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Lee EEL, O'Malley-Krohn I, Edsinger E, Wu S, Malamy J. Epithelial wound healing in Clytia hemisphaerica provides insights into extracellular ATP signaling mechanisms and P2XR evolution. Sci Rep 2023; 13:18819. [PMID: 37914720 PMCID: PMC10620158 DOI: 10.1038/s41598-023-45424-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 10/19/2023] [Indexed: 11/03/2023] Open
Abstract
Epithelial wound healing involves the collective responses of many cells, including those at the wound margin (marginal cells) and those that lack direct contact with the wound (submarginal cells). How these responses are induced and coordinated to produce rapid, efficient wound healing remains poorly understood. Extracellular ATP (eATP) is implicated as a signal in epithelial wound healing in vertebrates. However, the role of eATP in wound healing in vivo and the cellular responses to eATP are unclear. Almost nothing is known about eATP signaling in non-bilaterian metazoans (Cnidaria, Ctenophora, Placozoa, and Porifera). Here, we show that eATP promotes closure of epithelial wounds in vivo in the cnidarian Clytia hemisphaerica (Clytia) indicating that eATP signaling is an evolutionarily ancient strategy in wound healing. Furthermore, eATP increases F-actin accumulation at the edges of submarginal cells. In Clytia, this indicates eATP is involved in coordinating cellular responses during wound healing, acting in part by promoting actin remodeling in cells at a distance from the wound. We also present evidence that eATP activates a cation channel in Clytia epithelial cells. This implies that the eATP signal is transduced through a P2X receptor (P2XR). Phylogenetic analyses identified four Clytia P2XR homologs and revealed two deeply divergent major branches in P2XR evolution, necessitating revision of current models. Interestingly, simple organisms such as cellular slime mold appear exclusively on one branch, bilaterians are found exclusively on the other, and many non-bilaterian metazoans, including Clytia, have P2XR sequences from both branches. Together, these results re-draw the P2XR evolutionary tree, provide new insights into the origin of eATP signaling in wound healing, and demonstrate that the cytoskeleton of submarginal cells is a target of eATP signaling.
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Affiliation(s)
- Elizabeth E L Lee
- Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA
| | - Isabel O'Malley-Krohn
- Biological Sciences Collegiate Division, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA
| | - Eric Edsinger
- Whitney Laboratory for Marine Biosciences, University of Florida, 9505 N Ocean Shore Blvd, St. Augustine, FL, 32080, USA
| | - Stephanie Wu
- Biological Sciences Collegiate Division, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA
| | - Jocelyn Malamy
- Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA.
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An Q, Yue G, Yang X, Lou J, Shan W, Ding J, Jin Z, Hu Y, Du Q, Liao Q, Xie R, Xu J. Pathophysiological Role of Purinergic P2X Receptors in Digestive System Diseases. Front Physiol 2022; 12:781069. [PMID: 35002763 PMCID: PMC8740087 DOI: 10.3389/fphys.2021.781069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/01/2021] [Indexed: 11/16/2022] Open
Abstract
P2X receptors (P2XRs) are trimeric, non-selective cation channels activated by extracellular ATP and widely distributed in the digestive system. P2XRs have an important role in the physiological function of the digestive system, such as neurotransmission, ion transports, proliferation and apoptosis, muscle contraction, and relaxation. P2XRs can be involved in pain mechanisms both centrally and in the periphery and confirmed the association of P2XRs with visceral pain. In the periphery, ATP can be released as a result of tissue injury, visceral distension, or sympathetic activation and can excite nociceptive primary afferents by acting at homomeric P2X(3)R or heteromeric P2X(2/3)R. Thus, peripheral P2XRs, and homomeric P2X(3) and/or heteromeric P2X(2/3)R in particular, constitute attractive targets for analgesic drugs. Recently studies have shown that P2XRs have made significant advances in inflammation and cancer. P2X7R mediates NLRP3 inflammasome activation, cytokine and chemokine release, T lymphocyte survival and differentiation, transcription factor activation, and cell death. The P2X7R is a potent stimulant of inflammation and immunity and a promoter of cancer cell growth. This makes P2X7R an appealing target for anti-inflammatory and anti-cancer therapy. It is believed that with the further study of P2XRs and its subtypes, P2XRs and its specific antagonists will be expected to be widely used in the treatment of human digestive diseases in the future.
