Objective: To explore the developmental characteristics of circadian rhythms in hypothalamus-pituitary-adrenal (HPA) axis during puberty. Methods: A total of 1 070 students from Grade 2-3 in 3 primary schools in Ma'anshan city, Anhui province, were selected for physical examination and circadian rhythm of HPA axis checked from 2015 to 2017. Saliva samples were collected at each of the following three time points: immediately upon wakening, 30 minutes after wakening and bedtime, with the index of circadian rhythm of HPA axis calculated, which including cortisol awake response (CAR), cortisol in puberty priming and diurnal cortisol slope (DCS). Testicular volume, palpation and visual inspection of breast development were used to assess the state of purbety development on boys and girls. Information on gender, date of birth, time to fall asleep, wake-up time and weekly physical activity were gathered through questionnaire survey. Non-parametric test was used to compare the differences of baseline, follow-up period and different adolescent developmental processes of each index on circadian rhythm of HPA axis. Results: During the period of follow-up program and comparing with the continuous undeveloped group, CAR and the changes of CAR showed significantly increase, both in the puberty priming group and continuous development group, with statistically significant differences (CAR: Z=8.551, 4.680, respectively; P<0.01; the changes of CAR: Z=4.079, 2.700, respectively, P<0.01). There were no significant differences noticed in CAR and the changes of CAR between puberty priming group or continuous development group. The area under the curve (AUC) of cortisol in puberty priming group was slightly higher than that in the persistent undeveloped group (Z=2.591, P=0.010). Both the changes of daily cortisol slope (DCS) in puberty priming group and continuing developed group decreased significantly, when comparing with those in continuous undeveloped group (Z=-2.450, Z=-2.151; all P<0.05). There was no significant difference noticed in the changes of cortisol in puberty priming and DCS between different puberty development stages (the changes of AUC: χ(2)=2.747, P=0.253; DCS: χ(2)=4.554, P=0.032). Conclusions: The indexes of circadian rhythm of HPA axis were associated with the development of puberty. Both the cortisol awakening response and the total amount of diurnal cortisol secretion showed an increase, along with the puberty development. The change of diurnal cortisol slope declined with the development of puberty.
Adolescent ; Area Under Curve ; Circadian Rhythm ; Female ; Humans ; Hydrocortisone ; Hypothalamo-Hypophyseal System ; Male ; Pituitary-Adrenal System ; Pregnancy ; Saliva ; Sexual Maturation/physiology* ; Surveys and Questionnaires ; Wakefulness

OBJECTIVETo systematically review the updated information about the gut microbiota-brain axis.

DATA SOURCESAll articles about gut microbiota-brain axis published up to July 18, 2016, were identified through a literature search on PubMed, ScienceDirect, and Web of Science, with the keywords of "gut microbiota", "gut-brain axis", and "neuroscience".

STUDY SELECTIONAll relevant articles on gut microbiota and gut-brain axis were included and carefully reviewed, with no limitation of study design.

RESULTSIt is well-recognized that gut microbiota affects the brain's physiological, behavioral, and cognitive functions although its precise mechanism has not yet been fully understood. Gut microbiota-brain axis may include gut microbiota and their metabolic products, enteric nervous system, sympathetic and parasympathetic branches within the autonomic nervous system, neural-immune system, neuroendocrine system, and central nervous system. Moreover, there may be five communication routes between gut microbiota and brain, including the gut-brain's neural network, neuroendocrine-hypothalamic-pituitary-adrenal axis, gut immune system, some neurotransmitters and neural regulators synthesized by gut bacteria, and barrier paths including intestinal mucosal barrier and blood-brain barrier. The microbiome is used to define the composition and functional characteristics of gut microbiota, and metagenomics is an appropriate technique to characterize gut microbiota.

CONCLUSIONSGut microbiota-brain axis refers to a bidirectional information network between the gut microbiota and the brain, which may provide a new way to protect the brain in the near future.

Animals ; Brain ; metabolism ; physiology ; Central Nervous System ; metabolism ; physiology ; Gastrointestinal Microbiome ; physiology ; Gastrointestinal Tract ; microbiology ; Humans ; Hypothalamo-Hypophyseal System ; metabolism ; physiology ; Pituitary-Adrenal System ; metabolism ; physiology

OBJECTIVETo investigate the effect of Chinese medicine (CM) Schisandra chinensis on interleukin (IL), glucose metabolism, and pituitary-adrenal and gonadal axis of rats after strenuous navigation and exercise.

