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Electrophysiologic Effects of Growth Hormone Post-Myocardial Infarction. Int J Mol Sci 2020; 21:ijms21030918. [PMID: 32019245 PMCID: PMC7037853 DOI: 10.3390/ijms21030918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 01/26/2020] [Accepted: 01/28/2020] [Indexed: 02/05/2023] Open
Abstract
Myocardial infarction remains a major health-related problem with significant acute and long-term consequences. Acute coronary occlusion results in marked electrophysiologic alterations that can induce ventricular tachyarrhythmias such as ventricular tachycardia or ventricular fibrillation, often heralding sudden cardiac death. During the infarct-healing stage, hemodynamic and structural changes can lead to left ventricular dilatation and dysfunction, whereas the accompanying fibrosis forms the substrate for re-entrant circuits that can sustain ventricular tachyarrhythmias. A substantial proportion of such patients present clinically with overt heart failure, a common disease-entity associated with high morbidity and mortality. Several lines of evidence point toward a key role of the growth hormone/insulin-like growth factor-1 axis in the pathophysiology of post-infarction structural and electrophysiologic remodeling. Based on this rationale, experimental studies in animal models have demonstrated attenuated dilatation and improved systolic function after growth hormone administration. In addition to ameliorating wall-stress and preserving the peri-infarct myocardium, antiarrhythmic actions were also evident after such treatment, but the precise underlying mechanisms remain poorly understood. The present article summarizes the acute and chronic actions of systemic and local growth hormone administration in the post-infarction setting, placing emphasis on the electrophysiologic effects. Experimental and clinical data are reviewed, and hypotheses on potential mechanisms of action are discussed. Such information may prove useful in formulating new research questions and designing new studies that are expected to increase the translational value of growth hormone therapy after acute myocardial infarction.
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Lekkas P, Kontonika M, Georgiou ES, La Rocca V, Mouchtouri ET, Mourouzis I, Pantos C, Kolettis TM. Endothelin receptors in the brain modulate autonomic responses and arrhythmogenesis during acute myocardial infarction in rats. Life Sci 2019; 239:117062. [PMID: 31734261 DOI: 10.1016/j.lfs.2019.117062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/31/2019] [Accepted: 11/09/2019] [Indexed: 10/25/2022]
Abstract
AIMS Endothelin has been implicated in various processes in the brain, including the modulation of sympathetic responses. The present study examined the pathophysiologic role of brain endothelin-receptors in the setting of acute myocardial infarction, characterized by high incidence of ventricular tachyarrhythmias. MAIN METHODS We investigated the effects of intracerebroventricular administration of antagonists of endothelin-receptors ETA, ETB, or both, during a 24 h-observation period post-coronary ligation in (n = 70) rats. Continuous recording was performed via implanted telemetry transmitters, followed by arrhythmia-analysis and calculation of autonomic indices derived from heart rate variability. The regional myocardial electrophysiologic properties were assessed by monophasic action potentials and multi-electrode recordings. KEY FINDINGS Sympathetic-activity was decreased and vagal-activity was enhanced after intracerebroventricular ETA-receptor blockade, thus attenuating regional myocardial repolarization inhomogeneity. As a result, the incidence of ventricular tachyarrhythmias was markedly lower in this group. Such effects were also observed after intracerebroventricular blockade of ETB-, or both, ETA- and ETB-receptors, although to a lesser extent. SIGNIFICANCE ETA-receptors in the brain modulate sympathetic and vagal responses and alter arrhythmogenesis during evolving myocardial necrosis in rats. These findings provide insights into arrhythmogenic mechanisms during acute myocardial infarction and call for further investigation on the role of endothelin in the central autonomic network.
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Affiliation(s)
- Panagiotis Lekkas
- Cardiovascular Research Institute, Ioannina and Athens, Greece; Department of Physiology, Medical School, University of Ioannina, Greece
| | | | | | | | - Eleni-Taxiarchia Mouchtouri
- Cardiovascular Research Institute, Ioannina and Athens, Greece; Department of Cardiology, Medical School, University of Ioannina, Greece
| | - Iordanis Mourouzis
- Department of Pharmacology, Medical School, National & Kapodistrian University of Athens, Greece
| | - Constantinos Pantos
- Department of Pharmacology, Medical School, National & Kapodistrian University of Athens, Greece
| | - Theofilos M Kolettis
- Cardiovascular Research Institute, Ioannina and Athens, Greece; Department of Cardiology, Medical School, University of Ioannina, Greece.
