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Ehresman E, Curtis K. Estradiol modulation of behavioral and physiological body fluid control during repeated dietary sodium deprivation. Physiol Behav 2024; 273:114400. [PMID: 37924964 DOI: 10.1016/j.physbeh.2023.114400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/21/2023] [Accepted: 11/01/2023] [Indexed: 11/06/2023]
Abstract
The low salt diet is a first line treatment for hypertension, but it is a difficult diet to maintain. As a result, patients may alternate between periods of high and low salt intake, the effects of which are unclear. Importantly, blood pressure increases in women after menopause, suggesting that estrogen plays a role in preventing hypertension. At present, however, it is unknown if the behavioral and physiological impact of alternating episodes on the low salt diet may be altered by the presence of estrogen. Our goals were to assess salt intake and body fluid hormones with repeated dietary sodium deprivations. Using ovariectomized rats with (EB) and without (OIL) estrogen treatment, we subjected rats to one or two dietary sodium deprivations using low salt laboratory chow. 0.5 M NaCl and water intakes were recorded after each period of regular chow or deprivation. After deprivation, rats were sacrificed, and trunk blood was collected for analysis of vasopressin, norepinephrine, epinephrine, and aldosterone levels. Plasma sodium concentration, plasma protein concentration, body weight, and uterine weight were also measured. There was no difference in the salt intakes of OIL- or EB-treated rats after one or two dietary sodium deprivations. However, EB-treated rats drank a less concentrated solution overall, suggesting less overcompensation after dietary sodium deprivation. Additionally, after a single episode of dietary sodium deprivation, EB-treated rats' consumption remained elevated above baseline even after returning to regular laboratory chow. These behavioral differences were not explained by alterations in vasopressin, norepinephrine, epinephrine, or aldosterone. Plasma sodium and plasma protein concentrations also did not show alterations related to the change in behavior. Further research is necessary to determine the mechanism behind these changes in intake in EB-treated rats, which may ultimately be clinically relevant for both pre- and postmenopausal women on the low salt diet.
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Affiliation(s)
- Emily Ehresman
- Oklahoma State University Center for Health Sciences, 1111 W 17th St, Tulsa, OK, 74107, USA.
| | - Kathleen Curtis
- Oklahoma State University Center for Health Sciences, 1111 W 17th St, Tulsa, OK, 74107, USA
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2
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Grassi D, Marraudino M, Garcia-Segura LM, Panzica GC. The hypothalamic paraventricular nucleus as a central hub for the estrogenic modulation of neuroendocrine function and behavior. Front Neuroendocrinol 2022; 65:100974. [PMID: 34995643 DOI: 10.1016/j.yfrne.2021.100974] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 12/18/2021] [Accepted: 12/21/2021] [Indexed: 12/17/2022]
Abstract
Estradiol and hypothalamic paraventricular nucleus (PVN) help coordinate reproduction with body physiology, growth and metabolism. PVN integrates hormonal and neural signals originating in the periphery, generating an output mediated both by its long-distance neuronal projections, and by a variety of neurohormones produced by its magnocellular and parvocellular neurosecretory cells. Here we review the cyto-and chemo-architecture, the connectivity and function of PVN and the sex-specific regulation exerted by estradiol on PVN neurons and on the expression of neurotransmitters, neuromodulators, neuropeptides and neurohormones in PVN. Classical and non-classical estrogen receptors (ERs) are expressed in neuronal afferents to PVN and in specific PVN interneurons, projecting neurons, neurosecretory neurons and glial cells that are involved in the input-output integration and coordination of neurohormonal signals. Indeed, PVN ERs are known to modulate body homeostatic processes such as autonomic functions, stress response, reproduction, and metabolic control. Finally, the functional implications of the estrogenic modulation of the PVN for body homeostasis are discussed.
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Affiliation(s)
- D Grassi
- Department of Anatomy, Histology and Neuroscience, Universidad Autonoma de Madrid, Madrid, Spain
| | - M Marraudino
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano, Torino, Italy
| | - L M Garcia-Segura
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - G C Panzica
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano, Torino, Italy; Department of Neuroscience Rita Levi Montalcini, University of Torino, Torino, Italy.
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3
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Balapattabi K, Little JT, Bachelor ME, Cunningham RL, Cunningham JT. Sex Differences in the Regulation of Vasopressin and Oxytocin Secretion in Bile Duct-Ligated Rats. Neuroendocrinology 2020; 111:237-248. [PMID: 32335554 PMCID: PMC7584765 DOI: 10.1159/000508104] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 04/23/2020] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Hyponatremia due to elevated arginine vasopressin (AVP) secretion increases mortality in liver failure patients. No previous studies have addressed sex differences in hyponatremia in liver failure animal models. OBJECTIVE This study addressed this gap in our understanding of the potential sex differences in hyponatremia associated with increased AVP secretion. METHODS This study tested the role of sex in the development of hyponatremia using adult male, female, and ovariectomized (OVX) female bile duct-ligated (BDL) rats. RESULTS All BDL rats had significantly increased liver to body weight ratios compared to sham controls. Male BDL rats had hyponatremia with significant increases in plasma copeptin and FosB expression in supraoptic AVP neurons compared to male shams (all p < 0.05; 5-7). Female BDL rats did not become hyponatremic or demonstrate increased supraoptic AVP neuron activation and copeptin secretion compared to female shams. Plasma oxytocin was significantly higher in female BDL rats compared to female sham (p < 0.05; 6-10). This increase was not observed in male BDL rats. Ovariectomy significantly decreased plasma estradiol in sham rats compared to intact female sham (p < 0.05; 6-10). However, circulating estradiol was significantly elevated in OVX BDL rats compared to the OVX and female shams (p < 0.05; 6-10). Adrenal estradiol, testosterone, and dehydroepiandrosterone (DHEA) were measured to identify a possible source of circulating estradiol in OVX BDL rats. The OVX BDL rats had significantly increased adrenal estradiol along with significantly decreased adrenal testosterone and DHEA compared to OVX shams (all p < 0.05; 6-7). Plasma osmolality, hematocrit, copeptin, and AVP neuron activation were not significantly different between OVX BDL and OVX shams. Plasma oxytocin was significantly higher in OVX BDL rats compared to OVX sham. CONCLUSIONS Our results show that unlike male BDL rats, female and OVX BDL rats did not develop hyponatremia, supraoptic AVP neuron activation, or increased copeptin secretion compared to female shams. Adrenal estradiol might have compensated for the lack of ovarian estrogens in OVX BDL rats.
