1
|
Lieder HR, Tsoumani M, Andreadou I, Schrör K, Heusch G, Kleinbongard P. Platelet-Mediated Transfer of Cardioprotection by Remote Ischemic Conditioning and Its Abrogation by Aspirin But Not by Ticagrelor. Cardiovasc Drugs Ther 2023; 37:865-876. [PMID: 35595877 PMCID: PMC10517043 DOI: 10.1007/s10557-022-07345-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/30/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE The role of platelets during myocardial ischemia/reperfusion (I/R) is ambivalent. They contribute to injury but also to cardioprotection. Repeated blood flow restriction and reperfusion in a tissue/organ remote from the heart (remote ischemic conditioning, RIC) reduce myocardial I/R injury and attenuate platelet activation. Whether or not platelets mediate RIC's cardioprotective signal is currently unclear. METHODS AND RESULTS Venous blood from healthy volunteers (without or with pretreatment of 500/1000 mg aspirin or 180 mg ticagrelor orally, 2-3 h before the study, n = 18 each) was collected before and after RIC (3 × 5 min blood pressure cuff inflation at 200 mmHg on the left upper arm/5 min deflation). Washed platelets were isolated. Platelet-poor plasma was used to prepare plasma-dialysates. Platelets (25 × 103/µL) or plasma-dialysates (1:10) prepared before and after RIC from untreated versus aspirin- or ticagrelor-pretreated volunteers, respectively, were infused into isolated buffer-perfused rat hearts. Hearts were subjected to global 30 min/120 min I/R. Infarct size was stained. Infarct size was less with infusion of platelets/plasma-dialysate after RIC (18 ± 7%/23 ± 9% of ventricular mass) than with platelets/plasma-dialysate before RIC (34 ± 7%/33 ± 8%). Aspirin pretreatment abrogated the transfer of RIC's cardioprotection by platelets (after/before RIC, 34 ± 7%/33 ± 7%) but only attenuated that by plasma-dialysate (after/before RIC, 26 ± 8%/32 ± 5%). Ticagrelor pretreatment induced an in vivo formation of cardioprotective factor(s) per se (platelets/plasma-dialysate before RIC, 26 ± 7%/26 ± 7%) but did not impact on RIC's cardioprotection by platelets/plasma-dialysate (20 ± 7%/21 ± 5%). CONCLUSION Platelets serve as carriers for RIC's cardioprotective signal through an aspirin-sensitive and thus cyclooxygenase-dependent mechanism. The P2Y12 inhibitor ticagrelor per se induces a humoral cardioprotective signal.
Collapse
Affiliation(s)
- Helmut Raphael Lieder
- Institute for Pathophysiology, West German Heart and Vascular Centre, University of Essen Medical School, Essen, Germany
| | - Maria Tsoumani
- Laboratory of Pharmacology, National and Kapodistrian University of Athens, Athens, Greece
| | - Ioanna Andreadou
- Laboratory of Pharmacology, National and Kapodistrian University of Athens, Athens, Greece
| | - Karsten Schrör
- Department of Pharmacology and Clinical Pharmacology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Gerd Heusch
- Institute for Pathophysiology, West German Heart and Vascular Centre, University of Essen Medical School, Essen, Germany
| | - Petra Kleinbongard
- Institute for Pathophysiology, West German Heart and Vascular Centre, University of Essen Medical School, Essen, Germany.
| |
Collapse
|
2
|
Dolkart O, E A, S S, S M, P G, Aa W. Temporal determination of lung NO system and COX-2 upregulation following ischemia-reperfusion injury. Exp Lung Res 2013; 40:22-9. [PMID: 24354410 DOI: 10.3109/01902148.2013.858196] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Pulmonary ischemia-reperfusion (IR) is a biopathological event detectable in several clinical conditions, including lung transplantation, cardiopulmonary bypass, resuscitation, and pulmonary embolism. The understanding behind the activation of various inflammatory mediators regulating the apoptotic pathways remains largely unknown. We investigated the temporal expression of endothelial nitric oxide (eNOS), inducible (iNOS), and cyclooxygenase-2 (COX-2) proteins following lung-IR injury. METHODS Lung IR was induced in anesthetized rats. One hour ischemia was performed by clamping the left hilum. eNOS, iNOS, and COX-2 levels in the bronchoalveolar lavage (BAL) were measured at different time points after restoring lung perfusion in conjunction with histological changes and cellular apoptosis. RESULTS BAL-eNOS levels were increased as early as 3 hours post IR, attaining the highest values (5.5 U/mL) at 3 hours, compared to non-IR values (2.8 U/mL). BAL-iNOS increased at 3-hour post-IR (3 U/mL). iNOS reached the highest levels at 24 hours (4.5 U/mL) as compared to nonischemic lungs (1.8 U/mL). COX-2 peaked at 12 hours (.025 U/mL) compared to 3, 24, and 48 hours. Highest apoptotic rates were detected at 12 and 48 hours following IR. CONCLUSIONS The time-associated involvement of eNOS, iNOS, and COX-2 enzymes during the evolution of IR injury may point to an early reaction of the NOSs system versus the COX-2. Similar patterns of enzymatic activity were previously shown in the context of lung IR injury. This temporal activation may indicate an involvement of eNOS in an early reparative response, and possibly the late-pathological response, mediated by the coinduction of iNOS-COX-2.
Collapse
Affiliation(s)
- Oleg Dolkart
- 1Pre-Clinical Research Laboratory & Post-Anesthesia Care Unit and
| | | | | | | | | | | |
Collapse
|
3
|
Guo Y, Tukaye DN, Wu WJ, Zhu X, Book M, Tan W, Jones SP, Rokosh G, Narumiya S, Li Q, Bolli R. The COX-2/PGI2 receptor axis plays an obligatory role in mediating the cardioprotection conferred by the late phase of ischemic preconditioning. PLoS One 2012; 7:e41178. [PMID: 22844439 PMCID: PMC3402528 DOI: 10.1371/journal.pone.0041178] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 06/18/2012] [Indexed: 01/15/2023] Open
Abstract
Background Pharmacologic studies with cyclooxygenase-2 (COX-2) inhibitors suggest that the late phase of ischemic preconditioning (PC) is mediated by COX-2. However, nonspecific effects of COX-2 inhibitors cannot be ruled out, and the selectivity of these inhibitors for COX-2 vs. COX-1 is only relative. Furthermore, the specific prostaglandin (PG) receptors responsible for the salubrious actions of COX-2-derived prostanoids remain unclear. Objective To determine the role of COX-2 and prostacyclin receptor (IP) in late PC by gene deletion. Methods COX-2 knockout (KO) mice (COX-2−/−), prostacyclin receptor KO (IP−/−) mice, and respective wildtype (WT, COX-2+/+ and IP+/+) mice underwent sham surgery or PC with six 4-min coronary occlusion (O)/4-min R cycles 24 h before a 30-min O/24 h R. Results There were no significant differences in infarct size (IS) between non-preconditioned (non-PC) COX-2+/+, COX-2−/−, IP+/+, and IP−/− mice, indicating that neither COX-2 nor IP modulates IS in the absence of PC. When COX-2−/− or IP−/− mice were preconditioned, IS was not reduced, indicating that the protection of late PC was completely abrogated by deletion of either the COX-2 or the IP gene. Administration of the IP selective antagonist, RO3244794 to C57BL6/J (B6) mice 30 min prior to the 30-min O had no effect on IS. When B6 mice were preconditioned 24 h prior to the 30-min O, IS was markedly reduced; however, the protection of late PC was completely abrogated by pretreatment of RO3244794. Conclusions This is the first study to demonstrate that targeted disruption of the COX-2 gene completely abrogates the infarct-sparing effect of late PC, and that the IP, downstream of the COX-2/prostanoid pathway, is a key mediator of the late PC. These results provide unequivocal molecular genetic evidence for an essential role of the COX-2/PGI2 receptor axis in the cardioprotection afforded by the late PC.
Collapse
Affiliation(s)
- Yiru Guo
- Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, United States of America
| | - Deepali Nivas Tukaye
- Department of Internal Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Wen-Jian Wu
- Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, United States of America
| | - Xiaoping Zhu
- Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, United States of America
| | - Michael Book
- Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, United States of America
| | - Wei Tan
- Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, United States of America
| | - Steven P. Jones
- Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, United States of America
| | - Gregg Rokosh
- Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, United States of America
| | - Shuh Narumiya
- Department of Pharmacology, Kyoto University Faculty of Medicine, Kyoto, Japan
| | - Qianhong Li
- Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, United States of America
| | - Roberto Bolli
- Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, United States of America
- * E-mail:
| |
Collapse
|
4
|
Hatori N, Segawa D, Shimizu M, Bito H, Fukuda I, Yoshizu H, Tanaka S. Effects of coronary venous retroinfusion of lipo-prostaglandin E1on myocardial infarct size in pigs. Int J Angiol 2011. [DOI: 10.1007/bf01616178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
|
5
|
Meyer-Kirchrath J, Martin M, Schooss C, Jacoby C, Flögel U, Marzoll A, Fischer JW, Schrader J, Schrör K, Hohlfeld T. Overexpression of prostaglandin EP3 receptors activates calcineurin and promotes hypertrophy in the murine heart. Cardiovasc Res 2008; 81:310-8. [PMID: 19019835 DOI: 10.1093/cvr/cvn312] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Prostaglandin E(2) (PGE(2)) has been shown to mediate anti-ischaemic effects and cardiomyocyte hypertrophy and there is evidence for an involvement of the prostaglandin EP(3)-receptor subtype. This study focuses on the EP(3)-mediated hypertrophic action and investigates intracellular signalling pathways of the EP(3)-receptor subtype in the murine heart. METHODS AND RESULTS Cardiac function was analyzed in vivo by magnetic resonance imaging (MRI) in transgenic (tg) mice with cardio-specific overexpression of the EP(3) receptor in comparison with wild-type (wt) mice. Left ventricular (LV) function was determined in isolated perfused hearts subjected to 60 min of zero-flow ischaemia and 45 min of reperfusion. Calcineurin activity and nuclear activity of nuclear factor of activated T-cells (NFAT) were determined by a modified malachite green assay and ELISA, respectively. Extracellular matrix compounds were analyzed by RT-PCR and histology. MRI indicated a significant increase in end-diastolic and end-systolic volume in tg hearts. LV ejection fraction was severely decreased in tg hearts while the relative LV mass was significantly increased. In Langendorff perfused hearts, EP(3)-receptor overexpression resulted in a marked blunting of the ischaemia-induced increase in LV end-diastolic pressure and creatine kinase release. Analysis of EP(3)-receptor-mediated signalling revealed significantly increased calcineurin activity and nuclear activity of NFAT in tg hearts. Moreover, elevated mRNA levels of collagen types I and III as well as the collagen-binding proteoglycans biglycan and decorin were detected in tg hearts. CONCLUSION EP(3)-receptor-mediated signalling results in a significant anti-ischaemic action and activation of the pro-hypertrophic calcineurin signalling pathway, suggesting the involvement of the EP(3) subtype in both PGE(2)-mediated cardioprotection as well as cardiac hypertrophy.
