Abstract 162: Influence of Age and Ischemia on Cardiac Subsarcolemmal and Interfibrillar Mitochondria in a Novel Model of Estrogen Deficiency

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Alexandra M Garvin ◽  
Nicole C Aurigemma ◽  
Donna H Korzick
Keyword(s):  
Mitochondrial Permeability Transition ◽  
Protective Efficacy ◽  
Ischemia Reperfusion ◽  
Female Rats ◽  
Coronary Artery Ligation ◽  
Cyclophilin D ◽  
Artery Ligation ◽  
Retention Capacity ◽  
Novel Model

Altered mitochondrial respiration (MR) and calcium retention capacity (CRC) are proposed cardiac cell death mechanisms exacerbated by aging in males. The present study aimed, for the first time, to determine changes in mitochondrial subpopulation function with age and ischemia/reperfusion (I/R) injury in the female heart. A novel model to recapitulate human menopause/age interactions was used in F344 female rats ovariectomized (OVX) at 15mo and studied at 24mo (MO OVX; n=15), vs adult (6mo; n=18). MR and CRC were assessed in isolated subsarcolemmal (SSM) and interfibrillar (IFM) mitochondria following in vivo coronary artery ligation (CAL; 31 min I and 10 min R) or sham. State 3 MR energized by either complex I (CI) or complex II (CII) substrates was selectively reduced by age in SSM (p<.02), and by I/R in IFM (p<.05). The I/R-dependent decrease in CRC was 64% (18 vs 29.5) greater in MO OVX vs. adult IFM, suggesting earlier mitochondrial permeability transition pore (MPTP) opening. At CI, but not CII, cyclosporine A (CsA) enhanced CRC 20% (103 vs 86) more in SSM and 75% (98 vs 56) more in IFM from adult compared to MO OVX, suggesting reduced protective efficacy with age and MPTP involvement. Additionally, mitochondrial cyclophilin D increases with age, while cytoplasmic RIP1 is increased with age and I/R further implicating the MPTP mechanism and link with programmed necrosis in the aged female heart. In contrast to males, our data suggest a sex-specific phenotype whereby reductions in both SSM and IFM dynamics may play an additive role in the enhanced susceptibility to I/R injury and myocardial infarction in the aged female heart, which remains the leading cause of death in older women.

Abstract 411: Endogenous miRNA Induced By Ischemic Preconditioning Reduces Myocardial Infarct Size following Ischemia/Reperfusion In Mice

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Chang Yin ◽  
Fadi N Salloum ◽  
Rakesh C Kukreja
Keyword(s):  
Infarct Size ◽  
Ischemic Preconditioning ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Protective Role ◽  
Coronary Artery Ligation ◽  
Myocardial Infarct Size ◽  
Artery Ligation ◽  
Buffer Control

BACKGROUND: Due to its short length (~24 nt) and non-coding nature, microRNA (miRNA) used to be regarded as “evolutionary transcriptional debris”. Recent evidence suggests that miRNA is a novel regulator for transcription and translation. It is known that brief episodes of ischemia during ischemic preconditioning (IPC) trigger complex genetic pro-survival program that results in modulation of several key proteins involved in protection against I/R injury. We hypothesized that miRNA synthesized during IPC is the potential mediator of such protection. METHODS / RESULTS : Hearts were isolated from 3 groups (n = 6/group) of adult ICR mice and subjected to the following treatments in Langendorff mode: 120 min of perfusion with Krebs-Henseleit buffer (control); 30 min global ischemia followed by 1 hr reperfusion (I/R); 2 cycles of 30 sec ischemia and 90 sec reperfusion followed by 30 min ischemia and 1 hr reperfusion (IPC). Infarct size (IS) was measured by triphenyl tetrazolium staining. IPC in the Langendorff model reduced IS from 29.7 ± 2.1% in the I/R hearts to 9.1 ± 1.8 % in the IPC group. This protection was associated with a significant induction of miRNA-1 (162 ± 13%), miRNA-21 (118 ± 6%), and miRNA-24 (46 ± 12%). To test its protective role, miRNA was extracted from 6 hearts following the IPC protocol; and then injected in vivo into the left ventricle wall in another group of 6 mice. Forty-eight hrs later, these mice were subjected to I/R injury in vivo by left coronary artery ligation for 30 min followed by reperfusion for 24 hr. In addition, a subset of mice was treated with miRNA inhibitors (methylated antisense miRNA) in conjunction with miRNA from IPC hearts. The results show that miRNA extracted from the IPC hearts reproduced a protective phenotype with significantly lower infarction (18.8 ± 2.5 %) in vivo as compared to saline-treated control (37.5 ± 2.2%). This protective effect was totally abolished by specific inhibitors of miRNA-1 and miRNA-21 (IS: 43.7 ± 2.1%). CONCLUSION : miRNA extracted from preconditioned hearts shows a protective role against I/R injury. The detection of miRNA in preconditioned hearts offers a novel strategy in cardioprotection. Further studies are needed to identify the gene targets by which miRNA generate protective phenotype.

