OBJECTIVETo establish social stress induced depression-like model in mice of C57BL/6 strain, and to assess its reliability using differenf behavioral methods.

METHODSTotally 20 male mice of C57BL/6 strain were divided into the normal group and the stress model group by random digit table,10 in each group. Another 10 CD1 mice were subjected to social stress. Mice in the normal control group received no stress, while those in the model group received social stress for 10 successive days. Behavioral assessment was performed using social interaction test (SIT), the elevated plus-maze (EPM) test, tail suspension test (TST), respectively. Serum cortisol level was detected by ELISA to assess the reliability of the model.

RESULTSIn the social interaction test when the social target (CDI mice) was inexistent, mice in the normal control group spent longer time in the social interaction zone and less time in the corner zone (P < 0.05); mice in the model group spent less time in the social interaction zone and more time in the corner zone (P < 0.05). Compared with the normal group when CDI mice existed, mice in the model group spent less time in the social interaction zone and more time in the corner zone (P < 0.05). Compared with the normal control group, the total times for entry into open arms, close arms, and the maze were obviously reduced (P < 0.05), and the proportion of entering open arms was significantly reduced (P < 0.05) in the model group. In TST, the motionless time within the last 4 mm was prolonged in the model group (P < 0.05). The serum cortisol level in the model group was obviously elevated (P < 0.01).

CONCLUSIONSocial stress induced depression-like animal model in mice of C57BL/6 straineasquite reliable and possibly suitable to be used in integrative medicine research of combination of disease and syndrome model.

Animals ; Behavior, Animal ; Depression ; physiopathology ; Disease Models, Animal ; Hydrocortisone ; blood ; Male ; Mice ; Mice, Inbred C57BL ; Social Behavior ; Stress, Psychological

BACKGROUNDThe prevalence reported of maternal depression from the first to the third trimester was 7.4%, 12.8%, 12.0% respectively, which implies that around one-tenth of pregnant women suffer from psychological disorder during the whole pregnancy. It is assumed that during pregnancy the maternal-fetal circulation unit is also affected by maternal psychological status. The aim of this study is to explore the association between maternal psychological status and fetal dynamic blood flow circulation during pregnancy.

METHODSWe recruited 102 singleton low risk pregnant women between 30 to 33 gestational weeks. The Symptom Checklist-90 (SCL-90) was used to assess maternal psychological status. Ultrasound Doppler was used to measure blood flow changes in maternal-fetal circulation. Pulsatility index (PI) value was measured in umbilical artery (UA), fetal middle cerebral artery (MCA) and maternal uterine arteries (UTA). Peak systolic velocity (PSV) was measured in MCA and velocity was measured in umbilical vein (UV). Statistical analysis was performed with standard nonparametric Mann-Whitney U tests. Two-tailed P values <0.05 were considered statistical significance.

RESULTSOf the 102 pregnant women, 12 patients show high levels of poor mental health. Women with poor mental health have higher umbilical artery PI values than good mental health patients (P = 0.020). A higher MCA PI value is found in poor mental health patients but this does not reach statistical significance (P = 0.053). Women with hostility show lower placental scores (P = 0.030). Women with somatization demonstrate higher values in UA PI, MCA PI and MCA PSV (P = 0.049, 0.030 and 0.035 respectively). A higher MCA PSV value is also found in phobic anxiety patients (P = 0.046).

CONCLUSIONSPoor mental health during pregnancy is found to have an adverse effect on maternal-fetal circulation. Umbilical artery and fetal cerebral circulation are more sensitive and affected by maternal psychological disorder.

