Corticotropin Releasing Research Articles

Anterior pituitary gland synthesises dopamine from l-3,4-dihydroxyphenylalanine (l-dopa).

Prolactin (PRL) is a hormone principally secreted by lactotrophs of the anterior pituitary gland. Although the synthesis and exocytosis of this hormone are mainly under the regulation of hypothalamic dopamine (DA), the possibility that the anterior pituitary synthesises this catecholamine remains unclear. The present study aimed to determine if the anterior pituitary produces DA from the precursor l-3,4-dihydroxyphenylalanine (l-dopa). Accordingly, we investigated the expression of aromatic l-amino acid decarboxylase (AADC) enzyme and the transporter vesicular monoamine transporter 2 (VMAT2) in the anterior pituitary, AtT20 and GH3 cells by immunofluorescence and western blotting. Moreover, we investigated the production of DA from l-dopa and its release in vitro. Then, we explored the effects of l-dopa with respect to the secretion of PRL from anterior pituitary fragments. We observed that the anterior pituitary, AtT20 and GH3 cells express both AADC and VMAT2. Next, we detected an increase in DA content after anterior pituitary fragments were incubated with l-dopa. Also, the presence of l-dopa increased DA levels in incubation media and reduced PRL secretion. Likewise, the content of cellular DA increased after AtT20 cells were incubated with l-dopa. In addition, l-dopa reduced corticotrophin-releasing hormone-stimulated adrenocorticotrophic hormone release from these cells after AADC activity was inhibited by NSD-1015. Moreover, DA formation from l-dopa increased apoptosis and decreased proliferation. However, in the presence of NSD-1015, l-dopa decreased apoptosis and increased proliferation rates. These results suggest that the anterior pituitary synthesises DA from l-dopa by AADC and this catecholamine can be released from this gland contributing to the control of PRL secretion. In addition, our results suggest that l-dopa exerts direct actions independently from its metabolisation to DA.

Hypothalamic-Pituitary-Adrenal Axis Responses in Women with Endometriosis-Related Chronic Pelvic Pain.

Some chronic pain conditions and comorbidities suppress the hypothalamic-pituitary-adrenal (HPA) axis and response to dynamic testing. We measured HPA axis responses to corticotropin-releasing hormone (CRH) administration in relation to chronic pelvic pain and endometriosis. In a cross-sectional study of women (n = 54) with endometriosis-associated chronic pelvic pain (n = 22), chronic pelvic pain alone (n = 12), or healthy volunteers (n = 20), adrenocorticotropic-releasing hormone (ACTH) and cortisol levels were measured at 0, 15, 30, and 45min after intravenous ovine CRH administration. ACTH and cortisol delta (peak-baseline) and area under the curve (AUC) were compared by study group and assessed for association with race and menstrual and non-menstrual pain severity. HPA axis responses did not differ among the racially diverse groups or in those with pain compared with healthy volunteers. However, when stratified by race, ACTH delta (129.9 ± 130.7 vs. 52.5 ± 66.0pg/mL; p = 0.003), ACTH AUC (4813 ± 4707 vs. 2290 ± 2900min*pg/mL; p = 0.013), and cortisol delta (26.3 ± 21.5 vs. 13.2 ± 9.7μg/mL; p = 0.005) were significantly higher in black (n = 10) than predominately white (non-black) subjects (n = 44; 39/44 white). In analyses among primarily white (non-black) women, greater menstrual pain severity was associated with blunted ACTH delta (p = 0.015) and cortisol delta (p = 0.023), and greater non-menstrual pain severity with blunted cortisol delta (p = 0.017). Neuroendocrine abnormalities in women with chronic pelvic pain may differ by pain manifestations and may vary by race. The higher HPA axis response in black women merits investigation in pelvic pain studies stratified by race. In white (non-black) women experiencing pain, a blunted response was related to pain severity suggesting pain affects women independently of endometriosis lesions.

Physiological Effect of Ghrelin on Body Systems.