scholarly journals Effects of Dantrolene on Arrhythmogenicity in Isolated Regional Ischemia-Reperfusion Rabbit Hearts with or without Pacing-Induced Heart Failure

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Chung-Chuan Chou ◽  
Hui-Ling Lee ◽  
Po-Cheng Chang ◽  
Hung-Ta Wo ◽  
Ming-Shien Wen ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ischemia Reperfusion ◽  
Rabbit Model ◽  
Control Group ◽  
Ventricular Premature Beat ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Regional Ischemia ◽  
Intracellular Ca

Dantrolene was reported to suppress ventricular fibrillation (VF) in failing hearts with acute myocardial infarction, but its antiarrhythmic efficacy in regional ischemia-reperfusion (IR) hearts remains debatable. Heart failure (HF) was induced by right ventricular pacing. The IR rabbit model was created by coronary artery ligation for 30 min, followed by reperfusion for 15 min in vivo in both HF and non-HF groups (n= 9 in each group). Simultaneous voltage and intracellular Ca2+(Cai) optical mapping was then performed in isolated Langendorff-perfused hearts. Electrophysiological studies were conducted and VF inducibility was evaluated by dynamic pacing. Dantrolene (10 μM) was administered after baseline studies. The HF group had a higher VF inducibility than the control group. Dantrolene had both antiarrhythmic (prolonged action potential duration (APD) and effective refractory period) and proarrhythmic effects (slowed conduction velocity, steepened APD restitution slope, and enhanced arrhythmogenic alternans induction) but had no significant effects on ventricular premature beat (VPB) suppression and VF inducibility in both groups. A higher VF conversion rate in the non-HF group was likely due to greater APD prolonging effects in smaller hearts compared to the HF group. The lack of significant effects on VPB suppression by dantrolene suggests that triggered activity might not be the dominant mechanism responsible for VPB induction in the IR model.

scholarly journals Possible Role of Interaction between PPARαand Cyclophilin D in Cardioprotection of AMPK againstIn VivoIschemia-Reperfusion in Rats

PPAR Research ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Giselle Barreto-Torres ◽  
Sabzali Javadov
Keyword(s):  
Cardiac Function ◽  
Mitochondrial Function ◽  
Mitochondrial Permeability Transition ◽  
Synergistic Effects ◽  
Ischemia Reperfusion ◽  
Protective Effects ◽  
Simultaneous Administration ◽  
Cyclophilin D ◽  
Ptp Opening

Activated AMPK protects the heart from cardiac ischemia-reperfusion (IR) injury and is associated with inhibition of mitochondrial permeability transition pore (PTP) opening. On the other hand, pharmacological inhibition of the PTP reduces infarct size and improves cardiac function. However, it is unclear whether beneficial effects of AMPK are mediated through the PTP and, if they are not, whether simultaneous activation of AMPK and inhibition of the PTP exert synergistic protective effects against cardiac IR injury. Here, we examined the effects of the AMPK activator, A-769662 in combination with the PTP inhibitor, sanglifehrin A (SfA) onin vivocardiac IR. Cardiac dysfunction following IR injury was associated with decreased activity of the mitochondrial electron transport chain (ETC) and increased mitochondrial ROS and PTP opening. Administration of A-769662 or SfA individually upon reperfusion improved cardiac function, reduced infarction size, and inhibited ROS production and PTP opening. However, simultaneous administration of SfA and A-769662 did not provide synergistic improvement of postischemic recovery of cardiac and mitochondrial function, though both compounds disrupted IR-induced interaction between PPARαand CyP-D. In conclusion, A-769662 or SfA prevents PPARαinteraction with CyP-D, improving cardiac outcomes and increasing mitochondrial function, and simultaneous administration of the drugs does not provide synergistic effects.