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Kontonika M, Barka E, Roumpi M, Vilaeti AD, Baltogiannis GG, Vlahos AP, Agathopoulos S, Kolettis TM. Intra-myocardial growth hormone administration ameliorates arrhythmogenesis during ischemia–reperfusion in rats. J Electrocardiol 2017; 50:207-210. [DOI: 10.1016/j.jelectrocard.2016.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Indexed: 10/20/2022]
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Kontonika M, Barka E, Roumpi M, La Rocca V, Lekkas P, Daskalopoulos EP, Vilaeti AD, Baltogiannis GG, Vlahos AP, Agathopoulos S, Kolettis TM. Prolonged intra-myocardial growth hormone administration ameliorates post-infarction electrophysiologic remodeling in rats. Growth Factors 2017; 35:1-11. [PMID: 28264596 DOI: 10.1080/08977194.2017.1297432] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Experimental studies indicate improved ventricular function after treatment with growth hormone (GH) post-myocardial infarction, but its effect on arrhythmogenesis is unknown. Here, we assessed the medium-term electrophysiologic remodeling after intra-myocardial GH administration in (n = 33) rats. GH was released from an alginate scaffold, injected around the ischemic myocardium after coronary ligation. Two weeks thereafter, ventricular tachyarrhythmias were induced by programmed electrical stimulation. Monophasic action potentials were recorded from the infarct border, coupled with evaluation of electrical conduction and repolarization from a multi-electrode array. The arrhythmia score was lower in GH-treated rats than in alginate-treated rats or controls. The shape and the duration of the action potential at the infarct border were preserved, and repolarization-dispersion was attenuated after GH; moreover, voltage rise was higher and activation delay was shorter. GH normalized also right ventricular parameters. Intra-myocardial GH preserved electrical conduction and repolarization-dispersion at the infarct border and decreased the incidence of induced tachyarrhythmias in rats post-ligation. The long-term antiarrhythmic potential of GH merits further study.
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Affiliation(s)
- Marianthi Kontonika
- a Department of Cardiology , Medical School, University of Ioannina , Greece
- b Cardiovascular Research Institute , Ioannina , Greece
| | - Eleonora Barka
- b Cardiovascular Research Institute , Ioannina , Greece
- c Ceramics and Composites Laboratory, Department of Materials Science and Engineering , University of Ioannina , Ioannina , Greece
| | - Maria Roumpi
- b Cardiovascular Research Institute , Ioannina , Greece
- c Ceramics and Composites Laboratory, Department of Materials Science and Engineering , University of Ioannina , Ioannina , Greece
| | | | | | - Evangelos P Daskalopoulos
- b Cardiovascular Research Institute , Ioannina , Greece
- d Pole of Cardiovascular Research, Université Catholique de Louvain, Institut de Recherche Expérimentale et Clinique , Brussels , Belgium
| | | | | | - Antonios P Vlahos
- b Cardiovascular Research Institute , Ioannina , Greece
- e Pediatric Cardiology, Department of Child Health , Medical School, University of Ioannina , Ioannina , Greece
| | - Simeon Agathopoulos
- b Cardiovascular Research Institute , Ioannina , Greece
- c Ceramics and Composites Laboratory, Department of Materials Science and Engineering , University of Ioannina , Ioannina , Greece
| | - Theofilos M Kolettis
- a Department of Cardiology , Medical School, University of Ioannina , Greece
- b Cardiovascular Research Institute , Ioannina , Greece
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Kolettis TM, Kontonika M, Barka E, Daskalopoulos EP, Baltogiannis GG, Tourmousoglou C, Papalois A, Kyriakides ZS. Central Sympathetic Activation and Arrhythmogenesis during Acute Myocardial Infarction: Modulating Effects of Endothelin-B Receptors. Front Cardiovasc Med 2015; 2:6. [PMID: 26664878 PMCID: PMC4671362 DOI: 10.3389/fcvm.2015.00006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 02/10/2015] [Indexed: 12/15/2022] Open
Abstract
Sympathetic activation during acute myocardial infarction (MI) is an important arrhythmogenic mechanism, but the role of central autonomic inputs and their modulating factors remain unclear. Using the in vivo rat-model, we examined the effects of clonidine, a centrally acting sympatholytic agent, in the presence or absence of myocardial endothelin-B (ETB) receptors. We studied wild-type (n = 20) and ETB-deficient rats (n = 20) after permanent coronary ligation, with or without pretreatment with clonidine. Cardiac rhythm was continuously recorded for 24 h by implantable telemetry devices, coupled by the assessment of autonomic and heart failure indices. Sympathetic activation and arrhythmogenesis were more prominent in ETB-deficient rats during the early phase post-ligation. Clonidine improved these outcomes throughout the observation period in ETB-deficient rats, but only during the delayed phase in wild-type rats. However, this benefit was counterbalanced by atrioventricular conduction abnormalities and by higher incidence of heart failure, the latter particularly evident in ETB-deficient rats. Myocardial ETB-receptors attenuate the arrhythmogenic effects of central sympathetic activation during acute MI. ETB-receptor deficiency potentiates the sympatholytic effects of clonidine and aggravates heart failure. The interaction between endothelin and sympathetic responses during myocardial ischemia/infarction and its impact on arrhythmogenesis and left ventricular dysfunction merits further investigation.
