Hemodynamic Effects of Strontium Chloride in Acute Experimental Myocardial Infarction

1974 ◽  
Vol 52 (5) ◽  
pp. 920-929 ◽  
Author(s):  
Pierre Côté ◽  
Donald C. Harrison
Keyword(s):  
Myocardial Infarction ◽  
Left Atrial ◽  
Aortic Pressure ◽  
Left Ventricular ◽  
Experimental Myocardial Infarction ◽  
Coronary Artery Ligation ◽  
Strontium Chloride ◽  
Hemodynamic Effects ◽  
Artery Ligation ◽  
Mean Aortic Pressure

The hemodynamic effects of strontium chloride infused intravenously were compared with the effects of calcium chloride in dogs with infarction produced by coronary artery ligation. Strontium improved the circulatory depression resulting from the experimental myocardial infarction. These effects were manifested by a 49% peak increase in the first derivative of left ventricular pressure (dp/dt), 74% in cardiac output, a significant although transient decrease in left atrial pressure of 13%, and a marked drop of 40% in systemic vascular resistance. Mean aortic pressure increased by 18% during the first half of the infusion, and thereafter returned toward the control value. The 31% decrease in heart rate is probably secondary to the overall improvement in cardiac function. Calcium in approximately one-half the amount of strontium was infused during the same length of time to a different group of animals with depression of venticular function by coronary artery ligation. Similar hemodynamic responses occurred during calcium infusion, but were of greater magnitude in left ventricular dp/dt and left atrial pressure, these changes being respectively +117 and −32%. However, the effects on heart rate and systemic vascular resistances were similar, −22% and −42%, respectively. Mean aortic pressure increased less in the calcium group. Strontium has beneficial circulatory effects in depressed ventricular function produced by infarction in dogs.

Targeted deletion of MMP-2 attenuates early LV rupture and late remodeling after experimental myocardial infarction

2003 ◽  
Vol 285 (3) ◽  
pp. H1229-H1235 ◽  
Author(s):  
Shunji Hayashidani ◽  
Hiroyuki Tsutsui ◽  
Masaki Ikeuchi ◽  
Tetsuya Shiomi ◽  
Hidenori Matsusaka ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Left Ventricular ◽  
Experimental Myocardial Infarction ◽  
Matrix Metalloproteinase 2 ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Targeted Deletion ◽  
Arterial Blood ◽  
Lv Remodeling

Matrix metalloproteinase-2 (MMP-2) is prominently overexpressed both after myocardial infarction (MI) and in heart failure. However, its pathophysiological significance in these conditions is still unclear. We thus examined the effects of targeted deletion of MMP-2 on post-MI left ventricular (LV) remodeling and failure. Anterior MI was produced in 10- to 12-wk-old male MMP-2 knockout (KO) and sibling wild-type (WT) mice by ligating the left coronary artery. By day 28, MI resulted in a significant increase in mortality in association with LV cavity dilatation and dysfunction. The MMP-2 KO mice had a significantly better survival rate than WT mice (56% vs. 85%, P < 0.05), despite a comparable infarct size (50 ± 3% vs. 51 ± 3%, P = not significant), heart rate, and arterial blood pressure. The KO mice had a significantly lower incidence of LV rupture (10% vs. 39%, P < 0.05), which occurred within 7 days of MI. The KO mice exerted less LV cavity dilatation and improved fractional shortening after MI by echocardiography. The LV zymographic MMP-2 level significantly increased in WT mice after coronary artery ligation; however, this was completely prevented in KO mice. In contrast, the increase in the LV zymographic MMP-9 level after MI was similar between KO and WT mice. MMP-2 activation is therefore considered to contribute to an early cardiac rupture as well as late LV remodeling after MI. The inhibition of MMP-2 activation may therefore be a potentially useful therapeutic strategy to manage post-MI hearts.

