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Bagues A, Lopez-Tofiño Y, Galvez-Robleño C, Abalo R. Effects of two different acute and subchronic stressors on gastrointestinal transit in the rat: A radiographic analysis. Neurogastroenterol Motil 2021; 33:e14232. [PMID: 34378822 DOI: 10.1111/nmo.14232] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/08/2021] [Accepted: 07/13/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND The reaction to stress is an adaptive response necessary for survival. When stressors are repeated, the organism adapts, although these adaptive responses can become dysregulated and result in disease, causing gastrointestinal (GI) disorders. Radiographic methods allow the non-invasive study of how a given factor affects GI transit in the same animal at different time points. These methods have never been applied to study the consequences of stress on GI motor function and their dependency on time and stimulus. Therefore, our aim was to characterize, using radiographic techniques, the effect on GI transit of cold-restraint (CR) and forced swim (FS) stress applied acutely and subchronically in the rat. METHODS Male Wistar rats (260-330 g) were submitted to FS or CR stress, during 1 (acute) or 4 (subchronic) consecutive days. To study GI transit, radiographic methods were used. Radiographs were taken 0-24 h after barium intragastric administration on the 1st or 4th day of stress, which was applied 1 h after contrast. RESULTS Acute FS or CR slowed down gastric and small intestinal emptying but had opposite effects in the caecum: CR tended to accelerate barium transit and feces formation while FS tended to slow these parameters down. When the stimuli were applied subchronically, GI transit was not completely normalized in most of the studied parameters. CONCLUSION AND INFERENCES Mild stress alters GI transit differently depending on the nature of the stressor and its duration. Exposure to mild stressors should be considered as contributing factors to different functional GI disorders.
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Affiliation(s)
- Ana Bagues
- Department of Basic Health Sciences, Universidad Rey Juan Carlos (URJC, Alcorcón, Spain
- High Performance Research Group in Experimental Pharmacology (PHARMAKOM-URJC, URJC, Alcorcón, Spain
- Unidad, Instituto de Química Médica (IQM, Consejo Superior de Investigaciones Científicas (CSIC, Asociada I+D+i del, Madrid, Spain
| | - Yolanda Lopez-Tofiño
- Department of Basic Health Sciences, Universidad Rey Juan Carlos (URJC, Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut-URJC, URJC, Alcorcón, Spain
| | - Carlos Galvez-Robleño
- Department of Basic Health Sciences, Universidad Rey Juan Carlos (URJC, Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut-URJC, URJC, Alcorcón, Spain
| | - Raquel Abalo
- Department of Basic Health Sciences, Universidad Rey Juan Carlos (URJC, Alcorcón, Spain
- Unidad, Instituto de Química Médica (IQM, Consejo Superior de Investigaciones Científicas (CSIC, Asociada I+D+i del, Madrid, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut-URJC, URJC, Alcorcón, Spain
- Grupo de Trabajo de Ciencias Básicas en Dolor y Analgesia de la Sociedad Española del Dolor, Madrid, Spain
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Faykoo-Martinez M, Kalinowski LM, Holmes MM. Neuroendocrine regulation of pubertal suppression in the naked mole-rat: What we know and what comes next. Mol Cell Endocrinol 2021; 534:111360. [PMID: 34116130 DOI: 10.1016/j.mce.2021.111360] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/20/2021] [Accepted: 06/03/2021] [Indexed: 01/13/2023]
Abstract
Puberty is a key developmental milestone that marks an individual's maturation in several ways including, but not limited to, reproductive maturation, changes in behaviors and neural organization. The timing at which puberty occurs is variable both within individuals of the same species and between species. These variations can be aligned with ecological cues that delay or suppress puberty. Naked mole-rats are colony-living rodents where reproduction is restricted to a few animals; all other animals are pubertally-suppressed. Animals removed from suppressive colony cues can reproductively mature, presenting the unique opportunity to study adult-onset puberty. Recently, we found that RFRP-3 administration sustains pubertal delay in naked mole-rats removed from colony. In this review, we explore what is known about regulators that control puberty onset, the role of stress/social status in pubertal timing, the status of knowledge of pubertal suppression in naked mole-rats and what comes next.
