Effects of brief postponement of the preovulatory LH surge on ovulation rates and embryo formation in eCG/prostaglandin-treated heifers

Leemput, E.E. van de; Vos, P.L.A.M.; Hyttel, Poul; Hurk, R. van den; Bevers, M.M.; Weijden, G.C. van der; Dieleman, S.J.

doi:10.1016/s0093-691x(01)00427-7

Cited by 28 publications

(13 citation statements)

References 36 publications

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“…A second study used gonadotropinreleasing hormone inhibition to obtain similar results. Increased atresia rate associated with decreased blastocyst rate was noted (Oussaid et al 2000, van de Leemput et al 2001. Although previous studies are consistent with our data supporting a link between largest follicles and a reduced blastocyst rate, it is not possible to rule out that decreased competence may be caused by smaller follicles as the oocytes were not evaluated according to follicular dimension (7-10 mm).…”

Section: Discussionsupporting

confidence: 86%

FSH withdrawal improves developmental competence of oocytes in the bovine model

Nivet¹,

Bunel²,

Labrecque³

et al. 2012

Reproduction

121

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Combinations of genetic, environmental, and management factors are suspected to explain the loss in fertility observed for over 20 years in dairy cows. In some cases, IVF is used. When compared with in vivo embryo production, IVF resulted in low success rates until the FSH coasting process (FSH starvation after superstimulation) was introduced in 2002. Increased competence associated with FSH withdrawal of aspirated oocyte for in vitro maturation and IVF has not been optimized nor explained yet. The goal here was to determine and characterize the optimal oocyte competence acquisition window during the coasting period by determining blastocyst rates and follicular cohort development. Commercial milking cycling cows (nZ6) were stimulated with 3 days of FSH (6!40 mg NIH Folltropin-V given at 12 h intervals) followed by a coasting period of 20, 44, 68, or 92 h. Each animal was exposed to the four conditions and served as its own control. At the scheduled time, transvaginal aspirations of immature oocytes were performed followed by IVF of half the oocytes. The outcomes were as follows: i) FSH coasting was optimal at a defined period: between 44 and 68 h of coasting; ii) The best estimated coasting duration was w54G7 h; iii) Under these conditions, the best statistical blastocyst rate estimation was w70%; iv) Between 44 and 68 h of coasting, follicle size group proportions were similar; v) Follicle diameter was not linearly associated with competence. In conclusion, coasting duration is critical to harvest the oocytes at the right moment of follicular differentiation.

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Section: Discussionsupporting

confidence: 86%

FSH withdrawal improves developmental competence of oocytes in the bovine model

Nivet¹,

Bunel²,

Labrecque³

et al. 2012

Reproduction

121

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“…Reports from Stanchev et al (1985) on the porcine oviduct indicated that high levels of plasma estradiol cause an increase of ER, which is first seen in the cytoplasm and later in the nuclei. Also, in primates (Amso et al 1994;Brenner and Slayden 1994) and in the bovine (van de Leemput et al 2001), an enhanced nuclear ERα expression has been observed in the oviductal epithelium during estrus. Rodríguez-Piñón et al (2005) recently demonstrated that E2 treatment of prepubertal ewes affects ERα and PR transcription in the oviduct and cervix.…”

Section: Discussionmentioning

confidence: 97%

Cellular Expression and Localization of Estrogen Receptor α and Progesterone Receptor mRNA in the Bovine Oviduct Combining Laser-Assisted Microdissection, Quantitative PCR, and In Situ Hybridization

Kenngott

Vermehren

Sauer

et al. 2011

J Histochem Cytochem.

