AIMTo analyse the mechanism of corticosterone on the elevation of cytosolic free calcium ([Ca2+]i) induced by high-K+ in pheochromocytoma PC12 cells,

METHODSThe [Ca2+]i was real-time checked by fluorescence image system.

RESULTS(1) When the cells were preincubated at 37 degrees C for 5 min in the presence of various concentration corticosterone and stimulated with 55 mmol/L KCl , an inhibitory effect of corticosterone on delta[Ca2+]i was observed in a concentration-dependent manner. (2) When PC12 cells were preincubated with various concentration of B-BSA at 37 degrees C for 5 min and stimulated with 55 mmol/L KCl, an inhibitory effect of B-BSA on delta[Ca2+]i was observed, which is also concentration-dependent manner. (3) The inhibitory effect of corticosterone and B-BSA could not be antagonized by RU38486 at 10(-4) mol/L. (4) cycloheximide could not block the inhibitory effect of corticosterone after pretreating cells at 10(-5) mol/L at 37 degrees C for 3 hours.

CONCLUSIONIt is obvious that the locus of corticosterone action is on the plasmic membrane. The inhibitory effect of corticosterone is independent of protein synthesis and intracellular glucocorticoid receptor. The effect of corticosterone on [Ca2+]i is nongenomic action in PC12 cells.

Animals ; Calcium ; metabolism ; Corticosterone ; pharmacology ; PC12 Cells ; drug effects ; Potassium ; pharmacology ; Rats

Objective: A gradient stress model of PC12 cells induced by corticosterone was established to provide a basis for the evaluation and regulation of cell stress. Methods: The effect of corticosterone on cell viability was observed by measuring PC12 cell viability at different concentrations of corticosterone (0~1 000 μmol/L) after different intervention times (8~48 h) to screen the cell models for optimal intervention conditions. Key stress indicators (MDA, SOD, NADH, LDH) were measured spectrophotometrically and microscopically to evaluate the models. Results: When the concentration of corticosterone was below 200 μmol/L and the intervention time was 12 h, the cell viability was below half inactivation rate, which could reduce the confounding factors due to the decrease of cell viability in each group. Compared with the blank control group, corticosterone increased the levels of MDA, NADH and LDH,and decreased the levels of SOD in the model group in a concentration-dependent manner (P＜0.01), which was consistent with the construction of the gradient stress model. Conclusion: A gradient stress injury model of PC12 cells was successfully established, with intervention concentrations of 0 μmol/L, 25 μmol/L, 50 μmol/L, 100 μmol/L, 150 μmol/L and 200 μmol/L corticosterone at an intervention time of 12 h. The degree of stress injury of the cell model was increased gradually, which could be used as a basis and object for conducting cell stress injury assessment and regulation experiments.
Animals ; Cell Survival ; Corticosterone/pharmacology* ; NAD/pharmacology* ; PC12 Cells ; Rats ; Superoxide Dismutase

OBJECTIVE: Although the protective effects of Momordica charantia L. (MC) extract on chemical-induced testicular damage have been studied, the preventive effects of MC extract on functional proteins in the epididymis under chronic stress have never been reported. This study investigated the protective effects of MC fruit extract on protein secretion, especially tyrosine-phosphorylated proteins, in the epididymis of rats exposed to chronic unpredictable stress (CUS). METHODS: Total phenolic compounds (TPC), total flavonoid compounds (TFC) and antioxidant capacities of MC extract were measured. Adult male rats were divided into 4 groups: control group, CUS group, and 2 groups of CUS that received different doses of MC extract (40 or 80 mg/kg). In treated groups, rats were given MC daily, followed by induction of CUS (1 stressor was randomly applied from a battery of 9 potential stressors) for 60 consecutive days. Plasma corticosterone and testosterone levels were analyzed after the end of experiment. Expressions of heat-shock protein 70 (HSP-70) and tyrosine-phosphorylated proteins present in the fluid of the head and tail of the epididymis were quantified using Western blot. RESULTS: MC extract contained TPC of (19.005 ± 0.270) mg gallic acid equivalents and TFC of (0.306 ± 0.012) mg catechin equivalents per gram, and had 2,2-diphenyl-1-picrylhydrazyl antioxidant capacity of (4.985 ± 0.086) mg trolox equivalents per gram, radical 50% inhibitory concentration of (2.011 ± 0.008) mg/mL and ferric reducing antioxidant power of (23.697 ± 0.819) µmol Fe(II) per gram. Testosterone level in the epididymis was significantly increased, while the corticosterone level was significantly improved in groups treated with MC extract, compared to the CUS animals. Particularly, an 80 mg/kg dose of MC extract prevented the impairments of HSP-70 and tyrosine-phosphorylated protein expressions in the luminal fluid of the epididymis of CUS rats. CONCLUSION MC fruit extract had antioxidant activities and improved the functional proteins secreted from the head and tail of the epididymis. It is possible to develop the MC fruit extract as a male fertility supplement for enhancing functional sperm maturation in stressed men.
Male ; Rats ; Animals ; Antioxidants/pharmacology* ; Tyrosine/metabolism* ; Plant Extracts/therapeutic use* ; Corticosterone ; Seeds ; Testosterone ; Fruit/metabolism*

