scholarly journals Maintenance of Gonadotropin Secretion by Glucocorticoids under Stress Conditions through the Inhibition of Prostaglandin Synthesis in the Brain

Endocrinology ◽  
2006 ◽  
Vol 147 (3) ◽  
pp. 1087-1093 ◽  
Author(s):  
Takashi Matsuwaki ◽  
Yuko Kayasuga ◽  
Keitaro Yamanouchi ◽  
Masugi Nishihara
Keyword(s):  
Restraint Stress ◽  
Acute Stress ◽  
Reproductive Function ◽  
Stress Conditions ◽  
Ovariectomized Rats ◽  
Gonadotropin Secretion ◽  
Inhibition Of Prostaglandin Synthesis ◽  
Corticosterone Treatment ◽  
Factor Α ◽  
The Brain

We have previously reported that glucocorticoids counteract the suppressive effects of tumor necrosis factor-α on both pulsatile and surge secretion of LH. This suggests that glucocorticoids have a protective effect on reproductive function under infectious stress. In the present study, we examined whether glucocorticoids maintain pulsatile LH secretion under various conditions of acute stress and the possible involvement of prostaglandins (PGs) in glucocorticoid actions. Three different types of stressors, namely infectious (lipopolysaccharide, 0.5 μg/kg), hypoglycemic (2-deoxy-d-glucose, 100 mg/kg), and restraint stress (1 h) were applied to ovariectomized rats. In ovariectomized rats, LH pulses were partially suppressed by restraint, but not by lipopolysaccharide or 2-deoxy-d-glucose. On the other hand, adrenalectomy (ADX) significantly enhanced the suppressive effects of all the stressors applied on LH pulses. Treatment with both corticosterone (25 mg/kg) and indomethacin (10 mg/kg) in ADX rats significantly attenuated the suppressive effects of these stressors on LH pulses. In addition, the immunoreactivity of cyclooxygenase-2, a PG-synthesizing enzyme, in the brain under stress conditions was much enhanced by ADX, and this was counteracted by corticosterone treatment. Similarly, an increase in body temperature under restraint stress was enhanced by ADX and suppressed by corticosterone. These results suggest that suppression of LH pulsatility by stress is mediated by PGs in the brain, and that increased release of endogenous glucocorticoids in response to stress counteracts this suppression by inhibiting PG synthesis, and thereby maintains reproductive function regardless of the nature of the stressor.

scholarly journals Divergent Roles of the CRH Receptors in the Control of Gonadotropin Secretion Induced by Acute Restraint Stress at Proestrus

Endocrinology ◽  
2012 ◽  
Vol 153 (10) ◽  
pp. 4838-4848 ◽  
Author(s):  
Guillermo A. Ariza Traslaviña ◽  
Celso Rodrigues Franci
Keyword(s):  
Restraint Stress ◽  
Acute Stress ◽  
Reproductive Function ◽  
Brain Regions ◽  
Noradrenergic Neurons ◽  
Gonadotropin Secretion ◽  
Acute Restraint Stress ◽  
Lh Secretion ◽  
Crh Receptors ◽  
Stimulation Of

Abstract CRH has been implicated as a mediator of stress-induced effects on the hypothalamus-pituitary-gonad axis, acting via CRH receptors in various brain regions. We investigated whether the effects of restraint stress on the secretion of gonadotropins on the morning of proestrus are mediated by the CRH-R1 or CRH-R2 receptors in the oval subdivision of the anterolateral BST, the central amygdala, the locus coeruleus (LC), or the A1 and A2 neuron groups in the medulla. At proestrus morning, rats were injected with antalarmin (a CRH-R1 antagonist), asstressin2-B (a CRH-R2 antagonist) or vehicles. Thirty minutes after the injection, the animals were placed into restraints for 30 min, and blood was sampled for 2 h. At the end of the experiment, the brains were removed for immunofluorescence analyses. Restraint stress increased the levels of FSH and LH. Antalarmin blocked the stress-induced increases in FSH and LH secretion, but astressin2-B only blocked the increase in FSH secretion. LC showed intense stress-induced neuronal activity. FOS/tyrosine-hydroxylase coexpression in LC was reduced by antalarmin, but not astressin2-B. The CRH-R1 receptor, more than CRH-R2 receptor, appears to be essential for the stimulation of the hypothalamus-pituitary-gonad axis by acute stress; this response is likely mediated in part by noradrenergic neurons in the LC. We postulate that the stress-induced facilitation of reproductive function is mediated, at least in part, by CRH action through CRH-R1 on noradrenaline neurons residing in the LC that trigger GnRH discharge and gonadotropin secretion.

