Adrenoceptor blockade with metoprolol had very little effect under resting conditions. However, during exercise, metoprolol attenuated the increase in myocardial oxygen supply in excess of the reduction in myocardial oxygen demand, as evidenced by a progressive decrease in coronary venous Po(2). Consequently, metoprolol caused a clockwise rotation of the relationship between myocardial oxygen consumption and coronary venous Po(2). Additional beta(2)-adrenoceptor blockade with propranolol further inhibited myocardial oxygen supply during exercise, resulting in a further clockwise rotation of the relationship between myocardial oxygen consumption and coronary venous Po(2). In conclusion, both beta(1)- and beta(2)-adrenoceptors contribute to the beta-feedforward coronary resistance vessel dilation during exercise.
Collapse
Affiliation(s)
- Fen Gao
- Dept. of Cardiology, Univ. Medical Center Rotterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
19
|
Chies AB, de Souza Rossignoli P. Exercise increases the phenylephrine effects in isolated portal vein of trained rats. Vascul Pharmacol 2009; 51:125-32. [DOI: 10.1016/j.vph.2009.05.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 03/20/2009] [Accepted: 05/28/2009] [Indexed: 10/20/2022]
|
20
|
de Beer VJ, Sorop O, Pijnappels DA, Dekkers DH, Boomsma F, Lamers JMJ, Duncker DJ, Merkus D. Integrative control of coronary resistance vessel tone by endothelin and angiotensin II is altered in swine with a recent myocardial infarction. Am J Physiol Heart Circ Physiol 2008; 294:H2069-77. [DOI: 10.1152/ajpheart.01163.2007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Several studies have indicated an interaction between the renin-angiotensin (ANG II) system and endothelin (ET) in the regulation of vascular tone. Previously, we have shown that both ET and ANG II exert a vasoconstrictor influence on the coronary resistance vessels of awake normal swine. Here, we investigated whether the interaction between ANG II and ET exists in the control of coronary resistance vessel tone at rest and during exercise using single and combined blockade of angiotensin type 1 (AT1) and ETA/ETB receptors. Since both circulating ANG II and ET levels are increased after myocardial infarction (MI), we investigated if the interaction between these systems is altered after MI. In awake healthy swine, coronary vasodilation in response to ETA/ETB receptor blockade in the presence of AT1 blockade was similar to vasodilation produced by ETA/ETB blockade under control conditions. In awake swine with a 2- to 3-wk-old MI, coronary vasodilator responses to individual AT1 and ETA/ETB receptor blockade were virtually abolished, despite similar coronary arteriolar AT1 and ETA receptor expression compared with normal swine. Unexpectedly, in the presence of AT1 blockade (which had no effect on circulating ET levels), ETA/ETB receptor blockade elicited a coronary vasodilator response. These findings suggest that in normal healthy swine the two vasoconstrictor systems contribute to coronary resistance vessel control in a linear additive manner, i.e., with negligible cross-talk. In contrast, in the remodeled myocardium, cross-talk between ANG II and ET emerges, resulting in nonlinear redundant control of coronary resistance vessel tone.
Collapse
|
21
|
|