Prediction of Poststorage Cardiac Function From Cardioplegic Effluent in an Ex Vivo Porcine Heart Model

2019 ◽  
Vol 2 (4) ◽  
Author(s):  
Benjamin Kappler ◽  
Sjoerd van Tuijl ◽  
Teus J. van Laar ◽  
Dara R. Pabittei ◽  
Marc P. Buijsrogge ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Cardiac Function ◽  
Cardiac Dysfunction ◽  
Ex Vivo ◽  
Heart Function ◽  
Laboratory Animals ◽  
Organ Protection ◽  
Isolated Hearts ◽  
Cardiac Functions ◽  
Proactive Measures

Abstract The use of slaughterhouse-based hearts has advantages over hearts obtained from laboratory animals for preclinical testing. However, slaughterhouse hearts have greater variability in cardiac function; this has resulted in a dispute over their actual reproducibility. This study explores the feasibility of examining the cardioplegic effluent during hypothermic cardiac arrest for the presence of biomarkers to predict poststorage heart function of slaughterhouse hearts. This may enable proactive measures to optimize preservation strategies and improve the initial cardiac performance of slaughterhouse heart experiments. Slaughterhouse pig hearts (n = 9; 420 ± 30 g) were arrested and flushed with an additional liter cardioplegia after 1 h. Effluent samples were examined for ammonia, lactate, troponin, and inorganic phosphate. After 2 h, hearts were hemoreperfused in the ex vivo heart platform PhysioHeart™ to restore physiological cardiac functions and to identify correlations between biomarkers and cardiac output. There was a negative correlation between cardiac output of revived hearts and levels of ammonia (r = −0.865; p = 0.002) and lactate (r = −0.763; p = 0.01). No correlation was found between cardiac output and levels of phosphate (r = −0.553; p = 0.12) and troponin (r = −0.367; p = 0.331). The analysis approach to assess cardioplegic biomarkers was feasible and enabled the estimation of the effectiveness of organ protection and cardiac function before reperfusion. Ammonia is a predictor for cardiac dysfunction. Effluent analysis prior to heart revival can uncover poststorage cardiac dysfunction in isolated hearts and may prevent failed experiments while improving reproducibility and standardization.

Attenuated cardiac function degradation in ex vivo pig hearts

2019 ◽  
Vol 43 (3) ◽  
pp. 173-179
Author(s):  
Benjamin Kappler ◽  
Sjoerd van Tuijl ◽  
Bülent Ergin ◽  
Louis Fixsen ◽  
Marco Stijnen ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Ex Vivo ◽  
Heart Function ◽  
Blood Parameters ◽  
Diagnostic Tools ◽  
Control Group ◽  
Isolated Hearts ◽  
Cardiac Hemodynamics ◽  
Cardiac Pump Function

Isolated hearts offer the opportunity to evaluate heart function, treatments, and diagnostic tools without in vivo factor interference. However, the early loss of cardiac function and edema occur over time and do limit the duration of the experiment. This research focuses on delaying these limitations using optimal blood control. This study examines whether blood conditioning by means of the combination of blood predilution and hemodialysis can significantly reduce cardiac function degradation. Slaughterhouse porcine hearts were revived in the PhysioHeart™ platform to restore physiological cardiac performance. Twelve hearts were divided into a control group and a dialysis group; in the latter group, hemodialysis was attached to the blood reservoir. Cardiac hemodynamics and blood parameters were recorded and evaluated. Blood conditioning significantly reduced the loss of cardiac pump function (control group vs dialysis group, −14.9 ± 6.3%/h vs −9.7 ± 2.7%/h) and loss of cardiac output (control group vs dialysis group, −11.8 ± 3.4%/h vs −5.9 ± 2.0%/h). Hemodialysis resulted in physiological and stable blood parameters, whereas in the control group ions reached pathological values, while interstitial edema still occurred. The combination of blood predilution and hemodialysis significantly attenuated ex vivo cardiac function degradation and delayed the loss of cardiac hemodynamics. We hypothesized that besides electrolyte and metabolic control, the hemodialysis-accompanied increase in hematocrit resulted in improved oxygen transport. This could have temporarily compensated the deleterious effect of an increased oxygen-diffusion distance due to edema in the dialysis group and resulted in less progression of cell decay. Clinically validated measures delaying edema might improve the effectiveness of the PhysioHeart™ platform.