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Affiliation(s)
- Kirthikaa Balapattabi
- Department of Physiology and Anatomy, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, USA
| | - Joel T Little
- Department of Physiology and Anatomy, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, USA
| | - Martha E Bachelor
- Department of Physiology and Anatomy, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, USA
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, USA
| | - J Thomas Cunningham
- Department of Physiology and Anatomy, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, USA,
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Lagunas N, Marraudino M, de Amorim M, Pinos H, Collado P, Panzica G, Garcia-Segura LM, Grassi D. Estrogen receptor beta and G protein-coupled estrogen receptor 1 are involved in the acute estrogenic regulation of arginine-vasopressin immunoreactive levels in the supraoptic and paraventricular hypothalamic nuclei of female rats. Brain Res 2019; 1712:93-100. [DOI: 10.1016/j.brainres.2019.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/01/2019] [Accepted: 02/03/2019] [Indexed: 01/20/2023]
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Yohn CN, Leithead AB, Ford J, Gill A, Becker EA. Paternal Care Impacts Oxytocin Expression in California Mouse Offspring and Basal Testosterone in Female, but Not Male Pups. Front Behav Neurosci 2018; 12:181. [PMID: 30210315 PMCID: PMC6123359 DOI: 10.3389/fnbeh.2018.00181] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/02/2018] [Indexed: 12/20/2022] Open
Abstract
Natural variations in parenting are associated with differences in expression of several hormones and neuropeptides which may mediate lasting effects on offspring development, like regulation of stress reactivity and social behavior. Using the bi-parental California mouse, we have demonstrated that parenting and aggression are programmed, at least in part, by paternal behavior as adult offspring model the degree of parental behavior received in development and are more territorial following high as compared to low levels of care. Development of these behaviors may be driven by transient increases in testosterone following paternal retrievals and increased adult arginine vasopressin (AVP) immunoreactivity within the bed nucleus of the stria terminalis (BNST) among high-care (HC) offspring. It remains unclear, however, whether other neuropeptides, such as oxytocin (OT), which is sensitive to gonadal steroids, are similarly impacted by father-offspring interactions. To test this question, we manipulated paternal care (high and low care) and examined differences in adult offspring OT-immunoreactive (OT-ir) within social brain areas as well as basal T and corticosterone (Cort) levels. HC offspring had more OT-ir within the paraventricular nucleus (PVN) and supraoptic nucleus (SON) than low-care (LC) offspring. Additionally, T levels were higher among HC than LC females, but no differences were found in males. There were no differences in Cort indicating that our brief father-pup separations likely had no consequences on stress reactivity. Together with our previous work, our data suggest that social behavior may be programmed by paternal care through lasting influences on the neuroendocrine system.
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Affiliation(s)
- Christine N Yohn
- Department of Psychology, Saint Joseph's University, Philadelphia, PA, United States.,Department of Psychology, Rutgers University, Piscataway, NJ, United States
| | - Amanda B Leithead
- Department of Psychology, Saint Joseph's University, Philadelphia, PA, United States
| | - Julian Ford
- Department of Psychology, Saint Joseph's University, Philadelphia, PA, United States
| | - Alexander Gill
- Department of Psychology, Saint Joseph's University, Philadelphia, PA, United States
| | - Elizabeth A Becker
- Department of Psychology, Saint Joseph's University, Philadelphia, PA, United States
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6
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Yohn CN, Leithead AB, Ford J, Gill A, Becker EA. Paternal Care Impacts Oxytocin Expression in California Mouse Offspring and Basal Testosterone in Female, but Not Male Pups. Front Behav Neurosci 2018. [PMID: 30210315 DOI: 10.3389/fnbeh.2018.00181/bibtex] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
Abstract
Natural variations in parenting are associated with differences in expression of several hormones and neuropeptides which may mediate lasting effects on offspring development, like regulation of stress reactivity and social behavior. Using the bi-parental California mouse, we have demonstrated that parenting and aggression are programmed, at least in part, by paternal behavior as adult offspring model the degree of parental behavior received in development and are more territorial following high as compared to low levels of care. Development of these behaviors may be driven by transient increases in testosterone following paternal retrievals and increased adult arginine vasopressin (AVP) immunoreactivity within the bed nucleus of the stria terminalis (BNST) among high-care (HC) offspring. It remains unclear, however, whether other neuropeptides, such as oxytocin (OT), which is sensitive to gonadal steroids, are similarly impacted by father-offspring interactions. To test this question, we manipulated paternal care (high and low care) and examined differences in adult offspring OT-immunoreactive (OT-ir) within social brain areas as well as basal T and corticosterone (Cort) levels. HC offspring had more OT-ir within the paraventricular nucleus (PVN) and supraoptic nucleus (SON) than low-care (LC) offspring. Additionally, T levels were higher among HC than LC females, but no differences were found in males. There were no differences in Cort indicating that our brief father-pup separations likely had no consequences on stress reactivity. Together with our previous work, our data suggest that social behavior may be programmed by paternal care through lasting influences on the neuroendocrine system.
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Affiliation(s)
- Christine N Yohn
- Department of Psychology, Saint Joseph's University, Philadelphia, PA, United States
- Department of Psychology, Rutgers University, Piscataway, NJ, United States
| | - Amanda B Leithead
- Department of Psychology, Saint Joseph's University, Philadelphia, PA, United States
| | - Julian Ford
- Department of Psychology, Saint Joseph's University, Philadelphia, PA, United States
| | - Alexander Gill
- Department of Psychology, Saint Joseph's University, Philadelphia, PA, United States
| | - Elizabeth A Becker
- Department of Psychology, Saint Joseph's University, Philadelphia, PA, United States
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7
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Gordon I, Pratt M, Bergunde K, Zagoory-Sharon O, Feldman R. Testosterone, oxytocin, and the development of human parental care. Horm Behav 2017; 93:184-192. [PMID: 28576647 DOI: 10.1016/j.yhbeh.2017.05.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 05/17/2017] [Accepted: 05/28/2017] [Indexed: 11/30/2022]
Abstract
The steroid testosterone (T) and neuropeptide oxytocin (OT) have each been implicated in the development of parental care in humans and animals, yet very little research addressed the interaction between these hormones at the transition to parenthood in mothers and fathers. One hundred and sixty mothers and fathers (80 couples) were visited 1 and 6months after the birth of their first child, plasma OT and T were assayed at each time-point, and interactions between each parent and the infant were observed and micro-coded for two key parental behaviors; affectionate touch and parent-infant synchrony. T showed gender-specific effects. While paternal T was individually stable across the first six months of parenting and predicted lower father-infant synchrony, maternal T was neither stable nor predictive of maternal behavior. An interaction of OT and T showed that T has complex modulatory effects on the relations of OT and parenting. Slope analysis revealed that among fathers, only when T was high (+1SD), negative associations emerged between OT and father affectionate touch. In contrast, among mothers, the context of high T was related to a positive association between OT and maternal touch. Our findings, the first to test the interaction of OT and T in relation to observed maternal behavior, underscore the need for much further research on the complex bidirectional effects of steroid and neuropeptide systems on human mothering and fathering.
