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.

scholarly journals Vitamin A regulates hypothalamic–pituitary–adrenal axis status in LOU/C rats

2013 ◽  
Vol 219 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Nathalie Marissal-Arvy ◽  
Rachel Hamiani ◽  
Emmanuel Richard ◽  
Marie-Pierre Moisan ◽  
Véronique Pallet
Keyword(s):  
Vitamin A ◽  
Hpa Axis ◽  
Restraint Stress ◽  
Vitamin A Deficiency ◽  
Plasma Corticosterone ◽  
Hypothalamic Pituitary Adrenal ◽  
Corticosteroid Receptors ◽  
Vitamin A Status ◽  
Corticosterone Response ◽  
Hpa Axis Activity

The aim of this study was to explore the involvement of retinoids in the hypoactivity and hyporeactivity to stress of the hypothalamic–pituitary–adrenal (HPA) axis in LOU/C rats. We measured the effects of vitamin A deficiency administered or not with retinoic acid (RA) on plasma corticosterone in standard conditions and in response to restraint stress and on hypothalamic and hippocampal expression of corticosteroid receptors, corticotropin-releasing hormone and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in LOU/C rats. Interestingly, under control conditions, we measured a higher plasma concentration of retinol in LOU/C than in Wistar rats, which could contribute to the lower basal activity of the HPA axis in LOU/C rats. Vitamin A deficiency induced an increased HPA axis activity in LOU/C rats, normalized by RA administration. Compared with LOU/C control rats, vitamin A-deficient rats showed a delayed and heightened corticosterone response to restraint stress. The expression of corticosteroid receptors was strongly decreased by vitamin A deficiency in the hippocampus, which could contribute to a less efficient feedback by corticosterone on HPA axis tone. The expression of 11β-HSD1 was increased by vitamin A deficiency in the hypothalamus (+62.5%) as in the hippocampus (+104.7%), which could lead to a higher production of corticosterone locally and contribute to alteration of the hippocampus. RA supplementation treatment restored corticosterone concentrations and 11β-HSD1 expression to control levels. The high vitamin A status of LOU/C rats could contribute to their low HPA axis activity/reactivity and to a protective effect against 11β-HSD1-mediated deleterious action on cognitive performances during ageing.

scholarly journals Endomorphins and activation of the hypothalamo-pituitary-adrenal axis

2001 ◽  
Vol 169 (1) ◽  
pp. 185-193 ◽  
Author(s):  
TL Coventry ◽  
DS Jessop ◽  
DP Finn ◽  
MD Crabb ◽  
H Kinoshita ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Hpa Axis ◽  
Restraint Stress ◽  
Acute Stress ◽  
Plasma Corticosterone ◽  
Mu Opioid Receptor ◽  
Inflammatory Stress ◽  
Mu Opioid ◽  
Beta Endorphin ◽  
Immune Tissues

Endomorphin (EM)-1 and EM-2 are opioid tetrapeptides recently located in the central nervous system and immune tissues with high selectivity and affinity for the mu-opioid receptor. Intracerebroventricular (i.c.v.) administration of morphine stimulates the hypothalamo-pituitary-adrenal (HPA) axis. The present study investigated the effect of centrally administered EM-1 and EM-2 on HPA axis activation. Rats received a single i.c.v. injection of either EM-1 (0.1, 1.0, 10 microg), EM-2 (10 microg), morphine (10 microg), or vehicle (0.9% saline). Blood samples for plasma corticosterone determinations were taken immediately prior to i.c.v. administration and at various time points up to 4 h post-injection. Trunk blood, brains and pituitaries were collected at 4 h. Intracerebroventricular morphine increased plasma corticosterone levels within 30 min, whereas EM-1 and EM-2 were without effect. In addition, pre-treatment of i.c.v. EM-1 did not block the rise in corticosterone after morphine. Corticotrophin-releasing factor (CRF) mRNA and arginine vasopressin (AVP) mRNA in the paraventricular nucleus (PVN) and POMC mRNA in the anterior pituitary were found to be unaffected by either morphine or endomorphins. Since release of other opioids are elevated in response to acute stress, we exposed rats to a range of stressors to determine whether plasma EM-1 and EM-2 can be stimulated by HPA axis activation. Plasma corticosterone, ACTH and beta-endorphin were elevated following acute restraint stress, but concentrations of plasma EM-1-immunoreactivity (ir) and EM-2-ir did not change significantly. Corticosterone, ACTH and beta-endorphin were further elevated in adjuvant-induced arthritis (AA) rats by a single injection of lipopolysaccharide (LPS), but not by restraint stress. In conclusion, neither EM-1 or EM-2 appear to influence the regulation of the HPA axis. These data suggest that endomorphins may be acting on a different subset of the mu-opioid receptor than morphine. The failure to induce changes in plasma EM-ir in response to the chronic inflammatory stress of AA, the acute immunological stress of LPS, or the psychological stress of restraint, argues against an important role for endomorphins in mediating HPA axis activity.

