Cardiac preconditioning with 4-h, 17 degrees C ischemia reduces [Ca(2+)](i) load and damage in part via K(ATP) channel opening. Am J Physiol Heart Circ Physiol 2002 Jun;282(6):H1961-9
Date
05/11/2002Pubmed ID
12003799DOI
10.1152/ajpheart.01032.2001Scopus ID
2-s2.0-0036086138 (requires institutional sign-in at Scopus site) 22 CitationsAbstract
Brief ischemia before normothermic ischemia protects hearts against reperfusion injury (ischemic preconditioning, IPC), but it is unclear whether it protects against long-term moderate hypothermic ischemia. We explored in isolated guinea pig hearts 1) the influence of two 2-min periods of normothermic ischemia before 4 h, 17 degrees C hypothermic ischemia on cardiac cytosolic [Ca(2+)], mechanical and metabolic function, and infarct size, and 2) the potential role of K(ATP) channels in eliciting cardioprotection. We found that IPC before 4 h moderate hypothermia improved myocardial perfusion, contractility, and relaxation during normothermic reperfusion. Protection was associated with markedly reduced diastolic [Ca(2+)] loading throughout both hypothermic storage and reperfusion. Global infarct size was markedly reduced from 36 +/- 2 (SE)% to 15 +/- 1% with IPC. Bracketing ischemic pulses with 200 microM 5-hydroxydecanoic acid or 10 microM glibenclamide increased infarct size to 28 +/- 3% and 26 +/- 4%, respectively. These results suggest that brief ischemia before long-term hypothermic storage adds to the cardioprotective effects of hypothermia and that this is associated with decreased cytosolic [Ca(2+)] loading and enhanced ATP-sensitive K channel opening.
Author List
Chen Q, Camara AK, An J, Riess ML, Novalija E, Stowe DFAuthors
Amadou K. Camara PhD Professor in the Anesthesiology department at Medical College of WisconsinDavid F. Stowe MD, PhD Professor in the Anesthesiology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
Adenosine TriphosphateAnimals
Calcium
Cold Temperature
Cytosol
Female
Guinea Pigs
Heart
Hypothermia, Induced
Ion Channel Gating
Ischemic Preconditioning, Myocardial
Kinetics
Male
Myocardial Contraction
Myocardial Reperfusion Injury
Potassium Channels