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PubMed2006

Similar ovulation rates, but different follicular development with highly purified menotrophin compared with recombinant FSH in WHO Group II anovulatory infertility: a randomized controlled study.

BACKGROUND: The contribution of the LH activity in menotrophin preparations for ovulation induction has been investigated in small trials conducted versus FSH preparations. The objective of this study was to demonstrate non-inferiority of highly purified urinary menotrophin (HP-HMG) versus recombinant FSH (rFSH) with respect to the primary outcome measure, ovulation rate. METHODS: This was a randomized, open-label, assessor-blind, multinational study. Women with anovulatory infertility WHO Group II and resistant to clomiphene citrate were randomized (computer-generated list) to stimulation with HP-HMG (n=91) or rFSH (n=93) using a low-dose step-up protocol. RESULTS: The ovulation rate was 85.7% with HP-HMG and 85.5% with rFSH (per-protocol population), and non-inferiority was demonstrated. Significantly fewer intermediate-sized follicles were observed in the HP-HMG group (P<0.05). The singleton live birth rate was comparable between the two groups. The frequency of ovarian hyperstimulation syndrome and/or cancellation due to excessive response was 2.2% with HP-HMG and 9.8% with rFSH (P=0.058). CONCLUSIONS: Stimulation with HP-HMG is associated with ovulation rates at least as good as a rFSH in anovulatory WHO Group II women. LH activity modifies follicular development so that fewer intermediate-sized follicles develop. This could have a positive impact on the safety of ovulation induction protocols.

Adolescent↗
PubMed2006

Gelatinases and their tissue inhibitors during human ovulation: increased expression of tissue inhibitor of matrix metalloproteinase-1.

Remodelling of the extracellular matrix (ECM) of the follicular wall by matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) has been suggested to be crucial in ovulation. To investigate the expression of the gelatinases, MMP-2 and MMP-9, together with their inhibitors, TIMP-2 and TIMP-1, in the perifollicular ovarian stroma from women just before and during ovulation, we obtained biopsies of the stroma adjacent to the leading follicle. Laparoscopic surgery was performed either before the LH peak or at any of three intervals after ovulation triggering by hCG. Immunoblotting, immunohistochemistry and quantitative RT-PCR were performed. All four proteins were expressed by immunoblots, with no detectable changes in the expression of MMP-2, MMP-9 and TIMP-2. Scattered immunostaining for MMP-9 and TIMP-2 was seen, and MMP-2 was demonstrated in a concentric layer. A significant increase in TIMP-1 protein and mRNA was seen during the three ovulatory phases, and a strong and patchy immunostaining for TIMP-1 was shown. This is the first study that has demonstrated an ovulation-associated expression of these ECM-remodelling enzymes around the human follicle at ovulation. The increased expression of TIMP-1 may reflect a specific temporal inhibition of collagenolysis and thereby a time-dependent regulation of ECM breakdown in areas surrounding the apex of the follicle.

Adult↗
PubMed1996

Symmetry and ovulation in women.

Women have cryptic ovulation, and self-observation methods of determining the timing of ovulation, such as monitoring cervical mucus symptoms or recording basal body temperature, are not reliable. It has recently become apparent that the symmetry of paired soft tissue traits, such as breast size and digit length, changes across the menstrual cycle. This paper presents evidence that symmetry in four paired soft tissue traits showed a marked increase on the day of ovulation. The difference (i.e. the asymmetry) between the size of the left and right trait in ears, 3rd, 4th and 5th digits was measured. The timing of ovulation was confirmed by real-time pelvic ultrasonography and trait measurements were made without knowledge of scan results. Asymmetry was lowest on the day of ovulation (day 0), decreasing by about 30% from day -1, and significant within-subjects changes occurred from days -2 to day -1, and day -1 to day 0. The practical and evolutionary implications of these findings are discussed.

Adult↗
PubMed2005

Conditional induction of ovulation in mice.

