|Houston RJF et al.|
Adenosine added to cardioplegic solution at low dose reduces functional recovery after normothermic ischaemia in isolated rat heart
Journal of Clinical and Basic Cardiology 1999; 2 (1): 110-112
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Keywords: Adenosin, isoliertes Herz, Kardioplegie, adenosine, cardioplegia, working isolated rat heart
Adenosine and its analogues have emerged as promising candidates in the search for substances to improve functional recovery after intermittent cardioplegia, and the results of human trials are starting to be published, one study having demonstrated dose-dependent protective effects. Adenosine may improve recovery of high-energy phosphates, or mimic ischaemic preconditioning by stimulating adenosine A1 receptors. In a working, isolated rat heart model, hearts which received 50 micromol x L-1 adenosine in a warm ?blood? cardioplegic solution administered before and after a 10 minute normothermic ischaemic insult showed a lower post-ischaemic recovery of haemodynamic performance than control hearts, both immediately after resuming work (80 % (n = 5) compared with 92 % (n = 5), p = 0.014) and after 20 min (67 % against 88 % respectively, p = 0.042). After discussing a number of possible reasons for this unexpected result, including exacerbated reperfusion injury, temperature and species differences we suggest that adenosine should be adopted cautiously as an additive to cardioplegic solutions, and that delivery protocol and dosage should be very carefully designed and administered. J Clin Basic Cardiol 1999; 2: 110-12.