Abstract 12547: Time-Course Influence of Brain Death on Cardiac Function and Its Impact on Posttransplant Graft Function

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Shiliang Li ◽  
Sevil Korkmaz ◽  
Sivakkanan Loganathan ◽  
Tamás Radovits ◽  
Peter Hegedüs ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Brain Death ◽  
Time Course ◽  
Ischemia Reperfusion ◽  
Balloon Catheter ◽  
Graft Function ◽  
Left Ventricular ◽  
Control Group ◽  
Sham Operation ◽  
Brain Dead

Introduction: Heart transplantation became the most effective treatment for end-stage heart failure. Donors after brain death are currently the only reliable source for cardiac transplants. However, hemodynamic instability and cardiac dysfunction have been demonstrated in brain-dead donors and this could therefore also affect posttransplant graft function. Hypothesis: Our aims were to evaluate in rats the time-course cardiac influence of brain death and we tested the hypothesis that brain death impairs graft left ventricular function. Methods: Lewis rats were either maintained brain death for 5h by inflation of a subdurally placed balloon catheter (n=7) or subjected to sham-operation (control group, n=9). We continuously assessed cardiac function during 5 h. Then, hearts were excised, stored in cold preservation solution for 1 h, and heterotopically transplanted. We evaluated graft function 1.5 h after transplantation. Results: Brain death was associated with decreased left ventricular contractility (ejection fraction: 37±6% vs. 57±5%; dP/dt max : 4770±197 mmHg/s vs. 7604 ±348 mmHg/s; dP/dt max -EDV: 60±7 mmHg/s vs. 74±2 mmHg/s; E max : 2.4±0.1 mmHg/μl vs. 4.4±0.3 mmHg/μl; PRSW: 47±9 mmHg vs. 78±3 mmHg; p<0.05) and relaxation (dP/dt min: -6638±722 mmHg/s vs. -11285±539 mmHg/s; Tau: 12.6±0.7 ms vs.10.5±0.4 ms; EDPVR: 0.33±0.14 mmHg/μl vs. 0.09±0.03 mmHg/μl, p<0.05) 45 min after its initiation and for the rest of 5 h compared to controls. Moreover, after transplantation, graft systolic and diastolic functions were impaired in the brain-dead group compared to controls (reflected by decreased left ventricular systolic and developed pressures, dP/dt max and dP/dt min , and prolonged Tau). Conclusions: In conclusion, we have a well detailed characterized in vivo rat model to examine the influence of brain death on ventricular dysfunction using a microconductance catheter technology via pressure-volume analysis. These results demonstrate that brain death increases the susceptibility of donor heart to ischemia/reperfusion injury after transplantation.

Abstract 12544: Dimethyloxalylglycine Treatment of Brain-Dead Donor Rats Improves Both Donor and Graft Left-Ventricular Function After Heart Transplantation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Peter Hegedüs ◽  
Shiliang Li ◽  
Sevil Korkmaz ◽  
Tamás Radovits ◽  
Samer Alsaid ◽  
...  
Keyword(s):  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Balloon Catheter ◽  
Graft Function ◽  
Physiological Saline ◽  
Left Ventricular ◽  
Lv Function ◽  
Inflated Balloon ◽  
Brain Dead

