1
|
Hu D, Chao Y, Zhang B, Wang C, Qi Y, Ente M, Zhang D, Li K, Mok KM. Effects of Gasterophilus pecorum infestation on the intestinal microbiota of the rewilded Przewalski's horses in China. PLoS One 2021; 16:e0251512. [PMID: 33974667 PMCID: PMC8112688 DOI: 10.1371/journal.pone.0251512] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/27/2021] [Indexed: 12/11/2022] Open
Abstract
Horse botflies have been a threat to the Przewalski’s horses in the Kalamaili Nature Reserve in Xinjiang of China since their reintroduction to the original range. As larvae of these parasites could infest the intestine of a horse for months, they could interact with and alter the structure and composition of its intestinal microbiota, affecting adversely its health. Nonetheless, there are no such studies on the rewilded Przewalski’s horses yet. For the first time, this study characterizes the composition of the intestinal microbiota of 7 rewilded Przewalski’s horses infected severely by Gasterophilus pecorum following and prior to their anthelmintic treatment. Bioinformatics analyses of the sequence data obtained by amplicon high throughput sequencing of bacterial 16S rRNA genes showed that G. pecorum infestation significantly increased the richness of the intestinal microbial community but not its diversity. Firmicutes and Bacteroidetes were found the dominant phyla as in other animals, and the parasitic infestation decreased the F/B ratio largely by over 50%. Large reduction in relative abundances of the two genera Streptococcus and Lactobacillus observed with G. pecorum infestation suggested possible changes in colic and digestion related conditions of the infected horses. Variations on the relative abundance of the genus groups known to be pathogenic or symbiotic showed that adverse impact of the G. pecorum infestation could be associated with reduction of the symbiotic genera Lactobacillus and Bifidobacterium that are probiotics and able to promote immunity against parasitic infection.
Collapse
Affiliation(s)
- Dini Hu
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Yuzhu Chao
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Boru Zhang
- Qinhuangdao Forestry Bureau, Qinhuangdao, China
| | - Chen Wang
- Altay Management Station of Mt. Kalamaili Ungulate Nature Reserve, Altay, China
| | - Yingjie Qi
- Altay Management Station of Mt. Kalamaili Ungulate Nature Reserve, Altay, China
| | - Make Ente
- Xinjiang Research Centre for Breeding Przewalski’s Horse, Urumqi, China
| | - Dong Zhang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Kai Li
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
- * E-mail: (KL); (KMM)
| | - Kai Meng Mok
- Department of Civil and Environmental Engineering, University of Macau, Macao, China
- * E-mail: (KL); (KMM)
| |
Collapse
|
2
|
Connell D, Shah A. The contribution of Aspergillus fumigatus to COPD exacerbations: a "sensitive" topic. Eur Respir J 2020; 56:56/2/2002223. [PMID: 32855304 DOI: 10.1183/13993003.02223-2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 06/11/2020] [Indexed: 11/05/2022]
Affiliation(s)
- David Connell
- Dept of Respiratory Medicine, NHS Tayside, Dundee, UK.,Division of Molecular and Clinical Medicine, University of Dundee, Dundee, UK
| | - Anand Shah
- Dept of Respiratory Medicine, Royal Brompton and Harefield NHS Foundation Trust, London, UK .,Dept of Infectious Diseases Epidemiology, School of Public Health, Imperial College London, London, UK
| |
Collapse
|
3
|
Schellenberg LM, Bonicelli J, Hochheim I, Regenthal R, Abraham G. Presence and function of β-adrenergic receptors in primary equine bronchial epithelia cells. Pulm Pharmacol Ther 2020; 61:101897. [PMID: 31962137 DOI: 10.1016/j.pupt.2020.101897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 09/23/2019] [Accepted: 01/16/2020] [Indexed: 11/16/2022]
Abstract
The β-adrenergic receptor (β-AR) plays an important role in regulating a variety of cell and organ functions in different animal species and is an important target in asthma pathogenesis and therapy. The β-AR expression and function in equine bronchial epithelial cells (EBEC) were not known but innervation and significant decrease in receptor level were reported in the equine bronchial tissues from asthmatic horses. 125I-iodocyanopindolol (ICYP) binding studies were undertaken in primary freshly isolated and cultured EBEC to identify the presence of the β-ARs. The receptor distribution was assessed using subtype-selective β-AR antagonists (ICI 118 551 (β2) and CGP 20712A (β1). The β-AR function was confirmed by measuring the agonist-induced intracellular cAMP accumulation in freshly isolated and cultured EBEC. In both freshly isolated and cultured EBEC, the specific ICYP binding was saturable and of high affinity. The maximal receptor density (Bmax) was 9763 ± 140 binding sites/cell (mean ± SEM, n = 7) and 10575 ± 194 binding sites/cell (mean ± SEM, n = 5) in freshly isolated and cultured EBEC, respectively. The receptor affinity to the ligand (KD) was also not different between the two cell conditions. ICI 118.551 displaced ICYP with 25 000-fold higher affinity than CGP 20712A. Moreover, in both fresh isolated and cultured EBEC, cAMP-accumulation was stimulated with a rank-order of potency of isoproterenol > adrenaline > noradrenaline. These results highlight the β2-AR to be a key subtype in both freshly isolated and cultured primary EBEC.
