scholarly journals Scar and pulmonary expression and shedding of ACE in rat myocardial infarction

2002 ◽  
Vol 283 (1) ◽  
pp. H156-H164 ◽  
Author(s):  
Roger Gaertner ◽  
Fabrice Prunier ◽  
Monique Philippe ◽  
Liliane Louedec ◽  
Jean-Jacques Mercadier ◽  
...  

We examined the topology of angiotensin-converting enzyme (ACE) mRNA expression, activity, and shedding in myocardial infarction-induced heart failure and sought to elucidate the source of the increased plasma ACE activity in this model. Three months after coronary ligature, lung, scar, and remaining viable left ventricular tissues were analyzed for ACE mRNA expression as well as tissue and solubilized ACE activity. ACE mRNA expression increased in the scar with respect to infarct severity, decreased in the lung, and remained unchanged in the left ventricle. ACE activity decreased in the lung and increased in the scar tissue and plasma. Shedding of ACE remained constant in the lung and increased in the scar. This study shows that ACE expression and activity is shifted from the pulmonary endothelium to the infarct scar tissue and that constancy of shedding in the lung and its increase in the scar are the source of the increased plasma ACE in congestive heart failure.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Joseph Francis ◽  
Li Yu ◽  
Anuradha Guggilam ◽  
Srinivas Sriramula ◽  
Irving H Zucker

3-Hydroxyl-3-methylglutaryl coenzyme A reductase inhibitors (statins) have been shown to reduce the incidence of myocardial infarction independent of their lipid-lowering effects. Nitric oxide (NO) in the central nervous system contributes to cardiovascular regulatory mechanisms. Imbalance between nitric oxide (NO) and superoxide anion (O 2 . − ) in the brain may contribute to enhanced sympathetic drive in heart failure (HF). This study was done to determine whether treatment with atorvastatin (ATS) ameliorates the imbalance between NO and O 2 . − production in the brain stem and contributes to improvement of left ventricular (LV) function. Methods and Results: Myocardial infarction (MI) was induced by ligation of the left coronary artery or sham surgery. Subsequently, mice were treated with ATS (10 μg/kg) (MI + ATS), or vehicle (MI + V). After 5 weeks, echocardiography revealed left ventricular dilatation in MI mice. Realtime RT-PCR indicated an increase in the mRNA expression of the LV hypertrophy markers, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). Neuronal NOS (nNOS) and endothelial NOS (eNOS) mRNA expression were significantly reduced, while that of NAD(P)H oxidase subunit (gp91phox) expression was elevated in the brain stem of MI mice. Compared with sham-operated mice, ATS-treated mice showed reduced cardiac dilatation, decreased ANP and BNP in the LV. ATS also reduced gp91phox expression and increased nNOS mRNA expression in the brain stem, while no changes in eNOS and iNOS were observed. Conclusion: These findings suggest that ATS reduces oxidative stress and increases neuronal NOS in the brain stem, and improves left ventricular function in heart failure.


2009 ◽  
Vol 1 ◽  
pp. CMT.S2095
Author(s):  
M. Khazaei ◽  
AM. Sharifi ◽  
S. Golbidi ◽  
I. Laher

Several clinical studies demonstrate a beneficial role of angiotensin-converting enzyme (ACE) inhibitors in patients with myocardial infarction, hypertension and diabetes mellitus. This review focuses on the effects of ramipril, a weak inhibitor of ACE that is rapidly hydrolyzed to ramiprilat, an active metabolite. The Heart Outcome Prevention Evaluation (HOPE) study evaluated the effects of ramipril in patients with a high risk for cardiovascular events without pre-existing left ventricular dysfunction or heart failure. In this review, we summarized the effects of ramipril on myocardial infarction, death, diabetes mellitus, and stroke.


1993 ◽  
Vol 27 (6) ◽  
pp. 755-766 ◽  
Author(s):  
Christina Beckwith ◽  
Mark A. Munger