Ghrelin is a relatively novel multifaceted hormone that has been found to exert a plethora of physiological effects. In this review, we found/confirmed that ghrelin has effect on all body systems. It induces appetite; promotes the use of carbohydrates as a source of fuel while sparing fat; inhibits lipid oxidation and promotes lipogenesis; stimulates the gastric acid secretion and motility; improves cardiac performance; decreases blood pressure; and protects the kidneys, heart, and brain. Ghrelin is important for learning, memory, cognition, reward, sleep, taste sensation, olfaction, and sniffing. It has sympatholytic, analgesic, antimicrobial, antifibrotic, and osteogenic effects. Moreover, ghrelin makes the skeletal muscle more excitable and stimulates its regeneration following injury; delays puberty; promotes fetal lung development; decreases thyroid hormone and testosterone; stimulates release of growth hormone, prolactin, glucagon, adrenocorticotropic hormone, cortisol, vasopressin, and oxytocin; inhibits insulin release; and promotes wound healing. Ghrelin protects the body by different mechanisms including inhibition of unwanted inflammation and induction of autophagy. Having a clear understanding of the ghrelin effect in each system has therapeutic implications. Future studies are necessary to elucidate the molecular mechanisms of ghrelin actions as well as its application as a GHSR agonist to treat most common diseases in each system without any paradoxical outcomes on the other systems.

SUN-LB34 A Case of BMAH With Aberrant Vasopressin Adrenal Receptors

We report on a 42 - year old woman was referred following an incidental finding of bilateral macronodular (nodules > 1cm) adrenal glands after a computed tomography scan for investigation of an unrelated urological problem. Clear features of Cushing’s syndrome were elicited on initial clincal evaluation and screening tests confirmed the diagnosis biochemically: midnight salivary cortisol 15.4nmol/L (0.2 - 3nmol/L), 24 hour urine free cortisol > 662.4nmol/L (8.3 - 118.7nmol/L per 24 hours) and an 8am serum cortisol measured 951nmol/L following 1mg dexamethasone suppression test (< 50nm/L). A serum adrenocorticotropic hormone (ACTH) measured 0.3pmol/L (1.6 - 13.9pmol/L) suggesting, in light of the CT findings, an adrenal source of the elevated cortisol. Screening for aberrant adrenal receptors to catecholamines, Gastric inhibitory peptide, ACTH, vasopressin and Gonadotropin releasing hormone was performed. A positive biochemical response to ACTH and vasopressin was noted as measured serum cortisol increased to 1600pmol/L (upper limit of the assay). Following a unilateral adrenalectomy, were pathological examination of the respected adrenal gland confirmed adrenal hyperplasia, the patient had both clinical and biochemical resolution of hypercortisolemia. 2 weeks following surgery her midnight salivary cortisol measured 2.1nmol/L (0.2 - 3nmol/L) and 24 hour urine free cortisol 218nmol/L (8.3 - 118.7nmol/L per 24 hours). Her 8am ACTH also increased to 2.9pmol/L (1.6 - 13.9pmol/L). Biochemical screening of her sister showed no evidence of Cushing’s syndrome. Bilateral macronodualr hyperplasia (BMAH) represents a rare cause of Cushing’s syndrome may be diagnosed incidentally and is often associated with an insidious onset. We use this case to highlight the complexities of provocative testing for aberrant adrenal receptors which occur with BMAH and the utilization of unilateral adrenalectomy to achieve clinical and biochemical remission of Cushing’s syndrome thus, removing the need for post - operative steroid replacement following bilateral adrenalectomy.

OR25-03 The Effects of Crinecerfont (NBI-74788), a Novel CRF1 Receptor Antagonist, on Adrenal Androgens and Precursors in Patients with Classic Congenital Adrenal Hyperplasia: Results from A Multiple-Dose Phase 2 Study

