. 2004 , Laermans et al . 2015 ). Diurnal rhythms in plasma ghrelin levels and gastric ghrelin expression are abolished in mice that lack the core clock gene Bmal1 , indicating that ghrelin levels are regulated by the circadian clock ( Laermans et al
Anneleen Segers, Louis Desmet, Shu Sun, Kristin Verbeke, Jan Tack, and Inge Depoortere
Muneki Ikeda, Yasushi Hojo, Yoshimasa Komatsuzaki, Masahiro Okamoto, Asami Kato, Taishi Takeda, and Suguru Kawato
), the CORT level changes in both the plasma and brain along the circadian rhythm ( Migeon et al . 1956 , Moore & Eichler 1972 , Qian et al . 2012 ). Qian et al . showed the high synchronicity of CORT oscillation between the blood and hippocampus by
Adrián Báez-Ruiz, Natalí N Guerrero-Vargas, Fernando Cázarez-Márquez, Elizabeth Sabath, María del Carmen Basualdo, Roberto Salgado-Delgado, Carolina Escobar, and Ruud M Buijs
with the disturbance in the rhythm of food intake is important for metabolic dysregulation. In this sense, alteration of daily secretion of glucocorticoids and melatonin caused by circadian disruption (shift-work, extended illumination exposure or
Miho Sato, Keiko Nakahara, Mikiya Miyazato, Kenji Kangawa, and Noboru Murakami
expression is regulated by circadian rhythm, starvation, CCK, gastrin, and other factors, possibly via extracellular fluid or satellite cells. CCK and gastrin receptors are expressed in vagal afferent neurons, implying that the regulation of GHS-R gene
Qinghua Wang, Jing Tang, Shujun Jiang, Zan Huang, Anying Song, Siyuan Hou, Xiang Gao, and Hai-Bin Ruan
), ITA and XIAP ( Jordan et al. 2001 ), UNC5H1 ( Williams et al. 2003 ), ROR2 ( Matsuda et al. 2003 ) and RORα ( Wang et al. 2010 ) to regulate neural development, cell apoptosis and proliferation and circadian rhythm. We and others have showed
SW Lockley, DJ Skene, K James, K Thapan, J Wright, and J Arendt
Although melatonin treatment has been shown to phase shift human circadian rhythms, it still remains ambiguous as to whether exogenous melatonin can entrain a free-running circadian system. We have studied seven blind male subjects with no light perception who exhibited free-running urinary 6-sulphatoxymelatonin (aMT6s) and cortisol rhythms. In a single-blind design, five subjects received placebo or 5 mg melatonin p.o. daily at 2100 h for a full circadian cycle (35-71 days). The remaining two subjects also received melatonin (35-62 days) but not placebo. Urinary aMT6s and cortisol (n=7) and core body temperature (n=1) were used as phase markers to assess the effects of melatonin on the During melatonin treatment, four of the seven free-running subjects exhibited a shortening of their cortisol circadian period (tau). Three of these had taus which were statistically indistinguishable from entrainment. In contrast, the remaining three subjects continued to free-run during the melatonin treatment at a similar tau as prior to and following treatment. The efficacy of melatonin to entrain the free-running cortisol rhythms appeared to be dependent on the circadian phase at which the melatonin treatment commenced. These results show for the first time that daily melatonin administration can entrain free-running circadian rhythms in some blind subjects assessed using reliable physiological markers of the circadian system.
. In addition, fasted adult offspring from FR70 dams during gestation displayed no marked reduced α-MSH-immunoreactive fibre projection intensity in the PVN ( Breton et al . 2009 ). Maternal reduced nutrition modifies circadian rhythms in the offspring
The circadian rhythm of urinary 17-hydroxycorticosteroid (17-OHCS) excretion in Europeans and Equatorial Amerindians has been compared. The precise daily habits of the Equatorial Amerindians did not result in a more marked rhythm of 17-OHCS excretion. Amerindian men and women excreted much less 17-OHCS than their European counterparts; the difference is still substantial when body weight is taken into consideration. The rhythm of 17-OHCS excretion in Amerindians had a minimum and maximum corresponding to their early reveille and bedtime confirming the importance of environmental stimuli in setting the timing of the rhythm.
J L Crawford, B P Thomson, M F Beaumont, and D C Eckery
1984 ). Daily changes in melatonin secretion also result in a prominent circadian rhythm of Prl secretion in the ram during long days; however, the timing of this cycle shifted and the rate of secretion diminished after exposure to short days
Yvan Touitou, Michel Lagoguey, André Bogdan, Alain Reinberg, and Hervé Beck
Circannual changes of immunoreactive LH and FSH were documented on a circadian basis in January, March, June and October in four groups of subjects: seven young men, six elderly men, six elderly women and six men and women suffering from senile dementia. The sampling was serially dependent only for the young men and the core subgroups of elderly men and elderly women. A circadian rhythm for FSH was not detected in any group of subjects during any of the sampling sessions, whereas a circadian rhythm for LH was detected twice (June and October) in young men, once (October) in elderly demented patients, and not at all in the groups of elderly men and women. Both 24-h and yearly mean levels of gonadotrophins were higher in elderly subjects (two-to 25-fold according to the hormone, sex and season) than in young men. Circannual rhythms of plasma LH with large amplitudes were validated by the cosinor method, with an acrophase located in April or May. A circannual rhythm of plasma FSH was validated only in young men, with an acrophase in October. The persistence of a circannual rhythm of plasma LH with large amplitude in elderly subjects, associated with high mean levels of the hormone, especially in elderly women, suggests that this bioperiodicity of the pituitary gland is independent of gonadal function.