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Larauche M, Kim YS, Mulak A, Duboc H, Taché Y. Intracerebroventricular administration of TRH Agonist, RX-77368 alleviates visceral pain induced by colorectal distension in rats. Peptides 2024; 175:171181. [PMID: 38423212 DOI: 10.1016/j.peptides.2024.171181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 01/18/2024] [Accepted: 02/26/2024] [Indexed: 03/02/2024]
Abstract
Thyrotropin-releasing hormone (TRH) acts centrally to exert pleiotropic actions independently from its endocrine function, including antinociceptive effects against somatic pain in rodents. Whether exogenous or endogenous activation of TRH signaling in the brain modulates visceral pain is unknown. Adult male Sprague-Dawley rats received an intracerebroventricular (ICV) injection of the stable TRH analog, RX-77368 (10, 30 and 100 ng/rat) or saline (5 µl) or were semi-restrained and exposed to cold (4°C) for 45 min. The visceromotor response (VMR) to graded phasic colorectal distensions (CRD) was monitored using non-invasive intracolonic pressure manometry. Naloxone (1 mg/kg) was injected subcutaneously 10 min before ICV RX-77368 or saline. Fecal pellet output was monitored for 1 h after ICV injection. RX-77368 ICV (10, 30 and 100 ng/rat) reduced significantly the VMR by 56.7%, 67.1% and 81.1% at 40 mmHg and by 30.3%, 58.9% and 87.4% at 60 mmHg respectively vs ICV saline. Naloxone reduced RX-77368 (30 and 100 ng, ICV) analgesic response by 51% and 28% at 40 mmHg and by 30% and 33% at 60 mmHg respectively, but had no effect per se. The visceral analgesia was mimicked by the acute exposure to cold. At the doses of 30 and 100 ng, ICV RX-77368 induced defecation within 30 min. These data established the antinociceptive action of RX-77368 injected ICV in a model of visceral pain induced by colonic distension through recruitment of both opioid and non-opioid dependent mechanisms.
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Affiliation(s)
- Muriel Larauche
- Digestive Diseases Research Center and G. Oppenheimer Center for Neurobiology of Stress and Resilience, Department of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, University of California Los Angeles, and VA Greater Los Angeles Healthcare System, CA 90073, USA.
| | - Yong Sung Kim
- Digestive Diseases Research Center and G. Oppenheimer Center for Neurobiology of Stress and Resilience, Department of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, University of California Los Angeles, and VA Greater Los Angeles Healthcare System, CA 90073, USA
| | - Agata Mulak
- Digestive Diseases Research Center and G. Oppenheimer Center for Neurobiology of Stress and Resilience, Department of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, University of California Los Angeles, and VA Greater Los Angeles Healthcare System, CA 90073, USA
| | - Henri Duboc
- Digestive Diseases Research Center and G. Oppenheimer Center for Neurobiology of Stress and Resilience, Department of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, University of California Los Angeles, and VA Greater Los Angeles Healthcare System, CA 90073, USA
| | - Yvette Taché
- Digestive Diseases Research Center and G. Oppenheimer Center for Neurobiology of Stress and Resilience, Department of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, University of California Los Angeles, and VA Greater Los Angeles Healthcare System, CA 90073, USA
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2
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López‐Estévez S, López‐Torrellardona JM, Parera M, Martínez V. Long-lasting visceral hypersensitivity in a model of DSS-induced colitis in rats. Neurogastroenterol Motil 2022; 34:e14441. [PMID: 36239298 PMCID: PMC9787759 DOI: 10.1111/nmo.14441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 05/31/2022] [Accepted: 07/18/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Persistent visceral hypersensitivity is a key component of functional and inflammatory gastrointestinal diseases. Current animal models fail to fully reproduce the characteristics of visceral pain in humans, particularly as it relates to persistent hypersensitivity. This work explores the validity of DSS-induced colitis in rats as a model to mimic chronic intestinal hypersensitivity. METHODS Exposure to DSS (5% for 7 days) was used to induce colitis in rats. Thereafter, changes in viscerosensitivity (visceromotor responses to colorectal distension-CRD), the presence of somatic referred pain (mechanosensitivity of the hind paws, von Frey test) and the expression (qRT-PCR) of sensory-related markers (colon, lumbosacral DRGs, and lumbosacral spinal cord) were assessed at different times during the 35 days period after colitis induction. RESULTS Following colitis, a sustained increase in visceromotor responses to CRD were observed, indicative of the presence of visceral hypersensitivity. Responses in animals without colitis remained stable over time. In colitic animals, somatic referred hypersensitivity was also detected. DSS-induced colitis was associated to a differential expression of sensory-related markers (with both pro- and anti-nociceptive action) in the colon, lumbosacral DRGs and lumbosacral spinal cord; indicating the presence of peripheral and central sensitization. CONCLUSIONS AND INFERENCES DSS-induced colitis in rats is associated to the generation of a long-lasting state of visceral (colonic) hypersensitivity, despite clinical colitis resolution. This model reproduces the changes in intestinal sensitivity characteristics of inflammatory and functional gastrointestinal disorders in humans and can be used in the characterization of new pharmacological treatments against visceral pain.
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Affiliation(s)
- Sergio López‐Estévez
- Department of Cell Biology, Physiology and ImmunologyUniversitat Autònoma de BarcelonaBarcelonaSpain,Neuroscience InstituteUniversitat Autònoma de BarcelonaBarcelonaSpain
| | | | - Marc Parera
- Department of Cell Biology, Physiology and ImmunologyUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Vicente Martínez
- Department of Cell Biology, Physiology and ImmunologyUniversitat Autònoma de BarcelonaBarcelonaSpain,Neuroscience InstituteUniversitat Autònoma de BarcelonaBarcelonaSpain,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd)Instituto de Salud Carlos IIIMadridSpain
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3
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Abstract
The management of pain, particularly chronic pain, is still an area of medical need. In this context, opioids remain a gold standard for the treatment of pain. However, significant side effects, mainly of central origin, limit their clinical use. Here, we review recent progress to improve the therapeutic and safety profiles of opioids for pain management. Characterization of peripheral opioid-mediated pain mechanisms have been a key component of this process. Several studies identified peripheral µ, δ, and κ opioid receptors (MOR, DOR, and KOR, respectively) and nociceptin/orphanin FQ (NOP) receptors as significant players of opioid-mediated antinociception, able to achieve clinically significant effects independently of any central action. Following this, particularly from a medicinal chemistry point of view, main efforts have been directed towards the peripheralization of opioid receptor agonists with the objective of optimizing receptor activity and minimizing central exposure and the associated undesired effects. These activities have allowed the characterization of a great variety of compounds and investigational drugs that show low central nervous system (CNS) penetration (and therefore a reduced side effect profile) yet maintaining the desired opioid-related peripheral antinociceptive activity. These include highly hydrophilic/amphiphilic and massive molecules unable to easily cross lipid membranes, substrates of glycoprotein P (a extrusion pump that avoids CNS penetration), nanocarriers that release the analgesic agent at the site of inflammation and pain, and pH-sensitive opioid agonists that selectively activate at those sites (and represent a new pharmacodynamic paradigm). Hopefully, patients with pain will benefit soon from the incorporation of these new entities.
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4
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Qin HY, Zang KH, Zuo X, Wu XA, Bian ZX. Quercetin Attenuates Visceral Hypersensitivity and 5-Hydroxytryptamine Availability in Postinflammatory Irritable Bowel Syndrome Rats: Role of Enterochromaffin Cells in the Colon. J Med Food 2019; 22:663-671. [PMID: 30920336 DOI: 10.1089/jmf.2018.4264] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Hong-Yan Qin
- Department of Pharmacy, First Hospital of Lanzhou University, Lanzhou, China
| | - Kai-Hong Zang
- College of Pharmacy, Gansu University of Traditional Chinese Medicine, Lanzhou, China
| | - Xiao Zuo
- Department of Pharmacy, First Hospital of Lanzhou University, Lanzhou, China
- School of Pharmaceutical, Lanzhou University, Lanzhou, China
| | - Xin-An Wu
- Department of Pharmacy, First Hospital of Lanzhou University, Lanzhou, China
| | - Zhao-Xiang Bian
- Lab of Brain and Gut Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
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5
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Larauche M, Moussaoui N, Biraud M, Bae W, Duboc H, Million M, Taché Y. Brain corticotropin-releasing factor signaling: Involvement in acute stress-induced visceral analgesia in male rats. Neurogastroenterol Motil 2019; 31:e13489. [PMID: 30298965 PMCID: PMC6347489 DOI: 10.1111/nmo.13489] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND Water avoidance stress (WAS) induces a naloxone-independent visceral analgesia in male rats under non-invasive conditions of monitoring. The objective of the study was to examine the role of brain CRF signaling in acute stress-induced visceral analgesia (SIVA). METHODS Adult male Sprague-Dawley rats were chronically implanted with an intracerebroventricular (ICV) cannula. The visceromotor response (VMR) to graded phasic colorectal distension (CRD: 10, 20, 40, 60 mm Hg, 20 seconds, 4 minutes intervals) was monitored using manometry. The VMR to a first CRD (baseline) was recorded 5 minutes after an ICV saline injection, followed 1 hour later by ICV injection of either CRF (30, 100, or 300 ng and 1, 3, or 5 μg/rat) or saline and a second CRD, 5 minutes later. Receptor antagonists against CRF1 /CRF2 (astressin-B, 30 μg/rat), CRF2 (astressin2 -B, 10 μg/rat), oxytocin (tocinoic acid, 20 μg/rat), or vehicle were injected ICV 5 minutes before CRF (300 ng/rat, ICV) or 15 minutes before WAS (1 hour). KEY RESULTS ICV CRF (100 and 300 ng) reduced the VMR to CRD at 60 mm Hg by -36.6% ± 6.8% and -48.7% ± 11.7%, respectively, vs baseline (P < 0.001), while other doses had no effect and IP CRF (10 µg/kg) induced visceral hyperalgesia. Astressin-B and tocinoic acid injected ICV induced hyperalgesia and prevented the analgesic effect of ICV CRF (300 ng/rat) and WAS, while astressin2 -B only blocked WAS-induced SIVA. CONCLUSIONS & INFERENCES These data support a role for brain CRF signaling via CRF2 in SIVA in a model of WAS and CRD likely mediated by the activation of brain oxytocin pathway.