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Affiliation(s)
| | | | - Eleonora Barka
- Cardiovascular Research Institute , Ioannina and Athens , Greece
| | | | | | | | - Apostolos Papalois
- Cardiovascular Research Institute , Ioannina and Athens , Greece ; Experimental Research Center ELPEN , Athens , Greece
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Daskalopoulos EP, Vilaeti AD, Barka E, Mantzouratou P, Kouroupis D, Kontonika M, Tourmousoglou C, Papalois A, Pantos C, Blankesteijn WM, Agathopoulos S, Kolettis TM. Attenuation of post-infarction remodeling in rats by sustained myocardial growth hormone administration. Growth Factors 2015; 33:250-8. [PMID: 26290214 DOI: 10.3109/08977194.2015.1072527] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Prevention of left ventricular remodeling is an important therapeutic target post-myocardial infarction. Experimentally, treatment with growth hormone (GH) is beneficial, but sustained local administration has not been thoroughly investigated. We studied 58 rats (322 ± 4 g). GH was administered via a biomaterial-scaffold, following in vitro and in vivo evaluation of degradation and drug-release curves. Treatment consisted of intra-myocardial injection of saline or alginate-hydrogel, with or without GH, 10 min after permanent coronary artery ligation. Echocardiographic and histologic remodeling-indices were examined 3 weeks post-ligation, followed by immunohistochemical evaluation of angiogenesis, collagen, macrophages and myofibroblasts. GH-release completed at 3 days and alginate-degradation at ∼7 days. Alginate + GH consistently improved left ventricular end-diastolic and end-systolic diameters, ventricular sphericity, wall tension index and infarct-thickness. Microvascular-density and myofibroblast-count in the infarct and peri-infarct areas were higher after alginate + GH. Macrophage-count and collagen-content did not differ between groups. Early, sustained GH-administration enhances angiogenesis and myofibroblast-activation and ameliorates post-infarction remodeling.
