EFFECTS OF ADENOSINE INFUSION WITH OR WITHOUT LEUKOCYTE DEPLETION ON RECOVERY AFTER HYPOTHERMIC ISCHEMIA IN NEONATAL LAMB HEARTS

Objective: Leukocytes have been shown to have an important role in isc hemia/reperfusion injury. Adenosine also reduced this ischemia/ reperf usion injury. There is an interaction between adenosine and leukocyte via receptor mediated function. To determine whether beneficial effect s of adenosine on reperfusion injury is mediated by changes in leukocy te function, we studied the effects of adenosine with and without leuk ocyte depletion during reperfusion on the functional recovery of the n eonatal myocardium after cold cardioplegic arrest. Materials and metho ds: We infused adenosine (350 mu mol/l) during the first 20 min of rep erfusion for adenosine treated group and adenosine-leukocyte treated g roup. The other two groups were perfused with leukocyte treated blood or untreated blood. All the groups were subjected to 2 h of cold cardi oplegic ischemia (n = 8 in each group). At 30 min of reperfusion, LV f unction was measured. Coronary blood flow and oxygen consumption (MVO2 ) were also measured to evaluate the metabolic recovery. Results: Aden osine treated, adenosine-leukocyte treated, and leukocyte treated grou ps showed better functional recovery than the control group (maximum d eveloped pressure: control = 74.6 +/- 5.6%, adenosine treated = 97.6 /- 9.5%, adenosine-leukocyte treated = 98.5 +/- 5.6%, leukocyte treate d = 82.5 +/- 6.0%, P < 0.05). Both adenosine treated and adenosine-leu kocyte treated groups showed better recovery than leukocyte treated gr oup (P < 0.05). Coronary blood flow was higher in adenosine-leukocyte treated group compared to other groups (P < 0.05). MVO2/beat was highe r in adenosine treated, adenosine-leukocyte treated, and leukocyte tre ated groups than control group (P < 0.05), Conclusion: Adenosine, with or without leukocyte depletion, had similar beneficial effect on reco very of systolic and diastolic functions, which involved other mechani sms in addition to the leukocyte inhibitory effect. (C) 1998 Elsevier Science B.V. All rights reserved.