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Acta Physiologica 2011; Volume 203, Supplement 686
Joint Congress of FEPS and Turkish Society of Physiological Sciences
9/3/2011-9/7/2011
Istanbul, Turkey
THE IMPORTANCE OF TIMING FOR MAGNESIUM OROTATE-INDUCED CARDIOPROTECTION DURING POST-ISCHAEMIC REPERFUSION IN ISOLATED RAT HEARTS
Abstract number: PC211
Nicoleta Mirica1 Silvia, Gheorgheosu1 Dorina Elena, Maria Duicu1 Oana, Ionela Anechitei1 Andreea, Danila1 Maria, Fira Mladinescu1 Ovidiu, Angoulvant2 Denis, Danina Muntean1 Mirela
1Department of Pathophysiology, University of Medicine and Pharmacy Timisoara, Romania
2Inserm U1060 CarMeN, University Lyon 1, Hpitaux de Lyon, Lyon, France
Objective:
Acute administration of magnesium orotate (Mg-Or) at reperfusion has been previously shown to elicit significant protection in isolated rat hearts. We hypothesized that Mg-Or (1mM) induced cardioprotection against post-ischemic reperfusion injuries depends on the timing of intervention.
Methods:
Isolated male rat hearts (n = 68/group) were subjected to 30 min global ischaemia followed by 120 min reperfusion. They were randomized to receive: (i) no additional intervention (Ctrl); (ii) early administration of Mg-Or, 2 minutes before the onset of reperfusion (Mg-Or-E) and (iii) delayed administration of Mg-Or 3 minutes after the onset of reperfusion (Mg-Or-D). Functional recovery was assessed after 30 min of reperfusion by measuring the functional parameters: LVDP, contractility (dP/dtmax) and relaxation (dP/dtmin) indices. Infarct size (IS) was measured by TTC staining.
Results:
Significant protection of ventricular function was observed in Mg-Or-E vs. Ctrl group: LVDP (67.8+/-2.8% vs. 39.2+/-3.2, p < 0.001), dP/dtmax (61.5+/-2.9% vs. 38.8+/-4.6%, p < 0.01) and dP/dtmin (72+/-4.45% vs. 47.6+/-4.6%, p < 0.01). In Mg-Or-D group important albeit less significant protection of systolic function was present whereas no protection was observed for the relaxation index. Mg-Or induced significant IS reduction in both treated groups as compared to Ctrl (Mg-Or-E, 32.07+/-1.8%, Mg-Or-D, 35+/-3% vs. Ctrl 70.4+/-3.7%, p < 0.001).
Conclusions:
Early administration of Mg-Or before the onset of reperfusion reduces infarct size in the same magnitude as delayed administration, but induces significantly better recovery of myocardial function.Early administration of Mg-Or during the postischaemic reperfusion may also have beneficial effects on non-infarcted dysfunctional cardiomyocytes (stunned myocardium). Research supported by National Authority for Scientific Research grant 42-122/2008, Hungary-Romania Cross-Border Cooperation HURO/0802/011
To cite this abstract, please use the following information:
Acta Physiologica 2011; Volume 203, Supplement 686 :PC211