Targeted inactivation of Gαi does not alter cardiac function or β-adrenergic sensitivity

2001 ◽  
Vol 280 (2) ◽  
pp. H569-H575 ◽  
Author(s):  
Mohit Jain ◽  
Chee Chew Lim ◽  
Kohzo Nagata ◽  
Vannessa M. Davis ◽  
David S. Milstone ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Ventricular Myocytes ◽  
Ex Vivo ◽  
Cardiac Response ◽  
Similar Degree ◽  
Wild Type ◽  
Isolated Hearts ◽  
Targeted Inactivation ◽  
Contractile Performance

Inhibitory Gαi protein increases in the myocardium during hypertrophy and has been associated with β-adrenergic receptor (β-AR) desensitization, contractile dysfunction, and progression of cardiac disease. The role of Gαi proteins in mediating basal cardiac function and β-AR response in nonpathological myocardium, however, is uncertain. Transgenic mice with targeted inactivation of Gαi2 or Gαi3 were examined for in vivo cardiac function with the use of conscious echocardiography and for ex vivo cardiac response to inotropic stimulation with the use of Langendorff blood-perfused isolated hearts and adult ventricular cardiomyocytes. Echocardiography revealed that percent fractional shortening and heart rate were similar among wild-type, Gαi2 -null, and Gαi3 -null mice. Comparable baseline diastolic and contractile performance was also observed in isolated hearts and isolated ventricular myocytes from wild-type mice and mice lacking Gαi proteins. Isoproterenol infusion enhanced diastolic and contractile performance to a similar degree in wild-type, Gαi2 -null, and Gαi3 -null mice. These data demonstrate no observable role for inhibitory G proteins in mediating basal cardiac function or sensitivity to β-AR stimulation in nonpathological myocardium.

Profiling substrate fluxes in the isolated working mouse heart using 13C-labeled substrates: focusing on the origin and fate of pyruvate and citrate carbons

2004 ◽  
Vol 286 (4) ◽  
pp. H1461-H1470 ◽  
Author(s):  
Maya Khairallah ◽  
François Labarthe ◽  
Bertrand Bouchard ◽  
Gawiyou Danialou ◽  
Basil J. Petrof ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Ex Vivo ◽  
Heart Function ◽  
Acid Oxidation ◽  
Mouse Heart ◽  
Relative Contribution ◽  
Cardiac Functions ◽  
Lactate And Pyruvate

The availability of genetically modified mice requires the development of methods to assess heart function and metabolism in the intact beating organ. With the use of radioactive substrates and ex vivo perfusion of the mouse heart in the working mode, previous studies have documented glucose and fatty acid oxidation pathways. This study was aimed at characterizing the metabolism of other potentially important exogenous carbohydrate sources, namely, lactate and pyruvate. This was achieved by using 13C-labeling methods. The mouse heart perfusion setup and buffer composition were optimized to reproduce conditions close to the in vivo milieu in terms of workload, cardiac functions, and substrate-hormone supply to the heart (11 mM glucose, 0.8 nM insulin, 50 μM carnitine, 1.5 mM lactate, 0.2 mM pyruvate, 5 nM epinephrine, 0.7 mM oleate, and 3% albumin). The use of three differentially 13C-labeled carbohydrates and a 13C-labeled long-chain fatty acid allowed the quantitative assessment of the metabolic origin and fate of tissue pyruvate as well as the relative contribution of substrates feeding acetyl-CoA (pyruvate and fatty acids) and oxaloacetate (pyruvate) for mitochondrial citrate synthesis. Beyond concurring with the notion that the mouse heart preferentially uses fatty acids for energy production (63.5 ± 3.9%) and regulates its fuel selection according to the Randle cycle, our study reports for the first time in the mouse heart the following findings. First, exogenous lactate is the major carbohydrate contributing to pyruvate formation (42.0 ± 2.3%). Second, lactate and pyruvate are constantly being taken up and released by the heart, supporting the concept of compartmentation of lactate and glucose metabolism. Finally, mitochondrial anaplerotic pyruvate carboxylation and citrate efflux represent 4.9 ± 1.8 and 0.8 ± 0.1%, respectively, of the citric acid cycle flux and are modulated by substrate supply. The described 13C-labeling strategy combined with an experimental setup that enables continuous monitoring of physiological parameters offers a unique model to clarify the link between metabolic alterations, cardiac dysfunction, and disease development.