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Affiliation(s)
- Ilanit Gordon
- Bar Ilan University, Israel; Yale University, United States.
| | | | | | | | - Ruth Feldman
- Bar Ilan University, Israel; Yale University, United States
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8
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Banerjee P, Joy KP, Chaube R. Structural and functional diversity of nonapeptide hormones from an evolutionary perspective: A review. Gen Comp Endocrinol 2017; 241:4-23. [PMID: 27133544 DOI: 10.1016/j.ygcen.2016.04.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 04/09/2016] [Accepted: 04/25/2016] [Indexed: 01/08/2023]
Abstract
The article presents an overview of the comparative distribution, structure and functions of the nonapeptide hormones in chordates and non chordates. The review begins with a historical preview of the advent of the concept of neurosecretion and birth of neuroendocrine science, pioneered by the works of E. Scharrer and W. Bargmann. The sections which follow discuss different vertebrate nonapeptides, their distribution, comparison, precursor gene structures and processing, highlighting the major differences in these aspects amidst the conserved features across vertebrates. The vast literature on the anatomical characteristics of the nonapeptide secreting nuclei in the brain and their projections was briefly reviewed in a comparative framework. Recent knowledge on the nonapeptide hormone receptors and their intracellular signaling pathways is discussed and few grey areas which require deeper studies are identified. The sections on the functions and regulation of nonapeptides summarize the huge and ever increasing literature that is available in these areas. The nonapeptides emerge as key homeostatic molecules with complex regulation and several synergistic partners. Lastly, an update of the nonapeptides in non chordates with respect to distribution, site of synthesis, functions and receptors, dealt separately for each phylum, is presented. The non chordate nonapeptides share many similarities with their counterparts in vertebrates, pointing the system to have an ancient origin and to be an important substrate for changes during adaptive evolution. The article concludes projecting the nonapeptides as one of the very first common molecules of the primitive nervous and endocrine systems, which have been retained to maintain homeostatic functions in metazoans; some of which are conserved across the animal kingdom and some are specialized in a group/lineage-specific manner.
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Affiliation(s)
- P Banerjee
- Department of Zoology, Centre of Advanced Study, Banaras Hindu University, Varanasi 221005, India
| | - K P Joy
- Department of Biotechnology, Cochin University of Science and Technology, Kochi 682022, India.
| | - R Chaube
- Department of Zoology, Centre of Advanced Study, Banaras Hindu University, Varanasi 221005, India
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9
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Pineda R, Sabatier N, Ludwig M, Millar RP, Leng G. A Direct Neurokinin B Projection from the Arcuate Nucleus Regulates Magnocellular Vasopressin Cells of the Supraoptic Nucleus. J Neuroendocrinol 2016; 28. [PMID: 26610724 DOI: 10.1111/jne.12342] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 11/02/2015] [Accepted: 11/22/2015] [Indexed: 01/11/2023]
Abstract
Central administration of neurokinin B (NKB) agonists stimulates immediate early gene expression in the hypothalamus and increases the secretion of vasopressin from the posterior pituitary through a mechanism that depends on the activation of neurokinin receptor 3 receptors (NK3R). The present study reports that, in the rat, immunoreactivity for NK3R is expressed in magnocellular vasopressin and oxytocin neurones in the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus, and that NKB immunoreactivity is expressed in fibres in close juxtaposition with vasopressin neurones at both of these sites. Retrograde tracing in the rat shows that some NKB-expressing neurones in the arcuate nucleus project to the SON and, in mice, using an anterograde tracing approach, it is found that kisspeptin-expressing neurones of the arcuate nucleus, which are known to co-express NKB, project to the SON and PVN. Finally, i.c.v. injection of the NK3R agonist senktide is shown to potently increase the electrical activity of vasopressin neurones in the SON in vivo with no significant effect detected on oxytocin neurones. The results suggest that NKB-containing neurones in the arcuate nucleus regulate the secretion of vasopressin from magnocellular neurones in rodents, and the possible significance of this is discussed.
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Affiliation(s)
- R Pineda
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - N Sabatier
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - M Ludwig
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - R P Millar
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
- MRC Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - G Leng
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
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10
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Grassi D, Ghorbanpoor S, Acaz-Fonseca E, Ruiz-Palmero I, Garcia-Segura LM. The Selective Estrogen Receptor Modulator Raloxifene Regulates Arginine-Vasopressin Gene Expression in Human Female Neuroblastoma Cells Through G Protein-Coupled Estrogen Receptor and ERK Signaling. Endocrinology 2015. [PMID: 26200092 DOI: 10.1210/en.2014-2010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The selective estrogen receptor modulator raloxifene reduces blood pressure in hypertensive postmenopausal women. In the present study we have explored whether raloxifene regulates gene expression of arginine vasopressin (AVP), which is involved in the pathogenesis of hypertension. The effect of raloxifene was assessed in human female SH-SY5Y neuroblastoma cells, which have been recently identified as a suitable cellular model to study the estrogenic regulation of AVP. Raloxifene, within a concentration ranging from 10(-10) M to 10(-6) M, decreased the mRNA levels of AVP in SH-SY5Y cells with maximal effect at 10(-7) M. This effect of raloxifene was imitated by an agonist (±)-1-[(3aR*,4S*,9bS*)-4-(6-bromo-1,3-benzodioxol-5-yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinolin-8-yl]-ethanone of G protein-coupled estrogen receptor-1 (GPER) and blocked by an antagonist (3aS*,4R*,9bR*)-4-(6-bromo-1,3-benzodioxol-5-yl)-3a,4,5,9b-3H-cyclopenta[c]quinoline of GPER and by GPER silencing. Raloxifene induced a time-dependent increase in the level of phosphorylated ERK1 and ERK2, by a mechanism blocked by the GPER antagonist. The treatment of SH-SY5Y cells with either a MAPK/ERK kinase 1/2-specific inhibitor (1,4-diamino-2, 3-dicyano-1,4-bis(2-aminophenylthio)butadine) or a protein kinase C inhibitor (sotrastaurin) blocked the effects of raloxifene on the phosphorylation of ERK1/2 and the regulation of AVP mRNA levels. These results reveal a mechanism mediating the regulation of AVP expression by raloxifene, involving the activation of GPER, which in turn activates protein kinase C, MAPK/ERK kinase, and ERK. The regulation of AVP by raloxifene and GPER may have implications for the treatment of blood hypertension(.).