Introduction: Classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21OHD CAH) is a rare autosomal recessive disease that results in impaired cortisol synthesis and excess androgen production. Compounds that inhibit adrenocorticotropic hormone (ACTH) release could reduce adrenal androgen production and thus the amounts of exogenous glucocorticoids needed to decrease these androgen levels. This study evaluated the effect of crinecerfont (NBI-74788), a novel, non-steroidal, and selective corticotropin-releasing factor-1 (CRF1) receptor antagonist on adrenal androgens and precursors in adults with 21OHD CAH. Methods: This open-label, multiple-dose study enrolled men and women (18–50 years old) with 21OHD CAH. A sequential-cohort design evaluated 4 crinecerfont oral dosing regimens: 50 mg QHS (Cohort 1); 100 mg QHS (Cohort 2); 100 mg QD (Cohort 3); and 100 mg alternative dosing (Cohort 4). Each regimen was administered for 14 consecutive days. ACTH, 17-hydroxy-progesterone (17OHP), and androstenedione (A4) were measured serially over a 24-hour period, at baseline and after 14 days of dosing. Results: Analyses included 23 participants: Cohort 1 (4 women, 4 men: mean age 31.1 years); Cohort 2 (5 women, 2 men: mean age 32.9 years); and Cohort 3 (3 women, 5 men: mean age 30.9 years). Cohort 4 is ongoing. At baseline, median plasma ACTH, serum 17OHP, and serum A4 levels were as follows: Cohort 1 (ACTH, 151 pg/mL; 17OHP, 5352 ng/dL; A4, 270 ng/dL); Cohort 2 (ACTH, 232 pg/mL; 17OHP, 12821 ng/dL; A4, 597 ng/dL); and Cohort 3 (ACTH, 470 pg/mL; 17OHP, 6451 ng/dL; A4, 299 ng/dL). After 14 days of once-daily crinecerfont 50 mg, Cohort 1 patients had median percent reductions from baseline in plasma ACTH (-54%), serum 17OHP (-60%), and serum A4 (-21%). Median percent reductions were generally larger with 100 mg in Cohort 2 (ACTH, -67%; 17OHP, -75%; A4, -47%) and Cohort 3 (ACTH, -69%; 17OHP, -55%; A4, -43%), consistent with a dose-related response. Adverse events were mostly mild; no clinically significant findings from routine laboratory tests, vital signs, or electrocardiograms were noted. Conclusions: Results of this Phase 2 study of crinecerfont, a novel, orally administered, selective CRF1-receptor antagonist, indicated clinically meaningful reductions of elevated ACTH, 17OHP, and A4 in adults with 21OHD CAH after 14 days of treatment. Further studies are warranted to evaluate the effects of chronic crinecerfont therapy on maintenance of adrenal steroid production, clinical endpoints of disordered steroidogenesis, and reductions in GC exposure in both adult and pediatric patients with 21OHD CAH.

Elucidating the Anti‐Diuretic Hormone Signalling System of CAPA Neuropeptides in the Disease Vector Mosquito, Aedes aegypti

Blood‐feeding insects, including female Aedes aegypti mosquitoes, face the challenge of excess water and ion intake after a blood meal. To cope with this, insects have a highly active excretory system that includes the Malpighian ‘renal’ tubules (MTs), which are under rigorous control by several neuroendocrine factors. While endocrine regulation has been extensively studied in insects, most research has focused on the effects of diuretic hormones with limited study on anti‐diuretic hormones. Insect CAPA neuropeptides are produced in the central nervous system and are evolutionarily related to the vertebrate neuromedinU peptides. While CAPA peptides elicit distinct responses in different insect species, their activity on stimulated MTs in the adult A. aegypti remained unknown. Given the CAPA receptor is highly enriched in insect MTs, the objectives of this study were to examine the effects of a CAPA peptide on adult female MTs stimulated with various diuretic factors.The effect of endocrine factors on fluid secretion rate was measured using an in vitro bioassay where CAPA was found to inhibit secretion of MTs stimulated by select diuretic factors, 5‐HT and DH31, while having no effect on other diuretic factors, including kinin‐related and corticotropin releasing factor‐related (CRF) peptides. Although CAPA elicits strong anti‐diuretic activity, it does not influence the relative proportions of cations transported by adult MTs, thus maintaining the kaliuretic activity of 5‐HT and the natriuretic activity of DH31. Notably, the inhibitory effect of CAPA was abolished by knocking down the receptor using RNAi, verifying its critical role in anti‐diuresis. To investigate the signalling cascade mediating this anti‐diuretic effect, the second messenger cGMP was tested on adult MTs revealing that both 5‐HT and DH31–stimulated secretion is strongly inhibited by cGMP, similar to effects seen with CAPA. Pharmacological inhibition of PKG/NOS signalling abolishes the anti‐diuretic activity of CAPA, confirming the role of cGMP/PKG/NOS in the CAPA signalling pathway. Furthermore, MTs treated with bafilomycin, a V‐type H+‐ATPase inhibitor, was found to inhibit fluid secretion stimulated by 5‐HT and DH31, while having no inhibitory action on CRF‐stimulated MTs. Additionally, alkalization of the secreted fluid in response to CAPA suggests inhibition of the apical V‐type H+‐ATPase, which may lead to constrained entry of cations (Na+and K+) across the apical membrane of the MTs.A. aegypti mosquitoes are vectors of a variety of pathogens leading to diseases including Dengue fever and Zika virus. In this study, the importance of hormonal regulation of the MTs is demonstrated, analyzing the importance of both diuretic and anti‐diuretic hormones. Given the central importance of the MTs in insect biology, these insights will be useful considering the need to develop novel strategies or compounds which more specifically and efficiently reduce the burden of insect disease vectors.Support or Funding InformationSupported by an NSERC Discovery Grant (JPP), Petro Canada Young Innovator Award (JPP), Ontario Ministry of Research &amp; Innovation Early Researcher Award (JPP), NSERC Canada Graduate Scholarship (FS), Vernon Oliver Stong Graduate Scholarship in Science (FS), and The Carswell Scholarships in the Faculty of Science (FS)

