Gender-specific patterns of left ventricular and myocyte remodeling following myocardial infarction in mice deficient in the angiotensin II type 1a receptor

2005 ◽  
Vol 289 (2) ◽  
pp. H586-H592 ◽  
Author(s):  
Paul Bridgman ◽  
Mark A. Aronovitz ◽  
Rahul Kakkar ◽  
Michael I. Oliverio ◽  
Thomas M. Coffman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Myocardial Infarction ◽  
Infarct Size ◽  
Left Ventricular ◽  
Wild Type ◽  
Lower Systolic Blood Pressure ◽  
Male And Female ◽  
Myocyte Hypertrophy ◽  
Lv Mass ◽  
Gender Specific

Left ventricular (LV) remodeling after myocardial infarction (MI) results from hypertrophy of myocytes and activation of fibroblasts induced, in part, by ligand stimulation of the ANG II type 1 receptor (AT1R). The purpose of the present study was to explore the specific role for activation of the AT1aR subtype in post-MI remodeling and whether gender differences exist in the patterns of remodeling in wild-type and AT1aR knockout (KO) mice. AT1aR-KO mice and wild-type littermates underwent coronary ligation to induce MI or sham procedures; echocardiography and hemodynamic evaluation were performed 6 wk later, and LV tissue was harvested for infarct size determination, morphometric measurements, and gene expression analysis. Survival and infarct size were similar among all male and female wild-type and AT1aR-KO mice. Hemodynamic indexes were also similar except for lower systolic blood pressure in the AT1aR-KO mice compared with wild-type mice. Male and female wild-type and male AT1aR-KO mice developed similar increases in LV chamber size, LV mass corrected for body weight (LV/BW), and myocyte cross-sectional area (CSA). However, female AT1aR-KO mice demonstrated no increase in LV/BW and myocyte CSA post-MI compared with shams. Both male and female wild-type mice demonstrated higher atrial natriuretic peptide (ANP) levels after MI, with female wild types being significantly greater than males. However, male and female AT1aR-KO mice developed no increase in ANP gene expression with MI despite an increase in LV mass and myocyte size in males. These data support that gender-specific patterns of LV and myocyte hypertrophy exist after MI in mice with a disrupted AT1aR gene, and suggest that myocyte hypertrophy post-MI in females relies, in part, on activation of the AT1aR. Further work is necessary to explore the potential mechanisms underlying these gender-based differences.

Abstract 15343: Increasing Left Ventricular Mass is Associated With Greater Microvascular Obstruction During ST-elevation Myocardial Infarction

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Nicole L Bonfig ◽  
Chase R Soukup ◽  
Ross F Garberich ◽  
Sarah J Davidson ◽  
Rose M Peterson ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Infarct Size ◽  
Cardiac Mri ◽  
Microvascular Obstruction ◽  
Myocardial Edema ◽  
Left Ventricular ◽  
St Elevation Myocardial Infarction ◽  
Lv Function ◽  
Lv Mass ◽  
St Elevation

Introduction: The development of microvascular obstruction (MVO) in the setting of ST-Elevation Myocardial Infarction (STEMI) is a powerful predictor of reduced left-ventricular (LV) function, adverse LV remodeling and increased mortality. Although MVO is associated with increasing infarct size and ischemic duration, additional causes of MVO have not been clearly identified. Although MVO may arise from intravascular obstruction from embolization of thrombus, it may also arise from compression of the microvasculature due to increased myocardial edema and extravascular compressive forces. Hypothesis: Because left-ventricular hypertrophy (LVH) is associated with increased extravascular compressive forces, we hypothesized that patients with greater LV mass may be more susceptible to the development of MVO during STEMI. Methods: We measured MVO in 385 patients (59.4 + 12.3 years; 77% male) admitted to our Institution with STEMI who underwent cardiac MRI for measurement of LV function and infarct size following successful primary PCI. A total of 219 patients (57%) had MVO on cardiac MRI measured 1-3 days following PCI of which 172 patients had paired measurements of LV mass. Results: Patients with MVO (13.7 + 13.9 grams) had significantly greater infarct size (54 vs. 31 g; p < 0.001) and LV mass (151 vs 140 g; p<0.01) but reduced LVEF (43.1 vs. 47.8%) despite having similar ischemic times. Among patients with MVO, there was a linear increase in MVO with increasing LV mass (Figure). Conclusions: MVO increases with increasing LV mass and may contribute to the known adverse effects of LVH in STEMI.