Abstract 14122: Myeloid Cell mPGES-1 Depletion Attenuates Mortality After Myocardial Infarction in Mice

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Lihong Chen ◽  
Guangrui Yang ◽  
Garret FitzGerald
Keyword(s):  
Myocardial Infarction ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Left Ventricular ◽  
Experimental Myocardial Infarction ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Treatment And Prevention

Selective depletion of microsomal PGE2 synthase (mPGES) -1 in myeloid cells retards atherogenesis and suppresses the vascular proliferative response to injury, while it does not predispose to thrombogenesis or hypertension. However, studies using bone marrow transplants from irradiated mice suggest that myeloid cell mPGES-1 facilitates cardiac remodeling and prolongs survival after experimental myocardial infarction (MI). Here we addressed this question using mice lacking mPGES-1 in myeloid cells, particularly macrophages (Mac-mPGES-1 KO), generated by crossing mPGES-1 floxed mice with LysMCre mice, and subjecting them to coronary artery ligation. Cardiac structure and function were assessed by morphometric analysis, echocardiography, and invasive hemodynamics 7 and 28 days after MI. Despite a similar infarct size, in contrast to the prior report, the post-MI survival rate was markedly improved in the Mac-mPGES-1 KO mice compared to WT controls (92.9% vs. 55.6%, p=0.03). Left ventricular systolic (reflected by ejection fraction, fractional shortening, end systolic pressure, and +dP/dt) and diastolic function (reflected by end diastolic pressure, -dP/dt, and Tau), cardiac hypertrophy (reflected by LV dimensions) and staining for fibrosis did not differ between the groups. In conclusion, Cre-loxP mediated deletion of mPGES-1 in myeloid cells has favorable effects on post-MI survival, with no detectable adverse influence on post-MI remodeling. These results add to evidence that targeting macrophage mPGES-1 may represent a safe and efficacious approach to the treatment and prevention of cardiovascular inflammatory disease.

Cardiac adaptations to endurance training in rats with a chronic myocardial infarction

1989 ◽  
Vol 66 (2) ◽  
pp. 712-719 ◽  
Author(s):  
T. I. Musch ◽  
R. L. Moore ◽  
P. G. Smaldone ◽  
M. Riedy ◽  
R. Zelis
Keyword(s):  
Myocardial Infarction ◽  
Endurance Training ◽  
Left Ventricular ◽  
Treadmill Running ◽  
Coronary Artery Ligation ◽  
Maximal Heart Rate ◽  
Chronic Myocardial Infarction ◽  
Artery Ligation ◽  
Training Paradigm ◽  
Myosin Isozyme

The hemodynamic response to maximal exercise was determined in sedentary and trained rats with a chronic myocardial infarction (MI) produced by coronary artery ligation and in rats that underwent sham operations (SHAM). Infarct size in the MI groups of rats comprised 28–29% of the total left ventricle and resulted in both metabolic and hemodynamic changes that suggested that these animals had moderate compensated heart failure. The training regimen used in the present study produced significant increases in maximal O2 uptake (VO2max) when expressed in absolute terms (ml/min) or when normalized for body weight (ml.min-1.kg-1) and consisted of treadmill running at work loads that were equivalent to 70–80% of the animal's VO2max for a period of 60 min/day, 5 days/wk over an 8- to 10-wk interval. This training paradigm produced two major cardiocirculatory adaptations in the MI rat that had not been elicited previously when using a training paradigm of a lower intensity. First, the decrement in the maximal heart rate response to exercise (known as “chronotropic incompetence”) found in the sedentary MI rat was completely reversed by endurance training. Second, the downregulation of cardiac myosin isozyme composition from the fast ATPase V1 isoform toward the slower ATPase (V2 and V3) isoforms in the MI rat was partially reversed by endurance training. These cardiac adaptations occurred without a significant increase in left ventricular pump function as an increase in maximal cardiac output (Qmax) and maximal stroke volume (SVmax) did not occur in the trained MI rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of Myocardial Infarction with Sequential Ligation of the Left Anterior Descending Artery and Its Diagonal Branch in Dogs and Sheep