α2-Adrenergic stimulation is protective against ischemia-reperfusion-induced ventricular arrhythmias in vivo

2002 ◽  
Vol 283 (6) ◽  
pp. H2606-H2611 ◽  
Author(s):  
John J. Cai ◽  
Donald A. Morgan ◽  
William G. Haynes ◽  
James B. Martins ◽  
Hon-Chi Lee
Keyword(s):  
Sympathetic Nerve ◽  
Ventricular Arrhythmias ◽  
Ischemia Reperfusion ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Renal Sympathetic Nerve ◽  
Arterial Blood ◽  
Adrenergic Antagonist ◽  
Renal Sympathetic

We previously reported that α2-adrenergic receptor (α2-AR) stimulation in Purkinje fibers in vitro prolongs action potential duration and suppresses β-adrenergic-induced delayed afterdepolarizations and sustained triggered activities. We examined the effects of α2-AR stimulation on reperfusion-induced ventricular arrhythmias [ventricular tachycardia/ventricular fibrillation (VT/VF)] in vivo. Arterial blood pressure, heart rate, surface electrocardiogram, and renal sympathetic nerve activities were recorded simultaneously in Sprague-Dawley rats. The incidence of VT/VF was 87.5% for controls, 50% for the β-blocker group, 72% for the α1-blocker group, and 12.5% for the α1 + β-blockers group (unopposed α2-adrenergic activation). Direct α2-AR stimulation with UK-14304 also prevented VT/VF. These effects were reversed by the α2-adrenergic antagonist yohimbine. Increases in renal sympathetic nerve activity were associated with left anterior descending coronary artery ligation and reperfusion (33 ± 1.5 and 62 ± 1.7% over baseline, respectively) in controls. Similar patterns were observed among all experimental groups irrespective of the incidence of VT/VF on reperfusion. We conclude that α2-AR stimulation has a potent antiarrhythmic effect on ischemia-reperfusion-induced VT/VF in vivo and that this effect is not centrally mediated.

scholarly journals Cyclophilin D and the mitochondrial permeability transition in kidney proximal tubules after hypoxic and ischemic injury

2011 ◽  
Vol 301 (1) ◽  
pp. F134-F150 ◽  
Author(s):  
Jeong Soon Park ◽  
Ratna Pasupulati ◽  
Thorsten Feldkamp ◽  
Nancy F. Roeser ◽  
Joel M. Weinberg
Keyword(s):  
Proximal Tubule ◽  
Mitochondrial Permeability Transition ◽  
Ischemia Reperfusion ◽  
Subsequent Development ◽  
Permeability Transition ◽  
Nonesterified Fatty Acid ◽  
Cyclophilin D ◽  
Mitochondrial Permeability ◽  
Wide Range

Mitochondrial matrix cyclophilin D (CyPD) is known to promote development of the mitochondrial permeability transition (MPT). Kidney proximal tubule cells are especially prone to deleterious effects of mitochondrial damage because of their dependence on oxidative mitochondrial metabolism for ATP production. To clarify the role of CyPD and the MPT in proximal tubule injury during ischemia-reperfusion (I/R) and hypoxia-reoxygenation (H/R), we assessed freshly isolated tubules and in vivo injury in wild-type (WT) and Ppif−/− CyPD-null mice. Isolated mouse tubules developed a sustained, nonesterified fatty acid-mediated energetic deficit after H/R in vitro that could be substantially reversed by delipidated albumin and supplemental citric acid cycle substrates but was not modified by the absence of CyPD. Susceptibility of WT and Ppif−/− tubules to the MPT was increased by H/R but was less in normoxic and H/R Ppif−/− than WT tubules. Correction of the energetic deficit that developed during H/R strongly increased resistance to the MPT. Ppif−/− mice were resistant to I/R injury in vivo spanning a wide range of severity. The data clarify involvement of the MPT in oxygen deprivation-induced tubule cell injury by showing that the MPT does not contribute to the initial bioenergetic deficit produced by H/R but the deficit predisposes to subsequent development of the MPT, which contributes pathogenically to kidney I/R injury in vivo.

