Anaesthetic preconditioning but not postconditioning prevents early activation of the deleterious cardiac remodelling programme: evidence of opposing genomic responses in cardioprotection by pre- and postconditioning

Background. Anaesthetic preconditioning (A_PreC) and postconditioning (A_PostC) both provide protection against ischaemia–reperfusion in the heart. However, post-ischaemic gene responses may differ between the two therapeutic strategies. Methods. Isolated perfused rat hearts were exposed to 40 min test ischaemia followed by 3 h reperfusion and used to determine transcriptional changes in response to A_PreC and A_PostC. A_PreC was induced by 15 min of isoflurane 2.1 vol% followed by 10 min of washout, and A_PostC was induced by 15 min of isoflurane 2.1 vol% administered at the onset of reperfusion. Untreated hearts served as ischaemic control (ISCH). Coupled-two way clustering (CTWC) and principal component analysis (PCA) were used to identify gene expression patterns. Results. A_PreC (7[sd 1]%) and A_PostC (6[2]%) produced a similar decrease in infarct size (ISCH 36[1]%, P