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Affiliation(s)
- Evangelos P Daskalopoulos
- a Department of Pharmacology , Cardiovascular Research Institute Maastricht, Maastricht University , Maastricht , The Netherlands
- b Cardiovascular Research Institute , Ioannina , Athens , Greece
| | - Agapi D Vilaeti
- b Cardiovascular Research Institute , Ioannina , Athens , Greece
| | - Eleonora Barka
- b Cardiovascular Research Institute , Ioannina , Athens , Greece
- c Ceramics and Composites Laboratory, Department of Materials Science and Engineering, University of Ioannina , Ioannina , Greece
| | - Polixeni Mantzouratou
- d Department of Pharmacology , Medical School, University of Athens , Athens , Greece
| | - Dimitrios Kouroupis
- e Department of Biomedical Research, Foundation for Research and Technology-Hellas , Institute of Molecular Biology and Biotechnology , Ioannina , Greece , and
| | | | | | - Apostolos Papalois
- b Cardiovascular Research Institute , Ioannina , Athens , Greece
- f Experimental Research Center ELPEN , Pikermi , Athens , Greece
| | - Constantinos Pantos
- d Department of Pharmacology , Medical School, University of Athens , Athens , Greece
| | - W Matthijs Blankesteijn
- a Department of Pharmacology , Cardiovascular Research Institute Maastricht, Maastricht University , Maastricht , The Netherlands
| | - Simeon Agathopoulos
- c Ceramics and Composites Laboratory, Department of Materials Science and Engineering, University of Ioannina , Ioannina , Greece
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Kolettis TM, Oikonomidis DL, Baibaki MEE, Barka E, Kontonika M, Tsalikakis DG, Papalois A, Kyriakides ZS. Endothelin B-receptors and sympathetic activation: impact on ventricular arrhythmogenesis during acute myocardial infarction. Life Sci 2014; 118:281-7. [PMID: 24503339 DOI: 10.1016/j.lfs.2014.01.069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/26/2013] [Accepted: 01/23/2014] [Indexed: 12/26/2022]
Abstract
AIMS We investigated the role of endothelin-B receptors on sympathetic activation originating from the adrenal gland or from the myocardium and its impact on arrhythmogenesis during acute myocardial infarction. MAIN METHODS We studied two groups of rats (n=120, 284±2 g), namely wild-type and ETB-deficient. Myocardial infarction was induced by permanent ligation of the left coronary artery and ventricular tachyarrhythmias were evaluated from continuous electrocardiographic recordings. Sympathetic activation, measured by indices of heart rate variability, was evaluated after adrenalectomy or catecholamine depletion induced by reserpine. Acute left ventricular failure was assessed by total animal activity. KEY FINDINGS Adrenalectomy decreased the total duration of tachyarrhythmias in ETB-deficient rats, but their incidence remained higher, compared to wild-type rats. After reserpine, heart rate variability indices and tachyarrhythmias were similar in the two groups during the initial, ischaemic phase. During evolving infarction, tachyarrhythmia duration was longer in ETB-deficient rats, despite lower sympathetic activation. Heart rate was lower in ETB-deficient rats throughout the 24-hour observation period, whereas activity was comparable in the two groups. SIGNIFICANCE Endothelin-B receptors modulate sympathetic activation during acute myocardial infarction not only in the ventricular myocardium, but also in the adrenal gland. Sympathetic activation markedly increases early-phase ventricular tachyarrhythmias, but other mechanisms involving the endothelin system underlie delayed arrhythmogenesis.
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Affiliation(s)
- Theofilos M Kolettis
- Department of Cardiology, University of Ioannina, Ioannina, Greece; Cardiovascular Research Institute, Ioannina and Athens, Greece.
| | | | - Maria-Eleni E Baibaki
- Department of Cardiology, University of Ioannina, Ioannina, Greece; Cardiovascular Research Institute, Ioannina and Athens, Greece; Experimental Research Center ELPEN, Pikermi, Athens, Greece
| | - Eleonora Barka
- Department of Materials Science and Engineering, University of Ioannina, Greece
| | - Marianthi Kontonika
- Department of Cardiology, University of Ioannina, Ioannina, Greece; Cardiovascular Research Institute, Ioannina and Athens, Greece
| | - Dimitrios G Tsalikakis
- Engineering Informatics and Telecommunications, University of Western Macedonia, Kozani, Greece
| | - Apostolos Papalois
- Cardiovascular Research Institute, Ioannina and Athens, Greece; Experimental Research Center ELPEN, Pikermi, Athens, Greece
| | - Zenon S Kyriakides
- Cardiovascular Research Institute, Ioannina and Athens, Greece; First Department of Cardiology, Red Cross Hospital, Athens, Greece
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Kolettis TM, Vilaeti AD, Tsalikakis DG, Zoga A, Valenti M, Tzallas AT, Papalois A, Iliodromitis EK. Effects of Pre- and Postconditioning on Arrhythmogenesis in the In Vivo Rat Model. J Cardiovasc Pharmacol Ther 2013; 18:376-85. [DOI: 10.1177/1074248413482183] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The antiarrhythmic potential of postconditioning in in vivo models remains poorly defined. We compared the effects of pre- and postconditioning on ventricular arrhythmogenesis against controls with and without reperfusion. Wistar rats (n = 40, 269 ± 3 g) subjected to ischemia (30 minutes)–reperfusion (24 hours) were assigned to the following groups: (1) preconditioning (2 cycles), (2) postconditioning (6 cycles), or (3) no intervention and were compared with (4) nonreperfused infarcts and (5) sham-operated animals. Infarct size was measured, and arrhythmogenesis was evaluated with continuous telemetric electrocardiographic recording, heart rate variability indices, and monophasic action potentials (MAPs). During a 24-hour observation period, no differences in mortality were observed. Reperfusion decreased infarct size and ameliorated sympathetic activation during the late reperfusion phase. Preconditioning decreased infarct size by a further 35% ( P = .0017), but only a marginal decrease (by 18%, P = .075) was noted after postconditioning. Preconditioning decreased arrhythmias during ischemia and early reperfusion, whereas postconditioning almost abolished them during the entire reperfusion period. No differences were noted in MAPs or in the magnitude of sympathetic activation between the 2 interventions. Compared to postconditioning, preconditioning affords more powerful cytoprotection, but both interventions exert antiarrhythmic actions. In the latter, these are mainly evident during the ischemic phase and continue during early reperfusion. Postconditioning markedly decreases reperfusion arrhythmias during a prolonged observation period. The mechanisms underlying the antiarrhythmic effects of pre- and postconditioning are likely different but remain elusive.
