Effects of halothane and enflurane on myocardial metabolism during postischaemic reperfusion in the rat

In experiments on isolated rat heart-lung preparation, the effects of halothane and enflurane on myocardial metabolism during postischaemic reperfusion were evaluated with intramyocardial high energy phosphates, lactate and glycogen. Hearts were perfused for 10 min initially and made globally ischaemic for 8 min. Afterwards, they were reperfused for 12 min. Halothane or enflurane was administered from 5 min after the start of perfusion to the end of reperfusion. There were no significant differences in contents of high energy phosphates between control (C), halothane (H) and enflurane (E) groups (ATP: 15.50 +/- 0.87, 16.05 +/- 1.99 and 15.16 +/- 2.03 mumol/g dry wt, respectively). However, lactate levels in the hearts in Groups H and E were significantly higher than those in Group C (44.04 +/- 10.54, 40.63 +/- 10.34 vs 28.63 +/- 5.98). Slight deterioration in the myocardial oxidation-reduction state may be caused by inhalational anaesthetics when they are administered during the postischaemic reperfusion period.