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Affiliation(s)
- M. Larauche
- Department of Medicine, UCLA, G Oppenheimer Center for
Neurobiology of Stress and Resilience and CURE: Digestive Diseases Research Center,
Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of
Medicine, Los Angeles, CA, United States,VA Greater Los Angeles Healthcare System, Los Angeles, CA,
United States
| | - N. Moussaoui
- Department of Medicine, UCLA, G Oppenheimer Center for
Neurobiology of Stress and Resilience and CURE: Digestive Diseases Research Center,
Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of
Medicine, Los Angeles, CA, United States,VA Greater Los Angeles Healthcare System, Los Angeles, CA,
United States,Present address: Inserm U1048/I2MC Obesity Research
Laboratory, 1 avenue Jean Poulhès BP 84225 31432 Toulouse Cedex 4,
France
| | - M. Biraud
- Department of Medicine, UCLA, G Oppenheimer Center for
Neurobiology of Stress and Resilience and CURE: Digestive Diseases Research Center,
Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of
Medicine, Los Angeles, CA, United States,VA Greater Los Angeles Healthcare System, Los Angeles, CA,
United States,Present address: 1060 William Moore drive CVM Main
Building, RM C305, Raleigh, NC 27607, USA
| | - W.K. Bae
- Department of Medicine, UCLA, G Oppenheimer Center for
Neurobiology of Stress and Resilience and CURE: Digestive Diseases Research Center,
Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of
Medicine, Los Angeles, CA, United States,VA Greater Los Angeles Healthcare System, Los Angeles, CA,
United States,Present address: Department of Internal Medicine, Ilsan
Paik Hospital, Inje University College of Medicine, Goyang, Korea
| | - H. Duboc
- Department of Medicine, UCLA, G Oppenheimer Center for
Neurobiology of Stress and Resilience and CURE: Digestive Diseases Research Center,
Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of
Medicine, Los Angeles, CA, United States,VA Greater Los Angeles Healthcare System, Los Angeles, CA,
United States,Present address: CRI INSERM UMR 1149, University Paris
Diderot, Sorbonne Paris Cité and DHU Unity, APHP, F-75890 Paris, France
| | - M. Million
- Department of Medicine, UCLA, G Oppenheimer Center for
Neurobiology of Stress and Resilience and CURE: Digestive Diseases Research Center,
Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of
Medicine, Los Angeles, CA, United States,VA Greater Los Angeles Healthcare System, Los Angeles, CA,
United States
| | - Y. Taché
- Department of Medicine, UCLA, G Oppenheimer Center for
Neurobiology of Stress and Resilience and CURE: Digestive Diseases Research Center,
Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of
Medicine, Los Angeles, CA, United States,VA Greater Los Angeles Healthcare System, Los Angeles, CA,
United States
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Nissen TD, Brock C, Lykkesfeldt J, Lindström E, Hultin L. Pharmacological modulation of colorectal distension evoked potentials in conscious rats. Neuropharmacology 2018; 140:193-200. [PMID: 30059662 DOI: 10.1016/j.neuropharm.2018.07.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 07/02/2018] [Accepted: 07/24/2018] [Indexed: 12/30/2022]
Abstract
BACKGROUND Cerebral evoked potentials (CEP) induced by colorectal distension (CRD) in conscious rats provides a novel method in studies of visceral sensitivity. The aim of this study was to explore the pharmacological effect on CEP of compounds known to reduce the visceromotor response to CRD. METHODS Epidural electrodes were chronically implanted in eight female Sprague-Dawley rats. Evoked potentials were elicited by colorectal rapid balloon distensions (100 ms, 80 mmHg) and the effect of WIN55 (cannabinoid CB receptor agonist), clonidine (adrenergic α2 receptor agonist), MPEP (mGluR5 receptor antagonist), pregabalin (ligand of α2δ subunits in voltage-gated calcium channels) and baclofen (GABA-B receptor agonist) on amplitudes and latency of CEP were determined. RESULTS WIN55 (0.1 μmol kg-1), clonidine (0.05 μmol kg-1), MPEP (10 μmol kg-1) and pregabalin (200 μmol kg-1) caused a significant, p < 0.05, reduction of the N2 to P2 peak-to-peak amplitude by 23 ± 8%, 25 ± 8%, 39 ± 5%, and 47 ± 6% respectively. Baclofen (9 μmol kg-1) induced a prolongation of the N2 peak latency of 18 ± 4% but had no significant effect on the amplitudes. CONCLUSION The obtained results suggest that MPEP, WIN55, clonidine, and pregabalin reduce visceral nociceptive input to the brain, whereas the lack of effect of baclofen on CRD evoked CEP amplitudes suggest that the effect on VMR is not due to a direct analgesic effect. Brain responses to colorectal distension provide a useful tool to evaluate pharmacological effects in rats and may serve as a valuable preclinical model for understanding pharmacological mechanisms related to visceral sensitivity.
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Affiliation(s)
- Thomas Dahl Nissen
- Laboratory Animal Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden; Mech-Sense, Department of Gastroenterology & Hepatology, Aalborg University Hospital, Aalborg, Denmark; Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christina Brock
- Mech-Sense, Department of Gastroenterology & Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Jens Lykkesfeldt
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Leif Hultin
- Laboratory Animal Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.
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7
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Shi H, Zhu X, Cui Y, Qin Y, Yang L, Deng X. Analgesic activity of cynaropicrinon on post-inflammatory irritable bowel syndrome visceral hypersensitivity in a rat model. Exp Ther Med 2017; 14:4476-4482. [PMID: 29067122 DOI: 10.3892/etm.2017.5037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 08/10/2017] [Indexed: 11/05/2022] Open
Abstract
Visceral hypersensitivity is one of the most common symptoms in patients with post-inflammatory-irritable bowel syndrome (PI-IBS). Enterochromaffin (EC) cells and 5-hydroxytryptamine (5-HT) are important in the development of visceral hyperalgesia, and EC cells are influenced by helper T-cell subtype 1 or 2 cytokine predominant environments. In the present study, the analgesic effect of cynaropicrin and its underlying mechanism on the treatment of trinitrobenzene sulfonic (TNBS)-induced PI-IBS visceral hyperalgesia rats was investigated. The results from the abdominal withdrawal reflex tests and electromyography recordings indicated that treatment with cynaropicrin significantly and dose-dependently alleviated the visceral hyperalgesia of PI-IBS rats (P<0.05). In addition, the increased colonic 5-HT content, colonic tryptophan hydroxylase expression, EC cell number and the cytokine levels, including tumor necrosis factor-α and interleukin-6 in PI-IBS rats were significantly alleviated by cynaropicrin (P<0.05). These data demonstrate that the analgesic activity of cynaropicrin on TNBS-induced PI-IBS visceral hypersensitive rats was mediated via reduction of cytokines levels. Thus, cynaropicrin as a bioactive natural product may offer promising therapeutic avenues for visceral hypersensitivity in IBS.
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Affiliation(s)
- Hailong Shi
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an Shaanxi 710069, P.R. China.,College of Basic Medicine, Shaanxi University of Chinese Medicine, Xi'an-Xianyang New Economic Zone, Xianyang Shaanxi 712046, P.R. China
| | - Xianwei Zhu
- College of Basic Medicine, Shaanxi University of Chinese Medicine, Xi'an-Xianyang New Economic Zone, Xianyang Shaanxi 712046, P.R. China.,Innovation Research Centre of Acupuncture Combined with Medicine, Shaanxi University of Chinese Medicine, Xi'an-Xianyang New Economic Zone, Shaanxi 712046, P.R. China.,Graduate School of Innovative Life Science for Education, University of Toyama, Toyama 930-8555, Japan
| | - Yaya Cui
- College of Basic Medicine, Shaanxi University of Chinese Medicine, Xi'an-Xianyang New Economic Zone, Xianyang Shaanxi 712046, P.R. China
| | - Yifei Qin
- The Second Clinical Medical College, Shaanxi University of Chinese Medicine, Xi'an-Xianyang New Economic Zone, Xianyang Shaanxi 712046, P.R. China
| | - Lin Yang
- Graduate School of Innovative Life Science for Education, University of Toyama, Toyama 930-8555, Japan
| | - Xu Deng
- College of Basic Medicine, Shaanxi University of Chinese Medicine, Xi'an-Xianyang New Economic Zone, Xianyang Shaanxi 712046, P.R. China
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8
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Shi H, Cui Y, Qin Y. Discovery and characterization of a novel tryptophan hydroxylase 1 inhibitor as a prodrug. Chem Biol Drug Des 2017; 91:202-212. [DOI: 10.1111/cbdd.13071] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 05/31/2017] [Accepted: 06/24/2017] [Indexed: 01/05/2023]
Affiliation(s)
- Hailong Shi
- Laboratory for Functional Glycomics; College of Life Sciences; Northwest University; Xi'an City Shaanxi Province China
- College of Basic Medicine; Shaanxi University of Chinese Medicine; Xi'an-Xianyang New Economic Zone; Xianyang City Shaanxi Province China
| | - Yaya Cui
- College of Basic Medicine; Shaanxi University of Chinese Medicine; Xi'an-Xianyang New Economic Zone; Xianyang City Shaanxi Province China
| | - Yifei Qin
- The Second Clinical Medical College; Shaanxi University of Chinese Medicine; Xi'an-Xianyang New Economic Zone; Xianyang City Shaanxi Province China
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9
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Moloney RD, Sajjad J, Foley T, Felice VD, Dinan TG, Cryan JF, O'Mahony SM. Estrous cycle influences excitatory amino acid transport and visceral pain sensitivity in the rat: effects of early-life stress. Biol Sex Differ 2016; 7:33. [PMID: 27429736 PMCID: PMC4946195 DOI: 10.1186/s13293-016-0086-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/01/2016] [Indexed: 01/26/2023] Open
Abstract
Background Early-life stress (ELS) is a recognized risk factor for chronic pain disorders, and females appear to be more sensitive to the negative effects of stress. Moreover, estrous cycle-related fluctuations in estrogen levels have been linked with alternating pain sensitivity. Aberrant central circuitry involving both the anterior cingulate cortex (ACC) and the lumbosacral spinal cord has also been implicated in the modulation of visceral pain in clinical and preclinical studies. Here we further investigate changes in visceral pain sensitivity and central glutamatergic systems in rats with respect to estrous cycle and ELS. Methods We investigated visceral sensitivity in adult female Sprague-Dawley rats, which had undergone maternal separation (MS) in early life or remained non-separated (NS), by performing colorectal distension (CRD). We also assessed excitatory amino acid uptake through excitatory amino acid transporters (EAATs) in the lumbosacral spinal cord and ACC. Results NS animals in proestrus and estrus exhibited reduced EAAT uptake and decreased threshold to CRD. Moreover, total pain behaviors were increased in these stages. MS rats exhibited lower pain thresholds and higher total pain behaviors to CRD across all stages of the estrous cycle. Interestingly, cortical EAAT function in MS rats was inhibited in the low estrogen state—an effect completely opposite to that seen in NS rats. Conclusions This data confirms that estrous cycle and ELS are significant factors in visceral sensitivity and fluctuations in EAAT function may be a perpetuating factor mediating central sensitization.