Paeoniflorin regulates the hypothalamic-pituitary-adrenal axis negative feedback in a rat model of post-traumatic stress disorder.

Objective(s):To investigate the effects of paeoniflorin (PEF) on the hypothalamic-pituitary-adrenal (HPA) axis feedback function of post-traumatic stress disorder (PTSD). Materials and Methods:Single-prolonged stress (SPS) was used to establish a PTSD-like rat model. The contents of plasma corticosterone (CORT), adrenocorticotropin hormone (ACTH) and corticotropin-releasing hormone (CRH) were measured by ELISA. Glucocorticoid receptor (GR), mineralocorticoid receptor (MR), adrenocorticotropic hormone-releasing factor I receptor (CRF1R), and adrenocorticotropic hormone-releasing factor II receptor (CRF2R) in the hippocampus and amygdala were measured by RT-PCR and immunohistochemistry.Results:The results showed that on day 8 after SPS, model rats showed enhanced HPA axis negative feedback lasting to day 29. On day 29, plasma CORT levels increased in model rats, while plasma CRH levels had no significant difference on days 8, 22, and 29. The expression of GR and MR of model rats significantly increased in the hippocampus, while the expression of GR, MR, and CRF1R significantly decreased in the amygdala. After 14 days of continuous administration of PEF, the enhanced negative feedback was inhibited, and the plasma CORT level significantly reduced after 21 days of administration. Moreover, PEF could significantly decrease the expression of GR and MR in the hippocampus, and increase the expression of GR, MR, and CRF1R significantly in the amygdala. Conclusion:PEF could regulate HPA axis dysfunction in a rat model of PTSD, which may be related to regulating expression of GR and MR in the hippocampus and amygdala and regulating expression of CRF1R in the amygdala.

Molecular Basis for Hormone Recognition and Activation of Corticotropin-Releasing Factor Receptors.

Corticotropin-releasing factor (CRF) and the three related peptides urocortins 1-3 (UCN1-UCN3) are endocrine hormones that control the stress responses by activating CRF1R and CRF2R, two members of class B G-protein-coupled receptors (GPCRs). Here, we present two cryoelectron microscopy (cryo-EM) structures of UCN1-bound CRF1R and CRF2R with the stimulatory G protein. In both structures, UCN1 adopts a single straight helix with its N terminus dipped into the receptor transmembrane bundle. Although the peptide-binding residues in CRF1R and CRF2R are different from other members of class B GPCRs, the residues involved in receptor activation and G protein coupling are conserved. In addition, both structures reveal bound cholesterol molecules to the receptor transmembrane helices. Our structures define the basis of ligand-binding specificity in the CRF receptor-hormone system, establish a common mechanism of class B GPCR activation and G protein coupling, and provide a paradigm for studying membrane protein-lipid interactions for class B GPCRs.

