Endocrine Rhythms, the Sleep-Wake Cycle, and Biological Clocks

Copinschi, Georges; Challet, Étienne

doi:10.1016/b978-0-323-18907-1.00009-3

Cited by 16 publications

(16 citation statements)

References 297 publications

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“…In fact, 2-AG fills a unique role because it is an orexigenic mediator that exhibits its highest concentrations in midday and lowest during sleep. Neither the hormones controlled by the HPA axis nor adipokines and gut hormones reach peak concentrations in the middle of the normal feeding period (Copinschi et al, 2010).…”

Section: Relationships Of Endocannabinoid Concentrations With Time Ofmentioning

confidence: 99%

Circulating Endocannabinoids: From Whence Do They Come and Where are They Going?

Hillard

2017

Neuropsychopharmacol.

347

241

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The goal of this review is to summarize studies in which concentrations of circulating endocannabinoids in humans have been examined in relationship to physiological measurements and pathological status. The roles of endocannabinoids in the regulation of energy intake and storage have been well studied and the data obtained consistently support the hypothesis that endocannabinoid signaling is associated with increased consumption and storage of energy. Physical exercise mobilizes endocannabinoids, which could contribute to refilling of energy stores and also to the analgesic and mood-elevating effects of exercise. Circulating concentrations of 2-arachidonoylglycerol are very significantly circadian and dysregulated when sleep is disrupted. Other conditions under which circulating endocannabinoids are altered include inflammation and pain. A second important role for endocannabinoid signaling is to restore homeostasis following stress. Circulating endocannabinoids are stress-responsive and there is evidence that their concentrations are altered in disorders associated with excessive stress, including post-traumatic stress disorder. Although determination of circulating endocannabinoids can provide important information about the state of endocannabinoid signaling and thus allow for hypotheses to be defined and tested, the large number of physiological factors that contribute to their circulating concentrations makes it difficult to use them in isolation as a biomarker for a specific disorder.

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Section: Relationships Of Endocannabinoid Concentrations With Time Ofmentioning

confidence: 99%

Circulating Endocannabinoids: From Whence Do They Come and Where are They Going?

Hillard

2017

Neuropsychopharmacol.

347

241

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“…In humans, under normal conditions, the 24-hour profiles of ACTH and cortisol show an early morning maximum, declining levels throughout daytime, a quiescent period of minimal secretory activity usually centered around midnight, and an abrupt elevation during late sleep culminating in an early morning maximum ( 113 ). An example of simultaneous profiles of ACTH and cortisol in a healthy young man studied under normal conditions is shown in Figure 5 .…”

Section: The Circadian Rhythmicity Of Glucocorticoid Releasementioning

confidence: 99%

“…This phenomenon is called the cortisol awakening response and appears to be independent of circadian regulation ( 246 ). The combination of the sleep onset inhibition of HPA activity with the post-awakening stimulation enhances the amplitude of the human cortisol rhythm by about 15% ( 113 ).…”

Section: Impact Of Circadian Rhythmicity On the Physiological Effementioning

confidence: 99%

“…The absence or the marked dampening of cortisol circadian variations in Cushing’s syndrome has obvious diagnostic implications because the time of day when blood samples are obtained has to be taken into account in the evaluation of the result. Differentiation between normal and pathological levels is greatly improved by adequately selecting the sampling time because the overlap between normal individual values and values in patients with Cushing’s syndrome is minimal during a 4-hour interval centered around midnight ( 113 ). The reduced amplitude of the circadian cortisol rhythm associated with higher nadir levels is, in clinical practice, an early marker of hypercortisolism in humans, and the evaluation of cortisol levels during the normal nadir of the rhythm is a common screening test to diagnose Cushing’s syndrome ( 357 ).…”

