1
|
Shi J, Tan X, Feng G, Zhuo Y, Jiang Z, Banda S, Wang L, Zheng W, Chen L, Yu D, Guo C. Research advances in drug therapy of endometriosis. Front Pharmacol 2023; 14:1199010. [PMID: 37416064 PMCID: PMC10320007 DOI: 10.3389/fphar.2023.1199010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 06/13/2023] [Indexed: 07/08/2023] Open
Abstract
Endometriosis is one of the most common benign gynecological disorders in reproductive-aged women. The major symptoms are chronic pelvic pain and infertility. Despite its profound impact on women's health and quality of life, its pathogenesis has not been fully elucidated, it cannot be cured and the long-term use of drugs yields severe side effects and hinders fertility. This review aims to present the advances in pathogenesis and the newly reported lead compounds and drugs managing endometriosis. This paper investigated Genetic changes, estrogen-dependent inflammation induction, progesterone resistance, imbalance in proliferation and apoptosis, angiogenesis, lymphangiogenesis and neurogenesis, and tissue remodeling in its pathogenesis; and explored the pharmacological mechanisms, constitutive relationships, and application prospects of each compound in the text. To date, Resveratrol, Bay1316957, and bardoxifene were effective against lesions and pain in controlled animal studies. In clinical trials, Quinagolide showed no statistical difference with the placebo group; the results of phase II clinical trial of the IL-33 antibody have not been announced yet; clinical trial stage III of vilaprisan was suspended due to drug toxicity. Elagolix was approved for the treatment of endometriosis-related pain, but clinical studies of Elagolix for the pretreatment of patients with endometriosis to before In vitro fertilization treatment have not been fulfilled. The results of a clinical study of Linzagolix in patients with moderate to severe endometriosis-related pain have not been disclosed yet. Letrozole improved the fertility of patients with mild endometriosis. For endometriosis patients with infertility, oral GnRH antagonists and aromatase inhibitors are promising drugs, especially Elagolix and Letrozole.
Collapse
Affiliation(s)
- Jianyou Shi
- Department of Pharmacy, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Xin Tan
- Department of Pharmacy, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Guimei Feng
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Yuan Zhuo
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Zhongliang Jiang
- Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Srikanth Banda
- Department of Chemistry and Biochemisty, Florida International University, Miami, FL, United States
| | - Lin Wang
- College of Food and Bioengineering, Xihua University, Chengdu, China
| | - Wei Zheng
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Lu Chen
- Department of Pharmacy, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Dongke Yu
- Department of Pharmacy, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Chun Guo
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| |
Collapse
|
2
|
Neto AC, Santos-Pereira M, Abreu-Mendes P, Neves D, Almeida H, Cruz F, Charrua A. The Unmet Needs for Studying Chronic Pelvic/Visceral Pain Using Animal Models. Biomedicines 2023; 11:biomedicines11030696. [PMID: 36979674 PMCID: PMC10045296 DOI: 10.3390/biomedicines11030696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/13/2023] [Accepted: 02/16/2023] [Indexed: 03/03/2023] Open
Abstract
The different definitions of chronic pelvic/visceral pain used by international societies have changed over the years. These differences have a great impact on the way researchers study chronic pelvic/visceral pain. Recently, the role of systemic changes, including the role of the central nervous system, in the perpetuation and chronification of pelvic/visceral pain has gained weight. Consequently, researchers are using animal models that resemble those systemic changes rather than using models that are organ- or tissue-specific. In this review, we discuss the advantages and disadvantages of using bladder-centric and systemic models, enumerating some of the central nervous system changes and pain-related behaviors occurring in each model. We also present some drawbacks when using animal models and pain-related behavior tests and raise questions about possible, yet to be demonstrated, investigator-related bias. We also suggest new approaches to study chronic pelvic/visceral pain by refining existing animal models or using new ones.
