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PubMed1987

Effect of mouse epidermal growth factor on plasma concentrations of FSH, LH and progesterone and on oestrus, ovulation and ovulation rate in merino ewes.

The 24 h i.v. infusion of Merino ewes with 60 or 100 microgram mouse epidermal growth factor (EGF)/kg body weight on Days 4, 9 or 14 of the oestrous cycle decreased the strength of wool attachment and caused marked changes in subsequent reproductive performance. In ovaries removed 2 days after EGF treatment all follicles greater than or equal to 0.6 mm diameter were atretic. After 7 days either a normal pattern of atresia or no atresia was evident while after 12 days the pattern of follicular atresia was similar to that in controls. Irrespective of stage of cycle EGF caused dose-dependent increases in plasma FSH concentrations that persisted for up to 14 days. Changes in plasma LH concentrations were generally similar after infusion on Days 4 and 14, but were smaller and shorter-lived after infusion on Day 9. Irrespective of dose, the infusion of EGF on Days 4 and 14 caused immediate luteolysis then the formation of a luteinized follicle in many ewes. Most ewes treated on Day 4 returned to oestrus between Days 17 and 21 with the same ovulation rate (1.3) as the controls. Of those infused on Day 14 oestrus occurred about a cycle length later than expected and their ovulation rate then (1.9) was also similar to that of the controls (1.7). Luteal function was not affected in ewes infused on Day 9, and most returned to oestrus between Days 17 and 20 with an ovulation rate of 3.2. Fertile rams were not placed with the ewes until after the differences in ovulation rate had been observed. Mating occurred generally 2-4 weeks after treatment, and there were no differences between EGF-treated and control ewes in fertility or fecundity. The results are interpreted as indicating that mouse EGF induces ovarian follicular atresia but has differential effects on luteal function according to the stage of the oestrous cycle at which it is given. As a consequence of these two effects, which lead to differential changes in gonadotrophin secretion, ovarian function may be temporarily impaired, little affected or improved.

Animals↗
PubMed2002

Comparative changes in plasma concentrations of progesterone, oestradiol and LH during the ovulatory cycle in a multiple ovulating male line and a single ovulating traditional line of turkeys.

The aim of this study was to compare the profile of circulating concentrations of LH, progesterone and oestradiol in a multiple ovulating male line with that of a single ovulating line of traditional turkeys. Plasma samples from seven traditional and 12 male-line turkeys were obtained every 3 h for 36 h. Male-line and traditional turkeys had single peaks of LH and progesterone that were of similar duration in both lines. The mean height of the plasma peaks of LH and progesterone were similar in the two lines and there was no detectable peak plasma oestrogen concentration. Mean plasma concentrations of LH and oestrogen were higher in single compared with multiple ovulating turkeys, whereas there were no differences in mean plasma progesterone concentrations. The results indicate that the multiple ovulation state in genetically selected high-growth lines of turkey may be the result of a correlated response in the steroidogenic capacity of ovarian tissue associated with low plasma concentrations of oestrogen rather than of a disturbance in the hormone profile of the ovulatory cycle.

Animals↗
PubMed1997

Recurrent molar pregnancy after ovulation induction and repeat ovulation induction. A case report.

BACKGROUND: Although hydatidiform mole is not commonly encountered following ovulation induction, patients who have already had molar pregnancies are at increased risk of developing further molar diseases with worsening histologic characteristics. That fact underlies the ethical dilemma of repeat ovulation induction. CASE: A 38-year-old woman, gravida 3, para 0, had three consecutive episodes of hydatidiform subsequent to clomiphene citrate and gonadotropin ovulation induction. She seems to be the first in the literature to develop three consecutive molar pregnancies without a normal intrauterine pregnancy. CONCLUSION: Although ovulation induction commenced again in this patient after she gave informed consent, the risks underlying the ethical dilemma persist.