Adult ; Blood Flow Velocity ; physiology ; Female ; Fetus ; blood supply ; physiology ; Gestational Age ; Hemodynamics ; physiology ; Humans ; Pregnancy ; Pregnancy Trimester, Third ; Stress, Psychological ; physiopathology

This study is to investigate the amelioration effect of glucocorticoid receptor (GR) antagonist mifepristone on the changes of learning and memory abilities in rat model of depression. In the present study, a 35-day rat chronic unpredictable stress (CUS) model was used to observe both depression-like behaviors with sucrose preference test and open-field test and learning and memory-associated behaviors with Morris water maze test. A total of 45 male adult Sprague-Dawley rats were randomly assigned to three groups of equal size: control group (CON); CUS group (CUS); CUS + mifepristone group (CM). Animals in CM group were first exposed to CUS for 14 days, and then were administered with 50 mg x kg(-1) x d(-1) of mifepristone with continued CUS procedure. Corticosterone EIA Kit was used to detect the concentration of plasma corticosterone (CORT). Nissl staining was used to observe the structure of hippocampus. The results demonstrated that CUS exposure induced both depressive-like and learning and memory-associated behaviors and these deficits were reversed by mifepristone. Compared to CON group, the concentration of plasma CORT increased significantly in CUS group. CUS exposure damaged the structure of hippocampus, whereas mifepristone had an amelioration effect. Together, the structural deficits of hippocampus resulting from long-term stress exposure, which could contribute to the impairment of learning and memory in depression, are reversed by the GR receptor antagonist mifepristone.
Animals ; Behavior, Animal ; drug effects ; Corticosterone ; blood ; Depression ; blood ; etiology ; pathology ; physiopathology ; Hippocampus ; pathology ; Learning ; drug effects ; Male ; Memory ; drug effects ; Mifepristone ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Glucocorticoid ; antagonists & inhibitors ; Stress, Psychological ; complications

OBJECTIVETo observe the effect of hesperidin on behavior and hypothalamic-pituitary-adrenal (HPA) axis of ratmodel of chronic stress-induced depression.

METHODChronic unpredictable mild stress (CUMS) was used to establish the rat depression model. Sixty male SD rats were divided randomly into six groups: the normal group, the model group, the hesperidin (40, 80, 160 mg x kg(-1)) group and the positive fluoxetine (10 mg x kg(-1)) group. They were orally administered with drugs for three weeks. The sucrose preference test and the forced swimming test (FST) were assayed to detect animal behavior. The levels of corticosterone (CORT) in serum, mRNA of corticotropin release factor (CRF) in hypothalamus as well as protein expression of glucocorticoid receptor (GR) in paraventricular nucleus (PVN) were determined to clarify the anti-depression effect and mechanism of hesperidin.

RESULTCompared with the model group, rats in the hesperidin (40, 80, 160 mg x kg(-1)) treatment group showed significant increase in the sucrose consumption and decrease in the immobility time in FST to varying degrees. Meanwhile, the excessively high serum CORT and adrenal index of CUMS rats were reversed by treatment with hesperidin. In addition, hesperidin inhibited CRF mRNA expression in hypothalamus and up-regulated GR protein expression in PVN among CUMS rats.

CONCLUSIONHesperidin could effectively improve the behavior of CUMS rats and show the anti-depression effect. Its mechanisms may be related to the function of regulating HPA axis.

Administration, Oral ; Animals ; Behavior, Animal ; drug effects ; Corticosterone ; blood ; Corticotropin-Releasing Hormone ; genetics ; metabolism ; Depression ; drug therapy ; etiology ; Fluoxetine ; administration & dosage ; Gene Expression Regulation ; drug effects ; Hesperidin ; administration & dosage ; pharmacology ; Hypothalamo-Hypophyseal System ; drug effects ; physiopathology ; Hypothalamus ; metabolism ; Male ; Models, Animal ; Pituitary-Adrenal System ; drug effects ; physiopathology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Glucocorticoid ; metabolism ; Stress, Psychological ; complications ; drug therapy ; Sucrose ; metabolism ; Swimming ; Up-Regulation

OBJECTIVETo observe the effect of chronic psychological stress on vascular endothelial dysfunction rats and to explore the intervention and mechanism of Tongxinluo (TXL) on it.

METHODSForty male Wistar rats were randomly divided into the normal control group (with no modeling), the endothelial dysfunction group (the HCY group), the psychological stress group (the model group), and TXL group, ten in each group. Rats in the latter three groups were fed with 3% high methionine diet to duplicate vascular endothelial dysfunction (VED) model. In addition, chronic psychological stress was applied in VED rats using repeated binding method. TXL at the dose of 1.2 g/kg body weight was given by gastrogavage. The plasma endothelin (ET) and angiotensin II (Ang II), serum cortisone (CORT) were detected by radioimmunoassay. The serum nitric oxide (NO) was detected by nitrate reductase. Ultrastructural changes of aortic endothelial cells were observed by transmission electron microscope. Serum levels of norepinephrine (NE) and epinephrine (E) were detected by enzyme linked immunosorbent assay (ELISA).

