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López-Tofiño Y, Barragán del Caz LF, Benítez-Álvarez D, Molero-Mateo P, Nurgali K, Vera G, Bagües A, Abalo R. Contractility of isolated colonic smooth muscle strips from rats treated with cancer chemotherapy: differential effects of cisplatin and vincristine. Front Neurosci 2023; 17:1304609. [PMID: 38192512 PMCID: PMC10773793 DOI: 10.3389/fnins.2023.1304609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/27/2023] [Indexed: 01/10/2024] Open
Abstract
Background Certain antineoplastic drugs cause gastrointestinal disorders even after the end of treatment. Enteric neuropathy has been associated with some of these alterations. Our goal was to assess the impact of repeated treatment with cisplatin and vincristine on the contractility of circular and longitudinal muscle strips isolated from the rat colon. Methods Two cohorts of male rats were used: in cohort 1, rats received one intraperitoneal (ip) injection of saline or cisplatin (2 mg kg-1 week-1) on the first day of weeks 1-5; in cohort 2, rats received two cycles of five daily ip injections (Monday to Friday, weeks 1-2) of saline or vincristine (0.1 mg kg-1 day-1). Body weight and food and water intake were monitored throughout the study. One week after treatment, responses of colonic smooth muscle strips to acetylcholine (10-9-10-5 M) and electrical field stimulation (EFS, 0.1-20 Hz), before and after atropine (10-6 M), were evaluated in an organ bath. Results Both drugs decreased body weight gain. Compared to saline, cisplatin significantly decreased responses of both longitudinal and circular smooth muscle strips to EFS, whereas vincristine tended to increase them, although in a non-significant manner. No differences were observed in the muscle response to acetylcholine. Atropine abolished the contractile responses induced by acetylcholine, although those induced by EFS were only partially reduced in the presence of atropine. Conclusion The findings suggest that although both drugs cause the development of enteric neuropathy, this seems to have a functional impact only in cisplatin-treated animals. Understanding the effects of chemotherapy on gastrointestinal motor function is vital for enhancing the quality of life of cancer patients.
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Affiliation(s)
- Yolanda López-Tofiño
- Department of Basic Health Sciences, University Rey Juan Carlos (URJC), Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut), University Rey Juan Carlos (URJC), Alcorcón, Spain
- International Doctoral School, URJC, Móstoles, Spain
| | | | - David Benítez-Álvarez
- Department of Basic Health Sciences, University Rey Juan Carlos (URJC), Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut), University Rey Juan Carlos (URJC), Alcorcón, Spain
| | - Paula Molero-Mateo
- International Doctoral School, URJC, Móstoles, Spain
- Lescer Center (Neurological Rehabilitation), Madrid, Spain
- Department of Physiotherapy, Occupational Therapy, Rehabilitation and Physical Medicine, URJC, Alcorcón, Spain
| | - Kulmira Nurgali
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
- Department of Medicine Western Health, The University of Melbourne, Melbourne, VIC, Australia
- Regenerative Medicine and Stem Cell Program, Australian Institute for Musculoskeletal Science (AIMSS), Melbourne, VIC, Australia
| | - Gema Vera
- Department of Basic Health Sciences, University Rey Juan Carlos (URJC), Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut), University Rey Juan Carlos (URJC), Alcorcón, Spain
- Associated I+D+i Unit to the Institute of Medicinal Chemistry (IQM), Scientific Research Superior Council (CSIC), Madrid, Spain
| | - Ana Bagües
- Department of Basic Health Sciences, University Rey Juan Carlos (URJC), Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut), University Rey Juan Carlos (URJC), Alcorcón, Spain
- Associated I+D+i Unit to the Institute of Medicinal Chemistry (IQM), Scientific Research Superior Council (CSIC), Madrid, Spain
- High Performance Research Group in Experimental Pharmacology (PHARMAKOM-URJC), URJC, Alcorcón, Spain
| | - Raquel Abalo
- Department of Basic Health Sciences, University Rey Juan Carlos (URJC), Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut), University Rey Juan Carlos (URJC), Alcorcón, Spain
- Associated I+D+i Unit to the Institute of Medicinal Chemistry (IQM), Scientific Research Superior Council (CSIC), Madrid, Spain
- Working Group of Basic Sciences on Pain and Analgesia of the Spanish Pain Society, Madrid, Spain
- Working Group of Basic Sciences on Cannabinoids of the Spanish Pain Society, Madrid, Spain
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Humenick A, Chen BN, Lauder CIW, Wattchow DA, Zagorodnyuk VP, Dinning PG, Spencer NJ, Costa M, Brookes SJH. Characterization of projections of longitudinal muscle motor neurons in human colon. Neurogastroenterol Motil 2019; 31:e13685. [PMID: 31355986 DOI: 10.1111/nmo.13685] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 07/07/2019] [Accepted: 07/08/2019] [Indexed: 12/08/2022]
Abstract
