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Hurtado K, Scholpa NE, Schnellmann JG, Schnellmann RG. Serotonin regulation of mitochondria in kidney diseases. Pharmacol Res 2024; 203:107154. [PMID: 38521286 DOI: 10.1016/j.phrs.2024.107154] [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: 11/22/2023] [Revised: 03/12/2024] [Accepted: 03/21/2024] [Indexed: 03/25/2024]
Abstract
Serotonin, while conventionally recognized as a neurotransmitter in the CNS, has recently gained attention for its role in the kidney. Specifically, serotonin is not only synthesized in the kidney, but it also regulates glomerular function, vascular resistance, and mitochondrial homeostasis. Because of serotonin's importance to mitochondrial health, this review is focused on the role of serotonin and its receptors in mitochondrial function in the context of acute kidney injury, chronic kidney disease, and diabetic kidney disease, all of which are characterized by mitochondrial dysfunction and none of which has approved pharmacological treatments. Evidence indicates that activation of certain serotonin receptors can stimulate mitochondrial biogenesis (MB) and restore mitochondrial homeostasis, resulting in improved renal function. Serotonin receptor agonists that induce MB are therefore of interest as potential therapeutic strategies for renal injury and disease. SIGNIFICANCE STATEMENT: Mitochondrial dysfunction is associated with many human renal diseases such as acute kidney injury, chronic kidney disease, and diabetic kidney disease, which are associated with increased morbidity and mortality. Unfortunately, none of these pathologies has an FDA-approved pharmacological intervention, underscoring the urgency of identifying new therapeutics for such disorders. Studies show that induction of mitochondrial biogenesis via serotonin (5-hydroxytryptamine, 5-HT) receptors reduces kidney injury markers, restores mitochondrial and renal function after kidney injury, and decreases mortality, suggesting that targeting 5-HT receptors may be a promising therapeutic avenue for mitochondrial dysfunction in kidney diseases. While numerous reviews describe the importance of mitochondria and mitochondrial quality control mechanisms in kidney disease, the relevance of 5-HT receptor-mediated mitochondrial metabolic modulation in the kidney has yet to be thoroughly explored.
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Affiliation(s)
- Kevin Hurtado
- Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
| | - Natalie E Scholpa
- Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States; Southern VA Healthcare System, Tucson, AZ, United States
| | | | - Rick G Schnellmann
- Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States; Southern VA Healthcare System, Tucson, AZ, United States; Department of Neuroscience, College of Medicine, University of Arizona, Tucson, AZ, United States; Southwest Environmental Health Science Center, University of Arizona, Tucson, AZ, United States; Center for Innovation in Brain Science, University of Arizona, Tucson, AZ, United States.
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2
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Cao Y, Li R, Bai L. Vagal sensory pathway for the gut-brain communication. Semin Cell Dev Biol 2024; 156:228-243. [PMID: 37558522 DOI: 10.1016/j.semcdb.2023.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 06/07/2023] [Accepted: 07/20/2023] [Indexed: 08/11/2023]
Abstract
The communication between the gut and brain is crucial for regulating various essential physiological functions, such as energy balance, fluid homeostasis, immune response, and emotion. The vagal sensory pathway plays an indispensable role in connecting the gut to the brain. Recently, our knowledge of the vagal gut-brain axis has significantly advanced through molecular genetic studies, revealing a diverse range of vagal sensory cell types with distinct peripheral innervations, response profiles, and physiological functions. Here, we review the current understanding of how vagal sensory neurons contribute to gut-brain communication. First, we highlight recent transcriptomic and genetic approaches that have characterized different vagal sensory cell types. Then, we focus on discussing how different subtypes encode numerous gut-derived signals and how their activities are translated into physiological and behavioral regulations. The emerging insights into the diverse cell types and functional properties of vagal sensory neurons have paved the way for exciting future directions, which may provide valuable insights into potential therapeutic targets for disorders involving gut-brain communication.
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Affiliation(s)
- Yiyun Cao
- Chinese Institute for Brain Research, Beijing 102206, China
| | - Rui Li
- Chinese Institute for Brain Research, Beijing 102206, China; State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, 100875, China
| | - Ling Bai
- Chinese Institute for Brain Research, Beijing 102206, China.