scholarly journals Putative Activation of the CB1 Cannabinoid Receptors Prevents Anxiety-Like Behavior, Oxidative Stress, and GABA Decrease in the Brain of Zebrafish Submitted to Acute Restraint Stress

2021 ◽  
Vol 14 ◽  
Author(s):  
Waldo Lucas Luz ◽  
Mateus Santos-Silva ◽  
Patrick Bruno Cardoso ◽  
Nadyme Assad ◽  
Edinaldo Rogério da Silva Moraes ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Restraint Stress ◽  
Cannabinoid Receptors ◽  
Acute Stress ◽  
Control Treatment ◽  
Cb1 Receptors ◽  
Acute Restraint Stress ◽  
Gaba Content ◽  
The Brain

Anxiety disorder is a well-recognized condition observed in subjects submitted to acute stress. Although the brain mechanisms underlying this disorder remain unclear, the available evidence indicates that oxidative stress and GABAergic dysfunction mediate the generation of stress-induced anxiety. Cannabinoids are known to be efficient modulators of behavior, given that the activation of the cannabinoid receptors type-1 (CB1 receptors) induces anxiolytic-like effects in animal models. In the present study, we aimed to describe the effects of the stimulation of the CB1 receptors on anxiety-like behavior, oxidative stress, and the GABA content of the brains of zebrafish submitted to acute restraint stress (ARS). The animals submitted to the ARS protocol presented evident anxiety-like behavior with increased lipid peroxidation in the brain tissue. The evaluation of the levels of GABA in the zebrafish telencephalon presented decreased levels of GABA in the ARS group in comparison with the control. Treatment with ACEA, a specific CB1 receptor agonist, prevented ARS-induced anxiety-like behavior and oxidative stress in the zebrafish brain. ACEA treatment also prevented a decrease in GABA in the telencephalon of the animals submitted to the ARS protocol. Overall, these preclinical data strongly suggest that the CB1 receptors represent a potential target for the development of the treatment of anxiety disorders elicited by acute stress.

scholarly journals Acute Stress Increases the Synthesis of 7α-Hydroxypregnenolone, a New Key Neurosteroid Stimulating Locomotor Activity, through Corticosterone Action in Newts

Endocrinology ◽  
2012 ◽  
Vol 153 (2) ◽  
pp. 794-805 ◽  
Author(s):  
Shogo Haraguchi ◽  
Teppei Koyama ◽  
Itaru Hasunuma ◽  
Shin-ichiro Okuyama ◽  
Takayoshi Ubuka ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Restraint Stress ◽  
Acute Stress ◽  
Behavioral Responses ◽  
Biological Action ◽  
Central Administration ◽  
Steroidogenic Enzyme ◽  
Dorsomedial Hypothalamus ◽  
The Brain ◽  
Double Immunolabeling

7α-Hydroxypregnenolone (7α-OH PREG) is a newly identified bioactive neurosteroid stimulating locomotor activity in the brain of newt, a wild animal, which serves as an excellent model to investigate the biosynthesis and biological action of neurosteroids. Here, we show that acute stress increases 7α-OH PREG synthesis in the dorsomedial hypothalamus (DMH) through corticosterone (CORT) action in newts. A 30-min restraint stress increased 7α-OH PREG synthesis in the brain tissue concomitant with the increase in plasma CORT concentrations. A 30-min restraint stress also increased the expression of cytochrome P4507α (CYP7B), the steroidogenic enzyme of 7α-OH PREG formation, in the DMH. Decreasing plasma CORT concentrations by hypophysectomy or trilostane administration decreased 7α-OH PREG synthesis in the diencephalon, whereas administration of CORT to these animals increased 7α-OH PREG synthesis. Glucocorticoid receptor was present in DMH neurons expressing CYP7B. Thus, CORT appears to act directly on DMH neurons to increase 7α-OH PREG synthesis. We further investigated the biological action of 7α-OH PREG in the brain under stress. A 30-min restraint stress or central administration of 7α-OH PREG increased serotonin concentrations in the diencephalon. Double immunolabeling further showed colocalization of CYP7B and serotonin in the DMH. These results indicate that acute stress increases the synthesis of 7α-OH PREG via CORT action in the DMH, and 7α-OH PREG activates serotonergic neurons in the DMH that may coordinate behavioral responses to stress. This is the first demonstration of neurosteroid biosynthesis regulated by peripheral steroid hormone and of neurosteroid action in the brain under stress in any vertebrate class.