Collapse
Affiliation(s)
- Linda Marie Schellenberg
- University of Leipzig, Faculty of Veterinary Medicine, Institute of Pharmacology, Pharmacy and Toxicology, An den Tierkliniken 15, 04103, Leipzig, Germany
| | - Jana Bonicelli
- University of Leipzig, Faculty of Veterinary Medicine, Institute of Pharmacology, Pharmacy and Toxicology, An den Tierkliniken 15, 04103, Leipzig, Germany
| | - Ina Hochheim
- University of Leipzig, Faculty of Veterinary Medicine, Institute of Pharmacology, Pharmacy and Toxicology, An den Tierkliniken 15, 04103, Leipzig, Germany
| | - Ralf Regenthal
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, Clinical Pharmacology, Faculty of Medicine, Leipzig University, Leipzig, Germany.
| | - Getu Abraham
- University of Leipzig, Faculty of Veterinary Medicine, Institute of Pharmacology, Pharmacy and Toxicology, An den Tierkliniken 15, 04103, Leipzig, Germany.
| |
Collapse
|
4
|
Pozzoli C, Bertini S, Poli E, Placenza G, Menozzi A. Relaxing effects of clenbuterol, ritodrine, salbutamol and fenoterol on the contractions of horse isolated bronchi induced by different stimuli. Res Vet Sci 2019; 128:43-48. [PMID: 31710963 DOI: 10.1016/j.rvsc.2019.10.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 09/10/2019] [Accepted: 10/23/2019] [Indexed: 12/12/2022]
Abstract
β2-adrenoceptor agonists are considered the most effective drugs to counteract bronchoconstriction in horses with asthma, but only clenbuterol is commonly employed in clinical practice. We evaluated the effects of different selective β2 agonists: clenbuterol, ritodrine, salbutamol, and fenoterol on the contractions of isolated bronchial muscle of horses induced by electrical field stimulation (EFS), carbachol, histamine, and KCl. All β2 agonists reduced the amplitude of contraction induced by the different stimuli but with variable efficacy and potency. Fenoterol and salbutamol were more effective than clenbuterol in relaxing the bronchial contractions induced by EFS and histamine, and were able to completely abolish carbachol-induced contractions, unlike clenbuterol and ritodrine. The respective potency values (pEC50) of clenbuterol, ritodrine, salbutamol, and fenoterol were 7.74 ± 0.20, 7.77 ± 0.17, 7.30 ± 0.23, 8.01 ± 0.13, for EFS-induced contractions; 8.39 ± 0.26, 5.49 ± 0.28, 6.63 ± 0.14, 7.68 ± 0.11, for carbachol-induced contraction; 7.39 ± 0.27, 7.04 ± 0.28, 6.45 ± 0.34, 7.34 ± 0.22, for histamine-induced contraction; 7.15 ± 0.06, 6.07 ± 0.20, 6.48 ± 0.14, 6.70 ± 0.18, for KCl-induced contraction. Salbutamol and fenoterol showed a higher efficacy than clenbuterol in relaxing horse bronchial muscle pre-contracted by most stimuli. Clenbuterol displayed a good potency but a rather low efficacy, and this may be due to its partial agonist nature; ritodrine showed lower or not significantly different efficacy and potency compared to the other agonists. An evaluation of the clinical efficacy by fenoterol and salbutamol in horses with asthma could be of great interest to assess if they could represent more effective bronchodilators compared to clenbuterol.