Introduction: Cardiac transplantation is the most effective treatment of end-stage heart failure. Brain dead (BD) donors are currently the only reliable source for cardiac grafts. However, hemodynamic instability and cardiac dysfunction have been demonstrated in BD donors and this could therefore also affect posttransplant graft function. Hypothesis: Based upon the protective effect of Prolyl-Hydroxylase (PHD)-Hypoxia Inducible Factor (HIF)-1 pathway against ischemia/reperfusion injury (IRI), we tested the hypothesis that treatment of BD donor rats with the PHD inhibitor dimethyloxalylglycine (DMOG) results in a better graft heart condition in recipients after heterotopic transplantation. Methods: Lewis rats were injected with one shot DMOG (30 mg/kg i.v.) (n=7) or equal volume of physiological saline (n=7) and maintained BD for 5h by a subdurally placed and inflated balloon catheter. Controls were sham-operated (n=11). Then, hearts were explanted, stored in cold preservation solution, heterotopically transplanted and after 1.5h reperfusion left-ventricular (LV) graft function was evaluated in vivo . Myocardial histological and molecular biological analyses were performed. Results: BD was associated with decreased LV function. DMOG treatment of BD animals resulted in better load-independent contractility and end-diastolic stiffness parameters (ESPVR E' max (mmHg/μl): BD+DMOG: 3.7±0.6 vs BD: 3.1±0.5; EDPVR (mmHg/μl): BD+DMOG: 0.13±0.03 vs BD: 0.31±0.06 p<0.05). Following transplantation, DMOG treatment of BD donors significantly improved altered LV systolic and diastolic function (at 80μL volume dP/dt max (mmHg/s): BD+DMOG: 2284±213 vs BD: 1854±124 p<0.05; dP/dt min (mmHg/s): BD+DMOG: 1586±183 vs BD: 1154±74, p<0.05; Tau-W (ms): BD+DMOG: 33±4 vs BD: 43±9 p<0.05). Significantly lower myocardial inflammatory cell infiltration, necrosis, and DNA-strand breakage were evident in DMOG treated BD group compared to BD group. Conclusions: Pre-treatment of BD heart donors with DMOG resulted in a significantly better LV graft function after transplantation. These results support the view that preconditioning of BD donors through the activation of HIF-1 pathway has a protective role against myocardial IRI after transplantation.

Cardiac function in hearts isolated from a rat model deficient in mast cells

2005 ◽  
Vol 288 (2) ◽  
pp. H632-H637 ◽  
Author(s):  
Richard H. Kennedy ◽  
Martin Hauer-Jensen ◽  
Jacob Joseph
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Cardiac Function ◽  
Systolic Function ◽  
Ischemia Reperfusion ◽  
Balloon Catheter ◽  
Weight Ratio ◽  
Left Ventricular ◽  
Heart Weight ◽  
Adult Rats

Several studies have examined the role of mast cells in the myocardial response to injury such as that caused by hypertension and ischemia-reperfusion. However, little is known about the influence of mast cells on normal myocardial structure and function. The present experiments examined cardiac function in Langendorff-perfused hearts isolated from 6- and 9-mo-old male mast cell-deficient ( Ws/ Ws) and mast cell-competent rats. A fluid-filled balloon catheter was used to measure left ventricular diastolic and systolic function at increasing preload volumes. At 6 mo of age, mast cell-deficient rats showed a slight cardiac hypertrophy (as monitored by heart weight and heart weight-to-body weight ratio) but no significant change in maximum observed systolic or diastolic function. In contrast, at 9 mo of age, the mast cell-deficient group showed no signs of hypertrophy but displayed a diastolic dysfunction characterized by decreased compliance without a significant decline in maximum observed basal −dP/d tmax. There were no significant differences in maximum observed values for measures of systolic function (developed pressure and +dP/d tmax). In summary, the results of this study in adult rats suggest that mast cells influence cardiac function in the absence of injury and that observed differences between mast cell-competent and -deficient animals vary with age. Thus it is important to consider these “physiological” actions and resulting changes in function when studying effects of insult in mast cell-deficient models.

scholarly journals Effects of propofol on cardiac function and miR-494 expression in rats with hepatic ischemia/reperfusion injury

2021 ◽  
Vol 49 (3) ◽  
pp. 030006052199098
Author(s):  
Jie Lv ◽  
Xiaohua Zou ◽  
Chao Yu ◽  
Wei Ou ◽  
Chengyi Sun
Keyword(s):  
Cardiac Function ◽  
Group Treatment ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Sham Operation ◽  
Myocardial Cells ◽  
Hepatic Ischemia ◽  
Sham Operation Group ◽  
Hepatic Ischemia Reperfusion