RESULTSCompared with the plasma ET level and the serum NO level in the HCY group (161.70 +/- 13.96 pg/mL and 26.82 +/- 13.03 micromol/L), the plasma ET level obviously increased (178.25 +/- 21.85 pg/mL) (P < 0.05) and the serum NO level decreased (24.91 +/- 9.95 micromol/L, P > 0.05), levels of CORT, NE, and E obviously increased in the model group (all P < 0.05). Ultrastructural changes of aortic endothelial cells were obviously injured. Compared with the model group, the plasma ET level (154.74 +/- 13.27 pg/mL), Ang II, CORT, NE, and E obviously decreased (P < 0.05, P < 0.01), the serum NO level obviously increased (34.44 +/- 18.35 micromol/L, P < 0.05). Ultrastructural changes of aortic endothelial cells were obviously improved.

CONCLUSIONSChronic psychological stress could obviously aggravate endothelial injury in VED rats. TXL showed protection on the vascular endothelial structure and function.

Animals ; Drugs, Chinese Herbal ; therapeutic use ; Endothelin-1 ; blood ; Endothelium, Vascular ; drug effects ; physiopathology ; Male ; Nitric Oxide ; blood ; Rats ; Rats, Wistar ; Stress, Psychological ; drug therapy

Corticotrophin-releasing factor (CRF) plays a major role in coordinating stress responses. We aimed to test whether blocking endogenous CRF activity can prevent the stress-induced dilation of intercellular spaces in esophageal mucosa. Eighteen adult male rats were divided into 3 groups: 1) a non-stressed group (the non-stressed group), 2) a saline-pretreated stressed group (the stressed group), 3) and an astressin-pretreated stressed group (the astressin group). Immediately after completing the experiments according to the protocol, distal esophageal segments were obtained. Intercellular space diameters of esophageal mucosa were measured by transmission electron microscopy. Blood was sampled for the measurement of plasma cortisol levels. Mucosal intercellular spaces were significantly greater in the stressed group than in the non-stressed group. Mucosal intercellular spaces of the astressin group were significantly smaller than those of the stressed group. Plasma cortisol levels in the stressed group were significantly higher than in the non-stressed group. Pretreatment with astressin tended to decrease plasma cortisol levels. Acute stress in rats enlarges esophageal intercellular spaces, and this stress-induced alteration appears to be mediated by CRF. Our results suggest that CRF may play a role in the pathophysiology of reflux-induced symptoms or mucosal damage.
Animals ; Corticotropin-Releasing Hormone/*antagonists & inhibitors/metabolism/pharmacology ; Esophagus/anatomy & histology/*drug effects ; Extracellular Space/*drug effects ; Hydrocortisone/blood ; Male ; Mucous Membrane/anatomy & histology/*drug effects ; Neuroprotective Agents/pharmacology ; Peptide Fragments/*pharmacology ; Rats ; Rats, Wistar ; *Stress, Psychological/blood/physiopathology

OBJECTIVETo study the changes of rat red blood cells on T, B lymphocytes proliferation in chronic unpredictable mild stress (CUMS).

METHODSThirty Wistar rats were averagely divided into control group and the CUMS group. The relevant behavioral performance and red blood cells on lymphocytes proliferation Changes by MTT colorimetric were observed.

RESULTSAfter fourteen days, the growth of weight and organic coefficient of brain decreased in model group (P < 0.05), with a significantly reduced consumption and preference of sucrose solutions, and increased pure water consumption as compared with control group (P < 0.05). Plasma corticosterone levels peaked at seven days but on a declining trend after fourteen days. The rate of red blood cells on T, B lymphocyte proliferation in depression group was lower than non-stress in 7, 14, 21 days (P < 0.05).

CONCLUSIONThe repeated chronic mild stress stimulation can induce long-time changes in acts and activities and decrease the rate of red blood cells on T, B lymphocytes proliferation, which can provide a new experimental method to observe the red blood cell immune function under the stress.