Collapse
Affiliation(s)
- Cristina Pozzoli
- Department of Medicine and Surgery, University of Parma, Via Volturno 39, 43125 Parma, Italy
| | - Simone Bertini
- Department of Veterinary Science, University of Parma, Strada del Taglio 10, 43126 Parma, Italy
| | - Enzo Poli
- Department of Medicine and Surgery, University of Parma, Via Volturno 39, 43125 Parma, Italy
| | - Giuseppe Placenza
- Department of Veterinary Science, University of Parma, Strada del Taglio 10, 43126 Parma, Italy
| | - Alessandro Menozzi
- Department of Veterinary Science, University of Parma, Strada del Taglio 10, 43126 Parma, Italy.
| |
Collapse
|
5
|
Abstract
PURPOSE OF REVIEW Farmers are routinely exposed to organic dusts and aeroallergens that can have adverse respiratory health effects including asthma. Horses are farm-reared large animals with similar exposures and can develop equine asthma syndrome (EAS). This review aims to compare the etiology, pathophysiology, and immunology of asthma in horses compared to farmers and highlights the horse as a potential translational animal model for organic dust-induced asthma in humans. RECENT FINDINGS Severe EAS shares many clinical and pathological features with various phenotypes of human asthma including allergic, non-allergic, late onset, and severe asthma. EAS disease features include variable airflow obstruction, cough, airway hyperresponsiveness, airway inflammation/remodeling, neutrophilic infiltrates, excess mucus production, and chronic innate immune activation. Severe EAS is a naturally occurring and biologically relevant, translational animal disease model that could contribute to a more thorough understanding of the environmental and immunologic factors contributing to organic dust-induced asthma in humans.
Collapse
Affiliation(s)
- M. Katie Sheats
- Comparative Medicine Institute, Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607, USA
| | - Kaori U. Davis
- Comparative Medicine Institute, Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607, USA
| | - Jill A. Poole
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Nebraska Medical Center, 985990 Nebraska Medical Center, Omaha, NE 68198-5990, USA
| |
Collapse
|
6
|
Sheats MK, Pescosolido KC, Hefner EM, Sung EJ, Adler KB, Jones SL. Myristoylated Alanine Rich C Kinase Substrate (MARCKS) is essential to β2-integrin dependent responses of equine neutrophils. Vet Immunol Immunopathol 2014; 160:167-76. [PMID: 24857637 DOI: 10.1016/j.vetimm.2014.04.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/24/2014] [Accepted: 04/25/2014] [Indexed: 01/13/2023]
Abstract
Neutrophil infiltration is a prominent feature in a number of pathologic conditions affecting horses including recurrent airway obstruction, ischemia-reperfusion injury, and laminitis. Cell signaling components involved in neutrophil migration represent targets for novel anti-inflammatory therapies. In order to migrate into tissue, neutrophils must respond to chemoattractant signals in their external environment through activation of adhesion receptors (i.e. integrins) and reorganization of the actin cytoskeleton. Myristoylated Alanine-Rich C-Kinase Substrate (MARCKS), a highly conserved actin-binding protein, has a well demonstrated role in cytoskeletal dependent cellular functions (i.e. adhesion, spreading, and migration), but the details of MARCKS involvement in these processes remain vague. We hypothesized that MARCKS serves as a link between the actin cytoskeleton and integrin function in neutrophils. Using a MARCKS-specific inhibitor peptide known as MANS on equine neutrophils in vitro, we demonstrate that inhibition of MARCKS function significantly attenuates β2-integrin-dependent neutrophil functions including migration, adhesion, and immune complex-mediated respiratory burst. The MANS peptide did not, however, inhibit the β2-integrin-independent PMA mediated respiratory burst. These results attest to the essential role of MARCKS function in regulating neutrophil responses, and strongly implicate MARCKS as a potential regulator of β2-integrins in neutrophils.
Collapse
Affiliation(s)
- Mary K Sheats
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC 27607, United States; Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC 27607, United States.
| | - Kimberly C Pescosolido
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC 27607, United States
| | - Ethan M Hefner
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC 27607, United States
| | - Eui Jae Sung
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC 27607, United States
| | - Kenneth B Adler
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC 27607, United States
| | - Samuel L Jones
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC 27607, United States; Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC 27607, United States
| |
Collapse
|
7
|
Sohal SS, Ward C, Danial W, Wood-Baker R, Walters EH. Recent advances in understanding inflammation and remodeling in the airways in chronic obstructive pulmonary disease. Expert Rev Respir Med 2014; 7:275-88. [PMID: 23734649 DOI: 10.1586/ers.13.26] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The authors have reviewed the current literature on airway inflammation and remodeling in smoking-related chronic obstructive pulmonary disease (COPD). Detailed data on airway remodeling in COPD are especially sparse and how these changes lead to decline in lung function is not well understood. Small airway fibrosis and obliteration are likely to be the main contributors to physiological airway dysfunction and occur earlier than any subsequent development of emphysema. One potential mechanism contributing to small airway fibrosis/obliteration and change in extracellular matrix is epithelial-mesenchymal transition. When associated with angiogenesis (so-called epithelial-mesenchymal transition type 3) it may well also be the link with the development of cancer, which is closely associated with COPD, predominantly in large airways. The authors have focused on our recent publications in these areas. Further investigations teasing out these mechanisms will help improve our understanding of key airway disease processes in COPD, which may have major therapeutic implications.