Objective: To understand the improvement effect of Lycium barbarum polysaccharide (LBP) on the intestinal flora of mother mice during pregnancy and their offspring who experienced chronic stress, and provide new ideas for improving the effect of stress on the intestinal tract. Methods: From July to October 2019, 24 SPF-grade female SD rats were selected and divided into control group, stress group, and stress+LBP group, with 8 rats in each group. A chronic unpredictable mild stimulation model during pregnancy was established (21 days) , and 40 mg/kg LBP solution was administered by gavage on the 8th day of stress. Venous blood from the medial canthus of the female mice was collected on the 1st day before stress and on the 1st, 7th, 14th and 21st days, respectively. Cortisol was measured and corticosterone concentration was calculated. The fresh feces of famale mice after stress and 20-day postnatal offspring mice were collected, and Illumina Miseq sequencing technology, alpha diversity and community composition were used to analyze the diversity and structure of intestinal flora. Results: On the 7th and 14th days of stress, the plasma corticosterone concentration of female mice in the stress group and stress+LBP group was higher than that in the control group (P<0.05) . In the Alpha diversity of female mice, the Ace index of the stress group was lower than that of the control group (P<0.05) . The analysis of intestinal flora structure showed that at the species level, the proportions of Lachnospiraceae and Lactobacillus in the stress+LBP group were higher than those in the stress group and control group. At the order level, the proportion of Clostridiales in the stress+LBP group was higher than that in the stress group and lower than that in the control group, while the proportion of Lactobacillales was higher than that in the stress group and control group. In the Alpha diversity of the offspring group, the Shannon index, Ace index and Chao index of the stress+LBP offspring group were higher than those of the stress offspring group (P<0.05) . The proportion of Lactobacillus in the stress+LBP offspring group was higher than that in the control offspring group and stress offspring group, and the proportions of Lachnospiraceae and Ruminococcaceae in the stress+LBP offspring group were higher than those in the stress offspring group, the proportion of Bacteroidales in the stress+LBP offspring group was lower than that in the stress offspring group, and the proportion of Clostridiales in the stress+LBP offspring group was higher than that in the stress and control offspring groups. Conclusion: The intervention of LBP may improve the changes in the intestinal flora diversity, abundance and flora structure of mother mice and offspring caused by pregnancy stress, thereby maintaining the balance of intestinal flora.
Animals ; Corticosterone ; Drugs, Chinese Herbal/pharmacology* ; Female ; Gastrointestinal Microbiome ; Hydrocortisone ; Mice ; Pregnancy ; Rats ; Rats, Sprague-Dawley

BACKGROUNDThe immunomodulatory effects of glucocorticoids (GCs) have been described as bimodal. High concentration of GCs exerts immunosuppressive effects and low levels of GCs are immunopermissive. While the immunosuppressive mechanisms of GCs have been investigated intensely, the immunopermissive effects of GCs remain unclear. A lot of studies showed GCs could exert rapid non-genomic actions. We herein studied the rapid immunopromoting effects of GCs.