Collapse
Affiliation(s)
- Jutta Meyer-Kirchrath
- Institut für Pharmakologie und Klinische Pharmakologie, Universitätsklinikum, Heinrich-Heine-Universität, Moorenstr. 5, D-40225 Düsseldorf, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Hishikari K, Suzuki JI, Ogawa M, Isobe K, Takahashi T, Onishi M, Takayama K, Isobe M. Pharmacological activation of the prostaglandin E2 receptor EP4 improves cardiac function after myocardial ischaemia/reperfusion injury. Cardiovasc Res 2008; 81:123-32. [PMID: 18805784 DOI: 10.1093/cvr/cvn254] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Increased expression of several subtypes of prostaglandin E(2) receptors (EP1-4) has recently been described in clinical and experimental myocardial ischaemia/reperfusion (I/R) injury. However, their pathophysiological significance in I/R remains obscure. Thus, we determined whether the activation of the prostanoid receptor, EP4, suppresses myocardial I/R injury. METHODS AND RESULTS To analyse the role of EP4, we administered an EP4 selective agonist (EP4RAG, 1 or 3 mg/kg) or vehicle to rats with myocardial I/R injury. After 7 days of reperfusion, I/R rats exhibited left ventricular (LV) dilatation and contractile dysfunction with myocyte hypertrophy and interstitial fibrosis. EP4RAG significantly reduced infarction area/ischaemic myocardium (72.4 +/- 0.7 vs. 23.3 +/- 0.6%; P < 0.05) and improved LV contraction and dilatation compared with that of the vehicle. EP4RAG also attenuated the recruitment of inflammatory cells, especially macrophages, and interstitial fibrosis in hearts. Monocyte chemoattractant protein (MCP)-1 and other cytokines were increased in both non-ischaemic (area not at risk, ANAR) and ischaemic (area at risk, AAR) myocardium; however, western blot analysis and RNase protection assay showed that EP4RAG suppressed these changes. Gelatin zymography revealed EP4RAG significantly reduced matrix metalloproteinase-2 and -9 activities in both ANAR and AAR. Chemoattractant assay demonstrated that EP4RAG suppressed the migration of cytokine-stimulated macrophages and decreased the level of MCP-1 production in the supernatant (587.3 +/- 55.3 vs. 171.5 +/- 47.5 pg/mL; P < 0.05). CONCLUSION The data suggest that the EP4 agonist is effective for attenuation of I/R injury by suppressing MCP-1 and the infiltration of inflammatory cells, especially macrophages.
Collapse
Affiliation(s)
- Keiichi Hishikari
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Lozano H, Wu D, Bassuk J, Aria J, Kurlansky P, Lamas GA, Adams JA. The effects of prostaglandin inhibition on whole-body ischemia-reperfusion in swine. Am J Emerg Med 2008; 26:45-53. [DOI: 10.1016/j.ajem.2007.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Accepted: 10/04/2007] [Indexed: 12/24/2022] Open
|
8
|
Miyahara Y, Ohnishi S, Obata H, Ishino K, Sano S, Mori H, Kangawa K, Kitamura S, Nagaya N. Beraprost sodium enhances neovascularization in ischemic myocardium by mobilizing bone marrow cells in rats. Biochem Biophys Res Commun 2006; 349:1242-9. [PMID: 16978584 DOI: 10.1016/j.bbrc.2006.08.178] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2006] [Accepted: 08/28/2006] [Indexed: 11/22/2022]
Abstract
Beraprost sodium, an orally active prostacyclin analogue, has vasoprotective effects such as vasodilation and antiplatelet activities. We investigated the therapeutic potential of beraprost for myocardial ischemia. Immediately after coronary ligation of Sprague-Dawley rats, beraprost (200 microg/kg/day) or saline was subcutaneously administered for 28 days. Four weeks after coronary ligation, administration of beraprost increased capillary density in ischemic myocardium, decreased infarct size, and improved cardiac function in rats with myocardial infarction. Beraprost markedly increased the number of CD34-positive cells and c-kit-positive cells in plasma. Also, four weeks after coronary ligation of chimeric rats with GFP-expressing bone marrow, bone marrow-derived cells were incorporated into the infarcted region and its border zone. Treatment with beraprost increased the number of GFP/von Willebrand factor-double-positive cells in the ischemic myocardium. These results suggest that beraprost has beneficial effects on ischemic myocardium partly by its ability to enhance neovascularization in ischemic myocardium by mobilizing bone marrow cells.
Collapse
Affiliation(s)
- Yoshinori Miyahara
- Department of Regenerative Medicine and Tissue Engineering, National Cardiovascular Center Research Institute, Osaka, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
|
10
|
Jiang X, Shi E, Nakajima Y, Sato S, Ohno K, Yue H. Cyclooxygenase-1 Mediates the Final Stage of Morphine-Induced Delayed Cardioprotection in Concert With Cyclooxygenase-2. J Am Coll Cardiol 2005; 45:1707-15. [PMID: 15893191 DOI: 10.1016/j.jacc.2005.02.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Revised: 01/21/2005] [Accepted: 02/01/2005] [Indexed: 11/22/2022]
Abstract
OBJECTIVES We sought to investigate the time course of morphine-induced delayed cardioprotection and examine the role of cyclooxygenase (COX) in this cardioprotective effect. BACKGROUND Cyclooxygenase-2 has been shown to be essential for the delayed cardioprotection induced by ischemic preconditioning and delta-opioid agonists. METHODS Male mice were subjected to 45 min of coronary artery occlusion followed by 120 min of reperfusion. Expressions of COX-2 and COX-1 were assessed by Western blotting, and the myocardial prostaglandin (PG)E2 and 6-keto-PGF(1-alpha) contents were measured using enzyme immunoassays. RESULTS A powerful infarct-sparing effect appeared 24 and 48 h after morphine preconditioning and faded after 72 h. After 24 h, the anti-infarct effect was associated with enhanced myocardial levels of COX-2, PGE2, and 6-keto-PGF(1-alpha), and no changes in COX-1 protein levels were found. Cardioprotection and increases in PGE2 and 6-keto-PGF(1-alpha) were completely abolished by the COX-2-selective inhibitor NS-398 and the non-selective COX inhibitor indomethacin, whereas the COX-1-selective inhibitor SC-560 had no effect. After 48 h, up-regulation of myocardial PGE2 and 6-keto-PGF(1-alpha) was also observed, and COX-1 expression was enhanced markedly, but only a slight increase in COX-2 expression was apparent. Cardioprotection and the increases in PGE2 and 6-keto-PGF(1-alpha) 48 h after morphine administration were abrogated only by indomethacin, and not by SC-560 or NS-398. CONCLUSIONS Morphine confers delayed cardioprotection via a COX-dependent pathway; COX-2 is essential for the cardioprotection observed in the initial stage (24 h), whereas, in the final stage (48 h), cardioprotection is mediated by COX-1 in concert with COX-2.
Collapse
Affiliation(s)
- Xiaojing Jiang
- Department of Anesthesiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | | | | | | | | | | |
Collapse
|
11
|
Shinmura K, Tamaki K, Sato T, Ishida H, Bolli R. Prostacyclin attenuates oxidative damage of myocytes by opening mitochondrial ATP-sensitive K+ channels via the EP3 receptor. Am J Physiol Heart Circ Physiol 2004; 288:H2093-101. [PMID: 15604124 DOI: 10.1152/ajpheart.01003.2004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Prostacyclin (PGI2) and the PGE family alleviate myocardial ischemia-reperfusion injury and limit oxidative damage. The cardioprotective effects of PGI2 have been traditionally ascribed to activation of IP receptors. Recent advances in prostanoid research have revealed that PGI2 can bind not only to IP, but also to EP, receptors, suggesting cross talk between PGI2 and PGEs. The mechanism(s) whereby PGI2 protects myocytes from oxidative damage and the specific receptors involved remain unknown. Thus fresh isolated adult rat myocytes were exposed to 200 microM H2O2 with or without carbaprostacyclin (cPGI2), IP-selective agonists, and ONO-AE-248 (an EP3-selective agonist). Cell viability was assessed by trypan blue exclusion after 30 min of H2O2 superfusion. cPGI2 and ONO-AE-248 significantly improved cell survival during H2O2 superfusion; IP-selective agonists did not. The protective effect of cPGI2 and ONO-AE-248 was completely abrogated by pretreatment with 5-hydroxydecanoate or glibenclamide. In the second series of experiments, the mitochondrial ATP-sensitive K+ (K(ATP)) channel opener diazoxide (Dx) reversibly oxidized flavoproteins in control myocytes. Exposure to prostanoid analogs alone had no effect on flavoprotein fluorescence. A second application of Dx in the presence of cPGI2 or ONO-AE-248 significantly increased flavoprotein fluorescence compared with Dx alone, but IP-selective agonists did not. This study demonstrates that PGI2 analogs protect cardiac myocytes from oxidative stress mainly via activation of EP3. The data also indicate that activation of EP3 receptors primes the opening of mitochondrial K(ATP) channels and that this mechanism is essential for EP3-dependent protection.
