Pharmacological preconditioning with monophosphoryl lipid A improves post ischemic diastolic function and modifies TNF-alpha synthesis

Ram Sharony*, Inna Frolkis, Dvir Froylich, Stephan M. Wildhirt, Itzhak Shapira, Bruno Reichart, Nahum Nesher, Gideon Uretzky

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Objective: Pharmacologic preconditioning represents an attractive myocardial protection strategy. Tumor necrosis factor-alpha plays an important role in myocardial ischemia-reperfusion injury. We aimed to determine the effect of Monophosphoryl lipid A-induced delayed preconditioning on diastolic and systolic left ventricular function and tumor necrosis factor-alpha synthesis during ischemia and reperfusion. Methods: Rats (n=10) were pretreated with Monophosphoryl lipid A (350 μg/kg) or vehicle (n=9). Twenty-four hours later, the hearts were isolated and perfused on a Langendorff apparatus. Hemodynamic measurements, tumor necrosis factor-alpha mRNA expression and protein content were studied after stabilization (baseline), after 35 min of global ischemia and at 40 min of reperfusion. Results: Left ventricular developed pressure and peak rate of left ventricular developed pressure (dP/dt) rise were comparable between the animals in the control and Monophosphoryl lipid A treated groups during baseline but were higher in Monophosphoryl lipid A group at reperfusion (74±4 vs 51±5 mmHg, 3340±172 vs 2240±156 mmHg/s, respectively, P<0.01). dP/dt fall was significantly lower in the MLA group (2630±225 v 1580±210 mmHg/s, P<0.01) at 40 min of reperfusion as well as end diastolic pressure. Baseline tumor necrosis factor-alpha mRNA (expressed as arbitrary densitometry units) were higher in the Monophosphoryl lipid A group (1.3±0.1 vs 0.5±0.03, P<0.05) but remained constant after ischemia and reperfusion (1.3±0.1 and 1.4±0.03, P=0.2), while further increase was observed in the control group (from 1.0±0.1 to 1.4±0.1, P<0.05). Tumor necrosis factor-alpha protein content from heart effluent in the control group was increased during reperfusion (79±30 and 200±22 pg/ml, P<0.05) but was undetectable in the Monophosphoryl lipid A group. Marked TNF-alpha immunostaining of left ventricular tissue was observed only in the control group but no TNF-alpha staining was evident in the Monophosphoryl lipid A treated group at 40 min of reperfusion. Conclusion: Monophosphoryl lipid A-induced preconditioning renders the heart more tolerant to ischemia-reperfusion in terms of left ventricular diastolic and systolic function, and prevents tumor necrosis factor-alpha production during ischemia, through aborting the translation phase of tumor necrosis factor-alpha synthesis.

Original languageEnglish
Pages (from-to)501-507
Number of pages7
JournalEuropean Journal of Cardio-thoracic Surgery
Volume27
Issue number3
DOIs
StatePublished - Mar 2005

Funding

FundersFunder number
Germany-Israel Foundation

    Keywords

    • Ischemia-reperfusion
    • Preconditioning
    • TNF-alpha

    Fingerprint

    Dive into the research topics of 'Pharmacological preconditioning with monophosphoryl lipid A improves post ischemic diastolic function and modifies TNF-alpha synthesis'. Together they form a unique fingerprint.

    Cite this