The diurnal rhythm of adrenaline secretion in subjects with different working habits.

Patkai, P. The diurnal rhythm of adrenaline secretion in subjects with different working habits. Acta physiol. scand. 1971. 81. 30–34. Subjects classified as habitual morning vs. evening workers on the basis of their answers to a questionnaire, were compared with regard to catecholamine excretion under conditions of relaxation in the morning and in the evening. It was shown that individuals who preferred to work in the evening, excreted more adrenaline in the evening than in the morning, while individuals characterized by morning alertness excreted more adrenaline in the morning than in the evening, also when relaxing. With regard to noradrenaline excretion there was no marked difference between the groups.