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Affiliation(s)
- Rachel D Moloney
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland.,Present Address: Oklahoma Center for Neuroscience, University of Oklahoma Health Science Center, Oklahoma City, OK USA
| | - Jahangir Sajjad
- Department of Anatomy and Neuroscience, University College Cork, Office 4.113, Western Gateway Building, Cork, Ireland
| | - Tara Foley
- Department of Anatomy and Neuroscience, University College Cork, Office 4.113, Western Gateway Building, Cork, Ireland
| | - Valeria D Felice
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Timothy G Dinan
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - John F Cryan
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Office 4.113, Western Gateway Building, Cork, Ireland
| | - Siobhain M O'Mahony
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Office 4.113, Western Gateway Building, Cork, Ireland
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10
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Tramullas M, Finger BC, Dinan TG, Cryan JF. Obesity Takes Its Toll on Visceral Pain: High-Fat Diet Induces Toll-Like Receptor 4-Dependent Visceral Hypersensitivity. PLoS One 2016; 11:e0155367. [PMID: 27159520 PMCID: PMC4861320 DOI: 10.1371/journal.pone.0155367] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 04/27/2016] [Indexed: 12/30/2022] Open
Abstract
Exposure to high-fat diet induces both, peripheral and central alterations in TLR4 expression. Moreover, functional TLR4 is required for the development of high-fat diet-induced obesity. Recently, central alterations in TLR4 expression have been associated with the modulation of visceral pain. However, it remains unknown whether there is a functional interaction between the role of TLR4 in diet-induced obesity and in visceral pain. In the present study we investigated the impact of long-term exposure to high-fat diet on visceral pain perception and on the levels of TLR4 and Cd11b (a microglial cell marker) protein expression in the prefrontal cortex (PFC) and hippocampus. Peripheral alterations in TLR4 were assessed following the stimulation of spleenocytes with the TLR4-agonist LPS. Finally, we evaluated the effect of blocking TLR4 on visceral nociception, by administering TAK-242, a selective TLR4-antagonist. Our results demonstrated that exposure to high-fat diet induced visceral hypersensitivity. In parallel, enhanced TLR4 expression and microglia activation were found in brain areas related to visceral pain, the PFC and the hippocampus. Likewise, peripheral TLR4 activity was increased following long-term exposure to high-fat diet, resulting in an increased level of pro-inflammatory cytokines. Finally, TLR4 blockage counteracted the hyperalgesic phenotype present in mice fed on high-fat diet. Our data reveal a role for TLR4 in visceral pain modulation in a model of diet-induced obesity, and point to TLR4 as a potential therapeutic target for the development of drugs to treat visceral hypersensitivity present in pathologies associated to fat diet consumption.
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Affiliation(s)
- Mónica Tramullas
- APC Microbiome Institute, University College Cork, Cork, Ireland
- * E-mail:
| | | | - Timothy G. Dinan
- APC Microbiome Institute, University College Cork, Cork, Ireland
- Department of Psychiatry & Neurobehavioural Science, University College Cork, Cork, Ireland
| | - John F. Cryan
- APC Microbiome Institute, University College Cork, Cork, Ireland
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland
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11
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Deiteren A, De Man JG, Keating C, Jiang W, De Schepper HU, Pelckmans PA, Francque SM, De Winter BY. Mechanisms contributing to visceral hypersensitivity: focus on splanchnic afferent nerve signaling. Neurogastroenterol Motil 2015; 27:1709-20. [PMID: 26337498 DOI: 10.1111/nmo.12667] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 08/04/2015] [Indexed: 12/24/2022]
Abstract
BACKGROUND Visceral hypersensitivity is a main characteristic of functional bowel disorders and is mediated by both peripheral and central factors. We investigated whether enhanced splanchnic afferent signaling in vitro is associated with visceral hypersensitivity in vivo in an acute and postinflammatory rat model of colitis. METHODS Trinitrobenzene sulfonic acid (TNBS)-colitis was monitored individually by colonoscopy to confirm colitis and follow convalescence and endoscopic healing in each rat. Experiments were performed in controls, rats with acute colitis and in postcolitis rats. Colonic afferent mechanosensitivity was assessed in vivo by quantifying visceromotor responses (VMRs), and by making extracellular afferent recordings from splanchnic nerve bundles in vitro. Multiunit afferent activity was classified into single units identified as low threshold (LT), wide dynamic range (WDR), high threshold (HT), and mechanically insensitive afferents (MIA). KEY RESULTS During acute TNBS-colitis, VMRs were significantly increased and splanchnic nerve recordings showed proportionally less MIA and increased WDR and HT afferents. Acute colitis gave rise to an enhanced spontaneous activity of both LT and MIA and augmented afferent mechanosensitivity in LT, WDR and HT afferents. Postcolitis, VMRs remained significantly increased, whereas splanchnic nerve recordings showed that the proportion of LT, WDR, HT and MIA had normalized to control values. However, LT and MIA continued to show increased spontaneous activity and WDR and HT remained sensitized to colorectal distension. CONCLUSIONS & INFERENCES Visceral hypersensitivity in vivo is associated with sensitized splanchnic afferent responses both during acute colitis and in the postinflammatory phase. However, splanchnic afferent subpopulations are affected differentially at both time points.
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Affiliation(s)
- A Deiteren
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
| | - J G De Man
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
| | - C Keating
- Department of Biomedical Sciences, University of Sheffield, Sheffield, UK
| | - W Jiang
- Department of Biomedical Sciences, University of Sheffield, Sheffield, UK
| | - H U De Schepper
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
- Department of Gastroenterology and Hepatology, Antwerp University Hospital, Antwerp, Belgium
| | - P A Pelckmans
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
- Department of Gastroenterology and Hepatology, Antwerp University Hospital, Antwerp, Belgium
| | - S M Francque
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
- Department of Gastroenterology and Hepatology, Antwerp University Hospital, Antwerp, Belgium
| | - B Y De Winter
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
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Moloney RD, O'Mahony SM, Dinan TG, Cryan JF. Stress-induced visceral pain: toward animal models of irritable-bowel syndrome and associated comorbidities. Front Psychiatry 2015; 6:15. [PMID: 25762939 PMCID: PMC4329736 DOI: 10.3389/fpsyt.2015.00015] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 01/28/2015] [Indexed: 12/12/2022] Open
Abstract
Visceral pain is a global term used to describe pain originating from the internal organs, which is distinct from somatic pain. It is a hallmark of functional gastrointestinal disorders such as irritable-bowel syndrome (IBS). Currently, the treatment strategies targeting visceral pain are unsatisfactory, with development of novel therapeutics hindered by a lack of detailed knowledge of the underlying mechanisms. Stress has long been implicated in the pathophysiology of visceral pain in both preclinical and clinical studies. Here, we discuss the complex etiology of visceral pain reviewing our current understanding in the context of the role of stress, gender, gut microbiota alterations, and immune functioning. Furthermore, we review the role of glutamate, GABA, and epigenetic mechanisms as possible therapeutic strategies for the treatment of visceral pain for which there is an unmet medical need. Moreover, we discuss the most widely described rodent models used to model visceral pain in the preclinical setting. The theory behind, and application of, animal models is key for both the understanding of underlying mechanisms and design of future therapeutic interventions. Taken together, it is apparent that stress-induced visceral pain and its psychiatric comorbidities, as typified by IBS, has a multifaceted etiology. Moreover, treatment strategies still lag far behind when compared to other pain modalities. The development of novel, effective, and specific therapeutics for the treatment of visceral pain has never been more pertinent.
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Affiliation(s)
- Rachel D Moloney
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork , Cork , Ireland
| | - Siobhain M O'Mahony
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork , Cork , Ireland ; Department of Anatomy and Neuroscience, University College Cork , Cork , Ireland
| | - Timothy G Dinan
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork , Cork , Ireland ; Department of Psychiatry, University College Cork , Cork , Ireland
| | - John F Cryan
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork , Cork , Ireland ; Department of Anatomy and Neuroscience, University College Cork , Cork , Ireland
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Wade PR, Palmer JM, McKenney S, Kenigs V, Chevalier K, Moore BA, Mabus JR, Saunders PR, Wallace NH, Schneider CR, Kimball ES, Breslin HJ, He W, Hornby PJ. Modulation of gastrointestinal function by MuDelta, a mixed µ opioid receptor agonist/ µ opioid receptor antagonist. Br J Pharmacol 2013; 167:1111-25. [PMID: 22671931 DOI: 10.1111/j.1476-5381.2012.02068.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND & PURPOSE Loperamide is a selective µ opioid receptor agonist acting locally in the gastrointestinal (GI) tract as an effective anti-diarrhoeal but can cause constipation. We tested whether modulating µ opioid receptor agonism with δ opioid receptor antagonism, by combining reference compounds or using a novel compound ('MuDelta'), could normalize GI motility without constipation. EXPERIMENTAL APPROACH MuDelta was characterized in vitro as a potent µ opioid receptor agonist and high-affinity δ opioid receptor antagonist. Reference compounds, MuDelta and loperamide were assessed in the following ex vivo and in vivo experiments: guinea pig intestinal smooth muscle contractility, mouse intestinal epithelial ion transport and upper GI tract transit, entire GI transit or faecal output in novel environment stressed mice, or four weeks after intracolonic mustard oil (post-inflammatory). Colonic δ opioid receptor immunoreactivity was quantified. KEY RESULTS δ Opioid receptor antagonism opposed µ opioid receptor agonist inhibition of intestinal contractility and motility. MuDelta reduced intestinal contractility and inhibited neurogenically-mediated secretion. Very low plasma levels of MuDelta were detected after oral administration. Stress up-regulated δ opioid receptor expression in colonic epithelial cells. In stressed mice, MuDelta normalized GI transit and faecal output to control levels over a wide dose range, whereas loperamide had a narrow dose range. MuDelta and loperamide reduced upper GI transit in the post-inflammatory model. CONCLUSIONS AND IMPLICATIONS MuDelta normalizes, but does not prevent, perturbed GI transit over a wide dose-range in mice. These data support the subsequent assessment of MuDelta in a clinical phase II trial in patients with diarrhoea-predominant irritable bowel syndrome.