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Affiliation(s)
- Daniela Grassi
- Instituto Cajal (D.G., S.G., E.A.-F., I.R.P., L.M.G.-S.), Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain; Institute of Anatomy and Cell Biology (D.G.), Department of Molecular Embryology, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany; and Department of Cell and Molecular Biology (S.G.), School of Biology, College of Science, University of Tehran, 14155-6455 Tehran, Iran
| | - Samar Ghorbanpoor
- Instituto Cajal (D.G., S.G., E.A.-F., I.R.P., L.M.G.-S.), Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain; Institute of Anatomy and Cell Biology (D.G.), Department of Molecular Embryology, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany; and Department of Cell and Molecular Biology (S.G.), School of Biology, College of Science, University of Tehran, 14155-6455 Tehran, Iran
| | - Estefania Acaz-Fonseca
- Instituto Cajal (D.G., S.G., E.A.-F., I.R.P., L.M.G.-S.), Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain; Institute of Anatomy and Cell Biology (D.G.), Department of Molecular Embryology, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany; and Department of Cell and Molecular Biology (S.G.), School of Biology, College of Science, University of Tehran, 14155-6455 Tehran, Iran
| | - Isabel Ruiz-Palmero
- Instituto Cajal (D.G., S.G., E.A.-F., I.R.P., L.M.G.-S.), Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain; Institute of Anatomy and Cell Biology (D.G.), Department of Molecular Embryology, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany; and Department of Cell and Molecular Biology (S.G.), School of Biology, College of Science, University of Tehran, 14155-6455 Tehran, Iran
| | - Luis M Garcia-Segura
- Instituto Cajal (D.G., S.G., E.A.-F., I.R.P., L.M.G.-S.), Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain; Institute of Anatomy and Cell Biology (D.G.), Department of Molecular Embryology, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany; and Department of Cell and Molecular Biology (S.G.), School of Biology, College of Science, University of Tehran, 14155-6455 Tehran, Iran
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11
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Yamaguchi K. Evaluation for roles of neurosteroids in modulating forebrain mechanisms controlling vasopressin secretion and related phenomena in conscious rats. Neurosci Res 2015; 95:38-50. [PMID: 25598212 DOI: 10.1016/j.neures.2015.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 11/20/2014] [Accepted: 01/08/2015] [Indexed: 11/28/2022]
Abstract
Anteroventral third ventricular region (AV3V) that regulates autonomic functions through a GABAergic mechanism possesses neuroactive steroid (NS)-synthesizing ability. Although NS can exert effects by acting on a certain type of GABAA-receptor (R), it is not clear whether NS may operate to modulate AV3V GABAergic activity for controlling autonomic functions. This study aimed to investigate the issue. AV3V infusion with a GABAA antagonist bicuculline increased plasma vasopressin (AVP), glucose, blood pressure (BP), and heart rate in rats. These events were abolished by preinjecting its agonist muscimol, whereas the infusion with allopregnanolone, a NS capable of potentiating GABAA-R function, affected none of the variables in the absence or presence of such bicuculline actions. Similarly, AV3V infusion with pregnanolone sulfate, a NS capable of antagonizing GABAA-R, produced no effect on those variables. AV3V infusion with muscimol was effective in inhibiting the responses of plasma AVP or glucose, or BP to an osmotic loading or bleeding. However, AV3V infusion with aminoglutethimide, a NS synthesis inhibitor, did not affect any of the variables in the absence or presence of those stimuli. These results suggest that NS may not cause acute effects on the AV3V GABAergic mechanism involved in regulating AVP release and other autonomic function.
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Affiliation(s)
- Ken'ichi Yamaguchi
- Department of Homeostatic Regulation and Development, Niigata University Graduate School of Medical and Dental Sciences, Niigata City 951-8510, Japan.
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12
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Hill M, Dušková M, Stárka L. Dehydroepiandrosterone, its metabolites and ion channels. J Steroid Biochem Mol Biol 2015; 145:293-314. [PMID: 24846830 DOI: 10.1016/j.jsbmb.2014.05.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 05/06/2014] [Accepted: 05/11/2014] [Indexed: 11/20/2022]
Abstract
This review is focused on the physiological and pathophysiological relevance of steroids influencing the activities of the central and peripheral nervous systems with regard to their concentrations in body fluids and tissues in various stages of human life like the fetal development or pregnancy. The data summarized in this review shows that DHEA and its unconjugated and sulfated metabolites are physiologically and pathophysiologically relevant in modulating numerous ion channels and participate in vital functions of the human organism. DHEA and its unconjugated and sulfated metabolites including 5α/β-reduced androstane steroids participate in various physiological and pathophysiological processes like the management of GnRH cyclic release, regulation of glandular and neurotransmitter secretions, maintenance of glucose homeostasis on one hand and insulin insensitivity on the other hand, control of skeletal muscle and smooth muscle activities including vasoregulation, promotion of tolerance to ischemia and other neuroprotective effects. In respect of prevalence of steroid sulfates over unconjugated steroids in the periphery and the opposite situation in the CNS, the sulfated androgens and androgen metabolites reach relevance in peripheral organs. The unconjugated androgens and estrogens are relevant in periphery and so much the more in the CNS due to higher concentrations of most unconjugated steroids in the CNS tissues than in circulation and peripheral organs. This article is part of a Special Issue entitled "Essential role of DHEA".
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Affiliation(s)
- M Hill
- Steroid Hormone Unit, Institute of Endocrinology, Národní třída 8, Prague 116 94, Praha 1, CZ 116 94, Czech Republic.
| | - M Dušková
- Steroid Hormone Unit, Institute of Endocrinology, Národní třída 8, Prague 116 94, Praha 1, CZ 116 94, Czech Republic.
| | - L Stárka
- Steroid Hormone Unit, Institute of Endocrinology, Národní třída 8, Prague 116 94, Praha 1, CZ 116 94, Czech Republic.