BACKGROUND The enteric nervous system contains inhibitory and excitatory motor neurons which modulate smooth muscle contractility. Cell bodies of longitudinal muscle motor neurons have not been identified in human intestine. METHODS We used retrograde tracing ex vivo with DiI, with multiple labeling immunohistochemistry, to characterize motor neurons innervating tenial and inter-tenial longitudinal muscle of human colon. KEY RESULTS The most abundant immunohistochemical markers in the tertiary plexus were vesicular acetylcholine transporter, nitric oxide synthase (NOS), and vasoactive intestinal polypeptide (VIP). Of retrogradely traced motor neurons innervating inter-tenial longitudinal muscle, 95% were located within 6mm oral or anal to the DiI application site. Excitatory motor neuron cell bodies, immunoreactive for choline acetyltransferase (ChAT), were clustered aborally, whereas NOS-immunoreactive cell bodies were distributed either side of the DiI application site. Motor neurons had small cell bodies, averaging 438 + 18µm2 in cross-sectional area, similar for ChAT- and NOS-immunoreactive subtypes. Motor neurons innervating the tenia had slightly longer axial projections, with 95% located within 9mm. ChAT-immunoreactive excitatory motor neurons to tenia were clustered aborally, whereas NOS-immunoreactive inhibitory motor neurons had both ascending and descending projections. VIP immunoreactivity was rarely present without NOS immunoreactivity in motor neurons. CONCLUSIONS AND INFERENCES Tenial and inter-tenial motor neurons innervating the longitudinal muscle have short projections. Inhibitory motor neurons have less polarized projections than cholinergic excitatory motor neurons. Longitudinal and circular muscle layers are innervated by distinct local populations of excitatory and inhibitory motor neurons. A population of human enteric neurons that contribute significantly to colonic motility has been characterized.
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Affiliation(s)
- Adam Humenick
- Human Physiology, Medical Bioscience, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Bao Nan Chen
- Human Physiology, Medical Bioscience, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Chris I W Lauder
- Department of Surgery, Flinders Medical Centre, Adelaide, SA, Australia
| | - David A Wattchow
- Department of Surgery, Flinders Medical Centre, Adelaide, SA, Australia
| | - Vladimir P Zagorodnyuk
- Human Physiology, Medical Bioscience, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Phil G Dinning
- Department of Surgery, Flinders Medical Centre, Adelaide, SA, Australia
| | - Nick J Spencer
- Human Physiology, Medical Bioscience, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Marcello Costa
- Human Physiology, Medical Bioscience, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Simon J H Brookes
- Human Physiology, Medical Bioscience, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
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Chakrabarty B, Bijos DA, Vahabi B, Clavica F, Kanai AJ, Pickering AE, Fry CH, Drake MJ. Modulation of Bladder Wall Micromotions Alters Intravesical Pressure Activity in the Isolated Bladder. Front Physiol 2019; 9:1937. [PMID: 30687132 PMCID: PMC6335571 DOI: 10.3389/fphys.2018.01937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 12/21/2018] [Indexed: 12/20/2022] Open
Abstract
Micromotions are phasic contractions of the bladder wall. During urine storage, such phasic activity has little effect on intravesical pressure, however, changed motile activity may underlie urodynamic observations such as detrusor overactivity. The potential for bladder motility to affect pressure reflects a summation of the overall movements, comprising the initiation, propagation, and dissipation components of micromotions. In this study, the influence of initiation of micromotions was investigated using calcium activated chloride channel blocker niflumic acid, and the effect of propagation using blockers of gap junctions. The overall bladder tone was modulated using isoprenaline. Isolated tissue strips and whole bladder preparations from juvenile rats were used. 18β-glycyrrhetinic acid was used to block gap junctions, reducing the amplitude and frequency of micromotions in in vitro and ex vivo preparations. Niflumic acid reduced the frequency of micromotions but had no effect on the amplitude of pressure fluctuations. Isoprenaline resulted in a reduction in pressure fluctuations and a decrease in pressure baseline. Using visual video data analysis, bladder movement was visible, irrespective of lack of pressure changes, which persisted during bladder relaxation. However, micromotions propagated over shorter distances and the overall bladder tone was reduced. All these results suggest that phasic activity of the bladder can be characterised by a combination of initiation and propagation of movement, and overall bladder tone. At any given moment, intravesical pressure recordings are an integration of these parameters. This synthesis gives insight into the limitations of clinical urodynamics, where intravesical pressure is the key indicator of detrusor activity.