Collapse
Affiliation(s)
- Ken Shinmura
- Department of Internal Medicine, Keio University School of Medicine, Shinanomachi, Tokyo, Japan.
| | | | | | | | | |
Collapse
|
12
|
Nanas JN, Tsolakis E, Terrovitis JV, Eleftheriou A, Drakos SG, Dalianis A, Charitos CE. Moderate Systemic Hypotension During Reperfusion Reduces the Coronary Blood Flow and Increases the Size of Myocardial Infarction in Pigs. Chest 2004; 125:1492-9. [PMID: 15078763 DOI: 10.1378/chest.125.4.1492] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
STUDY OBJECTIVE s: To examine the effects of low arterial BP (ABP) during reperfusion on the extent of myocardial infarction and on coronary blood flow (CBF) in an occlusion/reperfusion experimental model. DESIGN Prospective, randomized animal study. SETTING University hospital. PARTICIPANTS Normal pigs that were anesthetized, intubated, and mechanically ventilated. INTERVENTIONS Twenty-seven open-chest pigs underwent occlusion of the mid left anterior descending (LAD) coronary artery for 1 h followed by reperfusion for 2 h. During reperfusion, the animals were randomly assigned to either continuous infusion of nitroglycerin in therapeutic doses and fluid infusion at rates to maintain a mean ABP >or= 80 mm Hg (group 1, n = 13), or continuous nitroglycerin infusion at rates to maintain a mean ABP between 60 mm Hg and 75 mm Hg (group 2, n = 14). MEASUREMENTS AND RESULTS The hemodynamics and the coronary ABP distal to the occlusion were recorded throughout the experiment. In addition, the LAD CBF and peak hyperemia CBF before occlusion and during reperfusion periods were measured by transit-time flowmetry. At the end of the experiment, the infarcted left ventricular myocardial size was measured. There were no significant hemodynamic differences, including the distal coronary arterial pressure, between the two groups before or during the LAD artery occlusion period. During reperfusion, mean ABP was 90 +/- 3 mm Hg in group 1 vs 69 +/- 3 mm Hg in group 2 (p < 0.001). In group 1, the infarcted myocardium represented 50.3 +/- 4.3% of the myocardium at risk, vs 69.4 +/- 7.2% in group 2 (p < 0.001). During reperfusion, CBF and peak hyperemia CBF were significantly higher in group 1 than in group 2. CONCLUSIONS Low ABP during reperfusion increases the size of myocardial infarction and decreases CBF.
Collapse
Affiliation(s)
- John N Nanas
- University of Athens School of Medicine, Department of Clinical Therapeutics, Alexandra Hospital, Athens, Greece.
| | | | | | | | | | | | | |
Collapse
|
13
|
Shinmura K, Nagai M, Tamaki K, Tani M, Bolli R. COX-2-derived prostacyclin mediates opioid-induced late phase of preconditioning in isolated rat hearts. Am J Physiol Heart Circ Physiol 2002; 283:H2534-43. [PMID: 12388283 DOI: 10.1152/ajpheart.00209.2002] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Opioids confer biphasic (early and late) cardioprotection against myocardial infarction by opening mitochondrial ATP-sensitive K(+) channels. It is unknown whether cyclooxygenase-2 (COX-2), which mediates ischemia-induced late preconditioning, also mediates opioid-induced cardioprotection. Isolated perfused rat hearts were subjected to 20 min of global ischemia followed by 20 min of reperfusion. BW-373U86 (BW), a delta-opioid receptor agonist, was administered 1, 12, or 24 h before death. Recovery of left ventricular developed pressure (LVDP) after ischemia-reperfusion improved when BW was administered 1 or 24 h before ischemia (control: 57 +/- 8, BW 1 h: 75 +/- 5, BW 24 h: 85 +/- 6%) but not when it was administered 12 h before (60 +/- 5%). Levels of 6-keto-PGF(1alpha) (a stable metabolite of PGI(2)) in coronary effluent after 20 min of reperfusion were higher with 24-h BW pretreatment than in controls (1,053 +/- 92 vs. 724 +/- 81 pg/ml), whereas 6-keto-PGF(1alpha) levels at baseline did not differ. Administration of a selective COX-2 inhibitor, NS-398, abolished the late phase of cardioprotection (recovery of LVDP, 53 +/- 8%) and attenuated the increase in PGI(2) (706 +/- 138 pg/ml) but did not block the early phase of cardioprotection. The selective COX-1 inhibitor SC-560 did not affect either phase of protection. Western immunoblotting revealed upregulation of PGI(2) synthase protein 24 h after BW administration without changes in COX-1 and COX-2 protein levels. In conclusion, the late (but not the early) phase of delta-opioid receptor-induced preconditioning is mediated by COX-2. A functional coupling between COX-2 and upregulated PGI(2) synthase appears to underlie this cardioprotective phenomenon in the rat.
Collapse
Affiliation(s)
- Ken Shinmura
- Department of Internal Medicine, Keio University School of Medicine, Tokyo 160 - 8582, Japan.
| | | | | | | | | |
Collapse
|
14
|
Bolli R, Shinmura K, Tang XL, Kodani E, Xuan YT, Guo Y, Dawn B. Discovery of a new function of cyclooxygenase (COX)-2: COX-2 is a cardioprotective protein that alleviates ischemia/reperfusion injury and mediates the late phase of preconditioning. Cardiovasc Res 2002; 55:506-19. [PMID: 12160947 PMCID: PMC3242376 DOI: 10.1016/s0008-6363(02)00414-5] [Citation(s) in RCA: 194] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
More than 10 years after its discovery, the function of cyclooxygenase-2 (COX-2) in the cardiovascular system remains largely an enigma. Many scholars have assumed that the allegedly detrimental effects of COX-2 in other systems (e.g. proinflammatory actions and tumorigenesis) signify a detrimental role of this protein in cardiovascular homeostasis as well. This view, however, is ill-founded. Recent studies have demonstrated that ischemic preconditioning (PC) upregulates the expression and activity of COX-2 in the heart, and that this increase in COX-2 activity mediates the protective effects of the late phase of PC against both myocardial stunning and myocardial infarction. An obligatory role of COX-2 has been observed in the setting of late PC induced not only by ischemia but also by delta-opioid agonists and physical exercise, supporting the view that the recruitment of this protein is a central mechanism whereby the heart protects itself from ischemia. The beneficial actions of COX-2 appear to be mediated by the synthesis of PGE(2) and/or PGI(2). Since inhibition of iNOS in preconditioned myocardium blocks COX-2 activity whereas inhibition of COX-2 does not affect iNOS activity, COX-2 appears to be downstream of iNOS in the protective pathway of late PC. The results of these studies challenge the widely accepted paradigm that views COX-2 activity as detrimental. The discovery that COX-2 plays an indispensable role in the anti-stunning and anti-infarct effects of late PC demonstrates that the recruitment of this protein is a fundamental mechanism whereby the heart adapts to stress, thereby revealing a novel, hitherto unappreciated cardioprotective function of COX-2. From a practical standpoint, the recognition that COX-2 is an obligatory co-mediator (together with iNOS) of the protection afforded by late PC has implications for the clinical use of COX-2 selective inhibitors as well as nonselective COX inhibitors. For example, the possibility that inhibition of COX-2 activity may augment myocardial cell death by obliterating the innate defensive response of the heart against ischemia/reperfusion injury needs to be considered and is the object of much current debate. Furthermore, the concept that the COX-2 byproducts, PGE(2) and/or PGI(2), play a necessary role in late PC provides a basis for novel therapeutic strategies designed to enhance the biosynthesis of these cytoprotective prostanoids in the ischemic myocardium. From a conceptual standpoint, the COX-2 hypothesis of late PC expands our understanding of the function of this enzyme in the cardiovascular system and impels a critical reassessment of current thinking regarding the biologic significance of COX-2.
Collapse
Affiliation(s)
- Roberto Bolli
- Division of Cardiology, University of Louisville, 550 South Jackson St., KY 40202, USA.
| | | | | | | | | | | | | |
Collapse
|
15
|
Thiemermann C, Zacharowski K. Selective activation of E-type prostanoid(3)-receptors reduces myocardial infarct size. A novel insight into the cardioprotective effects of prostaglandins. Pharmacol Ther 2000; 87:61-7. [PMID: 10924742 DOI: 10.1016/s0163-7258(00)00069-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Prostaglandins (PGs) and other eicosanoids are members of a large family of lipid mediators (autacoids). In 1978, Lefer and colleagues (Science 200, 52-55 [1978]) reported that prostacyclin reduces the myocardial tissue injury caused by coronary artery occlusion and reperfusion in the cat. Since this discovery, more than 50 papers have reported on the cardioprotective effects of vasodilator PGs, including prostacyclin. The cardioprotective effects of PGs are due in part to (1) a reduction in afterload, (2) an increase in coronary blood flow, (3) the inhibition of platelet function, and (4) the inhibition of the activation and extravasation of polymorphonuclear granulocytes. All of these effects are secondary to the activation of EP (E-type prostanoid)(2)-receptors, which activate G(s)-protein and, hence, adenylate cyclase. In addition, the protection of organs such as the heart by PGs has been attributed to a cytoprotective effect of these agents, the mechanism of which is largely unknown. We recently have discovered that certain E-type PGs, which do not activate EP(2)-receptors, also reduce myocardial infarct size, without causing a fall in blood pressure (EP(2)-receptor-mediated effects). Having provided a brief introduction into the role of eicosanoids in ischaemia-reperfusion injury of the heart, this review focuses on the recent discovery that selective agonists of EP(3)-receptors reduce myocardial infarct size, without causing haemodynamic side effects. The mechanisms of the cardioprotective effects of these agents are discussed, as are the therapeutic implications.
Collapse
Affiliation(s)
- C Thiemermann
- William Harvey Research Institute, Department of Experimental Medicine and Nephrology, St. Bartholomew's and the Royal London School of Medicine and Dentistry, Charterhouse Square, EC1M 6BQ, London, UK.
| | | |
Collapse
|
16
|
Yamamoto T, Habuchi Y, Tanaka H, Suto F, Morikawa J, Kashima K, Yoshimura M. EP receptor-mediated inhibition by prostaglandin E(1) of cardiac L-type Ca(2+) current of rabbits. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:H1369-74. [PMID: 10516171 DOI: 10.1152/ajpheart.1999.277.4.h1369] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Prostaglandin E(1) (PGE(1)) has cardioprotective effects on the ischemic-reperfused heart. To clarify the mechanisms underlying the protective action of PGE(1) on myocardium, we examined the effect of PGE(1) on the L-type Ca(2+) current (I(Ca)) using single atrial cells from rabbits. PGE(1) did not show a significant effect on basal I(Ca) but inhibited the I(Ca) prestimulated by isoproterenol (Iso, 30 nM). This inhibition was concentration dependent (EC(50) = 0.027 microM). Both sulprostone, a specific PGE receptor subtype (EP(1) and EP(3)) agonist, and 11-deoxy-PGE(1), an EP(3) agonist, inhibited the Iso-stimulated I(Ca), similar to PGE(1). Pretreatment with pertussis toxin (PTX) abolished the PGE(1) inhibition of I(Ca). Both the application of forskolin plus IBMX and intracellular dialysis with 8-bromoadenosine 3',5'-cyclic monophosphate eliminated the effect of PGE(1). PGE(1) did not show any further inhibition of I(Ca) when the effect of Iso was almost fully antagonized by acetylcholine. Methylene blue (guanylate cyclase inhibitor), KT-5823 (cGMP-dependent protein kinase inhibitor), and erythro-9-(2-hydroxy-3-nonyl)adenine (type II phosphodiesterase inhibitor) did not significantly change the inhibitory effect of PGE(1). These findings suggest that 1) PGE(1) inhibits Iso-stimulated I(Ca) by binding to the EP(3) receptor and 2) the PTX-sensitive and cAMP-dependent pathway is involved in the PGE(1) inhibition of I(Ca), but the nitric oxide-cGMP-dependent pathway is not. The PGE(1)-induced antiadrenergic effect shown in this study may contribute to the PGE(1) protection of myocardium against ischemia.