Neonatal monosodium glutamate treatment alters both the activity and the sensitivity of the rat hypothalamo-pituitary-adrenocortical axis

1994 ◽  
Vol 141 (3) ◽  
pp. 497-503 ◽  
Author(s):  
P J Larsen ◽  
J D Mikkelsen ◽  
D Jessop ◽  
S L Lightman ◽  
H S Chowdrey
Keyword(s):  
Hpa Axis ◽  
Restraint Stress ◽  
Acute Stress ◽  
Monosodium Glutamate ◽  
Plasma Corticosterone ◽  
Mrna Levels ◽  
Plasma Acth ◽  
Corticotrophin Releasing Factor ◽  
Acute And Chronic Stress ◽  
Corticosterone Response

Abstract We have investigated the effects of monosodium glutamate (MSG) lesioning of the arcuate nucleus on both central and peripheral components of the hypothalamo-pituitary-adrenocortical (HPA) axis under basal conditions and under acute and chronic stress. Plasma ACTH levels were lower in MSG-lesioned rats (27 ± 7 pg/ml) compared with controls (71 ± 18 pg/ml) while corticosterone levels were elevated (523 ± 84 ng/ml compared with 176 ± 34 ng/ml). Quantititative in situ hybridization histochemistry revealed that corticotrophin-releasing factor mRNA levels in the medial parvocellular part of the hypothalamic paraventricular nucleus were significantly lower in MSG-treated rats. MSG lesioning resulted in an enhanced response of corticosterone to restraint stress (1309 ± 92 ng/ml compared with 628 ± 125 ng/ml in sham-lesioned animals), while ACTH responses to restraint stress in MSG-lesioned and sham-MSG groups were not significantly different (160 ± 24 pg/ml and 167 ± 24 pg/ml respectively). These data suggest that MSG-lesioned rats have an increased adrenocortical sensitivity. In rats subjected to the chronic osmotic stimulus of drinking 2% saline for 12 days, plasma ACTH levels were significantly reduced (15 ± 5 pg/ml) and the ACTH and corticosterone responses to restraint stress were eliminated. ACTH levels were also reduced in MSG-treated animals given 2% saline and the ACTH response to acute stress remained absent in these animals. However, a robust corticosterone response to restraint stress was observed in saline-treated MSG-lesioned rats. These data demonstrate that MSG lesioning results in elevated basal and stress-induced plasma corticosterone, and restores the adrenocortical response to stress which is absent in chronically osmotically stimulated rats. The evidence is consistent with the suggestion that MSG lesions a pathway involved in tonic inhibition of the HPA axis. In addition, the adrenocortical sensitivity to ACTH and other secretagogues may be increased in MSG-treated animals. Journal of Endocrinology (1994) 141, 497–503

scholarly journals TheKampoMedicine Yokukansan Decreases MicroRNA-18 Expression and Recovers Glucocorticoid Receptors Protein Expression in the Hypothalamus of Stressed Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Shoko Shimizu ◽  
Takashi Tanaka ◽  
Takashi Takeda ◽  
Masaya Tohyama ◽  
Shingo Miyata
Keyword(s):  
Hpa Axis ◽  
Stress Responses ◽  
Glucocorticoid Receptors ◽  
Psychological Symptoms ◽  
Plasma Corticosterone ◽  
Mrna Levels ◽  
Stress Exposure ◽  
Protein Levels ◽  
Hpa Axis Activity ◽  
The Brain