НЕЙРОМОДУЛЯТОРНАЯ ЛИГАНД-РЕЦЕПТОРНАЯ СИСТЕМА TIP39-PTH2R

Widely spread axon terminals of TIP39 neurons have a distribution similar to PTH2R containing neurons and their fibers which provides an anatomic base of neuromodulation action of TIP39. This functional and anatomic link- ing lets state that TIP39 and PTH2R form a neuromodulator ligand-receptor system. Basing on mechanisms of signal transmission used by TIP39 and PTH2R, they can form a neuromodulator system in many brain parts. TIP39-PTH2R system is a unique neuropeptide-receptor system, which localization and functions in the central nervous system differ from any other neuropeptides. Neuromodulator system TIP39-PTH2R predominantly participates in neuroendocrinal modulation by affecting the endocrinal system by means of its presence in several areas of hypothalamus. TIP39 influences neurons that contain somatostatin and corticotropin-releasing hormone. TIP39 can affect the release of adrenocorticotropin, luteinizing hormone, growth hormone and arginine-vasopressin from hypophysis. Experimental data prove that TIP39 modulates regulatory network of anxiety and depression, several aspects of stress reaction and also controls body temperature, participates in processing of auditory and nociceptive information. Physiological role of TIP39-PTH2R system is still to some extent unknown. However, distribution of PTH2R and TIP39 in tissues outside central nervous system assumes other potential physiological effects for this signal way. It is assumed that TIP39- PTH2R system should be probably considered as a potential therapeutic target for treatment of anxiety, depression and chronic pain, control and correction of neuroendocrine disruptions.

Sex differences in ultrasonic vocalization and hormonal stress response of an anxious mice strain during the early postnatal period

Development of anxiolytics requires animal models; therefore anxious (AX) and nonanxious (nAX) mice have been selectively bred based upon their adult behaviour in reaction to handling. Since inadequate response to postnatal challenges may have lifelong consequences, we aimed to determine whether alterations in postnatal stress-coping may contribute to the state of anxiety in adult AX mice. Maternal separation-induced ultrasonic vocalization (MS-USV) was studied in one-week-old nAX-AX mice and one week later the endocrine stress response was measured after lipopolysaccharide (LPS) stimulation, a model of bacterial infection, with special focus on sex differences. It was established that AX females produced a significantly lower frequency and duration of MS-USV than nAX female mice. USV emitted by AX males showed only a tendency to be reduced compared to nAX males. LPS injection generated a significantly increased adrenocorticotropin release in nAX mice only and with no sex-related difference observed. Resting corticosterone levels were higher in AX mice compared to nAX, however, this difference reached the level of significance only in females. LPS-injection was able to induce significant corticosterone elevation with markedly higher levels in AX females than nAX females. To sum up, we conclude that females are more susceptible to the influence of stressors during the early postnatal period, as they exhibited more pronounced reactions. The adult state anxiety of the strain was not paralleled by MS-USV during the perinatal period. Thus, the question arises if MS-USV indeed reflects anxiety only. According to our expectation, AX animals had higher baseline stress-hormone levels, but their reactivity to stressors was altered, which may have contributed to their supposed adult phenotype.

Vasopressin Receptor Antagonists (Vaptans) in Heart Failure

Arginine vasopressin (a peptide neuroendocrine hormone) levels are elevated in patients with HF. Acting through 3 receptor subtypes, it can cause vasoconstriction and cardiac remodelling (receptors V1a), adrenocorticotropic hormone release (receptors V1b) and water reabsorption (receptors V2), thereby increasing preload and afterload. Vasopressin-receptor antagonists (vaptans), induce hypotonic diuresis and have been proposed as a treatment option for hyponatraemia, a known complication of HF. Three vaptans have been so tested; tolvaptan, conivaptan and lixivaptan, and two (tolvaptan and conivaptan) have been approved for clinical use in hyponatraemia (in the USA). The EVEREST trial studied tolvaptan in over 4100 patients hospitalized with an exacerbation of chronic HF with reduced LVEF. No effect was seen on long-term mortality or HF-related morbidity, but there was greater weight loss and better dyspnoea and oedema relief over the short-term. Similar results were seen in the AQUAMARINE study. The 2016 European HF guidelines, therefore gave the limited recommendation: “Tolvaptan may be used to treat patients with volume overload and resistant hyponatraemia”. Despite targeting an attractive therapeutic target, vasopressin receptor antagonists (vaptans) have to date played only a minor role in our management of HF.

