Faculty Collaboration Database

Ex vivo reversal of heparin-mediated cardioprotection by heparinase after ischemia and reperfusion. J Pharmacol Exp Ther 1999 Sep;290(3):1041-7

Date

08/24/1999

Pubmed ID

10454476

Scopus ID

2-s2.0-0032813027 (requires institutional sign-in at Scopus site)   19 Citations

Abstract

Glycosaminoglycans, including heparin, have been demonstrated both in vitro and in vivo to protect the ischemic myocardium against reperfusion injury. In the present study, we sought to determine whether the cardioprotective effects of heparin administration could be reversed by the heparin-degrading enzyme heparinase. New Zealand white rabbits were pretreated with heparin (300 U/kg i.v.) or vehicle (saline). Two hours after treatment, hearts were removed, perfused on a Langendorff apparatus, and subjected to 25 min of global ischemia, followed by 45 min of reperfusion. Hemodynamic variables were obtained before ischemia (baseline) and every 10 min throughout the reperfusion period. Compared with vehicle-treated rabbits, the left ventricular end-diastolic and left ventricular developed pressures were improved significantly (p <.05) in the heparin-treated group. Ex vivo administration of heparinase (5 U/ml) immediately before the onset of global ischemia was associated with a reversal of the heparin-mediated cardioprotection. The uptake of a radiolabeled antibody to the intracellular protein myosin and creatine kinase release were used to determine membrane integrity and discriminate between viable and nonviable myocardial tissue. The uptake of radiolabeled antimyosin antibody and release of creatine kinase after reperfusion were increased in heparin-pretreated hearts exposed to heparinase, indicating a loss of membrane integrity and increased myocyte injury. These results demonstrate that neutralization of heparin by heparinase promotes increased myocardial injury after reperfusion of the ischemic myocardium.

Author List

Kilgore KS, Tanhehco EJ, Naylor KB, Lucchesi BR

Author

Elaine J. Tanhehco MD, PhD Assistant Professor in the Radiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Anticoagulants
Creatine Kinase
Heparin
Heparin Antagonists
Heparin Lyase
In Vitro Techniques
Iodine Radioisotopes
Lanthanum
Male
Myocardial Contraction
Myocardial Ischemia
Myocardial Reperfusion Injury
Myocardium
Rabbits