Systemic and Intrafollicular Androgen Concentrations in Cycling Mares.
Abstract: The evidence that androgens regulate the folliculogenesis supports the hypothesis that intrafollicular testosterone (T), androstenedione (A) and dehydroepiandrosterone (DHEA) could be modified along follicular growth. The objective of this study was to evaluate the changes and related relationships between systemic and intrafollicular T, A and DHEA in post-deviation and impending ovulation follicles. Sixty ovaries were taken after the slaughter of 30 clinically healthy mares. In according to the sizes, the follicles were classified in 3 different categories, as small (20-30 mm), medium (31-40 mm) and large (≥ 41 mm), and the follicular fluid (FF) samplings were extracted from each single follicle. Intrafollicular concentrations of T, A and DHEA were significantly higher than systemic ones. Intrafollicular and systemic T and A concentrations were strongly and positively correlated, and DHEA negatively. A was the predominant androgen in FF. T and A were positively and DHEA negatively correlated with the follicular diameter. T and A significantly increased in large and medium than small follicle sizes. DHEA was significantly higher in small than medium and large follicle size. The increase of intrafollicular androgens suggests the presence of androgenic environment based in the biotransformation of DHEA in A and later in T in the follicles, and the progressive oestradiol-17β (E) production with the advance of follicular growth. The evidence of significant correlations between systemic and intrafollicular androgens considerably helps to understanding more deeply the role of these steroids in the physiology of follicular development in the mare, adding a new segment of scientific literature.
Copyright © 2021. Published by Elsevier Inc.
Publication Date: 2021-09-11 PubMed ID: 34670694DOI: 10.1016/j.jevs.2021.103759Google Scholar: Lookup
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- Journal Article
Summary
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The research study explores the role of certain androgens (male sex hormones) in the development of ovarian follicles in horses. The results reveal significant correlations between systemic and intrafollicular androgen concentrations, enhancing our understanding of their role in follicular development.
Objective and Methodology
- The main objective of this research was to decipher the changes in intrafollicular and systemic concentrations of three androgens – testosterone (T), androstenedione (A), and dehydroepiandrosterone (DHEA) in post-deviation and impending ovulation follicles in mares (female horses).
- To achieve this, sixty ovaries, sourced from thirty healthy mares that had been slaughtered, were examined. Based on their sizes, the follicles were classified into three categories: small (20-30 mm), medium (31-40 mm), and large (≥ 41 mm). Follicular fluid (FF) samples were extracted from each follicle.
Findings
- The concentration levels of T, A, and DHEA were significantly higher in the intrafollicular fluid than in the systemic environment.
- There was a strong positive correlation between intrafollicular and systemic concentrations of T and A. However, a negative correlation was observed for DHEA.
- A was the dominant androgen in the follicular fluid. In comparison, T and A were positively correlated with follicle diameter, whereas DHEA had a negative correlation.
- T and A concentrations were significantly higher in large and medium follicles compared to small ones, while DHEA concentration was highest in the small-sized follicles, indicating a possible role in early follicular development.
Implications and Conclusions
- The high concentration of androgens within follicles suggests an androgenic environment, which implies that the DHEA is transformed into A and subsequently into T within the follicles. This process is accompanied by the production of oestradiol-17β (E), a form of estrogen, as the follicle growth progresses.
- The close correlation between systemic and intrafollicular androgen concentrations can provide valuable insights into the role of these hormones in the physiological process of follicular development in mares. This research contributes a new dimension to existing scientific literature on equine fertility.
Cite This Article
APA
Satué K, Fazio E, Cravana C, Medica P.
(2021).
Systemic and Intrafollicular Androgen Concentrations in Cycling Mares.
J Equine Vet Sci, 106, 103759.
https://doi.org/10.1016/j.jevs.2021.103759 Publication
Researcher Affiliations
- Department of Animal Medicine and Surgery, Faculty of Veterinary, Cardenal Herrera-CEU University, Valencia, Spain. Electronic address: ksatue@uchceu.es.
- Department of Veterinary Sciences, Unit Veterinary Physiology, Polo Universitario Annunziata, Messina University, Italy.
- Department of Veterinary Sciences, Unit Veterinary Physiology, Polo Universitario Annunziata, Messina University, Italy.
- Department of Veterinary Sciences, Unit Veterinary Physiology, Polo Universitario Annunziata, Messina University, Italy.
MeSH Terms
- Androgens
- Androstenedione
- Animals
- Female
- Follicular Fluid
- Horses
- Ovarian Follicle
- Ovulation
Citations
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