Protective effect of superoxide dismutase(SCD) and subtrates on acute ischemic and reperfused myocardium was assessed by cardiac microdialysis. 30 Rabbits were divided into 4 groups; normal control group(group I, n=5), ischemic group(group II,
n=5), SOD
treated group (group III, n=10), and substrates treated group (group IV, n=10).
After a microdialysis apparatus was implanted in rabbit myocardium, coronary artery was occuluded for 5 minutes and reperfusion was performed for 30 minutes.
Hemodynamic changes, CK-MB isoenzyme level and adenine ring compound level in effluent dialysates(equilibrated with interstitial fluld), and ultrastructural changes of myocardial cell were analysed.
Systolic blood pressure at 10 and 30 minutes after reperfusion was higher in group III and IV than in group II(p<.05). Also percent recovery of systolic blood pressure in group III9p<.01) and IV(p<.02) was higher than in group II. CK-MB isoenzyme
level
in effluent dialysates was peaked at 10 minutes after reperfusion, thereafter decreased in group II, III and IV. At 30 minutes after reperfusion, its level was lower in group III and IV than in group II(p<.05). Adenine ring compound level in
effluent
dialysates increased till 10 minutes after reperfusion and progressively decrease. At 10 and 30 minutes after reperfusion, its level was lower in group III and IV than in group II without significance. Degree of myocardial damage was estimated by
scoring of mitochondrial injury. Group I was within normal range and most severe injury was seen in group II. And the score of mitochondrial injury in group III and IV was lower than in group II.
In conclusion, SOD and substrates (KMP solution) had protective effect on stunned myocardium. The microdialysis appratus was a good device for studying stunned myocardium, and cardiac microdialysis might be a unique technique for analysis of
regional
intramyocardial interstitial fluid. (Korean J Thoracic Cardiovas Surg 1994; 27:441-451)
|