Protective Effect on the Rat's Myocardium with Changes in Magnesium Concentrations

Hong, Chi Wook; Cho, Kyu Seok; You, Seh Young

Abstract

The increasing use of coronary perfusates for the protection of the human heart during ischemic cardiac arrest has placed great emphasis on the need for a rational and safe formulation. For the purpose of this study isolated rat hearts were connected to retrograde nonworking perfusion system proposed by Langendorff, and then perfused for 20 minutes by coronary infusates of magnesium concentration of 1.66 m Mol per liter (groupA, n=10) or 15 mMol per liter (groupB, n=10). After 20 minutes perfusion, cold cardioplegic solution (modified St. Thomas' Hospital solution) was infused for 2 minutes, and prepared within 4degrees C Krebs-Henseleit solution. Finally, 20 minutes of cononay reprsfusion was reestablished after l hour of cold ischemic cardiac arrest. Hemodynamic parameters (heart rate, left ventricular pressure, +/-dp/dt max. and coronany flow) and enzymes assay (creatine phosphokinase, lactic dehydrogenase and glutamic oxaloacetic transaminase) were performed each other at which rat heart was perfused for 20 minutes and reperfused for 20 minutes thereafter. There were significant differences in the recovery rate of heart rate, systolic left ventricular pressure, +dp/dt max, and coronary flow and reperfusion-perfusion ratio of creatine phosphokinase(P<0.05). But, there were no significant differences in the recovery rate of -dp/dt max, and reperfusion-perfusion ratio of lactic dehydrogenase and glutamic oxaloacetic acid(P>0.05).