British journal of anaesthesia
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Ischaemic preconditioning can protect the myocardium against ischaemic injury by opening of the adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channel. Isoflurane is also thought to open this channel. The present investigation tested the hypothesis that pre-ischaemic treatment with isoflurane mimics ischaemic preconditioning (producing chemical preconditioning) and thereby protects the myocardium against ischaemic injury in an isolated rat heart model. ⋯ Recovery of LV developed pressure was improved after ischaemic preconditioning [after 60 min reperfusion, mean 63 (SEM 6)% of baseline] compared with the control group [18 (4)% P<0.01] but not by isoflurane, independently of concentration or duration of administration [ISO-1, 17 (2)%, P=0.99 vs control; ISO-2, 12 (3)%, P=0.64; ISO-3, 4 (1)%, P=0.06]. Total creatine kinase release over 1 h of reperfusion was not significantly different between control [251 (36) U g(-1) dry weight] and all isoflurane groups [ISO-1, 346 (24) U g(-1), P=0.30; ISO-2, 313 (33) U g(-1), P=0.73; ISO-3, 407 (40) U g(-1), P=0.03]. These results indicate that pre-ischaemic administration of isoflurane does not cause anaesthetic-induced preconditioning in the isolated rat heart.