Collapse
Affiliation(s)
- Sukhwinder Singh Sohal
- National Health and Medical Research Council Centre of Research Excellence for Chronic Respiratory Disease, School of Medicine, University of Tasmania, 17 Liverpool Street, Private Bag 23, Hobart, Tasmania 7000, Australia
| | | | | | | | | |
Collapse
|
8
|
Pirie RS. Recurrent airway obstruction: a review. Equine Vet J 2014; 46:276-88. [PMID: 24164473 DOI: 10.1111/evj.12204] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 10/05/2013] [Indexed: 12/01/2022]
Abstract
Recurrent airway obstruction is a widely recognised airway disorder, characterised by hypersensitivity-mediated neutrophilic airway inflammation and lower airway obstruction in a subpopulation of horses when exposed to suboptimal environments high in airborne organic dust. Over the past decade, numerous studies have further advanced our understanding of different aspects of the disease. These include clarification of the important inhaled airborne agents responsible for disease induction, improving our understanding of the underlying genetic basis of disease susceptibility and unveiling the fundamental immunological mechanisms leading to establishment of the classic disease phenotype. This review, as well as giving a clinical overview of recurrent airway obstruction, summarises much of the work in these areas that have culminated in a more thorough understanding of this debilitating disease.
Collapse
Affiliation(s)
- R S Pirie
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Roslin, Midlothian, UK
| |
Collapse
|
9
|
Aharonson-Raz K, Lohmann KL, Townsend HG, Marques F, Singh B. Pulmonary intravascular macrophages as proinflammatory cells in heaves, an asthma-like equine disease. Am J Physiol Lung Cell Mol Physiol 2012; 303:L189-98. [PMID: 22659880 DOI: 10.1152/ajplung.00271.2011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Heaves, an obstructive neutrophilic airway inflammation of horses, is triggered by dust components such as endotoxin and has similarities to human asthma. Pulmonary intravascular macrophages (PIMs) increase horses' sensitivity to endotoxin-induced lung inflammation; however, their role in an airborne pathology remains unknown. Therefore, we investigated the role of PIMs in the development of heaves in horses. Clinical and inflammatory responses were evaluated following induction of heaves by moldy hay exposure and PIM depletion with gadolinium chloride (GC). Mares (N = 9) were exposed to four treatments: alfalfa cubes (Cb), alfalfa cubes + GC (Cb-GC), moldy hay (MH), and moldy hay + GC (MH-GC). Clinical scores and neutrophil concentrations in bronchoalveolar lavage (BAL) fluid were higher when mares received MH compared with MH-GC. BAL cells from MH-GC-treated mares had significantly lower IL-8 and TLR4 mRNA expression compared with MH-treated mares. In vitro LPS challenge significantly increased IL-8 but not TLR4 mRNA expression in BAL cells recovered from horses fed with MH, but not from the MH-GC treatment. In summary, PIM depletion attenuated clinical scores, reduced the alveolar migration of neutrophils, and decreased the expression of proinflammatory molecules in BAL cells of heaves horses, suggesting a proinflammatory role of PIMs in the development of airborne pathology.
Collapse
Affiliation(s)
- Karin Aharonson-Raz
- Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Canada
| | | | | | | | | |
Collapse
|
10
|
Aitken MR, Parente EJ. Epiglottic abnormalities in mature nonracehorses: 23 cases (1990–2009). J Am Vet Med Assoc 2011; 238:1634-8. [DOI: 10.2460/javma.238.12.1634] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
11
|
Oslund KL, Adamson G, Wu R. Evaluation of MUC5AC expression and upregulation in airway epithelial cells of horses. Am J Vet Res 2010; 71:690-6. [PMID: 20513186 DOI: 10.2460/ajvr.71.6.690] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To isolate and culture primary equine airway epithelial cells in vitro and elucidate the major cytokines involved in expression of the gel-forming mucin gene MUC5AC in horses. SAMPLE POPULATION 12 tracheas obtained within 5 hours after euthanasia from horses free from respiratory tract disease. PROCEDURES Tracheal rings were digested overnight in 0.2% protease, and dissociated airway epithelial cells were grown in a serum-free defined medium at an air-liquid interface until confluence was achieved. Differentiated airway epithelial cells were treated with a panel of recombinant equine cytokines followed by quantitative reverse transcriptase PCR assay for mRNA of equine MUC5AC and the control gene glyceraldehyde 3-phosphate dehydrogenase. Cultures were incubated in the presence of isohelenin, a nuclear factor kappaB-DNA-binding inhibitor, to investigate transcriptional regulation of MUC5AC. RESULTS Light and electron microscopy revealed a differentiated epithelium with ciliated cells, nonciliated mucous cells, and basal-like cells. Recombinant equine tumor necrosis factor-alpha was the major mediator in the cytokine panel that significantly increased MUC5AC mRNA by a factor of 5 in a dose- and time-dependent manner. This enhancement was attenuated by isohelenin. CONCLUSIONS AND CLINICAL RELEVANCE Data suggested that a nuclear factor KB-based transcriptional mechanism is involved in induction of MUC5AC expression by tumor necrosis factor-A. Understanding the molecular mechanism of cytokine-enhanced MUC5AC expression in horses may lead to better treatment options and understanding of the pathogenesis of equine pulmonary diseases.
