Relationship of follicle deviation with intrafollicular and systemic estradiol concentrations in mares

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

doi:10.1016/s0093-691x(99)91859-9

Cited by 24 publications

(49 citation statements)

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“…In the current study, the diameter of the four tracked large follicles on day 1 after ovulation was ≥10 mm and was similar to the diameter of the six large follicles previously reported in pony mares (Ginther et al, 2007). Similarly, one out the four tracked large follicles studied continued growth and became the dominant follicle but another large follicle of nearly the same diameter reduced growth and became subordinate follicles (Gastal et al, 1997(Gastal et al, , 1999bGinther et al, 2004aGinther et al, , 2007Ginther et al, , 2009. Mean diameter of the next dominant follicle at the beginning of deviation observed here was 22.7 ± 0.7 mm and reached 28.7 ± 1.9 mm one day later that is similar to several previously reported diameters of the future dominant follicle at the beginning of deviation (23.7 ± 0.6 mm) in pony mares (Ginther, 1993(Ginther, , 2000Donadeu and Ginther, 2004).…”

Section: Discussionsupporting

confidence: 88%

“…Follicle selection and deviation in mares (Gastal et al, 1997(Gastal et al, , 1999b(Gastal et al, , 2006Donadeu and Ginther, 2004), and cattle (Ginther et al, 1996;Fortune et al, 2001), depended on comparing diameter of recruited follicles but other morphological dimensions of the follicle such as follicle area, volume and follicle antrum growth had not received much interest in such species. Follicular antrum growth was studied in primate (Wulff et al, 2002) and recently several hypotheses were tested for explaining the development of follicular fluid within the antrum (Rodgers and Irving-Rodgers, 2010).…”

Section: Introductionmentioning

confidence: 99%

“…Doppler ultrasound had been used in cattle to study follicular blood flow of the first follicular wave and follicle deviation (Acosta et al, 2005;Pancarc et al, 2011;Miura et al, 2014), and in mare to compare the future dominant and subordinate follicle blood flow (Gastal et al, 1999a;Acosta et al, 2004a, b). In mares, dominant next ovulatory follicle starts deviation from 2.2 cm till reach ≥3.0 cm in diameter but the follicle that reached diameter of 2.2 cm but transiently stopped growth then resumed growth but its diameter is always few mm lower than the dominant one (<3.0 cm) is considered next subordinate (Gastal et al, 1997(Gastal et al, , 1999bGinther et al, 2004aGinther et al, , 2007Ginther et al, , 2009.…”

Section: Introductionmentioning

confidence: 99%

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Follicular blood flow, antrum growth and angiogenic mediators in mares from ovulation to deviation

El‐Maaty¹,

Abdelnaby²

2017

Anim Reprod

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This study assumed that vascular perfusion, antrum growth, leptin, nitric oxide (NO) and insulin like growth factor 1 (IGF-1) play an important role during selection and deviation of mares' next dominant follicle. Five broad mares were subjected to daily rectal Doppler ultrasonographic examination and blood sampling for 2 successive estrous cycles (n = 10). Using electronic calipers, three diameters were taken to estimate area and volume of first (F1O) and second large follicles (F2O) on the ovulated ovary with first (F1C) and second large follicles (F2C) on contralateral ovary. Follicles' area, circumference, antrum area, area of color-and power-Doppler were measured in pixels. Days after ovulation affected significantly (P < 0.0001) follicles blood flow, dimensions and measured hormones. On day 4 after ovulation, the follicle that had a mean diameter of 1.31 ± 0.06 and reached to 1.41 ± 0.06 cm on day 5, the lowest area/cm 2 (1.38 ± 0.18), highest area/pixsel (10229 ± 366), antrum/pixel (7671 ± 357), highest volume (5.54 ± 0.09), lowest power blood flow area (2060.25 ± 8.52) and percent colored pixels of follicle without antrum (80.57 ± 0.72) was selected. Deviation started from day 9 and completed on day 10 where the dominant follicle attained the highest diameter, area, volume, area and antrum area in pixels, color blood flow red area, and percent of colored pixels of follicle without its antrum, leptin, IGF-1 and NO but the lowest power blood flow area and percent of total follicle colored pixels. Our assumption that follicle selection and deviation did not depend only on diameter but also on blood flow, antrum growth, leptin and IGF-1 was proved.

