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Endocrine Rhythms Across Reversal Sleep-Wake Cycles.

Parker-DC; Rossman-LG; Pekary-AE; Hershman-JM; Kripke-DF; Gibson-W
NIOSH 1981 Jul:151-180
The effects of phase reversal of the sleep wake cycle on endogenous daily patterns of release of human growth hormone, prolactin, thyrotropin, and cortisol were studied. Blood was sampled from eight young adult males at 30 minute intervals across 24 to 72 hour sampling periods. Reversal of the sleep phase (SP) was achieved by delaying bedtime from 2300 hours until 1100 hours on the first day of reversal and then maintaining the bedtime sleep segment in this 1100 to 1900 hour interval. Four subjects were studied in an acute sleep wake (SW) reversal protocol which consisted of a 72 hour sampling period of serial 24 hour long basal (B), first (R1) and second (R2) reversal segments. The other four subjects continued their SW schedule for 15 days. The actigraph of somatotropin (hGH) showed daily peak early in nocturnal sleep, shifted rapidly into early daytime sleep on R1 and held in this position for the rest of the 15 days of SW reversal. Both basal and reversal growth hormone patterns showed multiple peaks in wakefulness. The second major synchronized peak of the day also occurred in late sleep. The reversals in hGH indicated its SW rhythmicity. Daily maxima of prolactin in relation to sleep consistently characterized both basal and reversal conditions. The average cortisol basal pattern was characterized by unimodal nonsinusoidal waveform. The data indicated the presence of bimodal components. Group mean acrophases followed the advancement of the basal circadian cortisol peak component. The basal pattern of thyrotropin showed the usual evening presleep peak whose maximum was close to sleep onset, indicating circadian sleep masking and sleep phasing effects. Testosterone and perhaps young adult male luteinizing hormone also exhibited sleep stimulatory masking.
Hormone-activity; Biological-function; Biological-rhythms; Endocrinology; Sleep-disorders; Corticoids; Endocrine-function; Humans;
Publication Date
Document Type
Conference/Symposia Proceedings;
Fiscal Year
NTIS Accession No.
NTIS Price
Identifying No.
(NIOSH) 81-127
NIOSH Division
Source Name
The Twenty-Four Hour Workday: Proceedings of a Symposium on Variations in Work-Sleep Schedules, Division of Biomedical and Behavioral Science, NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio, DHHS (NIOSH) Publication No. 81-127