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Affiliation(s)
- Qimin An
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Gengyu Yue
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Xiaoxu Yang
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Jun Lou
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Weixi Shan
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Jianhong Ding
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Zhe Jin
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Yanxia Hu
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Qian Du
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Qiushi Liao
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Rui Xie
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Jingyu Xu
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
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3
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Liu PW, Yue MX, Zhou R, Niu J, Huang DJ, Xu T, Luo P, Liu XH, Zeng JW. P2Y 12 and P2Y 13 receptors involved in ADPβs induced the release of IL-1β, IL-6 and TNF-α from cultured dorsal horn microglia. J Pain Res 2017; 10:1755-1767. [PMID: 28794655 PMCID: PMC5536317 DOI: 10.2147/jpr.s137131] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Objective P2 receptors have been implicated in the release of neurotransmitter and pro-inflammatory cytokines due to their response to neuroexcitatory substances in the microglia. Dorsal horn P2Y12 and P2Y13 receptors are involved in the development of pain behavior induced by peripheral nerve injury. However, it is not known whether P2Y12 and P2Y13 receptors activation is associated with the expression and the release of interleukin-1B (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) in cultured dorsal spinal cord microglia. For this reason, we examined the effects of ADPβs (ADP analog) on the expression and the release of IL-1β, IL-6, and TNF-α. Methods and results In this study, we observed the effect of P2Y receptor agonist ADPβs on the expression and release of IL-1β, IL-6 and TNF-α by using real-time fluorescence quantitative polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). ADPβs induced the increased expression of Iba-1, IL-1β, IL-6 and TNF-α at the level of messenger RNA (mRNA). ADPβs-evoked increase in Iba-1, IL-1β, IL-6 and TNF-α mRNA expression was inhibited only partially by P2Y12 receptor antagonist MRS2395 or P2Y13 receptor antagonist MRS2211, respectively. Similarly, ADPβs-evoked release of IL-1β, IL-6 and TNF-α was inhibited only partially by MRS2395 or MRS2211. Furthermore, ADPβs-evoked increased expression of Iba-1, IL-1β, IL-6 and TNF-α mRNA, and release of IL-1β, IL-6 and TNF-α were nearly all blocked after co-administration of MRS2395 plus MRS2179. Further evidence indicated that P2Y12 and P2Y13 receptor-evoked increased gene expression of IL-1β, IL-6 and TNF-α were inhibited by Y-27632 (ROCK inhibitor), SB203580 (P38MAPK inhibitor) and PDTC (NF-κb inhibitor), respectively. Subsequently, P2Y12 and P2Y13 receptor-evoked release of IL-1β, IL-6 and TNF-α, were also inhibited by Y-27632, SB203580 and PDTC, respectively. Conclusion These observations suggest that P2Y12 and P2Y13 receptor-evoked gene expression and release of IL-1β, IL-6 and TNF-α are associated with ROCK/P38MAPK/NF-κb signaling pathway.