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Section: Discussionsupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Follicular blood flow, antrum growth and angiogenic mediators in mares from ovulation to deviation

El‐Maaty¹,

Abdelnaby²

2017

Anim Reprod

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“…The large amount of E 2 release when the follicle reaches more than 30 mm in diameter is due to the ability of the granulosa cells in synthesizing oestrogen. Gastal et al [10] observed that the differences in E 2 concentrations between larger and smaller follicles increased progressively. Those authors observed that the first significant increase in systemic E 2 occurred the day before or at the beginning of the pre-ovulatory follicle selection.…”

Section: Discussionmentioning

confidence: 97%

Effects of LH and PGF2.ALPHA. in Equine Dominant Follicles Observed by MDS.

Kojima

Kobayashi

Acosta

et al. 2002

The Journal of Veterinary Medical Science

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ABSTRACT. Microdialysis System (MDS) is a novel technique used for investigation of molecule secretion between different cell populations. Local hormonal secretion at follicular wall has been still unclear. This MDS study was used to determine progesterone (P 4 ), androstenedione (A 4 ), estradiol-17β (E 2 ) and Prostaglandin F 2α (PGF 2α ) release in mare pre-ovulatory follicles. Follicles larger than 30 mm were isolated from the ovary and follicular fluid aspirated for hormone assay. Follicular fluid collected from small, middle and large follicles were analyzed by EIA. The concentrations of P 4 and PGF 2α were similar among the different sizes of follicles. The release of A 4 was observed in middle and large follicles. E 2 concentration was observed in middle follicles and was higher in large follicles compared with middle follicles. Follicular wall was cut and incubated for MDS and when LH was infused, there was an increase in P4 and A 4 release. PGF 2α release was considerably high after LH infusion compared to the control group. Infusion of PGF 2α increased P 4 and A 4 release but there was no change in E 2 release. This results suggest that in pre-ovulatory follicles, LH stimulates theca interna cells and also PGF 2α seemed to have a mediator role to induce steroid hormone production and luteinization of follicular cells. The nature of the mechanisms involved in selection of large follicles is still a perplexing research problem in reproduction. KEY WORDS: follicle, mare, MDS, ovulation, steroid-hormone.J. Vet. Med. Sci. 64(2): 119-122, 2002 Mares are seasonal polyestrous animals and the estrous cycle have several unique characteristics, including a long period of estrus, a considerable larger size of preovulatory follicles and the absence of a typical LH surge compared with other species [2,7,9]. However, endocrinological changes that occur in the different follicular compartments (theca, granulosa cells and follicular fluid) during follicular development, maturation, and ovulation still remain unclear.Follicles isolated from mare ovaries maintained the ability to secrete steroid hormones and to respond to hormonal stimulation in vitro [18]. The same study demonstrated a variable effect of LH on progesterone (P 4 ), androstenedione (A 4 ), and estradiol-17β (E 2 ) production depending on the stage of the estrous cycle. A 4 is one of the main secretory products of the theca layer that serve as substrate for the synthesis of estradiol in the granulosa cells [4,19]. These secretory products (steroids and/or prostaglandins) are accumulated in the follicular fluid and may be used as indicators of the follicular development, atretic stage or the proximity of ovulation [21,22]. Moreover, other report suggests that progesterone can modulate ovarian activity by altering FSH and LH receptor in the follicular wall [11]. In addition, prostaglandins have been considered as an essential mediator for the LH action on the ovulatory processes in several species, including the mares [13].Prominent structural and secre...

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“…O desvio folicular se dá a partir do momento em que os dois maiores folículos alteram a taxa de crescimento diário (Gastal et al, 1999b). Nesse estudo, o número médio de folículos em crescimento no momento do desvio folicular foi comparado entre o grupo controle e o grupo tratado com EPE, não apresentando diferença significativa (P>0,05).…”

Section: Arqunclassified

Estudo da vascularização folicular e do corpo lúteo de éguas cíclicas tratadas com extrato de pituitária equina utilizando ultrassom Doppler colorido

Medeiros

Farinasso²,

Nery

et al. 2017

Arq. Bras. Med. Vet. Zootec.

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Relationship of follicle deviation with intrafollicular and systemic estradiol concentrations in mares

Cited by 24 publications

References 0 publications

Follicular blood flow, antrum growth and angiogenic mediators in mares from ovulation to deviation

Follicular blood flow, antrum growth and angiogenic mediators in mares from ovulation to deviation

Effects of LH and PGF2.ALPHA. in Equine Dominant Follicles Observed by MDS.

Estudo da vascularização folicular e do corpo lúteo de éguas cíclicas tratadas com extrato de pituitária equina utilizando ultrassom Doppler colorido

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