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Cho SY, Roh HT. Effects of Exercise Training on Neurotrophic Factors and Blood-Brain Barrier Permeability in Young-Old and Old-Old Women. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:16896. [PMID: 36554777 PMCID: PMC9778715 DOI: 10.3390/ijerph192416896] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/11/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Aging and regular exercise may have opposite effects on brain health, and although oxidative stress and sirtuins may be involved in these effects, studies on this topic are limited. Accordingly, the present study aimed to verify the effect of exercise training on oxidant-antioxidant balance, neurotrophic factors, blood-brain barrier permeability, and sirtuins in young-old and old-old women. The study participants were 12 women aged 65-74 years (Young-Old group) and 12 women aged 75-84 years (Old-Old group). All of the selected participants performed exercise training consisting of treadmill walking and resistance band exercise three times a week for 12 weeks. Blood samples were collected before and after exercise training to analyze serum oxidant-antioxidant markers (reactive oxygen species [ROS], superoxide dismutase [SOD]), neurotrophic factor (brain-derived neurotrophic factor [BDNF], vascular endothelial growth factor [VEGF]) levels, and blood-brain barrier permeability marker (S100 calcium-binding protein β [S100β], matrix metalloproteinase-9 [MMP-9]) levels, and sirtuin (SIRT-1, SIRT-2, SIRT-3) levels. The Young-Old group showed significantly increased SOD, BDNF, VEGF, SIRT-1, and SIRT-3 levels after training in comparison with the levels before training (p < 0.05), and a significantly higher BDNF level than the Old-Old group after training (p < 0.05). On the other hand, the Old-Old group showed significantly higher SIRT-1 levels after training in comparison with the levels before training (p < 0.05). Thus, exercise training may be effective in increasing the levels of neurotropic factors and reducing blood-brain barrier permeability in the elderly women, and increased antioxidant capacity and elevated levels of sirtuins are believed to play a major role in these effects. The positive effect of exercise may be greater in participants of relatively young age.
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Affiliation(s)
- Su-Youn Cho
- Exercise Physiology Laboratory, Department of Physical Education, Yonsei University, Seoul 03722, Republic of Korea
| | - Hee-Tae Roh
- Department of Sports Science, College of Health Science, Sun Moon University, 70 Sunmoon-ro 221 beon-gil, Tangjeong-myeon, Asan-si 31460, Republic of Korea
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Atila C, Monnerat S, Urwyler SA, Refardt J, Winzeler B, Christ-Crain M. The effect of glucose dynamics on plasma copeptin levels upon glucagon, arginine, and macimorelin stimulation in healthy adults : Data from: Glucacop, Macicop, and CARGO study. Pituitary 2022; 25:636-644. [PMID: 35723775 PMCID: PMC9345811 DOI: 10.1007/s11102-022-01240-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/06/2022] [Indexed: 11/17/2022]
Abstract
PURPOSE Non-osmotic stimulation tests using glucagon, arginine, or macimorelin were recently evaluated for their ability to assess posterior pituitary function. Glucagon and arginine, but not macimorelin, stimulated copeptin secretion (a surrogate marker of vasopressin) and, therefore, provide novel tests to assess the posterior pituitary. The exact underlying mechanism behind their stimulatory effect remains elusive. METHODS This analysis combined data from three diagnostic studies conducted at the University Hospital Basel, Switzerland. In total, 80 healthy adults underwent the glucagon (n = 22), arginine (n = 30), or macimorelin (n = 28) stimulation tests. The primary objective was to investigate glucose course upon glucagon, arginine, and macimorelin stimulation tests and its effect on plasma copeptin release. RESULTS Upon glucagon stimulation, the median [IQR] glucose level at baseline was 5.0 [4.6, 5.2] mmol/l, peaked at 8.1 [7.2, 9.4] mmol/l after 30 min and decreased to a minimum of 3.8 [3.5, 4.5] mmol/l after 120 min. The median copeptin increase upon glucagon stimulation was 7.7 [2.6, 28.0] pmol/l. Upon arginine, the glucose level at baseline was 4.9 [4.8, 5.5] mmol/l, peaked at 6.0 [5.2, 6.4] mmol/l after 30 min and decreased to a minimum of 4.3 [3.8, 4.8] mmol/l after 60 min. The median copeptin increase upon arginine stimulation was 4.5 [2.9, 7.5] pmol/l. Upon macimorelin, glucose levels showed no notable dynamics over the 120 min, and no major change in copeptin was observed. In the pooled dataset, a decrease in glucose levels was significantly correlated with copeptin increase (ρ = 0.53, p < 0.01). CONCLUSION A similar course in plasma glucose was observed in the copeptin-stimulating test, i.e., after glucagon and arginine, while macimorelin had no effect on glucose and copeptin levels. We hypothesize that a drop in glucose levels observed upon glucagon and arginine might stimulate copeptin.
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Affiliation(s)
- Cihan Atila
- Departments of Endocrinology, Diabetology and Metabolism, University Hospital Basel, Petersgraben 4, 4031, Basel, Switzerland
- Department of Clinical Research, University of Basel, Basel, Switzerland
| | - Sophie Monnerat
- Departments of Endocrinology, Diabetology and Metabolism, University Hospital Basel, Petersgraben 4, 4031, Basel, Switzerland
- Department of Clinical Research, University of Basel, Basel, Switzerland
| | - Sandrine Andrea Urwyler
- Departments of Endocrinology, Diabetology and Metabolism, University Hospital Basel, Petersgraben 4, 4031, Basel, Switzerland
- Department of Clinical Research, University of Basel, Basel, Switzerland
| | - Julie Refardt
- Departments of Endocrinology, Diabetology and Metabolism, University Hospital Basel, Petersgraben 4, 4031, Basel, Switzerland
- Department of Clinical Research, University of Basel, Basel, Switzerland
| | - Bettina Winzeler
- Departments of Endocrinology, Diabetology and Metabolism, University Hospital Basel, Petersgraben 4, 4031, Basel, Switzerland
- Department of Clinical Research, University of Basel, Basel, Switzerland
| | - Mirjam Christ-Crain
- Departments of Endocrinology, Diabetology and Metabolism, University Hospital Basel, Petersgraben 4, 4031, Basel, Switzerland.
- Department of Clinical Research, University of Basel, Basel, Switzerland.
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Coletti R, de Lima JBM, Vechiato FMV, de Oliveira FL, Debarba LK, Almeida-Pereira G, Elias LLK, Antunes-Rodrigues J. Nitric oxide acutely modulates hypothalamic and neurohypophyseal carbon monoxide and hydrogen sulphide production to control vasopressin, oxytocin and atrial natriuretic peptide release in rats. J Neuroendocrinol 2019; 31:e12686. [PMID: 30633838 DOI: 10.1111/jne.12686] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 01/07/2019] [Accepted: 01/07/2019] [Indexed: 12/11/2022]
Abstract
Nitric oxide (NO) negatively modulates the secretion of vasopressin (AVP), oxytocin (OT) and atrial natriuretic peptide (ANP) induced by the increase in extracellular osmolality, whereas carbon monoxide (CO) and hydrogen sulphide (H2 S) act to potentiate it; however, little information is available for the osmotic challenge model about whether and how such gaseous systems modulate each other. Therefore, using an acute ex vivo model of hypothalamic and neurohypophyseal explants (obtained from male 6/7-week-old Wistar rats) under conditions of extracellular iso- and hypertonicity, we determined the effects of NO (600 μmol L-1 sodium nitroprusside), CO (100 μmol L-1 tricarbonylchloro[glycinato]ruthenium [II]) and H2 S (10 mmol L-1 sodium sulphide) donors and nitric oxide synthase (NOS) (300 μmol L-1 Nω -methyl-l-arginine [LNMMA]), haeme oxygenase (HO) (200 μmol L-1 Zn(II) deuteroporphyrin IX 2,4-bis-ethylene glycol [ZnDPBG]) and cystathionine β-synthase (CBS) (100 μmol L-1 aminooxyacetate [AOA]) inhibitors on the release of hypothalamic ANP and hypothalamic and neurohypophyseal AVP and OT, as well as on the activities of NOS, HO and CBS. LNMMA reversed hyperosmolality-induced NOS activity, and enhanced hormonal release by the hypothalamus and neurohypophysis, in addition to increasing CBS and hypothalamic HO activity. AOA decreased hypothalamic and neurohypophyseal CBS activity and hormonal release, whereas ZnDPBG inhibited HO activity and hypothalamic hormone release; however, in both cases, AOA did not modulate NOS and HO activity and ZnDPBG did not affect NOS and CBS activity. Thus, our data indicate that, although endogenous CO and H2 S positively modulate AVP, OT and ANP release, only NO plays a concomitant role of modulator of hormonal release and CBS activity in the hypothalamus and neurohypophysis and that of HO activity in the hypothalamus during an acute osmotic stimulus, which suggests that NO is a key gaseous controller of the neuroendocrine system.
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Affiliation(s)
- Ricardo Coletti
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | | | | | | | - Lucas Kniess Debarba
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Gislaine Almeida-Pereira
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | | | - José Antunes-Rodrigues
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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Javadian N, Rahimi N, Javadi-Paydar M, Doustimotlagh AH, Dehpour AR. The modulatory effect of nitric oxide in pro- and anti-convulsive effects of vasopressin in PTZ-induced seizures threshold in mice. Epilepsy Res 2016; 126:134-40. [PMID: 27497813 DOI: 10.1016/j.eplepsyres.2016.07.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 07/09/2016] [Accepted: 07/25/2016] [Indexed: 11/25/2022]
Abstract
Vasopressin neuropeptides play an important role in the several cognitive, social, and neuroendocrine functions. Also, several studies report the involvement of nitrergic system in the vasopressin functions in central nervous system. This study investigates the effect of Arginine-Vasopressin (AVP) in pentylenetetrazol (PTZ)-induced seizures threshold and the probable role of nitric oxide (NO). AVP is administered intraperitoneally (0.01-20μg/kg, i.p.) 30min before induction of seizures. Administration of AVP (0.1μg/kg) significantly lowered the PTZ-induced seizures threshold. But, administration of AVP (10 and 20μg/kg) increased the seizures threshold, significantly. Pretreatment of SR 49059 (V1a receptor antagonist, 2mg/kg, i.p.) just reversed the pro-convulsant effect of AVP. Meanwhile, SSR 149415 (V1b receptor antagonist, 10mg/kg, i.p.) pretreatment reversed both pro-and anti-convulsant effects of AVP. The nitric oxide precursor, L-arginine (60mg/kg, i.p.) increased pro-convulsant effect of AVP, but did not change anticonvulsant activity. The nitric oxide synthase (NOS) inhibitor L-NAME (10mg/kg, i.p.) reversed both pro- and anti-convulsant effect of AVP. Selective inducible NOS inhibitor, aminoguanidine (100mg/kg, i.p.) just reversed the anti-convulsant effects of AVP. The results of the present study showed nitric oxide system may contribute to the biphasic effects of AVP on PTZ-induced seizures. V1a receptor may modulate only the proconvulsive effect. While, V1b receptors can mediate both the pro- and anti-convulsive effect of AVP.