Objective This study aimed to investigate the effects of propofol on cardiac function and miR-494 expression in rats with hepatic ischemia/reperfusion (I/R) injury. Methods Forty healthy adult male Sprague-Dawley rats were allocated to the sham operation group and three hepatic I/R injury groups. The I/R injury groups included I/R injury only (I/R group), treatment with propofol (propofol group), and treatment with propofol + overexpressed miR-494 (propofol+miR-494 group). Apoptosis of myocardial cells and changes in cardiac function indices, including left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left ventricular posterior wall thickness, as well as changes in miR-494, were monitored. Results The apoptotic rate of myocardial cells in the I/R group was higher, cardiac function was deteriorated, and miR-494 levels were elevated compared with the sham group. The apoptotic rate was lower, cardiac function was improved, and miR-494 levels were suppressed in the propofol group compared with the I/R group. The apoptotic rate was higher, cardiac function was deteriorated, and miR-494 levels were elevated in the propofol+miR-494 group compared with the propofol group. Conclusion Propofol plays a vital role in preventing myocardial cell apoptosis and improvement of cardiac function by suppressing miR-494 in a hepatic I/R injury rat model.

scholarly journals A Randomized Controlled Trial to Study the Effect of Yoga Therapy on Cardiac Function and N Terminal Pro BNP in Heart Failure

2014 ◽  
Vol 9 ◽  
pp. IMI.S13939 ◽  
Author(s):  
Bandi Hari Krishna ◽  
Pravati Pal ◽  
G. K. Pal ◽  
J. Balachander ◽  
E. Jayasettiaseelon ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Function ◽  
Medical Therapy ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Control Group ◽  
Tei Index ◽  
Ventricular Ejection Fraction ◽  
Yoga Therapy ◽  
Standard Medical Therapy

Aims The purpose of this study was to evaluate whether yoga training in addition to standard medical therapy can improve cardiac function and reduce N terminal pro B-type natriuretic peptide (NT pro BNP) in heart failure (HF). Methods 130 patients were recruited and randomized into two groups: Control Group (CG) ( n = 65), Yoga Group (YG). In YG, 44 patients and in CG, 48 patients completed the study. Cardiac function using left ventricular ejection fraction (LVEF), myocardial performance index (Tei index), and NT pro BNP, a biomarker of HF, was assessed at baseline and after 12 weeks. Result Improvement in LVEF, Tei index, and NT pro BNP were statistically significant in both the groups. Furthermore, when the changes in before and after 12 weeks were in percentage, LVEF increased 36.88% in the YG and 16.9% in the CG, Tei index was reduced 27.87% in the YG and 2.79% in the CG, NT pro BNP was reduced 63.75% in the YG and 10.77% in the CG. The between group comparisons from pre to post 12 weeks were significant for YG improvements (LVEF, P < 0.01, Tei index, P < 0.01, NT pro BNP, P < 0.01). Conclusion These results indicate that the addition of yoga therapy to standard medical therapy for HF patients has a markedly better effect on cardiac function and reduced myocardial stress measured using NT pro BNP in patients with stable HF.

Breathing nitric oxide plus hydrogen gas reduces ischemia-reperfusion injury and nitrotyrosine production in murine heart

2013 ◽  
Vol 305 (4) ◽  
pp. H542-H550 ◽  
Author(s):  
Toshihiro Shinbo ◽  
Kenichi Kokubo ◽  
Yuri Sato ◽  
Shintaro Hagiri ◽  
Ryuji Hataishi ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cardiac Function ◽  
Infarct Size ◽  
Ischemia Reperfusion Injury ◽  
Myocardial Dysfunction ◽  
Ischemia Reperfusion ◽  
Neutrophil Infiltration ◽  
Left Ventricular ◽  
Hydrogen Gas ◽  
Coronary Artery Ligation

Inhaled nitric oxide (NO) has been reported to decrease the infarct size in cardiac ischemia-reperfusion (I/R) injury. However, reactive nitrogen species (RNS) produced by NO cause myocardial dysfunction and injury. Because H2 is reported to eliminate peroxynitrite, it was expected to reduce the adverse effects of NO. In mice, left anterior descending coronary artery ligation for 60 min followed by reperfusion was performed with inhaled NO [80 parts per million (ppm)], H2 (2%), or NO + H2, starting 5 min before reperfusion for 35 min. After 24 h, left ventricular function, infarct size, and area at risk (AAR) were assessed. Oxidative stress associated with reactive oxygen species (ROS) was evaluated by staining for 8-hydroxy-2′-deoxyguanosine and 4-hydroxy-2-nonenal, that associated with RNS by staining for nitrotyrosine, and neutrophil infiltration by staining for granulocyte receptor-1. The infarct size/AAR decreased with breathing NO or H2 alone. NO inhalation plus H2 reduced the infarct size/AAR, with significant interaction between the two, reducing ROS and neutrophil infiltration, and improved the cardiac function to normal levels. Although nitrotyrosine staining was prominent after NO inhalation alone, it was eliminated after breathing a mixture of H2 with NO. Preconditioning with NO significantly reduced the infarct size/AAR, but not preconditioning with H2. In conclusion, breathing NO + H2 during I/R reduced the infarct size and maintained cardiac function, and reduced the generation of myocardial nitrotyrosine associated with NO inhalation. Administration of NO + H2 gases for inhalation may be useful for planned coronary interventions or for the treatment of I/R injury.

