Inhaled nitric oxide decreases infarction size and improves left ventricular function in a murine model of myocardial ischemia-reperfusion injury

2006 ◽  
Vol 291 (1) ◽  
pp. H379-H384 ◽  
Author(s):  
Ryuji Hataishi ◽  
Ana Clara Rodrigues ◽  
Tomas G. Neilan ◽  
John G. Morgan ◽  
Emmanuel Buys ◽  
...  

To learn whether nitric oxide (NO) inhalation can decrease myocardial ischemia-reperfusion (I/R) injury, we studied a murine model of myocardial infarction (MI). Anesthetized mice underwent left anterior descending coronary artery ligation for 30, 60, or 120 min followed by reperfusion. Mice breathed NO beginning 20 min before reperfusion and continuing thereafter for 24 h. MI size and area at risk were measured, and left ventricular (LV) function was evaluated using echocardiography and invasive hemodynamic measurements. Inhalation of 40 or 80 ppm, but not 20 ppm, NO decreased the ratio of MI size to area at risk. NO inhalation improved LV systolic function, as assessed by echocardiography 24 h after reperfusion, and systolic and diastolic function, as evaluated by hemodynamic measurements 72 h after reperfusion. Myocardial neutrophil infiltration was reduced in mice breathing NO, and neutrophil depletion prevented inhaled NO from reducing myocardial I/R injury. NO inhalation increased arterial nitrite levels but did not change myocardial cGMP levels. Breathing 40 or 80 ppm NO markedly and significantly decreased MI size and improved LV function after ischemia and reperfusion in mice. NO inhalation may represent a novel method to salvage myocardium at risk of I/R injury.

1992 ◽  
Vol 263 (3) ◽  
pp. H771-H777 ◽  
Author(s):  
M. R. Siegfried ◽  
C. Carey ◽  
X. L. Ma ◽  
A. M. Lefer

Intravenous administration of SPM-5185 [N-nitratopivaloyl-S-(N–-acetylalanyl)-cysteine ethyl ester], a cysteine-containing nitric oxide (NO) donor, or SPM-5267 [pivaloyl-S-(N–-acetylalanyl)-cysteine ethyl ester], an analogue of SPM-5185 that lacks the NO moiety, was studied in a feline myocardial ischemia-reperfusion model. Administration of SPM-5185 (1 mg/kg), followed by a 2-mg.kg-1.h-1 infusion starting 10 min before reperfusion, resulted in significant protection 4.5 h postreperfusion. In the myocardial ischemia (MI)+SPM-5267 group, 38 +/- 4% of the area at risk was necrotic, whereas the necrotic area/area at risk was only 7 +/- 2% in the MI+SPM-5185 group (P less than 0.01). Moreover, SPM-5185 treatment markedly attenuated the endothelial dysfunction observed in the left anterior descending coronary artery after reperfusion by 50%. These beneficial effects occurred despite the absence of a significant change in myocardial oxygen demand, as measured by the pressure-rate index. In vitro experiments demonstrated that SMP-5185, but not SPM-5267, decreased adherence of neutrophils to the coronary vascular endothelium and decreased production of superoxide radicals. Therefore, a likely mechanism of the observed cardioprotection by SPM-5185 involves attenuation of polymorphonuclear leukocyte-induced endothelial dysfunction.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Stefan Frantz ◽  
Johann Bauersachs ◽  
Anna Adamek ◽  
Nadja Blomer ◽  
Georg Ertl ◽  
...  

Formation of fibrin is critical for limiting blood loss at a site of blood vessel injury (hemostasis), but may also contribute to vascular thrombosis and thus exaggerate myocardial ischemia/reperfusion injury. Hereditary deficiency of factor XII (FXII), the protease that triggers the intrinsic pathway of coagulation in vitro, is not associated with spontaneous or excessive injury-related bleeding, but can reduce thrombus formation. Therefore, we studied the contribution of FXII for myocardial ischemia reperfusion injury. Following 30 minutes of ischemia and 24 hours of reperfusion infarct size in FXII deficient mice was significantly reduced as compared to wild type controls (infarct/area at risk, WT vs. FXII−/−, 73.5%±4.4% vs. 42.3±1.6%, p<0.001) despite similar area at risk (WT vs. FXII−/−, 28.3%±1.7% vs. 29.9±1.0%, p=n.s.). There was no difference in bleeding complications and bleeding time. Mice deficient in the FXII substrate factor XI were similarly protected from ischemia reperfusion injury (infarct/area at risk, FXI−/−, 16.9%±4.1%, vs. WT p<0.001). The phenotype of FXII−/−mice could be rescued by intravenous application of human FXII (infarct/area at risk, FXII−/−+FXII, 77.3%±8.4%, p<0.001 vs. FXIIKO). WT mice treated with the FXII inhibitor PCK (Pro-Phe-Arg-chloromethylketone) were similarly protected from myocardial ischemia/reperfusion injury (infarct/area at risk, 46.5% ±3.7%, vs. WT p<0.001). The data suggest that the intrinsic pathway is crucial for pathological clotting in myocardial ischemia reperfusion injury. FXII inhibition may offer a selective and safe strategy to reduce ischemic injury.