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Affiliation(s)
- Basu Chakrabarty
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
| | - Dominika A Bijos
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom.,Southmead Hospital, Bristol Urological Institute, Bristol, United Kingdom
| | - Bahareh Vahabi
- Department of Applied Sciences, University of West England, Bristol, Bristol, United Kingdom
| | - Francesco Clavica
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
| | - Anthony J Kanai
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Anthony E Pickering
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom.,Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Christopher H Fry
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
| | - Marcus J Drake
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom.,Southmead Hospital, Bristol Urological Institute, Bristol, United Kingdom
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Hibberd TJ, Costa M, Travis L, Brookes SJH, Wattchow DA, Feng J, Hu H, Spencer NJ. Neurogenic and myogenic patterns of electrical activity in isolated intact mouse colon. Neurogastroenterol Motil 2017; 29:1-12. [PMID: 28418103 DOI: 10.1111/nmo.13089] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/16/2017] [Indexed: 01/02/2023]
Abstract
BACKGROUND Relatively little is known about the electrical rhythmicity of the whole colon, where long neural pathways are preserved. METHODS Smooth muscle electrical activity was recorded extracellularly from the serosa of isolated flat-sheet preparations consisting of the whole mouse colon (n=31). KEY RESULTS Two distinct electrical patterns were observed. The first, long intense spike bursts, occurred every 349±256 seconds (0.2±0.2 cpm), firing action potentials for 31±11 seconds at 2.1±0.5 Hz. They were hexamethonium- and tetrodotoxin-sensitive, but persisted in nicardipine as 2 Hz electrical oscillations lacking action potentials. This pattern is called here neurogenic spike bursts. The second pattern, short spike bursts, occurred about every 30 seconds (2.0±0.6 cpm), with action potentials firing at about 1 Hz for 9 seconds (1.0±0.2 Hz, 9±4 seconds). Short spike bursts were hexamethonium- and tetrodotoxin-resistant but nicardipine-sensitive and thus called here myogenic spike bursts. Neurogenic spike bursts transiently delayed myogenic spike bursts, while blocking neurogenic activity enhanced myogenic spike burst durations. External stimuli significantly affected neurogenic but not myogenic spike bursts. Aboral electrical or mechanical stimuli evoked premature neurogenic spike bursts. Circumferential stretch significantly decreased intervals between neurogenic spike bursts. Lesioning the colon down to 10 mm segments significantly increased intervals or abolished neurogenic spike bursts, while myogenic spike bursts persisted. CONCLUSIONS & INFERENCES Distinct neurogenic and myogenic electrical patterns were recorded from mouse colonic muscularis externa. Neurogenic spike bursts likely correlate with neurogenic colonic migrating motor complexes (CMMC) and are highly sensitive to mechanical stimuli. Myogenic spike bursts may correspond to slow myogenic contractions, whose duration can be modulated by enteric neural activity.
