Effect of creatine phosphate on myocardial injury induced by lung ischemia-reperfusion in rats

Abstract

Objective To evaluate the effect of creatine phosphate on the myocardial injury induced by lung ischemia-reperfusion (I/R) in rats. Methods Twenty-four male Sprague-Dawley rats, aged 8-10 weeks, weighing 250-350 g, were randomly divided into 3 groups (n=8 each) using a random number table: sham operation group (group S), I/R group, and I/R+ creatine phosphate group (group CP). Lung I/R was induced by clamping the left hilum of lung for 0.5 h with a non-invasive microvascular clip followed by mechanical ventilation and 2.0 h of reperfusion.Creatine phosphate 6.6 mg·kg-1·min-1 were infused intravenously at 30 min before ischemia in group CP, while the equal volume of normal saline was administered in group I/R.At 2.0 h of reperfusion, blood samples were obtained from the right ventricle for determination of the serum concentration of cardiac troponin I (cTnI). Myocardial specimens were obtained from the apex for microscopic examination and for determination of the levels of myocardial superoxide dismutase (SOD), malondialdehyde (MDA), and myeloperoxidase (MPO). Results Compared with group S, the serum cTnI concentrations, MDA content, and MPO activity were significantly increased, and the SOD activity was significantly decreased in I/R and CP groups (P<0.05). Compared with group I/R, the serum cTnI concentrations, MDA content, and MPO activity were significantly decreased, and the SOD activity was significantly increased in group CP (P<0.05). Myocardial injury was significantly attenuated in group CP as compared with group I/R. Conclusion Creatine phosphate can attenuate the myocardial injury induced by lung I/R in rats, and the mechanism is related to decrease in damage caused by lipid peroxidation. Key words: Phosphocreatine; Lung; Reperfusion injury