It is well known that glucocorticoid receptor (GR) signaling regulates the hypothalamic-pituitary-adrenal (HPA) axis, and GR expression level is associated with HPA axis activity. Recent studies revealed that microRNA- (miR-) 18 and/or 124a are candidate negative regulators of GR in the brain. TheKampomedicine Yokukansan (YKS) can affect psychological symptoms such as depression and anxiety that are associated with stress responses. In this study, we evaluated the effect of YKS on miR-18 and 124a and GR levels in mice exposed to stress. We found that YKS pretreatment normalized elevated plasma corticosterone levels in stress-exposed mice. In addition, GR mRNA levels were downregulated in the brain following stress exposure. While miR-124a expression levels were not altered in the hypothalamus of stress-exposed mice, miR-18 levels decreased in the hypothalamus of YKS-pretreated mice after stress exposure. Finally, GR protein levels in the paraventricular nucleus (PVN) of the hypothalamus after stress exposure recovered in YKS-pretreated mice. Collectively, these data suggest that YKS normalizes GR protein levels by regulating miR-18 expression in the hypothalamus, thus normalizing HPA axis activity following stress exposure.

scholarly journals The vagus nerve is critical for regulation of hypothalamic-pituitary-adrenal axis responses to acute stress

2021 ◽  
Author(s):  
Bailey N Keller ◽  
Angela E Snyder ◽  
Caitlin R Coker ◽  
Elizabeth A Aguilar ◽  
Mary K O'Brien ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Hpa Axis ◽  
Restraint Stress ◽  
Acute Stress ◽  
Plasma Corticosterone ◽  
Action Potential Firing ◽  
Acute Restraint Stress ◽  
Potential Firing ◽  
Crf Neurons ◽  
Hpa Function

The hypothalamic pituitary adrenal (HPA) axis is a critical regulator of physiologic and psychological responses to acute and chronic stressors. HPA axis function is control by numerous feedback inhibitory mechanisms, disruptions of which can lead to various psychiatric conditions, such as depression, posttraumatic stress disorder, and schizophrenia. Vagus nerve stimulation has been shown to be efficacious in these various mental health issues potentially via modulation of HPA axis function, but the mechanisms by which the vagus nerve may regulate HPA function has not been fully elucidated. In the present studies, we sought to test the hypothesis that the vagus nerve is a critical regulator of HPA function. Neuroendocrine function and neurocircuit changes in corticotropin releasing factor (CRF) neurons in the paraventricular nucleus of the hypothalamus (PVN) was examined following acute stress after subdiaphragmatic left vagotomy (VX) in adult male Sprague-Dawley rats. We found that VX mimics HPA activation seen in sham surgery animals exposed to acute restraint stress, particularly increased plasma corticosterone levels, elevated PVN CRF mRNA, and increased action potential firing of putative CRF neurons in PVN brain slices. Furthermore, VX animals exposed to acute restraint stress showed increased elevations of plasma corticosterone and PVN CRF mRNA which may be due to lack of compensatory PVN GABAergic signaling in response to acute stress. Both Sham/Stress and VX/no stress conditions increases action potential firing in putative PVN CRF neurons, but this effect was not seen in the VX/stress condition, suggesting that not all forms of stress compensation are lost following VX. Overall, these findings suggest that the vagus nerve may play a critical role in regulating HPA axis function via modulation of local PVN neurocircuit activity.

scholarly journals The Increase in Signaling by Kisspeptin Neurons in the Preoptic Area and Associated Changes in Clock Gene Expression That Trigger the LH Surge in Female Rats Are Dependent on the Facilitatory Action of a Noradrenaline Input

Endocrinology ◽  
2016 ◽  
Vol 157 (1) ◽  
pp. 323-335 ◽  
Author(s):  
Bruna Kalil ◽  
Aline B. Ribeiro ◽  
Cristiane M. Leite ◽  
Ernane T. Uchôa ◽  
Ruither O. Carolino ◽  
...  
Keyword(s):  
Gene Expression ◽  
Median Eminence ◽  
Preoptic Area ◽  
Clock Genes ◽  
Third Ventricle ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Lh Surge ◽  
Clock Gene Expression