Collapse
Affiliation(s)
- Ana Catarina Neto
- Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal
| | - Mariana Santos-Pereira
- Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal
| | - Pedro Abreu-Mendes
- I3S—Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal
- Department of Urology, Centro Hospitalar de São João, 4200-319 Porto, Portugal
- Physiology and Surgery Department, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal
| | - Delminda Neves
- Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal
| | - Henrique Almeida
- Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal
- Ginecologia-Obstetrícia, Hospital-CUF Porto, 4100-180 Porto, Portugal
| | - Francisco Cruz
- I3S—Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal
- Department of Urology, Centro Hospitalar de São João, 4200-319 Porto, Portugal
- Physiology and Surgery Department, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal
| | - Ana Charrua
- Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal
- Correspondence:
| |
Collapse
|
3
|
Tejada MA, Antunez C, Nunez-Badinez P, De Leo B, Saunders PT, Vincent K, Cano A, Nagel J, Gomez R. Rodent Animal Models of Endometriosis-Associated Pain: Unmet Needs and Resources Available for Improving Translational Research in Endometriosis. Int J Mol Sci 2023; 24. [PMID: 36768741 DOI: 10.3390/ijms24032422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/23/2023] [Accepted: 01/24/2023] [Indexed: 01/28/2023] Open
Abstract
Chronic pain induced by endometriosis is a maladaptive pain experienced by half of women with this disease. The lack of pharmacological treatments suitable for the long-term relief of endometriosis-associated pain, without an impact on fertility, remains an urgent unmet need. Progress has been slowed by the absence of a reproducible rodent endometriosis model that fully replicates human physiopathological characteristics, including pain symptoms. Although pain assessment in rodents is a complicated task requiring qualified researchers, the choice of the behavioral test is no less important, since selecting inappropriate tests can cause erroneous data. Pain is usually measured with reflex tests in which hypersensitivity is evaluated by applying a noxious stimulus, yet this ignores the associated emotional component that could be evaluated via non-reflex tests. We conducted a systematic review of endometriosis models used in rodents and the number of them that studied pain. The type of behavioral test used was also analyzed and classified according to reflex and non-reflex tests. Finally, we determined the most used reflex tests for the study of endometriosis-induced pain and the main non-reflex behavioral tests utilized in visceral pain that can be extrapolated to the study of endometriosis and complement traditional reflex tests.
Collapse
|
4
|
Werner S, Mesch S, Hillig RC, Ter Laak A, Klint J, Neagoe I, Laux-Biehlmann A, Dahllöf H, Bräuer N, Puetter V, Nubbemeyer R, Schulz S, Bairlein M, Zollner TM, Steinmeyer A. Discovery and Characterization of the Potent and Selective P2X4 Inhibitor N-[4-(3-Chlorophenoxy)-3-sulfamoylphenyl]-2-phenylacetamide (BAY-1797) and Structure-Guided Amelioration of Its CYP3A4 Induction Profile. J Med Chem 2019; 62:11194-11217. [PMID: 31746599 DOI: 10.1021/acs.jmedchem.9b01304] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The P2X4 receptor is a ligand-gated ion channel that is expressed on a variety of cell types, especially those involved in inflammatory and immune processes. High-throughput screening led to a new class of P2X4 inhibitors with substantial CYP 3A4 induction in human hepatocytes. A structure-guided optimization with respect to decreased pregnane X receptor (PXR) binding was started. It was found that the introduction of larger and more polar substituents on the ether linker led to less PXR binding while maintaining the P2X4 inhibitory potency. This translated into significantly reduced CYP 3A4 induction for compounds 71 and 73. Unfortunately, the in vivo pharmacokinetic (PK) profiles of these compounds were insufficient for the desired profile in humans. However, BAY-1797 (10) was identified and characterized as a potent and selective P2X4 antagonist. This compound is suitable for in vivo studies in rodents, and the anti-inflammatory and anti-nociceptive effects of BAY-1797 were demonstrated in a mouse complete Freund's adjuvant (CFA) inflammatory pain model.