2014 ◽  
Vol 307 (4) ◽  
pp. H598-H608 ◽  
Author(s):  
Jian Liu ◽  
Peipei Wang ◽  
Luyun Zou ◽  
Jing Qu ◽  
Silvio Litovsky ◽  
...  

High-fat, low-carbohydrate diets (HFLCD) are often eaten by humans for a variety of reasons, but the effects of such diets on the heart are incompletely understood. We evaluated the impact of HFLCD on myocardial ischemia/reperfusion (I/R) using an in vivo model of left anterior descending coronary artery ligation. Sprague-Dawley rats (300 g) were fed HFLCD (60% calories fat, 30% protein, 10% carbohydrate) or control (CONT; 16% fat, 19% protein, 65% carbohydrate) diet for 2 wk and then underwent open chest I/R. At baseline (preischemia), diet did not affect left ventricular (LV) systolic and diastolic function. Oil red O staining revealed presence of lipid in the heart with HFLCD but not in CONT. Following I/R, recovery of LV function was decreased in HFLCD. HFLCD hearts exhibited decreased ATP synthase and increased uncoupling protein-3 gene and protein expression. HFLCD downregulated mitochondrial fusion proteins and upregulated fission proteins and store-operated Ca2+ channel proteins. HFLCD led to increased death during I/R; 6 of 22 CONT rats and 16 of 26 HFLCD rats died due to ventricular arrhythmias and hemodynamic shock. In surviving rats, HFLCD led to larger infarct size. We concluded that in vivo HFLCD does not affect nonischemic LV function but leads to greater myocardial injury during I/R, with increased risk of death by pump failure and ventricular arrhythmias, which might be associated with altered cardiac energetics, mitochondrial fission/fusion dynamics, and store-operated Ca2+ channel expression.


1997 ◽  
Vol 272 (5) ◽  
pp. H2327-H2336 ◽  
Author(s):  
P. Liu ◽  
C. E. Hock ◽  
R. Nagele ◽  
P. Y. Wong

In the present study, the contribution of nitric oxide (NO), superoxide, and peroxynitrite to the inflammatory response induced by myocardial ischemia-reperfusion (MI/R) was investigated. Male Sprague-Dawley rats were anesthetized, and the left main coronary artery was ligated for 20 min and reperfused for 5 h. MI/R induced severe arrhythmias, indicated by a significantly elevated arrhythmia score in the MI/R group compared with that in the sham control group. Creatine kinase activity in the left ventricular free wall of the MI/R group was significantly reduced by 38%. In contrast, myeloperoxidase activity in the left ventricular free wall of the MI/R group was increased by 140%. Similarly, superoxide and tissue NO levels in the ischemic region of the heurt were increased by 140 and 90%, respectively. Superoxide and NO values in the nonischemic regions were similar to the sham control group. Total NO synthase (NOS) activity was elevated by 212%; moreover, inducible NOS (iNOS) activity increased 6.7-fold in the ischemic vs. nonischemic regions. MI/R also induced both systemic and remote organ (lung) inflammatory responses. Circulating neutrophils and plasma NO levels were increased by 163 and 138%, respectively, in MI/R rats compared with sham control animals. NO levels and superoxide generation were increased by 90 and 176%, respectively, in the lung tissues. The expression of iNOS and peroxynitrite generation were demonstrated by immunohistochemical staining with polyclonal anti-iNOS and monoclonal anti-nitrotyrosine antibodies, respectively. Sections of both the ischemic area of the ventricular wall and the lung tissue of MI/R animals exhibited a marked immunoreactivity with anti-iNOS and anti-nitrotyrosine antibodies, indicating the presence of iNOS and nitrotyrosine. Our data indicate that NO, superoxide, and peroxynitrite formation are elevated after reperfusion of the ischemic heart, suggesting that these inflammatory mediators may be involved in MI/R injury.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Fatih Arslan ◽  
Gerard Pasterkamp ◽  
Leo Timmers ◽  
Ben van Middelaar ◽  
Pieter A Doevendans ◽  
...  

