J Korean Med Sci.  2003 Jun;18(3):337-343. 10.3346/jkms.2003.18.3.337.

Infarct Size-limiting Effect of Calcium Preconditioning in Rabbit Hearts

• Kim HD

• KMID: 2157647
• DOI: http://doi.org/10.3346/jkms.2003.18.3.337

Abstract

Recent studies demonstrated that brief period of Ca2+ depletion and repletion (Ca2+ preconditioning, CPC) has strong protective effects against ischemia in a rat heart. CPC and classic preconditioning (IPC) were compared in relation with infarct size and protein kinase C (PKC) isozymes. Isolated Langendorff-perfused rabbit hearts were subjected to 45-min ischemia (Isc) followed by 120-min reperfusion (R) with or without IPC, induced by 5-min Isc and 10-min R. In the CPC hearts, 5-min Ca2+ depletion and 10-min repletion (CPC) were given before 45-min Isc, with or without concurrent PKC inhibition (calphostin C, 200 nmol/L). IPC enhanced recovery of LV function, while CPC did not. Infarct size was significantly reduced by both CPC and IPC (p < 0.05 vs. ischemic control). Membrane PKC was significantly increased from 2.53 +/- 0.07 (baseline, nmol/g tissue) to 3.11+/-0.07, 3.34 +/- 0.11, 3.15 +/- 0.09, and 3.06 +/- 0.08 by IPC, IPC and 45-min Isc, CPC and 45-min Isc, respectively (p < 0.01). Immunoblots of membrane PKC were increased by IPC, IPC and 45-min Isc, and CPC. These effects were abolished by PKC inhibition. Thus, activation of PKC may have trigger role in the mechanism of cardioprotective effect by CPC.

Keyword

Ischemic Preconditioning Myocardial; Myocardial Infarction; Reperfusion Injury; Protein Kinase C; Rabbits; Heart

MeSH Terms

Animals
Calcium/*pharmacology
Cardiotonic Agents/*pharmacology
In Vitro
*Ischemic Preconditioning, Myocardial
Isoenzymes/metabolism
L-Lactate Dehydrogenase/metabolism
Male
Myocardial Infarction/*pathology
Myocardium/enzymology/pathology
Protein Kinase C/metabolism
Rabbits