scholarly journals Mechanisms of ranolazine pretreatment in preventing ventricular tachyarrhythmias in diabetic db/db mice with acute regional ischemia–reperfusion injury

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chung-Chuan Chou ◽  
Hui-Ling Lee ◽  
Gwo-Jyh Chang ◽  
Hung-Ta Wo ◽  
Tzung-Hai Yen ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Molecular Mechanisms ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Coronary Artery Ligation ◽  
Ventricular Tachyarrhythmias ◽  
Artery Ligation ◽  
Electrophysiological Studies ◽  
Myocardial Ischemia Reperfusion

AbstractStudies have demonstrated that diabetic (db/db) mice have increased susceptibility to myocardial ischemia–reperfusion (IR) injury and ventricular tachyarrhythmias (VA). We aimed to investigate the antiarrhythmic and molecular mechanisms of ranolazine in db/db mouse hearts with acute IR injury. Ranolazine was administered for 1 week before coronary artery ligation. Diabetic db/db and control db/+ mice were divided into ranolazine-given and -nongiven groups. IR model was created by 15-min left coronary artery ligation and 10-min reperfusion. In vivo electrophysiological studies showed that the severity of VA inducibility was higher in db/db mice than control (db/ +) mice. Ranolazine suppressed the VA inducibility and severity. Optical mapping studies in Langendorff-perfused hearts showed that ranolazine significantly shortened action potential duration, Cai transient duration, Cai decay time, ameliorated conduction inhomogeneity, and suppressed arrhythmogenic alternans induction. Western blotting studies showed that the expression of pThr17-phospholamban, calsequestrin 2 and voltage-gated sodium channel in the IR zone was significantly downregulated in db/db mice, which was ameliorated with ranolazine pretreatment and might play a role in the anti-arrhythmic actions of ranolazine in db/db mouse hearts with IR injury.

Mechanisms of Ranolazine Pretreatment in Preventing Ventricular Tachyarrhythmias in Diabetic db/db Mice with Acute Regional Ischemia-Reperfusion Injury

2020 ◽  
Author(s):  
Chung-Chuan Chou ◽  
Hui-Ling Lee ◽  
Gwo-Jyh Chang ◽  
Hung-Ta Wo ◽  
Tzung-Hai Yen ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Decay Time ◽  
Molecular Mechanisms ◽  
Optical Mapping ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Coronary Artery Ligation ◽  
Ventricular Tachyarrhythmias ◽  
Artery Ligation

Abstract Background: Studies have demonstrated that db/db mice have increased susceptibility to myocardial ischemia-reperfusion (IR) injury and ventricular tachyarrhythmias (VA). We aimed to investigate the antiarrhythmic and molecular mechanisms of ranolazine in db/db mouse hearts with acute IR injury.Methods: Ranolazine was administered for 1 week before coronary artery ligation. Diabetic db/db and control db/+ mice were divided into ranolazine-given and -nongiven groups. IR model was created by 15-min left coronary artery ligation and 10-min reperfusion. In vivo electrophysiological studies and optical mapping to simultaneously record intracellular Ca2+ (Cai) and membrane voltage in Langendorff-perfused hearts were performed. Western blotting and whole-cell patch clamp study were performed to evaluate the effect of ranolazine in the non-IR and IR zones. Results: The severity of VA inducibility by burst pacing was higher in db/db mice than db/+ mice with acute IR injury. Ranolazine suppressed VA inducibility and severity in db/db and db/+ mice. Optical mapping studies showed that ranolazine significantly shortened action potential duration (APD80), Cai transient duration (CaiTD80), Cai decay time, ameliorated conduction inhomogeneity, and suppressed arrhythmogenic alternans induction. The expression of pThr17-phospholamban, calsequestrin 2 and SCN5A in the IR zone was significantly downregulated in db/db mice, which was ameliorated by ranolazine. Conclusions: Ranolazine pretreatment shortens APD80 and CaiTD80, reduces Cai decay time, and ameliorates conduction velocity inhomogeneity to suppress induction of arrhythmogenic alternans and VA; and amelioration of downregulation of pThr17-phospholamban, calsequestrin 2 and SCN5A may partly underlie the anti-arrhythmic molecular mechanisms of ranolazine in db/db mouse hearts with IR injury.

