Federico Bizzarri

Myocardial ischemic injury and purine metabolism in patients undergoing coronary artery bypass.

OBJECTIVESnHigh-energy phosphates and their catabolic products were determined in myocardium during coronary artery bypass surgery with blood cardioplegic reperfusion in order to evaluate the effects of aortic cross-clamping and reoxygenation on myocardial purine metabolism.nnnDESIGN AND METHODSnTransmural left ventricular biopsy specimens were taken with ITu-Cut biopsy needles, before aortic cross-clamping, before cross-clamp removal and after 30 of reperfusion; perchloric extracts of the material were analyzed for nucleotide content by capillary zone electrophoresis (CZE). The CZE procedure used separates the complete spectrum of purine metabolites in myocardial extracts obtained from 0.6-8.6 mg biopsy material.nnnRESULTSnThe basal values of ATP/ADP ratio and energy charge were low, IMP content was high. After the ischemic period, ATP levels further decreased and IMP, nucleosides and bases accumulated. After reperfusion, nucleoside and base basal levels, but not energy charge, were restored to some extent.nnnCONCLUSIONSnThe study arises the problem of myocardial preservation during heart surgery. In this investigation, capillary electrophoresis was an extremely adaptable technique for the evaluation of ischemic injury and could be useful in studying the effects of cardioplegic solutions.