scholarly journals Brain Death-Induced Inflammatory Activity is Similar to Sepsis-Induced Cytokine Release

2018 ◽  
Vol 27 (10) ◽  
pp. 1417-1424 ◽  
Author(s):  
Patrícia Schwarz ◽  
Geisiane Custódio ◽  
Jakeline Rheinheimer ◽  
Daisy Crispim ◽  
Cristiane B. Leitão ◽  
...  
Keyword(s):  
Brain Death ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Release Kinetics ◽  
Magnetic Bead ◽  
Control Group ◽  
Cytokine Release ◽  
Plasma Cytokine ◽  
Ifn Γ ◽  
Brain Dead

Brain death (BD) is associated with a systemic inflammation leading to worse graft outcomes. This study aimed to compare plasma cytokine values between brain-dead and critically ill patients, including septic and non-septic controls, and evaluate cytokine release kinetics in BD. Sixteen brain-dead and 32 control patients (16 with and 16 without sepsis) were included. Plasma cytokines were measured by magnetic bead assay after the first clinical exam consistent with BD and every 6 hours thereafter, and at the time of study entry in the control group. The values for IL-8 and IFN-γ were higher in brain-dead and septic patients than in non-septic patients [IL-8: 80.3 (18.7–169.6) vs. 68.2 (22.4–359.4) vs. 16.4 (9.2–42.7) pg/mL; P = 0.006; IFN-γ: 2.8 (1.6-6.1) vs. 3.4 (1.2–9.0) vs. 0.5 (0.5–1.8) pg/mL; P = 0.012]. TNF showed a clear tendency to increase in brain-dead patients [2.7 (1.0–4.8) vs. 1.0 (1.0–5.6) vs. 1.0 (1.0–1.0) pg/mL; P = 0.051], and IL-6 values were higher in brain-dead patients than in non-septic controls [174.5 (104.9–692.5) vs. 13.2 (7.3–38.6) pg/mL; P = 0.002]. These differences remained even after excluding brain-dead patients who also had sepsis ( n = 3). IL-1β and IL-10 values increased from baseline to time point 2 (∼6 hours later) [IL-1β: 5.39 (1.93–16.89) vs. 7.11 (1.93–29.13) pg/mL; P = 0.012; IL-10: 8.78 (3.62–16.49) vs. 15.73 (5.49–23.98) pg/mL; P = 0.009]. BD-induced and sepsis-induced plasma cytokine values were similarly high, and both were higher than the observed in non-septic critically ill patients.

Short-term exercise training can improve myocardial tolerance to I/R without elevation in heat shock proteins

2001 ◽  
Vol 281 (3) ◽  
pp. H1346-H1352 ◽  
Author(s):  
Karyn L. Hamilton ◽  
Scott K. Powers ◽  
Takao Sugiura ◽  
Sunjoo Kim ◽  
Shannon Lennon ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Antioxidant Defenses ◽  
Control Group ◽  
Shock Proteins ◽  
Mnsod Activity ◽  
Over Time