Abstract In rodents, kisspeptin neurons in the rostral periventricular area of the third ventricle (RP3V) of the preoptic area are considered to provide a major stimulatory input to the GnRH neuronal network that is responsible for triggering the preovulatory LH surge. Noradrenaline (NA) is one of the main modulators of GnRH release, and NA fibers are found in close apposition to kisspeptin neurons in the RP3V. Our objective was to interrogate the role of NA signaling in the kisspeptin control of GnRH secretion during the estradiol induced LH surge in ovariectomized rats, using prazosin, an α1-adrenergic receptor antagonist. In control rats, the estradiol-induced LH surge at 17 hours was associated with a significant increase in GnRH and kisspeptin content in the median eminence with the increase in kisspeptin preceding that of GnRH and LH. Prazosin, administered 5 and 3 hours prior to the predicted time of the LH surge truncated the LH surge and abolished the rise in GnRH and kisspeptin in the median eminence. In the preoptic area, prazosin blocked the increases in Kiss1 gene expression and kisspeptin content in association with a disruption in the expression of the clock genes, Per1 and Bmal1. Together these findings demonstrate for the first time that NA modulates kisspeptin synthesis in the RP3V through the activation of α1-adrenergic receptors prior to the initiation of the LH surge and indicate a potential role of α1-adrenergic signaling in the circadian-controlled pathway timing of the preovulatory LH surge.

Acute Stress Induced Behavioral Deficits In Rats: Relationship With Oxidative Stress, Leptin And HPA Axis

2019 ◽  
Vol 41 (5) ◽  
pp. 859-859
Author(s):  
Erum Shireen Erum Shireen ◽  
Wafa Binte Ali Wafa Binte Ali ◽  
Maria Masroor Maria Masroor ◽  
Saeeda Bano Saeeda Bano ◽  
Samina Iqbal Samina Iqbal ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Open Field ◽  
Hpa Axis ◽  
Acute Stress ◽  
Antioxidant Properties ◽  
Oxidative Enzymes ◽  
Behavioral Deficits ◽  
Glucose Estimation ◽  
Dark Transition

Acute exposure to stress is connected to many disorders that promote the toxicity of oxygen radical generators leading to increase in the levels of enzymes and also the activation of the HPA axis. The present study uses a preclinical approach to elucidate some prospective stress-induced behavioral and biochemical effects. The aim of current study was to investigate the relationship between stress and behavioral changes after exposing animals to 2h immobilization stress. We also evaluated the concentration of corticosterone, glucose and endogenous leptin levels in unstressed and stressed animals to explore the possible role of HPA axis in the modulation of stressed induced behavioral deficits. Rats were divided into stressed and unstressed groups. Behavioral activities were monitored in open field activity and light dark transition box after the termination of 2h immobilization period. Animals were then decapitated and plasma samples were collected for catalase, SOD, corticosterone, and glucose estimation. Results showed that exposure to acute stress produced a significant decrease in the activity of rats in the novel environment (open field) and light dark transition box. On the other hand, concomitant elevated level of peripheral markers of oxidative stress such as oxidative enzymes, corticosterone and endogenous leptin were also observed. Therefore, current study seems to suggest an important role of compounds having antioxidant properties for the treatment of stress and related disorders.

The effect of acute stress exposure on ischemia and reperfusion injury in rat heart: Role of oxytocin

Stress ◽  
2011 ◽  
Vol 15 (4) ◽  
pp. 385-392 ◽  
Author(s):  
Maryam Moghimian ◽  
Mahdieh Faghihi ◽  
Seyed Morteza Karimian ◽  
Alireza Imani
Keyword(s):  
Reperfusion Injury ◽  
Rat Heart ◽  
Acute Stress ◽  
Ischemia And Reperfusion ◽  
Stress Exposure ◽  
Ischemia And Reperfusion Injury

Estrogen potentiates adrenocortical responses to stress in female rats

2007 ◽  
Vol 292 (4) ◽  
pp. E1173-E1182 ◽  
Author(s):  
Helmer F. Figueiredo ◽  
Yvonne M. Ulrich-Lai ◽  
Dennis C. Choi ◽  
James P. Herman
Keyword(s):  
Mrna Expression ◽  
Acute Stress ◽  
Physiological Mechanism ◽  
Plasma Corticosterone ◽  
Female Rats ◽  
Inhibitory Effects ◽  
Ovx Rats ◽  
Glucocorticoid Response ◽  
Unexpected Findings ◽  
Adrenocortical Responses