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The importance of using techniques that allow the study of pure populations of cells has been increasingly recognized. The authors used laser-assisted microdissection (LAM) in combination with quantitative real-time PCR (qPCR) to assess the relative expression of mRNAs encoding estrogen receptor α (ERα) and progesterone receptor (PR) in the different compartments of the bovine oviduct (epithelium, stroma, smooth muscle coat) during the follicular and mid-luteal phases of the estrus cycle. The localization of receptor mRNA was further studied using non-radioactive in situ hybridization (NISH). A special focus was on whether formalin fixation and paraffin embedding influence the quality and quantity of mRNA obtained from microdissected material. Distinct cyclic changes of the mRNA in the bovine oviduct were observed with elevated levels of PR mRNA transcripts in the epithelium and smooth muscle coat during the follicular phase. The expression of PR mRNA did not vary significantly in the stroma of the bovine oviduct during follicular and mid-luteal phases. In conclusion, the authors found that LAM with qPCR can precisely locate and accurately quantify mRNA expression in specific cell populations from formalin-fixed and paraffin-embedded oviductal tissue.

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“…that prenatal T treatment compromises oocyte quality [27]. Earlier studies have found that a delay in LH surge of 11.4 h in heifers [28] and 24-48 h in mice [29,30] reduces fertilization and implantation rates and increases embryonic death and chromosome abnormalities [28][29][30]. In superovulation models of cattle, a delayed surge of 24-48 h was found to be associated with compromised follicular development [31], decreased ovulation rate, and lowered rate of embryo production [32].…”

Section: Consequences Of Delayed Lh Surgementioning

confidence: 99%

Fetal Programming: Testosterone Exposure of the Female Sheep During Midgestation Disrupts the Dynamics of Its Adult Gonadotropin Secretion During the Periovulatory Period1

Savabieasfahani¹,

Lee²,

Herkimer³

et al. 2005

Biology of Reproduction

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Prenatal exposure of the female sheep to excess testosterone (T) leads to hypergonadotropism, multifollicular ovaries, and progressive loss of reproductive cycles. We have determined that prenatal T treatment delays the latency of the estradiol (E2)-induced LH surge. To extend this finding into a natural physiological context, the present study was conducted to determine if the malprogrammed surge mechanism alters the reproductive cycle. Specifically, we wished to determine if prenatal T treatment 1) delays the onset of the preovulatory gonadotropin surge during the natural follicular phase rise in E2, 2) alters pulsatile LH secretion and the dynamics of the secondary FSH surge, and 3) compromises the ensuing luteal function. Females prenatally T-treated from Day 60 to Day 90 of gestation (147 days is term) and control females were studied when they were approximately 2.5 yr of age. Reproductive cycles of control and prenatally T-treated females were synchronized with PGF2alpha, and peripheral blood samples were collected every 2 h for 120 h to characterize cyclic changes in E2, LH, and FSH and then daily for 14 days to monitor changes in luteal progesterone. To assess LH pulse patterns, blood samples were also collected frequently (each 5 min for 6 h) during the follicular and luteal phases of the cycle. The results revealed that, in prenatally T-treated females, 1) the preovulatory increase in E2 was normal; 2) the latencies between the preovulatory increase in E2 and the peaks of the primary LH and FSH surges were longer, but the magnitudes similar; 3) follicular-phase LH pulse frequency was increased; 4) the interval between the primary and secondary FSH surges was reduced but there was a tendency for an increase in duration of the secondary FSH surge; but 5) luteal progesterone patterns were in general unaltered. Thus, exposure of the female to excess T before birth produces perturbances and maltiming in periovulatory gonadotropin secretory dynamics, but these do not produce apparent defects in cycle regularity or luteal function. To reveal the pathologies that lead to the eventual subfertility arising from excess T exposure during midgestation, studies at older ages must be conducted to assess if there is progressive disruption of neuroendocrine and ovarian function.

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Effects of brief postponement of the preovulatory LH surge on ovulation rates and embryo formation in eCG/prostaglandin-treated heifers

Cited by 28 publications

References 36 publications

FSH withdrawal improves developmental competence of oocytes in the bovine model

FSH withdrawal improves developmental competence of oocytes in the bovine model

Cellular Expression and Localization of Estrogen Receptor α and Progesterone Receptor mRNA in the Bovine Oviduct Combining Laser-Assisted Microdissection, Quantitative PCR, and In Situ Hybridization

Fetal Programming: Testosterone Exposure of the Female Sheep During Midgestation Disrupts the Dynamics of Its Adult Gonadotropin Secretion During the Periovulatory Period1

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