We examined the effects of 3 days of exercise in a cold environment on the expression of left ventricular (LV) heat shock proteins (HSPs) and contractile performance during in vivo ischemia-reperfusion (I/R). Sprague-Dawley rats were divided into the following three groups ( n = 12/group): 1) control, 2) exercise (60 min/day) at 4°C (E-Cold), and 3) exercise (60 min/day) at 25°C (E-Warm). Left anterior descending coronary occlusion was maintained for 20 min, followed by 30 min of reperfusion. Compared with the control group, both the E-Cold and E-Warm groups maintained higher ( P < 0.05) LV developed pressure, first derivative of pressure development over time (+dP/d t), and pressure relaxation over time (−dP/d t) throughout I/R. Relative levels of HSP90, HSP72, and HSP40 were higher ( P < 0.05) in E-Warm animals compared with both control and E-Cold. HSP10, HSP60, and HSP73 did not differ between groups. Exercise increased manganese superoxide dismutase (MnSOD) activity in both E-Warm and E-Cold hearts ( P < 0.05). Protection against I/R-induced lipid peroxidation in the LV paralleled the increase in MnSOD activity whereas lower levels of lipid peroxidation were observed in both E-Warm and E-Cold groups compared with control. We conclude that exercise-induced myocardial protection against a moderate duration I/R insult is not dependent on increases in myocardial HSPs. We postulate that exercise-associated cardioprotection may depend, in part, on increases in myocardial antioxidant defenses.

scholarly journals Effects of human recombinant growth hormone on exercise capacity, cardiac structure, and cardiac function in patients with adult-onset growth hormone deficiency

2017 ◽  
Vol 45 (6) ◽  
pp. 1708-1719 ◽  
Author(s):  
S Gonzalez ◽  
JD Windram ◽  
T Sathyapalan ◽  
Z Javed ◽  
AL Clark ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Cardiac Function ◽  
Growth Hormone Deficiency ◽  
Exercise Capacity ◽  
Left Ventricular ◽  
Hormone Deficiency ◽  
Control Group ◽  
Cardiac Structure ◽  
Adult Onset ◽  
Risk Of Death

Objective Epidemiological studies suggest that adult-onset growth hormone deficiency (AGHD) might increase the risk of death from cardiovascular causes. Methods This was a 6-month double-blind, placebo-controlled, randomised, cross-over trial followed by a 6-month open-label phase. Seventeen patients with AGHD received either recombinant human growth hormone (rGH) (0.4 mg injection daily) or placebo for 12 weeks, underwent washout for 2 weeks, and were then crossed over to the alternative treatment for a further 12 weeks. Cardiac magnetic resonance imaging, echocardiography, and cardiopulmonary exercise testing were performed at baseline, 12 weeks, 26 weeks, and the end of the open phase (12 months). The results were compared with those of 16 age- and sex-matched control subjects. Results At baseline, patients with AGHD had a significantly higher systolic blood pressure, ejection fraction, and left ventricular mass than the control group, even when corrected for body surface area. Treatment with rGH normalised the insulin-like growth factor 1 concentration without an effect on exercise capacity, cardiac structure, or cardiac function. Conclusion Administration of rGH therapy for 6 to 9 months failed to normalise the functional and structural cardiac differences observed in patients with AGHD when compared with a control group.

The Effect of Gypenosides on Cardiac Function and Expression of Cytoskeletal Genes of Myocardium in Diabetic Cardiomyopathy Rats

2009 ◽  
Vol 37 (06) ◽  
pp. 1059-1068 ◽  
Author(s):  
Min Ge ◽  
Shanfeng Ma ◽  
Liang Tao ◽  
Sudong Guan
Keyword(s):  
Cardiac Function ◽  
Diabetic Cardiomyopathy ◽  
Diastolic Pressure ◽  
Pure Water ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Control Group ◽  
Sprague Dawley ◽  
Gene Expressions ◽  
Ventricular Systolic Pressure