THE ROLE OF ENDORPHIN HORMONES AS PREDICTORS OF PREGNANCY ANXIETY

Pregnancy anxiety is a common problem with a prevalence of 14-54% and is the highest in the third trimester. Pregnancy anxiety is associated with neurotransmitter dysregulation and endocrine changes in the Hypothalamus Pituitary Adrenal (HPA) axis pathway through the increase of synthesis and the release of corticotropin-releasing hormone (CRH), Adrenocorticotropic Hormone (ACTH) and cortisol to suppress endorphin hormone production. This study aims to determine the relationship of endorphin hormone levels to pregnancy anxiety. This study was an observational study using a cross-sectional approach to 57 pregnant women. The anxiety level was measured by using the Hamilton Anxiety Rating Scale (HARS) and the ELISA kit with plasma specimens was employed to examine the endorphin hormone levels. The results showed that endorphin hormone levels acted as predictors of pregnancy anxiety (p = 0,000).&#x0D; Keywords: Anxiety, Pregnancy, Endorphin&#x0D;

A Retrospective Observational Study of the Neuroendocrine Stress Response in Patients Undergoing Endoscopic Transsphenoidal Surgery for Removal of Pituitary Adenomas: Total Intravenous Versus Balanced Anesthesia.

Anesthetic technique affects the neuroendocrine stress response to surgery. In this retrospective study, we compared the neuroendocrine stress response in patients undergoing endoscopic transsphenoidal pituitary adenoma surgery (ETSPAS) with total intravenous anesthesia (TIVA) with propofol-remifentanil or balanced anesthesia (BAL) with sevoflurane-remifentanil. Eighty-nine patients undergoing ETSPAS were anesthetized with either propofol-remifentanil (TIVA group, n=62) or sevoflurane-remifentanil (BAL group, n=27). Data were retrospectively collected regarding preoperative and immediate postoperative serum levels of adrenocorticotropic hormone (ACTH) and cortisol (primary outcome measures), as well as other pituitary hormones and their target organ hormones (secondary outcome measures). There were no significant differences in preoperative pituitary hormone levels between the 2 groups. The immediate postoperative ACTH (89.5 [62.1 to 162.6] vs. 256.0 [92.0 to 570.7] pg/mL; P<0.001) level was lower in the TIVA group than in the BAL group, whereas immediate postoperative cortisol levels were similar between the 2 groups. The immediate postoperative thyroid-stimulating hormone (1.85 [1.21 to 2.98] vs. 1.21 [0.44 to 1.71] μIU/mL; P=0.003), triiodothyronine (91.0 [82.0 to 103.0] vs. 69.1 [64.6 to 76.2] ng/dL; P<0.001), luteinizing hormone (2.2 [1.2 to 4.0] vs. 1.0 [0.5 to 2.3] mIU/mL; P=0.005), and prolactin (22.6±15.8 vs. 12.8±10.2 ng/mL; P=0.005) levels were higher in the TIVA group compared with the BAL group. In both groups, none of the patients who had sufficient preoperative ACTH without hydrocortisone supplementation (n=15) showed hypocortisolism in the immediate postoperative measurement. Compared with BAL, TIVA resulted in reduced release of ACTH and increased release of thyroid-stimulating hormone, triiodothyronine, luteinizing hormone, and prolactin in patients undergoing ETSPAS.

Stress and reproduction in farm animals

Transport of post-partum cows or sheep before an oestradiol-induced LH surge delayed gonadotrophin secretion possibly by affecting hypothalamic activity but not via an opioid mediated mechanism as the effect could not be reversed by naloxone. In addition, reduced LH responses to GnRH were observed in cattle during transport. In sheep, adrenocorticotrophic hormone (ACTH) also diminished the LH response to GnRH, but only when GnRH was administered 3 h after ACTH, not after 0.5 h. This finding suggests that very early suppression of LH secretion by stressors is not mediated by ACTH action at the pituitary but that immediate activation of the sympathetic nervous system may be involved. In ewes during the breeding season, repeated exposure to GnRH at intervals of 2 h during transport resulted in lower LH responses to the second and third injections. When anoestrous ewes were treated with oestradiol and GnRH while being restrained and isolated, the onset of the LH surge was delayed. The effects of hypothalamus-pituitary-adrenal hyperactivity on LH release may involve suppression of GnRH receptor activity, a reduction in releasable LH, or both factors. Studies in vitro with perifused ovine pituitaries showed that ACTH or corticotrophin releasing hormone markedly suppressed LH secretion in response to the second of two exposures to GnRH. This occurred with pituitaries obtained from anoestrous ewes irrespective of prior treatment with oestradiol, suggesting that compounds from the hypothalamus-pituitary-adrenal do not exert effects on the oestradiol-sensitizing mechanisms on the pituitary. In conclusion, stressors affect reproductive function via actions at the hypothalamus as well as impairing pituitary LH release induced by GnRH.