Collapse
Affiliation(s)
- T Yamamoto
- Department of Laboratory Medicine, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-0841, Japan
| | | | | | | | | | | | | |
Collapse
|
17
|
Yamamoto T, Cohen AM, Kakar NR, Yamamoto M, Johnson PE, Cho YK, Bing RJ. Production of prostanoids and nitric oxide by infarcted heart in situ and the effect of aspirin. Biochem Biophys Res Commun 1999; 257:488-93. [PMID: 10198239 DOI: 10.1006/bbrc.1999.0488] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The production of prostacyclin (PGI2) and thromboxane A2 (TXA2) in infarcted and noninfarcted portions of the rabbit heart was studied prior to and following administration of acetylsalicylic acid (aspirin). Aspirin was administered intravenously (iv) as water-soluble Aspisol, d-lysinmono (acetylsalicylate) (Bayer, Leverkusen, Germany) into an ear vein. A branch of the left circumflex coronary artery was ligated. The animals were divided into three groups. The first group received 150 mg/kg/day of aspirin (75 mg/kg of aspirin every 12 h, n = 10). The first administration of aspirin was 1 h after ligation of the coronary artery and the last injection was 1 h before euthanasia. The second group received 5 mg/kg/day of aspirin (every 24 h, n = 10). A separate group of rabbits not receiving aspirin served as controls (n = 12). Two days following onset of ischemia, inducible form of nitric oxide synthase (iNOS) was measured in heart muscle and the oxidation products of nitric oxide (nitrite, NO-2 plus nitrate, NO-3: their sum referred to as NOx) were determined in arterial and coronary venous blood. Concentrations of both PGI2 and TXA2 were elevated in the infarcted portions of the heart compared to the noninfarcted regions. Formation of prostanoids was accompanied by increased activation of iNOS. Both doses of aspirin diminished the concentrations of PGI2 and TXA2 in infarcted heart muscle; in contrast, small doses of aspirin failed to influence myocardial iNOS activity. Apparently small doses of aspirin changed the relationship of iNOS to cyclooxygenase (COX). Coronary arterial-venous difference of NOx and myocardial iNOS activity showed parallel increases. Diminution of prostacyclin by aspirin can damage gastric mucosa and interfere with vasodilatation. Since NO counters these deficiencies, a combination of aspirin with a nitric oxide donor may be advantageous.
Collapse
Affiliation(s)
- T Yamamoto
- Department of Experimental Cardiology, Huntington Medical Research Institutes, 99 North El Molino Avenue, Pasadena, California, 91101, USA
| | | | | | | | | | | | | |
Collapse
|
18
|
Zacharowski K, Olbrich A, Thiemermann C. Reduction of myocardial injury by the EP3 receptor agonist TEI-3356. Role of protein kinase C and of K(ATP)-channels. Eur J Pharmacol 1999; 367:33-9. [PMID: 10082262 DOI: 10.1016/s0014-2999(98)00963-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effects of the prostanoid EP3 receptor agonist TEI-3356 on either protein kinase C or ATP-sensitive (K(ATP)) K+ channels and on the infarct size caused by regional myocardial ischaemia and reperfusion in the rat were investigated. Male Wistar rats (n = 72) were subjected to 25 min occlusion of the left anterior descending coronary artery followed by 2 h of reperfusion. TEI-3356 (1 microg/kg/min i.v., n = 6) caused a significant reduction in infarct size from 60+/-3% (control, n = 8) to 38+/-3% of the area at risk. Pretreatment of rats with 5-hydroxydecanoate (5 mg/kg i.v., n = 6), a specific inhibitor of K(ATP)-channels, attenuated the cardioprotective effects of TEI-3356. The reduction in infarct size afforded by TEI-3356 was also abolished by the protein kinase C inhibitors staurosporine (1 microg/kg i.v., n = 6) and chelerythrine (0.7 mg/kg i.v., n = 5). Thus, TEI-3356 reduces myocardial infarct size in the rat by a mechanism(s) which involves the activation of protein kinase C and the opening of K(ATP)-channels.
Collapse
Affiliation(s)
- K Zacharowski
- The William Harvey Research Institute, St. Bartholomew's and The Royal London School of Medicine and Dentistry, UK
| | | | | |
Collapse
|
19
|
Zacharowski K, Olbrich A, Otto M, Hafner G, Thiemermann C. Effects of the prostanoid EP3-receptor agonists M&B 28767 and GR 63799X on infarct size caused by regional myocardial ischaemia in the anaesthetized rat. Br J Pharmacol 1999; 126:849-58. [PMID: 10193764 PMCID: PMC1571228 DOI: 10.1038/sj.bjp.0702348] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. This study investigates the effects of two agonists of the prostanoid EP3-receptor (M&B 28767 and GR 63799X) on the infarct size caused by regional myocardial ischaemia and reperfusion in the anaesthetized rat. 2. One hundred and sixty-seven, male Wistar rats were anaesthetized (thiopentone, 120 mg kg(-1) i.p.), ventilated (8-10 ml kg(-1), 70 strokes min(-1), inspiratory oxygen concentration: 30%; PEEP: 1-2 mmHg) and subjected to occlusion of the left anterior descending coronary artery (LAD, for 7.5, 15, 25, 35, 45 or 60 min) followed by reperfusion (2 h). Infarct size was determined by staining of viable myocardium with a tetrazolium stain (NBT), histological evaluation by light and electron microscopy and determination of the plasma levels of cardiac troponin T. 3. M&B 28767 (0.5 microg kg(-1) min(-1), i.v., n=7) or GR 63799X (3 microg kg(-1) min(-1), i.v., n=7) caused significant reductions in infarct size from 60+/-3% (25 min ischaemia and 2 h reperfusion; saline-control, n=8) to 39+/-6 and 38+/-4% of the area at risk, without causing a significant fall in blood pressure. Pretreatment of rats with 5-hydroxydecanoate (5-HD), an inhibitor of ATP-sensitive potassium channels, attenuated the cardioprotective effects of both EP3-receptor agonists. The reduction in infarct size afforded by M&B 28767 was also abolished by glibenclamide and the protein kinase C (PKC) inhibitors staurosporine and chelerythrine. 4. Thus, M&B 28767 and GR 63799X reduce myocardial infarct size in the rat by a mechanism(s) which involves the activation of PKC and the opening of ATP-sensitive potassium channels.
Collapse
Affiliation(s)
- K Zacharowski
- The William Harvey Research Institute, St. Bartholomew's and The Royal London School of Medicine and Dentistry, England, UK
| | | | | | | | | |
Collapse
|
20
|
Abstract
Prostaglandins (PGs) and thromboxanes are important modulators of platelet activation, and there is strong evidence to support the existence of distinct thromboxane, prostacyclin, PGD2 and PGE2 receptors on the platelet plasma membrane. In this review, each of these platelet prostanoid receptors is discussed in detail, with respect to their receptor pharmacology, molecular biology and signal transduction, and as to any therapeutic implications of the development of specific agonists and/or antagonists. In addition, it considers the possibility that there are separate vascular receptors for 8-epi PGF2 alpha, which are not present on the platelet.
Collapse
MESH Headings
- Blood Platelets/metabolism
- Humans
- Receptors, Epoprostenol
- Receptors, Immunologic
- Receptors, Prostaglandin/agonists
- Receptors, Prostaglandin/blood
- Receptors, Prostaglandin/genetics
- Receptors, Prostaglandin E/agonists
- Receptors, Prostaglandin E/blood
- Receptors, Prostaglandin E/genetics
- Receptors, Thromboxane/blood
- Receptors, Thromboxane/genetics
- Signal Transduction
Collapse
Affiliation(s)
- R A Armstrong
- Department of Dietetics & Nutrition, Queen Margaret College, Edinburgh, Scotland
| |
Collapse
|
21
|
Abstract
Experimental, epidemiologic and clinical studies have provided strong evidence that physical exercise has beneficial effects on multiple physiological variables affecting cardiovascular health (lipoprotein levels, rest blood pressure and heart rate, carbohydrate tolerance, neurohormonal activity). Regular exercise has been shown to slow the progression of cardiovascular disease and to reduce cardiovascular morbidity and mortality. More recently, exercise-induced increases in blood flow and shear stress have been observed to enhance vascular function and structure. By increasing the release of nitric oxide and prostacyclin, shear stress augments endothelium-dependent vasodilation and inhibits multiple processes involved in atherogenesis and restenosis. In this review we discuss the underlying mechanisms by which exercise-induced blood flow and shear stress exert their salutary effects on cardiovascular remodeling.