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Affiliation(s)
- P R Wade
- Enterology Research Team, Johnson & Johnson Pharmaceutical Research & Development, L.L.C., Spring House, PA 19087, USA
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14
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LARAUCHE M, MULAK A, KIM YS, LABUS J, MILLION M, TACHE Y. Visceral analgesia induced by acute and repeated water avoidance stress in rats: sex difference in opioid involvement. Neurogastroenterol Motil 2012; 24:1031-e547. [PMID: 22776034 PMCID: PMC3470786 DOI: 10.1111/j.1365-2982.2012.01980.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Chronic psychological stress-induced alterations in visceral sensitivity have been predominantly assessed in male rodents. We investigated the effect of acute and repeated water avoidance stress (WAS) on the visceromotor response (VMR) to colorectal distension (CRD) and the role of opioids in male and cycling female Wistar rats using a novel non-invasive manometric technique. METHODS After a baseline VMR (1st CRD, day 0), rats were exposed to WAS (1 h day(-1) ) either once or for four consecutive days, without injection or with naloxone (1 mg kg(-1) ) or saline injected subcutaneously before each WAS session. KEY RESULTS The VMR to CRD recorded on day 1 or 4 immediately after the last WAS was reduced in both females and males. The visceral analgesia was mainly naloxone-dependent in females, but naloxone-independent in males. In non-injected animals, on days 2 and 5, VMR was not significantly different from baseline in males whereas females exhibited a significant VMR increase at 60 mmHg on day 5. Basal CRD and CRD on days 1, 2, and 5 in both sexes without WAS induced similar VMR. CONCLUSIONS & INFERENCES When monitored non-invasively, psychological stress induces an immediate poststress visceral analgesia mediated by an opiate signaling system in females while naloxone-independent in males, and hyperalgesia at 24 h after repeated stress only in females. These data highlight the importance of sex-specific interventions to modulate visceral pain response to stress.
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Affiliation(s)
- Muriel LARAUCHE
- CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Healthcare System CA 90073 USA
| | - Agata MULAK
- CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Healthcare System CA 90073 USA
| | - Yong Sung KIM
- CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Healthcare System CA 90073 USA
| | - Jennifer LABUS
- CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Healthcare System CA 90073 USA
| | - Mulugeta MILLION
- CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Healthcare System CA 90073 USA
| | - Yvette TACHE
- CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Healthcare System CA 90073 USA
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15
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Hultin L, Nissen TD, Kakol-Palm D, Lindström E. Colorectal distension-evoked potentials in awake rats: a novel method for studies of visceral sensitivity. Neurogastroenterol Motil 2012; 24:964-e466. [PMID: 22925114 DOI: 10.1111/nmo.12005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND Quantification of the visceromotor response induced by colorectal distension (CRD) in rodents is commonly used for preclinical studies of visceral pain. The model is well established but does not fully assess the central response to stimulation. The aim of this study was to establish a novel model assessing cerebral evoked potentials (CEPs) in response to CRD in awake rats. METHODS Epidural recording electrodes were chronically implanted in the skull of female Sprague-Dawley rats. Colorectal distension-induced CEPs were recorded using either rapid balloon distensions (100 ms, 20-80 mmHg) or electric stimulation (1 ms, 1-4 mA) using stimulation probes placed in the distal colon. KEY RESULTS Colorectal distension-induced CEPs were separated in three partly temporally overlapping components consisting of five prominent peaks. Peak latencies at 80 mmHg were (P1, N1) 23 ± 1 and 55 ± 4 ms, (N2, P2a, P2b) 91 ± 3, 143 ± 5 and 174 ± 3 ms, and (P3) 297 ± 3 ms. Amplitudes and latencies were, except for the early component, intensity dependent. Intrarectal administration of lidocaine significantly reduced the amplitude of N2 (by 42 ± 6%, P < 0.001) and P2 (by 34 ± 6%, P < 0.001). Electrically induced CEPs were intensity dependent and had similar topography and latencies as the mechanical evoked potentials (P1: 26 ± 2 ms; N1: 61 ± 1 ms; P2: 84 ± 6 ms; N2: 154 ± 6 ms; P3: 326 ± 10 ms), but there were large variations in amplitudes in between repeated electrical stimulations. CONCLUSIONS & INFERENCES Colorectal distension-induced CEPs can be recorded reliably in awake rats and may serve as a surrogate marker of colonic sensation and be a useful parameter in studies of visceral sensitivity.
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Affiliation(s)
- L Hultin
- Integrative Pharmacology, AstraZeneca R&D, Mölndal, Sweden.
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JCM-16021, a Chinese Herbal Formula, Attenuated Visceral Hyperalgesia in TNBS-Induced Postinflammatory Irritable Bowel Syndrome through Reducing Colonic EC Cell Hyperplasia and Serotonin Availability in Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:239638. [PMID: 22719782 PMCID: PMC3376539 DOI: 10.1155/2012/239638] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 03/25/2012] [Accepted: 04/12/2012] [Indexed: 02/06/2023]
Abstract
The present study aimed to investigate the analgesic effect of JCM-16021, a revised traditional Chinese herbal formula, on postinflammatory irritable bowel syndrome (PI-IBS) in rats. The trinitrobenzene sulfonic (TNBS) acid-induced PI-IBS model rats were orally administrated with different doses of JCM-16021 (1.2, 2.4, and 4.8 g/kg/d) for 14 consecutive days. The results showed that JCM-16021 treatment dose-dependently attenuated visceral hyperalgesia in PI-IBS rats. Further, the colonic enterochromaffin (EC) cell number, serotonin (5-HT) content, tryptophan hydroxylase expression, and mechanical-stimuli-induced 5-HT release were significantly ameliorated. Moreover, the decreased levels of mucosal cytokines in PI-IBS, especially the helper T-cell type 1- (T(h)1-) related cytokine TNF-α, were also elevated after JCM-16021 treatment. These data demonstrate that the analgesic effect of JCM-16021 on TNBS-induced PI-IBS rats may be medicated via reducing colonic EC cell hyperplasia and 5-HT availability.
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Abstract
Experimental and clinical evidence has shown that chronic stress plays an important role in the onset and/or exacerbation of symptoms of functional gastrointestinal disorders. Here, we aimed to investigate whether exposure to a chronic and temporally unpredictable psychosocial stressor alters visceral and somatic nociception as well as anxiety-related behaviour. In male C57BL/6J mice, chronic stress was induced by repeated exposure to social defeat (SD, 2 h) and overcrowding (OC, 24 h) during 19 consecutive days. Visceral and somatic nociception was evaluated by colorectal distension and a hot plate, respectively. The social interaction test was used to assess social anxiety. Mice exposed to psychosocial stress developed visceral hyperalgesia and somatic hypoalgesia 24 h following the last stress session. SD/OC mice also exhibited social anxiety-like behaviour. All these changes were also associated with physiological alterations, measured as a decreased faecal pellet output and hypothalamic-pituitary-adrenal (HPA) axis disruption. Taken together, these data confirm that this mouse model of chronic psychosocial stress may be useful for studies on the pathophysiological mechanisms underlying such stress-associated disorders and to further test potential therapies.
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Affiliation(s)
- Mónica Tramullas
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
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18
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Larauche M, Mulak A, Yuan PQ, Kanauchi O, Taché Y. Stress-induced visceral analgesia assessed non-invasively in rats is enhanced by prebiotic diet. World J Gastroenterol 2012; 18:225-36. [PMID: 22294825 PMCID: PMC3261539 DOI: 10.3748/wjg.v18.i3.225] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2011] [Revised: 07/06/2011] [Accepted: 10/27/2011] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the influence of repeated water avoidance stress (rWAS) on the visceromotor response (VMR) to colorectal distension (CRD) and the modulation of the response by a prebiotic diet in rats using a novel surgery-free method of solid-state manometry. METHODS Male Wistar rats fed a standard diet with or without 4% enzyme-treated rice fiber (ERF) for 5 wk were subjected to rWAS (1 h daily x 10 d) or no stress. The VMR to graded phasic CRD was assessed by intraluminal colonic pressure recording on days 0 (baseline), 1 and 10 (45 min) and 11 (24 h) after rWAS and expressed as percentage change from baseline. Cecal content of short chain fatty acids and distal colonic histology were assessed on day 11. RESULTS WAS on day 1 reduced the VMR to CRD at 40 and 60 mmHg similarly by 28.9% ± 6.6% in both diet groups. On day 10, rWAS-induced reduction of VMR occurred only at 40 mmHg in the standard diet group (36.2% ± 17.8%) while in the ERF group VMR was lowered at 20, 40 and 60 mmHg by 64.9% ± 20.9%, 49.3% ± 11.6% and 38.9% ± 7.3% respectively. The visceral analgesia was still observed on day 11 in ERF- but not in standard diet-fed rats. By contrast the non-stressed groups (standard or ERF diet) exhibited no changes in VMR to CRD. In standard diet-fed rats, rWAS induced mild colonic histological changes that were absent in ERF-fed rats exposed to stress compared to non-stressed rats. The reduction of cecal content of isobutyrate and total butyrate, but not butyrate alone, was correlated with lower visceral pain response. Additionally, ERF diet increased rWAS-induced defecation by 26% and 75% during the first 0-15 min and last 15-60 min, respectively, compared to standard diet, and reduced rats' body weight gain by 1.3 fold independently of their stress status. CONCLUSION These data provide the first evidence of psychological stress-related visceral analgesia in rats that was enhanced by chronic intake of ERF prebiotic.
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Larauche M, Mulak A, Taché Y. Stress and visceral pain: from animal models to clinical therapies. Exp Neurol 2012; 233:49-67. [PMID: 21575632 PMCID: PMC3224675 DOI: 10.1016/j.expneurol.2011.04.020] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 04/07/2011] [Accepted: 04/28/2011] [Indexed: 02/07/2023]
Abstract
Epidemiological studies have implicated stress (psychosocial and physical) as a trigger of first onset or exacerbation of irritable bowel syndrome (IBS) symptoms of which visceral pain is an integrant landmark. A number of experimental acute or chronic exteroceptive or interoceptive stressors induce visceral hyperalgesia in rodents although recent evidence also points to stress-related visceral analgesia as established in the somatic pain field. Underlying mechanisms of stress-related visceral hypersensitivity may involve a combination of sensitization of primary afferents, central sensitization in response to input from the viscera and dysregulation of descending pathways that modulate spinal nociceptive transmission or analgesic response. Biochemical coding of stress involves the recruitment of corticotropin releasing factor (CRF) signaling pathways. Experimental studies established that activation of brain and peripheral CRF receptor subtype 1 plays a primary role in the development of stress-related delayed visceral hyperalgesia while subtype 2 activation induces analgesic response. In line with stress pathways playing a role in IBS, non-pharmacologic and pharmacologic treatment modalities aimed at reducing stress perception using a broad range of evidence-based mind-body interventions and centrally-targeted medications to reduce anxiety impact on brain patterns activated by visceral stimuli and dampen visceral pain.