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Affiliation(s)
- Pei-Wen Liu
- Department of Physiology, Zunyi Medical College, Guizhou, China
| | - Ming-Xia Yue
- Department of Physiology, Zunyi Medical College, Guizhou, China
| | - Rui Zhou
- Department of Physiology, Zunyi Medical College, Guizhou, China
| | - Juan Niu
- Department of Physiology, Zunyi Medical College, Guizhou, China
| | - Du-Juan Huang
- Department of Physiology, Zunyi Medical College, Guizhou, China
| | - Tao Xu
- Department of Physiology, Zunyi Medical College, Guizhou, China
| | - Pei Luo
- Department of Physiology, Zunyi Medical College, Guizhou, China
| | - Xiao-Hong Liu
- Department of Physiology, Zunyi Medical College, Guizhou, China
| | - Jun-Wei Zeng
- Department of Physiology, Zunyi Medical College, Guizhou, China
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Min CH, Min YS, Lee SJ, Sohn UD. The comparative effects of aminoglycoside antibiotics and muscle relaxants on electrical field stimulation response in rat bladder smooth muscle. Arch Pharm Res 2016; 39:863-70. [PMID: 27260628 DOI: 10.1007/s12272-016-0765-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/24/2016] [Indexed: 10/21/2022]
Abstract
It has been reported that several aminoglycoside antibiotics have a potential of prolonging the action of non-depolarizing muscle relaxants by drug interactions acting pre-synaptically to inhibit acetylcholine release, but antibiotics itself also have a strong effect on relaxing the smooth muscle. In this study, four antibiotics of aminoglycosides such as gentamicin, streptomycin, kanamycin and neomycin were compared with skeletal muscle relaxants baclofen, tubocurarine, pancuronium and succinylcholine, and a smooth muscle relaxant, papaverine. The muscle strips isolated from the rat bladder were stimulated with pulse trains of 40 V in amplitude and 10 s in duration, with pulse duration of 1 ms at the frequency of 1-8 Hz, at 1, 2, 4, 6, 8 Hz respectively. To test the effect of four antibiotics on bladder smooth muscle relaxation, each of them was treated cumulatively from 1 μM to 0.1 mM with an interval of 5 min. Among the four antibiotics, gentamicin and neomycin inhibited the EFS response. The skeletal muscle relaxants (baclofen, tubocurarine, pancuronium and succinylcholine) and inhibitory neurotransmitters (GABA and glycine) did not show any significant effect. However, papaverine, had a significant effect in the relaxation of the smooth muscle. It was suggested that the aminoglycoside antibiotics have inhibitory effect on the bladder smooth muscle.
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Affiliation(s)
- Chang Ho Min
- College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea
| | - Young Sil Min
- Department of Medical Plant Science, Jung Won University, Chungbuk, Republic of Korea
| | - Sang Joon Lee
- College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea.
| | - Uy Dong Sohn
- College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea.
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5
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Wan HX, Hu JH, Xie R, Yang SM, Dong H. Important roles of P2Y receptors in the inflammation and cancer of digestive system. Oncotarget 2016; 7:28736-47. [PMID: 26908460 PMCID: PMC5053759 DOI: 10.18632/oncotarget.7518] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/05/2016] [Indexed: 02/03/2023] Open
Abstract
Purinergic signaling is important for many biological processes in humans. Purinoceptors P2Y are widely distributed in human digestive system and different subtypes of P2Y receptors mediate different physiological functions from metabolism, proliferation, differentiation to apoptosis etc. The P2Y receptors are essential in many gastrointestinal functions and also involve in the occurrence of some digestive diseases. Since different subtypes of P2Y receptors are present on the same cell of digestive organs, varying subtypes of P2Y receptors may have opposite or synergetic functions on the same cell. Recently, growing lines of evidence strongly suggest the involvement of P2Y receptors in the pathogenesis of several digestive diseases. In this review, we will focus on their important roles in the development of digestive inflammation and cancer. We anticipate that as the special subtypes of P2Y receptors are studied in depth, specific modulators for them will have good potentials to become promising new drugs to treat human digestive diseases in the near future.
