Editorial Oestrogen plays a permissive role in cardioprotection

This editorial refers to ‘Loss of ischaemic preconditioning in ovariectomized rat hearts: possible involvement of impairedprotein kinaseC ephosphorylation ’ byK. Shinmura et al.,1 pp. 387–394, this issue. Ischaemic preconditioning (IPC) is a powerful cardioprotec-tive intervention. It can salvage upwards of 75 % of the myocardium destined to otherwise infarct. This potent cardioprotective strategy has been observed in all animal species examined to date including mammals and birds.1 We have observed IPC’s protection in non-human primates (unpublished observation) and strong evidence exists of its efficacy in man.2,3 Since the initial description of IPC in 1986 by Murry et al.,4 many investigators have toiled to uncover its mechanism in the hopes of being able to apply the strategy clinically. As a result, much is now known con