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3
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Ullah I, Ayaz M. A re-consideration of neural/receptor mechanisms in chemotherapy-induced nausea and vomiting: current scenario and future perspective. Pharmacol Rep 2023; 75:1126-1137. [PMID: 37584820 DOI: 10.1007/s43440-023-00514-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 07/27/2023] [Accepted: 07/27/2023] [Indexed: 08/17/2023]
Abstract
The neural mechanisms and the receptors behind the course of chemotherapy-induced nausea and vomiting (CINV) are well described and considered mechanistically multifactorial, whereas the neurobiology of nausea is not completely understood yet. Some of the anti-neoplastic medications like cisplatin result in biphasic vomiting response. The acute phase of vomiting is triggered mainly via the release of serotonin from the enterochromaffin (EC) cells in the gastrointestinal tract (GIT) and results in stimulation of dorsal vagal complex (DVC) of the vomiting center and the vomiting is initiated by downward communication to the gut via vagal efferents. Agonism of 5HT3 receptors is majorly involved in the mediation of the acute phase. Therefore, antagonists at 5HT3 receptors are effective in the management of acute-phase vomiting episodes. Likewise, Dopamine type 2 (D2) receptors, dopamine neurotransmitter, Muscarinic receptors (M3), GLP1 receptors, and histaminergic receptors (H1) are also implicated in the vomiting act as well. In continuation, Cannabinoid type 1 (CB1) receptors are also recommended and included in the guidelines as agonism of presynaptically located CB1 receptors inhibits the release of excitatory neurotransmitters responsible for vomiting initiation. The delayed phase involves the release of "Substance P" in the gut and results in the stimulation of neurokinin-1 (NK1) receptors centrally in the area postrema (AP) and nucleus tractus solitarius (NTS), subsequently the vomiting response. The current understanding is the existence of overlapping mechanisms of neurotransmitters, serotonin, dopamine, and substance P throughout the time course of CINV. Furthermore, the emetic neurotransmitters are released via calcium ion (Ca++)-dependent mechanisms, implicating the molecular targets of intracellular Ca++ signaling in emetic circuitry. The current review entails the neurobiology of nausea and vomiting induced by cancer chemotherapeutic agents and the recent approaches in the management.
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Affiliation(s)
- Ihsan Ullah
- Department of Pharmacy, Faculty of Sciences, University of Swabi, Anbar, Swabi, 23430, Khyber Pakhtunkhwa, Pakistan.
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong.
| | - Muhammad Ayaz
- Department of Pharmacy, Faculty of Biological Sciences, University of Malakand, Dir (L), Chakdara, 18000, KP, Pakistan.
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4
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Shulgach JA, Beam DW, Nanivadekar AC, Miller DM, Fulton S, Sciullo M, Ogren J, Wong L, McLaughlin BL, Yates BJ, Horn CC, Fisher LE. Selective stimulation of the ferret abdominal vagus nerve with multi-contact nerve cuff electrodes. Sci Rep 2021; 11:12925. [PMID: 34155231 PMCID: PMC8217223 DOI: 10.1038/s41598-021-91900-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 06/01/2021] [Indexed: 12/14/2022] Open
Abstract
Dysfunction and diseases of the gastrointestinal (GI) tract are a major driver of medical care. The vagus nerve innervates and controls multiple organs of the GI tract and vagus nerve stimulation (VNS) could provide a means for affecting GI function and treating disease. However, the vagus nerve also innervates many other organs throughout the body, and off-target effects of VNS could cause major side effects such as changes in blood pressure. In this study, we aimed to achieve selective stimulation of populations of vagal afferents using a multi-contact cuff electrode wrapped around the abdominal trunks of the vagus nerve. Four-contact nerve cuff electrodes were implanted around the dorsal (N = 3) or ventral (N = 3) abdominal vagus nerve in six ferrets, and the response to stimulation was measured via a 32-channel microelectrode array (MEA) inserted into the left or right nodose ganglion. Selectivity was characterized by the ability to evoke responses in MEA channels through one bipolar pair of cuff contacts but not through the other bipolar pair. We demonstrated that it was possible to selectively activate subpopulations of vagal neurons using abdominal VNS. Additionally, we quantified the conduction velocity of evoked responses to determine what types of nerve fibers (i.e., Aδ vs. C) responded to stimulation. We also quantified the spatial organization of evoked responses in the nodose MEA to determine if there is somatotopic organization of the neurons in that ganglion. Finally, we demonstrated in a separate set of three ferrets that stimulation of the abdominal vagus via a four-contact cuff could selectively alter gastric myoelectric activity, suggesting that abdominal VNS can potentially be used to control GI function.