Section: Conditions Of Abnormal Circadian Rhythmicity Of Circulatmentioning

confidence: 99%

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The Functional and Clinical Significance of the 24-Hour Rhythm of Circulating Glucocorticoids

et al. 2016

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ESSENTIAL POINTSThe daily rhythmicity of plasma glucocorticoid (GC) levels is a strong modulator of many physiological and psychological processes, although its functional significance is poorly understood.The suprachiasmic nuclei of the hypothalamus have been shown to harbor a molecular clock mechanism generating circadian rhythmicity in mammals, but the same mechanism is present in many peripheral tissues and elsewhere in the brain.Mineralocorticoid receptors and glucocorticoid receptors mediate the action of naturally occurring GC in complementary fashion.Optimal physiological effects of GC occur when the central signal that controls the rhythm of GC release and the peripheral rhythms in tissues expressing GC receptors are aligned.New studies suggest that misalignment of central and peripheral oscillators may increase the risk of disease, with adverse effects on the immune system, cardiovascular system and metabolism, among others prominent.Chronopharmacological strategies that attempt to normalize the rhythm of circulating GCs have potential to improve the treatment of a wide variety of physical and mental conditions.

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“…Although glucocorticoid secretion peaks at the light offset, 41 and NE is released with a nocturnal peak from the SCG in rodents, 42 these rhythms are antiphasic in nocturnal and diurnal animals. [41][42][43][44] IOP is elevated at night in nocturnal mice (Fig. 1), 7,12 diurnal humans, and monkeys.…”

Section: Discussionmentioning

confidence: 94%

Circadian Regulation of IOP Rhythm by Dual Pathways of Glucocorticoids and the Sympathetic Nervous System

Ikegami

Shigeyoshi

Masubuchi

2020

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. Elevated IOP can cause the development of glaucoma. The circadian rhythm of IOP depends on the dynamics of the aqueous humor and is synchronized with the circadian rhythm pacemaker, that is, the suprachiasmatic nucleus. The suprachiasmatic nucleus resets peripheral clocks via sympathetic nerves or adrenal glucocorticoids. However, the detailed mechanisms underlying IOP rhythmicity remain unclear. The purpose of this study was to verify this regulatory pathway. METHODS. Adrenalectomy and/or superior cervical ganglionectomy were performed in C57BL/6J mice. Their IOP rhythms were measured under light/dark cycle and constant dark conditions. Ocular administration of corticosterone or norepinephrine was also performed. Localization of adrenergic receptors, glucocorticoid receptors, and clock proteins Bmal1 and Per1 were analyzed using immunohistochemistry. Period2::luciferase rhythms in the cultured iris/ciliary bodies of adrenalectomized and/or superior cervical ganglionectomized mice were monitored to evaluate the effect of the procedures on the local clock. The IOP rhythm of retina and ciliary epithelium-specific Bmal1 knockout mice were measured to determine the significance of the local clock. RESULTS. Adrenalectomy and superior cervical ganglionectomy disrupted IOP rhythms and the circadian clock in the iris/ciliary body cultures. Instillation of corticosterone and norepinephrine restored the IOP rhythm. β2-Adrenergic receptors, glucocorticoid receptors, and clock proteins were strongly expressed within the nonpigmented epithelia of the ciliary body. However, tissue-specific Bmal1 knockout mice maintained their IOP rhythm. CONCLUSIONS. These findings suggest direct driving of the IOP rhythm by the suprachiasmatic nucleus, via the dual corticosterone and norepinephrine pathway, but not the ciliary clock, which may be useful for chronotherapy of glaucoma.

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Endocrine Rhythms, the Sleep-Wake Cycle, and Biological Clocks

Cited by 16 publications

References 297 publications

Circulating Endocannabinoids: From Whence Do They Come and Where are They Going?

Circulating Endocannabinoids: From Whence Do They Come and Where are They Going?

The Functional and Clinical Significance of the 24-Hour Rhythm of Circulating Glucocorticoids

Circadian Regulation of IOP Rhythm by Dual Pathways of Glucocorticoids and the Sympathetic Nervous System

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