Ischemic Preconditioning with Co-infusion of Adenosine and Norepinephrine

Objective To evaluate the cardiac protective effect of co-infusion of adenosine and norepinephrine. Methods Twenty-five New Zealand white rabbits were randomly divided into 5 groups. Ischemia preconditioning or drug infusion mimicking ischemia preconditioning was first carried out for 5min, then reperfusion for 10min, regional ischemia again for 30min, and subsequently reperfusion for 3h. HR and BP were monitored during the experiments. Serum CK and MDA were determined before ischemic or drug preconditioning (baseline) and 3h after reperfusion. Results Basal serum CK and MDA were comparable in all groups. Serum CK and MDA in all preconditioning groups were significantly lower than that in the control group after 3h of reperfusion (P0.05). Difference was not significant among the preconditioning groups. Blood pressure was found lowered significantly during adenosine infusion; intravenous norepinephrine infusion significantly caused elevation of mean arterial blood pressure; but co-infusion of adenosine and norepinephrine caused no significant change. Conclusion Co-infusion of adenosine and norepinephrine seems able to precondition the heart without any significant hemodynamic change.