Serrated granulosa and other discrete ultrasound indicators of impending ovulation in mares

Gastal, E.L.; Gastal, M.O.; Ginther, O.J.

doi:10.1016/j.jevs.2005.12.005

Cited by 27 publications

(16 citation statements)

References 13 publications

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“…Mares with a growing 28-mm follicle 15 days after ovulation were scanned daily by B-mode ultrasonography until a !32-mm follicle was detected. Estrous cycles were not used if the !32-mm follicle showed ultrasonographic signs of impending ovulation [11], the corpus luteum was large with an echotexture characteristic of a functional structure [20], two dominant follicles (.28 mm) were present, the score for endometrial edema was characteristic of diestrus (score , 3; [21]), or if ovulation occurred before the oocyte-recovery procedure 30 h later. After removal of estrous cycles, 60 cycles in 37 mares remained.…”

Section: Methodsmentioning

confidence: 99%

“…Several discrete structural changes that are detectable by Bmode ultrasonography occur in the follicle as ovulation approaches and are indicators of follicle maturity and the imminence of ovulation [11]. Serration of the granulosa becomes distinct, beginning about 6 h before ovulation [11] in the follicle wall opposite the future site of follicle rupture [12].…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Serration of the granulosa becomes distinct, beginning about 6 h before ovulation [11] in the follicle wall opposite the future site of follicle rupture [12]. Other indicators of impending ovulation include a decrease in follicle turgidity and the development of an apical area and echoic spots that float in the antrum [11]. Blood flow increases in the wall of the preovulatory follicle during the 36 h after hCG treatment, based on an increase in the percentage of the circumference of the follicle wall containing color-Doppler signals for blood flow [13].…”

Section: Introductionmentioning

confidence: 99%

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Relationships of Follicle Versus Oocyte Maturity to Ultrasound Morphology, Blood Flow, and Hormone Concentrations of the Preovulatory Follicle in Mares1

Ginther¹,

Gastal

Gastal³

et al. 2007

Biology of Reproduction

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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.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Relationships of Follicle Versus Oocyte Maturity to Ultrasound Morphology, Blood Flow, and Hormone Concentrations of the Preovulatory Follicle in Mares1

Ginther¹,

Gastal

Gastal³

et al. 2007

Biology of Reproduction

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“…The thickness of the follicle wall (granulosa layer) was determined by averaging measurements made on three different locations (Gastal et al 1998. In addition, the following qualitative B-mode characteristics of the preovulatory follicle were recorded from Hour 0 until ovulation or LUF formation: i) presence of echoic foci floating in the antrum, ii) detection of follicle wall serration (i.e., irregular or notched surfaces of the granulosa layer; Gastal et al 2007), and iii) loss of spherical shape.…”

Section: Ultrasound Evaluationsmentioning

confidence: 99%

The mare as a model for luteinized unruptured follicle syndrome: intrafollicular endocrine milieu

Bashir¹,

Gastal²,

Tazawa³

et al. 2016

Reproduction

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Luteinized unruptured follicle (LUF) syndrome is a recurrent anovulatory dysfunction that affects up to 23% of women with normal menstrual cycles and up to 73% with endometriosis. Mechanisms underlying the development of LUF syndrome in mares were studied to provide a potential model for human anovulation. The effect of extended increase in circulating LH achieved by administration of recombinant equine LH (reLH) or a short surge of LH and decrease in progesterone induced by prostaglandin F 2 a (PGF 2 a) on LUF formation (Experiment 1), identification of an optimal dose of COX-2 inhibitor (flunixin meglumine, FM; to block the effect of prostaglandins) for inducing LUFs (Experiment 2), and evaluation of intrafollicular endocrine milieu in LUFs (Experiment 3) were investigated. In Experiment 1, mares were treated with reLH from Day 7 to Day 15 (Day 0Zovulation), PGF 2 a on Day 7, or in combination. In Experiment 2, FM at doses of 2.0 or 3.0 mg/kg every 12 h and human chorionic gonadotropin (hCG) (1500 IU) were administered after a follicle R32 mm was detected. In Experiment 3, FM at a dose of 2.0 mg/kg every 12 h plus hCG was used to induce LUFs and investigate the intrafollicular endocrine milieu. No LUFs were induced by reLH or PGF 2 a treatment; however, LUFs were induced in 100% of mares using FM. Intrafollicular PGF 2 a metabolite, PGF 2 a, and PGE 2 were lower and the ratio of PGE 2 :PGF 2 a was higher in the induced LUF group. Higher levels of intrafollicular E2 and total primary sex steroids were observed in the induced LUF group along with a tendency for higher levels of GH, cortisol, and T; however, LH, PRL, VEGF-A, and NO did not differ between groups. In conclusion, this study reveals part of the intrafollicular endocrine milieu and the association of prostaglandins in LUF formation, and indicates that the mare might be an appropriate model for studying the poorly understood LUF syndrome.

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Hemodynamic, endocrine, and gene expression mechanisms regulating equine ovarian follicular and cellular development

Wischral

Pastorello

Gastal

et al. 2021

Molecular Reproduction Devel

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Ovulatory follicle development and associated oocyte maturation involve complex coordinated molecular and cellular mechanisms not yet fully understood. This study addresses the relationships among follicle diameter, follicle wall blood flow, follicular‐fluid factors, and gene expression for follicle growth, steroidogenesis, angiogenesis, and apoptosis in granulosa/cumulus cells and oocytes during different stages from the beginning of largest/ovulatory follicle to impending ovulation in mares. The most remarkable findings were (i) a positive association between follicle development, follicle blood flow, intrafollicular follicle‐stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone, and messenger RNA (mRNA) expression for FSHR and LHCGR in granulosa cells of the largest/ovulatory follicle; (ii) a plateau or decrease in follicle diameter and blood flow and granulosa cell mRNA for FSHR, LHCGR, IGF1R, VEGFR2, CYP19A1, and CASP3 at the preovulatory stage; (iii) higher StAR and BCL2 and lower CASP3 mRNA in granulosa cells at the time of impending ovulation; (iv) greater IGF1R mRNA for granulosa cells at the predeviation stage; and (v) lower FSHR, LHCGR, IGF1R, and VEGFR2 mRNA in cumulus cells and greater LHCGR and IGF1R mRNA in oocytes at the ovulatory stage. This study is a critical advance in the understanding of molecular mechanisms of follicle development and oocyte maturation and is expected to be vital for future studies targeting potential markers.

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Serrated granulosa and other discrete ultrasound indicators of impending ovulation in mares

Cited by 27 publications

References 13 publications

Relationships of Follicle Versus Oocyte Maturity to Ultrasound Morphology, Blood Flow, and Hormone Concentrations of the Preovulatory Follicle in Mares1

Relationships of Follicle Versus Oocyte Maturity to Ultrasound Morphology, Blood Flow, and Hormone Concentrations of the Preovulatory Follicle in Mares1

The mare as a model for luteinized unruptured follicle syndrome: intrafollicular endocrine milieu

Hemodynamic, endocrine, and gene expression mechanisms regulating equine ovarian follicular and cellular development

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