Follicle-stimulating hormone controls the maturation of mammalian ovarian follicles. In excess, it can increase ovulation (egg production). Reported here is a transgenic doxycycline-activated switch, tested in mice, that produced more FSHB subunit (therefore more FSH) and increased ovulation by the simple feeding of doxycycline (Dox). The transgenic switch was expressed selectively in pituitary gonadotropes and was designed to enhance normal expression of FSH when exposed to Dox, but to be regulated by all the hormones that normally control FSH production in vivo. Feeding maximally effective levels of Dox increased overall mRNA for FSHB and serum FSH by over half in males, and Dox treatment more than doubled the normal ovulation rate of female mice for up to 10 reproductive cycles. Lower levels of Dox increased the number of developing embryos by 30%. Ovarian structure and function appeared normal. In summary, gene switch technology and normal FSH regulation were combined to effectively enhance ovulation in mice. Theoretically, the same strategy can be used with any genetic switch to increase ovulation (or any highly conserved physiology) in any mammal.

Animals↗
PubMed1983

Ovulation and fertilization in the vole, Pitymys subterraneus.

The females of Pitymys subterraneus bred in laboratory conditions have an irregular sexual cycle and induced ovulation. The first freshly ovulated eggs, surrounded by dense cumulus cells, appear in oviducts 10 h after copulation. Administering exogenous gonadotropins: pregnant mare's serum (PMS), human chorionic gonadotropin (hCG) or luteinizing hormone releasing hormone (LHRH), also induces ovulation in mature females of Pitymys subterraneus. In these experimental conditions females ovulate a similar number of eggs as after copulation. Dual stimulation (PMS and hCG plus copulation) does not result in the ovulation of a large number of normal ova, however, it does cause a release of degenerated oocytes.

Animals↗
PubMed1987

Gonadotropin-releasing hormone treatment induces follicular growth and ovulation in seasonally anestrous mares.

A study was conducted to evaluate the effectiveness of gonadotropin-releasing hormone (GnRH) pulse infusion to stimulate follicular development and induce ovulation in seasonally anestrous standardbred mares. Seventeen mares were selected for use in this experiment, on the basis of a previous normal reproductive history, and were housed under a photoperiod of 8L:16D beginning one week prior to the start of the experiment (second week in January). Mares were infused with 20 micrograms (n = 7) or 2 micrograms (n = 6) GnRH/h, or were subjected to photoperiod treatment only (controls, n = 4). Serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and progesterone did not vary, and neither significant follicular development nor ovulation was observed in any control mare throughout the experimental period (greater than 60 days). By contrast, both groups of GnRH-treated mares showed elevated serum concentrations of LH and FSH within one day after the start of infusion. Mares infused with 20 micrograms GnRH/h had at least one follicle greater than or equal to 25 mm in 7.4 +/- 1.3 (mean +/- SEM) days following the start of infusion, and ovulated in 12.0 +/- 0.7 days. In the 2-microgram-GnRH/h treatment group, a 25-mm follicle was detected in 5.7 +/- 0.7 days, and ovulation occurred after 10.0 +/- 0.3 days of infusion. Ovulation in every instance was followed by a functional luteal phase, as indicated by the profiles of progesterone secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Anestrus↗
PubMed1992

Characterization of the kinin system in the ovary during ovulation in the rat.

Ovulation has been noted for some time to bear a remarkable similarity to an inflammatory response. One of the principal components that is activated and helps mediate the events during an inflammatory response is the kinin system. Therefore, the purpose of the present study was to examine whether this system could be similarly activated and involved in the cascade of events that leads to ovulation. To answer this question, immature 23-day-old female rats were primed with eCG (10 IU) and ovulation was induced by administration of hCG (10 IU) 48 h later. Groups of rats were killed at 0 h, 10 h, 20 h, and 30 h after hCG for determination of ovulation, ovarian steroid levels, and changes in the levels of kinin system components. Plasma total kininogen levels did not change during the entire period studied. In contrast, ovarian total kininogen levels rose from 0 h to reach a peak at 10 h--a time immediately preceding the beginning of ovulation--after which the levels fell at 20 h, only to rise again at 30 h. Three species of kininogens, high molecular weight (HMW), low molecular weight (LMW), and T-kininogen, were shown to be present in the ovary. T-kininogen was the major kininogen present in the ovary, accounting for 60-92% of the total kininogen at any given time point during the ovulatory process. HMW kininogen levels accounted for only 1.2% of the total ovarian kininogen.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1978

Ovulation and pregnancy rates with clomiphene citrate.