Collapse
Affiliation(s)
- J Niebauer
- Section of Vascular Medicine, Stanford University, California 94305-5246, USA
| | | |
Collapse
|
22
|
Feld S, Li G, Wu A, Felli P, Amirian J, Vaughn WK, Gornet T, Swenson C, Smalling RW. Reduction of canine infarct size by bolus intravenous administration of liposomal prostaglandin E1: comparison with control, placebo liposomes, and continuous intravenous infusion of prostaglandin E1. Am Heart J 1996; 132:747-57. [PMID: 8831361 DOI: 10.1016/s0002-8703(96)90306-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Prostaglandin E1 (PGE1) reduces experimental infarct size when administered by prolonged low-dose left atrial infusion during coronary occlusion. Liposomal delivery of PGE1 may enhance biologic activity and limit adverse hemodynamic effects. The purpose of this study was to test the hypothesis that intravenous bolus administration of liposomal PGE1 (TLC C-53, The Liposome Company, Princeton, N.J.) during coronary occlusion would result in myocardial salvage. We compared TLC C-53 (0.5 microgram/kg intravenous bolus at 10 and 100 min of occlusion of the left anterior descending coronary artery [LAD]), free PGE1 (0.1 microgram/kg/min infused 10 min after LAD occlusion until reperfusion), placebo liposomes, and control (n = 7 for each group) in an open-chest canine model of 2 hours of LAD occlusion and reperfusion. Infarct size as a percentage of risk area (mean +/- SD) in the control group (58.4% +/- 20.0%) was similar to that in animals given placebo liposomes (53.1% +/- 12.6%) but was significantly reduced in the groups given TLC C-53 (33.5% +/- 9.2%; p < 0.01) or free PGE1 (37.2% +/- 4.8%; p < 0.05) groups. Infarct salvage was significant (p < 0.05) for the TLC C-53-and PGE1-treated dogs compared with the control dogs, independent of collateral blood flow by analysis of covariance. Moreover, the ischemic-zone blood flow during reperfusion was significantly higher in the TLC C-53 group compared with the control group or the group receiving free PGE1. Neutrophil infiltration of ischemic myocardium was significantly inhibited by TLC C-53 as determined by myeloperoxidase assay. Unlike free PGE1, TLC C-53 did not cause significant tachycardia or hypotension during therapy. In conclusion, TLC C-53 administered intravenously during coronary occlusion significantly reduced infarct size, limited neutrophil infiltration, and improved myocardial blood flow during reperfusion without adverse hemodynamic consequences.
Collapse
Affiliation(s)
- S Feld
- Department of Internal Medicine, University of Texas Medical School at Houston 77030, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Hide EJ, Thiemermann C. Sulprostone-induced reduction of myocardial infarct size in the rabbit by activation of ATP-sensitive potassium channels. Br J Pharmacol 1996; 118:1409-14. [PMID: 8832065 PMCID: PMC1909684 DOI: 10.1111/j.1476-5381.1996.tb15553.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
1. This study examined whether (i) a 1 h pretreatment with or (ii) a continuous infusion of sulprostone reduces myocardial infarct size arising from coronary artery occlusion (60 min) and reperfusion (120 min) in the anaesthetized rabbit. In addition, we investigated whether the observed cardioprotective effect of this selective agonist of prostanoid EP1/EP3 receptors were due to the activation of ATP-sensitive potassium (KATP) channels. 2. In anaesthetized rabbits pretreated with vehicle (5% ethanol in 0.9% saline; 0.05 ml min-1, i.v.) infarct size (expressed as a percentage of the area at risk) after 60 min of coronary artery occlusion followed by 120 min of reperfusion was 59 +/- 4% (n = 10). Pretreatment of rabbits with sulprostone (1.0 microgram kg-1 min-1 for 1 h, discontinued immediately prior to coronary artery occlusion) did not reduce infarct size (60 +/- 4%; n = 4). In contrast, a continuous infusion of sulprostone (1.0 microgram kg-1 min-1) starting 10 min prior to the onset of LAL occlusion and continued throughout the experiment, significantly reduced infarct size (41 +/- 5%, n = 6) when compared to the respective vehicle-treated controls (57 +/- 4%, n = 10; P < 0.05). Sulprostone (pretreatment or continuous infusion) had no effect on any of the haemodynamic parameters measured. 3. The reduction in infarct size afforded by continuous infusion of sulprostone was abolished by pretreatment of rabbits with the KATP channel blocker 5-hydroxydecanoate (5-HD 5 micrograms kg-1; 63 +/- 4%; n = 6). When administered alone, 5-HD had no effect on infarct size when compared to control (52 +/- 6, n = 10). 4. We propose that a continuous infusion of the selective EP1/EP3 prostanoid receptor agonist, sulprostone, reduces infarct size in the anaesthetized rabbit by a mechanism that involves the opening of KATP channels.
Collapse
Affiliation(s)
- E J Hide
- William Harvey Research Institute, St. Bartholomew's Hospital Medical College, London
| | | |
Collapse
|
24
|
Feng J, Wu G, Tang S, Chahine R, Lamontagne D. Beneficial effects of iloprost cardioplegia in ischemic arrest in isolated working rat heart. Prostaglandins Leukot Essent Fatty Acids 1996; 54:279-83. [PMID: 8804125 DOI: 10.1016/s0952-3278(96)90059-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To determine whether the prostacyclin analog iloprost plays a beneficial role in crystalloid cardioplegia in isolated working rat hearts, 20 isolated rat hearts were studied after sustaining 90 min of cardioplegic arrest under hypothermia (20 degrees C). The findings indicated that thromboxane A2 (TXA2) levels in coronary effluent were increased during reperfusion. Iloprost (12 nm/l) inhibited the release of TXA2 and improved the recovery of cardiac hemodynamics after ischemia. These data demonstrated that cardiac-derived TXA2 appeared to mediate reperfusion injury after prolonged aortic clamp or cardiac transplantation and iloprost cardioplegic infusion resulted in the inhibition of release of cardiac-derived TXA2 and in a better preservation of cardiac function after ischemic arrest.
Collapse
Affiliation(s)
- J Feng
- Department of Physiology, Faculty of Medicine, Research Center of Sacre-Coeur Hospital, Montreal, Quebec, Canada
| | | | | | | | | |
Collapse
|
25
|
Robinson BL, Morita T, Fujita K, Chow M, Schaff HV, Morris JJ. Bypass conduit vessel wall biology substantially influences downstream myocardial contractile response to injury from ischemia and reperfusion. J Thorac Cardiovasc Surg 1996; 111:62-73. [PMID: 8551790 DOI: 10.1016/s0022-5223(96)70402-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Coronary vascular intraluminal release of endogenous endothelium-derived substances, such as prostacyclin, may affect downstream cardiac myocyte contractile function. With a "chronic" canine model of endothelialized and deendothelialized internal thoracic artery coronary grafts, we tested the hypothesis that higher basal release of endothelium-derived prostacyclin in internal thoracic artery bypass conduit effluent accelerates functional recovery of postischemic stunned myocardium in the intact circulation. Eleven dogs underwent left internal thoracic artery-left circumflex artery bypass, and the proximal circumflex artery was then ligated. Internal thoracic artery conduit endothelium was denuded by balloon catheter in five dogs before grafting and left intact in six dogs. After 7 days, awake dogs were studied to measure myocardial segment length in the circumflex region with ultrasonic dimension transducers, left ventricular pressure with micromanometers, and circumflex artery flow with an ultrasonic flow probe. Regional contractile function was quantified by the area beneath the linear preload recruitable stroke work relationship at baseline and at intervals after a 15-minute circumflex graft occlusion followed by 3 hours of reperfusion. Heart rate, left ventricular peak pressure, left ventricular end-diastolic pressure, left ventricular peak first derivative of pressure (dP/dt), and circumflex flow were similar (all p not significant) in endothelialized and nonendothelialized dogs during ischemia and reperfusion. Ischemia reduced the preload recruitable stroke work relationship to 44% +/- 35% of control values (p < 0.01) in endothelialized dogs and to 47% +/- 18% of control values in nonendothelialized dogs (p < 0.01) at 15 minutes of reperfusion, indicating a similar (p not significant) initial degree of injury. During 3 hours of reperfusion, the preload recruitable stroke work relationship returned to 51% +/- 17% of control values in endothelialized dogs but to only 35% +/- 20% of control values in nonendothelialized dogs (p < 0.02). Basal intraluminal release of endogenous prostanoids in excised internal thoracic artery conduits was subsequently quantified by ex vivo bioassay of vasoactive properties of conduit effluent on normal coronary artery smooth muscle. Endothelialized conduits induced greater smooth muscle relaxation than did nonendothelialized conduits (67% vs 23%), and this increased relaxation by endothelialized conduits was eliminated by indomethacin, a blocker of prostanoid synthesis. These data indicate that coronary bypass conduit endothelium-derived substances, such as prostacyclin, significantly influence downstream myocardial contractile response to ischemia and reperfusion, independent of alterations in coronary flow in the intact circulation.
Collapse
Affiliation(s)
- B L Robinson
- Division of Thoracic and Cardiovascular Surgery, Mayo Clinic and Foundation, Rochester, Minn 55905, USA
| | | | | | | | | | | |
Collapse
|
26
|
Nakagawa O, Sasaki Y, Tanaka I, Usui T, Sando T, Muro S, Mori K, Itoh H, Yoshimasa T, Narumiya S. Gene expression of prostacyclin receptor in the hypertrophied heart of spontaneously hypertensive rats. CLINICAL AND EXPERIMENTAL PHARMACOLOGY & PHYSIOLOGY. SUPPLEMENT 1995; 22:S270-2. [PMID: 9072386 DOI: 10.1111/j.1440-1681.1995.tb02912.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
1. Prostacyclin elicits potent vasodilation and inhibition of platelet aggregation through binding to its membrane receptor. The impairment of prostacyclin receptor activity is implicated in various human cardiovascular diseases. We recently succeeded in molecular cloning of cDNA for the mouse, rat, and human prostacyclin receptors. 2. In the present study, we examined the mRNA expression of the prostacyclin receptor in various rat tissues, and further investigated its gene expression in the hypertrophied cardiac ventricles of stroke-prone spontaneously hypertensive rats (SHRSP). 3. In rat tissues, a single RNA band of approximately 3.7 kb was detected by northern blotting analysis using rat prostacyclin receptor cDNA as a probe. In adult Wistar rats, abundant mRNA expression was observed in the aorta, lung and spleen. Substantial amounts of transcript were expressed in the heart, pancreas, thymus and stomach. In contrast, no mRNA expression was detected in the brain. 4. We further examined the mRNA expression of the prostacyclin receptor in the ventricles of 21 week old SHRSP. The ventricles of SHRSP showed remarkable hypertrophy, compared with those of age-matched Wistar-Kyoto (WKY) rats. The expression of prostacyclin receptor mRNA in the hypertrophied ventricles of SHRSP was almost equivalent to that in the ventricles of WKY. 5. The present study revealed the gene expression of the prostacyclin receptor in various rat tissues, and further demonstrated the receptor mRNA expression in hypertensive cardiac hypertrophy. The present study will give a clue to investigate the clinical implication of prostacyclin and its receptor.