Collapse
Affiliation(s)
- Stefan Werner
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Stefanie Mesch
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Roman C Hillig
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Antonius Ter Laak
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | | | | | | | - Henrik Dahllöf
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Nico Bräuer
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Vera Puetter
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | | | - Simone Schulz
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Michaela Bairlein
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Thomas M Zollner
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Andreas Steinmeyer
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| |
Collapse
|
5
|
Bäurle S, Nagel J, Peters O, Bräuer N, ter Laak A, Preusse C, Rottmann A, Heldmann D, Bothe U, Blume T, Zorn L, Walter D, Zollner TM, Steinmeyer A, Langer G. Identification of a Benzimidazolecarboxylic Acid Derivative (BAY 1316957) as a Potent and Selective Human Prostaglandin E2 Receptor Subtype 4 (hEP4-R) Antagonist for the Treatment of Endometriosis. J Med Chem 2019; 62:2541-2563. [DOI: 10.1021/acs.jmedchem.8b01862] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Stefan Bäurle
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Jens Nagel
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Olaf Peters
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Nico Bräuer
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Antonius ter Laak
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Cornelia Preusse
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Antje Rottmann
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Dieter Heldmann
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Ulrich Bothe
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Thorsten Blume
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Ludwig Zorn
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Daryl Walter
- Evotec (UK) Ltd., 112-114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Thomas M. Zollner
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Andreas Steinmeyer
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| | - Gernot Langer
- Bayer AG, Research & Development, Pharmaceuticals, Müllerstrasse 178, 13353 Berlin, Germany
| |
Collapse
|
6
|
Yamamoto M, Motomura E, Yanagisawa R, Hoang VAT, Mogi M, Mori T, Nakamura M, Takeya M, Eto K. Evaluation of neurobehavioral impairment in methylmercury-treated KK-Ay mice by dynamic weight-bearing test. J Appl Toxicol 2018; 39:221-230. [PMID: 30175511 DOI: 10.1002/jat.3710] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/21/2018] [Accepted: 07/11/2018] [Indexed: 12/22/2022]
Abstract
Methylmercury (MeHg) is known to cause neurobehavioral impairment in human and experimental animals. We previously reported that MeHg (5 mg Hg/kg) induced severe neurobehavioral dysfunction in 4-week-old KK-Ay mice, although it is difficult to evaluate quantitatively the neurobehavioral impairment in MeHg-treated KK-Ay mice because of their obesity. The aim of this study was to evaluate MeHg-induced neurobehavioral dysfunction in KK-Ay mice using the dynamic weight-bearing test, which analyzes the animal's weight distribution between the four limbs. Male 12-week-old KK-Ay mice were treated with MeHg (5 mg Hg/kg) three times per week for 5 weeks. Body weight loss began after approximately 2 weeks of MeHg treatment, and decreased significantly at 4 weeks. Seven of the nine MeHg-treated mice exhibited overt neurological symptoms such as ataxia and gait disturbance. The weight-bearing load was lower for the forelimb than for the hindlimb at baseline and until 1 week after MeHg treatment was initiated. In weeks 2-4, the dynamic weight-bearing loads on the forelimb and hindlimb were similar. The load on the forelimb exceeded the load on the hindlimb after 5 weeks of treatment. This finding indicates that the dynamic weight-bearing test is useful for semi-quantitative evaluation of neurobehavioral impairment in MeHg-treated rodents, and is less stressful for the animals. Infiltration of CD204-positive macrophages was observed in the sciatic nerve of MeHg-treated mice, suggesting that CD204 can serve as a useful marker of tissue injury in peripheral nerves and a possible target in regenerating peripheral nerves and controlling neuropathies.
Collapse
Affiliation(s)
- Megumi Yamamoto
- Integrated Physiology Section, Department of Basic Medical Science, National Institute for Minamata Disease, 4058-18 Hama, Minamata, Kumamoto, 867-0008, Japan
| | - Eriko Motomura
- Integrated Physiology Section, Department of Basic Medical Science, National Institute for Minamata Disease, 4058-18 Hama, Minamata, Kumamoto, 867-0008, Japan
| | - Rie Yanagisawa
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Van Anh Thi Hoang
- Integrated Physiology Section, Department of Basic Medical Science, National Institute for Minamata Disease, 4058-18 Hama, Minamata, Kumamoto, 867-0008, Japan.,Graduate School of Environmental and Symbiotic Science, Prefectural University of Kumamoto, 3-1-100 Tsukide, Higashi-ku, Kumamoto, 862-8502, Japan
| | - Masaki Mogi
- Department of Pharmacology, Ehime University Graduate School of Medicine, Ehime, 791-0295, Japan
| | - Tomohisa Mori
- Department of Pharmacology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, 142-8501, Japan
| | - Masaaki Nakamura
- Department of Clinical Medicine, National Institute for Minamata Disease, 4058-18 Hama, Minamata, Kumamoto, 867-0008, Japan
| | - Motohiro Takeya
- Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Komyo Eto
- Health and Nursing Facilities for the Aged, Jushindai, Shinwakai, 272 Ikurakitakata, Tamana, Kumamoto, 865-0041, Japan
| |
Collapse
|
7
|
Laux-Biehlmann A, Boyken J, Dahllöf H, Schmidt N, Zollner TM, Nagel J. Dynamic weight bearing as a non-reflexive method for the measurement of abdominal pain in mice. Eur J Pain 2015; 20:742-52. [PMID: 26684879 DOI: 10.1002/ejp.800] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND Chronic pelvic pain (CPP) is a high burden for patients and society. It affects 15-24% of women in reproductive age and is an area of high unmet medical need. CPP can be caused by a wide range of visceral diseases such as abdominal infections, gastrointestinal or gynaecological diseases like endometriosis. Despite the high medical need for this condition, pharmacological approaches are hampered by the limited number of available methods for the behavioural evaluation of pain in inflammation-driven animal models of pelvic pain. METHODS The dynamic weight bearing (DWB) system was used for the evaluation of spontaneous behaviour changes in the zymosan-induced peritonitis mouse model. Inflammatory mediator levels were evaluated in peritoneal lavage and their correlation with the behavioural endpoints was assessed. We evaluated the effect on behavioural endpoints of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib and the Nav 1.8 blocker A-803467. RESULTS The presence of a relief posture, characterized by a significantly increased weight distribution towards the front paws, was observed following intraperitoneal injection of zymosan. A positive correlation was detected between PGE2 levels in the peritoneal lavage and DWB endpoints. In addition, zymosan-induced weight bearing changes were reverted by celecoxib and A-803467. CONCLUSIONS This study described for the first time the use of DWB as a non-subjective and non-reflexive method for the evaluation of inflammatory-driven abdominal pain in a mouse model.