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Affiliation(s)
- Nina Javadian
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Nastaran Rahimi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehrak Javadi-Paydar
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Amir Hossein Doustimotlagh
- Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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Reis WL, Biancardi VC, Son S, Antunes-Rodrigues J, Stern JE. Carbon monoxide and nitric oxide interactions in magnocellular neurosecretory neurones during water deprivation. J Neuroendocrinol 2015; 27:111-22. [PMID: 25494574 DOI: 10.1111/jne.12245] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 11/13/2014] [Accepted: 12/07/2014] [Indexed: 12/21/2022]
Abstract
Nitric oxide (NO) and carbon monoxide (CO) are diffusible gas messengers in the brain. Previously, we have shown their independent involvement in central fluid/electrolyte homeostasis control. In the present study, we investigated a possible functional interaction between NO/CO in the regulation of vasopressin (VP) and oxytocin (OT) magnocellular neurosecretory cells (MNCs) activity in euhydrated (EU) and dehydrated [48-h water-deprived (48WD)] rats. Using brain slices from EU and 48WD rats, we measured, by immunohistochemistry, the expression of neuronal NO synthase (nNOS, which synthesises NO) and haeme-oxygenase (HO-1, which synthesises CO) in the hypothalamic supraoptic nucleus (SON). In addition, we used patch-clamp electrophysiology to investigate whether regulation of SON MNC firing activity by endogenous CO was dependent on NO bioavailability and GABAergic inhibitory synaptic function. We found a proportion of OT and VP SON MNCs in EU rats to co-express both of HO-1 and nNOS (33.2 ± 2.9% and 15.3 ± 1.4%, respectively), which was increased in 48WD rats (55.5 ± 0.9% and 21.0 ± 1.7%, respectively, P < 0.05 for both). Inhibition of endogenous HO activity [chromium mesoporphyrin IX chloride (CrMP) 20 μm] induced MNC membrane hyperpolarisation and decreased firing activity, and these effects were blunted by previous blockade of endogenous NOS activity (l-NAME, 2 mm) or blockade of inhibitory GABA function [Picrotoxin (Sigma-Aldrich, St Louis, MO, USA), 50 μm]. No significant changes in SON NO bioavailability (4,5 diaminofluorescein diacetate fluorescence) were observed after CrMP treatment. Taken together, our results support a state-dependent functional inter-relationship between NO and CO in MNCs, in which CO acts as an excitatory gas molecule, whose effects are largely dependent on interactions with the inhibitory SON signals NO and GABA.
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Affiliation(s)
- W L Reis
- Department of Physiology, Georgia Regents University, Augusta, GA, USA; Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, Brazil
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6
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Silva MPD, Cedraz-Mercez PL, Varanda WA. Effects of nitric oxide on magnocellular neurons of the supraoptic nucleus involve multiple mechanisms. Braz J Med Biol Res 2014; 47:90-100. [PMID: 24519124 PMCID: PMC4051181 DOI: 10.1590/1414-431x20133326] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 10/22/2013] [Indexed: 01/24/2023] Open
Abstract
Physiological evidence indicates that the supraoptic nucleus (SON) is an
important region for integrating information related to homeostasis of body
fluids. Located bilaterally to the optic chiasm, this nucleus is composed of
magnocellular neurosecretory cells (MNCs) responsible for the synthesis and
release of vasopressin and oxytocin to the neurohypophysis. At the cellular
level, the control of vasopressin and oxytocin release is directly linked to the
firing frequency of MNCs. In general, we can say that the excitability of these
cells can be controlled via two distinct mechanisms: 1) the intrinsic membrane
properties of the MNCs themselves and 2) synaptic input from circumventricular
organs that contain osmosensitive neurons. It has also been demonstrated that
MNCs are sensitive to osmotic stimuli in the physiological range. Therefore, the
study of their intrinsic membrane properties became imperative to explain the
osmosensitivity of MNCs. In addition to this, the discovery that several
neurotransmitters and neuropeptides can modulate their electrical activity
greatly increased our knowledge about the role played by the MNCs in fluid
homeostasis. In particular, nitric oxide (NO) may be an important player in
fluid balance homeostasis, because it has been demonstrated that the enzyme
responsible for its production has an increased activity following a hypertonic
stimulation of the system. At the cellular level, NO has been shown to change
the electrical excitability of MNCs. Therefore, in this review, we focus on some
important points concerning nitrergic modulation of the neuroendocrine system,
particularly the effects of NO on the SON.
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Affiliation(s)
- M P da Silva
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão PretoSP, Brasil, Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - P L Cedraz-Mercez
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão PretoSP, Brasil, Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - W A Varanda
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão PretoSP, Brasil, Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
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Alterations in nitric oxide synthase in the aged CNS. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:718976. [PMID: 22829960 PMCID: PMC3399597 DOI: 10.1155/2012/718976] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/03/2012] [Accepted: 06/05/2012] [Indexed: 01/27/2023]
Abstract
Aging is associated with neuronal loss, gross weight reduction of the brain, and glial proliferation in the cortex, all of which lead to functional changes in the brain. It is known that oxidative stress is a critical factor in the pathogenesis of aging; additionally, growing evidence suggests that excessive nitric oxide (NO) production contributes to the aging process. However, it is still unclear how NO plays a role in the aging process. This paper describes age-related changes in the activity of NADPH-diaphorase (NADPH-d), a marker for neurons containing nitric oxide synthase (NOS), in many CNS regions. Understanding these changes may provide a novel perspective in identifying the aging mechanism.
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Reis WL, Biancardi VC, Son S, Antunes-Rodrigues J, Stern JE. Enhanced expression of heme oxygenase-1 and carbon monoxide excitatory effects in oxytocin and vasopressin neurones during water deprivation. J Neuroendocrinol 2012; 24:653-63. [PMID: 22060896 PMCID: PMC3314108 DOI: 10.1111/j.1365-2826.2011.02249.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A growing body of evidence indiates that carbon monoxide (CO) acts as a gas neurotransmitter within the central nervous system. Although CO has been shown to affect neurohypophyseal hormone release in response to osmotic stimuli, the precise sources, targets and mechanisms underlying the actions of CO within the magnocellular neurosecretory system remain largely unknown. In the present study, we combined immunohistochemistry and patch-clamp electrophysiology to study the cellular distribution of the CO-synthase enzyme heme oxygenase type 1 (HO-1), as well as the actions of CO on oxytocin (OT) and vasopressin (VP) magnocellular neurosecretory cells (MNCs), in euhydrated (EU) and 48-h water-deprived rats (48WD). Our results show the expression of HO-1 immunoreactivity both in OT and VP neurones, as well as in a small proportion of astrocytes, both in supraoptic (SON) and paraventricular (PVN) nuclei. HO-1 expression, and its colocalisation with OT and VP neurones within the SON and PVN, was significantly enhanced in 48WD rats. Inhibition of HO activity with chromium mesoporphyrin IX chloride (CrMP; 20 μm) resulted in a slight membrane hyperpolarisation in SON neurones from EU rats, without significantly affecting their firing activity. In 48WD rats, on the other hand, CrMP resulted in a more robust membrane hyperpolarisation, significantly decreasing neuronal firing discharge. Taken together, our results indicate that magnocellular SON and PVN neurones express HO-1, and that CO acts as an excitatory gas neurotransmitter in this system. Moreover, we found that the expression and actions of CO were enhanced in water-deprived rats, suggesting that the state-dependent up-regulation of the HO-1/CO signalling pathway contributes to enhance MNCs firing activity during an osmotic challenge.
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Affiliation(s)
- W L Reis
- Department of Physiology, Georgia Health Sciences University, Augusta, GA 30912, USA
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Aguila FA, Oliveira-Pelegrin GR, Yao ST, Murphy D, Rocha MJA. Anteroventral third ventricle (AV3V) lesion affects hypothalamic neuronal nitric oxide synthase (nNOS) expression following water deprivation. Brain Res Bull 2011; 86:239-45. [PMID: 21840380 DOI: 10.1016/j.brainresbull.2011.07.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 07/21/2011] [Accepted: 07/27/2011] [Indexed: 10/17/2022]
Abstract
Neuronal nitric oxide synthase (nNOS) has been reported to be up-regulated in the hypothalamic supraoptic nucleus (SON) during dehydration which in turn could increase nitric oxide (NO) production and consequently affect arginine vasopressin (AVP) secretion. The anteroventral third ventricle (AV3V) region has strong afferent connections with the SON. Herein we describe our analysis of the effects of an AV3V lesion on AVP secretion, and c-fos and nNOS expression in the SON following dehydration. Male Wistar rats had their AV3V region electrolytically lesioned or were sham operated. After 21 days they were submitted to dehydration or left as controls (euhydrated). Two days later, one group was anaesthetized, perfused and the brains were processed for Fos protein and nNOS immunohistochemistry (IHC). Another group was decapitated, the blood collected for hematocrit, osmolality, serum sodium and AVP plasma level analysis. The brains were removed for measurement of neurohypophyseal AVP content, and the SON was punched out and processed for nNOS detection by western blotting. The AV3V lesion reduced AVP plasma levels and c-fos expression in the SON following dehydration (P<0.05). Western blotting revealed an up-regulation of nNOS in the SON of control animals following dehydration, whereas such up-regulation was not observed in AV3V-lesioned rats (P<0.05). We conclude that the AV3V region plays a role in regulating the expression of nNOS in the SON of rats submitted to dehydration, and thus may affect the local nitric oxide production and the secretion of vasopressin.
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Affiliation(s)
- Fábio Alves Aguila
- Departamento de Morfologia, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
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Monasterio N, Morales T. Nitric oxide has a role in attenuating the neuroendocrine response to anaphylactoid stress during lactation. Brain Res 2011; 1402:54-66. [PMID: 21696708 DOI: 10.1016/j.brainres.2011.05.062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 05/20/2011] [Accepted: 05/27/2011] [Indexed: 02/05/2023]
Abstract
Stress increases nitric oxide (NO) production in the paraventricular nucleus of the hypothalamus (PVH). Lactation diminishes the response to stress and increases basal NO production markers in the PVH of the dam. This study investigated whether lactation modified the anaphylactic reaction to egg white (EW) injection, and if nitric oxide regulates the neuroendocrine response to this stressor. The activational response of PVH to EW was assessed by c-Fos immunohistochemistry, and NO production was determined by histological staining of NADPH-diaphorase and neuronal nitric oxide synthase (nNOS) and by measuring the concentration of total nitrates and nitrites (NOx) in the hypothalamus of lactating and diestrus rats. EW injection significantly increased the number of Fos-positive neurons in the parvocellular subdivision of the PVH in diestrus, but not in lactating rats. Similarly, EW injection increased the number of NADPH-diaphorase- and nNOS-positive cells in the PVH of diestrus rats, but it did not alter the already increased basal number of NO-positive cells in lactating rats. Furthermore, the total concentration of NOx in the hypothalamus, the circulating level of corticosterone and interleukin-6 increased significantly after EW in diestrus, but not in lactating rats, compared to their corresponding controls. Intracerebral administration of L-NAME, a general NOS inhibitor, reversed the attenuation of the activational response to EW in the PVH of lactating rats. The present results show that lactation diminishes the anaphylactoid reaction to EW compared to that in diestrus rats. This attenuation was absent after L-NAME treatment, suggesting that sustained NO production in the PVH during lactation may limit the neuroendocrine response to stress.
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Affiliation(s)
- Nela Monasterio
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, 76230 Querétaro, Mexico
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Oliveira-Pelegrin GR, Aguila FA, Basso PJ, Rocha MJA. Role of central NO-cGMP pathway in vasopressin and oxytocin gene expression during sepsis. Peptides 2010; 31:1847-52. [PMID: 20621145 DOI: 10.1016/j.peptides.2010.06.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 06/26/2010] [Accepted: 06/28/2010] [Indexed: 11/17/2022]
Abstract
Sepsis induces massive production of inflammatory mediators, such as nitric oxide (NO), and causes neuroendocrine and cardiovascular alterations. This study investigates the involvement of the central NO-cGMP pathway in arginine vasopressin (AVP) and oxytocin (OXY) gene expression during sepsis induced by cecal ligation and puncture (CLP). Male Wistar rats received an i.c.v. injection of ODQ (0.25 μg/μL), a selective inhibitor of the heme site of soluble guanylate cyclase, or of 1% dymethilsulfoxide (DMSO), as vehicle. Thirty minutes after the injections, sepsis was induced by cecal ligation and puncture or the animals were sham operated. The ODQ pre-treatment did not alter the progressive NO increase observed after CLP. In the supraoptic nucleus (SON), this pretreatment increased the relative gene expression ratio of AVP and OXY in the initial phase of sepsis, but in the late phase, the gene expression of both hormones was reduced. In the paraventricular nucleus (PVN), soluble guanylate cyclase inhibition caused an even larger decrease in the relative gene expression ratio of AVP and OXY during sepsis. These results are indicative of a role of the NO-cGMP pathway in hormonal synthesis in the SON and PVN of the hypothalamus during polymicrobial sepsis.