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Affiliation(s)
- T J Hibberd
- Discipline of Human Physiology & Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
| | - M Costa
- Discipline of Human Physiology & Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
| | - L Travis
- Discipline of Human Physiology & Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
| | - S J H Brookes
- Discipline of Human Physiology & Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
| | - D A Wattchow
- Discipline of Surgery & Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
| | - J Feng
- Department of Anesthesiology, The Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA
| | - H Hu
- Department of Anesthesiology, The Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA
| | - N J Spencer
- Discipline of Human Physiology & Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
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Robinson AM, Rahman AA, Carbone SE, Randall-Demllo S, Filippone R, Bornstein JC, Eri R, Nurgali K. Alterations of colonic function in the Winnie mouse model of spontaneous chronic colitis. Am J Physiol Gastrointest Liver Physiol 2017; 312:G85-G102. [PMID: 27881401 DOI: 10.1152/ajpgi.00210.2016] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 11/14/2016] [Accepted: 11/14/2016] [Indexed: 01/31/2023]
Abstract
UNLABELLED The Winnie mouse, carrying a missense mutation in Muc2, is a model for chronic intestinal inflammation demonstrating symptoms closely resembling inflammatory bowel disease (IBD). Alterations to the immune environment, morphological structure, and innervation of Winnie mouse colon have been identified; however, analyses of intestinal transit and colonic functions have not been conducted. In this study, we investigated in vivo intestinal transit in radiographic studies and in vitro motility of the isolated colon in organ bath experiments. We compared neuromuscular transmission using conventional intracellular recording between distal colon of Winnie and C57BL/6 mice and smooth muscle contractions using force displacement transducers. Chronic inflammation in Winnie mice was confirmed by detection of lipocalin-2 in fecal samples over 4 wk and gross morphological damage to the colon. Colonic transit was faster in Winnie mice. Motility was altered including decreased frequency and increased speed of colonic migrating motor complexes and increased occurrence of short and fragmented contractions. The mechanisms underlying colon dysfunctions in Winnie mice included inhibition of excitatory and fast inhibitory junction potentials, diminished smooth muscle responses to cholinergic and nitrergic stimulation, and increased number of α-smooth muscle actin-immunoreactive cells. We conclude that diminished excitatory responses occur both prejunctionally and postjunctionally and reduced inhibitory purinergic responses are potentially a prejunctional event, while diminished nitrergic inhibitory responses are probably due to a postjunction mechanism in the Winnie mouse colon. Many of these changes are similar to disturbed motor functions in IBD patients indicating that the Winnie mouse is a model highly representative of human IBD. NEW & NOTEWORTHY This is the first study to provide analyses of intestinal transit and whole colon motility in an animal model of spontaneous chronic colitis. We found that cholinergic and purinergic neuromuscular transmission, as well as the smooth muscle cell responses to cholinergic and nitrergic stimulation, is altered in the chronically inflamed Winnie mouse colon. The changes to intestinal transit and colonic function we identified in the Winnie mouse are similar to those seen in inflammatory bowel disease patients.
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Affiliation(s)
- Ainsley M Robinson
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
| | - Ahmed A Rahman
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
| | - Simona E Carbone
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
| | - Sarron Randall-Demllo
- University of Tasmania, School of Health Sciences, Launceston, Tasmania, Australia; and
| | - Rhiannon Filippone
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
| | - Joel C Bornstein
- Department of Physiology, Melbourne University, Melbourne, Victoria, Australia
| | - Rajaraman Eri
- University of Tasmania, School of Health Sciences, Launceston, Tasmania, Australia; and
| | - Kulmira Nurgali
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia;