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Affiliation(s)
- Jonathan A Shulgach
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.,Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Dylan W Beam
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Center for Neural Basis of Cognition, Pittsburgh, PA, 15213, USA
| | - Ameya C Nanivadekar
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Center for Neural Basis of Cognition, Pittsburgh, PA, 15213, USA
| | - Derek M Miller
- Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Stephanie Fulton
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Michael Sciullo
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - John Ogren
- Micro-Leads Inc., Somerville, MA, 02144, USA
| | - Liane Wong
- Micro-Leads Inc., Somerville, MA, 02144, USA
| | | | - Bill J Yates
- Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Charles C Horn
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Lee E Fisher
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA. .,Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15213, USA. .,Center for Neural Basis of Cognition, Pittsburgh, PA, 15213, USA. .,Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
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5
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Linan-Rico A, Ochoa-Cortes F, Beyder A, Soghomonyan S, Zuleta-Alarcon A, Coppola V, Christofi FL. Mechanosensory Signaling in Enterochromaffin Cells and 5-HT Release: Potential Implications for Gut Inflammation. Front Neurosci 2016; 10:564. [PMID: 28066160 PMCID: PMC5165017 DOI: 10.3389/fnins.2016.00564] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 11/22/2016] [Indexed: 12/12/2022] Open
Abstract
Enterochromaffin (EC) cells synthesize 95% of the body 5-HT and release 5-HT in response to mechanical or chemical stimulation. EC cell 5-HT has physiological effects on gut motility, secretion and visceral sensation. Abnormal regulation of 5-HT occurs in gastrointestinal disorders and Inflammatory Bowel Diseases (IBD) where 5-HT may represent a key player in the pathogenesis of intestinal inflammation. The focus of this review is on mechanism(s) involved in EC cell "mechanosensation" and critical gaps in our knowledge for future research. Much of our knowledge and concepts are from a human BON cell model of EC, although more recent work has included other cell lines, native EC cells from mouse and human and intact mucosa. EC cells are "mechanosensors" that respond to physical forces generated during peristaltic activity by translating the mechanical stimulus (MS) into an intracellular biochemical response leading to 5-HT and ATP release. The emerging picture of mechanosensation includes Piezo 2 channels, caveolin-rich microdomains, and tight regulation of 5-HT release by purines. The "purinergic hypothesis" is that MS releases purines to act in an autocrine/paracrine manner to activate excitatory (P2Y1, P2Y4, P2Y6, and A2A/A2B) or inhibitory (P2Y12, A1, and A3) receptors to regulate 5-HT release. MS activates a P2Y1/Gαq/PLC/IP3-IP3R/SERCA Ca2+signaling pathway, an A2A/A2B-Gs/AC/cAMP-PKA signaling pathway, an ATP-gated P2X3 channel, and an inhibitory P2Y12-Gi/o/AC-cAMP pathway. In human IBD, P2X3 is down regulated and A2B is up regulated in EC cells, but the pathophysiological consequences of abnormal mechanosensory or purinergic 5-HT signaling remain unknown. EC cell mechanosensation remains poorly understood.
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Affiliation(s)
- Andromeda Linan-Rico
- Department of Anesthesiology, Wexner Medical Center at Ohio State UniversityColumbus, OH, USA; CONACYT-Centro Universitario de Investigaciones Biomedicas, University of ColimaColima, Mexico
| | - Fernando Ochoa-Cortes
- Department of Anesthesiology, Wexner Medical Center at Ohio State University Columbus, OH, USA
| | - Arthur Beyder
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Department of Physiology and Biomedical Engineering, Mayo Clinic Rochester, MN, USA
| | - Suren Soghomonyan
- Department of Anesthesiology, Wexner Medical Center at Ohio State University Columbus, OH, USA
| | - Alix Zuleta-Alarcon
- Department of Anesthesiology, Wexner Medical Center at Ohio State University Columbus, OH, USA
| | - Vincenzo Coppola
- SBS-Cancer Biology and Genetics, Ohio State University Columbus, OH, USA
| | - Fievos L Christofi
- Department of Anesthesiology, Wexner Medical Center at Ohio State University Columbus, OH, USA
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6
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Measuring the nausea-to-emesis continuum in non-human animals: refocusing on gastrointestinal vagal signaling. Exp Brain Res 2014; 232:2471-81. [PMID: 24862507 DOI: 10.1007/s00221-014-3985-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 05/05/2014] [Indexed: 12/16/2022]
Abstract
Nausea and vomiting are ubiquitous as drug side effects and symptoms of disease; however, the systems that determine these responses are arguably designed for protection against food poisoning occurring at the level of the gastrointestinal (GI) tract. This basic biological pathway using GI vagal afferent communication to the brain is not well understood. Part of this lack of insight appears to be related to current experimental approaches, such as the use of experimental drugs, including systemic chemotherapy and brain penetrant agents, which activate parts of the nausea and vomiting system in potentially unnatural ways. Directly related to this issue is our ability to understand the link between nausea and vomiting, which are sometimes argued to be completely separate processes, with nausea as an unmeasurable response in animal models. An argument is made that nausea and emesis are the efferent limbs of a unified sensory input from the GI tract that is likely to be impossible to understand without more specific animal electrophysiological experimentation of vagal afferent signaling. The current paper provides a review on the use of animal models and approaches to defining the biological systems for nausea and emesis and presents a potentially testable theory on how these systems work in combination.
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7
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Abstract
Serotonin (5-HT) has been recognized for decades as an important signalling molecule in the gut, but it is still revealing its secrets. Novel gastrointestinal functions of 5-HT continue to be discovered, as well as distant actions of gut-derived 5-HT, and we are learning how 5-HT signalling is altered in gastrointestinal disorders. Conventional functions of 5-HT involving intrinsic reflexes include stimulation of propulsive and segmentation motility patterns, epithelial secretion and vasodilation. Activation of extrinsic vagal and spinal afferent fibres results in slowed gastric emptying, pancreatic secretion, satiation, pain and discomfort, as well as nausea and vomiting. Within the gut, 5-HT also exerts nonconventional actions such as promoting inflammation and serving as a trophic factor to promote the development and maintenance of neurons and interstitial cells of Cajal. Platelet 5-HT, originating in the gut, promotes haemostasis, influences bone development and serves many other functions. 5-HT3 receptor antagonists and 5-HT4 receptor agonists have been used to treat functional disorders with diarrhoea or constipation, respectively, and the synthetic enzyme tryptophan hydroxylase has also been targeted. Emerging evidence suggests that exploiting epithelial targets with nonabsorbable serotonergic agents could provide safe and effective therapies. We provide an overview of these serotonergic actions and treatment strategies.
