Hormones and Circadian Rhythm

Abstract

In the former part of this paper are given the general remarks over the studies on the circadian rhythms in hormones.Described in our papers were the circadian rhythms of oral temperature, the pituitary-adrenal cortical and the sympathetic-adrenal medullary systems, and their responses to the phase shift of waking and sleeping times. The papers included five subjects-patterns of excretion fornormal day work, patterns during and after experimental night shift, patterns during experimental irregular shift work, responses to different work loads in daytime and at night, andpatterns of three-shift workers.Reported from Levi's laboratory in Sweden were the circadian properties of the sympatheticadrenal medullary system and its responses to changes of activity phase.The paper is divided into four parts-patterns of excretion for normal day work, patternsduring continuous 24 hour activity, reactions in normal day workers suddenly exposed to a180° work phase shift, and finally patterns of experienced three-shift workers. The desynchronization of different variables were recognized with the synchronization among somevariables after the phase shift.A complete re-entrainement of circadian rhythms were not obserbed during the night shift.After the change back to day work re-entrainement seems to have occurred relatively quickly.