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Affiliation(s)
- Gabriela Ravanelli Oliveira-Pelegrin
- Departamento de Morfologia, Estomatologia e Fisiologia, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
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12
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Mancuso C, Navarra P, Preziosi P. Roles of nitric oxide, carbon monoxide, and hydrogen sulfide in the regulation of the hypothalamic-pituitary-adrenal axis. J Neurochem 2010; 113:563-75. [PMID: 20089135 DOI: 10.1111/j.1471-4159.2010.06606.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The importance of stress in modifying human behavior and lifestyle is no longer a matter of debate. Although mild stress enhances the immune response and prevents infections, prolonged stress seems to play pathogenic roles in depression and neurodegenerative disorders. The body has developed an adaptive stress response consisting of cardiovascular, metabolic, and psychological changes, which act in concert to eliminate stressors. One of the major components of this response is the hypothalamic-pituitary-adrenal axis, also known as the stress axis. Over the last 30 years, many studies have documented the integrated stress-axis regulation by neurotransmitters. They have also demonstrated that gaseous neuromodulators, such as NO, CO, and H(2)S, regulate the hypothalamic release of neuropeptides. The specific effects (stimulatory vs. inhibitory) of these gases on the stress axis varies, depending on the type of stress (neurogenic or immuno-inflammatory), its intensity (low or high), and the species studied (rodents or humans). This review examines the complex roles of NO, CO, and H(2)S in modulation of stress-axis activity, with particular emphasis on the regulatory effects they exert at the hypothalamic level.
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Affiliation(s)
- Cesare Mancuso
- Institute of Pharmacology, Catholic University School of Medicine, Rome, Italy.
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13
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Endothelin-1 as a neuropeptide: neurotransmitter or neurovascular effects? J Cell Commun Signal 2009; 4:51-62. [PMID: 19847673 PMCID: PMC2821480 DOI: 10.1007/s12079-009-0073-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Accepted: 09/22/2009] [Indexed: 11/25/2022] Open
Abstract
Endothelin-1 (ET-1) is an endothelium-derived peptide that also possesses potent mitogenic activity. There is also a suggestion the ET-1 is a neuropeptide, based mainly on its histological identification in both the central and peripheral nervous system in a number of species, including man. A neuropeptide role for ET-1 is supported by studies showing a variety of effects caused following its administration into different regions of the brain and by application to peripheral nerves. In addition there are studies proposing that ET-1 is implicated in a number of neural circuits where its transmitter affects range from a role in pain and temperature control to its action on the hypothalamo-neurosecretory system. While the effect of ET-1 on nerve tissue is beyond doubt, its action on nerve blood flow is often ignored. Here, we review data generated in a number of species and using a variety of experimental models. Studies range from those showing the distribution of ET-1 and its receptors in nerve tissue to those describing numerous neurally-mediated effects of ET-1.
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Ventura R, Aguiar J, Antunes-Rodrigues J, Varanda W. Nitric oxide modulates the firing rate of the rat supraoptic magnocellular neurons. Neuroscience 2008; 155:359-65. [DOI: 10.1016/j.neuroscience.2008.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 06/02/2008] [Accepted: 06/02/2008] [Indexed: 10/22/2022]
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15
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Saito T, Dayanithi G, Saito J, Onaka T, Urabe T, Watanabe TX, Hashimoto H, Yokoyama T, Fujihara H, Yokota A, Nishizawa S, Hirata Y, Ueta Y. Chronic osmotic stimuli increase salusin-beta-like immunoreactivity in the rat hypothalamo-neurohypophyseal system: possible involvement of salusin-beta on [Ca2+]i increase and neurohypophyseal hormone release from the axon terminals. J Neuroendocrinol 2008; 20:207-19. [PMID: 18047553 DOI: 10.1111/j.1365-2826.2007.01632.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Salusin-alpha and -beta were recently discovered as bioactive endogenous peptides. In the present study, we investigated the effects of chronic osmotic stimuli on salusin-beta-like immunoreactivity (LI) in the rat hypothalamo-neurohypophyseal system. We examined the effects of salusin-beta on synaptic inputs to the rat magnocellular neurosecretory cells (MNCs) of the supraoptic nucleus (SON) and neurohypophyseal hormone release from both freshly dissociated SONs and neurohypophyses in rats. Immunohistochemical studies revealed that salusin-beta-LI neurones and fibres were markedly increased in the SON and the magnocellular division of the paraventricular nucleus after chronic osmotic stimuli resulting from salt loading for 5 days and dehydration for 3 days. Salusin-beta-LI fibres and varicosities in the internal zone of the median eminence and the neurohypophysis were also increased after osmotic stimuli. Whole-cell patch-clamp recordings from rat SON slice preparations showed that salusin-beta did not cause significant changes in the excitatory and inhibitory postsynaptic currents of the MNCs. In vitro hormone release studies showed that salusin-beta evoked both arginine vasopressin (AVP) and oxytocin release from the neurohypophysis, but not the SON. In our hands, in the neurohypophysis, a significant release of AVP and oxytocin was observed only at concentrations from 100 nm and above of salusin-beta. Low concentrations below 100 nm were ineffective both on AVP and oxytocin release. We also measured intracellular calcium ([Ca(2+)](i)) increase induced by salusin-beta on freshly-isolated single nerve terminals from the neurohypophysis devoid of pars intermedia. Furthermore, this salusin-beta-induced [Ca(2+)](i) increase was blocked in the presence of high voltage activated Ca(2+)channel blockers. Our results suggest that salusin-beta may be involved in the regulation of body fluid balance by stimulating neurohypophyseal hormone release from nerve endings by an autocrine/paracrine mechanism.
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Affiliation(s)
- T Saito
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
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Batalhão ME, Moreto V, Stabile AM, Antunes-Rodrigues J, Carnio EC. Role of dexamethasone on vasopressin release during endotoxemic shock. ACTA ACUST UNITED AC 2008; 147:67-71. [PMID: 18243366 DOI: 10.1016/j.regpep.2008.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Revised: 11/23/2007] [Accepted: 01/02/2008] [Indexed: 11/18/2022]
Abstract
The present study was designed to assess the hypothesis that dexamethasone (DEX) through the control of nitric oxide (NO) synthesis could regulate the release of vasopressin (AVP), which plays an important role in the regulation of arterial pressure and plasma osmolality. Endotoxemic shock was induced by intravenous (i.v.) injection of 1.5 mg/kg lipopolisaccharide (LPS) in male Wistar rats weighing 250-300 g. After LPS administration, a group of animals were treated with DEX (1.0 mg/kg of body weight), whereas saline-injected rats served as controls. The LPS administration induced a significant decrease in mean arterial pressure (MAP) with a concomitant increase in heart rate (HR) (Delta VMAP: -16.1+/-4.2 mm Hg; Delta VHR: 47.3+/-8.1 bpm). An increase in plasma AVP concentration occurred and was present for 2 h after LPS administration (11.1+/-0.9 pg/mL) returning close to basal levels thereafter and remaining unchanged until the end of the experiment. When LPS was combined with i.v. administration of a low dose of DEX, we observed an attenuation in the drop of MAP (Delta VMAP: -2.2+/-1.9 mm Hg) and a decrease in NO plasma concentration [NO] after LPS administration (1098.1+/-68.1 microM) compared to [NO] after DEX administration (523.4+/-75.2 microM). However, this attenuation in the drop of MAP was accompanied by a decrease in AVP plasma concentration (3.7+/-0.4 pg/mL). These data suggest that AVP does not participate in the recovery of MAP when DEX is administered in this endotoxemic shock model.
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Affiliation(s)
- M E Batalhão
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14040-902, Ribeirão Preto, São Paulo, Brazil
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Calabrese V, Mancuso C, Calvani M, Rizzarelli E, Butterfield DA, Stella AMG. Nitric oxide in the central nervous system: neuroprotection versus neurotoxicity. Nat Rev Neurosci 2007; 8:766-75. [PMID: 17882254 DOI: 10.1038/nrn2214] [Citation(s) in RCA: 1010] [Impact Index Per Article: 59.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
At the end of the 1980s, it was clearly demonstrated that cells produce nitric oxide and that this gaseous molecule is involved in the regulation of the cardiovascular, immune and nervous systems, rather than simply being a toxic pollutant. In the CNS, nitric oxide has an array of functions, such as the regulation of synaptic plasticity, the sleep-wake cycle and hormone secretion. Particularly interesting is the role of nitric oxide as a Janus molecule in the cell death or survival mechanisms in brain cells. In fact, physiological amounts of this gas are neuroprotective, whereas higher concentrations are clearly neurotoxic.
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Affiliation(s)
- Vittorio Calabrese
- Department of Chemistry, Biochemistry and Molecular Biology Section, Faculty of Medicine, University of Catania, Catania, Italy.
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18
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Reis WL, Giusti-Paiva A, Ventura RR, Margatho LO, Gomes DA, Elias LLK, Antunes-Rodrigues J. Central nitric oxide blocks vasopressin, oxytocin and atrial natriuretic peptide release and antidiuretic and natriuretic responses induced by central angiotensin II in conscious rats. Exp Physiol 2007; 92:903-11. [PMID: 17513344 DOI: 10.1113/expphysiol.2007.037911] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The presence of nitric oxide synthase (NOS), the enzyme that catalyses the formation of nitric oxide (NO), in the circumventricular organs and magnocellular neurones suggests an important role of NO in the modulation of vasopressin (AVP) and oxytocin (OT) release. Intracerebroventricular (I.C.V.) injection of angiotensin II (Ang II) stimulates the release of AVP, OT and atrial natriuretic peptide (ANP), with the resultant antidiuretic and natriuretic effects. This study investigated the interaction between nitrergic and angiotensinergic pathways on the release of AVP, OT and ANP and on urinary volume and sodium excretion in water-loaded rats. Unanaesthetized, freely moving, male Wistar rats received two water loads followed by an injection into the lateral ventricle of an inhibitor of NOS (L-NAME), a NO donor [3-morpholinylsydnoneimine chloride (SIN-1) or S-nitroso-N-acetyl penicillamine (SNAP)] or vehicle (isotonic saline) and, 20 min after, they received a second I.C.V. injection of Ang II or vehicle. Injections of L-NAME or Ang II produced an increase in plasma levels of AVP, OT and ANP, a reduction in urinary volume and an increase in sodium excretion. Pretreatment with L-NAME enhanced the Ang II-induced increase in AVP, OT and ANP release, as well as the antidiuresis and natriuresis. Injection of SIN-1 or SNAP did not modify hormonal plasma levels and urinary parameters. In contrast SNAP blocked the AVP, OT and ANP release, as well as antidiuretic and natriuretic responses induced by ANG-II. Thus, the central nitrergic system can act to inhibit AVP, OT and ANP secretion and the antidiuretic and natriuretic effects in response to Ang II.