Delayed expression of cytokines after reperfused myocardial infarction: possible trigger for cardiac dysfunction and ventricular remodeling

2007 ◽  
Vol 293 (5) ◽  
pp. H3014-H3019 ◽  
Author(s):  
Cécile Moro ◽  
Marie-Gabrielle Jouan ◽  
Andry Rakotovao ◽  
Marie-Claire Toufektsian ◽  
Olivier Ormezzano ◽  
...  
Keyword(s):  
Cardiac Dysfunction ◽  
Ventricular Remodeling ◽  
Heart Function ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Cellular Mechanisms ◽  
Artery Ligation ◽  
Tnf Α

Previous studies have shown that 1 wk after permanent coronary artery ligation in rats, some cellular mechanisms involving TNF-α occur and contribute to the development of cardiac dysfunction and subsequent heart failure. The aim of the present study was to determine whether similar phenomena also occur after ischemia-reperfusion and whether cytokines other than TNF-α can also be involved. Anesthetized male Wistar rats were subjected to 1 h coronary occlusion followed by reperfusion. Cardiac geometry and function were assessed by echocardiography at days 5, 7, 8, and 10 postligation. Before death, heart function was assessed in vivo under basal conditions, as well as after volume overload. Finally, hearts were frozen for histoenzymologic assessment of infarct size and remodeling. The profile of cardiac cytokines was determined by ELISA and ChemiArray on heart tissue extracts. As expected, ischemia-reperfusion induced a progressive remodeling of the heart, characterized by left ventricular free-wall thinning and cavity dilation. Heart function was also decreased in ischemic rats during the first week after surgery. Interestingly, a transient and marked increase in TNF-α, IL-1β, IL-6, cytokine-induced neutrophil chemoattractant (CINC) 2, CINC3, and macrophage inflammatory protein-3α was also observed in the myocardium of myocardial ischemia (MI) animals at day 8, whereas the expression of anti-inflammatory interleukins IL-4 and IL-10 remained unchanged. These results suggest that overexpression of proinflammatory cytokines occurring during the first week after ischemia-reperfusion may play a role in the adaptative process in the myocardium and contribute to early dysfunction and remodeling.

scholarly journals Activation of the oxygen-sensing signal cascade prevents mitochondrial injury after mouse liver ischemia-reperfusion

2008 ◽  
Vol 295 (4) ◽  
pp. G823-G832 ◽  
Author(s):  
Zhi Zhong ◽  
Venkat K. Ramshesh ◽  
Hasibur Rehman ◽  
Robert T. Currin ◽  
Vijayalakshmi Sridharan ◽  
...  
Keyword(s):  
Mitochondrial Permeability Transition ◽  
Oxygen Sensing ◽  
Ischemia Reperfusion ◽  
Multiphoton Microscopy ◽  
Specific Inhibitor ◽  
Permeability Transition ◽  
Heme Oxygenase 1 ◽  
Mitochondrial Depolarization ◽  
Signal Cascade

