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.

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.

Co-expression of skeletal and cardiac troponin T decreases mouse cardiac function

2008 ◽  
Vol 294 (1) ◽  
pp. C213-C222 ◽  
Author(s):  
Q.-Q. Huang ◽  
H. Z. Feng ◽  
J. Liu ◽  
J. Du ◽  
L. B. Stull ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Contractile Function ◽  
Troponin T ◽  
Ex Vivo ◽  
Heart Function ◽  
Left Ventricular Pressure ◽  
Experimental System ◽  
Left Ventricular ◽  
Negative Effects

In contrast to skeletal muscles that simultaneously express multiple troponin T (TnT) isoforms, normal adult human cardiac muscle contains a single isoform of cardiac TnT. To understand the significance of myocardial TnT homogeneity, we examined the effect of TnT heterogeneity on heart function. Transgenic mouse hearts overexpressing a fast skeletal muscle TnT together with the endogenous cardiac TnT was investigated in vivo and ex vivo as an experimental system of concurrent presence of two classes of TnT in the adult cardiac muscle.This model of myocardial TnT heterogeneity produced pathogenic phenotypes: echocardiograph imaging detected age-progressive reductions of cardiac function; in vivo left ventricular pressure analysis showed decreased myocardial contractility; ex vivo analysis of isolated working heart preparations confirmed an intrinsic decrease of cardiac function in the absence of neurohumoral influence. The transgenic mice also showed chronic myocardial hypertrophy and degeneration. The dominantly negative effects of introducing a fast TnT into the cardiac thin filaments to produce two classes of Ca2+ regulatory units in the adult myocardium suggest that TnT heterogeneity decreases contractile function by disrupting the synchronized action during ventricular contraction that is normally activated as an electrophysiological syncytium.

Abstract 1281: Human Adipose Tissue-derived Stem Cells Potently Preserve Cardiac Function Resulting From Permanently Induced Myocardial Ischemia

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Liying Cai ◽  
Brian H Johnstone ◽  
Todd G Cook ◽  
Keith L March
Keyword(s):  
Stem Cells ◽  
Adipose Tissue ◽  
Cardiac Function ◽  
Heart Function ◽  
Human Adipose Tissue ◽  
Functional Improvement ◽  
Saline Control ◽  
Control Group

Background The use of stem cells has gained much interest as a potential therapeutic approach for repair of damage caused by a variety of cardiac insults. We and others have demonstrated the ability of pluripotent adipose-derived stem cells (ASCs), to promote repair in ischemic skeletal tissues. Here we demonstrate that ASCs also stimulate a robust functional improvement following acute myocardial infarction (MI) in rats. Methods and Results ASCs were harvested from human subcutaneous adipose tissue. ASCs were characterized in vitro before in vivo testing. Growth and metabolic activity of human microvascular endothelial cells (HMVEC) cultured in growth-factor deficient minimal medium (MM) increased 1.7-fold when supplemented with a 1:1 mixture of ASC CM ( p <0.01). Sprout formation by HMVECs and migration of endothelial progenitor cell (EPC) was enhanced by 2.1 and 2.0-fold, repectively, when ASC CM was added to MM ( p <0.01). Following demonstration of potency in vitro, the ASCs were evaluated for the ability to protect and rescue ischemic myocardium in an athymic nude rat following permanent ligation of the proximal LAD region. Immediately after ligation 10 6 ASCs in 100 μl saline or carrier alone was injected into 2 sites of the peri-infarct region, then at 4 and 28 d heart function was evaluated echocardiography using a Visualsonics Vivo770. ASC-treated rats consistently exhibited better cardiac function at 1 month compared to the saline control group. LV ejection fraction of the ASC group was 56 ± 7% (mean ± SEM) vs 37 ± 3% for the control (p<0.04). Fractional shortening was 32 ± 5% (ASC) vs 19 ± 2% (p<0.04). LV volumes both at end-diastolic and end-systolic stages were lower in ASC group (311 ± 17 μl and 139 ± 21 μl, respectively) than saline group (391 ± 30 μl and 249 ± 27 μl) (p<0.03). Anterior wall thinning was attenuated in ASC group (1.6 ± .08 mm vs 1.2 ± .2, at end-diastole, p<0.03). Post-mortem histological analysis demonstrated that ASC treated hearts had lower fibrosis (26 ± 6% vs 34 ± 6%; p<0.05). Conclusion We have demonstrated that ASCs have great potential as a cell therapy to preserve heart function following ischemic insult. Given the abundant source of ASCs, therapies with these cells have a higher potential for widespread adoption compared to more rare cell types.

