using-an-isolated-working-rat-heart-model-to-test-donor-heart

Using an Isolated Working Rat Heart Model to Test Donor Heart Preservation Strategies

Optimization of donor heart preservation solutions has played a key role in reducing ischemia-reperfusion injury in donor hearts during organ retrieval, ...

Victor Chang Cardiac Research Institute

University of New South Wales

Storage of donor hearts in cardioplegic solutions supplemented with conditioning agents activating endogenous mitochondrial protective signaling enhanced their postreperfusion recovery. The present study investigates the role of timing and duration of cardiac exposure to cyclosporine A (CsA), another putative mitochondrial protectant, on cardiac functional recovery and potential mechanisms of CsA action in an isolated working rat heart model of donor heart retrieval and storage.

Cyclosporine A as a Cardioprotective Agent During Donor Heart Retrieval, Storage, or Transportation: Benefits and Limitations.

Administration of anti-CD40 ligand (CD40L) antibodies has been reported to allow long-term islet allograft survival in non-human primates without the need for exogenous immunosuppression. However, the use of anti-CD40L antibodies was associated with thromboembolic complications. Targeting downstream intracellular components shared between CD40 and other TNF family co-stimulatory molecules could bypass these complications. TNF receptor associated factor 2 (TRAF2) integrates multiple TNF receptor family signalling pathways that are critical for T cell activation and may be a central node of alloimmune responses.

Targeted deletion of Traf2 allows immunosuppression-free islet allograft survival in mice.

The ryanodine receptor antagonist dantrolene inhibits calcium release from the sarcoplasmic reticulum and reduces cardiac ischaemia-reperfusion injury (IRI) in global warm ischaemia models however the cardioprotective potential of dantrolene under hypothermic conditions is unknown. This study addresses whether the addition of dantrolene during cardioplegia and hypothermic storage of the donor heart can improve functional recovery and reduce IRI. Using an ex vivo isolated working heart model, Wistar rat (3 month and 12 month) hearts were perfused to acquire baseline haemodynamic measurements of aortic flow, coronary flow, cardiac output, pulse pressure and heart rate. Hearts were arrested and stored in Celsior preservation solution supplemented with 0.2-40 μM dantrolene for 6 hours at 4°C, then reperfused (15 min Langendorff, 30 min working mode). In 3-month hearts, supplementation with 1 μM dantrolene significantly improved aortic flow and cardiac output compared to unsupplemented controls however lactate dehydrogenase (LDH) release and contraction bands were comparable. In contrast, 40 μM dantrolene-supplementation yielded poor cardiac recovery, increased post-reperfusion LDH but reduced contraction bands. All 3-month hearts stored in dantrolene displayed significantly reduced cleaved-caspase 3 intensities compared to controls. Analysis of cardioprotective signalling pathways showed no changes in AMPKα however dantrolene increased STAT3 and ERK1/2 signaling in a manner unrelated to functional recovery and AKT activity was reduced in 1 μM dantrolene-stored hearts. In contrast to 3-month hearts, no significant improvements were observed in the functional recovery of 12-month hearts following prolonged storage in 1 μM dantrolene.

Functional recovery after dantrolene-supplementation of cold stored hearts using an ex vivo isolated working rat heart model.

The cardioprotective potential of the sodium-glucose cotransporter 2 inhibitor empagliflozin in donor heart preservation.

Hearts from older donors or procured via donation after circulatory death (DCD) can alleviate transplant waitlist; however, these hearts are particularly vulnerable to injury caused by warm ischemic times (WITs) inherent to DCD. This study investigates how the combination of increasing donor age and pharmacologic supplementation affects the ischemic tolerance and functional recovery of DCD hearts and how age impacts cardiac mitochondrial respiratory capacity and oxidative phosphorylation.

The Effect of Increasing Donor Age on Myocardial Ischemic Tolerance in a Rodent Model of Donation After Circulatory Death.

Ischemia-reperfusion injury (IRI) is one of the major risk factors implicated in morbidity and mortality associated with cardiovascular disease. During cardiac ischemia, the buildup of acidic metabolites results in decreased intracellular and extracellular pH, which can reach as low as 6.0 to 6.5. The resulting tissue acidosis exacerbates ischemic injury and significantly affects cardiac function.

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

Frailty is prevalent in patients with heart failure (HF) and associated with increased morbidity and mortality. Hence, there has been increased interest in the reversibility of frailty following treatment with medication or surgery. This systematic review aimed to assess the reversibility of frailty in patients with HF before and after surgical interventions aimed at treating the underlying cause of HF. It also aimed to assess the efficacy of cardiac rehabilitation and prehabilitation in reversing or preventing frailty in patients with HF.

Jeanette E. Villanueva

Cardiac Physiology and Transplantation

Victor Chang Cardiac Research Institute

Using an Isolated Working Rat Heart Model to Test Donor Heart Preservation Strategies

Jeanette E. Villanueva

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Cardiac Physiology and Transplantation

Victor Chang Cardiac Research Institute

Using an Isolated Working Rat Heart Model to Test Donor Heart Preservation Strategies

Cardiac Physiology and Transplantation