| Abstract: | The presence of cocarboxylase (CC) is essential for the oxidation of pyruvate to acetylcoenzyme A (acetyl-CoA) and its subsequent degradation by means of the Krebs cycle. We compared the effects of various concentrations of CC in a cardioplegic solution on the survival and hemodynamic and metabolic recovery of 23 isolated, working rat hearts subjected to 60 minutes of hypothermic (23 degrees C) ischemic arrest. Group 1 (N = 6) consisted of hearts infused with the basic cardioplegic solution (Tyers' solution with glucose), to which no CC was added. In group 2 (N = 6) CC was added at 0.1 ml/L to the cardioplegic solution. In group 3 (N = 5) CC was added at 1 ml/L, and in group 4 (N = 6) CC was added at 10 ml/L. The cardioplegic infusions were performed at a pressure of 40 mm Hg for 2 minutes just before arrest; 30 minutes later they were performed again for 1 minute. Only two hearts (33.3%) recovered in group 1 whereas five recovered in group 2, five (100%) in group 3, and five (83.3%) in group 4. The recovery of hemodynamic performance as a percentage of preischemic control values showed marked improvement in the CC groups, especially group 3, when compared with group 1. The metabolic variables in the CC groups were also markedly improved, with significantly (p less than .05) decreased levels of tissue lactate and increased levels of creatine phosphate compared with those in group 1.(ABSTRACT TRUNCATED AT 250 WORDS) |