Collapse
Affiliation(s)
- Karen L Oslund
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine and Center for Comparative Respiratory Biology and Medicine, School of Medicine, University of California-Davis, Davis, CA 95616, USA.
| | | | | |
Collapse
|
12
|
Identification and characterization of β-adrenergic receptors in isolated primary equine tracheal epithelial cells. Pulm Pharmacol Ther 2010; 24:174-81. [PMID: 20601048 DOI: 10.1016/j.pupt.2010.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 06/04/2010] [Accepted: 06/18/2010] [Indexed: 11/23/2022]
Abstract
Responses and functions of airway epithelial cells are stimulated by β₂-agonists via the β₂-adrenergic receptors (β₂-ARs)-G(s)-protein-cAMP-system, thus, affecting airway inflammation such as in asthma and equine recurrent airway obstruction (RAO). Though horses can be used as large animal model for human asthma, evaluation of the expression and functions of the β-AR system in primary equine airway epithelial cells has not been yet carried out. Thus, for the first time, we determined the β-AR density and subtype distribution by [¹²⁵I]-iodocyanopindolol (ICYP) binding, examined β-AR function by cAMP assay as well as their expression by western blot analysis and immunocytochemical staining in primary equine tracheal epithelial cells (ETEC). Cells were collected from 19 horses and cultured subsequently. The specific ICYP binding was saturable and of high affinity: in freshly isolated cells the receptor density (B(max)) and ICYP affinity (K(D)) for β-ARs were 12727 ± 883 binding sites/cell and 31.78 ± 6.57 pM, respectively, and in cultured ETEC 3730 ± 212 binding sites/cell and 15.26 ± 3.37 pM, respectively. The β-AR subtype assessed by β₁-selective (CGP 20712A) and β₂-selective (ICI 118.551) adrenergic receptor antagonists demonstrated that the β₂-AR subtype predominated (>95%) in both cell populations (p < 0.001). The β-AR agonists increased cAMP formation with a rank order of potency: isoproterenol > epinephrine > norepinephrine. ICI 118.551 (100 nM) significantly blocked (p < 0.05) isoproterenol-induced cAMP accumulation but not CGP 20712A (300 nM). Western blot analyses and immunocytochemical staining further indicated the expression of the β(2)-AR subtype in both cell preparations. Our data indicate that in acutely dissociated and primary cultured ETEC the β(2)-AR-AC system is expressed, but varies considerably between the two preparations.
Collapse
|
13
|
Cunningham FM, Dunkel B. Equine recurrent airway obstruction and insect bite hypersensitivity: understanding the diseases and uncovering possible new therapeutic approaches. Vet J 2007; 177:334-44. [PMID: 18023376 DOI: 10.1016/j.tvjl.2007.10.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 10/02/2007] [Accepted: 10/03/2007] [Indexed: 01/26/2023]
Abstract
Recurrent airway obstruction (RAO) and insect bite hypersensitivity (IBH) are allergic conditions that are commonly encountered in the horse. Whilst complete allergen avoidance is an effective management strategy for both diseases, this may not be achievable in all cases and treatment options are therefore required. The inflammatory response is the main therapeutic target for glucocorticoids given to horses with RAO and severe cases of IBH, whilst the bronchodilators used in RAO primarily target airway smooth muscle. Such drugs are effective in most but not all individuals and there may be unwanted adverse effects. This article will review how knowledge of drug action and the pathogenesis of RAO and IBH can be utilised to identify potential targets for novel therapeutic agents that, in the longer term, may be safer and/or more effective in managing the allergic horse.
Collapse
Affiliation(s)
- Fiona M Cunningham
- Department of Veterinary Basic Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, UK.
| | | |
Collapse
|