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Home / Equine Research Bank / J Equine Sci / Intrafollicular Concentrations of Steroid Hormones and PGF2&...
Journal of equine science2008; 19(2); 31-34; doi: 10.1294/jes.19.31

Intrafollicular Concentrations of Steroid Hormones and PGF2α in Relation to Follicular Development in the Mares during the Breeding Season.

Abstract: The concentrations of androstenedione, estradiol-17β, progesterone and PGF2α contained in the follicular fluid produced by the follicles in collected ovaries of mares that have had estrous phase during the breeding season were measured and analyzed the relation between the growth stage of follicles and the hormone levels in the follicular fluid. An ultrasonographic diagnostic instrument was used to measure the diameter of the follicles in order to categorize the follicles into three groups the following: 8 small follicles (from 1.0 to less than1.5 cm), 8 medium follicles (from 1.5 to less than 3.0 cm), and 8 large follicles (from 3.0 to 5.0 cm), respectively. The analysis of the follicular fluid in ovaries of estrous mares showed that the concentrations of androstenedione were significantly higher in the medium or large follicles than in the small follicles and the concentrations of estradiol-17β were significantly higher in larger follicles than in the small or medium follicles (P<0.05). The concentrations of progesterone and PGF2α, on the other hand, did not significantly vary regardless of follicluar size. In the follicles within the mare ovaries that have had estrous stage, the concentrations of the hormones related the ovulation, namely androstenedione and estradiol-17β, were higher with larger follicles.
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Publication Date: 2008-07-09 PubMed ID: 24833953PubMed Central: PMC4013943DOI: 10.1294/jes.19.31Google Scholar: Lookup
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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.

The study explores how hormone levels in ovarian follicular fluid relate to follicle growth stages in mares during the breeding season, finding that the concentrations of androstenedione and estradiol-17β were higher in larger follicles.

Context and Purpose of The Study

  • This study aims to understand the relationship between the growth stages of ovarian follicles and the concentrations of specific hormones in the follicular fluid of mares during the estrous cycle within the breeding season.
  • Hormones measured in the follicular fluid include androstenedione, estradiol-17β, progesterone and PGF2α, all of which play crucial roles in the ovulation process.
  • The increased understanding of these hormone levels allows for better understanding of the follicle cycle and could potentially aid in fertility treatments or breeding programs.

Methodology

  • The study utilized ultrasound to measure and categorize follicles into three different sizes: small (1.0 to less than 1.5 cm), medium (1.5 to less than 3.0 cm), and large (3.0 to 5.0 cm).
  • The researchers collected ovaries from mares at the estrous phase during the breeding season and then collected and analysed the follicular fluid from these mares for the four mentioned hormones.

Results of The Study

  • It was found that the concentrations of the hormones androstenedione and estradiol-17β were significantly higher in the medium or large follicles than in the small follicles.
  • Moreover, the concentration of estradiol-17β (an estrogen hormone) was significantly higher in larger follicles than in the small or medium follicles, further suggesting a correlation between follicle size and certain hormone concentrations.
  • Conversely, the concentrations of progesterone and PGF2α hormones did not exhibit significant variation in relation to follicle size.

Implications of The Study

  • The significant increase of the hormones androstenedione and estradiol-17β in larger follicles aligns with their roles in stimulating the ovulation process, suggesting that these hormone levels could potentially act as indicators of follicle readiness for ovulation.
  • The findings also suggest potential implications for fertility treatments. Understanding how hormone levels change with follicle growth could help veterinarians or fertility experts manipulate or monitor breeding programs more effectively.

Cite This Article

APA
Tsukada T, Kojima AY, Sato K, Moriyoshi M, Koyago M, Sawamukai Y. (2008). Intrafollicular Concentrations of Steroid Hormones and PGF2α in Relation to Follicular Development in the Mares during the Breeding Season. J Equine Sci, 19(2), 31-34. https://doi.org/10.1294/jes.19.31

Publication

Journal of equine science
ISSN: 1340-3516
NlmUniqueID: 9503751
Country: Japan
Language: English
Volume: 19
Issue: 2
Pages: 31-34

Researcher Affiliations

Tsukada, Tsutomu
  • Tsukada Livestock Clinic, Mitsuishi, Hokkaido 059-3231, Japan.
Kojima, Anna Yumiko
  • Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
Sato, Kunitada
  • Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
Moriyoshi, Masaharu
  • Department of Large Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan.
Koyago, Masanori
  • Department of Large Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan.
Sawamukai, Yutaka
  • Department of Large Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan.

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This article includes 15 references
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Citations

This article has been cited 1 times.
  1. Satué K, Fazio E, Medica P. Can the Presence of Ovarian Corpus Luteum Modify the Hormonal Composition of Follicular Fluid in Mares?. Animals (Basel) 2020 Apr 9;10(4).
    doi: 10.3390/ani10040646pubmed: 32283596google scholar: lookup
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