Influence of exercise and emotional stresses on secretion of prolactin and growth hormone in Thoroughbred horses.
Abstract: The secretion of prolactin and growth hormone in response to exercise and emotional stresses was investigated in Thoroughbreds. Two experiments were performed: one with loading of only exercise stress and one with simultaneous loading of exercise and emotional stresses. Exercise stress was loaded in 4 steps using a treadmill for horses: pre-exercise period (5 min), walking period (6.5 min), galloping period (3 min), and cooling down period (10 min). Emotional stress was loaded by showing a loud video of an audience at a racetrack during the walking period. The results clearly demonstrated that exercise stress rapidly increased the secretion of prolactin and growth hormone and that secretion of them persisted for a specific period after the exercise. In addition, emotional stress promoted prolactin secretion.
©2021 The Japanese Society of Equine Science.
Publication Date: 2021-06-18 PubMed ID: 34220271PubMed Central: PMC8240521DOI: 10.1294/jes.32.49Google Scholar: Lookup
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Summary
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This research investigates how exercise and emotional stress impact the secretion of hormones, specifically prolactin and growth hormone, in Thoroughbred horses. It discovered that both exercise and emotional stress amplify the release of these hormones, with the effects lasting for a particular duration post-exercise.
Hormonal Response to Exercise and Emotional Stress
- The main objective of this study was to understand the impact of exercise and emotional stress on the secretion levels of two crucial hormones in Thoroughbreds – prolactin and growth hormone.
- The researchers conducted two experiments, one involving the introduction of only exercise stress, and the second consisting of both exercise and emotional stresses.
Methodologies Utilised
- In the experiments, physical stress was introduced incrementally through a four-step workout on a horse treadmill. This included a pre-exercise stage, a walking period, a galloping phase, and a cooling down phase.
- Emotional stress was instigated by playing a loud video of a racetrack audience during the walking period. The goal was to mimic the stressful conditions that a racehorse might undergo during a competitive event.
Findings of the Study
- The Results of the research showed a surge in prolactin and growth hormone secretion in reaction to the physical exertion, maintaining elevated levels even after the workout session.
- Furthermore, it was found that emotional stress encourages the secretion of prolactin, affirming the significant influence of various forms of stress on hormonal balance in these racehorses.
Implications
- The findings of this study could have significant implications for the training and management of sport horses, as awareness of how stressors impact hormone levels can inform more effective and humane training methods.
- Understanding the prolonged effects of physical stress on hormone secretion in racehorses might help in assessing recovery rates post-training or racing.
- Further research is required to deeply elaborate on the specific relationship between emotional stress and hormonal secretion and how it impacts the health and performance of Thoroughbreds.
Cite This Article
APA
Kitaura T, Sato F, Hada T, Ishimaru M, Kodama R, Nambo Y, Watanabe G, Taya K.
(2021).
Influence of exercise and emotional stresses on secretion of prolactin and growth hormone in Thoroughbred horses.
J Equine Sci, 32(2), 49-53.
https://doi.org/10.1294/jes.32.49 Publication
Researcher Affiliations
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
- United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan.
- Equine Research Institute, Japan Racing Association, Tochigi 329-0412, Japan.
- Ritto Training Center, Japan Racing Association, Shiga 520-3085, Japan.
- Hidaka Training and Research Center, Japan Racing Association, Hokkaido 057-0171, Japan.
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
- United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan.
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan.
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
- United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan.
- Cooperative Division of Veterinary Sciences (Doctoral Program), Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
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