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McQuade RM, Carbone SE, Stojanovska V, Rahman A, Gwynne RM, Robinson AM, Goodman CA, Bornstein JC, Nurgali K. Role of oxidative stress in oxaliplatin-induced enteric neuropathy and colonic dysmotility in mice. Br J Pharmacol 2016; 173:3502-3521. [PMID: 27714760 PMCID: PMC5120153 DOI: 10.1111/bph.13646] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 09/18/2016] [Accepted: 09/19/2016] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND PURPOSE Oxaliplatin is a platinum-based chemotherapeutic drug used as a first-line therapy for colorectal cancer. However, its use is associated with severe gastrointestinal side-effects resulting in dose limitations and/or cessation of treatment. In this study, we tested whether oxidative stress, caused by chronic oxaliplatin treatment, induces enteric neuronal damage and colonic dysmotility. EXPERIMENTAL APPROACH Oxaliplatin (3 mg·kg-1 per day) was administered in vivo to Balb/c mice intraperitoneally three times a week. The distal colon was collected at day 14 of treatment. Immunohistochemistry was performed in wholemount preparations of submucosal and myenteric ganglia. Neuromuscular transmission was studied by intracellular electrophysiology. Circular muscle tone was studied by force transducers. Colon propulsive activity studied in organ bath experiments and faeces were collected to measure water content. KEY RESULTS Chronic in vivo oxaliplatin treatment resulted in increased formation of reactive oxygen species (O2 -), nitration of proteins, mitochondrial membrane depolarisation resulting in the release of cytochrome c, loss of neurons, increased inducible NOS expression and apoptosis in both the submucosal and myenteric plexuses of the colon. Oxaliplatin treatment enhanced NO-mediated inhibitory junction potentials and altered the response of circular muscles to the NO donor, sodium nitroprusside. It also reduced the frequency of colonic migrating motor complexes and decreased circular muscle tone, effects reversed by the NO synthase inhibitor, Nω-Nitro-L-arginine. CONCLUSION AND IMPLICATIONS Our study is the first to provide evidence that oxidative stress is a key player in enteric neuropathy and colonic dysmotility leading to symptoms of chronic constipation observed in oxaliplatin-treated mice.
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Affiliation(s)
- Rachel M McQuade
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Australia
| | - Simona E Carbone
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Australia
| | - Vanesa Stojanovska
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Australia
| | - Ahmed Rahman
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Australia
| | - Rachel M Gwynne
- Department of Physiology, Melbourne University, Melbourne, Australia
| | - Ainsley M Robinson
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Australia
| | - Craig A Goodman
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Australia
| | - Joel C Bornstein
- Department of Physiology, Melbourne University, Melbourne, Australia
| | - Kulmira Nurgali
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Australia
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Carbone SE, Jovanovska V, Brookes SJH, Nurgali K. Electrophysiological and morphological changes in colonic myenteric neurons from chemotherapy-treated patients: a pilot study. Neurogastroenterol Motil 2016; 28:975-84. [PMID: 26909894 PMCID: PMC5215581 DOI: 10.1111/nmo.12795] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/14/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Patients receiving anticancer chemotherapy experience a multitude of gastrointestinal side-effects. However, the causes of these symptoms are uncertain and whether these therapeutics directly affect the enteric nervous system is unknown. Our aim was to determine whether the function and morphology of myenteric neurons are altered in specimens of the colon from chemotherapy-treated patients. METHODS Colon specimens were compared from chemotherapy-treated and non-treated patients following colorectal resections for removal of carcinoma. Intracellular electrophysiological recordings from myenteric neurons and immunohistochemistry were performed in whole mount preparations. KEY RESULTS Myenteric S neurons from chemotherapy-treated patients were hyperexcitable; more action potentials (11.4 ± 9.4, p < 0.05) were fired in response to depolarising current pulses than in non-treated patients (1.4 ± 0.5). The rheobase and the threshold to evoke action potentials were significantly lower for neurons from chemotherapy-treated patients compared to neurons from non-treated patients (p < 0.01). Fast excitatory postsynaptic potential reversal potential was more positive in neurons from chemotherapy-treated patients (p < 0.05). An increase in the number of neurons with translocation of Hu protein from the cytoplasm to the nucleus was observed in specimens from chemotherapy-treated patients (103 ± 25 neurons/mm(2) , 37.2 ± 7.0%, n = 8) compared to non-treated (26 ± 5 neurons/mm(2) , 11.9 ± 2.7%, n = 12, p < 0.01). An increase in the soma size of neuronal nitric oxide synthase-immunoreactive neurons was also observed in these specimens. CONCLUSIONS & INFERENCES This is the first study suggesting functional and structural changes in human myenteric neurons in specimens of colon from patients receiving anticancer chemotherapy. These changes may contribute to the causation of gastrointestinal symptoms experienced by chemotherapy-treated patients.