Collapse
Affiliation(s)
- O Nakagawa
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Hide EJ, Ney P, Piper J, Thiemermann C, Vane JR. Reduction by prostaglandin E1 or prostaglandin E0 of myocardial infarct size in the rabbit by activation of ATP-sensitive potassium channels. Br J Pharmacol 1995; 116:2435-40. [PMID: 8581281 PMCID: PMC1909044 DOI: 10.1111/j.1476-5381.1995.tb15092.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
1. This study examined whether pretreatment of rabbits with infusions of prostaglandin E1 (PGE1) or prostaglandin E0 (PGE0) (which were terminated prior to the onset of ischaemia) reduce myocardial infarct size arising from coronary artery occlusion (60 min) and reperfusion (120 min). In addition, we investigated whether the observed cardioprotective effects of these two prostaglandins were due to the activation of ATP-sensitive potassium (KATP) channels. 2. In the anaesthetized rabbit, infarct size (expressed as a percentage of the area at risk) after 60 min of coronary artery occlusion followed by 2 h of reperfusion was 59 +/- 4% (n = 10). PGE1 or PGE0 treatment (1.0 micrograms kg-1 min-1), administered as 1 h pretreatments (0.05 ml min-1, i.v.), significantly reduced infarct size to 44 +/- 6% (n = 6) or 42 +/- 1% (n = 6), respectively. PGE1 or PGE0 pretreatment resulted in a significant reduction in mean arterial blood pressure, which returned to baseline within 15 min of discontinuation of the infusion (i.e. prior to LAL ligation). 3. The reduction in infarct size afforded by PGE1 was abolished by pretreatment of rabbits with the KATP channel blockers, glibenclamide (60 +/- 4%; n = 8) or 5-hydroxydecanoate (58 +/- 6%; n = 6). Similarly, glibenclamide also largely attenuated the reduction in infarct size afforded by PGE0 (52 +/- 3%; n = 8). 4. We propose that a 1 h pretreatment of PGE1 or PGE0 reduces infarct size by activating protein kinase C resulting in the opening of KATP channels.
Collapse
Affiliation(s)
- E J Hide
- William Harvey Research Institute, St. Bartholomew's Hospital Medical College, London
| | | | | | | | | |
Collapse
|
28
|
Feld S, Li G, Amirian J, Felli P, Vaughn WK, Accad M, Tolleson TR, Swenson C, Ostro M, Smalling RW. Enhanced thrombolysis, reduced coronary reocclusion and limitation of infarct size with liposomal prostaglandin E1 in a canine thrombolysis model. J Am Coll Cardiol 1994; 24:1382-90. [PMID: 7930264 DOI: 10.1016/0735-1097(94)90124-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVES The purpose of this study was to test the hypothesis that liposomal prostaglandin E1 (TLC C-53) would result in more rapid thrombolysis, less reocclusion and smaller infarct size when administered with heparin and streptokinase in a canine thrombolysis model. BACKGROUND In experimental animals, prostaglandin E1 has been shown to augment thrombolysis, improve coronary flow and reduce infarct size when infused directly into the left atrium. TLC C-53 is a stable preparation of prostaglandin E1 bound by phospholipid microspheres that produces fewer adverse hemodynamic effects during intravenous use. METHODS To investigate the effects of TLC C-53 on coronary patency and infarct salvage, we studied 30 conditioned open chest dogs. After coil-induced left anterior descending coronary artery occlusion and 1 h of clot maturation, the dogs were randomly assigned to receive a 10-min intravenous infusion of either TLC C-53 (2 micrograms/kg body weight) or placebo. Both groups then received intravenous heparin and streptokinase. Hemodynamic variables and Doppler coronary flow were monitored, and myocardial blood flow was determined using radioactive microspheres. Infarct size was assessed with triphenyltetrazolium chloride staining. RESULTS Thrombolysis time was accelerated from 79 +/- 38 to 47 +/- 9 min (mean +/- SD), and coronary patency was greater (100% vs. 50%) with TLC C-53 than with placebo (p < 0.05). Moreover, for arteries that recanalized, coronary Doppler flow and myocardial perfusion were more severely impaired with placebo. Infarct size as a percent of the area at risk was higher (p < 0.05) with placebo (51 +/- 15%) than with TLC C-53 (33 +/- 14%). Neutrophil infiltration into ischemic myocardium determined by myeloperoxidase assay was also significantly greater in the placebo group. CONCLUSIONS TLC C-53 administered intravenously before thrombolytic therapy resulted in a significant acceleration of thrombolysis time, improvement in coronary patency and blood flow during reperfusion and a reduction in infarct size.
Collapse
Affiliation(s)
- S Feld
- Division of Cardiology, University of Texas Health Science Center, Houston
| | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Ueno Y, Miyauchi Y, Nishio S. Beraprost sodium protects occlusion/reperfusion injury in the dog by inhibition of neutrophil migration. GENERAL PHARMACOLOGY 1994; 25:427-32. [PMID: 7926586 DOI: 10.1016/0306-3623(94)90192-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
1. The effects of beraprost sodium (beraprost) on myocardial infarct size in an anesthetized open-chest canine model of regional myocardial ischemia and reperfusion were investigated. 2. Administration of beraprost (300 ng/kg/min, intravenously) to dogs 45 min after left circumflex coronary artery occlusion until 105 min after reperfusion resulted in a significant reduction in infarct size. 3. The values of control and beraprost treated infarct size expressed as a percentage of the total left ventricle were 15 +/- 3% and 4 +/- 2%, respectively. 4. Reperfusion arrhythmia, plasma creatine phosphokinase (CK) and lactate dehydrogenase (LDH) level were significantly suppressed by treatment with beraprost. 5. By histological examination, beraprost proved to reduce neutrophil migration in the ischemic myocardium after 5 h reperfusion. 6. Therefore, it is suggested that the cytoprotective effect of beraprost during myocardial ischemia and reperfusion may be the consequence of the inhibition of neutrophil migration.
Collapse
Affiliation(s)
- Y Ueno
- Toray Industries Inc., Basic Research Laboratories, Kamakura, Japan
| | | | | |
Collapse
|
30
|
Ueno Y, Shigenobu K, Nishio S. Effects of beraprost on the transmembrane potentials of guinea-pig ventricular muscles during normoxia and hypoxia-reoxygenation. Br J Pharmacol 1993; 109:1014-9. [PMID: 8401913 PMCID: PMC2175748 DOI: 10.1111/j.1476-5381.1993.tb13722.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
1. The present study was performed to determine whether beraprost, a new stable analogue of prostacyclin, may exert beneficial effects on the transmembrane action potentials during normoxia and hypoxia-reoxygenation in isolated right ventricular muscles of the guinea-pig. 2. Under normal oxygenation, beraprost (0.01-100 mumol-1) had no effects on the electrophysiological parameters. 3. Hypoxic conditions induced a decrease in action potential duration (APD) without affecting other action potential parameters. Beraprost inhibited this hypoxia-induced decrease in APD. However, beraprost had no effect on the decrease in contractile force induced by hypoxia, whereas it significantly improved the recovery of contractile force after reoxygenation. 4. Pinacidil-induced shortening of APD was not antagonized by beraprost. 5. Hypoxia significantly decreased the myocardial adenosine triphosphate (ATP) level, which was also prevented by beraprost. 6. These results suggested that beraprost may inhibit the hypoxia-induced shortening of APD by some mechanisms which contribute to the maintenance of muscle ATP level.
Collapse
Affiliation(s)
- Y Ueno
- Toray Industries, Inc., Basic Research Laboratories, Kamakura, Japan
| | | | | |
Collapse
|
31
|
Hasegawa J, Komatsu H, Matsumoto S, Enzan K, Mitsuhata H. Prostaglandin E1 increased cardiac contractility in cardiac arrest during open-heart surgery. J Anesth 1993; 7:364-7. [PMID: 15278826 DOI: 10.1007/s0054030070364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/1992] [Accepted: 12/01/1992] [Indexed: 10/26/2022]
Affiliation(s)
- J Hasegawa
- Department of Anesthesiology, Hiraka General Hospital, Yokote, Japan
| | | | | | | | | |
Collapse
|
32
|
Abstract
Although much emphasis has been placed on the role of cholesterol and lipoproteins in atherosclerotic plaque formation, recent studies suggest that lipids have other vascular actions which may contribute to the pathogenesis of myocardial ischemia. These include deleterious effects of lipids on platelet and endothelial cell function, coagulation, fibrinolysis, and prostacyclin metabolism. The purpose of this report is to review recent data regarding the nonatherogenic effects of lipids and provide insight as to how lipid lowering might contribute to clinically important improvements in vascular biology.
Collapse
Affiliation(s)
- F E Kuhn
- Georgetown University Medical Center, Washington, D.C. 20007
| | | | | |
Collapse
|
33
|
|
34
|
Bassenge E, Heusch G. Endothelial and neuro-humoral control of coronary blood flow in health and disease. Rev Physiol Biochem Pharmacol 1990; 116:77-165. [PMID: 2293307 DOI: 10.1007/3540528806_4] [Citation(s) in RCA: 94] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- E Bassenge
- Institut für Angewandte Physiologie, Universität Freiburg, FRG
| | | |
Collapse
|
35
|
Topol EJ, Ellis SG, Califf RM, George BS, Stump DC, Bates ER, Nabel EG, Walton JA, Candela RJ, Lee KL. Combined tissue-type plasminogen activator and prostacyclin therapy for acute myocardial infarction. Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) 4 Study Group. J Am Coll Cardiol 1989; 14:877-84. [PMID: 2477426 DOI: 10.1016/0735-1097(89)90458-0] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Current limitations of recombinant tissue-type plasminogen activator (rt-PA) therapy for acute myocardial infarction include failure to achieve recanalization in 25% of patients, reocclusion and reperfusion injury. Iloprost, a stable analogue of prostacyclin (PGI2), has been demonstrated to facilitate thrombolysis and reduce myocardial stunning in experimental models. To evaluate combined therapy, rt-PA (100 mg 3 h) and Iloprost (2 ng/kg per min for 48 h) were administered to 25 patients and then rt-PA alone (same dose) was given to an additional 25 patients with evolving myocardial infarction. At 90 min after drug administration, infarct-related vessel patency was observed in 11 (44%) of 25 who received rt-PA plus Iloprost compared with 15 (60%) of 25 who received rt-PA alone (p = 0.26). At 1 week, reocclusion had occurred in 3 (14%) of 21 patients who received combined therapy compared with 6 (26%) of 23 patients treated with rt-PA alone (p = 0.46). Ejection fraction increased significantly from baseline to 7 days for rt-PA alone whereas it decreased with combined therapy (rt-PA alone whereas it decreased with combined therapy (rt-PA alone: 47.3 +/- 11.5% at baseline to 50.4 +/- 9.8% at 7 days; rt-PA plus Iloprost: 51.3 +/- 10.1% at baseline to 49.0 +/- 9.4% at 7 days; difference between groups p = 0.05). At 4 h after therapy, fibrinogen decreased 33% for rt-PA plus Iloprost compared with a 52% for rt-PA alone (p = 0.001). Fibrinogen degradation products increased 60% more for rt-PA alone than for rt-PA plus Ilprost. Thus, the combination of rt-PA plus Iloprost at the doses employed did not improve immediate or follow-up coronary artery patency or left ventricular functional recovery compared with that achieved with rt-PA alone.
