Energy formation processes in the myocardium during measured limitation of coronary blood flow

: Effect of short-term partial limitation of coronary circulation (by 30%, 50% and 70%) on energy formation in myocardium was studied in animals with closed thorax after catheterization and autoperfusion of the circumflex branch of left coronary artery. Distinct alterations in energy metabolism were observed already after a decrease of the coronary circulation by 30%. Several enzymes were inhibited in tricarboxylic acid cycle and in respiratory chain following development of ischemia. Despite of the inhibition of the aerobic oxidation content of ATP and glycogen maintained rather stable. Content of ATP was decreased down to 60% of the initial level only after limitation of the circulation by 2/3. Deficiency in aerobic energy production as well as maintaining of a rather stable content of ATP and glycogen were apparently compensated by an increase in cAMP content, activation of glycolysis and pentose phosphate pathway and of adenosine formation.