Kisspeptins and Reproduction: Physiological Roles and Regulatory Mechanisms

2012 ◽  
Vol 92 (3) ◽  
pp. 1235-1316 ◽  
Author(s):  
Leonor Pinilla ◽  
Enrique Aguilar ◽  
Carlos Dieguez ◽  
Robert P. Millar ◽  
Manuel Tena-Sempere
Keyword(s):  
Biological Effects ◽  
Reproductive Function ◽  
Future Research ◽  
Gonadotropin Secretion ◽  
Integral Control ◽  
Molecular Features ◽  
Hypothalamic Nuclei ◽  
Key Aspects ◽  
And Function ◽  
The Brain

Procreation is essential for survival of species. Not surprisingly, complex neuronal networks have evolved to mediate the diverse internal and external environmental inputs that regulate reproduction in vertebrates. Ultimately, these regulatory factors impinge, directly or indirectly, on a final common pathway, the neurons producing the gonadotropin-releasing hormone (GnRH), which stimulates pituitary gonadotropin secretion and thereby gonadal function. Compelling evidence, accumulated in the last few years, has revealed that kisspeptins, a family of neuropeptides encoded by the Kiss1 gene and produced mainly by neuronal clusters at discrete hypothalamic nuclei, are pivotal upstream regulators of GnRH neurons. As such, kisspeptins have emerged as important gatekeepers of key aspects of reproductive maturation and function, from sexual differentiation of the brain and puberty onset to adult regulation of gonadotropin secretion and the metabolic control of fertility. This review aims to provide a comprehensive account of the state-of-the-art in the field of kisspeptin physiology by covering in-depth the consensus knowledge on the major molecular features, biological effects, and mechanisms of action of kisspeptins in mammals and, to a lesser extent, in nonmammalian vertebrates. This review will also address unsolved and contentious issues to set the scene for future research challenges in the area. By doing so, we aim to endow the reader with a critical and updated view of the physiological roles and potential translational relevance of kisspeptins in the integral control of reproductive function.

scholarly journals Intrahypothalamic Estradiol Modulates Hypothalamus-Pituitary-Adrenal-Axis Activity in Female Rats

Endocrinology ◽  
2012 ◽  
Vol 153 (7) ◽  
pp. 3337-3344 ◽  
Author(s):  
J. Liu ◽  
P. H. Bisschop ◽  
L. Eggels ◽  
E. Foppen ◽  
E. Fliers ◽  
...  
Keyword(s):  
Hpa Axis ◽  
Restraint Stress ◽  
Acute Stress ◽  
Plasma Corticosterone ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Stress Exposure ◽  
Ici 182,780 ◽  
Hpa Axis Activity