METHODSA total of 45 Sprague-Dawley rats were randomized into the quiet control group, the stress group, and the CM group (15 in each group). The CM group received 2.5 g/kg of Schisandra chinensis twice per day for one week before modeling. Except the quiet controls, rats were trained using the Bedford mode for 10 days. On the 11th day, they performed 3 h of stressful experimental navigation and 3 h of strenuous treadmill exercise. The levels of serum testosterone (T), cortisol (CORT), luteinizing hormone (LH), IL-1, IL-2, and IL-6 were tested by radioimmunoassay and enzyme-linked immunosorbent assay, respectively. The adrenal cortex ultrastructure was observed using electron microscopy.

RESULTSCompared with the quiet control group, after navigation and strenuous exercise, blood glucose was increased, and T level was decreased in the stress group (both P<0.01). The blood glucose, CORT, IL-1 and IL-2 levels were significantly reduced in the CM group (P<0.05 or P<0.01) as compared with the stress group. Electron microscopy revealed that the rats in the CM group had a smaller decrease in adrenal intracellular lipid droplets and higher levels of apoptosis than those in the stress group.

CONCLUSIONSSchisandra chinensis can reduce serum CORT and blood glucose levels in stressed rats. It appears to protect the cell structure of the adrenal cortex, and offset the negative effects of psychological stress and strenuous exercise related to immune dysfunction. Schisandra chinensis plays a regulatory role in immune function, and can decrease the influence of stress in rats.

Adrenal Cortex ; pathology ; ultrastructure ; Animals ; Blood Glucose ; metabolism ; Glucose ; metabolism ; Gonads ; drug effects ; metabolism ; Hydrocortisone ; blood ; Interleukin-1 ; blood ; Interleukin-2 ; blood ; Interleukin-6 ; blood ; Interleukins ; blood ; Luteinizing Hormone ; blood ; Male ; Physical Conditioning, Animal ; Pituitary-Adrenal System ; drug effects ; metabolism ; Plant Extracts ; pharmacology ; Rats, Sprague-Dawley ; Schisandra ; chemistry ; Swimming ; physiology ; Testosterone ; blood

This study was aimed to investigate the changes of the hypothalamic-pituitary-adrenal axis (HPAA) activity and the cytokines system in the hypothalamus of the depressive rats which were exposed to chronic unpredictable mild stressors (CUMS) after middle cerebral artery occlusion (MCAO). By means of qRT-PCR, ELISA and Western blot, mRNA and/or protein expressions of corticotropin releasing factor (CRF), tumor necrosis factors-α (TNF-α), suppressor of cytokines signaling 3 (SOCS3), phosphorylation of signal transducers and activators of transcription 3 (pSTAT3) were measured in the hypothalamus of rats. The results showed that, compared with control group, CUMS+MCAO group exhibited increased mRNA levels of CRF, TNF-α, SOCS3, as well as up-regulated CRF, TNF-α, SOCS3 and pSTAT3 protein expressions. Furthermore, there were correlations between CRF and TNF-α, TNF-α and SOCS3, SOCS3 and pSTAT3, respectively. These observations indicated the CRF system was activated in the post stroke depression (PSD) status. The TNF-α and its signaling pathway, STAT3/SOCS3, were up-regulated in mRNA and protein levels. In conclusion, this study presents the evidence which supports the hypothesis of signaling cross-talk between the CRF system and TNF-α signaling pathway after ischemic stroke and CUMS.
Animals ; Hypothalamo-Hypophyseal System ; physiology ; Hypothalamus ; physiology ; Infarction, Middle Cerebral Artery ; Phosphorylation ; Pituitary-Adrenal System ; physiology ; Rats ; STAT3 Transcription Factor ; metabolism ; Signal Transduction ; Suppressor of Cytokine Signaling 3 Protein ; Suppressor of Cytokine Signaling Proteins ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism ; Up-Regulation

