Abstract
1. The contents of norepinephrine, epinephrine, dopamine, and dopa were determined in various portions of the heart in 6 intact dogs. Catecholamines were separated with aluminum hydroxide and cation exchange resin using Duolite C-25. Norepinephrine, epinephrine, and dopa were determined fluorimetrically by the modified method of EULER and FOLDlNG and dopamine was by the method of WEIL-MALHERBE and BONE. 2. Although epinephrine, dopamine, and dopa were distributed almost equally throughout the heart, the norepinephrine concentration was significantly higher in the atria than in the ventricles.
