Relationships of follicle versus oocyte maturity to ultrasound morphology, blood flow, and hormone concentrations of the preovulatory follicle in mares.
Abstract: The effects of ultrasound morphology, vascularity, and follicular-fluid hormones of the preovulatory follicle on oocyte recovery rate and on follicle and oocyte maturity rates were studied for 60 spontaneous and solitary preovulatory follicles in mares. An ovulation-inducing dose of hCG was given when the follicle was >or=32 mm (Hour 0), and a procedure for oocyte recovery was done 30 h later (Hour 30). Between Hours 0 and 30, diameter of the follicle increased less and circulating estradiol (E2) concentrations decreased more in groups with successful versus nonsuccessful oocyte recovery and in groups with mature versus immature recovered oocytes, as indicated by significant interactions of group and hour. Significant differences in blood-flow end points between groups were not detected. At Hour 30, the frequency of granulosa serration, an indicator of impending ovulation, was higher (P < 0.001), and the number and expansion of granulosa cells in the lavaging fluid, indicators of follicle maturity, were greater in the oocyte-recovery group and in the oocyte-mature group. Follicular-fluid concentrations of E2, progesterone, and free insulin-like growth factor (IGF) 1 were not different between the oocyte-recovery and -nonrecovery groups. Concentration of progesterone was significantly greater, and E2 and free IGF1 were less in the oocyte-mature than in the immature groups. Results indicated that the post-hCG oocyte-recovery and oocyte-maturity rates were positively affected by follicle maturity. Greater follicular-fluid progesterone and lower E2 and free IGF concentrations were associated temporally with maturation of the oocyte but not with maturation of the follicle.
Publication Date: 2007-05-02 PubMed ID: 17475927DOI: 10.1095/biolreprod.107.061184Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research investigates the connection between characteristics of preovulatory follicles in mares, such as ultrasound morphology, blood flow, and follicular-fluid hormones, and the rate of oocyte recovery and maturity. The findings point to a positive effect of follicle maturity on both oocyte recovery and maturity rates. The observed hormone variations were linked to the maturation of the oocyte but not the follicle’s maturation.
Objective and Methodology of the Study
- The objective was to understand the impact of ultrasound morphology, vascularity, and follicular-fluid hormones of the preovulatory follicle on the recovery rate and maturity rates of follicles and oocytes.
- This was investigated on 60 mares with spontaneous and solitary preovulatory follicles.
- Each mare was given an ovulation-inducing dose of hCG when their follicle was 32 mm or larger and an oocyte recovery procedure was conducted 30 hours later.
Follicle and Oocyte Changes Over Time
- Between the time of hCG injection and the oocyte recovery procedure, researchers made several observations.
- The follicle’s diameter increased less, and estradiol concentrations decreased more in mares with successful oocyte recovery, and those with mature versus immature oocytes.
- There were no discernible differences in blood-flow end points between mares with successful and unsuccessful oocyte recovery.
Indicators of Ovulation and Follice Maturity
- At the time of oocyte recovery, granulosa serration, an indicator of impending ovulation, was observed more frequently in mares with successful oocyte recovery and those with mature oocytes.
- Follicular-fluid concentrations of estradiol, progesterone, and free insulin-like growth factor (IGF) 1 were not different between mares with successful and unsuccessful oocyte recovery.
- The concentration of progesterone was observed to be higher and estradiol and free IGF1 were measured to be lower in the group with mature oocytes as compared to the group with immature ones.
Conclusions
- The researchers concluded that the maturity of the follicle had a positive effect on both oocyte recovery and maturity rates.
- Further, the maturation of the oocyte but not the follicle was associated with a greater follicular-fluid progesterone and lower estradiol and free IGF concentrations.
Cite This Article
APA
Ginther OJ, Gastal EL, Gastal MO, Siddiqui MA, Beg MA.
(2007).
Relationships of follicle versus oocyte maturity to ultrasound morphology, blood flow, and hormone concentrations of the preovulatory follicle in mares.
Biol Reprod, 77(2), 202-208.
https://doi.org/10.1095/biolreprod.107.061184 Publication
Researcher Affiliations
- Eutheria Foundation, Cross Plains, Wisconsin 53528, USA. ginther@svm.vetmed.wisc.edu
MeSH Terms
- Animals
- Estradiol / analysis
- Female
- Follicular Fluid / chemistry
- Hormones / analysis
- Horses
- Insulin-Like Growth Factor I / analysis
- Oocytes / growth & development
- Ovarian Follicle / blood supply
- Ovarian Follicle / diagnostic imaging
- Ovarian Follicle / growth & development
- Ovulation
- Progesterone / analysis
- Time Factors
- Tissue and Organ Harvesting / veterinary
- Ultrasonography
Citations
This article has been cited 1 times.- Salazar-Ortiz J, Monget P, Guillaume D. The influence of nutrition on the insulin-like growth factor system and the concentrations of growth hormone, glucose, insulin, gonadotropins and progesterone in ovarian follicular fluid and plasma from adult female horses (Equus caballus).. Reprod Biol Endocrinol 2014 Jul 31;12:72.
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