Food and the circadian activity of the hypothalamic-pituitary-adrenal axis

Leal, Ângela M. O.; Moreira, Ayrton Custódio

doi:10.1590/s0100-879x1997001200003

Cited by 52 publications

(26 citation statements)

References 163 publications

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“…The major action of the environment is to synchronize the circadian rhythms by frequent periodic signals, such as light-dark, rest-activity and sleep-wake cycles, food ingestion and social cues (22,23). Therefore, we also evaluated the timing of the emergence of the 24-h rhythm of sleep and wakefulness in these premature babies.…”

Section: Circadian Rhythm Ontogenymentioning

confidence: 99%

Salivary cortisol as a tool for physiological studies and diagnostic strategies

Castro

Elias

Martinelli

et al. 2000

Braz J Med Biol Res

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Salivary cortisol is an index of plasma free cortisol and is obtained by a noninvasive procedure. We have been using salivary cortisol as a tool for physiological and diagnostic studies, among them the emergence of circadian rhythm in preterm and term infants. The salivary cortisol circadian rhythm in term and premature infants was established between 8 and 12 postnatal weeks. In the preterm infants the emergence of circadian rhythm was parallel to the onset of sleep rhythm. We also studied the use of salivary cortisol for screening for Cushings syndrome (CS) in control and obese outpatients based on circadian rhythm and the overnight 1 mg dexamethasone (DEX) suppression test. Salivary cortisol was suppressed to less than 100 ng/ dl after 1 mg DEX in control and obese patients. A single salivary cortisol measurement at 23:00 h and again after 1 mg DEX above the 90th percentile of the obese group values had sensitivity and specificity of 93 and 93% (23:00 h), and 91 and 94% (after DEX), respectively. The sensitivity improved to 100% when we combined both parameters. We also studied 11 CS children and 21 age-matched primary obese children for whom salivary cortisol sensitivity and specificity were 100/95% (23:00 h), and 100/95% (1 mg DEX), respectively. Similar to adults, sensitivity and specificity of 100% were obtained by combining 23:00 h and 1 mg DEX. The measurement of salivary cortisol is a useful tool for physiological studies and for the diagnosis of CS in children and adults on an outpatient basis. Correspondence

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Section: Circadian Rhythm Ontogenymentioning

confidence: 99%

Salivary cortisol as a tool for physiological studies and diagnostic strategies

Castro

Elias

Martinelli

et al. 2000

Braz J Med Biol Res

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“…Although the function of this oscillation in secretion is not well understood, it is thought to be important for energy balance, because diet and feeding time have an impact on secretion rhythm (5)(6)(7). Diet composition (8) and timing of feeds have also been shown to modulate the circadian pacemaker (9,10), and a connection between the pacemaker and the oscillations in glucocorticoid secretion has been observed (8,11,12).…”

mentioning

confidence: 99%

Glucocorticoid regulation of the circadian clock modulates glucose homeostasis

Bernal²,

Pillsbury³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

345

286

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Circadian clock genes are regulated by glucocorticoids; however, whether this regulation is a direct or secondary effect and the physiological consequences of this regulation were unknown. Here, we identified glucocorticoid response elements (GREs) at multiple clock genes and showed that 3 were directly regulated by the glucocorticoid receptor. We determined that a GRE within the core clock gene Per2 was continuously occupied during rhythmic expression and essential for glucocorticoid regulation of that gene in vivo. We further demonstrated that mice with a genomic deletion spanning this GRE expressed elevated leptin levels and were protected from glucose intolerance and insulin resistance on glucocorticoid treatment but not from muscle wasting. We conclude that Per2 is an integral component of a particular glucocorticoid regulatory pathway and that glucocorticoid regulation of the peripheral clock is selectively required for some actions of glucocorticoids.circadian rhythm ͉ diabetes ͉ nuclear receptors ͉ metabolic syndrome

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“…The paradoxical increase in body weight despite food restriction reported earlier (16,17) illustrates the adaptation of the animals to the model during the selected period. In addition, confirming this adaptation, the cyclic presentation of food for a fixed period of time caused entrainment (1,19) of the circadian cycle, rendering these nocturnal animals awake and very active, expecting food, while the others in the vivarium were sleeping. The animals in the AF group were very active and drank much more water than the other groups.…”

mentioning

confidence: 64%

“…This behavior consists of many different components, and different brain systems are involved in the regulation of its specific aspects. As a biological rhythm, feeding behavior is organized mainly in the diencephalon by the lateral and medial hypothalamus subdivisions and the paraventricular nucleus (1)(2)(3). The lateral hypothalamus seems to control blood glucose homeostasis through glucoreceptors (also present in the nucleus tractus solitarius and the liver).…”

mentioning

confidence: 99%

Involvement of the caudal raphe nuclei in the feeding behavior of rats

Takase

Barone

Nogueira

2000

Braz J Med Biol Res

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Involvement of the caudal raphe nuclei (raphe pallidus, RPa; raphe magnus, RMg, and raphe obscurus, ROb) in feeding behavior of adult rats was studied by measuring c-Fos protein expression, in animals submitted to the meal-feeding model of food restriction in which the rats were fed ad libitum only from 7:00 to 9:00 h, for 15 days. The experimental groups submitted to chronic fasting, named search for food (SF), ingestion of food (IF) and satiety of food (SaF) were scheduled after a previous study in which the body weight and the general and feeding behaviors were evaluated by daily monitoring. Acute, 48-h fasting (AF) was used as control. In the chronic group, the animals presented a 16% reduction in body weight in the first week, followed by a continuous, slow rise in weight over the subsequent days. Entrainment of the sleep-wake cycle to the schedule of food presentation was also observed. The RPa was the most Fos immunopositive nucleus in the chronic fasting group, followed by the RMg. The ANOVA and Tukey test (P<0.05) confirmed these results. The IF group was significantly different from the other three groups, as also was the number of labeled cells in the RPa in SF and IF groups. Nevertheless, no significant difference was observed between RMg and RPa, or RMg and ROb in the SaF and AF. However, it is interesting to observe that the groups in which the animals were more active, searching for or ingesting food, presented a larger number of labeled cells. These results suggest a different involvement of the caudal raphe nuclei in the somatic and autonomic events of feeding behavior, corroborating the functions reported for them earlier. Feeding behavior is a complex group of functions that comprise the search, capture and ingestion of the organic and inorganic matter necessary for the sustenance of life. This behavior consists of many different components, and different brain systems are involved in the regulation of its specific aspects. As a biological rhythm, feeding behavior is organized mainly in the diencephalon by the lateral and medial hypothalamus subdivisions and the paraventricular nucleus (1-3). The lateral hypothalamus seems to control blood glucose homeostasis through glucoreceptors (also present in the nucleus tractus solitarius and the liver). Once stimulated, these receptors trigger reflexes that restore glycemia through metabolic activity of the liver, which in turn, initiates feeding behavior, particularly the searching and ingestion phases (4). Satiety, however, seems to be driven by the ventromedial hypothalamic subdivision through the release of gut hormones and cholecystokinin, and also by the distension of the gastrointestinal tract

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Food and the circadian activity of the hypothalamic-pituitary-adrenal axis

Cited by 52 publications

References 163 publications

Salivary cortisol as a tool for physiological studies and diagnostic strategies

Salivary cortisol as a tool for physiological studies and diagnostic strategies

Glucocorticoid regulation of the circadian clock modulates glucose homeostasis

Involvement of the caudal raphe nuclei in the feeding behavior of rats

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