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Affiliation(s)
- Han-Xing Wan
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
| | - Jian-Hong Hu
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
| | - Rei Xie
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
| | - Shi-Ming Yang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
| | - Hui Dong
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of California, San Diego, California, USA
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6
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Kwon TH, Jung H, Cho EJ, Jeong JH, Sohn UD. The Signaling Mechanism of Contraction Induced by ATP and UTP in Feline Esophageal Smooth Muscle Cells. Mol Cells 2015; 38:616-23. [PMID: 26013385 PMCID: PMC4507027 DOI: 10.14348/molcells.2015.2357] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 04/07/2015] [Accepted: 04/16/2015] [Indexed: 11/29/2022] Open
Abstract
P2 receptors are membrane-bound receptors for extracellular nucleotides such as ATP and UTP. P2 receptors have been classified as ligand-gated ion channels or P2X receptors and G protein-coupled P2Y receptors. Recently, purinergic signaling has begun to attract attention as a potential therapeutic target for a variety of diseases especially associated with gastroenterology. This study determined the ATP and UTP-induced receptor signaling mechanism in feline esophageal contraction. Contraction of dispersed feline esophageal smooth muscle cells was measured by scanning micrometry. Phosphorylation of MLC20 was determined by western blot analysis. ATP and UTP elicited maximum esophageal contraction at 30 s and 10 μM concentration. Contraction of dispersed cells treated with 10 μM ATP was inhibited by nifedipine. However, contraction induced by 0.1 μM ATP, 0.1 μM UTP and 10 μM UTP was decreased by U73122, chelerythrine, ML-9, PTX and GDPβS. Contraction induced by 0.1 μM ATP and UTP was inhibited by Gαi3 or Gαq antibodies and by PLCβ1 or PLCβ3 antibodies. Phosphorylated MLC20 was increased by ATP and UTP treatment. In conclusion, esophageal contraction induced by ATP and UTP was preferentially mediated by P2Y receptors coupled to Gαi3 and G q proteins, which activate PLCβ1 and PLCβ3. Subsequently, increased intracellular Ca(2+) and activated PKC triggered stimulation of MLC kinase and inhibition of MLC phosphatase. Finally, increased pMLC20 generated esophageal contraction.
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Affiliation(s)
- Tae Hoon Kwon
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 156-756,
Korea
| | - Hyunwoo Jung
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 156-756,
Korea
| | - Eun Jeong Cho
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 156-756,
Korea
| | - Ji Hoon Jeong
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul 156-756,
Korea
| | - Uy Dong Sohn
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 156-756,
Korea
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Antonioli L, Giron MC, Colucci R, Pellegrini C, Sacco D, Caputi V, Orso G, Tuccori M, Scarpignato C, Blandizzi C, Fornai M. Involvement of the P2X7 purinergic receptor in colonic motor dysfunction associated with bowel inflammation in rats. PLoS One 2014; 9:e116253. [PMID: 25549098 PMCID: PMC4280204 DOI: 10.1371/journal.pone.0116253] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 12/06/2014] [Indexed: 12/31/2022] Open
Abstract
Background and Purpose Recent evidence indicates an involvement of P2X7 purinergic receptor (P2X7R) in the fine tuning of immune functions, as well as in driving enteric neuron apoptosis under intestinal inflammation. However, the participation of this receptor in the regulation of enteric neuromuscular functions remains undetermined. This study was aimed at investigating the role of P2X7Rs in the control of colonic motility in experimental colitis. Experimental Approach Colitis was induced in rats by 2,4-dinitrobenzenesulfonic acid. P2X7R distribution was examined by immunofluorescence analysis. The effects of A804598 (selective P2X7R antagonist) and BzATP (P2X7R agonist) were tested on contractions of longitudinal smooth muscle evoked by electrical stimulation or by carbachol in the presence of tetrodotoxin. Key Results P2X7Rs were predominantly located in myenteric neurons, but, in the presence of colitis, their expression increased in the neuromuscular layer. In normal preparations, A804598 elicited a negligible increase in electrically induced contractions, while a significant enhancement was recorded in inflamed tissues. In the presence of Nω-propyl-L-arginine (NPA, neuronal nitric oxide synthase inhibitor) the A804598 effects were lost. P2X7R stimulation with BzATP did not significantly affect electrical-induced contractions in normal colon, while a marked reduction was recorded under inflammation. The inhibitory effect of BzATP was antagonized by A804598, and it was also markedly blunted by NPA. Both P2X7R ligands did not affect carbachol-induced contractions. Conclusions and Implications The purinergic system contributes to functional neuromuscular changes associated with bowel inflammation via P2X7Rs, which modulate the activity of excitatory cholinergic nerves through a facilitatory control on inhibitory nitrergic pathways.