The relationship between changes of cardiac function and the gene expressions of two major myocardial skeleton proteins, titin and nebulin, and the effect of gypenosides on these gene expressions in diabetic cardiomyopathy rat were explored in the present study. Forty Sprague-Dawley rats were randomly divided into three groups: control group, diabetic cardiomyopathy group and gypenosides-treated diabetic cardiomyopathy group. The diabetic cardiomyopathy was induced in rats by injecting streptozotocin (STZ, 55 mg/kg) intraperitoneally. Seven weeks after the rats suffered from diabetes, the rats were treated with gypenosides 100 mg/kg per day orally for six weeks in gypenosides-treated group. In the meanwhile, the pure water was given to diabetic cardiomyopathy and the control groups. Subsequently, the cardiac functions, including left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), ± dP/dtmax and t–dP/dmaxt, as well as the mRNA content and proteins of titin and nebulin in myocardium were determined. The results indicated that (1) the diabetic cardiomyopathy rats had decreased LVSP and ± dP/dtmax, increased LVEDP, and prolonged t–dP/dtmax than normal rats; (2) LVSP and ± dP/dtmax in diabetic cardiomyopathy rats treated with gypenosides were significantly higher and LVEDP and t–dP/dtmax were significantly lower than those without giving gypenosides; (3) the mRNA contents and proteins of titin and nebulin in diabetic cardiomyopathy rats were remarkably lower than those in the control rats and gypenosides had no effect on mRNA and protein expression levels of titin and nebulin in diabetic cardiomyopathy rats. We conclude that (1) the cardiac function as well as the mRNA expressions of titin and nebulin decreased in diabetic cardiomyopathy rats; (2) gypenosides secure cardiac muscles and their function from diabetic impairment and these beneficial effects of gypenosides are not by changing the expressions of titin and nebulin.

scholarly journals Antihypertrophic Memory after Regression of Exercise-induced Physiological Myocardial Hypertrophy is Mediated by the Long Noncoding RNA Mhrt779

Circulation ◽  
2021 ◽  
Author(s):  
Hairuo Lin ◽  
Yingqi Zhu ◽  
Cankun Zheng ◽  
Donghong Hu ◽  
Siyuan Ma ◽  
...  
Keyword(s):  
Western Blot ◽  
Noncoding Rna ◽  
Rna Binding ◽  
Myocardial Hypertrophy ◽  
Quantitative Polymerase Chain Reaction ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Control Group ◽  
Sham Operation ◽  
Ventricular Ejection Fraction

Background: Exercise can induce physiological myocardial hypertrophy (PMH), and former athletes can live 5-6 years longer than nonathletic controls, suggesting a benefit after regression of PMH. We previously reported that regression of pathological myocardial hypertrophy has antihypertrophic effects. Accordingly, we hypothesized that antihypertrophic memory exists even after PMH has regressed, increasing myocardial resistance to subsequent pathological hypertrophic stress. Methods: C57BL/6 mice were submitted to 21 days of swimming training to develop PMH. After termination of exercise, PMH regressed within 1 week. PMH regression mice (exercise hypertrophic preconditioning group, EHP) and sedentary mice (control group) then underwent transverse aortic constriction (TAC) or a sham operation for 4 weeks. Cardiac remodeling and function were evaluated using echocardiography, invasive left ventricular hemodynamic measurement and histological analysis. LncRNA sequencing, chromatin immunoprecipitation assay (ChIP), and comprehensive identification of RNA-binding proteins by mass spectrometry (CHIRP-MS) and Western blot were used to investigate the role of Mhrt779 involved in the anti-hypertrophy effect induced by EHP. Results: At 1 and 4 weeks after TAC, the EHP group showed less increase in myocardial hypertrophy and lower expression of the Nppa and Myh7 genes than the sedentary group. At 4 weeks after TAC, EHP mice had less pulmonary congestion, smaller left ventricular dimensions and end-diastolic pressure, and a larger left ventricular ejection fraction and maximum pressure change rate than sedentary mice. Quantitative polymerase chain reaction (qPCR) revealed that the long noncoding myosin heavy chain associated RNA transcript Mhrt779 was one of the markedly upregulated long noncoding RNAs in the EHP group. Silencing of Mhrt779 attenuated the antihypertrophic effect of EHP in mice with TAC and in cultured cardiomyocytes treated with angiotensin II, and overexpression enhanced the antihypertrophic effect. By ChIP and qPCR, we found that EHP increased histone 3 trimethylation (H3K4me3 and H3K36me3) at the a4 promoter of Mhrt779 . CHIRP-MS and Western blot showed that Mhrt779 can bind Brg1 to inhibit the activation of Hdac2/Akt/GSK3β pathway induced by pressure overload. Conclusions: Myocardial hypertrophy preconditioning evoked by exercise increases resistance to pathological stress via an antihypertrophic effect mediated by a signal pathway of Mhrt779 /Brg1/Hdac2/p-Akt/p-GSK3β.

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