Serine-threonine protein kinase Akt does not mediate ischemic tolerance after global ischemia in the gerbil

The protein kinase Akt/PKB has been implicated in antiapoptosis and neurona l survival. The authors now show that Akt is phosphorylated in the hippocam pus during the early reperfusion period after 3.5 minutes bilateral carotid artery occlusion (BCAO) in the gerbil. Repeated sublethal ischemia induces ischemic tolerance, which is known as ischemic preconditioning. Ischemic p reconditioning does not affect the amount of Akt protein, but rather decrea ses the phosphorylation of Akt at Ser-473 after 10 minutes reperfusion afte r 3.5 minutes BCAO. These results suggest that although Akt may play a role in neuronal survival after ischemia, it may not play a role in isehemic to lerance by preconditioning.