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Abstract
The alimentary canal includes the mouth, stomach, and intestines, and is connected to the brain by thousands of chemosensory neurons. In contrast to the understanding of the lingual taste system, there is little insight into the chemosensory function of other regions of the alimentary canal. The presence of known taste receptors in the gastrointestinal tract suggests a similarity to taste mechanisms present in the oral cavity. Afferent fibers of the vagus play a prominent role in signaling the chemical contents of the gastrointestinal tract to the hindbrain and this information can be used to elicit defensive responses, such as vomiting or nutritional responses. A host of amino acids are likely detected by vagal afferent fibers, but the initial sensory transduction of these stimuli and functional significance remains a mystery. Several problems with recording the electrophysiological signals of vagal afferents are discussed, with particular reference to sampling the afferent signals from the duodenum and liver region.
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Affiliation(s)
- Charles C Horn
- Monell Chemical Senses Center, Philadelphia, Pennsylvania 19104, USA.
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Horn CC. Brain Fos expression induced by the chemotherapy agent cisplatin in the rat is partially dependent on an intact abdominal vagus. Auton Neurosci 2009; 148:76-82. [PMID: 19362521 PMCID: PMC3327482 DOI: 10.1016/j.autneu.2009.03.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2008] [Revised: 03/09/2009] [Accepted: 03/19/2009] [Indexed: 10/20/2022]
Abstract
Anticancer agents such as cisplatin stimulate nausea, vomiting, and behaviors indicative of malaise. Rats and mice, and probably all rodents, do not possess a vomiting response, and their ingestion of kaolin clay (a pica response) has been used as an index of malaise. Similar to the action of cisplatin on emesis in vomiting species, in the rat cisplatin activates vagal afferent fibers, and cisplatin-induced kaolin intake is largely dependent on an intact abdominal vagus. Cisplatin also stimulates Fos expression in the rat brain in areas known to play a role in emesis in other species, but it is not known whether vagal input is required for this CNS activation. In the present study, rats were given abdominal vagotomy or sham operation to test the role of an intact vagus on cisplatin-induced Fos expression 6 h after injection with saline or cisplatin (6 mg/kg, ip). Cisplatin treatment produced Fos expression in the area postrema and multiple levels of the nucleus of the solitary tract (NTS) of sham-operated rats. Vagotomy reduced cisplatin-induced Fos expression in the caudal and middle levels of the NTS and central amygdala. Furthermore, cisplatin did not significantly alter Fos expression in the spinal cord (T8-T10) before or after vagotomy. These results suggest that a defined portion of cisplatin-induced Fos expression is dependent on vagal input, with a majority of this response determined by either direct action of cisplatin or humoral factors on the CNS.
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Affiliation(s)
- Charles C Horn
- Monell Chemical Senses Center, Philadelphia, PA 19104, USA.
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De Jonghe BC, Horn CC. Chemotherapy-induced pica and anorexia are reduced by common hepatic branch vagotomy in the rat. Am J Physiol Regul Integr Comp Physiol 2008; 294:R756-65. [PMID: 18184757 DOI: 10.1152/ajpregu.00820.2007] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Anticancer agents, such as cisplatin, induce vomiting, nausea, and anorexia. Cisplatin primarily acts on vagal afferents to produce emesis, but little is known about how this drug generates nausea and anorexia. Electrophysiology indicates that cisplatin activates vagal afferents of the common hepatic branch (CHB). Rats lack an emetic response but do ingest kaolin clay (a pica response) when made sick by toxins, and this behavior can be inhibited by antiemetic drugs. It has been postulated that pica may serve as a proxy for emesis in the rat. The goal of this study was to assess the effect of CHB or ventral gastric (Gas) or celiac (Cel) branch vagotomies on pica and anorexia produced by cisplatin in the rat. The effects of apomorphine, a dopamine receptor agonist, which induces emesis via a central mechanism, were also assessed. Cisplatin-induced pica was suppressed by CHB vagotomy (a 61% reduction) but not by Gas and Cel vagotomy. Suppression of daily food intake and body weight following cisplatin treatment was also blunted by CHB ablation but not by Gas or Cel vagotomy. No vagotomy condition exhibited altered apomorphine-induced pica. The results indicate that the CHB, which innervates primarily the duodenum, plays an important role in cisplatin-induced malaise. These data suggest that pica has sensory pathways similar to emetic systems, since a vagotomy condition inhibited cisplatin-induced pica but had no effect on apomorphine-induced pica. This investigation contributes to the delineation of the physiology of pica and neural systems involved in malaise in the nonvomiting rat.
