AJP - Heart and Circulatory Physiology, Vol 232, Issue 4 394-H399, Copyright © 1977 by American Physiological Society
Computer simulation of ischemic rat heart purine metabolism. II. Model behavior
M. C. Kohn and D. Garfinkel
The behavior of a model for the partial depletion of adenine nucleotides in
the perfused rat heart has been compared for ischemic and high coronary
flow anoxic conditions. The accumulation of noradrenaline in the
interstitial fluid greatly activates adenylate cyclase ultimately resulting
in the degradation of 11.02 micronmol/g dry wt of ATP to adenosine,
inosine, and hypoxanthine in 30 min. The high coronary flow rate during
anoxic perfusion promotes washout of the noradrenaline from the
interstitial fluid so that the hormone accumulates to only one fifth of its
highest level in ischemia. This results in only slight activation of
adenylate cyclase and in insignificant degradation of ATP in 2 min. The
behavior of the model has been examined for two aerobic conditions--a
transition from light to heavy work (2 min) and a transition from
substrate-free to glucose perfusion (12 min), In both cases adenylate
cyclase was not activated above its basal activity, and insignificant
depletion of adenine nucleotides is predicted by the model.