METHODSWe observed the rapid (within 30 minutes) effects of corticosterone on respiratory burst of mouse peritoneal macrophages and studied their mechanisms. The superoxide anions were measured by cytochrome C reduction assay. Protein kinase C phosphorylation was measured by Western blotting and membrane fluidity was evaluated by fluorescence polarization measurement.

RESULTSThe 10(-8) mol/L and 10(-7) mol/L corticosterone rapidly increased the superoxide anions production by macrophages, which were insensitive to GC-receptor antagonist, mifepristone, and protein-synthesis inhibitor, cycloheximide. Corticosterone coupled to bovine serum albumin was able to mimic the effects of corticosterone. The effects were independent of protein kinase C pathway and the change in membrane fluidity.

CONCLUSIONSThe results indicate that corticosterone rapidly promote the superoxide anions production by mouse peritoneal macrophages may through non-genomic mechanisms. This study may contribute to understanding the effects of GCs under stress condition and the physiological significance of nongenomic effects of GCs.

Animals ; Corticosterone ; pharmacology ; Macrophages, Peritoneal ; drug effects ; physiology ; Male ; Mice ; Mice, Inbred BALB C ; Respiratory Burst ; drug effects ; Superoxides ; metabolism

Animals ; Corticosterone ; pharmacology ; Hippocampus ; drug effects ; physiology ; In Vitro Techniques ; Long-Term Potentiation ; drug effects ; physiology ; Male ; Rats ; Rats, Wistar

OBJECTIVETo observe the effects of signal factors of corticosterone (CS), cAMP, cGMP, Ca2+ andprotein kinase C (PKC) on lymphocyte apoptosis in mouse thymus induced by X-rays of 4 Gy in vitro.

METHODSThe DNA lytic rate for thymocytes was measured by fluorospectrophotometry.

RESULTSThe DNA lyric rate for thymocytes 4-8 hours after irradiation with 2-8 Gy was significantly higher than that in the control (P<0.01). As compared with the control, the DNA lytic rate for thymocytes treated with 0.01 micromol/L CS (P<0.01), 50 ng/mL cAMP (P<0.01), 0.05-0.4 microg/mL ionomycin (Iono, P<0.05 or P<0.01) or 0.05-0.4 ng/mL phorbol myristate acetate (PMA, P<0.05 or P<0.01), respectively, was significantly increased, while the rate for thymocytes treated with 50 ng/mL cGMP was not significantly increased. The DNA lytic rate for thymocytes treated with 0.01 micromol/L CS (P<0.01), 50 ng/mL cAMP (P<0.01), 0.2 and 0.4 microg/mL Iono (P<0.05), and 0.2 and 0.4 ng/mL PMA (P<0.05) plus 4-Gy irradiation, respectively, was significantly higher than that treated with single 4-Gy irradiation, while the rate for thymocytes treated with 50 ng/mL cGMP plus 4-Gy irradiation was not increased. When both 0.4 microg/mL Iono and 0.4 ng/mL PMA acted on the thymocytes, the DNA lytic rate for thymocytes was significantly higher than that in the control (P<0.01), the DNA lytic rate for thymocytes treated with both 0.4 microg/mL Iono and 0.4 ng/mL PMA plus 4-Gy irradiation was significantly higher than that treated with single 4-Gy irradiation (P<0.05), but was not significantly higher than that treated with 0.4 microg/mL Iono plus 4-Gy irradiation or 0.4 ng/mL PMA plus 4-Gy irradiation.

CONCLUSIONCS, cAMP, Ca2+, and PKC signal factors can promote thymocyte apoptosis induced by larger dose X-rays.

Animals ; Apoptosis ; drug effects ; radiation effects ; Calcium ; pharmacology ; Corticosterone ; pharmacology ; Cyclic AMP ; pharmacology ; Cyclic GMP ; pharmacology ; Ionomycin ; pharmacology ; Male ; Mice ; Protein Kinase C ; metabolism ; Spectrometry, Fluorescence ; Tetradecanoylphorbol Acetate ; pharmacology ; Thymus Gland ; cytology ; drug effects ; X-Rays