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Song Z, Levin BE, Stevens W, Sladek CD. Supraoptic oxytocin and vasopressin neurons function as glucose and metabolic sensors. Am J Physiol Regul Integr Comp Physiol 2014; 306:R447-56. [PMID: 24477542 DOI: 10.1152/ajpregu.00520.2013] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neurons in the supraoptic nuclei (SON) produce oxytocin and vasopressin and express insulin receptors (InsR) and glucokinase. Since oxytocin is an anorexigenic agent and glucokinase and InsR are hallmarks of cells that function as glucose and/or metabolic sensors, we evaluated the effect of glucose, insulin, and their downstream effector ATP-sensitive potassium (KATP) channels on calcium signaling in SON neurons and on oxytocin and vasopressin release from explants of the rat hypothalamo-neurohypophyseal system. We also evaluated the effect of blocking glucokinase and phosphatidylinositol 3 kinase (PI3K; mediates insulin-induced mobilization of glucose transporter, GLUT4) on responses to glucose and insulin. Glucose and insulin increased intracellular calcium ([Ca(2+)]i). The responses were glucokinase and PI3K dependent, respectively. Insulin and glucose alone increased vasopressin release (P < 0.002). Oxytocin release was increased by glucose in the presence of insulin. The oxytocin (OT) and vasopressin (VP) responses to insulin+glucose were blocked by the glucokinase inhibitor alloxan (4 mM; P ≤ 0.002) and the PI3K inhibitor wortmannin (50 nM; OT: P = 0.03; VP: P ≤ 0.002). Inactivating K ATP channels with 200 nM glibenclamide increased oxytocin and vasopressin release (OT: P < 0.003; VP: P < 0.05). These results suggest that insulin activation of PI3K increases glucokinase-mediated ATP production inducing closure of K ATP channels, opening of voltage-sensitive calcium channels, and stimulation of oxytocin and vasopressin release. The findings are consistent with SON oxytocin and vasopressin neurons functioning as glucose and "metabolic" sensors to participate in appetite regulation.
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Affiliation(s)
- Zhilin Song
- Department of Physiology, University of Colorado School of Medicine, Aurora, Colorado
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14
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Differential and reproductive stage-dependent regulation of vasotocin secretion by catecholamines in the catfish Heteropneustes fossilis. Comp Biochem Physiol A Mol Integr Physiol 2013; 166:619-26. [DOI: 10.1016/j.cbpa.2013.09.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/04/2013] [Accepted: 09/05/2013] [Indexed: 12/15/2022]
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15
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Chaube R, Singh RK, Joy KP. Estrogen regulation of brain vasotocin secretion in the catfish Heteropneustes fossilis: an interaction with catecholaminergic system. Gen Comp Endocrinol 2012; 175:206-13. [PMID: 22138221 DOI: 10.1016/j.ygcen.2011.11.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 10/22/2011] [Accepted: 11/11/2011] [Indexed: 02/04/2023]
Abstract
Vasotocin (VT) is a basic neurohypophysial nonapeptide in non-mammalian vertebrates and is involved in diverse functions like osmoregulation, reproduction, metabolism and behavior. In this study, we report that estradiol-17β (E(2)) regulates brain and plasma VT secretion through the involvement of the catecholaminergic (CA) system. To demonstrate this, E(2) level was altered through ovariectomy (OVX, 3 weeks) and replacement study with low and high E(2) doses (0.1 and 0.5 μg/g body weight). CA activity was inhibited by treatment with α-methylparatyrosine (α-MPT; 250 μg/g body weight), a competitive inhibitor of tyrosine hydroxylase. VT was assayed by an enzyme immunoassay method. In the sham group, the low E(2) dose produced 82% and 104% increase, respectively, in brain and plasma VT levels. The high E(2) dose decreased the VT levels significantly. The low E(2) dose decreased brain E(2) but elevated plasma E(2). In the high E(2) group, the E(2) level increased further in both brain and plasma. OVX resulted in a significant inhibition (69% and 25%, respectively) of both brain and plasma VT, which was correlated with low E(2) levels. The low E(2) dose not only reversed the inhibition, but increased the VT level in both brain and plasma in comparison to the sham groups. The high E(2) replacement inhibited VT levels further low in both brain and plasma. The α-MPT treatment inhibited VT levels significantly in both sham and OVX groups. The drug treatment abolished partially the restorative effect of the low E(2) dose in the ovariectomized fish. In the high E(2) dose group, α-MPT decreased brain and plasma VT levels further low compared to the sham + 0. 5 μg E(2) group or OVX + 0.5 μg E(2) group except the brain VT level, which increased in the OVX+0.5 μg E(2) group. It is inferred that E(2) may exert biphasic effects on VT through the mediation of the CA system.
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Affiliation(s)
- Radha Chaube
- Zoology Section, Mahila Mahavidyalaya, Banaras Hindu University, Varanasi 221 005, India
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16
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Kodavanti PRS, Curras-Collazo MC. Neuroendocrine actions of organohalogens: thyroid hormones, arginine vasopressin, and neuroplasticity. Front Neuroendocrinol 2010; 31:479-96. [PMID: 20609372 DOI: 10.1016/j.yfrne.2010.06.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 06/22/2010] [Accepted: 06/25/2010] [Indexed: 02/08/2023]
Abstract
Organohalogen compounds are global environmental pollutants. They are highly persistent, bioaccumulative, and cause adverse effects in humans and wildlife. Because of the widespread use of these organohalogens in household items and consumer products, indoor contamination may be a significant source of human exposure, especially for children. One significant concern with regard to health effects associated with exposure to organohalogens is endocrine disruption. This review focuses on PCBs and PBDEs as old and new organohalogens, respectively, and their effects on two neuroendocrine systems; thyroid hormones and the arginine vasopressin system (AVP). Regarding neuroendocrine effects of organohalogens, there is considerable information on the thyroid system as a target and evidence is now accumulating that the AVP system and associated functions are also susceptible to disruption. AVP-mediated functions such as osmoregulation, cardiovascular function as well as social behavior, sexual function and learning/memory are discussed. For both thyroid and AVP systems, the timing of exposure seems to play a major role in the outcome of adverse effects. The mechanism of organohalogen action is well understood for the thyroid system. In comparison, this aspect is understudied in the AVP system but some similarities in neural processes, shown to be targeted by these pollutants, serve as promising possibilities for study. One challenge in understanding modes of action within neuroendocrine systems is their complexity stemming, in part, from interdependent levels of organization. Further, because of the interplay between neuroendocrine and neural functions and behavior, further investigation into organohalogen-mediated effects is warranted and may yield insights with wider scope. Indeed, the current literature provides scattered evidence regarding the role of organohalogen-induced neuroendocrine disruption in the neuroplasticity related to both learning functions and brain structure but future studies are needed to establish the role of endocrine disruption in nervous system function and development.