Collapse
Affiliation(s)
- E J Topol
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Farber NE, Gross GJ. Prostaglandin E1 attenuates postischemic contractile dysfunction after brief coronary occlusion and reperfusion. Am Heart J 1989; 118:17-24. [PMID: 2741783 DOI: 10.1016/0002-8703(89)90066-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We have previously demonstrated that administration of the prostacyclin analogue iloprost improved postischemic functional recovery in reversibly injured ischemic-reperfused myocardium. The present study investigated the effects of administering an endogenous vasodilator prostanoid, prostaglandin E1 (PGE1), in the stunned myocardium (15 minutes of coronary artery occlusion and 3 hours of reperfusion) of anesthetized dogs. The percentage of regional myocardial segment shortening (%SS) after administration of PGE1 by two routes, intravenously (1 microgram/kg/min) or intraatrially (0.1 microgram/kg/min), to avoid pulmonary metabolism, 15 minutes before and throughout the period of occlusion, was compared to %SS in a control group treated with saline solution. Nearly equivalent reductions in mean arterial pressure during occlusion compared to pretreatment control (PTC) values were produced by intravenous (33%) or intraatrial (25%) PGE1. There was no difference in transmural myocardial blood flow (radioactive microsphere technique) in the ischemic region between the PGE1-treated and control groups at any time. Although there were no differences in %SS in the nonischemic region between groups throughout the experiment, postischemic recovery of segment function in the ischemic-reperfused area was significantly improved (p less than 0.05) at all times during reperfusion by intravenous PGE1 (%SS of PTC: 30 minutes = 65 +/- 8; 3 hours = 58 +/- 7) or intraatrial PGE1 (%SS of PTC: 30 minutes = 57 +/- 12; 3 hours = 50 +/- 4) compared to the control group (%SS of PTC: 30 minutes = 25 +/- 13; 3 hours = 10 +/- 13). Thus treatment with PGE1 attenuates postischemic contractile dysfunction in the stunned myocardium.2+ both.
Collapse
Affiliation(s)
- N E Farber
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee 53226
| | | |
Collapse
|
37
|
Auinger C, Virgolini I, Weissel M, Bergmann H, Sinzinger H. Prostacyclin I2 (PGI2) increases left ventricular ejection fraction (LVEF). Prostaglandins Leukot Essent Fatty Acids 1989; 36:149-54. [PMID: 2675122 DOI: 10.1016/0952-3278(89)90054-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In order to evaluate the effect of PGI2 on left ventricular ejection fraction (LVEF) an intravenous infusion in 10 patients (3 males, 7 females; 36 to 63 years) with an impaired LVEF (34.7 +/- 14.8%) was performed. LVEF was determined by means of 99mTc-pertechnetate radionuclide ventriculography. An increase of LVEF to 36.2 +/- 13.5% during administration of PGI2 at a rate of 1 ng/kg/min for 15 min and to 43.8 +/- 15.8% during a rate of 5 ng/kg/min (p less than 0.01) for an additional 15 min was observed. Analyzing the data in more detail in 6 patients, an improvement in LVEF became obvious during the administration of 1 ng/kg/min (108, 109, 116, 118, 121, and 123% of pre-infusion value, respectively). In 5 out of these 6 patients a dose-increment to 5 ng/kg/min further increased LVEF (139, 179, 187, 148, and 128% of pre-infusion value, respectively). In contrast, in the other 4 patients no response of LVEF to PGI2 at a rate of 1 ng/kg/min could be observed. However, in 2 out of these 4 patients LVEF increased during the administration of 5 ng/kg/min (111 and 117% of pre-infusion value). Individual changes in hemodynamic parameters showed no correlation to the improvement seen in LVEF in response to PGI2. It is concluded that PGI2 may exert beneficial effects on LVEF, and might be used in certain clinical conditions, such as before heart transplantation, to achieve a temporary improvement in LVEF.
Collapse
Affiliation(s)
- C Auinger
- Dept. of Nuclear Medicine, University of Vienna, Austria
| | | | | | | | | |
Collapse
|
38
|
Hori S, Nakazawa H, Ohnishi Y, Yoshino H, Murayama A, Nishikawa Y, Nakamura Y, Horikawa M, Hoshino T, Bessho M. A rapid cross-sectioning and freeze-clamping device for the beating canine heart. J Mol Cell Cardiol 1989; 21:203-10. [PMID: 2664189 DOI: 10.1016/0022-2828(89)90862-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A new sampling method of cross-sectioning the canine heart in situ was developed. A mechanical device, driven by spring power, enabled cross-sectioning of a short-axis plane of the beating canine heart (4 mm thick) with high speed rotating blades, at a pre-determined phase of the cardiac cycle, and instantaneous freeze-clamping (2.4 mm thick) with pre-cooled aluminum blocks, all within 120 ms. By this method, the anatomical structures of the sample were well preserved. Transmural metabolism and flow distribution were instantaneously fixed and high resolution of the two-dimensional redox state was obtained by application of NADH fluorescence photography. Micro-samplings from the desired portion of the cross-sectional slice were possible at -190 degrees C. NADH fluorescence of the samples did not increase from the surface to 1.2 mm in depth, confirming that there was no ischemic artifact. With the present technique, a heart sample in which transmural metabolism, and the redox state, are fixed and visualized is attainable, thus providing a new tool for the study of myocardial ischemia.
Collapse
Affiliation(s)
- S Hori
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Feldman RL, Rose B, Verbust KM. Hemodynamic and angiographic effects of prostaglandin E1 in coronary artery disease. Am J Cardiol 1988; 62:698-702. [PMID: 3421167 DOI: 10.1016/0002-9149(88)91205-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effects of prostaglandin E1 (PGE1) were assessed in 24 patients with coronary artery disease. Quantitative coronary angiography was performed in 15 patients. PGE1 was found to produce dilation of coronary stenoses (6 +/- 12% to intravenous PGE1, difference not significant, 19 +/- 22% to intracoronary PGE1, p less than 0.05), but usually no change in the diameter of angiographically normal segments. In these patients intracoronary nitroglycerin consistently dilated the normal segments not altered with PGE1 and often led to further dilation of the stenoses. In 9 other patients who were undergoing coronary angioplasty, hemodynamics and the time to ischemia induced by coronary occlusion were measured. In both patient groups PGE1 led to decreases in aortic, pulmonary artery and pulmonary arterial wedge pressures and an increase in heart rate (all p less than 0.05). Before coronary occlusion PGE1 produced coronary vasodilation manifested by preservation in coronary sinus flow (130 +/- 41 to 126 +/- 42 ml/min, difference not significant); as aortic pressure declined coronary resistance decreased (0.9 +/- 0.3 to 0.8 +/- 0.3 mm Hg/ml/min, p less than 0.05). During coronary occlusion residual flow to the affected region was usually similar to control occlusions (37 +/- 20 to 36 +/- 25 ml/min, difference not significant) and collateral resistance was decreased (3.2 +/- 2.9 to 2.9 +/- 2.6 mm Hg/ml/min, p less than 0.05). However, time to ischemia usually remained unchanged. PGE1 shows an interesting angiographic and hemodynamic profile in patients with coronary artery disease. Although no obvious clinical benefit was seen, PGE1 was safely administered both intravenously and directly into narrowed coronary arteries.
Collapse
Affiliation(s)
- R L Feldman
- Department of Medicine, University of Florida
| | | | | |
Collapse
|
40
|
Herbaczynska-Cedro K, Karwatowska-Prokopczuk E, Michalowski J, Wennmalm A. Prostacyclin and regional coronary blood flow in experimental myocardial infarction. CLINICAL PHYSIOLOGY (OXFORD, ENGLAND) 1988; 8:255-66. [PMID: 3042272 DOI: 10.1111/j.1475-097x.1988.tb00269.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Infusion of prostacyclin (PGI2) has been reported to affect infarct size and myocardial blood flow favourably in various animal models of myocardial ischaemia. Recent data suggest that a similar effect of PGI2 may occur also in humans with acute myocardial infarction. We addressed the hypothesis that PGI2 redistributes myocardial blood flow following coronary ligation, and that this effect favours perfusion of myocardium at risk and thereby limits infarct size. Following ligation of a distal branch of the left coronary artery in anaesthetized dogs, PGI2 (2-4 ng/kg/min) was infused for 72 h. Regional myocardial blood flow was assessed immediately after the coronary ligation and at the end of the drug infusion, by injection of 57Co- and 113Sn-labelled microspheres, respectively. Coronary ligation reduced regional coronary blood flow by 40-70%. During the subsequent 72 h the blood flow increased, being at the end of the period 50-70% of the flow in the non-ischaemic myocardium. PGI2 did not affect the spontaneous improvement of regional myocardial blood flow, as assessed at the end of the infusion. PGI2 also failed to affect infarct size, either when expressed in relation to total left ventricular mass, or in relation to area at risk. We conclude that PGI2, when infused immediately after coronary ligation in dogs in a clinically relevant dose, neither affects regional myocardial blood flow in the ischaemic regions, nor the size of the myocardial infarction.
