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Home / Equine Research Bank / Animals (Basel) / The Effects of Androstenone on the Plasma Serotonin, β...
Animals : an open access journal from MDPI2021; 11(6); 1694; doi: 10.3390/ani11061694

The Effects of Androstenone on the Plasma Serotonin, β-Endorphin, and Cortisol Concentrations in Thoroughbred Horses.

Abstract: Androstenone influences the changing behaviors of animals. Previous studies discovered that an androstenone receptor was expressed in horses and treatment with androstenone induced horses to be more compliant. As changes in the level of neuroendocrine factors result in animal behavioral changes, the objective of the study was to monitor the changes in the concentrations of 5-HT, β-endorphin, and cortisol in response to androstenone. Eight thoroughbred horses (five mares and three geldings) were treated with androstenone diluted in jojoba oil (10 µg/mL) and only oil for a control cross-overly. A handler applied the treatments to the horses' nostril and rubbed for 5 s. Blood samples were collected before, 15, 30, and 60 min after each treatment. The concentrations of each neurotransmitter were analyzed by enzyme-linked immunosorbent assay. The concentrations of each neurotransmitter after the treatment were compared to its baseline concentration. The concentration of 5-HT of the androstenone-treated horses remained consistent throughout the experiment, while the concentration of the control group significantly decreased over time. The plasma concentration of β-endorphin in the androstenone-treated group also remained constant, whereas the concentration increased in the control group. Cortisol levels did not change in either the treated or untreated groups. An androstenone treatment triggers changes in the secretion of 5-HT and β-endorphin in horses.
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Publication Date: 2021-06-07 PubMed ID: 34200209PubMed Central: PMC8226760DOI: 10.3390/ani11061694Google Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research paper investigates how a chemical called androstenone impacts the behavior of thoroughbred horses by affecting levels of serotonin, β-endorphin, and cortisol in their blood.

Study Overview

  • The researchers were interested to see if androstenone, a molecule known to change animals’ behaviors, could affect the concentrations of certain neurotransmitters in horses. These neurotransmitters – serotonin, β-endorphin, and cortisol – can significantly influence an animal’s behaviour.
  • Before this study, it had been established that horses have receptors for androstenone and that treating horses with this substance made them more compliant. Therefore, the researchers hypothesized that androstenone could be inducing behavioral changes by altering the levels of these neurotransmitters.

    • Methodology

    • They selected eight thoroughbred horses (five mares and three geldings) and treated them with androstenone diluted in jojoba oil. They used jojoba oil without androstenone as a control. This was a crossover study, meaning the same horses were used for both the treated and control groups but at different times.
    • The treatments were applied to the horses’ nostrils and rubbed in for 5 seconds. Blood samples were collected before treatment, and then again 15, 30, and 60 minutes after treatment.
    • The concentrations of each neurotransmitter in the blood samples were analyzed by an enzyme-linked immunosorbent assay. This scientific technique allows scientists to measure the amount of a specific analyte (in this case, the neurotransmitters) in a sample.

    Results and Findings

    • They found that serotonin levels stayed consistent in the horses that were treated with androstenone, but decreased over time in the control group. Similarly, the concentration of β-endorphin remained constant in the androstenone-treated group, while it increased in the control group.
    • No change was observed in cortisol levels in either the treated or control groups.
    • These findings suggest that treatment with androstenone impacts the secretion of serotonin and β-endorphin in horses, and these changes could be influencing horse behaviour.

    Conclusions

    • This study proves that treating horses with androstenone can affect levels of certain chemicals that transmit information within the brain, potentially explaining why this substance makes horses more compliant.
    • However, as this study only included eight horses, more research will be needed to confirm these findings and fully understand the mechanism by which androstenone influences horse behaviour.

Cite This Article

APA
Choi Y, Yoon M. (2021). The Effects of Androstenone on the Plasma Serotonin, β-Endorphin, and Cortisol Concentrations in Thoroughbred Horses. Animals (Basel), 11(6), 1694. https://doi.org/10.3390/ani11061694

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 11
Issue: 6
PII: 1694

Researcher Affiliations

Choi, Yeonju
  • Research Center for Horse Industry, Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Korea.
Yoon, Minjung
  • Research Center for Horse Industry, Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Korea.

Grant Funding

  • 2019-0177 / National Research Foundation of Korea

Conflict of Interest Statement

The authors declare no conflict of interest.

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Citations

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