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Affiliation(s)
- Muriel Larauche
- CURE/Digestive Diseases Research Center, Digestive Diseases Division, Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90073, USA.
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20
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Larauche M, Mulak A, Taché Y. Stress-related alterations of visceral sensation: animal models for irritable bowel syndrome study. J Neurogastroenterol Motil 2011; 17:213-34. [PMID: 21860814 PMCID: PMC3155058 DOI: 10.5056/jnm.2011.17.3.213] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 06/12/2011] [Indexed: 12/11/2022] Open
Abstract
Stressors of different psychological, physical or immune origin play a critical role in the pathophysiology of irritable bowel syndrome participating in symptoms onset, clinical presentation as well as treatment outcome. Experimental stress models applying a variety of acute and chronic exteroceptive or interoceptive stressors have been developed to target different periods throughout the lifespan of animals to assess the vulnerability, the trigger and perpetuating factors determining stress influence on visceral sensitivity and interactions within the brain-gut axis. Recent evidence points towards adequate construct and face validity of experimental models developed with respect to animals' age, sex, strain differences and specific methodological aspects such as non-invasive monitoring of visceromotor response to colorectal distension as being essential in successful identification and evaluation of novel therapeutic targets aimed at reducing stress-related alterations in visceral sensitivity. Underlying mechanisms of stress-induced modulation of visceral pain involve a combination of peripheral, spinal and supraspinal sensitization based on the nature of the stressors and dysregulation of descending pathways that modulate nociceptive transmission or stress-related analgesic response.
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Affiliation(s)
- Muriel Larauche
- CURE/Digestive Diseases Research Center and Center for Neurobiology of Stress, Digestive Diseases Division, Department of Medicine, David Geffen School of Medicine, UCLA and VA Greater Los Angeles Healthcare System, Los Angeles, California, USA
| | - Agata Mulak
- CURE/Digestive Diseases Research Center and Center for Neurobiology of Stress, Digestive Diseases Division, Department of Medicine, David Geffen School of Medicine, UCLA and VA Greater Los Angeles Healthcare System, Los Angeles, California, USA
| | - Yvette Taché
- CURE/Digestive Diseases Research Center and Center for Neurobiology of Stress, Digestive Diseases Division, Department of Medicine, David Geffen School of Medicine, UCLA and VA Greater Los Angeles Healthcare System, Los Angeles, California, USA
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Lindström E, Brusberg M, Ravnefjord A, Kakol-Palm D, Påhlman I, Novén A, Larsson H, Martinez V. Oral baclofen reduces visceral pain-related pseudo-affective responses to colorectal distension in rats: relation between plasma exposure and efficacy. Scand J Gastroenterol 2011; 46:652-62. [PMID: 21443414 DOI: 10.3109/00365521.2011.560677] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE We previously showed that activation of GABA(B) receptors by intravenous baclofen reduces pseudo-affective responses to colorectal distension in rats. Here we evaluate the potential clinical significance of these observations. MATERIAL AND METHODS Clinically relevant colorectal distension protocols were used to assess the effects of oral baclofen on visceromotor and autonomic cardiovascular responses in conscious rats. Plasma levels of baclofen were monitored to provide clinical relevance to the doses used. Conscious female Sprague-Dawley rats were subjected to repeated noxious colorectal distension (12 × 80 mmHg), ascending-phasic colorectal distension (10-80 mmHg, 10 mmHg increments) or ramp colorectal distension (10 min ramp at 8 mmHg/min). Visceromotor and cardiovascular responses (mean arterial blood pressure and heart rate) were monitored. Pain-related response thresholds were assessed using ascending-phasic and ramp colorectal distension. RESULTS Baclofen (1-10 μmol/kg, p.o.) reduced the visceromotor response to colorectal distension, reaching a 40% maximal inhibition (p < 0.05). The highest dose (10 μmol/kg, p.o.) also inhibited pain-related cardiovascular responses in telemetrized rats (50-55% reduction in colorectal distension-evoked hypertensive and tachycardic responses; p < 0.05). Similar thresholds for pain-related visceromotor responses were determined during ramp or ascending-phasic colorectal distension (34.1 ± 1.9 and 31.7 ± 3.2 mmHg, respectively). Baclofen (10 μmol/kg, p.o.) increased thresholds to 71.1 ± 3.7 and 77.5 ± 1.8 mmHg during ramp and ascending-phasic colorectal distension, respectively (p < 0.001). Plasma levels of baclofen were 3.3 ± 0.2 μmol/l at 90 min post-dosing, corresponding to the end of the colorectal distension procedure. CONCLUSIONS Oral baclofen, at plasma levels similar to those reported safe and within a therapeutic range in humans, produced significant visceral anti-nociceptive effects in rats.
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22
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Larauche M, Mulak A, Taché Y. Stress and visceral pain: from animal models to clinical therapies. Exp Neurol 2011. [PMID: 21575632 DOI: 10.1016/j.expneurol.2011.04.020.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Epidemiological studies have implicated stress (psychosocial and physical) as a trigger of first onset or exacerbation of irritable bowel syndrome (IBS) symptoms of which visceral pain is an integrant landmark. A number of experimental acute or chronic exteroceptive or interoceptive stressors induce visceral hyperalgesia in rodents although recent evidence also points to stress-related visceral analgesia as established in the somatic pain field. Underlying mechanisms of stress-related visceral hypersensitivity may involve a combination of sensitization of primary afferents, central sensitization in response to input from the viscera and dysregulation of descending pathways that modulate spinal nociceptive transmission or analgesic response. Biochemical coding of stress involves the recruitment of corticotropin releasing factor (CRF) signaling pathways. Experimental studies established that activation of brain and peripheral CRF receptor subtype 1 plays a primary role in the development of stress-related delayed visceral hyperalgesia while subtype 2 activation induces analgesic response. In line with stress pathways playing a role in IBS, non-pharmacologic and pharmacologic treatment modalities aimed at reducing stress perception using a broad range of evidence-based mind-body interventions and centrally-targeted medications to reduce anxiety impact on brain patterns activated by visceral stimuli and dampen visceral pain.
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Affiliation(s)
- Muriel Larauche
- CURE/Digestive Diseases Research Center, Digestive Diseases Division, Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90073, USA.
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23
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Larsson MH, Miketa A, Martinez V. Lack of interaction between psychological stress and DSS-induced colitis affecting colonic sensitivity during colorectal distension in mice. Stress 2009; 12:434-44. [PMID: 19929445 DOI: 10.1080/10253890802626603] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Inflammation and stress have been associated to colorectal hypersensitivity in functional gastrointestinal disorders. We explored if colonic inflammation and stress, alone or combined, participate in the development of visceral hypersensitivity in a mouse model. First, female mice were exposed to 3% dextran sulphate sodium (DSS, 5 days) to induce chronic colitis, followed by repeated psychological stress (water avoidance stress, WAS; 1 h daily/10 days). In a separate experiment, female mice were subjected to WAS and thereafter received 3% DSS. Colitis was evaluated at necropsy. Faecal pellet output served as a marker of stress effect on colonic motility. Visceral pain was assessed at fixed time-points monitoring abdominal contractions during colorectal distension (CRD). DSS provoked a mild chronic colitis that was not affected by previous WAS or aggravated by subsequent stress. WAS induced a significant increase in pellet output, although the response was attenuated in animals with colitis. Responses to CRD were similar in all experimental groups, with transient hyperalgesia observed only during acute colitis. Under the present conditions, neither colitis nor stress, alone or in combination, significantly affected the responses to CRD in mice, suggesting that there is not a direct relationship between inflammation and stress and the development of visceral hypersensitivity.
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Phillis BD, Martin CM, Kang D, Larsson H, Lindström EA, Martinez V, Blackshaw LA. Role of TRPV1 in high-threshold rat colonic splanchnic afferents is revealed by inflammation. Neurosci Lett 2009; 459:57-61. [PMID: 19406204 DOI: 10.1016/j.neulet.2009.04.051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 03/27/2009] [Accepted: 04/23/2009] [Indexed: 01/26/2023]
Abstract
The vanilloid-1 receptor TRPV1 is known to play a role in extrinsic gastrointestinal afferent function. We investigated the role of TRPV1 in mechanosensitivity in afferents from normal and inflamed tissue. Colonic mechanosensitivity was determined in an in vitro rat colon preparation by recording from attached splanchnic nerves. Recordings were made from serosal/mesenteric afferents responding only at high thresholds to graded mechanical stimulation with von Frey probes. Colonic inflammation was induced by adding 5% dextran sulphate sodium (DSS) to the drinking water for 5 days, and was confirmed by histopathology. The selective TRPV1 antagonist, SB-750364 (10(-8) to 10(-6)M), was tested on mechanosensory stimulus response functions of afferents from normal and inflamed preparations (N=7 each). Mechanosensory responses had thresholds of 1-2g, and maximal responses were observed at 12 g. The stimulus response function was not affected by DSS-induced colitis. SB-750364 had no effect on stimulus response functions in normal preparations, but reduced (up to 60%) in a concentration-dependent manner those in inflammation (2-way ANOVA, p<0.05). Moreover, in inflamed tissue, spontaneous afferent activity showed a dose-dependent trend toward reduction with SB-750364. We conclude that mechanosensitivity of high-threshold serosal colonic splanchnic afferents to graded stimuli is unaffected during DSS colitis. However, there is a positive influence of TRPV1 in mechanosensitivity in inflammation, suggesting up-regulation of excitatory TRPV1-mediated mechanisms.