Interaction between AT1 and AT2 receptors during postinfarction left ventricular remodeling

2006 ◽  
Vol 290 (3) ◽  
pp. H1004-H1010 ◽  
Author(s):  
Szilard Voros ◽  
Zequan Yang ◽  
Christina M. Bove ◽  
Wesley D. Gilson ◽  
Frederick H. Epstein ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Ejection Fraction ◽  
Infarct Size ◽  
Ventricular Remodeling ◽  
Left Ventricular Remodeling ◽  
Artery Occlusion ◽  
Left Ventricular ◽  
Wild Type ◽  
Systolic Volume ◽  
Myocyte Hypertrophy

The relative contribution of the angiotensin II type 1 and 2 receptors (AT1-R and AT2-R) in postmyocardial infarction (MI) remodeling remains incompletely understood. We studied five groups of C57Bl/6 mice after 1 h of left anterior descending artery occlusion-reperfusion: 1) wild type, untreated ( n = 12); 2) wild type, treated with the AT1-R blocker losartan (10–20 mg·kg−1·day−1 in drinking water) from day 1 to day 28 post-MI ( n = 10); 3) cardiac overexpression of the AT2-R [AT2-transgenic (TG); n = 14]; 4) AT2-TG treated with losartan ( n = 13); and 5) AT2-TG and null for the AT1a-R [AT2-TG/AT1 knockout (KO); n = 10]. Cardiac magnetic resonance imaging (CMR) measured ejection fraction and left ventricular end-diastolic and end-systolic volume (EDVI and ESVI) and mass indexed to weight on days 0, 1, 7, and 28 post-MI. Infarct size was measured on day 1 by late gadolinium-enhanced CMR. Regional myocyte hypertrophy and collagen content were measured on day 28 post-MI. Infarct size was similar among groups. Systolic blood pressure was lowest in AT2-TG/AT1KO. By day 28 post-MI, when corrected for baseline differences, EDVI and ESVI were higher and ejection fraction was lower in wild type than other groups. Ejection fraction was highest and EDVI and mass index were lowest in AT2-TG/AT1KO at day 28. The AT2-TG/AT1KO demonstrated less fibrosis in adjacent regions. Regional myocyte hypertrophy was similar in all groups. The AT1-R and AT2-R are intricately intertwined in post-MI remodeling. Pharmacological blockade of AT1-R is equivalent to AT2-R overexpression in attenuating post-MI remodeling. Genetic knockout of the AT1a-R is additive to AT2-R overexpression, due, at least in part, to blood pressure lowering.

scholarly journals Cardioprotective effects of Ginsenoside compound-Mc1 and Dendrobium Nobile Lindl against myocardial infarction in an aged rat model: Involvement of TLR4/NF-κB signaling pathway

2021 ◽  
Vol 19 ◽  
pp. 205873922110005
Author(s):  
Yongle Sun ◽  
Jing Geng ◽  
Deyu Wang
Keyword(s):  
Myocardial Infarction ◽  
Combination Therapy ◽  
Infarct Size ◽  
Signaling Pathway ◽  
Left Ventricular ◽  
Male Rats ◽  
Dendrobium Nobile ◽  
Tnf Α ◽  
Cardioprotective Effects ◽  
Dendrobium Nobile Lindl

Aging is the crucial co-morbidity that prevents the full cardioprotection against myocardial ischemia/reperfusion (I/R) injury. Combination therapy as a promising strategy may overcome this clinical problem. This study aimed to investigate the cardioprotective effects of Ginsenoside compound-Mc1 (GMc1) and Dendrobium Nobile Lindl (DNL) in myocardial I/R injury and explore the involvement of the TLR4/NF-κB signaling pathway in aged rats. In vivo I/R injury and myocardial infarction was established by temporary coronary ligation in 22–24 months’ old Sprague Dawley male rats. GMc1 (10 mg/kg) and DNL (80 mg/kg) were administered intraperitoneally for 4 weeks and orally for 14 days, respectively, before I/R injury. Infarct size was measured through triphenyl-tetrazolium-chloride staining. ELISA assay was conducted to quantify the levels of cardiotroponin, and myocardial content of TNF-α and glutathione. Western blotting was employed to detect the expression of TLR4/MyD88/NF-κB proteins. GMc1 and DNL significantly reduced the infarct size to a similar extent ( p < 0.05) but their combined effect was greater than individual ones ( p < 0.01). Combination therapy significantly restored the left ventricular end-diastolic and developed pressures at the end of reperfusion as compared with the untreated group ( p < 0.01). Although the GMc1 and DNL reduced the levels of inflammatory cytokine TNF-α and increased the contents of antioxidant glutathione significantly, their individual effects on the reduction of protein expression of TLR4/MyD88/NF-κB pathway were not consistent. However, their combination could significantly reduce all parameters of this inflammatory pathway as compared to untreated I/R rats ( p < 0.001). Therefore, the combined treatment with GMc1 and DNL increased the potency of each intervention in protecting the aged hearts against I/R injury. Reduction in the activity of the TLR4/MyD88/NF-κB signaling pathway and subsequent modulation of the activity of inflammatory cytokines and endogenous antioxidants play an important role in this cardioprotection.