Adult↗
PubMed2005

Environmental stress alters genes expression and induces ovule abortion: reactive oxygen species appear as ovules commit to abort.

Environmental stress dramatically reduces plant reproduction. Previous results showed that placing roots in 200 mM NaCl for 12 h caused 90% of the developing Arabidopsis ovules to abort (Sun et al. in Plant Physiol 135:2358-2367, 2004). To discover the molecular responses that occur during ovule abortion, gene expression was monitored using Affymetrix 24k genome arrays. Transcript levels were measured in pistils that were stressed for 6, 12, 18, and 24 h, then compared with the levels in healthy pistils. Over the course of this experiment, a total of 535 salt-responsive genes were identified. Cluster analysis showed that differentially expressed genes exhibited reproducible changes in expression. The expression of 65 transcription factors, some of which are known to be involved in stress responses, were modulated during ovule abortion. In flowers, salt stress led to a 30-fold increase in Na+ ions and modest, but significant, decreases in the accumulation of other ions. The expression of cation exchangers and ion transporters were induced, presumably to reestablish ion homeostasis following salt stress. Genes that encode enzymes that detoxify reactive oxygen species (ROS), including ascorbate peroxidase and peroxidase, were downregulated after ovules committed to abort. These changes in gene expression coincided with the synthesis of ROS in female gametophytes. One day after salt stress, ROS spread from the gametophytes to the maternal chalaza and integuments. In addition, genes encoding proteins that regulate ethylene responses, including ethylene biosynthesis, ethylene signal transduction and ethylene-responsive transcription factors, were upregulated after stress. Hypotheses are proposed on the basis of this expression analysis, which will be evaluated further in future experiments.

Arabidopsis↗
PubMed1981

Limited multiple ovulation in heifers fed high plane of nutrition before PMSG stimulation and steroid hormone concentrations in single, twin and multiple ovulators.

Limited multiple ovulation (2-4 CL's) in heifers was attempted by feeding a low or a high plane of nutrition during an estrous cycle and injecting a low dose of PMSG at day 16 of that cycle. Multiple ovulation was achieved in 52% of the 19 dairy x beef crossbred heifers that received 1200 I.U. of PMSG. The ratio of the number of heifers which ovulated between 2-4 follicles to those ovulating 1 and more than 4 was higher (P<0.05) in heifers which were fed a high plane of nutrition than in those which were fed a low plane of nutrition. Thirty-six hours after the PMSG injection and prior to estrus, the concentration of E(2)-17beta was less in heifers with 1 growing follicle developing into 1 CL than in heifers with 2 or >2 growing follicles developing into CL's (P<0.01). Heifers with >2 growing follicles developing into CL's had more E(2)-17beta than those which eventually formed 2 CL's (P<0.01). Moreover, in heifers with >2 CL, E(2)-17beta concentration increased regularly until at least 96 hrs after the PMSG injection, while in heifers with 1 CL or 2 CL's, the concentration plateaued at 60 hrs after the PMSG injection. Progesterone concentration during proestrus was lower in heifers that developed >2 CL's than in those with 1 or 2 CL's (P<0.05).

Journal Article↗
PubMed1988

Physiological mechanisms associated with ovulation prediction using the CUE Ovulation Predictor.

It has been shown that monitoring of salivary electrical resistance (SR) enables prediction of ovulation several days in advance, since a peak in SR is seen 5-6 days before the LH peak. This paper explores physiological mechanisms that may account for this change. The pathway whereby oestrogen stimulates aldosterone (ALDO) secretion acting through the renin-angiotensin system was considered. It is shown that this mechanism would only result in increasing SR as oestrogen values rise during the follicular phase and therefore is not an explanation of the SR peak and declining SR 5-6 days before the LH peak. The reported trend of sodium in milk of ovulating women parallels that of SR. It is shown that these changes are most likely to be due to a similar change in aldosterone levels. A possible role for adrenocorticotrophic hormone (ACTH) in causing the changes in aldosterone is discussed and supported with data from other independent studies as well as with preliminary data obtained from two normally ovulating subjects. Peaks in ACTH, ALDO and SR were coincidental and occurred 6 days before the LH peak. The temporal relationship observed among these variables suggest that ACTH, by affecting ALDO, modifies salivary electrolytes and hence SR.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Prediction and detection of ovulation relationship between woman's observations of cervical mucus changes, thermic and echographic parameters of ovulation.