The mitochondrial permeability transition (MPT) plays an important role in hepatocyte death caused by ischemia-reperfusion (IR). This study investigated whether activation of the cellular oxygen-sensing signal cascade by prolyl hydroxylase inhibitors (PHI) protects against the MPT after hepatic IR. Ethyl 3,4-dihyroxybenzoate (EDHB, 100 mg/kg ip), a PHI, increased mouse hepatic hypoxia-inducible factor-1α and heme oxygenase-1 (HO-1). EDHB-treated and untreated mice were subjected to 1 h of warm ischemia to ∼70% of the liver followed by reperfusion. Mitochondrial polarization, cell death, and the MPT were assessed by intravital confocal/multiphoton microscopy of rhodamine 123, propidium iodide, and calcein. EDHB largely blunted alanine aminotransferase (ALT) release and necrosis after reperfusion. In vehicle-treated mice at 2 h after reperfusion, viable cells with depolarized mitochondria were 72%, and dead cells were 2%, indicating that depolarization preceded necrosis. Mitochondrial voids excluding calcein disappeared, indicating MPT onset in vivo. NIM811, a specific inhibitor of the MPT, blocked mitochondrial depolarization after IR, further confirming that mitochondrial depolarization was due to MPT onset. EDHB decreased mitochondrial depolarization to 16% and prevented the MPT. Tin protoporphyrin (10 μmol/kg sc), an HO-1 inhibitor, partially abrogated protection by EDHB against ALT release, necrosis, and mitochondrial depolarization. In conclusion, IR causes the MPT and mitochondrial dysfunction, leading to hepatocellular death. PHI prevents MPT onset and liver damage through an effect mediated partially by HO-1.

Abstract P237: Is Ischemia/Reperfusion an Efficient Method for Producing Heart Failure in Rats?

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Ana Carolina M Omoto ◽  
Fábio N Gava ◽  
Mauro de Oliveira ◽  
Carlos A Silva ◽  
Rubens Fazan ◽  
...  
Keyword(s):  
Heart Failure ◽  
Diastolic Pressure ◽  
Histopathological Examination ◽  
Ischemia Reperfusion ◽  
Mitral Annulus ◽  
Mortality Rates ◽  
Tissue Doppler ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Artery Ligation

Myocardium infarction (MI) elicited by coronary artery ligation (CAL) is commonly used to induce chronic heart failure (HF) in rats. However, CAL shows high mortality rates. Given that ischemia-reperfusion (IR) may cause the development of HF, this approach may be useful for obtaining a model of HF with low mortality rates. Therefore, it was compared the model of CAL vs. IR in rats, evaluating the mortality and cardiac morphological and functional aspects. The IR consisted of 30 minutes of cardiac ischemia. Wistar rats were assigned into three groups: CAL: n=18; IR: n=7; SHAM (fictitious IR): n=7. After four weeks of CAL, the subjects were evaluated by echocardiography and ventriculography as well. The statistical analysis consisted of ANOVA combined with Tukey’s posthoc test (p<0.05). There were no deaths in the IR and SHAM groups, whereas in the CAL group the mortality rate was 33.33% (6 out of 18). In the CAL group echocardiography showed increased left ventricular (LV) cavity during systole (8.3 ± 1mm) and diastole (10.5 ± 1mm); decreased LV free wall during systole (1.4 ± 0.5 mm); increased left atrium/aorta (2.3 ± 0.4) ratio. These changes were not significant in IR (4.8 ± 0.5mm, 7.6 ± 0.6mm, 2.6 ± 0.3 mm, 1.6 ± 0.2) and SHAM (4.6 ± 0.6 mm, 7.7 ± 0.8mm, 2.8 ± 0.4mm, 1.5 ± 0.2) groups. There was also the reduction in the ejection fraction in the CAL group (41 ± 12 %) when compared with IR (65 ± 9%) and SHAM (69 ± 7%) groups. The tissue Doppler analysis from the lateral mitral annulus showed reduction in E′ in CAL (-29 ± 8 mm/s) and IR (-31± 9 mm/s) groups when compared with the SHAM (-48 ± 11 mm/s) group. The ventriculography in the CAL group showed smaller maximum dP/dt (6519 ± 1062) and greater end-diastolic pressure (33 ± 8 mmHg) when compared with IR (8716 ± 756 mmHg/s; 9 ± 9 mmHg) and SHAM (7989 ± 1230 mmHg/s; 9 ± 7 mmHg) groups. The CAL group presented transmural infarct size of 40% of the left ventricular wall, measured under histopathological examination. In conclusion, IR for 30 minutes caused only small changes in LV diastolic function, assessed by tissue Doppler; however, the IR was not effective for promoting HF, as observed with CAL. Thus, it is possible that prolonged IR is necessary for promoting significant HF in rats.

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