OBJECTIVES. Myocardial ischemia/reperfusion (MI/R) injury is characterized by an inflammatory response through NF-κB, increase of infarct size and worsening of cardiac function. Toll-like receptors (TLRs) are part of innate immunity and initiate the same inflammatory reaction. Here we studied in vivo to what extent TLR2 is involved in myocardial damage and what the relative contribution is of TLR2 expression in parenchymal cells and leukocytes to myocardial damage during MI/R in mice. METHODS. C57Bl6J mice underwent 30 minutes ischemia - 24 hours of reperfusion. Four experimental groups were studied: TLR2 knock-out (TLR2 KO) mice (n=10), saline treated wild-type (WT) mice (n=10), generated chimeric WT mice with TLR2 KO bone marrow (BLOOD KO; n=7) and chimeric TLR2 KO mice with WT hematopoietic cells (ORGAN KO; n=7). Saline was administered via the tail vein 5 minutes prior to reperfusion. After 24 hours, the LCA was ligated again at the level marked by the suture left in place. Mice were terminated and infarct size (IS) was measured as a percentage of the area at risk (AAR) using 4% Evans’ blue dye injection in the aortic root and triphenyltetrazolium chloride (TTC) staining (fig. 1). Data are presented as Mean±SEM. RESULTS. The AAR as percentage of the left ventricle was similar between groups: TLR2 KO 41%, saline 41%, Blood KO 41%, Organ KO 42%. Saline treatment resulted in 34.5%±3.3 of infarction, whereas in TLR2 KO mice infarct size decreased to 23.0%±2.9 (p=0.029 vs. saline). Infarct size in BLOOD KO mice was 22.9%±2.7 (p=0.024 vs. saline), while ORGAN KO mice had 33.9%±3.2 (p=0.998 vs. saline) of infarction within the area at risk (fig. 2). CONCLUSION. TLR2 deficiency significantly reduces infarct size with ~33% compared to saline treatment in mice after 30 minutes of ischemia and 24 hours of reperfusion. We show for the first time that TLR2 expression in circulating leukocytes plays an important role in infarction after MI/R injury. Systemic inhibition of TLR2 may be a potential therapeutic target in the treatment of patients with acute myocardial infarction.


2005 ◽  
Vol 289 (5) ◽  
pp. H2265-H2271 ◽  
Author(s):  
Jiangning Tan ◽  
Zhizhong Ma ◽  
Ling Han ◽  
Ruyu Du ◽  
Liming Zhao ◽  
...  

Although great achievements have been made in elucidating the molecular mechanisms contributing to acute myocardial ischemia/reperfusion (I/R) injury, an effective pharmacological therapy to protect cardiac tissues from serious damage associated with acute myocardial infarction, coronary arterial bypass grafting surgery, or acute coronary syndromes has not been developed. We examined the in vivo cardioprotective effects of caffeic acid phenethyl ester (CAPE), a natural product with potent anti-inflammatory, antitumor, and antioxidant activities. CAPE was systemically delivered to rabbits either 60 min before or 30 min after surgically inducing I/R injury. Infarct dimensions in the area at risk were reduced by >2-fold ( P < 0.01) with CAPE treatment at either period. Accordingly, serum levels of normally cytosolic enzymes lactate dehydrogenase, creatine kinase (CK), MB isoenzyme of CK, and cardiac-specific troponin I were markedly reduced in both CAPE treatment groups ( P < 0.05) compared with the vehicle-treated control group. CAPE-treated tissues displayed significantly less cell death ( P < 0.05), which was in part due to inhibition of p38 mitogen-activated protein kinase activation and reduced DNA fragmentation often associated with caspase 3 activation ( P < 0.05). In addition, CAPE directly blocked calcium-induced cytochrome c release from mitochondria. Finally, the levels of inflammatory proteins IL-1β and TNF-α expressed in the area at risk were significantly reduced with CAPE treatment ( P < 0.05). These data demonstrate that CAPE has potent cardioprotective effects against I/R injury, which are mediated, at least in part, by the inhibition of inflammatory and cell death responses. Importantly, protection is conferred when CAPE is systemically administered after the onset of ischemia, thus demonstrating potential efficacy in the clinical scenario.