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Affiliation(s)
- Wagner Luis Reis
- Laboratory of Neuroendocrinology, Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Brazil
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19
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Li M, Vizzard MA, Jaworski DM, Galbraith RA. The weight loss elicited by cobalt protoporphyrin is related to decreased activity of nitric oxide synthase in the hypothalamus. J Appl Physiol (1985) 2006; 100:1983-91. [PMID: 16469935 DOI: 10.1152/japplphysiol.01169.2005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Administration of cobaltic protoporphyrin IX (CoPP) into the third ventricle of the brain by intracerebroventricular injection in rodents is known to result in transient hypophagia and remarkably prolonged weight loss. The mechanism of action of CoPP in eliciting these effects is unknown. It is known that nitric oxide plays a role in food intake and that the hyperphagia that results from a wide variety of genetic, physiological, and pharmacological stimuli can be blocked by the administration of inhibitors of the enzyme nitric oxide synthase (NOS). We demonstrate that intracerebroventricular administration of compounds that alter nitrergic tone can also change food ingestion and weight gain patterns in normophagic rats. We also demonstrate that CoPP decreases NOS activity but that it paradoxically increases neuronal NOS transcript expression and increases neuronal NOS protein content on Western blotting.
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Affiliation(s)
- Muyao Li
- Department of Medicine, University of Vermont, C209 Given Bldg., 89 Beaumont Ave., Burlington, Vermont 05405, USA
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20
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Tassorelli C, Greco R, Cappelletti D, Sandrini G, Nappi G. Comparative analysis of the neuronal activation and cardiovascular effects of nitroglycerin, sodium nitroprusside and l-arginine. Brain Res 2005; 1051:17-24. [PMID: 16005857 DOI: 10.1016/j.brainres.2005.05.067] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Revised: 05/15/2005] [Accepted: 05/18/2005] [Indexed: 11/24/2022]
Abstract
In this study, we compare the biological effects, Fos expression and cardiovascular responses induced in the rat, of different nitric oxide modulators (nitroglycerin, sodium nitroprusside and L-arginine). Nitroglycerin and sodium nitroprusside induced a similar pattern of neuronal activation in several areas, which include the paraventricular and supraoptic nuclei of the hypothalamus, central nucleus of the amygdala, parabrachial nucleus, locus coeruleus, ventrolateral medulla and nucleus tractus solitarius. However, only nitroglycerin activated the periaqueductal grey and nucleus trigeminalis caudalis. L-arginine-induced neuronal activation was restricted to the paraventricular and supraoptic nuclei of the hypothalamus. As regards cardiovascular effect, both nitroglycerin and sodium nitroprusside induced moderate hypotension (nitroglycerin: -23.3%, sodium nitroprusside: -24.3%) that lasted 40 min in the case of sodium nitroprusside and 80 min in the case of nitroglycerin. L-arginine did not significantly influence blood pressure. These data suggest that nitroglycerin, sodium nitroprusside and L-arginine are associated with different biological effects on both the central nervous system and the cardiovascular system. Of the NO-related drugs tested in this study, only nitroglycerin confirmed its ability to activate brainstem areas implicated in nociception.
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Affiliation(s)
- Cristina Tassorelli
- Laboratory of Pathophysiology of Integrative Autonomic Systems, IRCCS Institute of Neurology C. Mondino Foundation and University Centre for the Study of Adaptive Disorders and Headache (UCADH), Pavia, Italy.
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21
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Carnio EC, Stabile AM, Batalhão ME, Silva JS, Antunes-Rodrigues J, Branco LGS, Magder S. Vasopressin release during endotoxaemic shock in mice lacking inducible nitric oxide synthase. Pflugers Arch 2005; 450:390-4. [PMID: 15971084 DOI: 10.1007/s00424-005-1400-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Accepted: 02/16/2005] [Indexed: 11/30/2022]
Abstract
We tested the hypothesis that nitric oxide (NO) arising from the action of inducible nitric oxide synthase (iNOS) is responsible for the deficiency in vasopressin (AVP) release and consequent hypotension during endotoxaemic shock. Wild-type (WT) and iNOS knockout mice (iNOS(-/-)) were given either saline or Escherichia coli lipopolysaccharide (LPS, 1.0 mg/kg i.v., final volume 0.03 ml). Mean arterial blood pressure (MAP) was measured and plasma AVP levels determined before and after LPS or saline injection. In WT mice, MAP was significantly lower 2 h after LPS administration and remained low for the remainder of the 6-h observation period. AVP plasma levels were increased at the 2nd and 4th h of the experiment, returning thereafter to basal levels. Conversely, LPS injection in iNOS iNOS(-/-) mice elicited a sustained increase in plasma AVP concentration and attenuated the fall in blood pressure. These data indicate that NO arising from the iNOS plays an important inhibitory role in AVP release during endotoxaemia and may be responsible for the hypotension occurring during this vasodilatory shock.
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Affiliation(s)
- Evelin C Carnio
- Escola de Enfermagem de Ribeirão Preto, Universidade de São Paulo, 14040-902-Ribeirão Preto, São Paulo, Brazil.
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22
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Mineta K, Nomura M, Terado M, Fujimoto N, Sasaguri T, Ueta Y, Matsumoto T. Upregulation of corticotropin-releasing hormone gene expression in the paraventricular nucleus of cyclophosphamide-induced cystitis in male rats. Brain Res 2004; 1018:193-200. [PMID: 15276878 DOI: 10.1016/j.brainres.2004.05.063] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2004] [Indexed: 11/24/2022]
Abstract
We examined the effects of cyclophosphamide (CP)-induced cystitis on the expression of corticotropin-releasing hormone (CRH) mRNA in the paraventricular nucleus (PVN) and the serum levels of adrenocorticotropic hormone (ACTH) using in situ hybridization histochemistry and radioimmunoassay. In addition, the expression of AVP heteronuclear (hn) RNA and neuronal nitric oxide synthase (nNOS) mRNA was also examined in the PVN of a CP-induced cystitis model. We found that the levels of CRH mRNA were significantly increased in the PVN at 2 h after intraperitoneal administration of CP compared to those in saline-treated rats. The CRH mRNA levels in the PVN peaked at 12 h after CP administration and the levels were still significantly higher than those in saline-treated group at 24 h after CP administration. The serum ACTH levels in CP-treated group were also significantly higher compared to those in saline-treated group at any of the time points examined. Unlike previous findings showing upregulation of nNOS mRNA and AVP hnRNA under somatic nociceptive states, the levels of nNOS mRNA and AVP hnRNA were unchanged in the PVN following CP-induced cystitis, visceral nociceptive stimulation. These results suggest that visceral nociceptive stimulation as well as somatic nociceptive stimulation may activate the hypothalamo-pituitary axis but the hypothalamic neuroendocrine responses produced by visceral nociceptive stimulation may be different from those produced by somatic nociceptive stimulation.
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Affiliation(s)
- Kaori Mineta
- Department of Urology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahakanishi, Kitakyushu 807-8555, Japan
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23
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Abstract
Nitric oxide (NO), a free radical gas produced endogenously from the amino acid L-arginine by NO synthase (NOS), has important functions in modulating vasopressin and oxytocin secretion from the hypothalamo-neurohypophyseal system. NO production is stimulated during increased functional activity of magnocellular neurons, in parallel with plastic changes of the supraoptic nucleus (SON) and paraventricular nucleus. Electrophysiological data recorded from the SON of hypothalamic slices indicate that NO inhibits firing of phasic and non-phasic neurons, while L-NAME, an NOS inhibitor, increases their activity. Results from measurement of neurohypophyseal hormones are more variable. Overall, however, it appears that NO, tonically produced in the forebrain, inhibits vasopressin and oxytocin secretion during normovolemic, isosmotic conditions. During osmotic stimulation, dehydration, hypovolemia and hemorrhage, as well as high plasma levels of angiotensin II, NO inhibition of vasopressin neurons is removed, while that of oxytocin neurons is enhanced. This produces a preferential release of vasopressin over oxytocin important for correction of fluid imbalance. During late pregnancy and throughout lactation, fluid homeostasis is altered and expression of NOS in the SON is down- and up-regulated, respectively, in parallel with plastic changes of the magnocellular system. NO inhibition of magnocellular neurons involves GABA and prostaglandin synthesis and the signal-transduction mechanism is independent of the cGMP-pathway. Plasma hormone levels are unaffected by i.c.v. 1H-[1, 2, 4]oxadiazolo-[4,3-a]quinoxalin-1-one (a soluble guanylyl cyclase inhibitor) or 8-Br-cGMP administered to conscious rats. Moreover, cGMP does not increase in homogenates of the neural lobe and in microdialysates of the SON when NO synthesis is enhanced during osmotic stimulation. Among alternative signal-transduction pathways, nitrosylation of target proteins affecting activity of ion channels is considered.
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Affiliation(s)
- M Kadekaro
- Division of Neurosurgery, The University of Texas Medical Branch at Galveston, Galveston, TX 77555-0517, USA.
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Antunes-Rodrigues J, de Castro M, Elias LLK, Valença MM, McCann SM. Neuroendocrine control of body fluid metabolism. Physiol Rev 2004; 84:169-208. [PMID: 14715914 DOI: 10.1152/physrev.00017.2003] [Citation(s) in RCA: 336] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Mammals control the volume and osmolality of their body fluids from stimuli that arise from both the intracellular and extracellular fluid compartments. These stimuli are sensed by two kinds of receptors: osmoreceptor-Na+ receptors and volume or pressure receptors. This information is conveyed to specific areas of the central nervous system responsible for an integrated response, which depends on the integrity of the anteroventral region of the third ventricle, e.g., organum vasculosum of the lamina terminalis, median preoptic nucleus, and subfornical organ. The hypothalamo-neurohypophysial system plays a fundamental role in the maintenance of body fluid homeostasis by secreting vasopressin and oxytocin in response to osmotic and nonosmotic stimuli. Since the discovery of the atrial natriuretic peptide (ANP), a large number of publications have demonstrated that this peptide provides a potent defense mechanism against volume overload in mammals, including humans. ANP is mostly localized in the heart, but ANP and its receptor are also found in hypothalamic and brain stem areas involved in body fluid volume and blood pressure regulation. Blood volume expansion acts not only directly on the heart, by stretch of atrial myocytes to increase the release of ANP, but also on the brain ANPergic neurons through afferent inputs from baroreceptors. Angiotensin II also plays an important role in the regulation of body fluids, being a potent inducer of thirst and, in general, antagonizes the actions of ANP. This review emphasizes the role played by brain ANP and its interaction with neurohypophysial hormones in the control of body fluid homeostasis.
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Affiliation(s)
- José Antunes-Rodrigues
- Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil.
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25
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Giusti-Paiva A, Branco LGS, de Castro M, Antunes-Rodrigues J, Carnio EC. Role of nitric oxide in thermoregulation during septic shock: involvement of vasopressin. Pflugers Arch 2003; 447:175-80. [PMID: 14530975 DOI: 10.1007/s00424-003-1164-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2003] [Revised: 07/04/2003] [Accepted: 08/07/2003] [Indexed: 11/25/2022]
Abstract
We tested the hypothesis that the nitric oxide (NO) pathway in the central nervous system (CNS) plays a role in hypothermia, as well as in the febrile response during experimental septic shock, by regulating vasopressin (AVP) release. Experiments were performed on male Wistar rats treated with NG-nitro-L-arginine methyl ester (L-NAME), a non-selective NO synthase (NOS) inhibitor, injected intracerebroventricularly (250 microg/1 microl) 30 min before lipopolysaccharide (LPS) 1.5 mg/kg i.v. injection. One hour after LPS administration we observed a significant drop in body temperature (hypothermic response), followed by a temperature increase after the second hour (febrile response), which remained until the end of the experiment. Increased plasmatic AVP levels were concomitantly observed during hypothermia, nearly returning to basal levels during the febrile phase. When L-NAME was administered with LPS, plasmatic AVP concentrations remained high throughout the experiment, hypothermia was accentuated and the febrile response was abolished. Additionally, pre-treatment with beta-mercapto-beta,beta-cyclopentamethylenepropionyl1, O-Et-Tyr2, Val4, Arg8-vasopressin, an AVP V1 receptor blocker (10 microg/kg) administered i.v., reduced hypothermia and exacerbated the febrile response to endotoxin. In conclusion, our data indicate that the central NO pathway plays an inhibitory role in AVP release during experimental septic shock, which seems to be critical for the thermoregulation during this pathophysiological state.
