Content of meiosis activating sterols in equine follicular fluids: correlation to follicular size and dominance.
Abstract: Meiosis activating sterols (MAS) are pre-cholesterol sterols that can be isolated from follicular fluid (FF-MAS) or testes (T-MAS). Meiosis activating sterols trigger the resumption of meiosis in cultured meiotically competent oocytes. In the present work MAS, cholesterol and progesterone were assayed by HPLC in follicular fluids collected from pony mares at fixed days after the last ovulation. Follicles were divided into two groups according to whether they were aspirated before or after Day 17 after the last ovulation. The latter group was further divided according to whether the follicle diameter was 27 mm. Both FF-MAS and T-MAS were detected in almost all samples. Overall, the total amount of MAS in the follicular fluids increased with the size of the follicles but was accompanied by a decrease in the amount of free cholesterol. The amounts of MAS and progesterone in > 27 mm follicles aspirated after Day 17 were significantly higher as compared to the other groups. A transversal cohort analysis showed that the largest follicle at the time of aspiration had the highest level of MAS after day 17 of the cycle, which was not always true for follicle samples aspirated before Day 17 of the cycle. The study demonstrates that the content of MAS in equine follicular fluids increased during follicular maturation concomitant with a decrease in the concentration of free cholesterol. Moreover, MAS concentration is higher in dominant follicles than in subordinate follicles. The MAS may therefore play an as yet unknown physiological role during pre-ovulatory maturation.
Publication Date: 2001-07-27 PubMed ID: 11467509DOI: 10.1016/s0093-691x(01)00549-0Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
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 the concentration of meiosis activating sterols (MAS) in horse follicular fluids. The study found that MAS concentration grows with follicular maturation and is higher in dominant follicles.
Objective of the Research
- This study was undertaken to determine and compare the concentration of meiosis activating sterols (MAS), cholesterol, and progesterone in the follicular fluids of pony mares, with regards to follicular size and dominance.
Approach to the Research
- The researchers conducted their study by using High-Performance Liquid Chromatography (HPLC) to assay MAS, cholesterol, and progesterone in follicular fluids in mares.
- They collected the follicular fluids at set points after the last ovulation and segmented the follicles into groups based on whether they were aspirated before or after Day 17 post ovulation.
- The follicles later were classified according to size: = 22 mm or > 27 mm.
Key Findings
- Overall, the MAS amount in the follicular fluids was found to elevate with the increase in follicle size. This rise was observed alongside a decrease in the amount of free cholesterol.
- The follicles aspirated after Day 17 and of size > 27 mm had significantly higher amounts of MAS and progesterone compared to the other groups.
- The largest follicle at the point of aspiration had the highest amount of MAS after day 17 in the follicular cycle. This, however, was not consistently true for follicle samples aspirated before Day 17.
Conclusion
- The researchers concluded that the MAS content in equine follicular fluids elevates during follicular maturation, and this happens concomitantly with a decrease in the concentration of free cholesterol.
- It was also observed that the MAS concentration was higher in dominant follicles as compared to subordinate follicles, suggesting a possible physiological role of MAS in pre-ovulatory maturation that is not yet fully understood.
Cite This Article
APA
Baltsen M, Bøgh IB, Byskov AG.
(2001).
Content of meiosis activating sterols in equine follicular fluids: correlation to follicular size and dominance.
Theriogenology, 56(1), 133-145.
https://doi.org/10.1016/s0093-691x(01)00549-0 Publication
Researcher Affiliations
- Laboratory of Reproductive Biology, The Rigshospital, Copenhagen, Denmark.
MeSH Terms
- Animals
- Cholestadienols / metabolism
- Cholestenes / analysis
- Cholestenes / metabolism
- Cholesterol / metabolism
- Estrus / metabolism
- Female
- Follicular Fluid / metabolism
- Horses / metabolism
- Horses / physiology
- Lanosterol / metabolism
- Ovarian Follicle / anatomy & histology
- Ovarian Follicle / metabolism
- Progesterone / metabolism
- Statistics, Nonparametric
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