Ethanol Extract of Achillea fragrantissima Enhances Angiogenesis through Stimulation of VEGF Production

2020 ◽  
Vol 21 ◽  
Author(s):  
Hana M. Hammad ◽  
Amer Imraish ◽  
Maysa Al-Hussaini ◽  
Malek Zihlif ◽  
Amani A. Harb ◽  
...  
Keyword(s):  
Wound Healing ◽  
Rural Communities ◽  
Ex Vivo ◽  
Ethanol Extract ◽  
Aortic Ring ◽  
Treated Group ◽  
Control Group ◽  
Dependent Manner ◽  
Achillea Fragrantissima

Objective: Achillea fragrantissima L. (Asteraceae) is a traditionally used medicinal herb in the rural communities of Jordan. Methods: The present study evaluated the efficacy of the ethanol extract of this species on angiogenesis in both, ex vivo using rat aortic ring assay and in vivo using rat excision wound model. Results: In concentrations of 50 and 100 µg/ml, the ethanol extract showed angiogenic stimulatory effect and significantly increased length of capillary protrusions around aorta rings of about 60% in comparison to those of untreated aorta rings. In MCF-7 cells, the ethanol extract of A. fragrantissima stimulates the production of VEGF in a dose-dependent manner. 1% and 5% of ethanol extract of A. fragrantissima containing vaseline based ointment was applied on rat excision wounds for six days and was found to be effective in wound healing and maturation of the scar. Both preparations resulted in better wound healing when compared to the untreated control group and vaseline-treated group. This effect was comparable to that induced by MEBO, the positive control. Conclusion: The results indicate that A. fragrantissima has a pro-angiogenic effect, which may act through the VEGF signaling pathway.

scholarly journals Influence of genetic background on ex vivo and in vivo cardiac function in several commonly used inbred mouse strains

2010 ◽  
Vol 42A (2) ◽  
pp. 103-113 ◽  
Author(s):  
Matthew S. Barnabei ◽  
Nathan J. Palpant ◽  
Joseph M. Metzger
Keyword(s):  
Cardiac Function ◽  
Genetic Divergence ◽  
Ex Vivo ◽  
Inbred Mouse ◽  
Critical Role ◽  
Inbred Strains ◽  
Mouse Strains ◽  
Inbred Mouse Strains ◽  
Cardiac Decompensation

Inbred mouse strains play a critical role in biomedical research. Genetic homogeneity within inbred strains and their general amenability to genetic manipulation have made them an ideal resource for dissecting the physiological function(s) of individual genes. However, the inbreeding that makes inbred mice so useful also results in genetic divergence between them. This genetic divergence is often unaccounted for but may be a confounding factor when comparing studies that have utilized distinct inbred strains. Here, we compared the cardiac function of C57BL/6J mice to seven other commonly used inbred mouse strains: FVB/NJ, DBA/2J, C3H/HeJ, BALB/cJ, 129X1/SvJ, C57BL/10SnJ, and 129S1/SvImJ. The assays used to compare cardiac function were the ex vivo isolated Langendorff heart preparation and in vivo real-time hemodynamic analysis using conductance micromanometry. We report significant strain-dependent differences in cardiac function between C57BL/6J and other commonly used inbred strains. C57BL/6J maintained better cardiac function than most inbred strains after ex vivo ischemia, particularly compared with 129S1/SvImJ, 129X1/SvJ, and C57BL/10SnJ strains. However, during in vivo acute hypoxia 129X1/SvJ and 129S1/SvImJ maintained relatively normal cardiac function, whereas C57BL/6J animals showed dramatic cardiac decompensation. Additionally, C3H/HeJ showed rapid and marked cardiac decompensation in response to esmolol infusion compared with effects of other strains. These findings demonstrate the complex effects of genetic divergence between inbred strains on cardiac function. These results may help inform analysis of gene ablation or transgenic studies and further demonstrate specific quantitative traits that could be useful in discovery of genetic modifiers relevant to cardiac health and disease.

scholarly journals Proinflammatory Cytokines Are Soluble Mediators Linked with Ventricular Arrhythmias and Contractile Dysfunction in a Rat Model of Metabolic Syndrome