2003 ◽  
Vol 26 (4) ◽  
pp. 351-357 ◽  
Author(s):  
W.G. Kim ◽  
Y.C. Shin ◽  
S.W. Hwang ◽  
C. Lee ◽  
C.Y. Na
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Pulmonary Artery ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Suitable Model ◽  
Artery Ligation ◽  
Diagonal Branch ◽  
Left Anterior Descending Artery ◽  
Arterial Blood

We report a comparison of the effects of myocardial infarction in dogs and sheep using sequential ligation of the left anterior descending artery (LAD) and its diagonal branch (DA), with hemodynamic, ultrasonographic and pathological evaluations. Five animals were used in each group. After surgical preparation, the LAD was ligated at a point approximately 40% of the distance from the apex to the base of the heart, and after one hour, the DA was ligated at the same level. Hemodynamic and ultrasonographic measurements were performed preligation, 30 minutes after LAD ligation, and 1 hour after DA ligation. As a control, two animals in each group were used for the simultaneous ligation of the LAD and the DA. Two months after the coronary ligation, the animals were evaluated as previously, and killed for postmortem examination of their hearts. All seven animals in the dog group survived the experimental procedures, while in the sheep group only animals with sequential ligation of the LAD and DA survived. Statistically significant decreases in systemic arterial blood pressure and cardiac output, and an increase in the pulmonary artery capillary wedge pressure (PACWP) were observed one hour after sequential ligation of the LAD and its DA in the sheep, while only systemic arterial pressures decreased in the dog. Ultrasonographic analyses demonstrated variable degrees of anteroseptal dyskinesia and akinesia in all sheep, but in no dogs. Data two months after coronary artery ligation showed significant increases in central venous pressure, pulmonary artery pressure, and PACWP in the sheep, but not in the dog. Left ventricular end-diastolic dimension and left ventricular end-systolic dimension in ultrasonographic studies were also increased only in the sheep. Pathologically, the well-demarcated thin-walled transmural anteroseptal infarcts with chamber enlargement were clearly seen in all specimens of sheep, and only-mild-to-moderate chamber enlargements with endocardial fibrosis were observed in the dog hearts. In conclusion, this study confirms that the dog is not a suitable model for myocardial infarction with failure by coronary artery ligation despite negligent operative mortality, when compared directly with an ovine model.

scholarly journals Progression of heart failure after myocardial infarction in the rat

2001 ◽  
Vol 281 (5) ◽  
pp. R1734-R1745 ◽  
Author(s):  
J. Francis ◽  
R. M. Weiss ◽  
S. G. Wei ◽  
A. K. Johnson ◽  
R. B. Felder
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Ventricular Remodeling ◽  
Systolic Function ◽  
Left Ventricular Remodeling ◽  
Plasma Renin ◽  
Left Ventricular Systolic Function ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Artery Ligation

This study examined the early neurohumoral events in the progression of congestive heart failure (CHF) after myocardial infarction (MI) in rats. Immediately after MI was induced by coronary artery ligation, rats had severely depressed left ventricular systolic function and increased left ventricular end-diastolic volume (LVEDV). Both left ventricular function and the neurohumoral indicators of CHF underwent dynamic changes over the next 6 wk. LVEDV increased continuously over the study interval, whereas left ventricular stroke volume increased but reached a plateau at 4 wk. Plasma renin activity (PRA), arginine vasopressin, and atrial natriuretic factor all increased, but with differing time courses. PRA declined to a lower steady-state level by 4 wk. Six to 8 wk after MI, CHF rats had enhanced renal sympathetic nerve activity and blunted baroreflex regulation. These findings demonstrate that the early course of heart failure is characterized not by a simple “switching on” of neurohumoral drive, but rather by dynamic fluctuations in neurohumoral regulation that are linked to the process of left ventricular remodeling.

