par Van Cauter, Eve ;Refetoff, Samuel
Référence Journal of endocrinological investigation, 8, 4, page (381-391)
Publication Publié, 1985
Article révisé par les pairs
Résumé : We have shown evidence challenging the currently prevailing view that 24-h rhythms of a pituitary hormone is released either sleep-related or dependent on a master circadian clock. Instead, the temporal organization of pituitary hormone release appears to be controlled by multiple factors. For every pituitary hormone, intrinsic circadian rhythmicity and sleep-related components interact to produce the overt 24-h pattern of plasma concentrations. Meals and other external factors may also elicit transient changes in the circulating levels of these hormones. Previous studies of alterations of the human circadian organization associated with time shifts or temporal isolation followed the evolution of a single time point throughout the investigation span. Examples of such chronobiological markers are the daily maximum of the rhythm of body temperature and the acrophase of the 24-h profile of plasma cortisol levels. Such markers have been considered to reflect the synchronization of the entire rhythm. The present review indicates that a valid estimation of the adaptation of 24-h hormonal variation to changes in environmental time requires the analysis of more than a single reference point in the waveform and emphasizes the importance of methods providing detailed quantitative descriptions of such waveforms.