Abstract
A high-velocity continuous flow apparatus permitted EPR (electron paramagnetic resonance) spectroscopy of the labile free radicals formed in solution by inorganic redox agents from a number of hormone molecules and their congeners. In this report the existence of hormonal free radicals was confirmed for catechola-mine hormones (epinephrine, norepinephrine) and adrenochrome. A concluding part of this communication will present similar data regarding iodothyronines, indole hormones (serotonin, indole acetic, and butyric acids), estrogens (steroids and nonsteroidal synthetics), and 1 protein hormone (insulin).