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Affiliation(s)
- Alexandre Giusti-Paiva
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
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26
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Qadri F, Arens T, Schwarz EC, Häuser W, Dendorfer A, Dominiak P. Brain nitric oxide synthase activity in spontaneously hypertensive rats during the development of hypertension. J Hypertens 2003; 21:1687-94. [PMID: 12923401 DOI: 10.1097/00004872-200309000-00018] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Blockade of neuronal nitric oxide synthase (nNOS) in the brain induced an increase in mean arterial pressure of spontaneously hypertensive rats (SHR). We hypothesize that increased nitric oxide (NO) synthesis in the brain compensates for hypertension. Therefore, we measured NOS activity in different brain regions in SHR at prehypertensive, onset and established hypertension, and compared with age-matched Wistar-Kyoto (WKY) rats. METHOD NOS activity was measured by the ability of tissue homogenate to convert [3H]l-arginine to [3H]l-citrulline in a Ca2+- and NADPH-dependent manner. RESULTS NOS activity was impaired in the cerebral cortex and brainstem of prehypertensive SHR. At established hypertension, SHR showed an augmentation in NOS activity in hypothalamus and brainstem. Chronic treatment of SHR with the angiotensin-1 converting enzyme (ACE)-inhibitor, enalapril, and the AT(1) receptor antagonist, losartan, normalized NOS activity in the hypothalamus but not in the brainstem. Treatment with a peripheral vasodilator, hydralazine, did not affect NOS activity. CONCLUSION Attenuated NOS activity in the cortex and brainstem of prehypertensive SHR may play a role in the pathogenesis of hypertension. The upregulated NOS activity in the hypothalamus and brainstem of SHR possibly serves to compensate for hypertension. Hypothalamic, but not brainstem, NO is involved in antihypertensive effects of ACE inhibition and AT(1) receptor blockade. Since a blood pressure decrease per se had no effect on NOS activity, it appears that central sympathetic activity influenced by endogenous angiotensin II, rather than blood pressure, represents the stimulus for the increased NOS activity in the hypothalamus of SHR.
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Affiliation(s)
- Fatimunnisa Qadri
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany.
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27
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Yamaguchi K, Hama H. A study on the mechanism by which sodium nitroprusside, a nitric oxide donor, applied to the anteroventral third ventricular region provokes facilitation of vasopressin secretion in conscious rats. Brain Res 2003; 968:35-43. [PMID: 12644262 DOI: 10.1016/s0006-8993(02)04246-4] [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] [Indexed: 01/22/2023]
Abstract
We reported previously that sodium nitroprusside (SNP) applied to the anteroventral third ventricular region (AV3V), a pivotal area for autonomic functions, facilitates vasopressin (AVP) secretion in conscious rats. The aim of this study was to pursue the problems of whether nitric oxide (NO) generated from the agent may be responsible for the phenomenon, and whether it may be mediated by cyclic guanosine monophosphate (cGMP), the biosynthesis of which could reportedly be activated by NO. The infusion of SNP into the AV3V of conscious rats produced dose-related increases in plasma AVP, the maximal responses of which appeared at 5 min. Blood pressure and heart rate tended to rise at 15 min. The plasma osmolality, sodium, potassium or chloride did not show marked alteration following the SNP administration. Although the SNP solution was hypertonic and hypernatremic, AV3V application of hypertonic saline with a relatively higher osmolality and an equal sodium level was significantly less effective in augmenting plasma AVP. When injected into the lateral ventricle, SNP did not change plasma AVP and reduced arterial pressure, different from the results provoked by the AV3V application. The rise in plasma AVP in response to the AV3V application of SNP was diminished by preadministration of hemoglobin, a scavenger of NO, that did not affect the responses of the other variables. In contrast, pretreatment with methylene blue, an agent capable of antagonizing the potency of NO to activate guanylate cyclase, did not attenuate but potentiated the responses of both plasma AVP and arterial pressure to the AV3V infusion of SNP. Hemoglobin or methylene blue given alone into the AV3V did not affect any of the variables monitored. On the other hand, the AV3V injection of 8-bromo cGMP, a stable analogue of cGMP, was not potent for causing a significant rise in plasma AVP, in contrast to the notable AVP-enhancing effect of 8-bromo cAMP. Arterial pressure and heart rate were elevated by both of these agents, whereas the remaining variables were not altered. Histological inspection indicated that the infusion sites of the drugs in the AV3V had included areas such as the organum vasculosum of the lamina terminalis, median preoptic nucleus, medial preoptic nucleus and periventricular nucleus. On the basis of these results, we concluded that the AVP secretion prompted by the AV3V application of SNP may be attributable to NO, whereas its well-known ability to stimulate guanylate cyclase activity may hardly contribute to this phenomenon.
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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, Japan.
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Arebi N, Healey ZV, Bliss PW, Ghatei M, Van Noorden S, Playford RJ, Calam J. Nitric oxide regulates the release of somatostatin from cultured gastric rabbit primary D-cells. Gastroenterology 2002; 123:566-76. [PMID: 12145809 DOI: 10.1053/gast.2002.34749] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Neuronal nitric oxide synthase (nNOS) is present in gastric D-cells. Mucosal somatostatin is diminished in H. pylori gastritis, where production of nitric oxide (NO) is increased. Therefore, we investigated the role of NO in D-cell function and the effects of prolonged exposure of D-cells to NO. METHODS Rabbit gastric D-cells were cultured. Somatostatin-14 was measured after 2 hours to examine the effects of arginine, nitric oxide sythase (NOS) inhibitors, and NO donors. Some cells were preincubated with a slow releasing NO donor for 12 hours. Results are expressed as percentage of total cell content. Nitrate content was measured by chemiluminescent assay. RESULTS L-arginine increased somatostatin-14 release in the presence of CCK8 from 4.4% +/- 0.5% to 6.4% +/- 0.4% (P < 0.02), and this was accompanied by NO release from 27 +/- 7 micromol/L to 86 +/- 12 micromol/L (P = 0.001). D-arginine and L-lysine had no effect. NOS inhibitors LNNA, SMT, and 7NI significantly attenuated the stimulatory response to L-arginine. NO donors sodium nitroprusside (SNP), 1 mmol/L, and S-nitroso-N-acetyl-D-L-penicillamine, 0.1 mmol/L, significantly increased basal and cholecystokinin-8 (CCK8) stimulated somatostatin release. Oxyhemoglobin attenuated the effect of SNP but not of L-arginine. Neither cyclic guanosine monophosphate nor guanylate cyclase were involved in the response to NO. However, inhibition of adenosine diphosphate (ADP) ribosyltransferase significantly decreased the response to L-arginine. Preincubation for 12 hours with 150 micromol/L (Z)-1-[(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate; IP3, inositol triphosphate decreased the 2-hour cellular response to CCK8 and SNP. CONCLUSIONS NO regulates rabbit D-cells. Acute exposure stimulates somatostatin mediated by ADP ribosylation, whereas long-term exposure reduces cellular responses to stimuli. The latter pathway may be responsible for the suppression of somatostatin in H. pylori gastritis.
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Affiliation(s)
- Naila Arebi
- Department of Gastroenterology, Hammersmith Hospital, Imperial College School of Medicine, London, United Kingdom.
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Giusti-Paiva A, De Castro M, Antunes-Rodrigues J, Carnio EC. Inducible nitric oxide synthase pathway in the central nervous system and vasopressin release during experimental septic shock. Crit Care Med 2002; 30:1306-10. [PMID: 12072686 DOI: 10.1097/00003246-200206000-00025] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Septic shock is characterized by arteriolar vasodilation and hypotension. We have tested the hypothesis that nitric oxide arising from inducible nitric oxide synthase in the central nervous system is responsible for the deficiency in vasopressin release and consequent hypotension during experimental septic shock. METHODS AND RESULTS Septic shock was induced in male Wistar rats by intravenous injection of 1.5 mg/kg lipopolysaccharide. After lipopolysaccharide administration, we found a significant decrease in mean arterial pressure with a concomitant increase in heart rate, a significant decrease in diuresis, and a transitory decrease in body temperature. An increase in plasma vasopressin concentrations occurred in these animals and was present for 2 hrs after lipopolysaccharide administration, returning close to basal concentrations thereafter and remaining unchanged for the next 24 hrs. When lipopolysaccharide was combined with central administration of aminoguanidine, an inducible nitric oxide synthase inhibitor, we observed a sustained increase in plasma vasopressin concentration and in the maintenance of blood pressure at 4 and 6 hrs after lipopolysaccharide treatment compared with rats treated with lipopolysaccharide alone. CONCLUSION These data indicate that central nitric oxide arising from the inducible nitric oxide synthase pathway plays an important inhibitory role in vasopressin release during experimental septic shock and may be responsible for the hypotension occurring in this vasodilatory shock.
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Affiliation(s)
- Alexandre Giusti-Paiva
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto-SP, Brasil
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Mukherjee AB, Loesch A. Co-localisation of nitric oxide synthase and endothelin in the rat supraoptic nucleus. THE HISTOCHEMICAL JOURNAL 2002; 34:181-7. [PMID: 12495225 DOI: 10.1023/a:1020950700078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The co-localisation of neuronal nitric oxide synthase and endothelin-1 was studied in the rat supraoptic nucleus at the electron microscopy level. Double pre-embedding immunocytochemistry was performed using ExtrAvidin-horseradish peroxidase and immunogold-silver techniques. Immunoreactivities to neuronal nitric oxide synthase and endothelin-1 were co-localised in sub-populations of endocrine neurones (cell bodies) and dendrites. Double-labelled axon terminals making asymmetrical synapses on unlabelled dendrites were also observed. The findings are discussed in terms of the possible role and significance of nitric oxide and endothlin-1 in the hypothalamo-neurohypophysial system.
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Affiliation(s)
- Andrew B Mukherjee
- Department of Anatomy and Developmental Biology and Centre for Neuroscience, University College London, Gower Street, London WCIE 6BT, UK
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Abstract
The magnocellular neurosecretory cells (MNCs) in the supraoptic nucleus (SON) express multiple kinds of genes, including not only the classical hormones arginine vasopressin (AVP) and oxytocin (OXT), but also other physiologically active substances including neuropeptides, their receptors, and nitric oxide (NO) synthase, the rate-limiting enzyme in the synthesis of NO under physiological condition. For example, osmotic stimuli such as dehydration and chronic salt loading cause a wide range of changes of the expression levels of the genes and marked induction of the expression of the genes in the SON. The expression of the NO synthase gene in the SON under physiological conditions is reviewed.
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Affiliation(s)
- Yoichi Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan.
