FLUORIMETRIC STUDIES OF EPINEPHRINE AND ARTERENOL

Abstract

Spectrographic studies demonstrate that the fluorescence produced by epinephrine in alkaline soln. has a maximum at 5,400 A. The fluorescence of a comparable 1-arterenol soln. is 10 times weaker than that of epinephrine and slightly more toward the violet. Bifluorescence, a complication of irradiation of plasma, is reduced both by the use of monochromatic incident light and selective filters. The great decrease in light transmission caused by highly selective filter arrangements is compensated for by a photomultiplier-amplifier combination. Estimation of the reaction rate constants of formation of the fluorescent substance from epinephrine and of its destruction indicates that the latter reaction is faster than the former. Evidence is presented from the study of the reaction rates that there must be at least a 2-step oxidation reaction of the formation of the fluorescent substance from epinephrine. Spectrographic studies show the identity of the fluorescence produced anaerobically from aHrenochrome with that produced aerobically from epinephrine, and support the possibility that adrenochrome may be an intermediate stage in the production of the fluorescent substance. Strong alkalinity and the presence of oxygen are 2 recognized conditions for the formation of the unknown fluorescent substance from epinephrine. If oxygen is in excess the fluorescent substance is rapidly destroyed.