Bradykinin metabolism in rat hearts with left-ventricular hypertrophy following myocardial infarction

2003 ◽  
Vol 81 (7) ◽  
pp. 740-746 ◽  
Author(s):  
Marie-Josée Dumoulin ◽  
Albert Adam ◽  
Jean-Lucien Rouleau ◽  
Hugues Gosselin ◽  
Daniel Lamontagne
Keyword(s):  
Myocardial Infarction ◽  
Left Ventricular Hypertrophy ◽  
Ventricular Hypertrophy ◽  
Neutral Endopeptidase ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Relative Contribution ◽  
The Difference ◽  
Level Of Significance

The aim of the present study was to assess the contribution of angiotensin I converting enzyme (ACE) and neutral endopeptidase (NEP) in the coronary degradation of bradykinin (BK) after left-ventricular hypertrophy following myocardial infarction (MI) in rats. Myocardial infarction was induced by left descendant coronary artery ligation, and the contribution of ACE and NEP in the degradation of exogenous BK after a single passage through the coronary bed was assessed at 2, 5, and 36 days post-MI. BK degradation rate (Vmax/Km) was found to be significantly lower in hearts at 36 days (3.30 ± 0.28 min–1) compared with 2 days (4.39 ± 0.32 min–1) for noninfarcted hearts, but this reduction was just above the statistical level of significance for post-MI hearts. In infarcted hearts, Vmax/Km was increased significantly 5 days post-MI (4.91 ± 0.28 min–1) compared with the 2 and 36 day-groups (3.43 ± 0.20 and 2.78 ± 0.16 min–1, respectively). The difference between noninfarcted and MI was significant only 2 days post-MI. Treatment with the vasopeptidase inhibitor, omapatrilat, showed that the relative contribution of ACE and NEP combined increased over time in infarcted hearts and became significantly higher 36 versus 2 days post-MI. Finally, the treatment with an ACE inhibitor (enalaprilat) and a NEP inhibitor (retrothiorphan) in the 36-day infarcted and noninfarcted hearts showed that the relative contribution of ACE in infarcted hearts was comparable with that of noninfarcted hearts, whereas the relative contribution of NEP was increased significantly in infarcted hearts. In conclusion, experimental MI in rats induces complex changes in the metabolism of exogenous BK. The changes resulted in an increased relative contribution of NEP 36 days after infarction.Key words: bradykinin, ACE, NEP, myocardial infarction.

scholarly journals Nitroxides Mitigate Neutrophil-Mediated Damage to the Myocardium after Experimental Myocardial Infarction in Rats

2020 ◽  
Vol 21 (20) ◽  
pp. 7650
Author(s):  
Mary El Kazzi ◽  
Han Shi ◽  
Sally Vuong ◽  
Xiaosuo Wang ◽  
Belal Chami ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Hypochlorous Acid ◽  
Immune Cell ◽  
Reperfusion Therapy ◽  
Experimental Myocardial Infarction ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Post Surgery ◽  
Male Wistar Rats ◽  
Oxidant Production

