From rapid to delayed and remote postconditioning: the evolving concept of ischemic postconditioning in brain ischemia.
Ischemic postconditioning is a concept originally defined to contrast with that of ischemic preconditioning. While both preconditioning and postconditioning confer a neuroprotective effect on brain ischemia, preconditioning is a sublethal insult performed in advance of brain ischemia, and postconditioning, which conventionally refers to a series of brief occlusions and reperfusions of the blood vessels, is conducted after ischemia/reperfusion. In this article, we first briefly review the history of preconditioning, including the experimentation that initially uncovered its neuroprotective effects and later revealed its underlying mechanisms-of-action. We then discuss how preconditioning research evolved into that of postconditioning--a concept that now represents a broad range of stimuli or triggers, including delayed postconditioning, pharmacological postconditioning, remote postconditioning--and its underlying protective mechanisms involving the Akt, MAPK, PKC and K(ATP) channel cell-signaling pathways. Because the concept of postconditioning is so closely associated with that of preconditioning, and both share some common protective mechanisms, we also discuss whether a combination of preconditioning and postconditioning offers greater protection than preconditioning or postconditioning alone.
Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305-5327, USA. hzhao@stanford.edu
Heng
H
Zhao
Chuancheng
C
Ren
Xingmiao
X
Chen
Jiangang
J
Shen
D000818:Animals; D001921:Brain / Q000098:blood supply*; D002545:Brain Ischemia / Q000378:metabolism* / Q000628:therapy*; D006801:Humans; D057775:Ischemic Postconditioning / Q000379:methods*; D019194:Ischemic Preconditioning / Q000379:methods*; D018696:Neuroprotective Agents / Q000627:therapeutic use*
D018696:Neuroprotective Agents