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Affiliation(s)
- Luca Antonioli
- Division of Pharmacology and Chemotherapy, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Maria Cecilia Giron
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Rocchina Colucci
- Division of Pharmacology and Chemotherapy, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- * E-mail:
| | - Carolina Pellegrini
- Division of Pharmacology and Chemotherapy, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Deborah Sacco
- Division of Pharmacology and Chemotherapy, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Valentina Caputi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Genny Orso
- Scientific Institute IRCCS Eugenio Medea, Conegliano, Treviso, Italy
| | - Marco Tuccori
- Division of Pharmacology and Chemotherapy, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Corrado Blandizzi
- Division of Pharmacology and Chemotherapy, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Matteo Fornai
- Division of Pharmacology and Chemotherapy, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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Lecea B, Gallego D, Farré R, Clavé P. Origin and modulation of circular smooth muscle layer contractions in the porcine esophagus. Neurogastroenterol Motil 2012; 24:779-89, e355. [PMID: 22632463 DOI: 10.1111/j.1365-2982.2012.01936.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
BACKGROUND The origin and modulation mechanisms controlling timing and amplitude of esophageal body peristalsis are not fully understood. We aimed to characterize the neurotransmitters involved in the origin and modulation of circular smooth muscle esophageal body (EB) contractions. METHODS Responses of porcine EB strips to electrical stimulation of motor neurons (MNs) were assessed in organ baths and with microelectrodes. The effect of antagonists of inhibitory (L-NAME 1 mmol L(-1) , MRS2179 10 μmol L(-1) ) and excitatory neurotransmitters (atropine 1 μmol L(-1) ; SR140333 1 μmol L(-1) -NK(1) ra-, GR94800 1 μmol L(-1) -NK(2) ra-) and of ganglionic neurotransmitters (hexamethonium 100 μmol L(-1) , ondansetron 1 μmol L(-1) , NF279 10 μmol L(-1) ) were characterized. KEY RESULTS Electrical field stimulation (EFS) induced a frequency-dependent off-contraction (16.8 ± 0.8 g) following a latency period. Latency was significantly reduced by L-NAME (-66.1 ± 4.1%) and MRS2179 (-25.9 ± 5.6%), and strongly increased by atropine (+36.8 ± 5.8%). Amplitude was reduced by L-NAME (-69.9 ± 10.4%), MRS2179 (-34.1 ± 6.0%), atropine (-42.3 ± 4.7%), hexamethonium (-18.9 ± 3.3%), NF279 (-20.7 ± 3.5%), ondansetron (-16.3 ± 3.2%), GR94800 (-28.0 ± 4.8%) SR140333 (-20.9 ± 7.1%), and α-chymotrypsin (-31.3 ± 7.0%). The EFS induced a monophasic nitrergic inhibitory junction potential. CONCLUSIONS & INFERENCES Our results suggest that timing (latency) and amplitude of esophageal contractions are determined by a balance of complex interactions between excitatory and inhibitory MNs. Latency depends on the activation of inhibitory MNs releasing NO and a minor purinergic contribution through P2Y(1) receptors, and excitatory MNs releasing ACh. Amplitude depends on a major contribution of excitatory MNs releasing ACh and tachykinins, and also on inhibitory MNs releasing NO, ATP or related purines, and peptidergic neurotransmitters acting as strong modulators of the excitatory neuroeffector transmission.
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Affiliation(s)
- B Lecea
- Department of Surgery, Hospital de Mataró, Universitat Autònoma de Barcelona, Barcelona, Spain
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