Concurrent Plasma Epinephrine, Norepinephrine and 17-Hydroxycorticosteroid Levels During Conditioned Emotional Disturbances in Monkeys

Abstract
In studies involving biochemical measurements of plasma 17-OH-CS, norepinephrine, and epinephrine levels during conditioned emotional disturbances in monkeys, elevations in 17-OH-CS and norepinephrine levels were observed in a variety of experimental situations. The regulation of epinephrine secretion, however, appeared to have a more selective basis. In relatively stereotyped, predictable situations such as avoidance and CER, patterns of 17-OH-CS and norepinephrine elevation, with little or no change in plasma epinephrine levels, were observed. In first-experience situations and rather complicated multiple-schedule conditioning procedures, patterns of marked 17-OH-CS, norepinephrine, and epinephrine elevations were observed. These experiments suggest that several interacting elements may be necessary for marked epinephrine release during anticipatory responses. An effort has been made to identify some of these elements in terms of both environmental and biological factors that appear to be common to those situations in which marked epinephrine elevations were observed. The element of uncertainty or unpredictability, in combination with such factors as the threat of a noxious stimulus and the anticipation of coping activity, may be a particularly critical factor in the determination of epinephrine release during emotional disturbances.