Interact CardioVasc Thorac Surg 2009;9:20-25. doi:10.1510/icvts.2008.191916 © 2009 European Association of Cardio-Thoracic Surgery
Institutional report - Experimental |
Single high-dose intramyocardial administration of erythropoietin promotes early intracardiac proliferation, proves safety and restores cardiac performance after myocardial infarction in rats
Ralf Gäbel1,
Christian Klopsch1,
Dario Furlani1,
Can Yerebakan,
Wenzhong Li,
Murat Ugurlucan,
Nan Ma* and
Gustav Steinhoff
Department of Cardiac Surgery, University of Rostock, Germany
*Corresponding author. Biomedizinischen Forschungszentrum (BMFZ). Schillingallee 69, Rostock 18057, Germany. Tel.: +49 381 494 61 00; fax: +49 381 494 61 02.
E-mail address: nan.ma{at}med.uni-rostock.de (N. Ma).
Various studies demonstrate erythropoietin (EPO) as a cardioprotective growth hormone. Recent findings reveal EPO in addition might induce proliferation cascades inside myocardium. We aimed to evaluate whether a single high-dose intramyocardial EPO administration safely elevates early intracardiac cell proliferation after myocardial infarction (MI). Following permanent MI in rats EPO (3000 U/kg) in MI EPO-treatment group (n=99) or saline in MI control group (n=95) was injected along the infarction border. Intramyocardial EPO injection activated the genes of cyclin D1 and cell division cycle 2 kinase (cdc2) at 24 h after MI (n=6, P<0.05) evaluated by real time-PCR. The number of Ki-67+ intracardiac cells analyzed following immunohistochemistry was significantly enhanced by 45% in the peri-infarction zone at 48 h after EPO treatment (n=6, P<0.001). Capillary density was significantly enhanced by 17% as early as seven days (n=6, P<0.001). After six weeks, left ventricular performance assessed by conductance catheters was restored under baseline and dobutamine induced stress conditions (n=11–14, P<0.05). No thrombus formation was observed in the heart and in distant organs. No deleterious systemic adverse effects were apparent. Single high-dose intramyocardial EPO delivery proved safety and promoted early intracardiac cell proliferation, which might in part have contributed to an attenuated myocardial functional decline.
Key Words: Myocardial ischemia; Intracardiac proliferation; Cell cycle genes; Adverse effects; Angiogenesis
|
|