Estrogen plays an important role in the regulation of the hypothalamus-pituitary-adrenal (HPA)-axis, but the neuroendocrine pathways and the role of estrogen receptor (ER) subtypes involved in specific aspects of this interaction remain unknown. In a first set of experiments, we administered estradiol (E2) intravenously, intracerebroventricularly, and by intrahypothalamic microdialysis to ovariectomized rats to measure plasma corticosterone (CORT) concentrations from carotid artery blood. Systemic infusion of E2 did not increase plasma CORT, but intracerebroventricular E2 induced a 3-fold CORT increase (P = 0.012). Local E2 infusions in the hypothalamic paraventricular nucleus (PVN) significantly increased plasma CORT (P < 0.001). A similar CORT increase was seen after PVN infusion of the ERα agonist propylpyrazoletriol, whereas the ERβ agonist diarylpropiolnitrile had no effect. In a second set of experiments, we investigated whether E2 modulates the HPA-axis response to acute stress by administering E2 agonists or its antagonist ICI 182,780 into the PVN during restraint stress exposure. After 30 min of stress exposure, plasma CORT had increased 5.0-fold (P < 0.001). E2 and propylpyrazoletriol administration in the PVN enhanced the stress-induced plasma CORT increase (8-fold vs. baseline), whereas ICI 182,780 and diarylpropiolnitrile reduced it, as compared with both E2 and vehicle administration in the PVN. In conclusion, central E2 modulates HPA-axis activity both in the basal state and during restraint stress. In the basal condition, the stimulation is mediated by ERα-sensitive neurons, whereas during stress, it is mediated by both ERα and ERβ.

Regional Serotonin Metabolism under Basal and Restraint Stress Conditions in the Brain of Transgenic Mice with Impaired Glucocorticoid Receptor Function

1999 ◽  
Vol 70 (6) ◽  
pp. 413-421 ◽  
Author(s):  
Jean Farisse ◽  
Pascale Boulenguez ◽  
Alexandra Sémont ◽  
Francis Héry ◽  
Nicholas Barden ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Glucocorticoid Receptor ◽  
Restraint Stress ◽  
Stress Conditions ◽  
Serotonin Metabolism ◽  
Receptor Function ◽  
The Brain

scholarly journals Programming of the reproductive axis by hormonal and genetic manipulation in mice

Reproduction ◽  
2018 ◽  
Author(s):  
Susana B Rulli ◽  
María Julia Cambiasso ◽  
Laura D Ratner
Keyword(s):  
Sex Chromosome ◽  
Genetic Manipulation ◽  
Sex Differentiation ◽  
Reproductive Function ◽  
Gonadal Steroids ◽  
Critical Periods ◽  
Female Reproduction ◽  
Control Male ◽  
Male And Female ◽  
The Brain

In mammals, the reproductive function is controlled by the hypothalamic-pituitary-gonadal axis. During development, mechanisms mediated by gonadal steroids exert an imprinting at the hypothalamic-pituitary level, by establishing sexual differences in the circuits that control male and female reproduction. In rodents, the testicular production of androgens increases drastically during the fetal/neonatal stage. This process is essential for the masculinization of the reproductive tract, genitals and brain. The conversion of androgens to estrogens in the brain is crucial for the male sexual differentiation and behavior. Conversely, feminization of the brain occurs in the absence of high levels of gonadal steroids during the perinatal period in females. Potential genetic contribution to the differentiation of brain cells through direct effects of genes located on sex chromosomes is also relevant. In this review, we will focus on the phenotypic alterations that occur on the hypothalamic-pituitary-gonadal axis of transgenic mice with persistently elevated expression of the human chorionic gonadotropin hormone (hCG). Excess of endogenously synthesized gonadal steroids due to a constant hCG stimulation is able to disrupt the developmental programming of the hypothalamic-pituitary axis in both transgenic males and females. Locally produced estrogens by the hypothalamic aromatase might play a key role in the phenotype of these mice. The “four core genotypes” mouse model demonstrated a potential influence of sex chromosome genes in brain masculinization before critical periods of sex differentiation. Thus, hormonal and genetic factors interact to regulate the local production of the neurosteroids necessary for the programming of the male and female reproductive function.

scholarly journals ICI 182,780 Penetrates Brain and Hypothalamic Tissue and Has Functional Effects in the Brain after Systemic Dosing

Endocrinology ◽  
2008 ◽  
Vol 149 (10) ◽  
pp. 5219-5226 ◽  
Author(s):  
Peter D. Alfinito ◽  
Xiaohong Chen ◽  
James Atherton ◽  
Scott Cosmi ◽  
Darlene C. Deecher
Keyword(s):  
Body Weight ◽  
Skin Temperature ◽  
Ethinyl Estradiol ◽  
Ovariectomized Rats ◽  
Ici 182,780 ◽  
Hot Flush ◽  
Hypothalamic Tissue ◽  
Dependent Model ◽  
The Brain ◽  
Neuroendocrine Functions

