CORTICOTROPIC AXIS: The nycthemeral pattern of @entity701 is a good marker of the circadian clock. @entity701 levels fluctuate between a peak level, observed in the early hours of the morning, and a minimal level around midnight. This variability is considerably reduced or even abolished in @entity699 . THYREOTROPIC AXIS: The nycthemeral pattern of TSH secretion is dependent on both the circadian clock and sleep (which inhibits hormone secretion). The moment of the evening rise is a reliable marker of the circadian rhythmicity. SOMATOTROPIC AXIS: @entity2124 is essentially pulsatile. GH levels are often undetectable between pulses. The circadian rhythmicity plays only a minor role in the regulation of @entity2124 secretion. LACTOTROPIC AXIS: Nycthemeral variations in prolactin secretion are mainly regulated by wake-sleep cycles; peak levels occur in the middle of the night. Prolactin secretion is also modulated by the circadian rhythmicity. GONADOTROPIC AXIS: Gonadotropins are secreted in pulses, following the pulses of @entity1176 secretion. In adult @entity1 , nycthemeral variations in LH are strongly modulated by the menstrual cycle. MELATONIN: The nychtemeral pattern of @entity2493 is an excellent marker of the circadian clock. Diurnal concentrations are low and vary little whereas peak levels are observed in the middle of the night. @entity2493 rhythmicity is not influenced by sleep, but is dependent on exposure to light and darkness.

[Biologic rhythms. Nyctemeral variation in XXXX ].

@entity1 :: ('9606', 'Species') :: ['women'] @entity699 :: ('MESH:D003480', 'Disease') :: ['Cushing s syndrome'] @entity2124 :: ('2688', 'Gene') :: ['growth hormone', 'Growth hormone'] @entity2493 :: ('MESH:D008550', 'Chemical') :: ['melatonin', 'Melatonin'] @entity701 :: ('MESH:D006854', 'Chemical') :: ['Cortisol', 'cortisol'] @entity1176 :: ('MESH:D007987', 'Chemical') :: ['GnRH']
@entity1 :: (9606,Species) :: ['man']
