Protein Kinase C BetaII Peptide Inhibitor Exerts Cardioprotective Effects in Rat Cardiac Ischemia/Reperfusion Injury

Document Type

Article

Publication Date

8-1-2005

Abstract

Ischemia followed by reperfusion (I/R) in the presence of polymorphonuclear leukocytes (PMNs) results in a marked cardiac contractile dysfunction. A cell-permeable protein kinase C (PKC) betaII peptide inhibitor was used to test the hypothesis that PKC betaII inhibition could attenuate PMN-induced cardiac dysfunction by suppression of superoxide production from PMNs and increase NO release from vascular endothelium. The effects of the PKC betaII peptide inhibitor were examined in isolated ischemic (20 min) and reperfused (45 min) rat hearts with PMNs. The PKC betaII inhibitor (10 microM; n = 7) significantly attenuated PMN-induced cardiac dysfunction compared with I/R hearts (n = 9) receiving PMNs alone in left ventricular developed pressure (LVDP) and the maximal rate of LVDP (+dP/dt(max)) cardiac function indices (p < 0.01). The PKC betaII inhibitor at 10 microM significantly increased endothelial NO release from a basal value of 1.85 +/- 0.18 pmol NO/mg tissue to 3.49 +/- 0.62 pmol NO/mg tissue from rat aorta. It also significantly inhibited superoxide release (i.e., absorbance) from N-formyl-L-methionyl-L-leucyl-L-phenylalanine-stimulated rat PMNs from 0.13 +/- 0.01 to 0.02 +/- 0.004 (p < 0.01) at 10 microM. Histological analysis of the left ventricle of representative rat hearts from each group showed that the PKC betaII peptide inhibitor-treated hearts experienced a marked reduction in PMN vascular adherence and infiltration into the postreperfused cardiac tissue compared with I/R + PMN hearts (p < 0.01). These results suggest that the PKC betaII peptide inhibitor attenuates PMN-induced post-I/R cardiac contractile dysfunction by increasing endothelial NO release and by inhibiting superoxide release from PMNs.

Publication Title

The Journal of Pharmacology and Experimental Therapeutics

Volume

314

Issue

2

First Page

542

Last Page

551

PubMed ID

15878997

Comments

This article was published in Journal of Pharmacology & Experimental Therapeutics, Volume 314, Issue 2, August 2005, Pages 542-51.

The published version is available at http://dx.doi.org/10.1124/jpet.104.082131

Copyright © 2005 by the American Society for Pharmacology and Experimental Therapeutics

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