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Affiliation(s)
- Benjamin D Phillis
- Nerve-Gut Research Laboratory, Hanson Institute, Royal Adelaide Hospital, Adelaide, Australia
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25
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Ravnefjord A, Brusberg M, Kang D, Bauer U, Larsson H, Lindström E, Martinez V. Involvement of the transient receptor potential vanilloid 1 (TRPV1) in the development of acute visceral hyperalgesia during colorectal distension in rats. Eur J Pharmacol 2009; 611:85-91. [PMID: 19344705 DOI: 10.1016/j.ejphar.2009.03.058] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Revised: 03/09/2009] [Accepted: 03/23/2009] [Indexed: 01/21/2023]
Abstract
Transient receptor potential vanilloid 1 (TRPV1) channels have been implicated in pain mechanisms and, particularly, in the development of hyperalgesia. We used selective TRPV1 antagonists (NGV-1, SB-750364 and JYL 1421) to assess the role of TRPV1 channels in repetitive noxious colorectal distension (CRD)-induced visceral pain responses in rats. Isobaric CRD (80 mmHg) induced a viscerosomatic response, indicative of visceral pain associated to the distension procedure. Repetition (12 consecutive distensions) of the CRD resulted in an increase in the response over time (119+/-23% increase at distension 12, P<0.05 vs response during the 1st distension) indicative of acute mechanical sensitization. NGV-1 (0.1, 0.3, 1 or 3 micromol/kg, i.v.) prevented in a dose-related manner the development of sensitization, without inducing hypoalgesic responses. SB-750364 (30 micromol/kg, i.v.) had a transitory effect, partially reducing the sensitization response, while JYL 1421 (4.7 micromol/kg, i.v.) was without effect. In the same conditions, the cannabinoid receptor 1 (CB(1)) agonist, WIN55,212-2 (0.1 micromol/kg) reduced pain responses leading to a hypoalgesic state. At 3 micromol/kg, NGV-1, did not affect the pressure-volume relationship during CRD, indicating that TRPV1 channels do not modulate colonic compliance. These observations suggest that TRPV1 channels are involved in the development of acute mechanical colonic hyperalgesia during repetitive noxious CRD in rats. Antagonism of TRPV1 channels might result in antihyperalgesic effects without hypoalgesic activity and might be beneficial in the treatment of visceral pain disorders, such as irritable bowel syndrome. These observations warrant the clinical assessment of TRPV1 antagonists for the treatment of visceral pain.
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CB1 receptors mediate the analgesic effects of cannabinoids on colorectal distension-induced visceral pain in rodents. J Neurosci 2009; 29:1554-64. [PMID: 19193902 DOI: 10.1523/jneurosci.5166-08.2009] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Activation of cannabinoid receptors (CB(1), CB(2) and GPR(55)) produces analgesic effects in several experimental pain models, including visceral pain arising from the gastrointestinal tract. We assessed the role of CB(1), CB(2), and GPR(55) receptors and the endogenous cannabinoid system on basal pain responses and acute mechanical hyperalgesia during colorectal distension (CRD) in rodents. The effects of cannabinoid receptor agonists and antagonists on pain-related responses to CRD were assessed in rats and in wild-type and CB(1) receptor knock-out mice. The dual CB(1/2) agonist, WIN55,212-2, and the peripherally acting CB(1)-selective agonist, SAB-378, inhibited pain-related responses to repetitive noxious CRD (80 mmHg) in a dose-related manner in rats. The analgesic effects of WIN55,212-2 and SAB-378 were blocked by the selective CB(1) antagonist SR141716, but were not affected by the selective CB(2) antagonist SR144528. SR141716, per se, increased the responses to repetitive noxious CRD, indicative of hyperalgesia, and induced pain-related responses during non-noxious CRD (20 mmHg), indicative of allodynia. The cannabinoid receptor agonists anandamide, virodhamine and O-1602 had no effect. At analgesic doses, WIN55,212-2 did not affect colonic compliance. In accordance to the rat data, WIN55,212-2 produced analgesia, whereas SR141716 induced hyperalgesia, during noxious CRD (55 mmHg) in wild-type but not in CB(1)-knock-out mice. These data indicate that peripheral CB(1) receptors mediate the analgesic effects of cannabinoids on visceral pain from the gastrointestinal tract. The allodynic and hyperalgesic responses induced by SR141716 suggest the existence of an endogenous cannabinoid tone and the activation of CB(1) receptors during noxious CRD.
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Bradesi S, Martinez V, Lao L, Larsson H, Mayer EA. Involvement of vasopressin 3 receptors in chronic psychological stress-induced visceral hyperalgesia in rats. Am J Physiol Gastrointest Liver Physiol 2009; 296:G302-9. [PMID: 19033533 DOI: 10.1152/ajpgi.90557.2008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Visceral hypersensitivity and stress have been implicated in the pathophysiology of functional gastrointestinal disorders. We used a selective vasopressin 3 (V(3)) receptor antagonist SSR149415 to investigate the involvement of the vasopressin (AVP)/V(3) signaling system in the development of stress-induced visceral hyperalgesia in rats. Rats were exposed to a daily 1-h session of water avoidance stress (WAS) or sham WAS for 10 consecutive days. The visceromotor response to phasic colorectal distension (CRD, 10-60 mmHg) was assessed before and after stress. Animals were treated daily with SSR149415 (0.3, 1, or 3 mg/kg ip 30 min before each WAS or sham WAS session), with a single dose of SSR149415 (1 mg/kg ip), or the selective corticotropin-releasing factor 1 (CRF(1)) antagonist DMP-696 (30 mg/kg po) before CRD at day 11. Effects of a single dose of SSR149415 (10 mg/kg iv) on acute mechanical sensitization during repetitive CRD (12 distensions at 80 mmHg) were also assessed. In vehicle-treated rats, repeated WAS increased the response to CRD, indicating visceral hypersensitivity. Repeated administration of SSR149415 at 1 or 3 mg/kg completely prevented stress-induced visceral hyperalgesia. Similarly, a single dose of DMP-696 or SSR149415 completely blocked hyperalgesic responses during CRD. In contrast, a single dose of SSR149415 did not affect the acute hyperalgesic responses induced by repeated, noxious distension. These data support a major role for V(3) receptors in repeated psychological stress-induced visceral hyperalgesia and suggest that pharmacological manipulation of the AVP/V(3) pathway might represent an attractive alternative to the CRF/CRF(1) pathway for the treatment of chronic stress-related gastrointestinal disorders.
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Affiliation(s)
- Sylvie Bradesi
- University of California Los Angeles Center for Neurobiology of Stress, Departments of Medicine, Physiology, and Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90073.
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Brusberg M, Ravnefjord A, Martinsson R, Larsson H, Martinez V, Lindström E. The GABAB receptor agonist, baclofen, and the positive allosteric modulator, CGP7930, inhibit visceral pain-related responses to colorectal distension in rats. Neuropharmacology 2009; 56:362-7. [DOI: 10.1016/j.neuropharm.2008.09.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 07/23/2008] [Accepted: 09/09/2008] [Indexed: 10/21/2022]
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Ravnefjord A, Pettersson M, Rehnström E, Martinez V. Acute colonic ischaemia in rats results in long-term structural changes without alterations of colonic sensitivity. Int J Exp Pathol 2008; 89:476-89. [PMID: 19134057 PMCID: PMC2669609 DOI: 10.1111/j.1365-2613.2008.00623.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Accepted: 09/10/2008] [Indexed: 12/19/2022] Open
Abstract
Colonic ischaemia and mast cells have been involved in the pathophysiology of the functional gastrointestinal disorder irritable bowel syndrome, although the cause-effect relationships remain unknown. We assessed long-term histopathological and functional changes associated to an acute ischaemic episode (1 h) of the colon, followed by 8-week recovery, in rats. Functional colonic alterations [sensitivity during colorectal distension (CRD), compliance and propulsive motility] were assessed regularly during the recovery. Colonic histopathology (presence of inflammation, morphometric alterations and variations in neuronal density in the enteric nervous system) 8-week postischaemia was assessed. Following ischaemia, none of the functional parameters tested (motility, sensitivity and compliance) were affected. At necropsy, the colon presented an overall normal appearance with an increase in weight of the ischaemic area (mg/cm: 99 +/- 6; P < 0.05 vs. control: 81 +/- 4 or sham ischaemia: 81 +/- 3). Histopathological evaluations revealed the presence of a local infiltrate of mast cells in the area of ischaemia (nb of mast cells: 142 +/- 50; P < 0.05 vs. control, 31 +/- 14 or sham ischaemia: 40 +/- 16), without other significant alterations. Animals subjected to colonic ischaemia and treated 8 weeks later with the mast cell degranulator, compound 48/80, showed no changes in CRD-related pain responses. These studies show that acute colonic ischaemia is associated with the presence of a long-term local infiltration of mast cells, located within the serosa and muscle layers, despite the absence of functional changes, including colonic sensitivity. Considering the important pathophysiological functions of mast cells, the observed mast cell infiltration may be involved in ischaemia-induced functional changes yet to be characterized.
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Larsson MH, Bayati A, Lindström E, Larsson H. Involvement of kappa-opioid receptors in visceral nociception in mice. Neurogastroenterol Motil 2008; 20:1157-64. [PMID: 18643891 DOI: 10.1111/j.1365-2982.2008.01161.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
It has been shown that the behavioural responses to chemically evoked visceral nociception are increased in transgenic mice lacking the kappa-opioid receptor (KOR). The aim of the present study was to evaluate the contribution of KOR in mechanically evoked visceral pain by performing colorectal distension (CRD) and monitoring the subsequent visceromotor response (VMR) in control mice (KOR(+/+)) and in mice lacking KOR (KOR(-/-)). Pseudo-affective visceral pain responses were evoked in conscious mice using increasing (10-80 mmHg) and repeated (12 x 55 mmHg) phasic CRD paradigms. The resulting VMR was determined by monitoring the electromyographic activity of the abdominal muscle. The increasing and repeated CRD paradigms, respectively, evoked similar responses in both KOR(+/+) and KOR(-/-) mice. The selective KOR-agonists U-69593 (5 and 25 mg kg(-1), s.c.) and asimadoline (25 mg kg(-1), s.c.) significantly decreased the VMR in KOR(+/+) mice, while having no effect in KOR(-/-) mice. In contrast, the selective mu-opioid receptor agonist fentanyl significantly reduced the VMR in both types of mice and appeared more efficacious in KOR(-/-) mice. The opioid receptor antagonist naloxone (0.3-30 mg kg(-1) s.c.) did not affect the response to CRD in C57BL/6 mice at any dose tested. In conclusion, the data confirm that the KOR agonists used in this study inhibit the VMR to CRD in mice by acting via KOR receptors. In addition, the data suggest that the endogenous opioid system is not likely to modulate the VMR to mechanically evoked visceral pain in mice.
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Affiliation(s)
- M H Larsson
- Department of Integrative Pharmacology, Gastrointestinal Biology, AstraZeneca R&D Mölndal, Mölndal, Sweden.
