AJP - Regulatory, Integrative and Comparative Physiology, Vol 237, Issue 5 327-R333, Copyright © 1979 by American Physiological Society
Metabolism of totally ischemic excised dog heart. II. Interpretation of a computer model
D. Garfinkel and M. J. Achs
Analysis of the ischemic dog heart preparation described in the preceding
paper indicates that it is an analogue in slow motion of the tissue in the
center of a cardiac infarct. It is respiring very slowly and not capable of
performing mechanical work. Glycolysis starts up with both glucose and
glycogen as inputs. Later hexokinase and to some extent phosphofructokinase
become limiting owing to inhibitor accumulation or acidosis. Metabolism
then results primarily from cAMP-driven glycogenolysis, largely limited by
the glycogen debranching enzymes at later times, with accumultion not only
of lactate and alpha-glycerophosphate but of glucose as well. Amino acid
levels oscillate with time while fatty acids accumulate at late times. The
elevation of cAMP at later times may involve disturbances in its metabolism
as well as mechanisms such as adenosine accumulation that are more
important in cardiac ischemia than in normal heart. The clinical
implications of this behavior are discussed.