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Affiliation(s)
- Prasada Rao S Kodavanti
- Neurotoxicology Branch, Toxicity Assessment Division, B 105-06, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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17
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Grassi D, Amorim MA, Garcia-Segura LM, Panzica G. Estrogen receptor α is involved in the estrogenic regulation of arginine vasopressin immunoreactivity in the supraoptic and paraventricular nuclei of ovariectomized rats. Neurosci Lett 2010; 474:135-139. [DOI: 10.1016/j.neulet.2010.03.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 02/21/2010] [Accepted: 03/09/2010] [Indexed: 01/25/2023]
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18
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Przybycien-Szymanska MM, Rao YS, Pak TR. Binge-pattern alcohol exposure during puberty induces sexually dimorphic changes in genes regulating the HPA axis. Am J Physiol Endocrinol Metab 2010; 298:E320-8. [PMID: 19952347 PMCID: PMC2822472 DOI: 10.1152/ajpendo.00615.2009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Maternal alcohol consumption during critical periods of fetal brain development leads to devastating long-term consequences on adult reproductive physiology, cognitive function, and social behaviors. However, very little is known about the long-term consequences of alcohol consumption during puberty, which is perhaps an equally dynamic and critical period of brain development. Alcohol abuse during adulthood has been linked with an increase in clinically diagnosed anxiety disorders, yet the etiology and neurochemical mechanisms of alcohol-induced anxiety behavior is unknown. In this study, we determined the effects of binge ethanol exposure during puberty on two critical central regulators of stress and anxiety behavior: corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP). Our results showed that ethanol increased plasma corticosterone (CORT) levels in both sexes, yet binge-treated animals had significantly lower CORT levels than animals exposed to a single dose, suggesting that the hypothalamo-pituitary-adrenal (HPA) axis habituated to the repeated stressful stimuli of ethanol. Binge ethanol exposure also significantly increased CRH and AVP gene expression in the paraventricular nucleus of males, but not females. Overall, our results demonstrate that binge ethanol exposure during puberty changes the central expression of stress-related genes in a sex-specific manner, potentially leading to permanent dysregulation of the HPA axis and long-term behavioral consequences.
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Scott CJ, Clarke IJ, Tilbrook AJ. The effect of testosterone and season on prodynorphin messenger RNA expression in the preoptic area-hypothalamus of the ram. Domest Anim Endocrinol 2008; 34:440-50. [PMID: 18308503 DOI: 10.1016/j.domaniend.2008.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 01/08/2008] [Accepted: 01/08/2008] [Indexed: 11/27/2022]
Abstract
Testosterone and season influence mRNA expression for the opioid, enkephalin, in the preoptic area and hypothalamus of rams. Dynorphin is another opioid which has been shown to play a role in the control of reproductive function in females. We now report effects of season and testosterone on the expression of prodynorphin mRNA in the hypothalamus of the ram. Castrated adult Romney Marsh rams (5/group) received vehicle or testosterone propionate (i.m.) during either the 'breeding' season or 'non-breeding' season. Prodynorphin mRNA expression was quantified in the hypothalami by in situ hybridisation. Testosterone treatment increased prodynorphin mRNA expression in the supraoptic nucleus and the bed nucleus of the stria terminalis in the breeding season but not during the non-breeding season. Prodynorphin mRNA expression was also higher in the breeding season than in the non-breeding season in the caudal preoptic area, paraventricular nucleus and accessory supraoptic nucleus, irrespective of treatment. No effects of treatment were observed in any other regions of the hypothalamus. We conclude that testosterone and season regulate prodynorphin mRNA expression in a region-specific manner, which may influence seasonal changes in reproductive function.
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Affiliation(s)
- Christopher J Scott
- Department of Physiology, Monash University, Vic., Australia; School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia.
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20
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Estrogen receptors: their roles in regulation of vasopressin release for maintenance of fluid and electrolyte homeostasis. Front Neuroendocrinol 2008; 29:114-27. [PMID: 18022678 PMCID: PMC2274006 DOI: 10.1016/j.yfrne.2007.08.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Revised: 06/28/2007] [Accepted: 08/14/2007] [Indexed: 11/22/2022]
Abstract
Long standing interest in the impact of gonadal steroid hormones on fluid and electrolyte balance has led to a body of literature filled with conflicting reports about gender differences, the effects of gonadectomy, hormone replacement, and reproductive cycles on plasma vasopressin (VP), VP secretion, and VP gene expression. This reflects the complexity of gonadal steroid hormone actions in the body resulting from multiple sites of action that impact fluid and electrolyte balance (e.g. VP target organs, afferent pathways regulating the VP neurons, and the VP secreting neurons themselves). It also reflects involvement of multiple types of estrogen receptors (ER) in these diverse sites including ERs that act as transcription factors regulating gene expression (i.e. the classic ERalpha as well as the more recently discovered ERbeta) and potentially G-protein coupled, membrane localized ERs that mediate rapid non-genomic actions of estrogen. Furthermore, altered expression of these receptors in physiologically diverse conditions of fluid and electrolyte balance contributes to the difficulty of using simplistic approaches such as gender comparisons, gonadectomy, and hormone replacement to assess the role of gonadal steroids in regulation of VP secretion for maintenance of fluid and electrolyte homeostasis. This review catalogs these inconsistencies and provides a frame work for understanding them by describing: (1) the effect of gonadal steroids on target organ responsiveness to VP; (2) the expression of multiple types of estrogen receptors in the VP neurons and in brain regions monitoring feedback signals from the periphery; and (3) the impact of dehydration and hyponatremia on expression of these receptors.
