Effects of magnesium supplementation in a porcine model of myocardial ischemia and reperfusion

• Published in: Journal of cardiovascular pharmacology Vol. 24; no. 4; p. 603
• Main Authors: Atar, D, Serebruany, V, Poulton, J, Godard, J, Schneider, A, Herzog, W R
• Format: Journal Article
• Language: English
• Published: United States 01-10-1994
• Subjects: Animals; Female; Hemodynamics - drug effects; Infusions, Intravenous; Magnesium - blood; Magnesium - therapeutic use; Models, Cardiovascular; Myocardial Contraction - drug effects; Myocardial Ischemia - prevention & control; Myocardial Reperfusion; Myocardial Stunning - prevention & control; Platelet Aggregation - drug effects; Swine
• ISSN: 0160-2446
• DOI: 10.1097/00005344-199410000-00011

We tested the hypothesis that acute, intravenous (i.v.) magnesium (Mg2+) supplementation would protect against myocardial stunning in an in situ swine model of regional ischemia and reperfusion and that a concomitant inhibitory effect on platelet aggregation would be elicited. An open-chest model was used, with transient occlusion of the left anterior descending coronary artery (LAD) for 8 min. Regional contractile function was assessed by measuring wall thickening fraction with epicardial Doppler crystals. One control group (n = 6) and two treatment groups were studied: group I (n = 6) received 750 mg MgSO4 before occlusion; group II (n = 6) received 1 g MgSO4 after the occlusion. Both protocols produced significant hypermagnesemia. In group I, platelet aggregation was measured before and after Mg2+ treatment using platelet-rich plasma (PRP) and various agonists (ADP 5 and 10 mM and collagen 1 mg/ml). As compared with controls, both treatment groups experienced significantly less postischemic dysfunction, with systolic function returning more quickly to baseline. Furthermore, platelet aggregation was significantly decreased immediately after Mg2+ infusion. Inhibition of platelet aggregation induced by Mg2+ treatment occurs concomitantly with significant amelioration of postischemic myocardial dysfunction.