An isolated, working, rabbit heart has been developed for use with nuclear magnetic resonance (NMR) spectroscopy. This model is functionally stable over a 4-h period and displays classic hemodynamic reponses to work-load changes. Control 31P spectra of this preparation (n = 5) were obtained with simultaneous recordings of left ventricular pressure (LVP), LVP differentiated with respect to time (dP/dt), heart rate (HR), and cardiac output (CO), ATP, phosphocreatine (PCr), and hemodynamics remained stable over a 90-min perfusion. Hearts were also subjected to 13.5 min of global ischemia (IS) at 37°C followed by 60 min of reperfusion (RE, n = 7) or 45 min of chronic IS (n = 6). Contraction ceased within 60 s of IS. PCr loss was rapid, reaching undetectable limits by 11 min. ATP loss was gradual and bore no relationship to functional loss. ATP fell to 60 ± 4% (means ± SE) of pre-IS levels after 13.5 min of IS. With RE, PCr returned to control levels, whereas ATP values remained depressed for the entire 60 min. Functional activity resumed with RE, but dP/dt did not rise above 85 ± 7% of preischemic values. No correlation between residual ATP at the end of IS and functional recovery during RE was evident.
|Original language||English (US)|
|Journal||American Journal of Physiology - Heart and Circulatory Physiology|
|State||Published - Dec 1 1987|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)