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A Mechanogenetic Model of Exercise-Induced Pulmonary Haemorrhage in the Thoroughbred Horse. Genes (Basel) 2019; 10:genes10110880. [PMID: 31683933 PMCID: PMC6895809 DOI: 10.3390/genes10110880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/25/2019] [Accepted: 10/30/2019] [Indexed: 12/28/2022] Open
Abstract
Exercise-induced pulmonary haemorrhage (EIPH) occurs in horses performing high-intensity athletic activity. The application of physics principles to derive a ‘physical model’, which is coherent with existing physiology and cell biology data, shows that critical parameters for capillary rupture are cell–cell adhesion and cell stiffness (cytoskeleton organisation). Specifically, length of fracture in the capillary is a ratio between the energy involved in cell–cell adhesion and the stiffness of cells suggesting that if the adhesion diminishes and/or that the stiffness of cells increases EIPH is more likely to occur. To identify genes associated with relevant cellular or physiological phenotypes, the physical model was used in a post-genome-wide association study (GWAS) to define gene sets associated with the model parameters. The primary study was a GWAS of EIPH where the phenotype was based on weekly tracheal wash samples collected over a two-year period from 72 horses in a flat race training yard. The EIPH phenotype was determined from cytological analysis of the tracheal wash samples, by scoring for the presence of red blood cells and haemosiderophages. Genotyping was performed using the Illumina Equine SNP50 BeadChip and analysed using linear regression in PLINK. Genes within significant genome regions were selected for sets based on their GeneOntology biological process, and analysed using fastBAT. The gene set analysis showed that genes associated with cell stiffness (cytoskeleton organisation) and blood flow have the most significant impact on EIPH risk.
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De Mello Costa M, Ronchi F, Yoonsuh J, Ivanow A, Braga J, Ramos M, Casarini D, Slocombe R. ACE activity post-race is influenced by furosemide administration. COMPARATIVE EXERCISE PHYSIOLOGY 2018. [DOI: 10.3920/cep170032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Exercise induced pulmonary haemorrhage (EIPH) affecting racehorses continues to raise questions regarding animal welfare and to-date no effective treatment has been identified. The mode of action of furosemide on EIPH, the only medication for the condition accepted in some racing jurisdictions, has not been completely elucidated. This research investigated the interaction between furosemide on angiotensin converting enzyme (ACE) as a potential pathway for future investigation of EIPH treatment options in a prospective case-control analytical study. ACE is a potent vasoconstrictor and substances reducing its activity could potentially contribute to decreasing blood pressure and EIPH. Horses racing on 8 official race days at Gávea Racetrack, Brazil had respiratory endoscopy data and blood samples collected after the race and were grouped into furosemide medicated and non-furosemide medicated horses. ACE measurement was conducted using fluorescence in a previously validated method. Environmental, race and haematological data were also recorded. A multiple regression model was used to analyse the data collected, with further analysis including Fisher’s exact test and Pearson’s chi-squared test with Yates’ continuity correction; a Welch two sample t-test and a simple linear regression model. 73 horses were included in the study. ACE activity between horses not medicated and medicated with furosemide was significantly different. Pre-race furosemide significantly influenced ACE activity post-race, while distance raced, temperature, humidity, and haematocrit did not. Horses medicated with pre-race furosemide still demonstrated some degree of bleeding after the race and were at higher risk of presenting EIPH than non-medicated horses. Horses medicated with furosemide have lower circulating ACE activity which might indicate a protective effect of furosemide. Furosemide might reduce EIPH severity after a single bout of exercise, but it does not abolish or reduce its occurrence.
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Affiliation(s)
- M.F. De Mello Costa
- Waikato Institute of Technology, Centre for Science and Primary Industries, A Block, Gate 3, Tristram Street, Hamilton, New Zealand
- Universidade Severino Sombra, Veterinary Medicine School, Av. Expedicionário Oswaldo de Almeida Ramos 280 Centro, Vassouras, RJ 27700-000, Brazil
| | - F.A. Ronchi
- Escola Paulista de Medicina, Departamento de Medicina, Disciplina de Nefrologia, UNIFESP, Rua Botucatu, 591, Vila Clementino, SP, Brazil
| | - J. Yoonsuh
- University of Waikato, Hillcrest, Hamilton 3216, New Zealand
- Department of Statistics, Korea University, 145 Anam-ro, Anam-dong, Seongbuk-gu, Seoul, South Korea
| | - A. Ivanow
- Centaur Equine Research Consortium, Auckland, New Zealand
| | - J.V. Braga
- Jockey Club Brasileiro, F e G, Rua Djalma Ulrich 110, Copacabana, Rio de Janeiro 22071-020, Brazil
| | - M.T. Ramos
- Universidade Severino Sombra, Veterinary Medicine School, Av. Expedicionário Oswaldo de Almeida Ramos 280 Centro, Vassouras, RJ 27700-000, Brazil
- Universidade Federal Rural do Rio de Janeiro, BR 465, Km 07. Seropédica, RJ 23897-97, Brazil
| | - D.E. Casarini
- Escola Paulista de Medicina, Departamento de Medicina, Disciplina de Nefrologia, UNIFESP, Rua Pedro de Toledo 669, Sao Paulo, Brazil
| | - R.F. Slocombe
- Veterinary Science, University of Melbourne, 250 Princes Hwy, Werribee, Victoria 3030, Australia
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Poole DC, Erickson HH. Exercise-induced pulmonary hemorrhage: where are we now? VETERINARY MEDICINE (AUCKLAND, N.Z.) 2016; 7:133-148. [PMID: 30050846 PMCID: PMC6044800 DOI: 10.2147/vmrr.s120421] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
As the Thoroughbreds race for the final stretch, 44 hooves flash and thunder creating a cacophony of tortured air and turf. Orchestrated by selective breeding for physiology and biomechanics, expressed as speed, the millennia-old symphony of man and beast reaches its climax. At nearly 73 kilometers per hour (45 mph) over half a ton of flesh and bone dwarfs its limpet-like jockey as, eyes wild and nostrils flaring, their necks stretch for glory. Beneath each resplendent livery-adorned, latherin-splattered coat hides a monstrous heart trilling at 4 beats per second, and each minute, driving over 400 L (105 gallons) of oxygen-rich blood from lungs to muscles. Matching breath to stride frequency, those lungs will inhale 16 L (4 gallons) of air each stride moving >1,000 L/min in and out of each nostril - and yet failing. Engorged with blood and stretched to breaking point, those lungs can no longer redden the arterial blood but leave it dusky and cyanotic. Their exquisitely thin blood-gas barrier, a mere 10.5 μm thick (1/50,000 of an inch), ruptures, and red cells invade the lungs. After the race is won and lost, long after the frenetic crowd has quieted and gone, that blood will clog and inflame the airways. For a few horses, those who bleed extensively, it will overflow their lungs and spray from their nostrils incarnadining the walls of their stall: a horrifically poignant canvas that strikes at horse racing's very core. That exercise-induced pulmonary hemorrhage (EIPH) occurs is a medical and physiological reality. That every reasonable exigency is not taken to reduce/prevent it would be a travesty. This review is not intended to provide an exhaustive coverage of EIPH for which the reader is referred to recent reviews, rather, after a brief reminder of its physiologic and pathologic bases, focus is brought on the latest developments in EIPH discovery as this informs state-of-the-art knowledge, the implementation of that knowledge and recommendations for future research and treatment.
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Affiliation(s)
- David C Poole
- Department of Anatomy and Physiology,
- Department of Kinesiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA,
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