Commentary on "Sex differences in the effect of cannabinoid type 1 receptor deletion on locus coeruleus-norepinephrine neurons and corticotropin releasing factor-mediated responses".

Commentary on "Sex differences in the effect of cannabinoid type 1 receptor deletion on locus coeruleus-norepinephrine neurons and corticotropin releasing factor-mediated responses".

Abstract # 3118 Acylated ghrelin’s anti-inflammatory actions on lipopolysaccharide (LPS)-induced cytokine release

Ghrelin regulates hypothalamic-pituitary-adrenal (HPA) axis responses to psychological stress at the brain and pituitary. Ghrelin is also a potent anti-inflammatory agent. However, its role in the HPA axis response to immune challenge is still imprecisely described. We hypothesized ghrelin’s anti-inflammatory actions on lipopolysaccharide (LPS)-induced cytokine release are mediated by activation of the HPA axis. We gave Wistar rats acylated ghrelin (AG; 1 mg/kg sc), concomitantly with lipopolysaccharide (LPS; E. coli, 100 μ g/kg i.p.) or pyrogen-free saline. We then assessed circulating cytokines and paraventricular nucleus of the hypothalamus (PVN) neuronal activation (c-Fos) as well as glucocorticoid and adrenocorticotropic hormone (ACTH) profiles. Our data show that AG markedly suppresses the circulating cytokine response to LPS, particularly that of tumour necrosis factor alpha, interleukin 1 and interleukin 10. In vitro, high AG can stimulate release of ACTH from the anterior pituitary, but in vivo the ACTH and glucocorticoid responses to LPS are not influenced by AG. AG alone activates the medial parvocellular region of the PVN, but it does not alter the LPS-induced activation of this region. These data suggest that AG markedly suppresses the circulating cytokine response to LPS but probably does not do this by modulating the HPA axis response in vivo.

Gender-based relationship between copeptin level and metabolic syndrome in Albino rats

Background: Arginine vasopressin (AVP) affects liver glycogenolysis, insulin, and adrenocorticotropic hormone release supporting its role in metabolic disorders. Copeptin is established as a stable and sensitive biomarker of AVP level. Aims and Objectives: The aim of the study is to investigate the association between serum copeptin level and metabolic syndrome (MetS) parameters in both male and female albino rats. Materials and Methods: Sixteen male and 16 female adult rats were subdivided into control and high-carbohydrate high-fat (HCHF)-fed groups. Body mass index (BMI), systolic, diastolic, and mean arterial blood pressure (MABP) were measured. Serum total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), glucose, insulin, highly sensitive C-reactive protein (hs-CRP), and copeptin were estimated. Homeostatic model assessment for insulin resistance (HOMA-IR) and atherogenic index (AI) were calculated. Results: There was significant increase in BMI, blood pressures, and levels of TC, TG, LDL-C, AI, glucose, insulin, HOMA-IR, hs-CRP, and copeptin with significant decrease in HDL-C level in male and female HCHF-fed groups compared with their controls. All parameters except HDL-C, blood pressures, and hs-CRP were significantly lower in female HCHF-fed group compared with male HCHF-fed one. There was positive correlation between copeptin level and BMI, insulin, glucose, HOMA-IR, TC, TG, LDL-C, AI, and hs-CRP and negative correlation with HDL-C with insignificant correlation with MABP in both HCHF groups. Conclusion: HCHF-fed male rats are more subjected to develop features of MetS with more elevation in copeptin than female rats. Elevated copeptin was correlated with components of MetS as obesity, hyperglycemia, IR, dyslipidemia, and hs-CRP in both sexes indicating the role of the vasopressinergic system in the pathogenesis of MetS. Further studies to evaluate copeptin as a predictive marker for MetS and therapeutic role of controlling AVP based on gender difference are recommended.