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Affiliation(s)
- Theofilos M. Kolettis
- Medical School, University of Ioannina, Ioannina, Greece
- Cardiovascular Research Institute, Ioannina and Athens, Greece
| | - Agapi D. Vilaeti
- Cardiovascular Research Institute, Ioannina and Athens, Greece
- Department of Cardiology, Medical School, University of Ioannina, Ioannina, Greece
| | - Dimitrios G. Tsalikakis
- Department of Engineering Informatics and Telecommunications, Computational Cardiology and Modeling, University of Western Macedonia, Kozani, Greece
| | - Anastasia Zoga
- Second Department of Cardiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Mesele Valenti
- Cardiovascular Research Institute, Ioannina and Athens, Greece
| | - Alexandros T. Tzallas
- Department of Informatics & Telecommunications Technology, Technological Educational Institute of Epirus, Arta, Greece
| | - Apostolos Papalois
- Cardiovascular Research Institute, Ioannina and Athens, Greece
- ELPEN Research Laboratory, Pikermi, Athens, Greece
| | - Efstathios K. Iliodromitis
- Second Department of Cardiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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Endothelin-B Receptors and Left Ventricular Dysfunction after Regional versus Global Ischaemia-Reperfusion in Rat Hearts. Cardiol Res Pract 2012; 2012:986813. [PMID: 22844633 PMCID: PMC3403336 DOI: 10.1155/2012/986813] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 05/23/2012] [Accepted: 06/01/2012] [Indexed: 11/20/2022] Open
Abstract
Background. Endothelin-1 (ET-1) is implicated in left ventricular dysfunction after ischaemia-reperfusion. ETA and ETB receptors mediate diverse actions, but it is unknown whether these actions depend on ischaemia type and duration. We investigated the role of ETB receptors after four ischaemia-reperfusion protocols in isolated rat hearts.
Methods. Left ventricular haemodynamic variables were measured in the Langendorff-perfused model after 40- and 20-minute regional or global ischaemia, followed by 30-minute reperfusion. Wild-type (n = 39) and ETB-deficient (n = 41) rats were compared. Infarct size was measured using fluorescent microspheres after regional ischaemia-reperfusion.
Results. Left ventricular dysfunction was more prominent in ETB-deficient rats, particularly after regional ischaemia. Infarct size was smaller (P = 0.006) in wild-type (31.5 ± 4.4%) than ETB-deficient (45.0 ± 7.3%) rats after 40 minutes of regional ischaemia-reperfusion. Although the recovery of left ventricular function was poorer after 40-minute ischaemia-reperfusion, end-diastolic pressure in ETB-deficient rats was higher after 20 than after 40 minutes of regional ischaemia-reperfusion.
Conclusion. ETB receptors exert cytoprotective effects in the rat heart, mainly after regional ischaemia-reperfusion. Longer periods of ischaemia suppress the recovery of left ventricular function after reperfusion, but the role of ETB receptors may be more important during the early phases.