Predicting donor heart function in a heartbeat

2020 ◽  
Vol 12 (538) ◽  
pp. eabb5667
Author(s):  
Steven P. Keller
Keyword(s):  
Machine Learning ◽  
Cardiac Function ◽  
Ex Vivo ◽  
Heart Function ◽  
Donor Heart ◽  
Learning Methods ◽  
Ex Vivo Perfusion ◽  
Machine Learning Methods

Machine learning methods can assess contractility of donor hearts maintained via ex vivo perfusion to predict posttransplant cardiac function.

scholarly journals Oroxylin A, but Not Vasopressin, Ameliorates Cardiac Dysfunction of Endotoxemic Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Chin-Hung Liu ◽  
Mei-Fang Chen ◽  
Tzu-Ling Tseng ◽  
Lih-Geeng Chen ◽  
Jon-Son Kuo ◽  
...  
Keyword(s):  
Cardiac Dysfunction ◽  
Constant Pressure ◽  
Myocardial Dysfunction ◽  
Flow Mode ◽  
Constant Flow ◽  
Oroxylin A ◽  
Beneficial Effects ◽  
Isolated Hearts ◽  
Cardiac Functions ◽  
Coronary Endothelium

The mortality in septic patients with myocardial dysfunction is higher than those without it. Beneficial effects of flavonoid oroxylin A (Oro-A) on endotoxemic hearts were evaluated and compared with that of arginine vasopressin (AVP) which is used to reverse hypotension in septic patients. Endotoxemia in rats was induced by one-injection of lipopolysaccharides (LPS, 10 mg/kg, i.p.), and hearts were isolated 5-hrs or 16-hrs later. Isolated hearts with constant-pressure or constant-flow mode were examined by Langendorff technique. Rate and force of contractions of isolated atrial and ventricular strips were examined by tissue myography. Isolated endotoxemic hearts were characterized by decreased or increased coronary flow (CF) in LPS-treated-for-5hr and LPS-treated-for-16-hr groups, respectively, with decreased inotropy in both groups. Oro-A-perfusion ameliorated while AVP-perfusion worsened the decreased CF and inotropy in both preparations. Oro-A and AVP, however, did not affect diminished force or rate of contraction of atrial and ventricular strips of endotoxemic hearts. Oro-A-induced CF increase was not affected following coronary endothelium-denudation with saponin. These results suggest that Oro-A ameliorates LPS-depressed cardiac functions by increasing CF, leading to positive inotropy. In contrast, AVP aggravates cardiac dysfunction by decreasing CF. Oro-A is a potentially useful candidate for treating endotoxemia complicated with myocardial dysfunction.

scholarly journals Extracellular SPARC improves cardiomyocyte contraction during health and disease

2018 ◽  
Author(s):  
Sophie Deckx ◽  
Daniel M. Johnson ◽  
Marieke Rienks ◽  
Paolo Carai ◽  
Elza van Deel ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Cardiac Dysfunction ◽  
Matrix Protein ◽  
Contractile Function ◽  
Ex Vivo ◽  
Cardiac Fibroblasts ◽  
Cardiac Injury ◽  
Coxsackie Virus ◽  
Extracellular Matrix Protein

Secreted protein acidic and rich in cysteine (SPARC) is a non-structural extracellular matrix protein that regulates interactions between the matrix and neighboring cells. In the cardiovascular system, it is expressed by cardiac fibroblasts, endothelial cells, and in lower levels by ventricular cardiomyocytes. SPARC expression levels are increased upon myocardial injury and also during hypertrophy and fibrosis. We have previously shown that SPARC improves cardiac function after myocardial infarction by regulating post-synthetic procollagen processing, however whether SPARC directly affects cardiomyocyte contraction is still unknown. In this study we demonstrate a novel inotropic function for extracellular SPARC in the healthy heart as well as in the diseased state after myocarditis-induced cardiac dysfunction. We demonstrate SPARC presence on the cardiomyocyte membrane where it is co-localized with the integrin-beta1 and the integrin-linked kinase. Moreover, extracellular SPARC directly improves cardiomyocyte cell shortening ex vivo and cardiac function in vivo, both in healthy myocardium and during coxsackie virus-induced cardiac dysfunction. In conclusion, we demonstrate a novel inotropic function for SPARC in the heart, with a potential therapeutic application when myocyte contractile function is diminished such as that caused by a myocarditis-related cardiac injury.