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21
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Pirnik Z, Jezova D, Mikkelsen JD, Kiss A. Xylazine activates oxytocinergic but not vasopressinergic hypothalamic neurons under normal and hyperosmotic conditions in rats. Neurochem Int 2005; 47:458-65. [PMID: 16125277 DOI: 10.1016/j.neuint.2005.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2005] [Revised: 07/07/2005] [Accepted: 07/12/2005] [Indexed: 11/26/2022]
Abstract
Role of central alpha2-adrenoceptors in the regulation of hypothalamic magnocellular cells was studied under hyperosmotic challenge elicited by hypertonic saline (HS). Rats pretreated with receptor agonist, xylazine (XYL), were injected intraperitoneally with different (low: 0.375, moderate: 0.75, high: 1.5 M) HS 30 min later. The activity of the paraventricular (PVN) and supraoptic (SON) vasopressin and oxytocin perikarya was established by Fos-dual-immunohistochemistry 60 min after HS administration. Results showed that 1/XYL is a potent stimulus for oxytocin but not vasopressin magnocellular cells under basal and weak hyperosmotic conditions 2/highHS completely overlaps the effect of XYL. In addition, XYL partially suppressed Fos expression in the parvocellular PVN cells activated by highHS. The data suggest that alpha2-adrenoceptors may play an important role in the regulation of oxytocinergic PVN and SON neurons under basal and weak hyperosmotic conditions and that alpha2-adrenoceptors may also participate in the control of PVN parvocellular cells under intense osmotic challenge.
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Affiliation(s)
- Z Pirnik
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska str. 3, 833 06 Bratislava, Slovakia
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22
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Lipschitz DL, Crowley WR, Armstrong WE, Bealer SL. Neurochemical bases of plasticity in the magnocellular oxytocin system during gestation. Exp Neurol 2005; 196:210-23. [PMID: 16157332 DOI: 10.1016/j.expneurol.2005.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Revised: 07/14/2005] [Accepted: 08/06/2005] [Indexed: 11/22/2022]
Abstract
The central and systemic release of oxytocin (OT) has been well documented during parturition and lactation. In preparation for the demands of these events, the magnocellular hypothalamic neurons of the central OT system undergo a variety of biochemical, molecular, electrophysiological, and anatomical adaptations during gestation. However, the mechanisms responsible for these changes have not been well established. A number of neurochemical mediators have been implicated in contributing to the plasticity in the OT magnocellular system during gestation, including ovarian hormones, as well as central neurotransmitters, such as glutamate, gamma-amino butyric acid (GABA), and central neurosteroids, e.g., allopregnanolone. In addition, several lines of evidence suggest that central OT release and subsequent OT receptor stimulation may contribute to adaptations of the OT system during gestation, and may be necessary for its subsequent functioning during lactation. Here, we review evidence for involvement of the neurochemical systems implicated in contributing to adaptations that occur in the OT system during the course of gestation.
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Affiliation(s)
- D L Lipschitz
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, 30 South 2000 East, Rm 201, Salt Lake City, UT 84112, USA
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23
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Di S, Malcher-Lopes R, Marcheselli VL, Bazan NG, Tasker JG. Rapid glucocorticoid-mediated endocannabinoid release and opposing regulation of glutamate and gamma-aminobutyric acid inputs to hypothalamic magnocellular neurons. Endocrinology 2005; 146:4292-301. [PMID: 15994343 DOI: 10.1210/en.2005-0610] [Citation(s) in RCA: 217] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Glucocorticoids secreted in response to stress activation of the hypothalamic-pituitary-adrenal axis feed back onto the brain to rapidly suppress neuroendocrine activation, including oxytocin and vasopressin secretion. Here we show using whole-cell patch clamp recordings that glucocorticoids elicit a rapid, opposing action on synaptic glutamate and gamma-aminobutyric acid (GABA) release onto magnocellular neurons of the hypothalamic supraoptic nucleus and paraventricular nucleus, suppressing glutamate release and facilitating GABA release by activating a putative membrane receptor. The glucocorticoid effect on both glutamate and GABA release was blocked by inhibiting postsynaptic G protein activity, suggesting a dependence on postsynaptic G protein signaling and the involvement of a retrograde messenger. Biochemical analysis of hypothalamic slices treated with dexamethasone revealed a glucocorticoid-induced rapid increase in the levels of the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG). The glucocorticoid suppression of glutamate release was blocked by the type I cannabinoid receptor cannabinoid receptor antagonist, AM251, and was mimicked and occluded by AEA and 2-AG, suggesting it was mediated by retrograde endocannabinoid release. The glucocorticoid facilitation of GABA release was also blocked by AM251 but was not mimicked by AEA, 2-AG, or a synthetic cannabinoid, WIN 55,212-2, nor was it blocked by vanilloid or ionotropic glutamate receptor antagonists, suggesting that it was mediated by a retrograde messenger acting at an AM251-sensitive, noncannabinoid/nonvanilloid receptor at presynaptic GABA terminals. The combined, opposing actions of glucocorticoids mediate a rapid inhibition of the magnocellular neuroendocrine cells, which in turn should mediate rapid feedback inhibition of the secretion of oxytocin and vasopressin by glucocorticoids during stress activation of the hypothalamic-pituitary-adrenal axis.
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Affiliation(s)
- Shi Di
- Division of Neurobiology, Tulane University, New Orleans, Louisiana 70118-5698, USA
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24
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Forsling ML, Kalló I, Hartley DE, Heinze L, Ladek R, Coen CW, File SE. Oestrogen receptor-beta and neurohypophysial hormones: functional interaction and neuroanatomical localisation. Pharmacol Biochem Behav 2003; 76:535-42. [PMID: 14643853 DOI: 10.1016/j.pbb.2003.09.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Oestrogens affect fluid balance, influencing both ingestive behaviour and renal excretion. The renal effects are partly due to altered release of vasopressin and oxytocin. This study was designed to explore the role of oestrogen receptor-beta (ERbeta) in neurohypophysial hormonal function. Following dietary administration, soya isoflavones reach the brain in sufficient concentration to activate ERbeta, but not oestrogen receptor-alpha (ERalpha). ERbeta function was therefore manipulated by feeding rat diets differing in soya isoflavone content. Fluid balance and neurohypophysial hormone release were measured in male rats maintained for 14 days on a soya isoflavone-free diet or one containing 150 microg/g genistein+daidzein. Food and water intake, body weight, urine flow, osmolality and sodium concentrations were determined daily. After 14 days, plasma and urine osmolality and sodium, vasopressin and oxytocin concentrations were determined. There was no significant difference in weight gain between the two groups or in their excretion of sodium and water or plasma sodium and plasma oxytocin. However, plasma vasopressin was significantly lower in the iso-free group. Double-label immunocytochemistry was used to assess colocalisation of ERbeta with the neurohypophysial hormones in male rats. Cell nuclei showing ERbeta immunoreactivity were abundant in the posterior magnocellular paraventricular nucleus (PVNpm) and in the supraoptic nucleus (SON). Vasopressin-immunoreactive neurones were similarly distributed, forming the core of the PVNpm and the ventral portion of the SON; majority were positive for ERbeta. Cells with oxytocin immunoreactivity were located mainly at the periphery of the PVNpm and in the dorsal SON; only approximately a quarter of these cells showed ERbeta immunoreactivity. Thus, the difference in the effects of the soya diet on vasopressin and oxytocin release may be related to the ERbeta-activating properties of this diet and to the preponderance of this receptor in vasopressin as opposed to oxytocin cells.