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Affiliation(s)
- Bart C De Jonghe
- Monell Chemical Senses Center, 3500 Market St., Philadelphia, PA 19104, USA
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Spiller R. Recent advances in understanding the role of serotonin in gastrointestinal motility in functional bowel disorders: alterations in 5-HT signalling and metabolism in human disease. Neurogastroenterol Motil 2007; 19 Suppl 2:25-31. [PMID: 17620085 DOI: 10.1111/j.1365-2982.2007.00965.x] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) is present in abundance within the gut, most stored in enterochromaffin cell granules. It is released by a range of stimuli, most potently by mucosal stroking. Released 5-HT stimulates local enteric nervous reflexes to initiate secretion and propulsive motility. It also acts on vagal afferents altering motility and in large amounts induces nausea. Rapid reuptake by a specific transporter (serotonin transporter, SERT) limits its diffusion and actions. Abnormally increased 5-HT is found in a range of gastrointestinal disorders including chemotherapy-induced nausea and vomiting, carcinoid syndrome, coeliac disease, inflammatory bowel disease and irritable bowel syndrome (IBS) with diarrhoea (IBS-D), especially that developing following enteric infection. Impaired SERT has been described in IBS-D and might account for some of the increase in mucosal 5-HT availability. 5-HT(3) receptor antagonists inhibit chemotherapy-induced nausea and diarrhoea associated with both carcinoid syndrome and IBS. While IBS-D is associated with increased 5-HT postprandially, IBS with constipation (IBS-C) is associated with impaired 5-HT response and responds to 5-HT(4) agonists such as Prucalopride and 5-HT(4) partial agonists such as Tegaserod.
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Affiliation(s)
- R Spiller
- Professor of Gastroenterology, Wolfson Digestive Diseases Centre, Nottingham, UK.
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Page AJ, Slattery JA, Milte C, Laker R, O'Donnell T, Dorian C, Brierley SM, Blackshaw LA. Ghrelin selectively reduces mechanosensitivity of upper gastrointestinal vagal afferents. Am J Physiol Gastrointest Liver Physiol 2007; 292:G1376-84. [PMID: 17290011 DOI: 10.1152/ajpgi.00536.2006] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Ghrelin is a peptide released from gastric endocrine cells that has an orexigenic effect via a vagal pathway. Here we determine the effect of ghrelin on mechanosensitivity of upper-intestinal vagal afferent fibers in ferret and mouse. The responses of gastroesophageal vagal afferents to graded mechanical stimulation were determined in vitro before and during application of ghrelin to their peripheral endings. Three types of vagal afferent were tested: tension receptors responding to circumferential tension, mucosal receptors responding only to mucosal stroking, and tension/mucosal (TM) receptors in ferret esophagus that responded to both stimuli. In the mouse, ghrelin did not significantly affect the response of mucosal receptors to mucosal stroking with calibrated von Frey hairs. However, it significantly reduced responses of tension receptors to circumferential tension (P < 0.005; two-way ANOVA) by up to 40%. This inhibition was reversed by the ghrelin receptor antagonist [d-Lys-3]-growth hormone-releasing peptide (GHRP)-6. In the ferret, ghrelin significantly reduced the response of mucosal and TM receptors to mucosal stroking with calibrated von Frey hairs. Surprisingly, ghrelin did not significantly alter the response to circumferential tension in either tension or TM receptors. RT-PCR analysis indicated that both ghrelin and its receptor are expressed in vagal afferent cell bodies in mouse nodose ganglia. In conclusion, ghrelin selectively inhibits subpopulations of mechanically sensitive gastroesophageal vagal afferents; there is also potential for ghrelin release from vagal afferents. However, the subpopulation of afferents inhibited differs between species. These data have broad implications for ghrelin's role in food intake regulation and reflex control of gastrointestinal function.
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Affiliation(s)
- Amanda J Page
- Nerve-Gut Research Laboratory, Department of Gastroenterology, Hepatology and General Medicine, Royal Adelaide Hospital, University of Adelaide, Adelaide, SA 5000, Australia.
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Andrews PLR, Horn CC. Signals for nausea and emesis: Implications for models of upper gastrointestinal diseases. Auton Neurosci 2006; 125:100-15. [PMID: 16556512 PMCID: PMC2658708 DOI: 10.1016/j.autneu.2006.01.008] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2006] [Revised: 01/14/2006] [Accepted: 01/14/2006] [Indexed: 12/12/2022]
Abstract
Nausea and vomiting are amongst the most common symptoms encountered in medicine as either symptoms of diseases or side effects of treatments. In a more biological setting they are also important components of an organism's defences against ingested toxins. Identification of treatments for nausea and vomiting and reduction of emetic liability of new therapies has largely relied on the use of animal models, and although such models have proven invaluable in identification of the anti-emetic effects of both 5-hydroxytryptamine(3) and neurokinin(1) receptor antagonists selection of appropriate models is still a matter of debate. The present paper focuses on a number of controversial issues and gaps in our knowledge in the study of the physiology of nausea and vomiting including: The choice of species for the study of emesis and the underlying behavioural (e.g. neophobia), anatomical (e.g. elongated, narrow abdominal oesophagus with reduced ability to shorten) and physiological (e.g. brainstem circuitry) mechanisms that explain the lack of a vomiting reflex in certain species (e.g. rats); The choice of response to measure (emesis[retching and vomiting], conditioned flavour avoidance or aversion, ingestion of clay[pica], plasma hormone levels[e.g. vasopressin], gastric dysrhythmias) and the relationship of these responses to those observed in humans and especially to the sensation of nausea; The stimulus coding of nausea and emesis by abdominal visceral afferents and especially the vagus-how do the afferents encode information for normal postprandial sensations, nausea and finally vomiting?; Understanding the central processing of signals for nausea and vomiting is particularly problematic in the light of observations that vomiting is more readily amenable to pharmacological treatment than is nausea, despite the assumption that nausea represents "low" intensity activation of pathways that can evoke vomiting when stimulated more intensely.