Depression and insomnia are intimately related. Depressed patients usually manifest sleep discontinuity and early awakening, reduced or no slow wave sleep (SWS) and shortened latency of rapid eye movement (REM) sleep. These sleep abnormalities are very similar to those caused by over activated hypothalamic-pituitary-adrenal (HPA) axis with stress. Therefore, the animal models developed by post-traumatic stress disorder or chronic unpredictable mild stress could be used to evaluate drugs which have effects of both anti-depression and improvement of sleep quality, and to provide a more reliable platform for further studis on the mechanisms of depression and accompanied insomnia. This review mainly focuses on the typical features of sleep disturbance of depression, possible pathophysiological mechanisms, establishment of animal stress models and analysis of their abnormal sleep characteristics.
Animals ; Chronic Disease ; Depression ; physiopathology ; Depressive Disorder ; physiopathology ; Disease Models, Animal ; Humans ; Hypothalamo-Hypophyseal System ; physiopathology ; Pituitary-Adrenal System ; physiopathology ; Sleep ; physiology ; Sleep Initiation and Maintenance Disorders ; physiopathology ; Sleep, REM ; Stress Disorders, Post-Traumatic ; physiopathology ; Stress, Psychological ; physiopathology

OBJECTIVETo explore the changes of Treg-Th17 balance influenced by corticosterone, major effect hormone of hypothalamic-pituitary-adrenal (HPA) axis under running stress.

METHODSA total of 25 corticotropin-releasing hormone (CRH) wildtype (CRH+/+) and knockout (CRH-/-) mice were adopt and divided into 4 groups as follows: CRH+/+ ctrl, CRH+/+ stress, CRH-/- ctrl and CRH-/- stress. All mice in stress groups were under 2 h running. After 1 h, blood plasma in all groups was collected and the expression of corticosterone and IL-17A was detected by ELISA. Meanwhile, unicell suspensions of peripheral lymph node and spleen in each group were prepared too and stained by PE-CD4 and FITC-CD25, then the changes of Treg (CD4+CD25+) in different groups were checked by flow cytometry; all data were statistically analyzed by the software of WinMDI 2.9, SPSS 11.5, Origin 7.5 and Matlab 2-D and 3-D plot function.

RESULTSThe levels of corticosterone were significantly higher in stress groups than that in corresponding control groups (P less than 0.05), especially in CRH+/+ stress group (P less than 0.01). However, the changes of Tregs were not obvious between stress groups and control groups with respective genotypes (P less than 0.05). Compared with that in CRH+/+ control group, the ratio of Treg and the expression of IL-17A in CRH-/- stress group were significantly higher than those in control group (P less than 0.05). Combined with the expression levels of corticosterone, Treg and Th17, our study suggests that endogenous glucocorticoid with basal level may cause the changes in Treg-Th17 balance. Moreover, as the corticosterone level increases, the expression of Treg and Th17 appears to manifest antagonistic fluctuant status with a rising tendency in general.

CONCLUSIONEndogenous glucocorticoid under early stage of stress may increase the function of T lymphocyte immunity to some extent.

Animals ; CD4 Antigens ; metabolism ; Corticosterone ; blood ; Corticotropin-Releasing Hormone ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Interleukin-17 ; metabolism ; Interleukin-2 Receptor alpha Subunit ; metabolism ; Lymph Nodes ; cytology ; Mice ; Mice, Knockout ; Pituitary-Adrenal System ; metabolism ; Running ; physiology ; Spleen ; cytology ; Stress, Physiological ; Th17 Cells ; metabolism

PURPOSE: Cortisol awakening response (CAR) and nighttime cortisol levels have been used as indices of adrenocortical activity. However, population-based statistical information regarding these indices has not been provided in healthy subjects. This study was carried out to provide basic statistical information regarding these indices. MATERIALS AND METHODS: Cortisol levels were measured in saliva samples collected immediately upon awakening (0 min), 30 min after awakening and in the nighttime on two consecutive days in 133 healthy subjects. RESULTS: We determined the mean [standard deviation (SD)], median (interquartile range) and 5th-95th percentile range for each measure and auxiliary indices for CAR, i.e., the secreted cortisol concentration within 30 min of awakening (CARscc) and absolute and relative increases in cortisol level within 30 min of awakening (CARi and CARi%, respectively). We also determined these values for auxiliary indices derived from nighttime cortisol level, i.e., the ratio of cortisol level 30 min after awakening (CA30 min) to nighttime level (CA30 min/NC), as well as absolute and relative decreases in cortisol levels from CA30 min to nighttime (DCd and DCd%, respectively). We found no significant differences in cortisol level for any time point or in auxiliary indices between collection days, genders and ages. CONCLUSION: The provided descriptive information and statistics on the CAR and nighttime cortisol level will be helpful to medical specialists and researchers involved in hypothalamus-pituitary-adrenal axis assessment.
Adult ; Circadian Rhythm ; Female ; Humans ; Hydrocortisone/*metabolism ; Hypothalamo-Hypophyseal System/physiology ; Male ; Middle Aged ; Pituitary-Adrenal System/physiology ; Republic of Korea ; Saliva/*metabolism ; Wakefulness

OBJECTIVETo study the effects of early enriched environment on behavioral development and serum corticosterone level in rats.