2012 ◽  
Vol 302 (9) ◽  
pp. H1818-H1825 ◽  
Author(s):  
Wei Zhou ◽  
Yoshihiro Ko ◽  
Peyman Benharash ◽  
Kentaro Yamakawa ◽  
Sunny Patel ◽  
...  

Augmentation of cardiac sympathetic tone during myocardial ischemia has been shown to increase myocardial O2 demand and infarct size as well as induce arrhythmias. We have previously demonstrated that electroacupuncture (EA) inhibits the visceral sympathoexcitatory cardiovascular reflex. The purpose of this study was to determine the effects of EA on left ventricular (LV) function, O2 demand, infarct size, arrhythmogenesis, and in vivo cardiac norepinephrine (NE) release in a myocardial ischemia-reperfusion model. Anesthetized rabbits ( n = 36) underwent 30 min of left anterior descending coronary artery occlusion followed by 90 min of reperfusion. We evaluated myocardial O2 demand, infarct size, ventricular arrhythmias, and myocardial NE release using microdialysis under the following experimental conditions: 1) untreated, 2) EA at P5–6 acupoints, 3) sham acupuncture, 4) EA with pretreatment with naloxone (a nonselective opioid receptor antagonist), 5) EA with pretreatment with chelerythrine (a nonselective PKC inhibitor), and 6) EA with pretreatment with both naloxone and chelerythrine. Compared with the untreated and sham acupuncture groups, EA resulted in decreased O2 demand, myocardial NE concentration, and infarct size. Furthermore, the degree of ST segment elevation and severity of LV dysfunction and ventricular arrhythmias were all significantly decreased ( P < 0.05). The cardioprotective effects of EA were partially blocked by pretreatment with naloxone or chelerythrine alone and completely blocked by pretreatment with both naloxone and chelerythrine. These results suggest that the cardioprotective effects of EA against myocardial ischemia-reperfusion are mediated through inhibition of the cardiac sympathetic nervous system as well as opioid and PKC-dependent pathways.


2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Ana Carolina M Omoto ◽  
Jussara Do Carmo ◽  
Xuan Li ◽  
Zhen Wang ◽  
Alan J Mouton ◽  
...  

Mitochondrial (MT) dysfunction plays an important role in the pathophysiology of myocardial ischemia/reperfusion injury (I/R). We recently showed that leptin, via its actions in the central nervous system (CNS), improves left ventricular (LV) function in a model of heart failure induced by permanent ligation of the left anterior descending coronary artery (LAD). In the present study, we examined if the CNS effects of leptin protect against myocardial ischemia/reperfusion (I/R) injury, and whether chronic intracerebroventricular (ICV) leptin infusion increases MT function and biogenesis in the non-infarcted area of the LV that is at risk but still viable. Male Wistar rats were instrumented with an ICV cannula in the brain lateral ventricle. After recovery and baseline assessment of cardiac function by echocardiography (ECHO), myocardial I/R was induced by temporary (60 min) ligation of the LAD. Vehicle (saline, 0.5 μL/hr) or leptin (0.62 μg/day) was infused chronically for 28 days starting 20 min after reperfusion using osmotic minipumps connected to the ICV cannula. ECHO assessment of cardiac function was performed every week. At the end of week 4, +dP/dt max and Tau were accessed by LV catheterization. Hearts were then collected for evaluation of MT function in isolated cardiac fibers using Oroboros oxygraphy-2k respirometer. ICV leptin treatment improved systolic and diastolic function as evidenced by increased ejection fraction 4 weeks after I/R (46±3 vs. 26±3 %), stroke volume (353±19 vs. 193±27 μL), +dP/dt max (10387±1686 vs. 5022±442 mmHg/s) and reduced Tau (6.5±0.3 vs. 8±0.3 ms) when compared with vehicle-treated rats. In addition, ICV leptin infusion significantly increased ATP-linked respiration (55±3 vs. 39±1 %), reduced proton leak (45±3 vs. 61±1 %), and improved MT reserve capacity (42±5 vs. 27±2 %). Improved MT function was associated with increased MT Complex I- mediated respiration (47±6 vs. 26±1 pmolO 2 /s - mg). ICV leptin treatment also increased PGC1 α protein expression and COX3 gene expression, indicating enhanced MT biogenesis. These results demonstrate that chronic ICV leptin infusion improves cardiac function following I/R injury and suggests that leptin’s CNS-mediated cardioprotective effects may involve improved myocardial MT function and biogenesis.


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