INVERSION OF THE DIURNAL VARIATION OF UROPEPSIN OUTPUT IN NIGHT-SHIFT WORKERS

Abstract

In the first experiment, twenty-four healthy lmale volunteers were used as subjects. Their ives were shifted exactly by 12 hours, and the time of sleeping and of taking meal were kept same for all subjects. Urine was collected for every two hours while they were awake at night and in the lump while they were asleep in the day-time. An activity level of uropepsin was assayed by the West's method. On the third day of night-shift, the ratio of the uropepsin output at night to that in the day-time was turned, except for two persons whose diurnal changes of the uropepsin excretion were extremely irregular. Activity levels of these exceptional subjects got increased during the night on the whole with passing days. In the second place, nine nurses working in three shifts were also employed as subjects. A comparrison between uropepsin outputs during their duty at night and during sleep in the day-time was made. In all cases, activity levels of uropepsin were found to be higher at night than in the day-time. From findings above-mentioned as well as those obtained by others, the author infers that the diurnal rhythm of physiological conditions could completely be reversed, though difficult, under a suitable management. Therefore, the diurnal curve of the physiochemical capacity in the human subject may be obvious to intrinsically be re-adjusted by the way of life, but not by astrophisical influences.