This study investigated if exogenous adenosine (ADO) improves recovery of cardiac function during repetfusion (RPF) after global ischemia (ISC), and if lidocaine is required for. ADO-mediated cardioprotection during reperfusion. Isolated rabbit hearts, retrogradely perfused with erythrocyte-enriched Krebs-Henseleit buffer at constant left ventricular (LV) volume and physiologic flow rates, were subjected to 20 min. of global no-flow ischemia, and reperfused at the same rate as before ischemia. Hearts received one of the following treatments: 1) control (CON; no drug treatment), 2) adenosine (ADO; 200J.1M before and after ISC), or 3) adenosine+lidocaine (NL; 200 JlM ADO before and after ISC, 1 J.Lg/ml/min LIDO during first 20 min. of RPF). Myocardial function (e.g., using developed LV pressure, DP) declined as expected during no-flow ischemia and gradually returned during reperfusion. Functional recovery in ADO and NL groups were significantly improved from CON during early RPF (p<0.05 at 2 min RPF), but not at later RPF times(> 10 min). Differences did not exist between ADO and NL groups at any RPF time except at 10 min. RPF. Additionally, myocardial ATP content was measured before ischemia, after ischemia, and after 10 and 30 min of reperfusion. ATP content decreased significantly during ischemia; ADO hearts showed a increased repletion (85% of pre-ischemia level) of ATP at 30 min. of reperfusionas compared to CON (60%). These data suggest that ADO alone improves cardiac functional recovery during early repetfusion; LIDO does not appear to be required for ADO-mediated cardioprotection. ADO and LIDO do not improve cardiac function, however, ADO appears to improve myocardial ATP repletion at later RPF times in this blood-perfused rabbit model of global myocardial ISC/RPF.
| Identifer | oai:union.ndltd.org:pacific.edu/oai:scholarlycommons.pacific.edu:uop_etds-3259 |
| Date | 01 January 1994 |
| Creators | Vos, Lynette C. |
| Publisher | Scholarly Commons |
| Source Sets | University of the Pacific |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | University of the Pacific Theses and Dissertations |
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