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Affiliation(s)
- S. E. Carbone
- Centre for Chronic DiseaseCollege of Health and BiomedicineVictoria UniversityMelbourneVICAustralia
| | - V. Jovanovska
- Centre for Chronic DiseaseCollege of Health and BiomedicineVictoria UniversityMelbourneVICAustralia
| | - S. J. H. Brookes
- Discipline of Human Physiology and Centre for NeuroscienceFlinders UniversityAdelaideSAAustralia
| | - K. Nurgali
- Centre for Chronic DiseaseCollege of Health and BiomedicineVictoria UniversityMelbourneVICAustralia
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Humenick A, Chen BN, Wiklendt L, Spencer NJ, Zagorodnyuk VP, Dinning PG, Costa M, Brookes SJH. Activation of intestinal spinal afferent endings by changes in intra-mesenteric arterial pressure. J Physiol 2015; 593:3693-709. [PMID: 26010893 DOI: 10.1113/jp270378] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 05/18/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS A major class of mechano-nociceptors to the intestine have mechanotransduction sites on extramural and intramural arteries and arterioles ('vascular afferents'). These sensory neurons can be activated by compression or axial stretch of vessels. Using isolated preparations we showed that increasing intra-arterial pressure, within the physiological range, activated mechano-nociceptors on vessels in intact mesenteric arcades, but not in isolated arteries. This suggests that distortion of the branching vascular tree is the mechanical adequate stimulus for these sensory neurons, rather than simple distension. The same rises in pressure also activated intestinal peristalsis in a partially capsaicin-sensitive manner indicating that pressure-sensitive vascular afferents influence enteric circuits. The results identify the mechanical adequate stimulus for a major class of mechano-nociceptors with endings on blood vessels supplying the gut wall; these afferents have similar endings to ones supplying other viscera, striated muscle and dural vessels. ABSTRACT Spinal sensory neurons innervate many large blood vessels throughout the body. Their activation causes the hallmarks of neurogenic inflammation: vasodilatation through the release of the neuropeptide calcitonin gene-related peptide and plasma extravasation via tachykinins. The same vasodilator afferent neurons show mechanical sensitivity, responding to crushing, compression or axial stretch of blood vessels - responses which activate pain pathways and which can be modified by cell damage and inflammation. In the present study, we tested whether spinal afferent axons ending on branching mesenteric arteries ('vascular afferents') are sensitive to increased intravascular pressure. From a holding pressure of 5 mmHg, distension to 20, 40, 60 or 80 mmHg caused graded, slowly adapting increases in firing of vascular afferents. Many of the same afferent units showed responses to axial stretch, which summed with responses evoked by raised pressure. Many vascular afferents were also sensitive to raised temperature, capsaicin and/or local compression with von Frey hairs. However, responses to raised pressure in single, isolated vessels were negligible, suggesting that the adequate stimulus is distortion of the arterial arcade rather than distension per se. Increasing arterial pressure often triggered peristaltic contractions in the neighbouring segment of intestine, an effect that was mimicked by acute exposure to capsaicin (1 μm) and which was reduced after desensitisation to capsaicin. These results indicate that sensory fibres with perivascular endings are sensitive to pressure-induced distortion of branched arteries, in addition to compression and axial stretch, and that they contribute functional inputs to enteric motor circuits.
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Affiliation(s)
- A Humenick
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, South Australia
| | - B N Chen
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, South Australia
| | - L Wiklendt
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, South Australia
| | - N J Spencer
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, South Australia
| | - V P Zagorodnyuk
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, South Australia
| | - P G Dinning
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, South Australia
| | - M Costa
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, South Australia
| | - S J H Brookes
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, South Australia
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Effect of da-cheng-qi decoction on the repair of the injured enteric nerve-interstitial cells of cajal-smooth muscle cells network in multiple organ dysfunction syndrome. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:596723. [PMID: 25477993 PMCID: PMC4247919 DOI: 10.1155/2014/596723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 10/18/2014] [Accepted: 10/21/2014] [Indexed: 01/22/2023]
Abstract
Wistar rats were randomly divided into control group, multiple organ dysfunction syndrome (MODS) group, and Da-Cheng-Qi decoction (DCQD) group. The network of enteric nerves-interstitial cells of Cajal- (ICC-) smooth muscle cells (SMC) in small intestine was observed using confocal laser scanning microscopy and transmission electron microscopy. The results showed that the numbers of cholinergic/nitriergic nerves, and the deep muscular plexus of ICC (ICC-DMP) and connexin43 (Cx43) in small intestine with MODS were significantly decreased. The network integrity of enteric nerves-ICC-SMC was disrupted. The ultrastructures of ICC-DMP, enteric nerves, and SMC were severely damaged. After treatment with DCQD, the damages were repaired and the network integrity of enteric nerves ICC-SMC was significantly recovered. In conclusion, the pathogenesis of gastrointestinal motility dysfunction in MODS in part may be due to the damages to enteric nerves-ICC-SMC network and gap junctions. The therapeutic mechanism of DCQD in part may be that it could repair the damages and maintain the integrity of enteric nerves ICC-SMC network.