Effects of biological factors on the expression of arginine vasopressin receptors

Arginine vasopressin (AVP) is a hormone that functions to regulate blood pressure and bodily fluid homeostasis. Vasopressin has three main receptors AVPR1a, AVPR1b, and AVPR2 which were investigated in this project along with OXTR, LNPEP, and CUL5. AVPR1a functions in the smooth muscle and causes vasoconstriction, AVPR1b functions in the pituitary helping to regulate adrenocorticotropic hormone release, and AVPR2 is expressed highly in the kidneys and works to concentrate urine. This project investigates how these various receptors are expressed with different factors related to pregnancy such as, sex of the baby, chronically hypertensive mothers, and gestational age at delivery

Sex differences in the effect of cannabinoid type 1 receptor deletion on locus coeruleus-norepinephrine neurons and corticotropin releasing factor-mediated responses.

Cannabinoids are capable of modulating mood, arousal, cognition and behavior, in part via their effects on the noradrenergic nucleus locus coeruleus (LC). Dysregulation of LC signaling and norepinephrine (NE) efflux in the medial prefrontal cortex (mPFC) can lead to the development of psychiatric disorders, and CB1r deletion results in alterations of α2- and β1-adrenoceptors in the mPFC, suggestive of increased LC activity. To determine how CB1r deletion alters LC signaling, whole-cell patch-clamp electrophysiology was conducted in LC-NE neurons of male and female wild type (WT) and CB1r-knock out (KO) mice. CB1r deletion caused a significant increase in LC-NE excitability and input resistance in male but not female mice when compared to WT. CB1r deletion also caused adaptations in several indices of noradrenergic function. CB1r/CB2r-KO male mice had a significant increase in cortical NE levels and tyrosine hydroxylase and CRF levels in the LC compared to WT males. CB1r/CB2r-KO female mice showed a significant increase in LC α2-AR levels compared to WT females. To further probe actions of the endocannabinoid system as an anti-stress neuromediator, the effect of CB1r deletion on CRF-induced responses in the LC was investigated. The increase in LC-NE excitability observed in male and female WT mice following CRF (300nM) bath application was not observed in CB1r-KO mice. These results indicate that cellular adaptations following CB1r deletion cause a disruption in LC-NE signaling in males but not females, suggesting underlying sex differences in compensatory mechanisms in KO mice as well as basal endocannabinoid regulation of LC-NE activity.

The Role of Uron and Chlorobenzene Derivatives, as Potential Endocrine Disrupting Compounds, in the Secretion of ACTH and PRL.

Uron herbicides polluting the environment represent a serious concern for environmental health and may be regarded as endocrine-disrupting compounds (EDCs), which influence the regulation of human homeostasis. We aimed to investigate the effect of EDC urons (phenuron: PU, monuron: MU, and diuron: DU) and chlorobenzenes on the basal release of the adrenocorticotropic hormone (ACTH), which is a part of the adenohypophysis-adrenocortical axis. Hormone secretion in the presence of EDC was studied in two cell types: normal adenohypophysis cells (AdH) and cells of prolactinomas (PRLOMA). PRLOMA was induced in female Wistar rats by subcutaneously injecting them with estrone acetate for 6 months. AdH and PRLOMA were separated from treated and untreated experimental animals, dissociated enzymatically and mechanically in order to create monolayer cell cultures, which served as an experimental in vitro model. We investigated the effects of ED agents separately and in combination on ACTH and prolactin (PRL) release through the hypophyseal-adrenal axis. Hormone determination was carried out by the luminescent immunoassay and the radioimmunoassay methods. Our results showed that (1) uron agents separately did not change ACTH and PRL release in AdH culture; (2) ACTH secretion in arginine vasopressin- (AVP-) activated AdH cells was significantly increased by EDC treatment; (3) ED agents increased the basal hormone release (ACTH, PRL) in PRLOMA cells; and (4) EDC exposure increased ACTH release in AVP-activated PRLOMA cells. We conclude that the herbicides PU, MU, and DU carry EDC effects and show human toxicity potential.