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Affiliation(s)
- Paul L R Andrews
- Division of Basic Medical Sciences, St George's University of London, Cranmer Terrace, London, SW 17 0RE, UK.
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14
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Malik NM, Moore GBT, Smith G, Liu YL, Sanger GJ, Andrews PLR. Behavioural and hypothalamic molecular effects of the anti-cancer agent cisplatin in the rat: A model of chemotherapy-related malaise? Pharmacol Biochem Behav 2006; 83:9-20. [PMID: 16443263 DOI: 10.1016/j.pbb.2005.11.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Revised: 10/12/2005] [Accepted: 11/30/2005] [Indexed: 10/25/2022]
Abstract
Many cancer patients receiving chemotherapy experience fatigue, disturbed circadian rhythms, anorexia and a variety of dyspeptic symptoms including nausea. There is no animal model for this 'chemotherapy-related malaise' so we investigated the behavioural and molecular effects of a potent chemotherapeutic agent, cisplatin (CP, 6 mg/kg, i.p.) in rats. Dark-phase horizontal locomotor activity declined post-CP reaching a nadir on day 3 (P < 0.001), before recovering after 7 days. CP's effect was most marked in the late part (05.00-07.00) of the dark-phase. Food intake reached a nadir (P > 0.001) at 2 days, coincident with an increase in gastric contents (cisplatin 9.04+/-0.8 vs. saline 2.32+/-0.3 g; P < 0.001). No changes occurred in hypothalamic mRNA expression for AGRP, NPY, HCRT, CRH, IL-1, IL-6, TNFalpha, ABCG1, SLC6A4, PPIA and HPRT mRNA but tryptophan hydroxylase (TPH) mRNA was decreased (47%, P < 0.05) at day 21 post-CP. This shows that despite marked behavioural effects of cisplatin, only a discrete change (TPH) was found in hypothalamic mRNA expression and that occurred when the animals' behaviour had recovered. Findings are discussed in relation to the neuropharmacology of chemotherapy-induced malaise.
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Affiliation(s)
- N M Malik
- Division of Basic Medical Sciences, St. George's University of London, London, SWl7 ORE, Harlow, Essex CMl9 5AW, UK
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Horn CC, Friedman MI. Thoracic cross-over pathways of the rat vagal trunks. Brain Res 2005; 1060:153-61. [PMID: 16197931 PMCID: PMC2637110 DOI: 10.1016/j.brainres.2005.08.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Revised: 08/24/2005] [Accepted: 08/28/2005] [Indexed: 10/25/2022]
Abstract
It is very difficult to study the independent contributions of the afferent and efferent pathways of the subdiaphragmatic vagus to physiology and behavior. Total subdiaphragmatic vagotomy can confound the interpretation of experimental results because it destroys both afferent and efferent vagal fibers. One approach to address this problem involves producing a total ablation of afferent (or efferent) vagal fibers while retaining half of the efferent (or afferent) vagal fibers by making a unilateral rhizotomy plus contralateral subdiaphragmatic vagotomy. However, the completeness of this afferent (or efferent) lesion is based on the assumption that there are no cross-over pathways within the thoracic cavity between the vagal trunks of the rat. To directly test for the presence of vagal cross-over pathways in the rat, we recorded the compound action potentials from the ventral and dorsal trunks of the subdiaphragmatic vagus following electrical stimulation of the left or right cervical vagi. C-fiber cross-over pathways comprised an average of 9% of the total nerve responses (range was 0 to 29%, n = 20). Direct application of the anesthetic bupivacaine to the vagus completely blocked the recorded signals. The vagal cross-over pathways were also demonstrated using capsaicin as a stimulus. These results indicate the presence of thoracic cross-over pathways between vagal trunks in the rat and demonstrate that for most animals it is not possible to produce a "complete" ablation of afferent (or efferent) components of the subdiaphragmatic vagus using unilateral rhizotomy combined with contralateral subdiaphragmatic vagotomy.