Implication of anti-angiogenic VEGF-A165b in angiogenesis and systolic function after reperfused myocardial infarction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
V Marcos Garces ◽  
C Rios-Navarro ◽  
L Hueso ◽  
A Diaz ◽  
C Bonanad ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Adjuvant Therapy ◽  
Ejection Fraction ◽  
Infarct Size ◽  
Systolic Function ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Funding Source ◽  
Coronary Reperfusion ◽  
Ventricular Ejection Fraction

Abstract Background Angiogenesis participates in re-establishing microcirculation after myocardial infarction (MI). Purpose In this study, we aim to further understand the role of the anti-angiogenic isoform vascular endothelial growth factor (VEGF)-A165b after MI and explore its potential as a co-adjuvant therapy to coronary reperfusion. Methods Two mice MI models were formed: 1) permanent coronary ligation (non-reperfused MI), 2) transient 45-min coronary occlusion followed by reperfusion (reperfused MI); in both models, animals underwent echocardiography before euthanasia at day 21 after MI induction. Serum and myocardial VEGF-A165b levels were determined. In both experimental MI models, functional and structural implication of VEGF-A165b blockade was assessed. In a cohort of 104 ST-segment elevation MI patients, circulating VEGF-A165b levels were correlated with cardiovascular magnetic resonance-derived left ventricular ejection fraction at 6-months and with the occurrence of adverse events (death, heart failure and/or re-infarction). Results In both models, circulating and myocardial VEGF-A165b presence was increased 21 days after MI induction. Serum VEGF-A165b levels inversely correlated with systolic function evaluated by echocardiography. VEGF-A165b blockage increased capillary density, reduced infarct size, and enhanced left ventricular function in reperfused, but not in non-reperfused MI experiments. In patients, higher VEGF-A165b levels correlated with depressed ejection fraction and worse outcomes. Conclusions In experimental and clinical studies, higher serum VEGF-A165b levels associates with a worse systolic function. Its blockage enhances neoangiogenesis, reduces infarct size, and increases ejection fraction in reperfused, but not in non-reperfused MI experiments. Therefore, VEGF-A165b neutralization represents a potential co-adjuvant therapy to coronary reperfusion. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was funded by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (Exp. PIE15/00013, PI17/01836, PI18/00209 and CIBERCV16/11/00486).

Cardioprotection with esmolol-based cardioplegia for non-infarcted and infarcted rat hearts

2021 ◽  
Author(s):  
Alexander B Veitinger ◽  
Audrey Komguem ◽  
Lena Assling-Simon ◽  
Martina Heep ◽  
Julia Schipke ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
Infarct Size ◽  
Myocardial Infarct ◽  
Lactate Production ◽  
Left Ventricular ◽  
Myocardial Infarct Size ◽  
Cardioplegic Arrest ◽  
Blood Cardioplegia ◽  
Rat Hearts

Abstract OBJECTIVES Esmolol-based cardioplegic arrest offers better cardioprotection than crystalloid cardioplegia but has been compared experimentally with blood cardioplegia only once. We investigated the influence of esmolol crystalloid cardioplegia (ECCP), esmolol blood cardioplegia (EBCP) and Calafiore blood cardioplegia (Cala) on cardiac function, metabolism and infarct size in non-infarcted and infarcted isolated rat hearts. METHODS Two studies were performed: (i) the hearts were subjected to a 90-min cardioplegic arrest with ECCP, EBCP or Cala and (ii) a regional myocardial infarction was created 30 min before a 90-min cardioplegic arrest. Left ventricular peak developed pressure (LVpdP), velocity of contractility (dLVP/dtmax), velocity of relaxation over time (dLVP/dtmin), heart rate and coronary flow were recorded. In addition, the metabolic parameters were analysed. The infarct size was determined by planimetry, and the myocardial damage was determined by electron microscopy. RESULTS In non-infarcted hearts, cardiac function was better preserved with ECCP than with EBCP or Cala relative to baseline values (LVpdP: 100 ± 28% vs 86 ± 11% vs 57 ± 7%; P = 0.002). Infarcted hearts showed similar haemodynamic recovery for ECCP, EBCP and Cala (LVpdP: 85 ± 46% vs 89 ± 55% vs 56 ± 26%; P = 0.30). The lactate production with EBCP was lower than with ECCP (0.6 ± 0.7 vs 1.4 ± 0.5 μmol/min; P = 0.017). The myocardial infarct size and (ECCP vs EBCP vs Cala: 16 ± 7% vs 15 ± 9% vs 24 ± 13%; P = 0.21) the ultrastructural preservation was similar in all groups. CONCLUSIONS In non-infarcted rat hearts, esmolol-based cardioplegia, particularly ECCP, offers better myocardial protection than Calafiore. After an acute myocardial infarction, cardioprotection with esmolol-based cardioplegia is similar to that with Calafiore.

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