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Ravnefjord A, Brusberg M, Larsson H, Lindström E, Martínez V. Effects of pregabalin on visceral pain responses and colonic compliance in rats. Br J Pharmacol 2008; 155:407-16. [PMID: 18574457 DOI: 10.1038/bjp.2008.259] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND AND PURPOSE Pregabalin, which binds to the alpha2-delta subunit of voltage-gated calcium channels, increased the threshold for pain during colorectal distension (CRD) in irritable bowel syndrome (IBS) patients. We tested the effects of oral pregabalin on the visceral pain-related viscerosomatic and autonomic cardiovascular responses to CRD and colonic compliance in rats. EXPERIMENTAL APPROACH The activity of the abdominal musculature (viscerosomatic response), monitored by electromyography and intracolonic manometry, and changes in blood pressure and heart rate, monitored by telemetry, were assessed simultaneously in conscious rats during CRD. KEY RESULTS Pregabalin (10-200 micromol kg(-1), p.o.) inhibited dose dependently the viscerosomatic response to phasic, noxious CRD (12 distensions at 80 mm Hg). At 200 mumol kg(-1), pregabalin also reduced the increase in blood pressure and heart rate associated with noxious CRD. Moreover, pregabalin (200 micromol kg(-1), p.o.) reduced the visceromotor response to ascending phasic CRD (10-80 mm Hg) and significantly increased the threshold pressure for response. During phasic CRD (2-20 mm Hg), pregabalin (200 micromol kg(-1), p.o.) increased intracolonic volume, resulting in a shift to the left of the pressure-volume relationship curve, indicative of an increase of compliance. CONCLUSIONS AND IMPLICATIONS Pregabalin reduced the viscerosomatic and autonomic responses associated with CRD-induced visceral pain and increased colonic compliance in rats. These observations confirm the analgesic activity of pregabalin on visceral pain and support the translational value of the CRD model to humans. Ligands for the alpha2-delta subunit might represent interesting compounds for the treatment of visceral pain disorders, such as IBS.
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Affiliation(s)
- A Ravnefjord
- AstraZeneca R&D, Integrative Pharmacology--GI Biology, Mölndal, Sweden
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Brusberg M, Ravnefjord A, Lindgreen M, Larsson H, Lindström E, Martinez V. Oral clonidine inhibits visceral pain-related viscerosomatic and cardiovascular responses to colorectal distension in rats. Eur J Pharmacol 2008; 591:243-51. [PMID: 18593580 DOI: 10.1016/j.ejphar.2008.06.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 06/11/2008] [Accepted: 06/15/2008] [Indexed: 01/27/2023]
Abstract
The alpha(2)-adrenoceptor agonist, clonidine, modulates colorectal sensorimotor functions in humans and, given intrathecally, has analgesic effects in the colorectal distension (CRD) model in rats. We tested the effects of systemic clonidine on the visceral pain-related viscerosomatic and autonomic cardiovascular responses to CRD and colonic compliance in rats using clinically relevant CRD protocols. The activity of the abdominal musculature (viscerosomatic response), monitored by electromyography and intracolonic manometry, and changes in arterial blood pressure and heart rate, monitored by telemetry, were assessed simultaneously in conscious rats during CRD. Pressure-volume relationships during CRD served as a measure of colonic compliance. Clonidine (50-200 nmol/kg, p.o.) dose-dependently inhibited the viscerosomatic response to phasic, noxious CRD (12 distension at 80 mm Hg). At 200 nmol/kg clonidine also attenuated the increase in blood pressure (70+/-7% inhibition, P<0.05) and heart rate (67+/-16% inhibition, P<0.05) associated to noxious CRD. Similar effects were observed after i.v. administration. Likewise, clonidine (200 nmol/kg, p.o.) reduced the response to ascending phasic CRD (10-80 mm Hg) and significantly increased the threshold pressure for pain-related responses. Clonidine (50 or 150 nmol/kg, i.p.) did not affect the pressure-volume relationship during phasic CRD (2-20 mm Hg). These results show that systemic clonidine, at doses devoid of visible side effects, has analgesic effects in the CRD model of visceral pain in rats without affecting colonic compliance. These observations confirm the analgesic activity of systemic clonidine on visceral pain, support the translational value of the rat CRD model to humans and show that manometry is more sensitive than electromyography detecting pain-related responses.
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Affiliation(s)
- Mikael Brusberg
- AstraZeneca R&D, Integrative Pharmacology - GI Biology, Mölndal, Sweden
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Martinez V, Melgar S. Lack of colonic-inflammation-induced acute visceral hypersensitivity to colorectal distension in Na(v)1.9 knockout mice. Eur J Pain 2008; 12:934-44. [PMID: 18280187 DOI: 10.1016/j.ejpain.2007.12.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Revised: 12/10/2007] [Accepted: 12/28/2007] [Indexed: 02/06/2023]
Abstract
Tetrodotoxin-resistant voltage-gated sodium channels subtype 9 (Na(v)1.9) are expressed in small-diameter dorsal root ganglion neurons and have been involved in persistent somatic hyperalgesic responses associated with inflammation. We assessed the role of Na(v)1.9 channels on acute colonic inflammation-induced visceral hypersensitivity in conscious mice, using Na(v)1.9 knockout (KO) mice. Colorectal distension (CRD)-induced visceral pain was assessed in conscious wild-type and Na(v)1.9 KO mice (C57Bl/6 background). The mechanical activity of the abdominal muscles during isobaric colorectal distension was used as a measure of visceral pain. Acute colonic inflammation was induced by intracolonic administration of the toll-like receptor (TLR) 7 activator, R-848 (40mug/animal). CRD was performed 5h later, thereafter animals were euthanized and the colonic content of inflammatory mediators assessed. Normal pain responses were similar in Na(v)1.9 KO and wild-type mice. In wild-type mice, R-848 administration increased the response to phasic CRD by 62% compared with vehicle-treated animals (vehicle: 0.16+/-0.04, R-848: 0.26+/-0.03, n=6-7, P<0.05). However, in Na(v)1.9 KO mice, intracolonic R-848 did not affect the response to CRD (0.11+/-0.02, n=7) compared to animals treated with vehicle (0.17+/-0.03, n=5; P>0.05). After R-848 administration, the colonic content of pro-inflammatory cytokines was increased in similar proportion in wild type and Na(v)1.9 KO mice, suggesting the presence of a similar acute inflammatory reaction in both groups of animals. These results suggest that Na(v)1.9 channels do not significantly contribute to normal visceral pain responses to acute colonic mechanical stimulation but may be important for the development of inflammation-related acute visceral hyperalgesic responses.
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Affiliation(s)
- V Martinez
- Integrative Pharmacology, Gastrointestinal Biology, AstraZeneca R&D Mölndal, Mölndal, Sweden.
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Kakol-Palm D, Brusberg M, Sand E, Larsson H, Martinez V, Johansson A, von Mentzer B, Påhlman I, Lindström E. Role of tachykinin NK(1) and NK(2) receptors in colonic sensitivity and stress-induced defecation in gerbils. Eur J Pharmacol 2007; 582:123-31. [PMID: 18234189 DOI: 10.1016/j.ejphar.2007.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2007] [Revised: 11/23/2007] [Accepted: 12/06/2007] [Indexed: 01/02/2023]
Abstract
The pharmacology of tachykinin NK receptors varies greatly among species. The aim of the present study was to assess the role of NK(1) and NK(2) receptors in mediating colorectal distension-evoked nociception and psychological stress-induced defecation in gerbils, a species with human-like NK receptor pharmacology. The effects of the selective NK(1) and NK(2) receptor antagonists, aprepitant and saredutant, on acute (1 h) restraint stress-evoked defecation and plasma adenocorticotropin (ACTH) levels in gerbils were assessed. The effects of antagonists alone or in combination on colorectal distension-evoked visceral pain in conscious gerbils were evaluated using the visceromotor response as a surrogate marker of pain. Restraint stress increased fecal pellet output 2-3-fold and plasma ACTH levels 9-fold. Aprepitant inhibited the defecatory and endocrine responses to stress by 50%, while saredutant completely normalized the same parameters. Visceral pain responses during colorectal distension were attenuated by both compounds, but aprepitant (19+/-6% inhibition, P<0.01) was slightly more effective than saredutant (10+/-9% inhibition, P<0.05). A combination of both compounds resulted in an additive effect (30+/-10% inhibition, P<0.01). The results demonstrate that NK(1) and NK(2) receptors are involved in stress-related colonic motor alterations and visceral pain responses in gerbils and that combined antagonism provides enhanced inhibition of visceral pain responses. This suggests that for therapeutic use in for instance functional gastrointestinal disorders, dual NK(1)/NK(2) receptor antagonists may provide better clinical outcome than selective compounds.
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Lindström E, Brusberg M, Hughes PA, Martin CM, Brierley SM, Phillis BD, Martinsson R, Abrahamsson C, Larsson H, Martinez V, Blackshaw AL. Involvement of metabotropic glutamate 5 receptor in visceral pain. Pain 2007; 137:295-305. [PMID: 17937975 DOI: 10.1016/j.pain.2007.09.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 08/30/2007] [Accepted: 09/10/2007] [Indexed: 12/11/2022]
Abstract
Metabotropic glutamate 5 receptor (mGluR5) antagonists are effective in animal models of inflammatory and neuropathic pain. The involvement of mGluR5 in visceral pain pathways from the gastrointestinal tract is as yet unknown. We evaluated effects of mGluR5 antagonists on the colorectal distension (CRD)-evoked visceromotor (VMR) and cardiovascular responses in conscious rats, and on mechanosensory responses of mouse colorectal afferents in vitro. Sprague-Dawley rats were subjected to repeated, isobaric CRD (12 x 80 mmHg, for 30s with 5 min intervals). The VMR and cardiovascular responses to CRD were monitored. The mGluR5 antagonists MPEP (1-10 micromol/kg, i.v.) and MTEP (1-3 micromol/kg, i.v.) reduced the VMR to CRD dose-dependently with maximal inhibition of 52+/-8% (p<0.01) and 25+/-11% (p<0.05), respectively, without affecting colonic compliance. MPEP (10 micromol/kg, i.v.) reduced CRD-evoked increases in blood pressure and heart rate by 33+/-9% (p<0.01) and 35+/-8% (p<0.05), respectively. Single afferent recordings were made from mouse pelvic and splanchnic nerves of colorectal mechanoreceptors. Circumferential stretch (0-5 g force) elicited slowly-adapting excitation of action potentials in pelvic distension-sensitive afferents. This response was reduced 55-78% by 10 microM MTEP (p<0.05). Colonic probing (2g von Frey hair) activated serosal splanchnic afferents; their responses were reduced 50% by 10 microM MTEP (p<0.01). We conclude that mGluR5 antagonists inhibit CRD-evoked VMR and cardiovascular changes in conscious rats, through an effect, at least in part, at peripheral afferent endings. Thus, mGluR5 participates in mediating mechanically evoked visceral nociception in the gastrointestinal tract.