Collapse
Affiliation(s)
- A Laux-Biehlmann
- Global Drug Discovery, Global Therapeutic Research Groups, Gynecological Therapies, Bayer Healthcare, Berlin, Germany
| | - J Boyken
- Global Drug Discovery, Global Therapeutic Research Groups, Gynecological Therapies, Bayer Healthcare, Berlin, Germany
| | - H Dahllöf
- Global Drug Discovery, Global Therapeutic Research Groups, Gynecological Therapies, Bayer Healthcare, Berlin, Germany
| | - N Schmidt
- Global Drug Discovery, Global Therapeutic Research Groups, Gynecological Therapies, Bayer Healthcare, Berlin, Germany
| | - T M Zollner
- Global Drug Discovery, Global Therapeutic Research Groups, Gynecological Therapies, Bayer Healthcare, Berlin, Germany
| | - J Nagel
- Global Drug Discovery, Global Therapeutic Research Groups, Gynecological Therapies, Bayer Healthcare, Berlin, Germany
| |
Collapse
|
8
|
Xue B, Kasparek MS, Müller MH, Kreis ME. Modulation of intestinal afferent nerve sensitivity to inflammatory mediators following systemic endotoxin in mice. Neurogastroenterol Motil 2015; 27:550-8. [PMID: 25817056 DOI: 10.1111/nmo.12531] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 01/23/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND Endotoxin exposure may be followed by visceral hypersensitvity but potential mechanisms are not fully explored. We aimed to test the hypothesis that mast cells and the cyclooxygenase pathway (COX) mediate modulation of afferent nerve sensitivity following systemic endotoxin. METHODS C57Bl6 mice received endotoxin injection i.p. to induce systemic inflammation. Control animals received normal saline. Extracellular multi-unit afferent nerve discharge was recorded from jejunal mesenteric nerves in vitro. Afferent nerve response to 5-hydroxytryptamine (5-HT, 250 μmol/L), bradykinin (BK, 0.5 μmol/L), and to mechanical ramp distension of the intestinal lumen from 0 to 60 cmH2O were recorded 2 h following endotoxin administration. KEY RESULTS Following endotoxin administration peak afferent discharge to 5-HT and BK was increased compared to controls (p < 0.05). Pre-perfusion with the mast cell stabilizer Doxantrazole (10(-4) M), or the cyclooxygenase inhibitor Naproxen inhibited the increased response to 5-HT and BK (p < 0.05 vs endotoxin pretreatment). Mechanosensitivity during luminal ramp distension from 10 to 60 cmH2O was increased following endotoxin pretreatment compared to controls (p < 0.05). This increase in sensitivity following endotoxin was no longer observed after Doxantrazole or Naproxen administration for pressures from 10 to 30 cmH2O (p < 0.05). Selective COX-2 inhibition by NS398 (10 μM) but not COX-1 inhibition by SC560 (300 μM) reduced increased afferent discharge in endotoxin pretreated animals to 5-HT, BK and mechanical ramp distension from 10 to 40 cmH2O (all p < 0.05). CONCLUSIONS & INFERENCES Systemic endotoxin sensitizes mesenteric afferent nerve fibers to 5-HT, BK and mechanical stimuli. The underlying mechanism responsible for this sensitization seems to involve mast cells and the COX-2 pathway.
Collapse
Affiliation(s)
- B Xue
- Department of Pathophysiology, Medical School, Shandong University, Jinan, China; Department of Surgery, Ludwig-Maximilians University, Munich, Germany
| | | | | | | |
Collapse
|