Every woman can perceive and interpret her fertility signs such as cyclic changes of cervical mucus, sensation of wetness and lubrification of the vulva and thermal shift. 18 cycles were studied in 6 volunteers but one cycle was eliminated because ovulation did not occur. Each of the 6 women perceived the day in which cervical mucus was more abundant, clear, lubrificative and elastic and noted the "Peak" mucus day. These two data were correlated with the thermic nadir day and the day or the period of echographic ovulation showing an accurate relationship with ovulation.

Adult↗
PubMed2001

Ovarian steroid hormone production in a multiple ovulating male line and a single ovulating traditional line of turkeys.

Ovarian production of oestradiol and progesterone was investigated in a single ovulating traditional line and a multiple ovulating male line of turkeys. The oestradiol output from small follicles in response to LH stimulation and the aromatase activity of the residual ovary were also compared. The multiple hierarchy of follicles in the male line was shown to consist of a series of follicles of a similar size and stage of physiological maturation. The follicles of the traditional line produced significantly greater quantities of oestradiol than those of the male line. Impaired oestradiol production may have resulted in the lower plasma oestradiol concentration observed in the male line. There was no difference in follicular progesterone output between the traditional-line and male-line turkeys. The oestradiol output of whole small white follicles in response to LH stimulation was similar in the two lines and the depressed steroidogenesis of the male line was not changed. The aromatase activity of the small follicles was also lower in the male line, and there was no evidence that the male line ovary produced oestradiol in quantities proportional to its size. The results demonstrated that the hierarchy of follicles in the male line consisted of groups of follicles of similar mass and hormone output and indicated that selection for increased meat yield may have resulted in reduced ovarian steroidogenesis in male-line turkeys, in comparison with traditional, unselected turkeys.

Animals↗
PubMed1995

The luteinizing hormone surge--the final stage in ovulation induction: modern aspects of ovulation triggering.

OBJECTIVE: To compile updated information regarding gonadotropin secretion, specifically the physiology of the midcycle LH surge, in natural cycles and under various ovulation induction protocols. DATA IDENTIFICATION AND SELECTION: Studies that deal with the clinical aspects of LH surge manipulation or substitution were identified through literature and Medline searches. RESULTS: Three major regulatory factors have been identified as participants in the induction of the midcycle gonadotropin surge. These are hypothalamic GnRH secretion, ovarian and adrenal steroids, and less well-characterized ovarian peptide hormones. Gonadotropin-releasing hormone pulsatility is regulated by a complex mechanism that integrates multiple neurotransmitters and sex steroids. Estradiol plays a central role in the pituitary secretion of LH, which also is influenced by P concentrations. Gonadotropin surge attenuating factor also has been implicated in the regulation of timing and amplitude of the LH surge. Human chorionic gonadotropin is used extensively as a LH surrogate, but its use is associated with a number of disadvantages. Induction of an endogenous LH surge through use of the flare effect of GnRH analogues has been examined more recently and has been found to have several advantages. Recombinant human LH is in the final stages of clinical testing. CONCLUSION: Although much is known about the physiology of the midcycle LH surge and its variations under different clinical conditions, new approaches to the induction or substitution of the LH surge currently are being examined and learned. The introduction of recombinant gonadotropins into clinical practice is likely to influence ovulation induction and IVF practice to a significant degree in the near future.