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Affiliation(s)
| | | | - Melissa M Holmes
- Department of Cell and Systems Biology, University of Toronto, Canada; Department of Psychology, University of Toronto Mississauga, Canada; Department of Ecology and Evolutionary Biology, University of Toronto, Canada
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Kozakai Y, Hori K, Aye-Mon A, Okuda H, Harada SI, Hayashi K, Ozaki N. The role of peripheral corticotropin-releasing factor signaling in a rat model of stress-induced gastric hyperalgesia. Biochem Biophys Res Commun 2019; 519:797-802. [PMID: 31558322 DOI: 10.1016/j.bbrc.2019.09.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 09/11/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Functional dyspepsia (FD) is a common gastrointestinal disorder associated with persistent or recurrent upper gastrointestinal tract symptoms such as pain without any obvious pathological changes. Psychological and psychiatric factors might have a pathogenic role in FD. Changes in the sensation of stomach pain were determined after application of stress to adult rats. The involvement of corticotropin-releasing factor (CRF), Type 2 CRF receptor (CRF2) and inflammatory cytokine interleukin-6 (IL-6) was also investigated in the gastric hyperalgesia observed in this model. RESULTS Repeated water avoidance stress (WA-S) produced gastric hyperalgesia, with no obvious lesions in the gastric mucosa. Gastric hyperalgesia was inhibited by CRF and CRF2 antagonists, suggesting their involvement in gastric hyperalgesia observed after application of stress. Gastric hyperalgesia was inhibited by IL-6 neutralizing antibody. Immunofluorescence staining demonstrated CRF, CRF2, urocortin (Ucn)1, and Ucn2-positive cells in the gastric mucosa. CRF2-positive cells increased after WA-S, compared to sham stress. CRF2 and Ucn2 were expressed in the mast cells in the gastric mucosa. CONCLUSIONS CRF2 plays an important role in gastric hyperalgesia produced by stress. CRF2 signaling may be a useful therapeutic target for functional dyspepsia.
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Affiliation(s)
- Yu Kozakai
- Department of Functional Anatomy, Graduate School of Medical Sciences, Kanazawa University, Japan
| | - Kiyomi Hori
- Department of Functional Anatomy, Graduate School of Medical Sciences, Kanazawa University, Japan
| | - Aye Aye-Mon
- Department of Anatomy, University of Medicine (1), Yangon, Myanmar
| | - Hiroaki Okuda
- Department of Functional Anatomy, Graduate School of Medical Sciences, Kanazawa University, Japan
| | - Shin-Ichi Harada
- Department of Biochemistry and Center for Biomedical Research and Education, Graduate School of Medical Sciences, Kanazawa University, Japan
| | - Koei Hayashi
- Department of Functional Anatomy, Graduate School of Medical Sciences, Kanazawa University, Japan
| | - Noriyuki Ozaki
- Department of Functional Anatomy, Graduate School of Medical Sciences, Kanazawa University, Japan.
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Bülbül M, Sinen O, Bayramoğlu O, Akkoyunlu G. Acute restraint stress induces cholecystokinin release via enteric apelin. Neuropeptides 2019; 73:71-77. [PMID: 30503693 DOI: 10.1016/j.npep.2018.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/02/2018] [Accepted: 11/26/2018] [Indexed: 12/12/2022]
Abstract
Stress increases the apelin content in gut, while exogenous peripheral apelin has been shown to induce cholecystokinin (CCK) release. The present study was designed to elucidate (i) the effect of acute stress on enteric production of apelin and CCK, (ii) the role of APJ receptors in apelin-induced CCK release depending on the nutritional status. CCK levels were assayed in portal vein blood samples obtained from stressed (ARS) and non-stressed (NS) rats previously injected with APJ receptor antagonist F13A or vehicle. Duodenal expressions of apelin, CCK and APJ receptor were detected by immunohistochemistry. ARS increased the CCK release which was abolished by selective APJ receptor antagonist F13A. The stimulatory effect of ARS on CCK production was only observed in rats fed ad-libitum. Apelin and CCK expressions were upregulated by ARS. In addition to the duodenal I cells, APJ receptor was also detected in CCK-producing myenteric neurons. Enteric apelin appears to regulate the stress-induced changes in GI functions through CCK. Therefore, apelin/APJ receptor systems seem to be a therapeutic target for the treatment of stress-related gastrointestinal disorders.