Previous reports suggest the antiestrogen ICI 182,780 (ICI) does not cross the blood-brain barrier (BBB). However, this hypothesis has never been directly tested. In the present study, we tested whether ICI crosses the BBB, penetrates into brain and hypothalamic tissues, and affects known neuroendocrine functions in ovariectomized rats. Using HPLC with mass spectrometry, ICI (1.0 mg/kg·d, 3 d) was detected in plasma and brain and hypothalamic tissues for up to 24 h with maximum concentrations of 43.1 ng/ml, and 31.6 and 38.8 ng/g, respectively. To evaluate antiestrogenic effects of ICI in the brain after systemic dosing, we tested its ability to block the effect of 17 α-ethinyl estradiol (EE) (0.3 mg/kg, 8 d) on tail-skin temperature abatement in the morphine-dependent model of hot flush and on body weight change. In the morphine-dependent model, EE abated 64% of the naloxone-induced tail-skin temperature increase. ICI pretreatment (1.0, 3.0 mg/kg·d) dose dependently inhibited this effect. ICI (3.0 mg/kg·d) alone showed estrogenic-like actions, abating 30% the naloxone-induced flush. In body weight studies, EE-treated rats weighed 58.5 g less than vehicle-treated rats after 8 d dosing. This effect was partially blocked by ICI (3.0 mg/kg·d) pretreatment. Similar to EE treatment, rats receiving 1.0 or 3.0 mg/kg·d ICI alone showed little weight gain compared with vehicle-treated controls. Thus, ICI crosses the BBB, penetrates into brain and hypothalamic tissues, and has both antiestrogenic and estrogenic-like actions on neuroendocrine-related functions.

scholarly journals C60 Fullerene Prevents Restraint Stress-Induced Oxidative Disorders in Rat Tissues: Possible Involvement of the Nrf2/ARE-Antioxidant Pathway

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Olga O. Gonchar ◽  
Andriy V. Maznychenko ◽  
Nataliya V. Bulgakova ◽  
Inna V. Vereshchaka ◽  
Tomasz Tomiak ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Protein Expression ◽  
Restraint Stress ◽  
Stress Condition ◽  
Rat Tissues ◽  
Stress Exposure ◽  
The Brain ◽  
Nrf2 Protein

The effects of C60FAS (50 and 500 μg/kg) supplementation, in a normal physiological state and after restraint stress exposure, on prooxidant/antioxidant balance in rat tissues were explored and compared with the effects of the known exogenous antioxidant N-acetylcysteine. Oxidative stress biomarkers (ROS, O2⋅−, H2O2, and lipid peroxidation) and indices of antioxidant status (MnSOD, catalase, GPx, GST, γ-GCL, GR activities, and GSH level) were measured in the brain and the heart. In addition, protein expression of Nrf2 in the nuclear and cytosol fractions as well as the protein level of antiradical enzyme MnSOD and GSH-related enzymes γ-GCLC, GPx, and GSTP as downstream targets of Nrf2 was evaluated by western blot analysis. Under a stress condition, C60FAS attenuates ROS generation and O2⋅− and H2O2 releases and thus decreases lipid peroxidation as well as increases rat tissue antioxidant capacity. We have shown that C60FAS supplementation has dose-dependent and tissue-specific effects. C60FAS strengthened the antiradical defense through the upregulation of MnSOD in brain cells and maintained MnSOD protein content at the control level in the myocardium. Moreover, C60FAS enhanced the GSH level and the activity/protein expression of GSH-related enzymes. Correlation of these changes with Nrf2 protein content suggests that under stress exposure, along with other mechanisms, the Nrf2/ARE-antioxidant pathway may be involved in regulation of glutathione homeostasis. In our study, in an in vivo model, when C60FAS (50 and 500 μg/kg) was applied alone, no significant changes in Nrf2 protein expression as well as in activity/protein levels of MnSOD and GSH-related enzymes in both tissues types were observed. All these facts allow us to assume that in the in vivo model, C60FAS affects on the brain and heart endogenous antioxidative statuses only during the oxidative stress condition.

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