High-energy phosphates and function in isolated, working rabbit hearts

Autor: M. D. Devous, Edward D. Lewandowski, R. I. Nunnally
Rok vydání: 1987
Předmět:
Zdroj: American Journal of Physiology-Heart and Circulatory Physiology. 253:H1215-H1223
ISSN: 1522-1539
0363-6135
DOI: 10.1152/ajpheart.1987.253.5.h1215
Popis: 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 responses 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 degrees 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.
Databáze: OpenAIRE