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Affiliation(s)
- M L Forsling
- Neuroendocrine and Psychopharmacology Research Laboratories, Centre for Neuroscience, King's College London, Guy's Campus, London SE1 1UL, UK.
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25
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Engelmann M, Wolf G, Horn TFW. Release patterns of excitatory and inhibitory amino acids within the hypothalamic supraoptic nucleus in response to direct nitric oxide administration during forced swimming in rats. Neurosci Lett 2002; 324:252-4. [PMID: 12009534 DOI: 10.1016/s0304-3940(02)00211-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The effect of direct intrahypothalamic nitric oxide (NO) administration on the release of selected amino acids in the hypothalamic supraoptic nucleus (SON) with and without concomitant forced swimming was investigated. Adult male Wistar rats were chronically fitted with U-shaped microdialysis probes in the SON and forced to swim for 10-min in 20-degree C warm water. Thirty-min microdialysis samples were collected before, during and after the forced swimming period while NO was administered into the SON via microdialysis. The results show that NO administration in combination with forced swimming affects the release of aspartate, glutamate, taurine, and gamma aminobutyric acid (GABA) in different patterns. Whereas the release of the excitatory amino acids aspartate and glutamate was triggered only during NO administration and forced swimming, the inhibitory amino acids GABA and taurine were found in the extracellular fluid in increased concentrations also after the treatment. These data indicate that NO administration differently affects the release of excitatory and inhibitory amino acids within the SON. Thus, SON neurons which contain high concentrations of neuronal NO synthase, might contribute to the regulation of their own secretory activity by releasing NO that controls the orchestrated release of excitatory and inhibitory amino acids from axon terminals of afferences and interneurons as well as release from glial cells.
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Affiliation(s)
- Mario Engelmann
- Otto-von-Guericke-Universität Magdeburg, Institut für Medizinische Neurobiologie, Leipziger Str. 44, D-39120 Magdeburg, Germany.
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26
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Liu CY, Chen LB, Liu PY, Xie DP, Wang PS. Effects of progesterone on gastric emptying and intestinal transit in male rats. World J Gastroenterol 2002; 8:338-41. [PMID: 11925620 PMCID: PMC4658379 DOI: 10.3748/wjg.v8.i2.338] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the dose-dependent of progesterone (P) effect and the interaction between the oxytocin (OT) and P on gastrointestinal motility.
METHODS: In order to monitor the gastric emptying and intestinal transit, the SD male rats were intubated via a catheter with normal saline (3 mL/kg) containing Na251CrO4 (0.5 μCi/mL) and 10% charcoal. OT was dissolved into normal saline and P was dissolved into 75% alcohol.
RESULTS: Low does of P (1 mg/kg, i.p.) enhanced the gastric emptying (75% ± 3%, P < 0.05) and high dose of P (5 mg/kg, i.p.) inhibit it (42% ± 11.2%, P < 0.01). P (1 mg/kg) increased the intestinal transit (4.2 ± 0.3, P < 0.05) while the higher dose (10-20 mg/kg) had no effect. OT (0.8 mg/kg, i.p.) inhibited the gastric emptying (23.5% ± 9.8%, P < 0.01). The inhibitory effects of P (20 mg/kg) (32% ± 9.7%, P < 0.05) and OT (0.8 mg/kg) on gastric emptying enhanced each other when the two chemicals were administrated simultaneously (17% ± 9.4%, P < 0.01).
CONCLUSION: Low dose of P increased GI motility while high dose of P decreased it. During the later period of pregnancy, elevated plasma level of OT may also participate in the gastrointestinal inhibition.
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Affiliation(s)
- Chuan-Yong Liu
- Department of Physiology, School of Medicine, Shandong University, Jinan 250012, Shandong Province, China.
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Morsette DJ, Sidorowicz H, Sladek CD. Role of non-NMDA receptors in vasopressin and oxytocin release from rat hypothalamo-neurohypophysial explants. Am J Physiol Regul Integr Comp Physiol 2001; 280:R313-22. [PMID: 11208557 DOI: 10.1152/ajpregu.2001.280.2.r313] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glutamate is recognized as a prominent excitatory transmitter in the supraoptic nucleus (SON) and is involved in transmission of osmoregulatory information from the osmoreceptors to the vasopressin (VP) and oxytocin (OT) neurons. Explants of the hypothalamo-neurohypophysial system were utilized to characterize the roles of the non-N-methyl-D-aspartate (NMDA) glutamate receptor subtypes (non-NMDA-Rs), kainic acid receptors (KA-Rs), and aminopropionic acid receptors (AMPA-Rs) and to evaluate the interdependence of NMDA-Rs and non-NMDA-Rs in eliciting hormone release. Although both KA and AMPA increased hormone release, a specific agonist of the KA-Rs, SYM-2081, was not effective. This combined with the finding that cyclothiazide, an agent that inhibits the desensitization of AMPA-Rs, increased the VP response to both KA and AMPA indicates that the increase in hormone release induced by the non-NMDA agonists is mediated via AMPA-Rs, rather than KA-Rs. Inhibition of osmotically stimulated VP and OT release by a specific AMPA-R antagonist indicated that AMPA-Rs are essential for mediating osmotically stimulated hormone release. NMDA-stimulated VP but not OT release was prevented by blockade of non-NMDA-Rs, but AMPA-stimulated VP/OT release was not prevented by NMDA-R blockade.
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Affiliation(s)
- D J Morsette
- Department of Physiology and Biophysics, Finch University of Health Sciences, The Chicago Medical School, North Chicago, Illinois 60064, USA
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