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Burbach JP, Luckman SM, Murphy D, Gainer H. Gene regulation in the magnocellular hypothalamo-neurohypophysial system. Physiol Rev 2001; 81:1197-267. [PMID: 11427695 DOI: 10.1152/physrev.2001.81.3.1197] [Citation(s) in RCA: 238] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The hypothalamo-neurohypophysial system (HNS) is the major peptidergic neurosecretory system through which the brain controls peripheral physiology. The hormones vasopressin and oxytocin released from the HNS at the neurohypophysis serve homeostatic functions of water balance and reproduction. From a physiological viewpoint, the core question on the HNS has always been, "How is the rate of hormone production controlled?" Despite a clear description of the physiology, anatomy, cell biology, and biochemistry of the HNS gained over the last 100 years, this question has remained largely unanswered. However, recently, significant progress has been made through studies of gene identity and gene expression in the magnocellular neurons (MCNs) that constitute the HNS. These are keys to mechanisms and events that exist in the HNS. This review is an inventory of what we know about genes expressed in the HNS, about the regulation of their expression in response to physiological stimuli, and about their function. Genes relevant to the central question include receptors and signal transduction components that receive and process the message that the organism is in demand of a neurohypophysial hormone. The key players in gene regulatory events, the transcription factors, deserve special attention. They do not only control rates of hormone production at the level of the gene, but also determine the molecular make-up of the cell essential for appropriate development and physiological functioning. Finally, the HNS neurons are equipped with a machinery to produce and secrete hormones in a regulated manner. With the availability of several gene transfer approaches applicable to the HNS, it is anticipated that new insights will be obtained on how the HNS is able to respond to the physiological demands for its hormones.
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Affiliation(s)
- J P Burbach
- Rudolf Magnus Institute for Neurosciences, Section of Molecular Neuroscience, Department of Medical Pharmacology, University Medical Center Utrecht, Utrecht, The Netherlands.
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Kurose T, Ueta Y, Nomura M, Yamaguchi K, Nagata S. Nociceptive stimulation increases NO synthase mRNA and vasopressin heteronuclearRNA in the rat paraventricular nucleus. Auton Neurosci 2001; 88:52-60. [PMID: 11474546 DOI: 10.1016/s1566-0702(01)00235-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nociceptive stimulation causes neuroendocrine responses such as arginine vasopressin (AVP) release and activation of the hypothalamo-pituitary-adrenal (HPA) axis. We examined the effects of nociceptive stimulation on the expression levels of neuronal nitric oxide synthase (nNOS) mRNA, heteronuclear (hn)RNA for AVP and AVP mRNA in the rat paraventricular nucleus (PVN) and supraoptic nucleus (SON), using in situ hybridization histochemistry. For nociceptive stimulation, formalin (5%) or saline was injected subcutaneously (s.c.) into the bilateral hind paws of rats. The expression of the nNOS gene in the PVN was significantly increased 2 and 6 h after s.c. injection of formalin in comparison with that in untreated and saline injected rats. The expression of the nNOS gene in the SON did not change in the untreated, saline- and formalin-injected rats. The AVP hnRNA in the PVN and SON was also significantly increased 15, 30 min and 2 h after s.c. injection of formalin, though AVP mRNA did not change at any time points that we studied. Plasma concentration of AVP was significantly increased 15 min after s.c. injection of formalin. These results suggest that NO in the PVN may be involved in nociceptive stimulation-induced neuroendocrine responses.
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Affiliation(s)
- T Kurose
- Department of Mental Health, University of Occupational and Environmental Health, Kitakyushu, Japan.
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Navarra P, Vairano M, Costa A, Grossman A. The roles of carbon monoxide and nitric oxide in the control of the neuroendocrine stress response: complementary or redundant. Stress 2001; 4:3-11. [PMID: 22432123 DOI: 10.3109/10253890109001139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
There is widespread evidence in favour of nitric oxide (NO) acting as a gaseous neurotransmitter in the central nervous system, diffusing from its cells of origin and affecting surrounding neuronal tissue in evanescent three-dimensional waves. This is also true of the hypothalamus, where amongst other activities NO inhibits stimulation of corticotrophin-releasing hormone (CRH) and vasopressin release by inflammatory stressors, effects thought to be mediated by binding with soluble guanylate cyclase (sGC). Carbon monoxide is being increasingly recognised as another gaseous neuromodulator, but with principal effects on other hemoproteins such as cyclo-oxygenase, and a distinctly different profile of localisation.NO is predominantly a pro-inflammatory agent in the periphery while CO is often anti-inflammatory. In the hypothalamus, the actions of CO are also distinct from those of NO,with marked antagonistic effects on the inflammatory release of vasopressin, both in vitro and in vivo, but with little involvement in the regulation of CRH. Thus, it would appear that these apparently similar gases exert quite distinct and separate effects, although they cause broadly similar overall changes in the secretion of neuroendocrine stress hormones. We conclude that these two gases may play significant but different roles in the control of the neuroendocrine stress response, but one common feature may be attenuation of inflammation-induced release of stress hormones.
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Affiliation(s)
- P Navarra
- Institute of Pharmacology, Catholic University Medical School, Rome, Italy
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Anai H, Ueta Y, Serino R, Nomura M, Nakashima Y, Yamashita H. Activation of hypothalamic neuronal nitric oxide synthase in lithium-induced diabetes insipidus rats. Psychoneuroendocrinology 2001; 26:109-20. [PMID: 11087959 DOI: 10.1016/s0306-4530(00)00030-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The expression of the neuronal nitric oxide synthase (nNOS) gene in the paraventricular (PVN) and supraoptic nuclei (SON) in rats with lithium (Li)-induced polyuria was examined by using in situ hybridization histochemistry. The state of the thyroid axis in these rats was also examined by in situ hybridization histochemistry for thyrotropin-releasing hormone (TRH) and thyroid-stimulating hormone (TSH) mRNAs and radioimmunoassay for circulating thyroid hormones. Adult male Wistar rats consuming a diet that contained LiCl (60 mmol/kg) for 4 weeks developed remarkable polyuria. The urine in the Li-treated rats was hypotonic and had a large volume and low ionic concentration. The nNOS mRNA in the PVN and SON was significantly increased in the Li-treated rats in comparison with that in control. The increased levels of the nNOS mRNA in the PVN and SON were confirmed by NADPH-diaphorase histochemical staining. There were no differences of TRH mRNA in the PVN, TSH mRNA in the anterior pituitary and plasma concentrations of free T3 and free T4 between Li-treated rats and control rats. These results suggest that Li-induced diabetes insipidus may activate nNOS in the PVN and SON without change of the thyroid axis.
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Affiliation(s)
- H Anai
- Second Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, 807-8555, Kitakyushu, Japan
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Costa A, Nappi RE, Polatti F, Poma A, Grossman AB, Nappi G. Stimulating effect of HIV-1 coat protein gp120 on corticotropin-releasing hormone and arginine vasopressin in the rat hypothalamus: involvement of nitric oxide. Exp Neurol 2000; 166:376-84. [PMID: 11085902 DOI: 10.1006/exnr.2000.7502] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Subjects with human immunodeficiency virus type 1 (HIV-1) infection display increased activity of the hypothalamo-pituitary-adrenal (HPA) axis, which may play a role in both HIV-related neurodegenerative processes and disease progression. It has been speculated that the HIV coat protein gp120 may be responsible for these changes, and previous experimental evidence in both transgenic and nontransgenic mice supports this view. We speculated that one of the effects of gp120 in the CNS is to act within the hypothalamus to affect both corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP), the principal regulators of HPA axis. We therefore administered i.p. gp120 (100 ng/rat) or vehicle to male Wistar rats and then detected Fos protein (an index of neuronal activation), CRH, and AVP immunoreactivity in the cellular compartments of the hypothalamic paraventricular nucleus (PVN). In addition, we tested the direct effect of various concentrations of gp120 on the release of CRH and AVP from rat hypothalamic explants maintained in vitro. Any modulation of gp120 effects by nitric oxide (NO) pathways was also sought by coadministering i.p. to rats or adding to the hypothalamic preparations the NO synthase inhibitor N(G)-methyl-l-arginine (l-NMMA). Gp120 induced the expression of Fos protein in both the parvo- and the magnocellular PVN, which was significantly attenuated by l-NMMA 10(-6) nM/L (P < 0.001 vs gp120 alone). Double immunochemistry showed costaining for Fos protein and CRH or AVP in the PVN following gp120; the number of double-labeled CRH and AVP cells for Fos protein was markedly reduced (P < 0.001) by coadministration of l-NMMA 10(-6) nM/L. In the in vitro studies, addition of gp120 to the hypothalamic explants in the dose range of 10 pM-1 nM resulted in a clear stimulation of both CRH and AVP release (P < 0.05-0.001 compared to control); in the presence of l-NMMA at 10-fold higher concentrations the stimulatory effect of gp120 on the release of both peptides was completely lost. It would therefore appear that gp120 activates CRH and AVP-producing neurons in the hypothalamic PVN and stimulates the release of both peptides in vitro via NO-dependent mechanisms. These findings, in line with previous evidence, further suggest that the increased activity of the HPA axis associated with HIV infection may be of central origin, due to the effects of gp120 on hypothalamic CRH and AVP release.
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Affiliation(s)
- A Costa
- Laboratory of Neuroendocrinology, Institute of Neurology IRCCS C. Mondino, Italy
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37
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Otukonyong EE, Okere CO, Johnstone LE, Murata T, Kaba H, Higuchi T. Effect of suckling on NADPH-diaphorase (Nitric oxide synthase, NOS) reactivity and NOS gene expression in the paraventricular and supraoptic nuclei of lactating rats. J Neuroendocrinol 2000; 12:1001-8. [PMID: 11012841 DOI: 10.1046/j.1365-2826.2000.00548.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study examined the effect of suckling on nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d, a histochemical marker for nitric oxide synthase, NOS) reactivity and neuronal NOS mRNA expression in the paraventricular (PVN) and supraoptic (SON) nuclei of lactating rats. Freely nursing (non-separated) dams and those separated from pups for 12 h and then reunited for 0, 15, 30, 60, 90, 120 and 180 min were used for the study. Dams separated from pups and sacrificed at time zero (without reunion) showed a significant decrease in NADPH-d staining and NADPH-d positive cells as well as in the NOS mRNA expression in the PVN and SON compared to that observed in non-separated dams. Reunion with pups and restoration of suckling significantly increased NADPH-d reactivity after 15, 30, 60 min, but not after 90, 120 and 180 min compared to non-reunited pups-deprived dams. A pattern of NADPH-d reactivity and neuronal NOS mRNA expression indistinguishable from that observed during free lactation was reinstated shortly (15 min) after the restoration of suckling stimulus, suggesting that the NADPH-d reactivity in lactation depends on the presence of the suckling stimulus. These results show that suckling stimulus may play a modulatory role in the regulation of NOS reactivity in the magnocellular neurones of the hypothalamic PVN and SON during lactation.
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Affiliation(s)
- E E Otukonyong
- Department of Physiology, Kochi Medical School, Nankoku, Kochi, Japan.
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Kim CK, Rivier CL. Nitric oxide and carbon monoxide have a stimulatory role in the hypothalamic-pituitary-adrenal response to physico-emotional stressors in rats. Endocrinology 2000; 141:2244-53. [PMID: 10830314 DOI: 10.1210/endo.141.6.7500] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We tested the hypothesis that nitric oxide and carbon monoxide, which are produced in the brain by nitric oxide synthase (NOS) and heme oxygenase (HO), modulate the hypothalamic-pituitary-adrenal response to physico-emotional stressors by acting at the hypothalamus. Accordingly, we determined 1) whether the intracerebroventricular (icv) injection of NOS or HO inhibitors at doses that were confined to the brain attenuated electroshock-induced ACTH release; and 2) whether the decreases in this ACTH response were concurrent with decreases in NOS or HO activity levels at the hypothalamus. Icv injection of the NOS inhibitor Nomega-nitro-L-arginine-methylester (L-NAME; 50 microg) or the HO inhibitor tin protoporphyrin (SnPP; 20-25 microg) significantly blunted the plasma ACTH response to a 45-min session of intermittent electroshocks. Importantly, in these same animals there were concurrent decreases in hypothalamic NOS or HO activities, respectively. There were little or no effects of these inhibitors on anterior pituitary NOS or HO activities, indicating that there was only minimal leakage of the drug from the brain after icv administration. The specificity of action of these inhibitors was confirmed by the fact that SnPP did not affect NOS activity, and L-NAME did not affect HO activity. Finally, L-NAME produced no effect, whereas SnPP produced only transient increases in blood pressure, suggesting that these inhibitors do not affect activity indirectly through alterations in blood pressure. These data support the hypothesis that in the whole animal, both NO and CO exert a stimulatory influence on the acute ACTH response to physico-emotional stressors, and that the hypothalamus is the critical site of their actions.