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10
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Carbone SE, Jovanovska V, Nurgali K, Brookes SJH. Human enteric neurons: morphological, electrophysiological, and neurochemical identification. Neurogastroenterol Motil 2014; 26:1812-6. [PMID: 25293378 PMCID: PMC4265287 DOI: 10.1111/nmo.12453] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Accepted: 09/13/2014] [Indexed: 12/15/2022]
Abstract
BACKGROUND Access to tissue, difficulties with dissection, and poor visibility of enteric ganglia have hampered electrophysiological recordings of human enteric neurons. Here, we report a method to combine intracellular recording with simultaneous morphological identification of neurons in the intact myenteric plexus of human colon ex vivo. METHODS Specimens of human colon were dissected into flat-sheet preparations with the myenteric plexus exposed. Myenteric neurons were impaled with conventional microelectrodes containing 5% 5,6-carboxyfluorescein in 20 mM Tris buffer and 1 M KCl. KEY RESULTS Electrophysiological recordings identified myenteric neurons with S and AH type properties (n = 13, N = 7) which were dye filled and classified during the recording as Dogiel type I (n = 10), Dogiel type II (n = 2), or filamentous (n = 1) cells. This classification was confirmed after fixation, in combination with immunohistochemical characterization. CONCLUSIONS & INFERENCES This method allows electrophysiological characterization with simultaneous identification of morphology. It can be used to identify recorded cells immediately after impalement and greatly facilitates recordings of human myenteric neurons in freshly dissected specimens of tissue. It can also be combined with immunohistochemical labeling of recorded cells.
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Affiliation(s)
- S E Carbone
- College of Health and Biomedicine, Western Centre for Health, Research and Education, Victoria UniversitySt Albans, VIC, Australia
| | - V Jovanovska
- College of Health and Biomedicine, Western Centre for Health, Research and Education, Victoria UniversitySt Albans, VIC, Australia
| | - K Nurgali
- College of Health and Biomedicine, Western Centre for Health, Research and Education, Victoria UniversitySt Albans, VIC, Australia
| | - S J H Brookes
- Discipline of Human Physiology, Centre for Neuroscience, Flinders UniversityAdelaide, SA, Australia
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Carbone SE, Wattchow DA, Spencer NJ, Hibberd TJ, Brookes SJH. Damage from dissection is associated with reduced neuro-musclar transmission and gap junction coupling between circular muscle cells of guinea pig ileum, in vitro. Front Physiol 2014; 5:319. [PMID: 25202280 PMCID: PMC4141521 DOI: 10.3389/fphys.2014.00319] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 08/04/2014] [Indexed: 11/13/2022] Open
Abstract
Excitatory and inhibitory junction potentials of circular smooth muscle cells in guinea pig ileum and colon are suppressed 30–90 min after setting up in vitro preparations. We have previously shown this “unresponsive” period is associated with a transient loss of dye coupling between smooth muscle cells, which subsequently recovers over the ensuing 30–90 min; junction potentials recover in parallel with dye coupling (Carbone et al., 2012). Here, we investigated which components of dissection trigger the initial loss of coupling. Intracellular recordings were made from circular muscle cells of guinea pig ileum with micropipettes containing 5% carboxyfluorescein. After allowing 90–120 min for junction potentials to reach full amplitude, we re-cut all 4 edges of the preparation more than 1 mm from the recording sites. This caused a reduction in the amplitude of IJPs from 17.2 ± 0.7 mV to 9.5 ± 1.5 mV (P < 0.001, n = 12) and a significant reduction in dye coupling. Both recovered within 60 min. We repeated this experiment (n = 4), recording both 1 and 4 mm from the cut edge: both sites were equally affected by re-cutting the sides of the preparation. Equilibrated preparations were stretched to 150% of their original length, this had no significant effect on junction potentials or dye coupling. Setting up preparations in low calcium solution did not prevent the initial suppression of IJPs and dye coupling. Application of 3 μM indomethacin (n = 3), 10 μM ketotifen (n = 4) or 10 μM forskolin during dissection did not prevent the suppression of IJPs and dye coupling. If dissection damage was reduced, by leaving the mucosa and submucosa attached to the circular muscle, IJPs showed less initial suppression than in preparations where the layers were dissected off. We conclude that physical damage to the gut wall triggers loss of gap junction coupling and neuromuscular transmission, this is not due to stretch, influx of calcium ions, release of prostaglandins or mast cell degranulation. The mechanisms underlying this potent effect remain to be determined.