OBJECTIVE: To discuss the effects of angiotensin-converting enzyme (ACE) inhibitors on ventricular remodeling and survival after acute myocardial infarction (AMI). An overview is provided of the pathophysiologic changes produced by AMI and the ventricular remodeling process. ACE inhibitors have been studied for their use in the prevention of ventricular remodeling and reduction in postinfarction mortality. Trials in humans and animals are reviewed, including study methods, results, and limitations. DATA SOURCES: MEDLINE searches identified applicable literature, including experimental trials and review articles. STUDY SELECTION: All clinical trials of ACE inhibitors following AMI were reviewed. DATA EXTRACTION: Morbidity and mortality data evaluating the effect of postinfarction ventricular remodeling are rare. At the time of publication, all available clinical trials studying the effects of ACE inhibitors on postinfarction ventricular remodeling were included, regardless of whether morbidity and mortality were assessed. Data from the Survival and Ventricular Enlargement (SAVE) and Cooperative New Scandinavian Enalapril Survival Study II (CONSENSUS II) trials include almost 10000 patients. Data were extracted by two independent observers. Data quality and validity were assessed based on sample size, stratification of study population, and statistical power of the studies. DATA SYNTHESIS: ACE inhibitors may prevent the deleterious consequences of AMI, including ventricular remodeling and neurohumoral activation. Ventricular hypertrophy begins acutely following infarction, an early physiologic response to myocardial injury. Hemodynamic benefits from the initial phase of left ventricular hypertrophy include increased ventricular working capacity, normalized systolic wall stress, and maintenance of stroke volume. Although acute dilatation may delay hemodynamic deterioration for six to eight months, it also results in reduced coronary reserve, decreased ventricular compliance, and altered myocardial contractility. With chronic dilatation, the beneficial effects reach a plateau, stroke volume decreases, contractility is reduced, and cardiac failure may ensue. Ventricular hypertrophy is associated with worsened prognosis following infarction and may be the most important single determinant of late prognosis. Ventricular hypertrophy contributes to postinfarction heart failure, angina, and sudden death. Clinical trials show a beneficial effect of the ACE inhibitor captopril on the prevention of left ventricular dysfunction. Although captopril therapy significantly improved survival and myocardial function following AMI in the SAVE trial, these results cannot be generalized to all patient subpopulations. The CONSENSUS II trial demonstrated a decreased survival rate when enalapril was administered within 24 hours of AMI, indicating that timing of therapy may be an important consideration. Captopril therapy may positively affect outcome when initiated 3–16 days following infarction in patients with ejection fractions below 40 percent and who have no signs of ischemia or heart failure. Based on the CONSENSUS II results, enalapril therapy immediately following AMI cannot be recommended. CONCLUSIONS: Clinical trials have demonstrated that ACE inhibitors can limit ventricular hypertrophy following AMI, resulting in clinical benefit and improved survival. These effects may be secondary to modulation of neurohumoral activation or the antiischemic effect of ACE inhibitors, which may also reduce the incidence of reinfarction. Early intervention with ACE inhibitors (within 3–16 days of infarction) can slow the progression of cardiovascular disease and improve the survival rate.


2019 ◽  
Vol 4 (3) ◽  
pp. 120-123
Author(s):  
Ioana Cîrneală ◽  
Diana Opincariu ◽  
István Kovács ◽  
Monica Chițu ◽  
Imre Benedek

Abstract Heart failure is a clinical syndrome that appears as a consequence of a structural disease, and the most common cause of left ventricular systolic dysfunction results from myocardial ischemia. Cardiac remodeling and neuroendocrine activation are the major compensatory mechanisms in heart failure. The main objective of the study is to identify the association between serum biomarkers illustrating the extent of myocardial necrosis (highly sensitive troponin as-says), left ventricular dysfunction (NT-proBNP), and systemic inflammatory response (illustrated via serum levels of hsCRP and interleukins) during the acute phase of a myocardial infarction, and the left ventricular remodeling process at 6 months following the acute event, quantified via speckle tracking echocardiography. The study will include 400 patients diagnosed with acute myocardial infarction without signs and symptoms of heart failure at the time of enrollment that will undergo a complex clinical examination and speckle tracking echocardiography. Serum samples from the peripheral blood will be collected in order to determine the inflammatory serum biomarkers. After 6 months, patients will be divided into 2 groups according to the development of ventricular remodeling, quantified by speckle tracking echocardiography: group 1 will consist of patients with a remodeling index lower than 15%, and group 2 will consist of patients with a remodeling index higher than 15%. All clinical and imaging data obtained at the baseline will be compared between these two groups in order to determine the features associated with a higher risk of deleterious ventricular remodeling and heart failure.


Author(s):  
С.А. Крыжановский ◽  
И.Б. Цорин ◽  
Е.О. Ионова ◽  
В.Н. Столярук ◽  
М.Б. Вититнова ◽  
...  