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Evaristo Fernández-Sada ◽  
Alejandro Torres-Quintanilla ◽  
Christian Silva-Platas ◽  
Noemí García ◽  
B. Cicero Willis ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Ventricular Arrhythmias ◽  
Mechanical Performance ◽  
Contractile Function ◽  
Ex Vivo ◽  
Heart Function ◽  
Control Group ◽  
Serum Triglycerides ◽  
Rat Cardiomyocytes ◽  
Proinflammatory Mediators

Metabolic syndrome (MS) increases cardiovascular risk and is associated with cardiac dysfunction and arrhythmias, although the precise mechanisms are still under study. Chronic inflammation in MS has emerged as a possible cause of adverse cardiac events. Male Wistar rats fed with 30% sucrose in drinking water and standard chow for 25–27 weeks were compared to a control group. The MS group showed increased weight, visceral fat, blood pressure, and serum triglycerides. The most important increases in serum cytokines included IL-1β(7-fold), TNF-α(84%), IL-6 (41%), and leptin (2-fold), the latter also showing increased gene expression in heart tissue (35-fold). Heart function ex vivo in MS group showed a decreased mechanical performance response to isoproterenol challenge (ISO). Importantly, MS hearts under ISO showed nearly twofold the incidence of ventricular fibrillation. Healthy rat cardiomyocytes exposed to MS group serum displayed impaired contractile function and Ca2+handling during ISO treatment, showing slightly decreased cell shortening and Ca2+transient amplitude (23%), slower cytosolic calcium removal (17%), and more frequent spontaneous Ca2+release events (7.5-fold). As spontaneous Ca2+releases provide a substrate for ventricular arrhythmias, our study highlights the possible role of serum proinflammatory mediators in the development of arrhythmic events during MS.

scholarly journals Therapeutic Inhibition of Acid Sensing Ion Channel 1a Recovers Heart Function After Ischemia-Reperfusion Injury

Circulation ◽  
2021 ◽  
Author(s):  
Meredith A. Redd ◽  
Sarah E. Scheuer ◽  
Natalie J. Saez ◽  
Yusuke Yoshikawa ◽  
Han Sheng Chiu ◽  
...  
Keyword(s):  
Ion Channel ◽  
Reperfusion Injury ◽  
Electromechanical Coupling ◽  
Ischemia Reperfusion Injury ◽  
Ex Vivo ◽  
Heart Function ◽  
Ischemia Reperfusion ◽  
Genetic Ablation ◽  
Organ Level

Background: Ischemia-reperfusion injury (IRI) is one of the major risk factors implicated in morbidity and mortality associated with cardiovascular disease. During cardiac ischemia, the build-up of acidic metabolites results in decreased intracellular and extracellular pH that can reach as low as 6.0-6.5. The resulting tissue acidosis exacerbates ischemic injury and significantly impacts cardiac function. Methods: We used genetic and pharmacological methods to investigate the role of acid sensing ion channel 1a (ASIC1a) in cardiac IRI at the cellular and whole organ level. Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) as well as ex vivo and in vivo models of IRI were used to test the efficacy of ASIC1a inhibitors as pre- and post-conditioning therapeutic agents. Results: Analysis of human complex trait genetics indicate that variants in the ASIC1 genetic locus are significantly associated with cardiac and cerebrovascular ischemic injuries. Using hiPSC-CMs in vitro and murine ex vivo heart models, we demonstrate that genetic ablation of ASIC1a improves cardiomyocyte viability after acute IRI. Therapeutic blockade of ASIC1a using specific and potent pharmacological inhibitors recapitulates this cardioprotective effect. We used an in vivo model of myocardial infarction (MI) and two models of ex vivo donor heart procurement and storage as clinical models to show that ASIC1a inhibition improves post-IRI cardiac viability. Use of ASIC1a inhibitors as pre- or post-conditioning agents provided equivalent cardioprotection to benchmark drugs, including the sodium-hydrogen exchange inhibitor zoniporide. At the cellular and whole organ level, we show that acute exposure to ASIC1a inhibitors has no impact on cardiac ion channels regulating baseline electromechanical coupling and physiological performance. Conclusions: Collectively, our data provide compelling evidence for a novel pharmacological strategy involving ASIC1a blockade as a cardioprotective therapy to improve the viability of hearts subjected to IRI.

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