It is well established that estrogens markedly enhance the glucocorticoid response to acute stress in females. However, the precise mechanism responsible for this regulation is poorly understood. Here, we tested whether estrogens enhance the activation of the paraventricular nucleus (PVN) of the hypothalamus by measuring stress-induced c- fos mRNA expression in the PVN of restraint-stressed ovariectomized (OVX) rats treated with physiologically relevant doses of estradiol (E2), the major female estrogen. As expected, E2 enhanced plasma corticosterone responses to restraint in OVX females. However, E2 markedly attenuated the stress-induced c- fos gene expression in the PVN and inhibited plasma ACTH responses in these animals. Furthermore, E2-inhibitory effects were mimicked by progesterone (P) alone or in combination with E2. Interestingly, the suppressive central effects of both E2 and P were apparently independent of basal paraventricular corticotropin-releasing hormone (CRH) transcription, since these ovarian steroids did not significantly affect PVN CRH mRNA expression in unstressed rats. These unexpected findings suggested that E2 promotes glucocorticoid hypersecretion in females by additional peripheral (i.e., adrenal) mechanisms. Indeed, E2 markedly enhanced plasma corticosterone responses and adrenal corticosterone content in dexamethasone-blocked OVX rats challenged with varying doses of exogenous ACTH. These results suggest that enhanced adrenal sensitive to ACTH is an important physiological mechanism mediating E2-related glucocorticoid hypersecretion in stressed females.

scholarly journals Overexpression of Corticotropin Releasing Factor in the Central Nucleus of the Amygdala Advances Puberty and Disrupts Reproductive Cycles in Female Rats

Endocrinology ◽  
2014 ◽  
Vol 155 (10) ◽  
pp. 3934-3944 ◽  
Author(s):  
X. F. Li ◽  
M. H. Hu ◽  
S. Y. Li ◽  
C. Geach ◽  
A. Hikima ◽  
...  
Keyword(s):  
Chronic Stress ◽  
Hpa Axis ◽  
Pulse Generator ◽  
Female Rats ◽  
Central Nucleus ◽  
Ovariectomized Rats ◽  
Human Society ◽  
Central Administration ◽  
Corticosterone Secretion ◽  
Stress Changes

Abstract Prolonged exposure to environmental stress activates the hypothalamic-pituitary-adrenal (HPA) axis and generally disrupts the hypothalamic-pituitary-gonadal axis. Because CRF expression in the central nucleus of the amygdala (CeA) is a key modulator in adaptation to chronic stress, and central administration of CRF inhibits the hypothalamic GnRH pulse generator, we tested the hypothesis that overexpression of CRF in the CeA of female rats alters anxiety behavior, dysregulates the HPA axis response to stress, changes pubertal timing, and disrupts reproduction. We used a lentiviral vector to increase CRF expression site specifically in the CeA of preweaning (postnatal day 12) female rats. Overexpression of CRF in the CeA increased anxiety-like behavior in peripubertal rats shown by a reduction in time spent in the open arms of the elevated plus maze and a decrease in social interaction. Paradoxically, puberty onset was advanced but followed by irregular estrous cyclicity and an absence of spontaneous preovulatory LH surges associated with proestrous vaginal cytology in rats overexpressing CRF. Despite the absence of change in basal corticosterone secretion or induced by stress (lipopolysaccharide or restraint), overexpression of CRF in the CeA significantly decreased lipopolysaccharide, but not restraint, stress-induced suppression of pulsatile LH secretion in postpubertal ovariectomized rats, indicating a differential stress responsivity of the GnRH pulse generator to immunological stress and a potential adaptation of the HPA axis to chronic activation of amygdaloid CRF. These data suggest that the expression profile of this key limbic brain CRF system might contribute to the complex neural mechanisms underlying the increasing incidence of early onset of puberty on the one hand and infertility on the other attributed to chronic stress in modern human society.

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