Cardioprotective effect of N-methylnicotinamide salt of pyruvate in experimental model of cardiac hypoxia

BACKGROUND

Pyruvate improves contractility of normal, hypoxic, and post-ischemic myocardium. However, sodium overload is a major problem with its therapeutic application if sodium pyruvate is used. Development of alternative forms such as N-1-methylnicotinamide (MNA) pyruvate may help to overcome this problem. The aim of the study was to investigate the effect of MNA pyruvate in a murine model of cardiac ischemia.

METHODS

Seven month old male ApoE^-/-LDLr^-/- mice that develop myocardial infarction when exposed to hypoxic stress, were used in this study. Hypoxia (8% O2 in inspired air) was maintained for 8min and was followed by reoxygenation (21% O2 in inspired air). Four groups of mice were treated 10min before the hypoxic event by intravenous injection of MNA, MNA pyruvate, sodium pyruvate, and saline as control. The myocardial ischemia and damage was recorded by ECG. Four hours following the hypoxic episode serum troponin T and creatine kinase activity were measured.

RESULTS

Significant hypernatremia was found in the sodium pyruvate group. During hypoxia, control and MNA group developed profound STU depressions on ECG while no changes were observed in MNA pyruvate and sodium pyruvate group. Creatine kinase activity and troponin T content in the mice plasma were significantly higher in the control and MNA group as compared to the MNA pyruvate and sodium pyruvate group.

CONCLUSIONS

This study demonstrated that administration of MNA pyruvate prior to a hypoxia-induced cardiac event was cardioprotective. This intervention did not cause hypernatremia in contrast to sodium pyruvate.

PET Imaging of Cardiac Hypoxia: Hitting Hypoxia Where It Hurts

Purpose of Review

In this review, we outline the potential for hypoxia imaging as a diagnostic and prognostic tool in cardiology. We describe the lead hypoxia PET radiotracers currently in development and propose a rationale for how they should most appropriately be screened and validated.

Recent Findings

While the majority of hypoxia imaging agents has been developed for oncology, the requirements for hypoxia imaging in cardiology are different. Recent work suggests that the bis(thiosemicarbazone) family of compounds may be capable of detecting the subtle degrees of hypoxia associated with cardiovascular syndromes, and that they have the potential to be “tuned” to provide different tracers for different applications.

Summary

New tracers currently in development show significant promise for imaging evolving cardiovascular disease. Fundamental to their exploitation is their careful, considered validation and characterization so that the information they provide delivers the greatest prognostic insight achievable.