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Varnavas VC, Kontaras K, Glava C, Maniotis CD, Koutouzis M, Baltogiannis GG, Papalois A, Kolettis TM, Kyriakides ZS. Chronic skeletal muscle ischemia preserves coronary flow in the ischemic rat heart. Am J Physiol Heart Circ Physiol 2011; 301:H1229-35. [DOI: 10.1152/ajpheart.00232.2011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Chronic skeletal muscle ischemia confers cytoprotection to the ventricular myocardium during infarction, but the underlying mechanisms remain unclear. Although neovascularization in the left ventricular myocardium has been proposed as a possible mechanism, the functional capacity of such vessels has not been studied. We examined the effects of chronic limb ischemia on infarct size, coronary blood flow, and left ventricular function after ischemia-reperfusion. Hindlimb ischemia was induced in 65 Wistar rats by excision of the left femoral artery, whereas 65 rats were sham operated. After 4 wk, myocardial infarction was generated by permanent coronary artery ligation. Infarct size was measured 24 h postligation. Left ventricular function was evaluated in isolated hearts after ischemia-reperfusion, 4 wk after limb ischemia. Neovascularization was assessed by immunohistochemistry, and coronary flow was measured under maximum vasodilatation at different perfusion pressures before and after coronary ligation. Infarct size was smaller after limb ischemia compared with controls (24.4 ± 8.1% vs. 46.2 ± 9.5% of the ventricle and 47.6 ± 8.7% vs. 80.1 ± 9.3% of the ischemic area, respectively). Indexes of left ventricular function at the end of reperfusion (divided by baseline values) were improved after limb ischemia (developed pressure: 0.68 ± 0.06 vs. 0.59 ± 0.05, P = 0.008; maximum +dP/d t: 0.70 ± 0.08 vs. 0.59 ± 0.04, P = 0.004; and maximum −dP/d t: 0.86 ± 0.14 vs. 0.72 ± 0.10, P = 0.041). Coronary vessel density was markedly higher ( P = 0.00021) in limb ischemic rats. In contrast to controls ( F = 5.65, P = 0.00182), where coronary flow decreased, it remained unchanged ( F = 1.36, P = 0.28) after ligation in limb ischemic rats. In conclusion, chronic hindlimb ischemia decreases infarct size and attenuates left ventricular dysfunction by increasing coronary collateral vessel density and blood flow.
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Affiliation(s)
- Varnavas C. Varnavas
- Department of Cardiology, Red Cross Hospital, Athens
- Cardiovascular Research Institute, Ioannina and Athens
| | - Konstantinos Kontaras
- Department of Cardiology, Red Cross Hospital, Athens
- Cardiovascular Research Institute, Ioannina and Athens
| | - Chryssoula Glava
- Cardiovascular Research Institute, Ioannina and Athens
- Department of Pathology, Medical School, Athens University, Athens
| | - Christos D. Maniotis
- Department of Cardiology, Red Cross Hospital, Athens
- Cardiovascular Research Institute, Ioannina and Athens
| | - Michael Koutouzis
- Department of Cardiology, Red Cross Hospital, Athens
- Cardiovascular Research Institute, Ioannina and Athens
| | | | - Apostolos Papalois
- Cardiovascular Research Institute, Ioannina and Athens
- ELPEN Experimental Laboratory, Athens, Greece
| | - Theofilos M. Kolettis
- Cardiovascular Research Institute, Ioannina and Athens
- Department of Cardiology, University of Ioannina, Ioannina; and
| | - Zenon S. Kyriakides
- Department of Cardiology, Red Cross Hospital, Athens
- Cardiovascular Research Institute, Ioannina and Athens
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Oikonomidis DL, Tsalikakis DG, Baltogiannis GG, Tzallas AT, Xourgia X, Agelaki MG, Megalou AJ, Fotopoulos A, Papalois A, Kyriakides ZS, Kolettis TM. Endothelin-B receptors and ventricular arrhythmogenesis in the rat model of acute myocardial infarction. Basic Res Cardiol 2009; 105:235-45. [DOI: 10.1007/s00395-009-0066-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 09/10/2009] [Accepted: 09/21/2009] [Indexed: 01/01/2023]
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Elaiopoulos DA, Kolettis TM. Antiarrhythmic actions of growth hormone during acute myocardial infarction. J Electrocardiol 2008; 42:298-9. [PMID: 19100564 DOI: 10.1016/j.jelectrocard.2008.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Indexed: 10/21/2022]
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