Collapse
Affiliation(s)
- K Herbaczynska-Cedro
- Medical Research Centre, Polish Academy of Sciences, Department of Clinical Physiology, Warsaw
| | | | | | | |
Collapse
|
41
|
Chiariello M, Golino P, Cappelli-Bigazzi M, Ambrosio G, Tritto I, Salvatore M. Reduction in infarct size by the prostacyclin analogue iloprost (ZK 36374) after experimental coronary artery occlusion-reperfusion. Am Heart J 1988; 115:499-504. [PMID: 2449815 DOI: 10.1016/0002-8703(88)90796-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In this study we attempted to determine whether administration of iloprost (ZK 36374), a chemically stable prostacyclin analogue, would reduce infarct size after experimental coronary artery occlusion and reperfusion. One hour of coronary artery occlusion was performed in 28 open-chest, anesthetized rabbits++, followed by 5 hours of reperfusion. Two minutes after occlusion, 99mTc-labeled albumin microspheres were injected into the left atrium for later assessment of the area at risk of infarction. Fifteen minutes after occlusion animals were randomly assigned to either the treatment group (iloprost, 1.2 micrograms/kg/min intravenously for 6 hours; n = 14) or the control group (n = 14). In vitro platelet aggregation was inhibited in rabbits receiving iloprost. In 10 rabbits (five treated and five control) regional myocardial blood flow was also measured by means of differentially labeled radioactive microspheres. Infarct size was significantly smaller in treated rabbits (53.6 +/- 4.1% of the risk zone vs 89.4 +/- 3.8% in control rabbits; p less than 0.001). Flow to the nonischemic myocardium was higher in treated animals, that is, 1.87 +/- 0.20 ml/min/gm of tissue 50 minutes after occlusion and 1.90 +/- 0.20 ml/min/gm of tissue 4 hours after reperfusion, compared with 1.54 +/- 0.20 and 1.64 +/- 0.30 ml/min/gm of tissue, respectively, in control rabbits (p less than 0.01). Collateral flow to the ischemic region was not affected by the drug. Mean arterial blood pressure, heart rate, and pressure-rate product in treated rabbits were not significantly different from values in control rabbits. In conclusion, administration of iloprost reduced myocardial infarct size in this model of myocardial ischemia and reperfusion in absence of major hemodynamic effects.
Collapse
Affiliation(s)
- M Chiariello
- Department of Medicine, Second School of Medicine, University of Naples, Italy
| | | | | | | | | | | |
Collapse
|
42
|
Affiliation(s)
- P W Armstrong
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | | | | |
Collapse
|
43
|
Abstract
Ischemic myocardium generates stimuli for neutrophil chemotaxis before the final extent of irreversible ischemic injury is attained. Reperfusion accelerates the infiltration of ischemic myocardium by neutrophils. Oxygen radicals released by the activated neutrophils may exacerbate the tissue damage caused by ischemia. Neutrophil depletion by antiserum was shown to limit infarct size in dogs undergoing coronary occlusion for 90 minutes followed by reperfusion for 6 or 72 hours, but not in dogs undergoing occlusion for 4 hours. Prostacyclin, which inhibits the generation of superoxide anions by neutrophils, also limited canine myocardial injury despite no effect on collateral blood flow. Iloprost, an analogue of prostacyclin that inhibits neutrophils also reduced infarct size, while SC39902, an analogue that does not inhibit neutrophils, did not alter infarct size. The results suggest that oxygen radicals released by activated neutrophils play a role in the pathophysiology of myocardial injury due to ischemia followed by reperfusion.
Collapse
Affiliation(s)
- S W Werns
- Department of Internal Medicine (Division of Cardiology), University of Michigan Medical School, Ann Arbor 48109
| | | |
Collapse
|
44
|
Miura T, Yellon DM, Kingma J, Downey JM. Protection afforded by allopurinol in the first 24 hours of coronary occlusion is diminished after 48 hours. Free Radic Biol Med 1988; 4:25-30. [PMID: 3342999 DOI: 10.1016/0891-5849(88)90007-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Experiments were performed to test whether the reduction in infarct size afforded by allopurinol following 24 h of permanent coronary artery occlusion is sustained over the subsequent 24 h. A dog's coronary artery was occluded with an embolus followed by injection of radiomicrospheres into the left ventricle to mark the ischemic region and to measure regional blood flow. Dogs were sacrificed either 24 h or 48 hours after embolization. The infarcts were delineated by failure to stain with triphenyl tetrazolium chloride and the ischemic zones were visualized by autoradiography of the heart slices. Dogs in the treatment groups received 600 mg of allopurinol PO 18 h before surgery, and a 10 mg/kg IV bolus 15 minutes before embolization followed by constant IV infusion of 55 mg/kg/24 h until sacrifice. A close correlation in the control animals between the percent of the ischemic zone which infarcted and collateral blood flow was used to predict a nonintervention infarct size in each treatment animal. Allopurinol treatment caused 17.9 +/- 3.3% less of the risk zone to be tetrazolium negative after 24 hours of ischemia than that seen in untreated animals. Less allopurinol induced salvage was observed in the 48 hour drug group with only a 11.1 +/- 3.3% limitation in infarct size. Furthermore, the effect was inconsistent at 48 h with only 2 dogs showing salvage. We conclude that allopurinol delays but does not prevent infarction in the permanent occlusion model.
Collapse
Affiliation(s)
- T Miura
- Department of Physiology, College of Medicine, University of South Alabama, Mobile 36688
| | | | | | | |
Collapse
|
45
|
|
46
|
Sharma B, Wyeth RP, Gimenez HJ. Reply. Am J Cardiol 1987. [DOI: 10.1016/0002-9149(87)90439-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
47
|
Feiring AJ, Johnson MR, Kioschos JM, Kirchner PT, Marcus ML, White CW. The importance of the determination of the myocardial area at risk in the evaluation of the outcome of acute myocardial infarction in patients. Circulation 1987; 75:980-7. [PMID: 3568313 DOI: 10.1161/01.cir.75.5.980] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
On the basis of animal studies, we postulated that the size of the perfusion field (risk area) of an occluded coronary artery would be an important determinant of outcome in patients with acute myocardial infarction. To test this hypothesis, we measured size of the risk area in 27 patients with acute myocardial infarction by the intracoronary injection of 99mTc-macroaggregated albumin and gated nuclear imaging. After injection of the albumin spheres (5.3 +/- 1.4 hr after the onset of chest pain) streptokinase was administered and in 16 of 27 patients (59%) effective thrombolysis was achieved. Since none of the patients had evidence of a prior acute myocardial infarction, the 3 day nuclear left ventricular ejection fraction (LVEF) was considered an index of infarct size. Response to thrombolysis was analyzed according to success or failure of reperfusion and the size of the risk area (small risk area less than 25%, large risk area greater than 25% of left ventricular surface area). Standard clinical indexes correlated poorly with size of the risk area: electrocardiographic variables (r = .37), left ventricular end-diastolic pressure (r = .23), cardiac index (r = .55), and the LVEF obtained from a right anterior oblique contrast ventriculogram (r = .31). The coronary vessel responsible for the acute myocardial infarction significantly influenced size of the risk area (left anterior descending, 38 +/- 5% [mean +/- SD] vs circumflex or right coronary artery, 17 +/- 4%). However, knowledge of the site of coronary occlusion within a vessel was not helpful in predicting the size of the area at risk.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
48
|
Körmöczy PS, Vértesi C, Mikus E, Tardos L, Kovács G. Cardioprotective effect of prostacyclin and 7-oxo-PGI2 in rats against chronic isoproterenol damage. PROSTAGLANDINS 1987; 33:505-16. [PMID: 3299498 DOI: 10.1016/0090-6980(87)90274-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Isoproterenol (ISO) was injected in 5 mg/kg i.p. doses to rats, daily for two weeks. We evaluated the developed myocardial hypoxia and necrosis quantitatively by histological methods. To follow the time course of cardioprotection prostacyclin or 7-oxo-PGI2 were injected daily, i.p. 5, 30 min and 1, 2, 3, 4 hours before or after the ISO to groups of ten rats, respectively. Cardioprotection was defined as the reduction of necrotized areas and was expressed as percentage change compared to the control (saline treated) group. 1 microgram/kg PGI2 and 50 micrograms/kg 7-oxo-PGI2+ showed nearly equipotent cardioprotection (37.3-7.9% and 38.3-6.8%, respectively). The peak effect of both compounds appeared when injected prior to ISO in the 120. min but the action of 7-oxo-PGI2 was more prolonged. The different doses of prostacyclin analogs given after the ISO injection were ineffective with the exception of 50 micrograms/kg 7-oxo-PGI2 (29.75 +/- 5.2%).
Collapse
|
49
|
Abstract
The available data clearly suggest large alterations in myocardial eicosanoid generation during myocardial ischaemia and demonstrate important actions of eicosanoids on myocardial function during ischaemic conditions. These actions include direct effects on the injured myocardium as well as influences on other target cells, such as platelets and leukocytes. Selective modifications of eicosanoid generation, for example by providing exogenous PGI2 or by inhibiting oxygen toxicity are most challenging approaches for the design of new and potentially valuable cardioprotective agents. Antagonism of thromboxane formation and/or action might be of some value in ischaemia but appears to be less important for reperfusion injury. Leukotrienes and other noncyclic fatty acid peroxidation products are another group of potentially deleterious agents and there is a definite need for more selective inhibitors of leukotriene formation and/or action to establish their role in ischaemia.
Collapse
Affiliation(s)
- K Schrör
- Institut für Pharmakologie, Universität Düsseldorf, F. R. G
| |
Collapse
|
50
|
Simpson PJ, Mitsos SE, Ventura A, Gallagher KP, Fantone JC, Abrams GD, Schork MA, Lucchesi BR. Prostacyclin protects ischemic reperfused myocardium in the dog by inhibition of neutrophil activation. Am Heart J 1987; 113:129-37. [PMID: 3541554 DOI: 10.1016/0002-8703(87)90020-2] [Citation(s) in RCA: 133] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Prostacyclin (PGI2) and the stable PGI2 analogue SC39902 (6,9 alpha-epoxy,5S-fluoro-11 alpha, 15S-dehydroxyprosta-6,13E-dien-1-oic acid, sodium salt) were studied in anesthetized open-chest dogs subjected to 90 minutes of left circumflex coronary artery (LCCA) occlusion and 6 hours of reperfusion. PGI2 (50 ng/kg/min, infused into the left atrium) reduced infarct mass by 59% compared to control, but SC39902 (1.5 micrograms/kg/min) failed to produce a significant reduction in infarct size. Both PGI2 and SC39902 reduced mean arterial blood pressure, heart rate, and rate-pressure product to the same extent. Regional myocardial blood flow measured with radiolabelled tracer microspheres did not demonstrate an increase in regional blood flow to the ischemic myocardium during the 90 minutes of LCCA occlusion in the PGI2 and control treatment groups. Canine neutrophils were isolated from whole blood and activated with opsonized zymosan. PGI2 produced a concentration-dependent inhibition of neutrophil activation as measured by superoxide production in vitro, whereas SC39902 failed to effectively inhibit neutrophil activation. Neutrophil migration into inflammatory skin lesions was effectively attenuated when dogs were pretreated with PGI2 (50 ng/kg/min, intravenously). Therefore, it is suggested that the cytoprotective effect of PGI2 during myocardial ischemia and reperfusion is related to an inhibition of neutrophil migration and the production of cytotoxic activated oxygen species.
Collapse
|