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Affiliation(s)
- Mehmet Bülbül
- Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey.
| | - Osman Sinen
- Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey
| | - Onur Bayramoğlu
- Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey
| | - Gökhan Akkoyunlu
- Department of Histology and Embryology, Akdeniz University, Faculty of Medicine, Antalya, Turkey
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Schroeder M, Jakovcevski M, Polacheck T, Drori Y, Ben-Dor S, Röh S, Chen A. Sex dependent impact of gestational stress on predisposition to eating disorders and metabolic disease. Mol Metab 2018; 17:1-16. [PMID: 30174229 PMCID: PMC6197785 DOI: 10.1016/j.molmet.2018.08.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/08/2018] [Accepted: 08/14/2018] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE Vulnerability to eating disorders (EDs) is broadly assumed to be associated with early life stress. However, a careful examination of the literature shows that susceptibility to EDs may depend on the type, severity and timing of the stressor and the sex of the individual. We aimed at exploring the link between chronic prenatal stress and predisposition to EDs and metabolic disease. METHODS We used a chronic variable stress protocol during gestation to explore the metabolic response of male and female offspring to food restriction (FR), activity-based anorexia (ABA), binge eating (BE) and exposure to high fat (HF) diet. RESULTS Contrary to controls, prenatally stressed (PNS) female offspring showed resistance to ABA and BE and displayed a lower metabolic rate leading to hyperadiposity and obesity on HF diet. Male PNS offspring showed healthy responses to FR and ABA, increased propensity to binge and improved coping with HF compared to controls. We found that long-lasting abnormal responses to metabolic challenge are linked to fetal programming and adult hypothalamic dysregulation in PNS females, resulting from sexually dimorphic adaptations in placental methylation and gene expression. CONCLUSIONS Our results show that maternal stress may have variable and even opposing effects on ED risk, depending on the ED and the sex of the offspring.
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Affiliation(s)
- Mariana Schroeder
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, 76100, Israel; Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, 80804, Germany.
| | - Mira Jakovcevski
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, 80804, Germany
| | - Tamar Polacheck
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Yonat Drori
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Shifra Ben-Dor
- Bioinformatics and Biological Computing Unit, Biological Services, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Simone Röh
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, 80804, Germany
| | - Alon Chen
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, 76100, Israel; Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, 80804, Germany.
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Qin C, Li J, Tang K. The Paraventricular Nucleus of the Hypothalamus: Development, Function, and Human Diseases. Endocrinology 2018; 159:3458-3472. [PMID: 30052854 DOI: 10.1210/en.2018-00453] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/16/2018] [Indexed: 02/08/2023]
Abstract
The paraventricular nucleus of the hypothalamus (PVH), located in the ventral diencephalon adjacent to the third ventricle, is a highly conserved brain region present in species from zebrafish to humans. The PVH is composed of three main types of neurons, magnocellular, parvocellular, and long-projecting neurons, which play imperative roles in the regulation of energy balance and various endocrinological activities. In this review, we focus mainly on recent findings about the early development of the hypothalamus and the PVH, the functions of the PVH in the modulation of energy homeostasis and in the hypothalamus-pituitary system, and human diseases associated with the PVH, such as obesity, short stature, hypertension, and diabetes insipidus. Thus, the investigations of the PVH will benefit not only understanding of the development of the central nervous system but also the etiology of and therapy for human diseases.
