Changes in the intracellular concentration of glutamate and aspartate in hearts of patients undergoing coronary artery surgery. Suleiman, M. S., W. C. Dihmis, M. Caputo, G. D. Angelini & A. J. Bryan. Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, Bristol BS2 8HW, U.K.
APStracts 3:0466H, 1996.
Myocardial ischaemic arrest, using a cold crystalloid cardioplegic solution, decreases intracellular concentrations ([mu]mol/g wet weight ) of glutamate (from 6.2+/-0.5 to 4.5+/-0.45, n=19, P<0.05) ATP (from 3.0+/-0.4 to 1.9+/-0.3, n=9, P<0.05) but not aspartate. After 20 min of normothermic reperfusion the fall in ATP and glutamate was maintained (4.5+/-0.52 and 2.0+/-0.2 for glutamate and ATP, respectively) and there was a fall in aspartate (from 1.32+/-0.12 to 0.9+/-0.1). Myocardial arrest with cold blood cardioplegic solution did not cause a significant fall in tissue ATP, glutamate or aspartate. However, on reperfusion all three fell significantly. With the exception of a fall in tissue valine during ischaemia with cold crystalloid cardioplegic solution and a rise in alanine during ischaemia with cold blood cardioplegic solution, there were no significant changes in tissue alanine, valine, leucine or isoleucine during ischaemia or on reperfusion using crystalloid or blood cardioplegic solutions. This work documents the changes in the intracellular concentrations of important metabolites in the hearts of patients undergoing coronary artery surgery using different myocardial protection techniques.

Received 15 May 1996; accepted in final form 16 September 1996.
APS Manuscript Number H440-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 November 1996