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Affiliation(s)
- Erik Lindström
- AstraZeneca R&D, Mölndal, Sweden Nerve Gut Research Laboratory, Hanson Institute, Royal Adelaide Hospital, University of Adelaide, Australia Discipline of Medicine, School of Molecular and Biomedical Sciences, University of Adelaide, Australia Discipline of Physiology, School of Molecular and Biomedical Sciences, University of Adelaide, Australia
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Martínez V, Ryttinger M, Kjerling M, Astin-Nielsen M. Characterisation of colonic accommodation in Wistar Kyoto rats with impaired gastric accommodation. Naunyn Schmiedebergs Arch Pharmacol 2007; 376:205-16. [PMID: 17909748 DOI: 10.1007/s00210-007-0195-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Accepted: 09/21/2007] [Indexed: 12/22/2022]
Abstract
Defective colonic and gastric accommodations have been related to altered viscerosensitivity in irritable bowel syndrome and to functional dyspepsia, respectively. We assessed colonic accommodation in rats with impaired gastric accommodation to determine if altered accommodation can be regarded as a widespread pathophysiological alteration within the gastrointestinal (GI) tract. Colonic accommodation during colorectal distension (CRD) was assessed in Wistar Kyoto rats (WKY), an animal model of impaired gastric accommodation, and in Sprague-Dawley (SD) and Wistar rats, considered normal. CRD (10-80 mmHg)-induced visceral pain responses were also evaluated in the same strains of rats. During gastric distension, WKY rats had lower intra-gastric volume (0.96 +/- 0.22 ml) than SD (1.85 +/- 0.19 ml, P < 0.05) or Wistar rats (2.80 +/- 0.26 ml, P < 0.05), indicating impaired gastric accommodation. In the same animals, pressure-volume curves were constructed during CRD as a measure of colonic accommodation. During short-lasting (1 min) phasic CRD (2-20 mmHg), the pressure-volume curve in WKY rats was displaced to the right compared with SD or Wistar rats, indicative of reduced colonic accommodation (maximal volume: SD, 1.22 +/- 0.05 ml; Wistar, 1.07 +/- 0.04 ml; WKY, 0.87 +/- 0.07 ml; P < 0.01). Pre-treatment with atropine normalised the pressure-volume responses in WKY rats. No differences among strains were observed during the 2-min phasic or ramp-tonic CRD. Visceral pain responses during CRD (10-80 mmHg) were, overall, similar in the three strains, although WKY rats showed lower thresholds for pain (28.0 +/- 4.9 mmHg) than SD (42.3 +/- 6.6 mmHg, P = 0.072) or Wistar rats (48.3 +/- 6.0 mmHg, P < 0.05). WKY rats, although having impaired gastric accommodation, have the ability to fully accommodate the colon to increasing pressures. In WKY rats, impaired accommodation of the smooth muscle might not be a widespread phenomenon along the GI tract but rather a local disturbance.
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Affiliation(s)
- Vicente Martínez
- Department of Integrative Pharmacology-Gastrointestinal Biology, AstraZeneca R&D, Mölndal SE-431 83, Sweden.
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Käll E, Lindström E, Martinez V. The serotonin reuptake inhibitor citalopram does not affect colonic sensitivity or compliance in rats. Eur J Pharmacol 2007; 570:203-11. [PMID: 17594902 DOI: 10.1016/j.ejphar.2007.05.032] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Revised: 05/16/2007] [Accepted: 05/22/2007] [Indexed: 12/18/2022]
Abstract
Altered serotonin signaling has been implicated in the pathophysiology of irritable bowel syndrome (IBS). Selective serotonin reuptake inhibitors (SSRI) improve IBS symptoms, although the mechanism of action remains unclear. We assessed the effects of the SSRI, citalopram, on colonic sensitivity and compliance in rats after acute and repeated administration. Colorectal distension was performed in conscious rats. Pressure-volume relationships during colorectal distension (2-20 mmHg), fitted using a power exponential model [Vol=V(max)xexp[-(kappaxRelP)(beta)], were used as a measure of colonic compliance. The visceral pain-related visceromotor response during colorectal distension (10-80 mmHg) was used to assess visceral sensitivity. Pressure-volume curves and visceromotor responses were assessed after acute citalopram (3 or 10 mg/kg, ip) or vehicle and after repeated treatment (7 and 14 days; 3 or 10 mg/kg/day). In vehicle-treated animals, pressure-volume curves were similar over time. Citalopram (acute or repeated treatment) did not affect neither the pressure-volume curves nor the visceromotor response to colorectal distension. Thus, citalopram, after acute or repeated administration, had no significant effects on colon compliance or visceral pain during colorectal distension in rats. These results agree with recent observations in humans suggesting that the therapeutic actions of citalopram in IBS are independent of any effects on colonic sensorimotor function.
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Affiliation(s)
- Erika Käll
- Integrative Pharmacology--Gastrointestinal Biology, AstraZeneca R&D, SE-431 83 Mölndal, Sweden
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Chung EKY, Zhang X, Li Z, Zhang H, Xu H, Bian Z. Neonatal maternal separation enhances central sensitivity to noxious colorectal distention in rat. Brain Res 2007; 1153:68-77. [PMID: 17434464 DOI: 10.1016/j.brainres.2007.03.047] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 03/09/2007] [Accepted: 03/18/2007] [Indexed: 12/28/2022]
Abstract
Psychological stress experienced in early life plays an important role in the development of visceral hyperalgesia in irritable bowel syndrome (IBS). Neonatal maternal separation has been shown to trigger a long-term alternation in stress-induced responses to visceral nociceptive stimuli in rats. The aim of the present study was to show a direct evidence of stress-induced alteration in central neuronal responses to colorectal distention (CRD) in rats by a quantitative study of c-fos expression in relevant brain structures. Male Wistar rat pups were subjected to 180-min daily neonatal maternal separation (NMS) for 13 consecutive days (from PND 2 to PND 14). The expression of c-fos was examined by using immunohistochemistry. Increased c-fos expression was observed, for the first time, in the cingulate cortex (3-fold) in NMS rats in comparison with the control group at basal condition. At noxious CRD (80 mm Hg), c-fos expression was induced in the supraspinal centers and in both the superficial (laminae I-II) and the deeper laminae (laminae V-VI and X) of the spinal cord in rats. Significantly more Fos-IR nuclei were found in the laminae I and II, and laminae V-VI of the lumbarsacral spinal cord, the paraventricular thalamic nucleus, the cingulate cortex, the amygdaloid central nucleus in NMS rats, but not in the solitary tract, the central medial thalamic nucleus, the ventromedial hypothalamic nucleus, and the periaquaductal gray. The present results indicate that NMS has sensitized the cingulate cortex and upregulated the activity of the ascending pathway at spinal level as well as the thalamo-cortico-amydala pathway to CRD. The upregulation and sensitization of these pathways may be responsible for the development of visceral hypersensitivity in IBS.
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Affiliation(s)
- Elaine K Y Chung
- School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China
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39
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Abstract
Measurement of visceral sensitivity in animals is mainly based on 'pseudoaffective' responses, which are brain stem reflexes. For example, in female, but not male rats, acute partial restraint stress induces hypersensitivity to colorectal distension. Mucosal mast cell density increases in rats after nematode infection or maternal deprivation, and both also induce colon hypersensitivity. Significantly, the proximity between nerves and mast cells has been found to be increased in adult rats submitted to maternal deprivation. Protease activation of the proteinase-activated receptor-2 also increases visceral nociception in rats, suggesting that an increase in paracellular permeability may be the primum movens in several animal models of visceral hypersensitivity. Accumulating evidence suggests that sensitization of visceral afferents is not restricted to the presumed nociceptor population, suggesting that most of the mechanosensitive afferent population can contribute to visceral discomfort and pain. Other inflammation-produced changes (e.g. subunit composition of purine-gated P2X channels) in visceral sensory neurones may also contribute to visceral hypersensitivity. This article discusses use of in vivo strategies (and transgenic mouse models) to reveal putative roles in mechanosensitivity and sensitization for molecules not previously considered to have mechanosensory functions.
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Affiliation(s)
- J Fioramonti
- Neurogastroenterology and Nutrition Unit, INRA, Toulouse cedex, France.
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Arvidsson S, Larsson M, Larsson H, Lindström E, Martinez V. Assessment of visceral pain-related pseudo-affective responses to colorectal distension in mice by intracolonic manometric recordings. THE JOURNAL OF PAIN 2006; 7:108-18. [PMID: 16459276 DOI: 10.1016/j.jpain.2005.09.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Revised: 09/09/2005] [Accepted: 09/13/2005] [Indexed: 12/22/2022]
Abstract
UNLABELLED Recently, a new manometric method has been proposed to quantify visceromotor responses (VMR) to colorectal distension (CRD) in rats. This method is based on monitoring pressure changes within the distending balloon during CRD. This study assesses the applicability of such a technique to the quantification of VMRs to CRD in mice. Electrical activity of the abdominal muscles and pressure changes within the distending balloon (mechanical response) were simultaneously recorded in conscious mice during CRD (phasic ascending, 10-80 mm Hg, or repetitive, 55 mm Hg). There was a clear stimulus-response relationship with a strong correlation between electrical and mechanical responses during the ascending (r(2) = 0.899, n = 7) or repetitive phasic CRD (r(2) = 0.926, n = 8). Repetitive phasic distensions (55 mm Hg) increased the mechanical and electrical responses by 71 +/- 20% and 42 +/- 16%, respectively (pulses 10-12 vs. 1-3; n = 8, both P < .01). Atropine (0.5 or 1 mg/kg, subcutaneously) did not affect the mechanical response to CRD. The mu-opioid agonist, fentanyl (0.05 mg/kg, subcutaneously), completely prevented the sensitizing response associated to repetitive distensions. These results show that noninvasive, surgery-free manometry of intracolonic pressure is a reliable method to assess VMRs to CRD in mice. The analgesic effect of compounds could be determined, indicating that the method can be used in pharmacologic studies. PERSPECTIVE The model presented to assess visceral pain in mice allows a broad use of this species in pharmacological studies and will be of use in the characterization of potential targets and new drugs for the treatment of human pathologies with visceral pain arising from the gut as a significant component.
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Affiliation(s)
- Susanne Arvidsson
- Integrative Pharmacology-Gastrointestinal Biology, AstraZeneca R&D Mölndal, Mölndal, Sweden
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