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Affiliation(s)
- Simona E Carbone
- Centre for Chronic Disease Prevention and Management, Enteric Neuropathy Laboratory, College of Health and Biomedicine, Victoria University Melbourne, VIC, Australia
| | - David A Wattchow
- Neurogastroenterology Laboratory, Surgery, Discipline of Human Physiology and Centre for Neuroscience, Flinders Medical Science and Technology, Flinders University Adelaide, SA, Australia
| | - Nick J Spencer
- Discipline of Surgery and Centre for Neuroscience, Flinders University Adelaide, SA, Australia
| | - Timothy J Hibberd
- Discipline of Surgery and Centre for Neuroscience, Flinders University Adelaide, SA, Australia
| | - Simon J H Brookes
- Discipline of Surgery and Centre for Neuroscience, Flinders University Adelaide, SA, Australia
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Carbone SE, Dinning PG, Costa M, Spencer NJ, Brookes SJH, Wattchow DA. Ascending excitatory neural pathways modulate slow phasic myogenic contractions in the isolated human colon. Neurogastroenterol Motil 2013; 25:670-6. [PMID: 23634776 DOI: 10.1111/nmo.12129] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 03/16/2013] [Indexed: 01/11/2023]
Abstract
BACKGROUND In animal models, enteric reflex pathways have potent effects on motor activity; their roles have been much less extensively studied in human gut. The aim of this study was to determine if ascending excitatory interneuronal pathways can modulate spontaneous phasic contractions in isolated preparations of human colonic circular muscle. METHODS Human colonic preparations were cut into T shapes, with vertical bar of the 'T' pharmacologically isolated. Electrical stimulation and the nicotinic agonist, 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP), were applied to the isolated region and circular muscle contractile activity was measured from the cross-bar of the T, more than 10 mm orally from the region of stimulation. KEY RESULTS The predominant form of spontaneous muscle activity consisted of tetrodotoxin-resistant, large amplitude, slow phasic contractions (SPCs), occurring at average intervals of 124 ± 68 s. Addition of a high concentration of hexamethonium (1 mmol L(-1)) to the superfusing solution significantly increased the interval between SPCs to 278.1 ± 138.3 s (P < 0.005). Focal electrical stimulation more than 10 mm aboral to the muscle recording site advanced the onset of the next SPC, and this effect persisted in hexamethonium. However, the effect of electrical stimulation was blocked by tetrodotoxin (TTX, 1 μmol L(-1)). Application of the nicotinic agonist DMPP (1 mmol L(-1)) to the aboral chamber often stimulated a premature SPC (n = 4). CONCLUSIONS & INFERENCES The major form of spontaneous contractility in preparations of human colonic circular muscle is SPCs, which are myogenic in origin. Activation of ascending excitatory neural pathways, which involve nicotinic receptors, can modulate the timing of SPCs and thus influence human colonic motility.
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Affiliation(s)
- S E Carbone
- Discipline of Human Physiology, Flinders Medical Science and Technology, Flinders University, Adelaide, South Australia, Australia
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