Isolated hemoperfused heart model of slaughterhouse pigs

2001 ◽  
Vol 24 (4) ◽  
pp. 215-221 ◽  
Author(s):  
D. Modersohn ◽  
S. Eddicks ◽  
C. Grosse-Siestrup ◽  
I. Ast ◽  
S. Holinski ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Heart Function ◽  
Animal Experiments ◽  
Laboratory Animals ◽  
Coronary Perfusion ◽  
Balloon Catheters ◽  
Wide Range ◽  
Infusion Of Norepinephrine

A model of hemoperfused slaughterhouse pighearts is described providing a wide range of applications which leads to a reduction in animal experiments. The size of a pigheart, heart rate, coronary perfusion, metabolism, etc. are more comparable to conditions in patients than those in hearts of small laboratory animals. Global heart function can be assessed either by measuring stroke volume, ejection fraction, Emaxetc. in the working model or by measuring intraventricular pressure with balloon catheters in the isovolumetric model. Regional cardiac function can be measured by sonomicrometry and ischemic and non-ischemic areas can be compared. Local metabolic changes are measurable as well with microdialysis. Cardiac function can be kept on any given functional level by infusion of norepinephrine in spite of the fact that functional parameters are lower without adrenergic drive in vitro than in vivo. Stable heart function can be maintained for several hours with only 500 to 1000 ml of blood because the blood is permanently regenerated by a special dialysis system. This model can be applied in many research projects dealing with reperfusion injuries, inotropic, antiarrhythmic or arrhythmogenic effects of certain drugs, immunological rejection, evaluation of imaging systems (NMR, echocardiography etc.) or cardiac assist devices.

scholarly journals Mixture of MMP-2, MLC, and NOS Inhibitors Affects NO Metabolism and Protects Heart from Cardiac I/R Injury

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Anna Krzywonos-Zawadzka ◽  
Aleksandra Franczak ◽  
Grzegorz Sawicki ◽  
Iwona Bil-Lula
Keyword(s):  
Oxidative Stress ◽  
Cardiac Function ◽  
Ischemia Reperfusion Injury ◽  
Ex Vivo ◽  
Heart Function ◽  
Ischemia Reperfusion ◽  
Tissue Expression ◽  
Matrix Metalloproteinase 2 ◽  
No Production ◽  
Nos Inhibitors

Objectives. Coronary reperfusion procedure leads to ischemia/reperfusion injury of the heart (IRI). IRI arises from increased degradation of myosin light chains and increased activity of matrix metalloproteinase 2 (MMP-2). Increased production of toxic peroxynitrite (ONOO−) during oxidative stress is a source of increased nitration/nitrosylation of contractile proteins, which enhance their degradation through MMP-2. Hence, an imbalance in nitric oxide (NO) metabolism along with oxidative stress is an important factor contributing to pathophysiology of cardiovascular disorders, including myocardial infarction. The aim of the current study was to provide an important insight into understanding the interaction of iNOS, eNOS, and ADMA during oxidative stress and to propose the beneficial therapy to modulate this interaction. Material and Methods. Pathogen-free Wistar rats were used in this study as a surrogate heart model ex vivo. Rat hearts perfused using the Langendorff method were subjected to global no-flow ischemia with or without administration of DOXY (1 µM), ML-7 (0.5 µM), and L-NAME (2 µM) mixture. Haemodynamic parameters of heart function, markers of I/R injury, tissue expression of iNOS, eNOS, and phospho-eNOS, asymmetric dimethylarginine, and NO production as well as MMP-2 activity were measured. Results. Mechanical heart function and coronary flow (CF) were decreased in the hearts subjected to I/R. Treatment of the hearts with the tested mixture resulted in a recovery of mechanical function due to decreased activity of MMP‐2. An infusion of Doxy, ML-7, and L-NAME mixture into I/R hearts decreased the expression of iNOS, eNOS, and phospho-eNOS and in consequence reduced ADMA expression. Decreased ADMA production led to enhanced NO synthesis and improvement of cardiac function at 85% of aerobic control. Conclusions. Synergistic effect of the multidrug therapy with the subthreshold doses allows addressing a few pathways of I/R injury simultaneously to achieve protection of cardiac function during I/R.

Abstract 50: Therapeutic Silencing of miRNA-652 Restores Cardiac Function and Attenuates Pathological Remodeling in a Mouse Model of Pressure Overload

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Bianca C Bernardo ◽  
Sally S Nguyen ◽  
Catherine E Winbanks ◽  
Xiao-Ming Gao ◽  
Esther J Boey ◽  
...  
Keyword(s):  
Heart Failure ◽  
Mouse Model ◽  
Cardiac Function ◽  
Cardiac Dysfunction ◽  
Heart Function ◽  
Pressure Overload ◽  
Post Treatment ◽  
Locked Nucleic Acid ◽  
Luciferase Assay ◽  
Sham Operation