Reperfusion therapy increases survival post-acute myocardial infarction (AMI) while also stimulating secondary oxidant production and immune cell infiltration. Neutrophils accumulate within infarcted myocardium within 24 h post-AMI and release myeloperoxidase (MPO) that catalyses hypochlorous acid (HOCl) production while increasing oxidative stress and inflammation, thereby enhancing ventricular remodelling. Nitroxides inhibit MPO-mediated HOCl production, potentially ameliorating neutrophil-mediated damage. Aim: Assess the cardioprotective ability of nitroxide 4-methoxyTEMPO (4MetT) within the setting of AMI. Methods: Male Wistar rats were separated into 3 groups: SHAM, AMI/R, and AMI/R + 4MetT (15 mg/kg at surgery via oral gavage) and subjected to left descending coronary artery ligation for 30 min to generate an AMI, followed by reperfusion. One cohort of rats were sacrificed at 24 h post-reperfusion and another 28 days post-surgery (with 4MetT (15 mg/kg) administration twice daily). Results: 3-chlorotyrosine, a HOCl-specific damage marker, decreased within the heart of animals in the AMI/R + 4-MetT group 24 h post-AMI, indicating the drug inhibited MPO activity; however, there was no evident difference in either infarct size or myocardial scar size between the groups. Concurrently, MPO, NfκB, TNFα, and the oxidation marker malondialdehyde increased within the hearts, with 4-MetT only demonstrating a trend in decreasing MPO and TNF levels. Notably, 4MetT provided a significant improvement in cardiac function 28 days post-AMI, as assessed by echocardiography, indicating potential for 4-MetT as a treatment option, although the precise mechanism of action of the compound remains unclear.

Abstract 18592: Anti-arrhythmic Effect of a Novel Rycal, S44121 / Arm036, in a Post-myocardial Infarction Mouse Model of Heart Failure

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jerome Thireau ◽  
Charlotte Farah ◽  
Muriel Bouly ◽  
Jerome Roussel ◽  
Alain Lacampagne ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Mouse Model ◽  
Ryanodine Receptors ◽  
Left Ventricular ◽  
Cardiac Contraction ◽  
Post Myocardial Infarction ◽  
Coronary Artery Ligation ◽  
Artery Ligation

Introduction: Targeting leaky cardiac ryanodine receptors (RyR2) to prevent diastolic Ca2+ release from the sarcoplasmic reticulum (SR) is a promising pharmacological approach, to rescue the impaired cardiac contraction and prevent Ca2+-dependent arrhythmias in heart failure (HF) and disease. Hypothesis: Based on prior work from the Marks group, the Rycal S44121 (also known as ARM036) is an experimental small molecule stabilizer of RyR. We investigated the effects of S44121 in a post-myocardial infarction (PMI) mouse model of HF. Methods and results: Mice were randomly assigned to 3 groups: Sham, PMI (subjected to left coronary artery ligation), and PMI-S (treated for 3 weeks with S44121 by subcutaneous osmotic pumps on day 7 post-MI, 10 mg/kg/day). Intracellular Ca2+ was measured on single left ventricular myocytes. PMI mice exhibited a 4-fold increase in the frequency of spontaneous Ca2+ release events, Ca2+ sparks, as measured in quiescent cells using the fluorescent Ca2+ indicator Fluo-4. PMI mice also exhibited higher global diastolic Ca2+, measured with the ratiometric fluorescent probe, Indo-1 AM, and increased the occurrence of ectopic diastolic Ca2+ waves. Acute application of S44121 (10 μM for 15 min) reduced Ca2+ sparks frequency. Chronic treatment of mice with S44121 also normalized the frequency of Ca2+ sparks and of ectopic Ca2+ waves, and corrected diastolic cellular Ca2+ overload. Effects were maximal at 20 mg/kg/day. Furthermore, treatment with S44121 abolished Ca2+ waves promoted by β-adrenergic challenge (acute application of isoproterenol, 10 nM). The potential anti-arrhythmic benefit of S44121 was assessed in vivo using telemetric surface electrocardiograms. S44121 had no effect on ECG intervals and did not alter the heart rate. However, anti-arrhythmic effects were confirmed by observation of a dose-dependent reduction of spontaneous ventricular extrasystoles and ventricular tachycardia. Near maximum benefits were observed at 10 mg/kg/day, both in basal conditions or following a challenge with acute treatment of isoproterenol (0.5 mg/kg, dosed ip). Conclusion: In mice with post-ischemic HF, treatment with S44121 prevented the abnormal diastolic SR Ca2+ leak and ectopic Ca2+ waves, and reduced ventricular arrhythmias.

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