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Affiliation(s)
- Cheng Qin
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, China
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi, China
| | - Jiaheng Li
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, China
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi, China
| | - Ke Tang
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi, China
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, Guangdong, China
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Szűcs K, Grosz G, Süle M, Sztojkov-Ivanov A, Ducza E, Márki A, Kothencz A, Balogh L, Gáspár R. Detection of stress and the effects of central nervous system depressants by gastrointestinal smooth muscle electromyography in wakeful rats. Life Sci 2018; 205:1-8. [DOI: 10.1016/j.lfs.2018.05.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 05/05/2018] [Indexed: 12/22/2022]
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Borrow AP, Bales NJ, Stover SA, Handa RJ. Chronic Variable Stress Induces Sex-Specific Alterations in Social Behavior and Neuropeptide Expression in the Mouse. Endocrinology 2018; 159:2803-2814. [PMID: 29788320 PMCID: PMC6692887 DOI: 10.1210/en.2018-00217] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/10/2018] [Indexed: 12/11/2022]
Abstract
Chronic exposure to stressors impairs the function of multiple organ systems and has been implicated in increased disease risk. In the rodent, the chronic variable stress (CVS) paradigm has successfully modeled several stress-related illnesses. Despite striking disparities between men and women in the prevalence and etiology of disorders associated with chronic stress, most preclinical research examining chronic stressor exposure has focused on male subjects. One potential mediator of the consequences of CVS is oxytocin (OT), a known regulator of stress neurocircuitry and behavior. To ascertain the sex-specific effects of CVS in the C57BL/6 mouse on OT and the structurally similar neuropeptide arginine vasopressin (AVP), the numbers of immunoreactive and mRNA-containing neurons in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) were determined using immunohistochemistry and in situ hybridization, respectively. In addition, the mice underwent a battery of behavioral tests to determine whether CVS affects social behaviors known to be regulated by OT and AVP. Six weeks of CVS increased sociability in the female mouse and decreased PVN OT immunoreactivity (ir) and AVP mRNA. In the male mice, CVS decreased PVN OT mRNA but had no effect on social behavior, AVP, or OT-ir. CVS also increased the soma volume for PVN OT neurons. In contrast, OT and AVP neurons in the SON were unaffected by CVS treatment. These findings demonstrate clear sex differences in the effects of CVS on neuropeptides in the mouse, suggest a pathway through which CVS alters sociability and stress-coping responses in females and reveals a vulnerability to CVS in the C57BL/6 mouse strain.
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Affiliation(s)
- Amanda P Borrow
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Natalie J Bales
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Sally A Stover
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Robert J Handa
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
- Correspondence: Robert J. Handa, PhD, Department of Biomedical Sciences, Colorado State University, 1617 Campus Delivery, Fort Collins, Colorado 80523. E-mail:
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Bülbül M, Travagli RA. Novel transmitters in brain stem vagal neurocircuitry: new players on the pitch. Am J Physiol Gastrointest Liver Physiol 2018; 315:G20-G26. [PMID: 29597355 PMCID: PMC6109706 DOI: 10.1152/ajpgi.00059.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The last few decades have seen a major increase in the number of neurotransmitters and neuropeptides recognized as playing a role in brain stem neurocircuits, including those involved in homeostatic functions such as stress responsiveness, gastrointestinal motility, feeding, and/or arousal/wakefulness. This minireview will focus on the known physiological role of three of these novel neuropeptides, i.e., apelin, nesfatin-1, and neuropeptide-S, with a special emphasis on their hypothetical roles in vagal signaling related to gastrointestinal motor functions.
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Affiliation(s)
- Mehmet Bülbül
- 1Faculty of Medicine, Department of Physiology, Akdeniz UniversityAntalya, Turkey
| | - R. Alberto Travagli
- 2Department of Neural and Behavioral Neurosciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
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Żera T, Przybylski J, Grygorowicz T, Kasarełło K, Podobińska M, Mirowska-Guzel D, Cudnoch-Jędrzejewska A. Vasopressin V1a receptors are present in the carotid body and contribute to the control of breathing in male Sprague-Dawley rats. Peptides 2018. [PMID: 29524562 DOI: 10.1016/j.peptides.2018.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Vasopressin (AVP) maintains body homeostasis by regulating water balance, cardiovascular system and stress response. AVP inhibits breathing through central vasopressin 1a receptors (V1aRs). Chemoreceptors within carotid bodies (CBs) detect chemical and hormonal signals in the bloodstream and provide sensory input to respiratory and cardiovascular centers of the brainstem. In the study we investigated if CBs contain V1aRs and how the receptors are involved in the regulation of ventilation by AVP. We first immunostained CBs for V1aRs and tyrosine hydroxylase, a marker of chemoreceptor type I (glomus) cells. In urethane-anesthetized adult Sprague-Dawley male rats, we then measured hemodynamic and respiratory responses to systemic (intravenous) or local (carotid artery) administration of AVP prior and after systemic blockade of V1aRs. Immunostaining of CBs showed colocalization of V1aRs and tyrosine hydroxylase within glomus cells. Systemic administration of AVP increased mean arterial blood pressure (MABP) and decreased respiratory rate (RR) and minute ventilation (MV). Local administration of AVP increased MV and RR without significant changes in MABP or heart rate. Pretreatment with V1aR antagonist abolished responses to local and intravenous AVP administration. Our findings show that chemosensory cells within CBs express V1aRs and that local stimulation of the CB with AVP increases ventilation, which is contrary to systemic effects of AVP manifested by decreased ventilation. The responses are mediated by V1aRs, as blockade of the receptors prevents changes in ventilation. We hypothesize that excitatory effects of AVP within the CB provide a counterbalancing mechanism for the inhibitory effects of systemically acting AVP on the respiration.
