Combined local ischemic postconditioning and remote perconditioning recapitulate cardioprotective effects of local ischemic preconditioning

Am J Physiol Heart Circ Physiol. 2010 Jun;298(6):H1819-31. doi: 10.1152/ajpheart.01102.2009. Epub 2010 Mar 5.

Abstract

Ischemic postconditioning (PostC) and perconditioning (PerC) provide practical methods for protecting the heart against ischemia-reperfusion (I/R) injury, but their combined effects have not been studied in detail. Using an in vivo rat I/R model, we tested 1) whether additive effects were produced when local PostC was preceded by varying doses of remote PerC, and whether the optimal PostC+PerC regime is additive to local ischemic preconditioning (IPC), and 2) how combined PostC+PerC alters the activity of the reperfusion injury salvage kinase pathway. The optimal combination of PerC and PostC therapy was produced by PerC delivered with four cycles of 5 min of limb ischemia followed by 5-min reperfusion. This resulted in lower infarct size (22.56 +/- 4.45%) compared with rats with PostC alone (29.39 +/- 3.66%) and PerC alone (33.49 +/- 5.81%) and complementary differences in the generation of reactive oxygen species and apoptotic signaling. However, this optimal combination of PostC+PerC resulted in protection similar to local IPC alone (18.8 +/- 2.54%, P = 0.13), and when added to IPC there was no additional protection (19.62 +/- 2.89%, P = 0.675). Akt and ERK1/2 phosphorylation was induced by PostC and PerC and maximally by combined PostC+PerC treatment, and protection was abolished by phosphatidylinositol 3-kinase or ERK1/2 inhibitors. This study shows that neither PostC nor a maximized "dose" of PerC leads to optimal kinase signaling or cardioprotection compared with IPC alone. However, combined PostC+PerC may result in complementary effects on kinase signaling to recapitulate the effects of local IPC. Finally, combined PostC+PerC is not additive to IPC, suggesting that each works via a common pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Ischemic Preconditioning, Myocardial*
  • Male
  • Malondialdehyde / metabolism
  • Models, Animal
  • Myocardial Reperfusion Injury / metabolism
  • Myocardial Reperfusion Injury / physiopathology*
  • Myocardial Reperfusion Injury / prevention & control*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Reactive Oxygen Species / metabolism
  • Signal Transduction / physiology
  • Superoxides / metabolism

Substances

  • Reactive Oxygen Species
  • Superoxides
  • Malondialdehyde
  • Proto-Oncogene Proteins c-akt
  • Extracellular Signal-Regulated MAP Kinases