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Affiliation(s)
- C K Kim
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, California 92037, USA
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Li Z, Hatton GI. Histamine suppresses non-NMDA excitatory synaptic currents in rat supraoptic nucleus neurons. J Neurophysiol 2000; 83:2616-25. [PMID: 10805662 DOI: 10.1152/jn.2000.83.5.2616] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Whole cell patch-clamp recordings were obtained from supraoptic neurons to investigate the effects of histamine on excitatory postsynaptic currents evoked by electrical stimulation of areas around the posterior supraoptic nucleus. When cells were voltage-clamped at -70 mV, evoked excitatory postsynaptic currents had amplitudes of 88.4 +/- 9.6 pA and durations of 41.1 +/- 3.0 ms (mean +/- SE; n = 43). With twin stimulus pulses (20 Hz) used, paired-pulse facilitation ratios were 1.93 +/- 0.12. Bath application of 6-cyano-7-nitroquinoxalene-2,3-dione (CNQX) abolished synaptic currents. Histamine at concentrations approximately 0.1-10 microM reversibly suppressed excitatory postsynaptic currents in all supraoptic neurons tested. Within 2 min after application of (10 microM) histamine, current amplitudes and durations decreased by 61. 5 and 31.0%, respectively, with little change in the paired-pulse facilitation ratio. Dimaprit or imetit (H(2) or H(3) receptor agonists) did not reduce synaptic currents, whereas pyrilamine (H(1) receptor antagonist) blocked histamine-induced suppression of synaptic currents. When patch electrodes containing guanosine 5'-O-(2-thiodiphosphate) (GDP-beta-S) were used to record cells, histamine still suppressed current amplitudes by 49.1% and durations by 41.9%. Similarly, intracellular diffusion of bis-(o-aminophenoxy)-N,N,N',N'-tetraacetic acid (BAPTA) and H(7) did not abolish histamine-induced suppression of synaptic currents, either. Bath perifusion of 8-bromo-quanosine 3',5'-cyclic monophosphate reduced current amplitudes by 32.3% and durations by 27.9%. After bath perfusion of slices with N(omega)-nitro-L-arginine methyl ester (L-NAME), histamine injection decreased current amplitudes only by 31.9%, much less than the inhibition rate in control (P < 0.01). In addition, histamine induced little change in current durations and paired-pulse facilitation ratios, representing a partial blockade of histamine effects on synaptic currents by L-NAME. In supraoptic neurons recorded using electrodes containing BAPTA and perifused with L-NAME, the effects of histamine on synaptic currents were completely abolished. Norepinephrine injection reversibly decreased current amplitudes by 39.1% and duration by 64.5%, with a drop in the paired-pulse facilitation ratio of 47.9%. Bath perifusion of L-NAME, as well as intracellular diffusion of GDP-beta-S, 1-(5-isoquinolinylsulfonyl)-2-methyl-piperazine, or BAPTA, failed to block norepinephrine-induced suppression of evoked synaptic currents. The present results suggest that histamine suppresses non-N-methyl-D-aspartate synaptic currents in supraoptic neurons through activation of H(1) receptors. It is possible that histamine first acts at supraoptic cells (perhaps both neuronal and nonneuronal) and induces the production of nitric oxide, which then diffuses to nearby neurons and modulates synaptic transmission by a postsynaptic mechanism.
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Affiliation(s)
- Z Li
- Department of Neuroscience, University of California, Riverside, California 92521, USA
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40
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Dhandapani KM, Brann DW. The role of glutamate and nitric oxide in the reproductive neuroendocrine system. Biochem Cell Biol 2000. [DOI: 10.1139/o00-015] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The preovulatory surge of gonadotropin releasing hormone (GnRH) is essential for mammalian reproduction. Recent work has implicated the neurotransmitters glutamate and nitric oxide as having a key role in this process. Large concentrations of glutamate are found in several hypothalamic nuclei known to be important for GnRH release and glutamate receptors are also located in these key hypothalamic nuclei. Administration of glutamate agonists stimulate GnRH and LH release, while glutamate receptor antagonists attenuate the steroid-induced and preovulatory LH surge. Glutamate has also been implicated in the critical processes of puberty, hormone pulsatility, and sexual behavior. Glutamate is believed to elicit many of these effects by activating the release of the gaseous neurotransmitter, nitric oxide (NO). NO potently stimulates GnRH by activating a heme containing enzyme, guanylate cyclase, which in turn leads to increased production of cGMP and GnRH release. Recent work has focused on identifying anchoring and (or) clustering proteins that target glutamate receptors to the synapse and couple the glutamate-NO neurotransmission system. The present review will discuss these new findings, as well as the role of glutamate and nitric oxide in important mammalian reproductive events, with a focus on the hypothalamic control of preovulatory GnRH release. Key words: glutamate, nitric oxide, GnRH, postsynaptic density, hypothalamus.
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Shibuya I, Kabashima N, Ibrahim N, Setiadji SV, Ueta Y, Yamashita H. Pre- and postsynaptic modulation of the electrical activity of rat supraoptic neurones. Exp Physiol 2000; 85 Spec No:145S-151S. [PMID: 10795917 DOI: 10.1111/j.1469-445x.2000.tb00018.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The release of vasopressin and oxytocin is regulated by the electrical activity of magnocellular neurosecretory cells in the supraoptic and paraventricular nuclei, which is under the control of a great variety of neurotransmitters and neuromodulators. The major neural signals to the supraoptic nucleus are from excitatory glutamate inputs and inhibitory GABA inputs. In recent studies, the voltage-clamp mode of the whole-cell patch-clamp technique has been applied to slice preparations from rat hypothalamus to monitor synaptic inputs to supraoptic neurones. Spontaneous excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs) are abolished by CNQX and picrotoxin, respectively, but are insensitive to tetrodotoxin, indicating that they represent quantal release of glutamate and GABA, respectively, from nerve terminals of presynaptic neurones. GABA and glutamate show remarkable suppressive effects on both EPSCs and IPSCs via presynaptic GABA(B) and mGlu receptors, respectively. Noradrenaline, which excites supraoptic neurones via postsynaptic alpha1-receptors, also suppresses IPSCs and potentiates EPSCs. On the other hand, prostaglandin E2, which excites supraoptic neurones via postsynaptic prostaglandin E2 (EP) receptors of the EP4 subclass, also suppresses IPSCs via EP3 receptors but has little effect on EPSCs. Thus pre- and postsynaptic mechanisms may act cooperatively to excite supraoptic neurones. Nitric oxide, which inhibits supraoptic neurones, potentiates IPSCs without affecting EPSCs. This provides another example for the preferential modulation of IPSCs of supraoptic neurones. On the other hand, PACAP, which causes a long-lasting increase in the firing frequency via the postsynaptic receptors, has no effect on EPSCs and IPSCs, suggesting that some ligands act only at postsynaptic receptors. Thus multiple patterns for pre- and postsynaptic modulation are present in the supraoptic nucleus, and the electrical activity of supraoptic neurones is regulated via complex mechanisms at both pre- and postsynaptic sites.
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Affiliation(s)
- I Shibuya
- Department of Physiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan.
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42
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Ozaki M, Shibuya I, Kabashima N, Isse T, Noguchi J, Ueta Y, Inoue Y, Shigematsu A, Yamashita H. Preferential potentiation by nitric oxide of spontaneous inhibitory postsynaptic currents in rat supraoptic neurones. J Neuroendocrinol 2000; 12:273-81. [PMID: 10718923 DOI: 10.1046/j.1365-2826.2000.00448.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Magnocellular neurones in the supraoptic nucleus and paraventricular nucleus express mRNA for nitric oxide synthase (NOS) and the expression becomes more prominent when the release of vasopressin or oxytocin is stimulated. It has also been reported that NO donors inhibit the electrical activity of supraoptic nucleus neurones, but the mechanism involved in the inhibition remains unclear. In the present study, to know whether modulation of synaptic inputs into supraoptic neurones is involved in the inhibitory effect of NO, we measured spontaneous excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs) from rat supraoptic nucleus neurones in slice preparations identified under a microscope using the whole-cell mode of the slice-patch-clamp technique. The NO donor, S-nitroso-N-acetylpenicillamine (SNAP), reversibly increased the frequency of spontaneous IPSCs mediated by GABAA receptors, without affecting the amplitude, indicating that NO potentiated IPSCs via a presynaptic mechanism. The NO scavenger, haemoglobin, suppressed the potentiation of IPSCs by SNAP. On the other hand, SNAP did not cause significant effects on EPSCs mediated by non-NMDA glutamate receptors. The membrane permeable analogue of cGMP, 8-bromo cGMP, caused a significant reduction in the frequency and amplitude of both IPSCs and EPSCs. The results suggest that NO preferentially potentiates the inhibitory synaptic inputs into supraoptic nucleus neurones by acting on GABA terminals in the supraoptic nucleus, possibly via a cGMP-independent mechanism. The potentiation may, at least in part, account for the inhibitory action of NO on the neural activity of supraoptic neurones.
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Affiliation(s)
- M Ozaki
- Department of Physiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
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43
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González de Aguilar JL, Gordon JW, René F, Lutz-Bucher B, Kienlen-Campard P, Loeffler JP. A mouse model of familial amyotrophic lateral sclerosis expressing a mutant superoxide dismutase 1 shows evidence of disordered transport in the vasopressin hypothalamo-neurohypophysial axis. Eur J Neurosci 1999; 11:4179-87. [PMID: 10594643 DOI: 10.1046/j.1460-9568.1999.00840.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal, paralytic disorder that primarily affects motoneurons. By combining physiological and morphological approaches, we examined the effect of a murine superoxide dismutase 1 (SOD1) mutation (G86R), which induces neurological disorders resembling human familial ALS (FALS), on the arginine vasopressin (AVP) hypothalamo-neurohypophysial axis, an unmyelinated tract poor in neurofilaments. First, we observed that G86R mice progressively consumed more water than wild-type littermates. Furthermore, levels of plasma AVP and neurohypophysial AVP content were decreased in the SOD1 mutant mice, whereas the amount of hypothalamic AVP increased in an age-dependent manner. However, hypothalamic AVP mRNA levels were not significantly modified in these animals. At the ultrastructural level, we found that the neurohypophysis of G86R mice had a decreased number of neurosecretory axons. Conversely, the presence of large axon swellings was more pronounced in the SOD1 mutant mice. In addition, the size of neurosecretory granules was higher in G86R than in wild-type animals. All these findings strongly suggest that the FALS-associated SOD1 mutation injures the hypothalamo-neurohypophysial axis by provoking early, progressive disturbances in the axonal transport of neurosecretory products from neuronal perikarya to nerve terminals. This blockade could ultimately result in degeneration of the tract, as proposed for the myelinated, neurofilament-enriched motor axons affected by ALS.