METHODSForty-five neonatal rats were randomly assigned into three groups：blank control, enriched environment and isolated environment. The open-field environment test and the Lat maze test were performed to assess anxiety/irritability-related behaviors of the rats on postnatal day 31. The level of serum corticosterone was measured by radioimmunology assay.

RESULTSThe level of serum corticosterone in the enriched environment group (8±3 ng/mL) was significantly lower than the blank control (11±4 ng/mL) and the isolated groups (22±4 ng/mL) (P<0.01). The open-field environment test showed that the numbers of passing panels, keeping an erect posture and grooming were less than those in the blank control and the isolated groups (P<0.05). According to the results of the Lat maze test, the frequencies of running across the corner, keeping an erect posture and leaning against the wall in the enriched environment group were less than those in the blank control and the isolated groups (P<0.05).

CONCLUSIONSEarly enriched environment can decrease serum corticosterone level and thus alleviates anxiety and irritability in rats. It may play an important role in the improvement of brain development.

Animals ; Behavior, Animal ; Brain ; growth & development ; Corticosterone ; blood ; Environment ; Female ; Hypothalamo-Hypophyseal System ; physiology ; Maze Learning ; Pituitary-Adrenal System ; physiology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the functional and ultramicrostructural effects of alpha lipoic acid on hypothalamus-pituitary-adrenal (HPA) axis in normal and diabetic rats.

METHODSUsing radioimmunoassay we observed the effects of three doses (1, 20, and 100 mg/kg) of alpha lipoic acid injected intraperitoneally for 3 weeks on the plasma levels of CRH, ACTH and COR in normal and diabetic rats. The ultramicrostructural changes of the hypophysis and pituitary gland after alpha lipoic acid treatment were observed under transmission electron microscope.

RESULTSCompared with the control group, CRH level in lipoicin-treated normal and diabetic rats was significantly reduced (P<0.05). ACTH level of the 3 lipoicin doses groups of normal rats decreased, and a significant reduction occurred in medium-dose lipoicin group of diabetic rats (P<0.05). COR level showed the same changes as CRH level in normal rats, but decreased significantly in high- and medium-dose lipoicin groups of diabetic rats. Lipoicin treatment produced no apparent effect on the ultramicrostructures of the hypophysis and pituitary gland cells, which were the targets of diabetic lesions with low metabolism functions. Lipoicin treatment obviously enhanced the hypophysis and pituitary gland cell metabolism function to resist diabetic oxidative stress.

CONCLUSIONLipoicin can inhibit the HPA axis directly or indirectly in normal and diabetic rats.

Animals ; Diabetes Mellitus, Experimental ; pathology ; physiopathology ; Hypothalamo-Hypophyseal System ; drug effects ; physiology ; ultrastructure ; Male ; Pituitary-Adrenal System ; diagnostic imaging ; drug effects ; physiology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Thioctic Acid ; pharmacology ; Ultrasonography

OBJECTIVETo study the changes of glucocorticoid receptor (GR) expression in embryonic rat cortical neurons exposed to transient Mg(2+)-free treatment.

METHODSSix days after rat cortical neuronal cultures, two groups were created based on the medium to which were transiently exposed. The control group was exposed to a physiological solution (PS), and the Mg(2+)-free group was exposed to the same medium as the control group except for the removal of magnesium. The expression of GR mRNA and protein was determined by real-time PCR and immunocytochemistry staining 1, 7 and 12 days after transient Mg(2+)-free treatment.

RESULTSCompared to the control group, the Mg(2+)-free group displayed the significantly less accumulated optical density (AOD) of GR immunoreactivity 12 days after transient Mg(2+)-free treatment (p<0.05). On the contrary, GR mRNA expression increased significantly 1 and 7 days after transient Mg(2+)-free treatment in the Mg(2+)-free group (p<0.05).

CONCLUSIONSGR expression is modified following Mg-free-induced injury in cultured developing neurons in rats.

Animals ; Cell Survival ; Cells, Cultured ; Cerebral Cortex ; metabolism ; Fetus ; metabolism ; Hypothalamo-Hypophyseal System ; physiology ; Magnesium ; physiology ; Neurons ; metabolism ; Pituitary-Adrenal System ; physiology ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Receptors, Glucocorticoid ; analysis ; genetics