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Affiliation(s)
- Charles C Horn
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
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Sato N, Kanai S, Takano S, Kurosawa M, Funakoshi A, Miyasaka K. Central administration of ghrelin stimulates pancreatic exocrine secretion via the vagus in conscious rats. ACTA ACUST UNITED AC 2004; 53:443-9. [PMID: 15040854 DOI: 10.2170/jjphysiol.53.443] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Ghrelin, a novel growth-hormone releasing peptide, was originally isolated from rat and human stomach. Immunohistochemical analyses revealed that ghrelin-immunoreactive neurons were localized in the hypothalamic arcuate nucleus. The function of the digestive organs is controlled from the central nervous system, and the vagus nerve plays an important role. Intracerebroventricular and intravenous administration of ghrelin significantly increased gastric acid secretion, and its effect was abolished by vagotomy. In the present study, the effect of centrally injected ghrelin on pancreatic exocrine secretion was examined in conscious rats. Moreover, an electrophysiologic study was conducted in anesthetized rats to examine whether the excitation of vagal efferent nerve could be induced by ghrelin. To determine the pancreatic exocrine secretion, rats were prepared with cannulae draining bile and pancreatic juice separately. The experiments were conducted in conscious rats on day 4 or 5 after the operation. To exclude the involvement of gastric acid, a proton pump inhibitor omeprazole (5 micromol/kg) was administered into the duodenum 1 h before ghrelin injection. An intracerebroventricular administration of ghrelin (12, 60, and 300 pmol/10 microl) significantly increased pancreatic fluid and protein output in a dose-dependent manner. Pretreatment with the ganglion blocker hexamethonium and with atropine completely abolished the stimulatory effect of central ghrelin. In contrast, an intravenous injection of ghrelin (300 pmol/10 microl) had no effect. Centrally administered ghrelin stimulated the vagal efferent nerve in anesthetized rats. In conclusion, centrally administered ghrelin stimulates pancreatic exocrine secretion through the vagal efferent nerve, and the stimulatory action is independent of gastric acid secretion.
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Affiliation(s)
- Norikazu Sato
- Department of Clinical Physiology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015 Japan
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Horn CC, Richardson EJ, Andrews PLR, Friedman MI. Differential effects on gastrointestinal and hepatic vagal afferent fibers in the rat by the anti-cancer agent cisplatin. Auton Neurosci 2004; 115:74-81. [PMID: 15507408 DOI: 10.1016/j.autneu.2004.08.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2004] [Revised: 08/27/2004] [Accepted: 08/28/2004] [Indexed: 10/26/2022]
Abstract
Cisplatin, a cancer chemotherapy agent, like many toxins, produces emesis and nausea. Abdominal vagotomy, or treatment with 5-HT3 receptor antagonists, blocks cisplatin-induced emesis, which suggests that it produces (albeit indirectly) activation of 5-HT3 receptors on vagal afferent fibers. Cisplatin induces a large release of intestinal 5-hydroxytryptamine (5-HT) that enters the hepatic portal vein, which may activate vagal afferent fibers in the portal vein or liver to induce emesis or other side effects of treatment (e.g., reduced food intake). This study was conducted to assess the effects of cisplatin on gastrointestinal and portal vein/liver vagal afferent fibers by recording the neurophysiological responses of the common hepatic branch (CHB) of the vagus in the rat. The CHB contains vagal afferent fibers that innervate the gastrointestinal (GI) tract, portal vein, and liver. Cisplatin (10 mg/kg; jugular vein, j.v.) produced an increase in multi-unit CHB activity and this effect was blocked by a 5-HT3-receptor antagonist (Y-25130, 0.8 mg, j.v.). Cutting the gastroduodenal branch (GDB), a sub-branch of the CHB that contains GI afferent fibers, resulted in a complete suppression of the multi-unit CHB discharge produced by cisplatin treatment. Single units that were cisplatin sensitive had their activity reduced by either 5-HT3 receptor antagonist treatment or cutting the GDB. Conversely, cisplatin insensitive units were not affected by 5-HT3-antagonism or GDB ablation. The present results indicate that cisplatin activates GI vagal afferent fibers via 5-HT3 receptors but does not affect portal vein/liver vagal afferent fibers, which indicates that intestinal but not hepatic afferent fibers are involved in the toxic effects of cisplatin.
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Affiliation(s)
- Charles C Horn
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
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Miyasaka K, Masuda M, Kanai S, Sato N, Kurosawa M, Funakoshi A. Central Orexin-A stimulates pancreatic exocrine secretion via the vagus. Pancreas 2002; 25:400-4. [PMID: 12409836 DOI: 10.1097/00006676-200211000-00013] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
INTRODUCTION Digestive organs are controlled from the central nervous system, and the vagus nerve plays an important role. Orexins are recently purified neuropeptides localized in neurons within the lateral hypothalamus. AIM To examine the effects of centrally injected Orexin-A and B on pancreatic exocrine secretion in conscious rats. METHODOLOGY Rats were prepared with cannulae draining bile and pancreatic juice separately. The experiments were conducted without anesthesia on day 4 or 5 after the operation. RESULTS Intracerebroventricular administration of Orexin-A (0.25, 0.5, and 1.0 nmol) significantly increased pancreatic fluid and protein output in a dose-dependent manner. A significant stimulatory effect of Orexin-B was not observed. Pretreatment with the ganglion blocker hexamethonium and with atropine completely abolished the stimulatory effect of central Orexin-A. Central Orexin-A significantly increased pancreatic secretion after pretreatment with omeprazole. Intravenous injection of Orexin-A had no effect. Centrally administered Orexin-A stimulated the vagal efferent nerve in anesthetized rats. CONCLUSIONS Centrally administered Orexin-A stimulates pancreatic exocrine secretion through the vagal efferent nerve, and the stimulatory action is independent of gastric acid secretion.