Цель исследования - разработка трансляционной модели хронической сердечной недостаточности (ХСН) у крыс, позволяющей, с одной стороны, изучить тонкие механизмы, лежащие в основе данной патологии, а с другой стороны, выявить новые биомишени для поиска и изучения механизма действия инновационных лекарственных средств. Методика. Использован комплекс эхокардиографических, морфологических, биохимических и молекулярно-биологических исследований, позволяющий оценивать и дифференцировать этапы формирования ХСН. Результаты. Динамические эхокардиографические исследования показали, что ХСН формируется через 90 дней после воспроизведения переднего трансмурального инфаркта миокарда. К этому времени у животных основной группы отмечается статистически значимое по сравнению со 2-ми сут. после воспроизведения экспериментального инфаркта миокарда снижение ФВ левого желудочка сердца (соответственно 55,9 ± 1,4 и 63,9 ± 1,6%, р = 0,0008). Снижение насосной функции сердца (на 13% по сравнению со 2-ми сут. после операции и на ~40% по сравнению с интактными животными) сопровождается увеличением КСР и КДР (соответственно с 2,49 ± 0,08 до 3,91 ± 0,17 мм, р = 0,0002, и с 3,56 ± 0,11 до 5,20 ± 0,19 мм, р = 0,0001), то есть к этому сроку развивается сердечная недостаточность. Результаты эхокардиографических исследований подтверждены данными морфометрии миокарда, продемонстрировавшими дилатацию правого и левого желудочков сердца. Параллельно проведенные гистологические исследования свидетельствуют о наличии патогномоничных для данной патологии изменений миокарда (постинфарктный кардиосклероз, компенсаторная гипертрофия кардиомиоцитов, очаги исчезновения поперечной исчерченности мышечных волокон и т.д.) и признаков венозного застоя в легких и печени. Биохимические исследования выявили значимое увеличение концентрации в плазме крови биохимического маркера ХСН - мозгового натрийуретического пептида. Данные молекулярно-биологических исследований позволяют говорить о наличии гиперактивности ренин-ангиотензин-альдостероновой и симпатоадреналовой систем, играющих ключевую роль в патогенезе ХСН. Заключение. Разработана трансляционная модель ХСН у крыс, воспроизводящая основные клинико-диагностические критерии этого заболевания. Показано наличие корреляции между морфометрическими, гистологическими, биохимическими и молекулярными маркерами прогрессирующей ХСН и эхокардиографическими диагностическими признаками, что позволяет использовать неинвазивный метод эхокардиографии, характеризующий состояние внутрисердечной гемодинамики, в качестве основного критерия оценки наличия/отсутствия данной патологии. Aim. Development of a translational model for chronic heart failure (CHF) in rats to identify new biotargets for finding and studying mechanisms of innovative drug effect in this disease. Methods. A set of echocardiographic, morphological, biochemical, and molecular methods was used to evaluate and differentiate stages of CHF development. Results. Dynamic echocardiographic studies showed that CHF developed in 90 days after anterior transmural myocardial infarction. By that time, left ventricular ejection fraction was significantly decreased in animals of the main group compared with rats studied on day 2 after experimental myocardial infarction (55.9 ± 1.4% vs . 63.9 ± 1.6%, respectively, p<0.0008). The decrease in heart’s pumping function (by 13% compared with day 2 after infarction and by approximately 40% compared to intact animals) was associated with increased ESD and EDD (from 2.49 ± 0.08 to 3.91 ± 0.17 mm, p = 0.0002, and from 3.56 ± 0.11 to 5.20 ± 0.19 mm, respectively, p = 0.0001); therefore, heart failure developed by that time. The results of echocardiographic studies were confirmed by myocardial morphometry, which demonstrated dilatation of both right and left ventricles. Paralleled histological studies indicated presence of the changes pathognomonic for this myocardial pathology (postinfarction cardiosclerosis, compensatory hypertrophy of cardiomyocytes, foci of disappeared transverse striation of muscle fibers, etc.) and signs of venous congestion in lungs and liver. Biochemical studies demonstrated a significant increase in plasma concentration of brain natriuretic peptide, a biochemical marker of CHF. Results of molecular studies suggested hyperactivity of the renin-angiotensin-aldosterone and sympathoadrenal systems, which play a key role in the pathogenesis of CHF. Conclusions. A translational model of CHF in rats was developed, which reproduced major clinical and diagnostic criteria for this disease. Morphometric, histological, biochemical, and molecular markers for progressive CHF were correlated with echocardiographic diagnostic signs, which allows using this echocardiographic, noninvasive method characterizing the intracardiac hemodynamics as a major criterion for the presence / absence of this pathology.


Open Heart ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. e001614
Author(s):  
Mohammad R Ostovaneh ◽  
Raj R Makkar ◽  
Bharath Ambale-Venkatesh ◽  
Deborah Ascheim ◽  
Tarun Chakravarty ◽  
...  

BackgroundMost cell therapy trials failed to show an improvement in global left ventricular (LV) function measures after myocardial infarction (MI). Myocardial segments are heterogeneously impacted by MI. Global LV function indices are not able to detect the small treatment effects on segmental myocardial function which may have prognostic implications for cardiac events. We aimed to test the efficacy of allogeneic cardiosphere-derived cells (CDCs) for improving regional myocardial function and contractility.MethodsIn this exploratory analysis of a randomised clinical trial, 142 patients with post-MI with LVEF <45% and 15% or greater LV scar size were randomised in 2:1 ratio to receive intracoronary infusion of allogenic CDCs or placebo, respectively. Change in segmental myocardial circumferential strain (Ecc) by MRI from baseline to 6 months was compared between CDCs and placebo groups.ResultsIn total, 124 patients completed the 6-month follow-up (mean (SD) age 54.3 (10.8) and 108 (87.1%) men). Segmental Ecc improvement was significantly greater in patients receiving CDC (−0.5% (4.0)) compared with placebo (0.2% (3.7), p=0.05). The greatest benefit for improvement in segmental Ecc was observed in segments containing scar tissue (change in segmental Ecc of −0.7% (3.5) in patients receiving CDC vs 0.04% (3.7) in the placebo group, p=0.04).ConclusionsIn patients with post-MI LV dysfunction, CDC administration resulted in improved segmental myocardial function. Our findings highlight the importance of segmental myocardial function indices as an endpoint in future clinical trials of patients with post-MI.Trial registration numberNCT01458405.


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