Animals ; Cell Proliferation ; Depression ; blood ; etiology ; Disease Models, Animal ; Erythrocytes ; cytology ; Lymphocyte Activation ; Lymphocytes ; cytology ; Male ; Rats ; Rats, Wistar ; Stress, Psychological ; physiopathology

AIMTo explore the effects of different doses of tyrosine modulation on behavioral performances in open field test of psychological stress rats.

METHODSThe animal model of psychological stress was developed by restraint stress for 21 days. Wistar rats were randomly assigned to five groups (n = 10) as follows: control group (CT), stress control group (SCT), low, medium and high-doses of tyrosine modulation stress groups (SLT, SMT and SIT). The changes of behavioral performances were examined by open-field test. Serum levels of cortisol, norepinephrine and dopamine were also detected.

RESULTSThe levels of serum cortisol were all increased obviously in the four stress groups, and their bodyweight gainings were diminished. The behavioral performances of SCT rats in open-field test were changed significantly in contrast to that of CT rats. However, The behavioral performances of SMT and SHT rats were not different from that of CT rats. In addition, the serum levels of norepinephrine and dopamine were downregulated obviously in SCT and SLT groups, and no differences were observed in other groups.

CONCLUSIONPsychological stress can impair body behavioral performances, and moderate tyrosine modulation may improve these abnormal changes. The related mechanisms may be involved with the changes of norepinephrine and dopamine.

Animals ; Behavior, Animal ; drug effects ; Dopamine ; blood ; Male ; Norepinephrine ; blood ; Random Allocation ; Rats ; Rats, Wistar ; Restraint, Physical ; psychology ; Stress, Psychological ; drug therapy ; physiopathology ; Tyrosine ; therapeutic use

In order to explore the influence of psychological stress on the reproductive axis, we started with the original data of biology from animal experiments, then we conducted the factor analysis of 6 important bio-regulatory factors and established the Factor Analysis Model for the endocrine network of reproduction axis under psychological stress. Based on the biological data obtained from animal experiments, it is found that, compared with the relationship seen in the factor analysis model in normal condition, the relationship among the biological factors is more complicated. The key factor, GnRH, has lost its strong regulating action on the subordinate factors, especially on E2; on the other hand, beta-EP has very strong regulating action on E2, and E2 is controlled mainly by beta-EP.
Animals ; Estradiol ; blood ; physiology ; Female ; Follicle Stimulating Hormone ; blood ; physiology ; Gonadotropin-Releasing Hormone ; blood ; physiology ; Models, Biological ; Neurosecretory Systems ; physiology ; Rats ; Reproduction ; physiology ; Stress, Psychological ; metabolism ; physiopathology ; beta-Endorphin ; blood ; physiology

OBJECTIVETo study the effects of experimental navigation and deuteroexhaustive exercise on the serum levels of testosterone (T), corticosterone (CORT), luteinizing hormone (LH) and follicle stimulating hormone (FSH).

METHODSThirty-six male SD rats were randomly divided into an experimental navigation group (Group A), which underwent 180 min wearing floating with psychological stress, a deuteroexhaustive exercise group (Group B), which were subjected to 120 min intensive running on the treadmill after the accomplishment of the same procedure as Group A, and a control group (Group C). Blood samples were obtained at the end of the experiment to determine the T, CORT, LH and FSH of the rats.

RESULTSCompared with Group C, serum T was statistically decreased in Group A and B (P < 0.05), while CORT was increased slightly in Group A and significantly in Group B (P < 0.05). A statistically lower level of serum LH was observed in Group B (P < 0.05), but no significant differences were found in serum FSH among the three groups.

CONCLUSIONStresses of experimental navigation and intensive exercise suppress the function of the hypothalamic-pituitary-testicle axis in rats.

Animals ; Corticosterone ; blood ; Follicle Stimulating Hormone ; blood ; Hypothalamo-Hypophyseal System ; physiology ; Luteinizing Hormone ; blood ; Male ; Physical Conditioning, Animal ; physiology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Stress, Psychological ; blood ; physiopathology ; Testis ; physiology ; Testosterone ; blood