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Affiliation(s)
- Kyoko Miyasaka
- Department of Clinical Physiology, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
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Horn CC, Tordoff MG, Friedman MI. Role of vagal afferent innervation in feeding and brain Fos expression produced by metabolic inhibitors. Brain Res 2001; 919:198-206. [PMID: 11701132 DOI: 10.1016/s0006-8993(01)02963-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hepatic vagal afferent fibers have been implicated in the feeding responses initiated by administration of 2,5-anhydro-D-mannitol (2,5-AM; an inhibitor of hepatic metabolism) and methyl palmoxirate (MP; an inhibitor of fat metabolism). 2,5-AM and MP also increase brain Fos expression, an indicator of neural activity, which suggests that Fos expression can reveal the central neural pathways involved in the stimulation of feeding by these agents. To more closely test the hypothesis that brain Fos expression is related to the effects of 2,5-AM and MP on feeding, the vagus was lesioned by application of capsaicin, which destroys afferent fibers, directly to the cervical vagi. Perivagal capsaicin treatment blocked 2,5-AM-induced eating and attenuated MP-induced eating. Although perivagal capsaicin treatment attenuated MP-induced Fos expression, capsaicin treatment did not affect brain Fos expression produced by 2,5-AM. It is concluded that (1) brain Fos expression is not always related to the effects of 2,5-AM on feeding, (2) capsaicin-sensitive hepatic vagal afferent fibers carry the signal that stimulates feeding following 2,5-AM treatment, and (3) MP-induced feeding and brain Fos expression is mediated in part by capsaicin-sensitive fibers.
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Affiliation(s)
- C C Horn
- Monell Chemical Senses Center, Philadelphia, PA 19104, USA.
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Jiang W, Kreis ME, Eastwood C, Kirkup AJ, Humphrey PP, Grundy D. 5-HT(3) and histamine H(1) receptors mediate afferent nerve sensitivity to intestinal anaphylaxis in rats. Gastroenterology 2000; 119:1267-75. [PMID: 11054384 DOI: 10.1053/gast.2000.19461] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS The mechanisms underlying brain stem activation during antigen challenge have not been resolved. Our aim was to characterize afferent nerve responses to intestinal anaphylaxis and determine the mediators involved in afferent activation. METHODS Mesenteric afferent discharge was recorded electrophysiologically after intestinal anaphylaxis in anesthetized rats previously sensitized to chicken egg albumin (EA). RESULTS Mesenteric afferent nerve discharge increased approximately 1 minute after luminal antigen but not bovine serum albumin (P < 0.001, EA vs. bovine serum albumin). Subsequent administration of antigen had no effect, but systemic EA evoked a marked increase in afferent discharge (P < 0. 05). Afferent responses were unrelated to intestinal motor activity, and the response to luminal antigen was attenuated by luminal anesthetic (1% lidocaine). The 5-HT(3)-receptor antagonist alosetron (30 microg. kg(-1)) and the histamine H(1)-receptor antagonist pyrilamine (5 mg. kg(-1)) markedly attenuated the response to luminal antigen; pretreatment with doxantrazole attenuated responses to both luminal and systemic antigen. CONCLUSIONS 5-HT(3) and histamine, released from mast cells after intestinal anaphylaxis, stimulate mesenteric afferents via 5-HT(3) and histamine H(1) receptors. Information on intestinal immune status is rapidly relayed to the central nervous system and may play a role in neural reflexes and behavioral responses following activation of the immune system.
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Affiliation(s)
- W Jiang
- Department of Biomedical Science, University of Sheffield, Sheffield, England
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Hillsley K, Eeckhout C, Grundy D. Cilansetron acts at its site of absorption to antagonize the sensitivity of mesenteric afferent fibres to 5-hydroxytryptamine in the rat jejunum. Neurosci Lett 2000; 278:137-40. [PMID: 10653012 DOI: 10.1016/s0304-3940(99)00923-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The present study compares the efficacy of cilansetron, a 5-hydroxytryptamine (5-HT3)-receptor antagonist, delivered via intravenous and intraluminal routes, on the sensitivity of mesenteric afferent fibres supplying the proximal jejunum. Waveform analysis was performed to extract 5-HT sensitive single units from electrophysiological recordings of whole afferent nerve discharge. Dose effects of intravenous cilansetron (0.2-20 microg/kg) on the afferent response to 5-HT (10 microg) were examined to determine the threshold dose of cilansetron (2 microg/kg). This dose applied intraluminally to the region of jejunum innervated by the afferents, resulted in a greater degree of antagonism of the 5-HT response than intravenous administration (47.8+/-7.9 vs. 76.9+/-4.7%, P = 0.008). We concluded that cilansetron is active at its site of absorption to antagonize 5-HT3 receptors on vagal mucosal afferent terminals.
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Affiliation(s)
- K Hillsley
- Department of Biomedical Science, University of Sheffield, UK
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