Heart "Sympathin"

In view of the growing recognition of the pathogenic role of the adrenosympathetic humoral neurotransmitters in the heart muscle as chemical anoxia-producing agents, cardiac "sympathin" was extracted and assayed both colorimetrically and biologically, and some of its chemical and pharmacodynamic properties were studied in detail. It proved to be at least in part identical with nor-epinephrine (arterenol) and to exert effects analogous to those of epinephrine and nor-epinephrine upon blood pressure, heart rate and the electrocardiogram (depression or inversion of the T wave). Its action was intensified by cocaine and counteracted by nitroglycerine.