Ginseng is a typical adaptogen which has resistance to various stresses. This effect is related to the hypothalamic-pituitary-adrenal (HPA) axis. As the main active ingredients, saponin has the similar structure to steroids. The regulation characteristics of ginseng saponin on the HPA axis are narrated from the aspects of total saponin and saponin monomers in this paper after the introduction of adaptation definition and HPA axis regulation mechanisms. Pharmacological effects of ginseng saponin and the regulation effect of HPA axis are summarized finally.
Adaptation, Physiological ; Adrenocorticotropic Hormone ; secretion ; Animals ; Corticosterone ; secretion ; Ginsenosides ; isolation & purification ; pharmacology ; Humans ; Hypothalamo-Hypophyseal System ; drug effects ; secretion ; Panax ; chemistry ; Pituitary-Adrenal System ; drug effects ; secretion

OBJECTIVETo study the effect of osthole (Ost) on adrenocortical function in Y1 mouse adrenocortical tumor cells.

METHODSY1 mouse adrenocortical tumor cells were taken as subjects in this experiment. In 10.0%, 1.0%, and 0.1% serum DMEM-F12 medium, Y1 cells were treated with 1, 10, 25, 50, 100, and 200 micromol/L Ost for 24 and 48 h. 0.1% Dimethyl Sulfoxide (DMSO) was taken as negative control group and 1 mmol/L (Bu) 2cAMP as positive control group. Cell growth morphology was observed under inverted microscope. Contents of corticosterone were tested by ELISA. Expression levels of steroids synthase such as Star, Cyp11a1, Cyp21a1, Hsd3b2, Cyp11b1, Cyp11b2, Cyp17a1, and Hsd17b3 mRNA were detected by Real time quantitative PCR (RT-qPCR).

RESULTSY1 cell proliferation was obviously inhibited by 100 and 200 micromol/L Ost, and its inhibitory effect was more significant in 0.1% serum medium. Compared with the negative control group, gene expressions of Star, Cyp11a1 , Cyp21a1, Hsd3b2, Cyp11b1, Cyp17a1, and Hsd17b3 were significantly enhanced in the posi- tive control group (P < 0.05). Y1 cell corticosterone levels significantly increased in 50 micromol/L Ost treatment group after 24-and 48-h intervention (P < 0.05). Contents of corticosterone increased more obviously in 25 and 50 +/- mol/L Ost treatment groups after 48-h intervention, as compared with 24-h intervention (P < 0.01). After 24-h intervention, expression levels of Star, Cyp21a1, and Hsd3b2 genes were significantly up-regulated in 25 and 50 lLmol/L Ost groups (P < 0.05). Star gene expression was further enhanced after 48-h intervention (P < 0.05). However, Ost showed no effect on Cyp11a1 (P > 0.05). Additionally, gene expressions of Cyp11b1 and Cyp17a1 were significantly enhanced by 10, 25, and 50 pLmolIL Ost after treatment for 24 and 48 h (P < 0.05). Ost showed no obvious effect on Cyp11b2 and Hsd17b3 expressions.

CONCLUSIONOst could regulate adrenal cortex function and promote corticosterone synthesis and secretion through strengthening gene expressions of steroidogenic enzymes.

Adrenal Cortex ; drug effects ; Adrenal Cortex Neoplasms ; pathology ; Animals ; Corticosterone ; biosynthesis ; Coumarins ; pharmacology ; Gene Expression ; Mice ; RNA, Messenger ; metabolism ; Tumor Cells, Cultured

AIMThe effect of stress hormone corticosterone on hippocampal neurons delayed rectified potassium currents was probed.

METHODSThe potassium currents of rat hippocampal neurons in primary culture were measured with patch clamp whole-cell recording.

RESULTSIt showed that the amplitudes of the potassium currents in hippocampal neurons decreased. However, the threshold potential of potassium currents increased.

CONCLUSIONIt is speculated that excessive corticosterone may hurt the hippocampal neurons via its effects on the potassium currents of rat hippocampal cells.

Animals ; Animals, Newborn ; Cells, Cultured ; Corticosterone ; pharmacology ; Delayed Rectifier Potassium Channels ; drug effects ; Hippocampus ; cytology ; drug effects ; Neurons ; drug effects ; physiology ; Patch-Clamp Techniques ; Rats ; Rats, Wistar