Chorionic Gonadotropin↗
PubMed2006

Gene expression profiles of cumulus cell oocyte complexes during ovulation reveal cumulus cells express neuronal and immune-related genes: does this expand their role in the ovulation process?

Ovulation is a complex process initiated by the preovulatory LH surge, characterized by cumulus oocyte complex (COC) expansion and completed by the release of a mature oocyte. Although many ovarian genes that impact ovulation have been identified, we hypothesized that genes selectively expressed in COCs would be overlooked by approaches using whole ovary or granulosa cell samples. RNA isolated from COCs collected from preovulatory follicles of equine chorionic gonadotropin (CG) primed mice and at selected times after human CG treatment was subjected to microarray analyses and results confirmed by RT-PCR analyses, Western blotting, and immunofluorescent studies. A remarkable number of genes were up-regulated in COCs including Areg, Ereg, and Btc. Several genes selectively expressed in cumulus cells compared with granulosa cells were related to neuronal (Mbp, Tnc, Nts) or immune (Alcam, Pdcd1, Cd34, Cd52, and Cxcr4) cell function. In addition to Sfrp2, other members of the Wnt/Fzd family (Sfrp4, Fdz1 and Fdz2) were expressed in COCs. Thus, there is a cumulus cell-specific, terminal differentiation process. Furthermore, immunofluorescent analyses documented that cumulus cells are highly mitotic for 4-8 h after human CG and then cease dividing in association with reduced levels of Ccnd2 mRNA. Other down-regulated genes included: Cyp19a1, Fshr, Inhb, and the oocyte factors Zp1-3 and Gja4. In summary, the vast number of matrix, neuronal, and especially immune cell-related genes identified by the gene- profiling data of COCs constitutes strong and novel evidence that cumulus cells possess a repertoire of immune functions that could be far greater than simply mediating an inflammatory-like response.

Animals↗
PubMed1986

Use of bovine follicular fluid to increase ovulation rate or prevent ovulation in sheep.

Romney ewes were injected intramuscularly once or twice daily for 3 days with 0, 0.1, 0.5, 1 or 5 ml of bovine follicular fluid (bFF) treated with dextran-coated charcoal, starting immediately after injection of cloprostenol to initiate luteolysis on Day 10 of the oestrous cycle. There was a dose-related suppression of plasma concentrations of FSH, but not LH, during the treatment period. On stopping the bFF treatment, plasma FSH concentrations 'rebounded' to levels up to 3-fold higher than pretreatment values. The mean time to the onset of oestrus was also increased in a dose-related manner by up to 11 days. The mean ovulation rates of ewes receiving 1.0 ml bFF twice daily (1.9 +/- 0.2 ovulations/ewe, mean +/- s.e.m. for N = 34) or 5.0 ml once daily (2.0 +/- 0.2 ovulations/ewe, N = 25) were significantly higher than that of control ewes (1.4 +/- 0.1 ovulations/ewe, N = 35). Comparison of the ovaries of ewes treated with bFF for 24 or 48 h with the ovaries of control ewes revealed no differences in the number or size distribution of antral follicles. However, the large follicles (greater than or equal to 5 mm diam.) of bFF-treated ewes had lower concentrations of oestradiol-17 beta in follicular fluid, contained fewer granulosa cells and the granulosa cells had a reduced capacity to aromatize testosterone to oestradiol-17 beta and produce cyclic AMP when challenged with FSH or LH. No significant effects of bFF treatment were observed in small (1-2.5 mm diam.) or medium (3-4.5 mm diam.) sized follicles. Ewes receiving 5 ml bFF once daily for 27 days, from the onset of luteolysis, were rendered infertile during this treatment period. Oestrus was not observed and ovulation did not occur. Median concentrations of plasma FSH fell to 20% of pretreatment values within 2 days. Thereafter they gradually rose over the next 8 days to reach 60% of pretreatment values where they remained for the rest of the 27-day treatment period. Median concentrations of plasma LH increased during the treatment period to levels up to 6-fold higher than pretreatment values. When bFF treatment was stopped, plasma concentrations of FSH and LH quickly returned to control levels, and oestrus was observed within 2 weeks. The ewes were mated at this first oestrus and each subsequently delivered a single lamb.

