Plasma Cyclic AMP and Total Catecholamines during Acute Myocardial Infarction in Man

There is marked alteration in endocrine activity during acute myocardial infarction (AMI). Many of the hormones involved act by changing target cell concentrations of adenosine 3′: 5′ monophosphate (cyclic AMP). Since cyclic AMP can escape from cells, changes in intracellular concentrations of the nucleotide may be reflected in changes in plasma levels. The purpose of this study was to determine whether plasma cyclic AMP concentrations alter during the development of AMI.–Elevation of plasma cyclic AMP concentrations was noted during the first few hours following the onset of symptoms of AMI. The highest concentrations, recorded in a group of four patients with shock, showed a range of 54–193 pmol/ml which was significantly elevated compared to the normal range of 9–22 pmol/ml. This increase in plasma cyclic AMP correlated significantly and positively with plasma concentrations of total catecholamines. Patients with the worst prognosis had the highest plasma concentrations of cyclic AMP and total catecholamines.