Introduction: Targeting microRNAs differentially regulated in settings of stress and protection could represent a new approach for the treatment of heart failure. miR-652 expression increased in hearts of a cardiac stress mouse model and was downregulated in a model of cardiac protection. Aim: To assess the therapeutic potential of silencing miR-652 in a mouse model with established pathological hypertrophy and cardiac dysfunction due to pressure overload. Methods: Mice were subjected to a sham operation (n=10) or transverse aortic constriction (TAC, n=14) for 4 weeks to induce hypertrophy and cardiac dysfunction. Mice were subcutaneously administered a locked nucleic acid (LNA)-antimiR-652 or LNA-control. Cardiac function was assessed by echocardiography before and 8 weeks post treatment, followed by molecular and histological analyses. Results: Expression of miR-652 increased in hearts subjected to pressure overload compared to sham operated mice (2.9 fold, n=3-5, P<0.05), but was silenced in hearts of mice administered LNA-antimiR-652 (95% decrease, n=3-7, P<0.05). In mice subjected to pressure overload, inhibition of miR-652 improved cardiac function (29±1% at 4 weeks post TAC compared to 35±1% post treatment, n=7, P<0.001) and attenuated cardiac hypertrophy. Functional and morphologic improvements in hearts of treated mice were associated with reduced cardiac fibrosis, apoptosis, cardiomyocyte size; decreased B-type natriuretic peptide gene expression; and preserved angiogenesis (all P<0.05, n=4-7/group). Mechanistically, we identified Jagged1, a Notch1 ligand, as a direct target of miR-652 by luciferase assay. Jagged1 and Notch1 mRNA were upregulated in hearts of TAC treated mice (1.2-1.7 fold, n=7, P<0.05). Importantly, chronic knockdown of miR-652 was not associated with any notable toxicity in other tissues. Conclusion: Therapeutic silencing of miR-652 protects the heart against pathological cardiac remodeling and improves heart function via mechanisms that are associated with preserved angiogenesis, decreased fibrosis and upregulation of a miR-652 target, Jagged1. These studies provide the first evidence that targeted inhibition of miR-652 could represent an attractive approach for the treatment of heart failure.

Abstract 519: Talin is Required for Normal Adult Heart Function

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Yoshitake Cho ◽  
Ruixia Li ◽  
Ana M Manso ◽  
Robert S Ross
Keyword(s):  
Heart Failure ◽  
Cardiac Function ◽  
Cardiac Dysfunction ◽  
Cardiac Development ◽  
Heart Function ◽  
Left Ventricular ◽  
Mass Spectrometry Analysis ◽  
Adult Heart ◽  
Spectrometry Analysis ◽  
Functional Changes

Talin (Tln) is a component of muscle costameres that links integrins to other components of the cellular cytoskeleton and plays an important role in maintaining the cellular integrity of cardiac myocytes (CM). There are two talin genes, Tln1 and Tln2, expressed in the heart. Tln1 is ubiquitously expressed, and Tln2 is dominantly expressed in CM. In our previous study, we show that the global deletion of Tln2 in mice (T2KO) caused no structural or functional changes in the heart, presumably because CM Tln1 became up-regulated. However, we found that mice lacking both CM Tln1 and Tln2 exhibit cardiac dysfunction by 4 weeks (w) of age with 100% mortality by 6 months (m), showing Tln plays an essential role in cardiac development and in maintaining cardiac function. In this study, we produced a tamoxifen (Tamo)-inducible mouse model in which Tln1 could be explicitly reduced in the adult CM (T1icKO), and then generate T1icKO:T2KO (T1/2dKO), so that the function of Tln could be assessed in the postnatal heart. T2KO and Tln1/2dKO mice were injected with Tamo at 8w. Echocardiograms were performed to evaluate cardiac function up to 8w post-Tamo injection. While T2KO mice showed normal cardiac function, T1/2dKO exhibited a gradual decrease in function post-Tamo injection. At 8w post-Tamo injection, T1/2dKO mice showed cardiac hypertrophy, fibrosis, and heart failure. To understand the mechanism by which deletion CM talin leads to cardiac dysfunction, left ventricular tissue protein lysates from T2KO and T1/2dKO mice at 4w post-Tamo when cardiac function (echo) and structure were preserved in dKO. The protein lysates were subjected to quantitative mass spectrometry analysis. We found there are 1,100 proteins differentially expressed in T2KO and T1/2dKO hearts. Pathway analysis was performed, and the results showed that proteins involved in vesicle transport, protein folding, and innate immunity are most up-regulated in the T1/2dKO heart. Taken together, our results show that Tln is required for maintaining proper cardiac function in the adult heart. The deletion of Tln in CM results in the up-regulation of multiple intracellular pathways, and we are currently studying the role of each pathway in the pathogenesis of heart failure induced by CM Tln deletion.

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