Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Shift work  (1)
  • Urinary steroids  (1)
  • 1
    ISSN: 1439-6327
    Keywords: Shift work ; Melatonin ; Cortisol ; Testosterone ; Prolactin ; Circadian rhythm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a study of the internal desynchronization of circadian rhythms in 12 shift workers, 4 of them, aged 25–34 years, agreed to be sampled every 2 h during their night shift (0000 hours to 0800 hours). They were oil refinery operators with a fast rotating shift system (every 3–4 days). We found marked changes in the secretory profiles of melatonin, prolactin and testosterone. Melatonin had higher peak-values resulting in a four-times higher amplitude than in controls. With respect to prolactin and testosterone, peak and trough times were erratic and the serum concentrations were significantly decreased in shift workers. Serum cortisol presented a decreased rhythm amplitude together with higher concentrations at 0000 hours in shift workers. This study clearly shows that fast rotating shift-work modifies peak or trough values and rhythm amplitudes of melatonin, prolactin, testosterone and cortisol without any apparent phase shift of these hormones. Whether the large rhythm amplitude of melatonin may be considered as a marker of tolerance to shift work, as reported for body temperature and hand grip strength, since it would help the subjects to maintain their internal synchronization, needs further investigation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European journal of applied physiology 56 (1987), S. 403-411 
    ISSN: 1439-6327
    Keywords: Sleep ; Alertness ; Circadian ; Temperature ; Urinary steroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present study compares the effects on sleep and the subsequent period of wakefulness of delaying bedtime of 2 h or advancing rising time by 2 h in subjects clearly differentiated by morningness or eveningness in their circadian rhythms. Twelve young healthy good sleepers, six morning types (MT) and six evening types (ET), were selected. The data obtained from the second 24 h (night and day) with delayed bedtime (DB) and advanced rising time (AR) were compared with those obtained in the reference condition (R) with normal sleep schedules. Sleep was recorded polygraphically and rectal temperature was continuously monitored during the nights and during the day following the second night of each condition. Subjective estimations of alertness, performance tasks and urinary steroids were analysed. Early rising appeared to be more disturbing than a late bedtime. The second shortened night showed fewer characteristics of recovery sleep in AR than in DB. The decrease in self rated alertness was a function both of the type of condition (DB or AR) and of the morning-evening typology of the subject. The largest decrease was observed in AR and in the ET subjects. AR also resulted in the most pronounced decrease in performance tasks and in an increase in urinary 17 ketosteroids without change in the 17 hydroxy-corticosteroids. The effects on rectal temperature were limited to short periods after bedtime in DB and rising time in AR.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...