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Affiliation(s)
- J L González de Aguilar
- Laboratoire de Neurophysiologie Cellulaire et Intégrée, UMR CNRS, Université Louis Pasteur, Strasbourg, France
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Fujisawa Y, Mori N, Yube K, Miyanaka H, Miyatake A, Abe Y. Role of nitric oxide in regulation of renal sympathetic nerve activity during hemorrhage in conscious rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:H8-14. [PMID: 10409175 DOI: 10.1152/ajpheart.1999.277.1.h8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of inhibition of nitric oxide (NO) synthesis on the responses of blood pressure (BP), heart rate (HR), and renal sympathetic nerve activity (RSNA) during hemorrhaging was examined with the use of an NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), in conscious rats. In the 0.9% saline group, hemorrhage (10 ml/kg body wt) did not alter BP but significantly increased HR and RSNA by 88 +/- 12 beats/min and 67 +/- 12%, respectively. Intravenous infusion of L-NAME (50 microg. kg(-1). min(-1)) significantly attenuated these tachycardic and sympathoexcitatory responses to hemorrhage (14 +/- 7 beats/min and 26 +/- 12%, respectively). Pretreatment of L-arginine (87 mg/kg) recovered the attenuation of HR and RSNA responses induced by L-NAME (92 +/- 6 beats/min and 64 +/- 10%, respectively). L-NAME by itself did not alter the baroreceptor reflex control of HR and RSNA. Hemorrhage increased the plasma vasopressin concentration, and its increment in the L-NAME-treated group was significantly higher than that in the 0.9% saline group. Pretreatment with the vascular arginine vasopressin V(1)-receptor antagonist OPC-21268 (5 mg/kg) recovered the attenuation of RSNA response induced by L-NAME (54 +/- 7%). These results indicate that NO modulated HR and RSNA responses to hemorrhage but did not directly affect the baroreceptor reflex arch. It can be assumed that NO modulated the baroreflex function by altering the secretion of vasopressin induced by hemorrhage.
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Affiliation(s)
- Y Fujisawa
- Research Equipment Center, Kagawa Medical University, Kagawa 761-0793, Japan
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Yang W, Oskin O, Krukoff TL. Immune stress activates putative nitric oxide-producing neurons in rat brain: cumulative effects with restraint. J Comp Neurol 1999; 405:380-7. [PMID: 10076932 DOI: 10.1002/(sici)1096-9861(19990315)405:3<380::aid-cne7>3.0.co;2-g] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Immune and restraint stresses induce changes in the hypothalamo-pituitary-adrenal axis activity and autonomic function. In the hypothalamus, the paraventricular nucleus (PVN) plays an integral role, and nitric oxide (NO) is hypothesized to participate in this process. We used 1) intravenous injections of lipopolysaccharide (LPS, 125 microg/kg) to identify activated (Fos-positive) putative NO-producing neurons, 2) retrograde tracing to determine if autonomic medullary regions signal the PVN to mediate this activation, and 3) intravenous LPS injections plus restraint stress to determine if responses to restraint are altered by the presence of immune stress. At 2 hours after LPS injections, approximately 15% of putative NO-producing neurons were activated in the nucleus of the tractus solitarius (NTS) and ventrolateral medulla (VLM); about half of the putative NO neurons in the PVN were activated. In LPS + restraint rats, the percentage of activated putative NO neurons in the PVN was not significantly different from LPS-treated rats, but the numbers of putative NO neurons and activated NO neurons per section increased significantly. Retrogradely labeled neurons were found mostly in the middle NTS and VLM, and about 75% were activated. No neurons in the NTS or VLM were triple labeled. The results show that putative NO-producing neurons in the PVN, NTS, and VLM are activated by circulating LPS. However, the LPS-induced signaling to the PVN likely occurs through pathways other than the NO network of neurons in NTS or VLM. Finally, superimposition of restraint stress onto animals already exposed to immune stress stimulates the NO system in the PVN to a greater extent than either stress alone.
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Affiliation(s)
- W Yang
- Department of Cell Biology and Anatomy, Faculty of Medicine, University of Alberta, Edmonton, Canada
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Bugajski J, Gadek-Michalska A, Borycz J, Głód R. Social stress inhibits the nitric oxide effect on the corticotropin-releasing hormone- but not vasopressin-induced pituitary-adrenocortical responsiveness. Brain Res 1999; 817:220-5. [PMID: 9889372 DOI: 10.1016/s0006-8993(98)01209-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Putative involvement of endogenous nitric oxide (NO) in the corticotropin-releasing hormone (CRH, 1 microg/kg i.p.)- and vasopressin (AVP, 5 microg/kg i.p.)-induced ACTH and corticosterone secretion was investigated in both non-stressed and crowded rats. The NO synthase blocker Nomega-nitro-l-arginine (l-NNA, 2 mg/kg i.p. ) significantly augmented the AVP-induced ACTH and corticosterone secretion in control and stressed rats, but it increased the CRH-induced ACTH response only in control rats. Crowding stress did not affect the l-NNA evoked increase in AVP-induced hormone responses, but it abolished the CRH-induced ACTH response.
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Affiliation(s)
- J Bugajski
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, 12 Sm&ecedil;tna Street, 31-343, Kraków, Poland.
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Turnbull AV, Rivier CL. Regulation of the hypothalamic-pituitary-adrenal axis by cytokines: actions and mechanisms of action. Physiol Rev 1999; 79:1-71. [PMID: 9922367 DOI: 10.1152/physrev.1999.79.1.1] [Citation(s) in RCA: 808] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glucocorticoids are hormone products of the adrenal gland, which have long been recognized to have a profound impact on immunologic processes. The communication between immune and neuroendocrine systems is, however, bidirectional. The endocrine and immune systems share a common "chemical language," with both systems possessing ligands and receptors of "classical" hormones and immunoregulatory mediators. Studies in the early to mid 1980s demonstrated that monocyte-derived or recombinant interleukin-1 (IL-1) causes secretion of hormones of the hypothalamic-pituitary-adrenal (HPA) axis, establishing that immunoregulators, known as cytokines, play a pivotal role in this bidirectional communication between the immune and neuroendocrine systems. The subsequent 10-15 years have witnessed demonstrations that numerous members of several cytokine families increase the secretory activity of the HPA axis. Because this neuroendocrine action of cytokines is mediated primarily at the level of the central nervous system, studies investigating the mechanisms of HPA activation produced by cytokines take on a more broad significance, with findings relevant to the more fundamental question of how cytokines signal the brain. This article reviews published findings that have documented which cytokines have been shown to influence hormone secretion from the HPA axis, determined under what physiological/pathophysiological circumstances endogenous cytokines regulate HPA axis activity, established the possible sites of cytokine action on HPA axis hormone secretion, and identified the potential neuroanatomic and pharmacological mechanisms by which cytokines signal the neuroendocrine hypothalamus.
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Affiliation(s)
- A V Turnbull
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, California, USA
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Ueta Y, Levy A, Lightman SL, Hara Y, Serino R, Nomura M, Shibuya I, Hattori Y, Yamashita H. Hypovolemia upregulates the expression of neuronal nitric oxide synthase gene in the paraventricular and supraoptic nuclei of rats. Brain Res 1998; 790:25-32. [PMID: 9593810 DOI: 10.1016/s0006-8993(97)01531-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have examined the effects of isotonic hypovolemia on the expression of the neuronal nitric oxide synthase (nNOS) gene in the paraventricular (PVN) and supraoptic nuclei (SON) of the rat, using in situ hybridization histochemistry with a 35S-labelled oligodeoxynucleotide probe complementary to nNOS mRNA. Intraperitoneal (i.p.) administration of polyethylene glycol (PEG) (MW 4000, 20 ml/kg body weight) dissolved in 0.9% saline (20% w/v) induced isotonic hypovolemia. The expression of the nNOS gene in the PVN and SON 6 h after i.p. administration of PEG was increased significantly in comparison with controls. The dual staining for NADPH diaphorase activity and Fos-like immunoreactivity (Fos-LI) showed that at 3 and 6 h after i.p. administration of PEG, a subpopulation of NADPH diaphorase-positive cells in the PVN and SON exhibited nuclear Fos-LI. These results suggest that NO in the PVN and SON may be involved in the neuroendocrine and autonomic responses to non-osmotic hypovolemia.
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Affiliation(s)
- Y Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
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Tanaka M, Ikeda T, Hayashi S, Iijima N, Amaya F, Hisa Y, Ibata Y. Nitrergic neurons in the medial amygdala project to the hypothalamic paraventricular nucleus of the rat. Brain Res 1997; 777:13-21. [PMID: 9449408 DOI: 10.1016/s0006-8993(97)00948-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We investigated nitric oxide (NO)-producing neurons in the amygdala which project to the hypothalamic paraventricular nucleus (PVN) of the rat using retrograde tracing and NADPH-diaphorase histochemistry. Numerous NADPH-diaphorase positive neurons with moderate staining were observed mainly in the medial amygdaloid nucleus. We confirmed that these NADPH-diaphorase positive neurons are identical to NO synthase (NOS)-immunoreactive neurons by double staining with NADPH-diaphorase histochemistry and NOS immunocytochemistry. Most neurons containing cholera toxin B subunit (CTb) - which was retrogradely transported from the PVN - were observed in the medial amygdaloid nucleus. In other amygdaloid nuclei, they were observed much less in the central nucleus, basomedial and anterior cortical nucleus. Double labeled neurons by NADPH-diaphorase and CTb were also identified mostly in the medial nucleus. Approximately 40% of the neurons projecting to the PVN were nitrergic neurons and 16% of NADPH-diaphorase positive neurons in the medial nucleus were revealed to project to the PVN. These results suggest that NO-producing neurons in the medial amygdala directly innervate PVN neurons and regulate neuroendocrine systems such as vasopressin and corticotropin releasing factor release.
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Affiliation(s)
- M Tanaka
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Japan
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50
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Tsuchiya T, Kishimoto J, Koyama J, Ozawa T. Modulatory effect of L-NAME, a specific nitric oxide synthase (NOS) inhibitor, on stress-induced changes in plasma adrenocorticotropic hormone (ACTH) and corticosterone levels in rats: physiological significance of stress-induced NOS activation in hypothalamic-pituitary-adrenal axis. Brain Res 1997; 776:68-74. [PMID: 9439797 DOI: 10.1016/s0006-8993(97)00942-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We investigated whether NG-nitro-L-arginine methyl ester (L-NAME), a specific inhibitor of nitric oxide synthase (NOS), can modify the stress-induced adrenocorticotropic hormone (ACTH) and corticosterone responses, because we found that immobilization-induced stress increases NOS mRNA and protein levels and enzyme activity in the adrenal cortex. The physiological significance of these phenomena, however, remains unknown. Plasma ACTH and corticosterone levels were determined by radioimmunoassay (RIA) of systemic blood samples and NOS enzyme activity was measured as the rate of [3H]arginine conversion to [3H]citrulline in the presence of tissue homogenate of adrenal cortex separated from the adrenal gland. The NOS enzyme activity in the adrenal cortex of rats pre-injected with saline at 2 h after the 2-h immobilization was significantly higher (P < 0.01) than that in the non-stressed controls. Pre-injection of L-NAME (100 mg/kg, s.c.) almost completely abolished the activity. This dose of L-NAME maintained a significantly elevated plasma corticosterone level (P < 0.05, compared with basal level) even 2 h after the 2-h stress, whereas the plasma corticosterone level in rats pre-injected with saline returned to the basal level at the same time point. Plasma ACTH level in L-NAME-pre-treated rats was higher than that in those pre-treated with saline 2 h after the stress, but the difference was not significant. This dose of L-NAME did not influence plasma ACTH or corticosterone levels under resting conditions without stress. These findings suggest that the stress-induced increase in NO synthesis in the adrenal cortex can modify the stress-induced corticosterone response to facilitate the recovery from the elevated corticosterone secretion by stress in the adrenal cortex to the resting basal level.
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Affiliation(s)
- T Tsuchiya
- Life Science Research Laboratories, Shiseido Research Center, Yokohama, Japan
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