Animals↗
PubMed1989

[Significance of HCG injection for ovulation induction and of ovulation prediction factors in the practice of artificial insemination using donor sperm. A randomized study].

This randomised study was carried out on 77 patients who underwent 269 cycles of donor insemination (AID). The randomization was carried out to decide whether HCG should be used or not to provoke ovulation. The results in AID show, in our study, that using HCG in estimating oestradiol makes very little difference. On the other hand, measuring LH and the quality of the sperm that is used for the insemination seem to us to be important, whereas the quality of the cervical mucus is absolutely fundamental. Ultrasound makes it possible to determine the date when the AID should be carried out in difficult cases. The use of HCG to release the oocytes can be discussed when the cervical score is less than 7 when the other parameters are favourable, and in particular when the diameter of the dominant follicle is 18 mm or more. A higher pregnancy rate should be able to be obtained in AID if all parameters are looked at.

Chorionic Gonadotropin↗
PubMed1992

A comparison of ovulation suppression and ovulation stimulation in the treatment of endometriosis-associated infertility.

This study compares ovulation stimulation or suppression with the pregnancy rate among infertile couples with endometriosis. The design is a nonrandomized, prospective, multicentered cohort analytic study. Two hundred and ninety-seven couples with laparoscopy-proven endometriosis were analyzed: 68 received no therapy, 42 received clomiphene and 74 received danazol. Forty patients (22%) conceived and pregnancy rates were similar in each treatment group. The relative likelihood of pregnancy associated with clomiphene was 2.9 (95% confidence limits 1.2-7.1); the relative likelihood of pregnancy with danazol was 1.02 (95% confidence limits 0.5-2.3). This study suggests that pregnancy rates during clomiphene treatment could be superior to expectant therapy, while pregnancy rate after danazol is similar to no treatment.

Adult↗
PubMed1996

Ovulation and post-ovulation changes in the terminal region of the ovarioles of the mosquito Aedes aegypti (L.) (Diptera: Culicidae).

Detachment of the follicular epithelium from the chorion occurs prior to the passage of the mature egg into the calyx lumen, resulting in a mature oocyte lying free in an epithelial sac. The mature oocytes rupture the epithelial sac, including the tunica propria at the posterior pole, then break through the basal (or granular basal) bodies to enter the calyx lumen. Just after ovulation, the formerly terminal parts of the ovariole remain attached to the posterior end of the egg sac near its opening. The terminal parts then undergo changes in conjunction with complete degeneration of the egg sac and development of the basal body. They cannot be used for age determination of females.

Aedes↗
PubMed1991

[Estrus and ovulation synchronization in Merino meat sheep. 2. Fertility outcome after estrus and ovulation synchronization with Cloprostenol "Jenapharm" and Gonovet "Berlin-Chemie" and term-oriented artificial insemination].

49 of 102 sheep of one production herd, which had returned to oestrus once or twice within the 1985 breeding season, were treated twice in a nine-day interval with the PGF2 alpha analogue Cloprostenol "Jenapharm". 53 animals received an additional dose of 10 micrograms of Gonavet "Berlin-Chemie". A lambing rate of merely 15% was achieved by subsequent term-oriented artificial insemination. 31 sheep still in oestrus one day after term-oriented artificial insemination were served, bringing the lambing rate from synchronisation of oestrus and ovulation to 26% and the lambing result to 154%. Serving of the remaining sheep in 2 subsequent oestric cycles, on balance, yielded lambing rates and results of the remaining sheep in 2 subsequent oestric cycles, on balance, yielded lambing rates and results which were higher with significance than those recorded from untreated sheep in the same herd.

Animals↗