Norepinephrine, Epinephrine, and Dopamine Contents of the Cardiovascular System in Long-term Diabetics

Norepinephrine, epinephrine, and dopamine concentrations were studied in the cardiovscular system of postmortem material obtained from six long-term diabetics and six control subjects. Norepinephrine concentration was considerably reduced in the cardiovascular system of the diabetic patients. The mean norepinephrine concentration in the apex of the heart, the radial artery, the posterior tibial artery, and the femoral artery in the diabetics averaged 6, 9, 12, and 20 per cent, respectively, of the corresponding mean values in the controls. Epinephrine was present in the cardiovascular system in the controls but in small amounts in comparision with norepinephrine. There was no correlation between the epinephrine and the norepinephrine concentrations in the tissue. In the diabetics the epinephrine concentration in the heart and in the arteries did not differ from the values obtained in the controls. The dopamine concentration averaged 11 per cent of the norepinephrine concentration in the cardiovascular system in the controls. There was a strong correlation between tissue concentrations of dopamine and of norepinephrine. In the diabetics the dopamine concentration was reduced, but relatively less than that of norepinephrine, and constituted 53 per cent of the norepinephrine concentration. It is suggested that the depletion of the norepinephrine stores in the heart in diabetic patients may in part be responsible for their reduced survival rate in acute myocardial infarction.