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Affiliation(s)
- Tymoteusz Żera
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, the Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland.
| | - Jacek Przybylski
- Department of Biophysics and Physiology, the Medical University of Warsaw, Chałubińskiego 5, 02-004 Warsaw, Poland
| | - Tomasz Grygorowicz
- Chair and Department of Experimental and Clinical Pharmacology, Laboratory of Centre for Preclinical Research, the Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
| | - Kaja Kasarełło
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, the Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
| | - Martyna Podobińska
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, the Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
| | - Dagmara Mirowska-Guzel
- Chair and Department of Experimental and Clinical Pharmacology, Laboratory of Centre for Preclinical Research, the Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
| | - Agnieszka Cudnoch-Jędrzejewska
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, the Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
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Gong Y, Liu Y, Liu F, Wang S, Jin H, Guo F, Xu L. Ghrelin fibers from lateral hypothalamus project to nucleus tractus solitaries and are involved in gastric motility regulation in cisplatin-treated rats. Brain Res 2017; 1659:29-40. [PMID: 28093190 DOI: 10.1016/j.brainres.2017.01.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 12/28/2016] [Accepted: 01/01/2017] [Indexed: 12/16/2022]
Abstract
Ghrelin can alleviate cancer chemotherapy-induced dyspepsia in rodents, though the neural mechanisms involved are not known. Therefore, ghrelin projections from the lateral hypothalamus (LH) and its involvement in the regulation of gastric motility in cisplatin-treated rats were investigated with a multi-disciplined approach. Retrograde tracing combined with fluoro-immunohistochemical staining were used to investigate ghrelin fiber projections arising from LH and projecting to nucleus tractus solitaries (NTS). Results revealed that ghrelin fibers originating in LH project to NTS. Expression of ghrelin and its receptor growth hormone secretagogue receptor (GHS-R1a) in LH and NTS were detected by Western Blot. 2days after cisplatin dosing, expression of ghrelin in LH decreased while GHS-R1a in both LH and NTS increased. In electrophysiological experiments, the effects of N-methyl-d-aspartate (NMDA) microinjection in LH on neuronal discharge of gastric distension-responsive neurons in NTS and gastric motility were assessed. NMDA in LH excited most of ghrelin-responsive gastric distension (GD)-sensitive neurons in NTS and promoted gastric motility. This effect was partially blocked by ghrelin antibody in NTS. Furthermore, the excitatory effects of NMDA in cisplatin-treated rats were weaker than those in saline-treated rats. Behaviorally, cisplatin induced a significant increase of kaolin consumption and decrease of food intake. These studies reveal a decreased expression of ghrelin in LH and up-regulation of GHS-R1a in LH and NTS, which are involved in the regulation of GD neuronal discharge in NTS and gastric motility.
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Affiliation(s)
- Yanling Gong
- Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, Shandong, China.
| | - Yang Liu
- Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, Shandong, China
| | - Fei Liu
- Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, Shandong, China
| | - Shasha Wang
- Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, Shandong, China
| | - Hong Jin
- Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, Shandong, China
| | - Feifei Guo
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, Shandong, China
| | - Luo Xu
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, Shandong, China.
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