A review of recent experience with clomiphene citrate at the Yale-New Haven Medical Center yields the following conclusions: 1) Clomiphene citrate administered at high doses (150 mg and 200 mg) is effective in inducing ovulation in women who would otherwise have failed to conceive if treatment were restricted to only lower dosage regimens. 2) Therapy with clomiphene citrate should be initiated with the 50-mg dose. The 100-mg dose should be reserved for those who fail with the lower dose. 3) Children resulting from clomiphene-induced ovulations appear to be developing normally both mentally and physically. Congenital malformations found in children from clomiphene-induced pregnancies are those seen commonly in general obstetric practice resulting in no significant problems for the children. 4) After 3 ovulations with clomiphene citrate approximately 50% of the patients can be expected to conceive. A 50% conception rate after 3 ovulations with clomiphene citrate does not represent a discrepancy between ovulation rates and pregnancy results, for it agrees statistically with the results obtained for the general population.

Abnormalities, Drug-Induced↗
PubMed1999

Regulation and localization of matrix metalloproteinases and tissue inhibitors of metalloproteinases in the mouse ovary during gonadotropin-induced ovulation.

At the time of ovulation, proteolytic degradation of the follicular wall is required to release the mature oocyte. Extracellular proteases, such as serine proteases and matrix metalloproteinases (MMPs), are thought to play important roles in this process. In this study we have examined the regulation of 11 MMPs and 3 tissue inhibitors of metalloproteinases (TIMPs) during gonadotropin-induced ovulation in the mouse. Northern blot hybridization showed that messenger RNA for several MMPs and TIMPs, including gelatinase A, MT1-MMP, stromelysin-3, MMP-19, TIMP-1, TIMP-2, and TIMP-3, were present at detectable levels in the mouse ovary. In addition, ovarian extracts contained gelatinolytic activities corresponding to the inactive proforms of gelatinase A and gelatinase B. Most of the MMPs and TIMPs were expressed at a constitutive level throughout the periovulatory period. However, MMP-19 and TIMP-1 revealed a different expression pattern; they were both induced 5-10 times by hCG and reached their maximum levels at 12 h after hCG treatment, corresponding to the time of ovulation. At this time point, MMP-19 and TIMP-1 messenger RNA were localized to the granulosa and thecal-interstitial cells of large preovulatory and ovulating follicles. This temporal and spatial regulation pattern suggests that MMP-19 might be involved in the tissue degradation that occurs during follicular rupture and that TIMP-1 could have a role in terminating MMP activity after ovulation.

Animals↗
PubMed1992

Ovulation induction with a single-blind treatment regimen comparing naltrexone, placebo and clomiphene citrate in women with secondary amenorrhea.

Secondary amenorrhea is often associated with emotional stress, weight loss, eating disorders or polycystic ovary-like disease. Involvement of the endogenous opioids in the pathophysiology of hypothalamic amenorrhea, by inhibition of hypothalamic GnRH secretion, has been demonstrated in some cases. Chronic blockade of the endogenous opioids with the long-acting opioid antagonist naltrexone could result in increased gonadotropin secretion and ovulation induction in these cases. A single-blind ovulation induction protocol comparing naltrexone, placebo and clomiphene citrate was evaluated in eight patients with secondary amenorrhea. Naltrexone proved not to be more effective than placebo in our study. Only one patient ovulated on naltrexone, one on placebo and four on clomiphene citrate. The latter therapy caused a better endocrine response. In conclusion, although ovulation could be incidentally induced by naltrexone, this drug did not appear to be more successful than placebo and clomiphene citrate for ovulation induction in this population of patients.

Amenorrhea↗
PubMed1985

Involvement of local adrenergic receptors in the process of ovulation in gonadotrophin-primed immature rats.

Immature female rats were primed with 4 i.u. PMSG at 08:00 h of Day 26. This results in ovulation in the morning of Day 29. The number of ovulations was counted in terms of newly formed corpora lutea in the morning of Day 30. Various adrenergic drugs were delivered into the ovarian bursa bilaterally in the afternoon of Day 27 to study their effect on ovulation. A methyl cellulose gel solution was used as vehicle to minimize leakage from the bursa. Noradrenaline, terbutaline and 4-aminopyridine significantly enhanced the number of corpora lutea compared to control ovaries injected with gel vehicle alone. The effect of terbutaline was counteracted by propranolol. Phentolamine partly blocked the noradrenaline-induced enhancement and the antagonist alone significantly reduced the number of ovulations. The results indicate that stimulation of alpha-adrenergic receptors (probably via actions in the follicle wall) as well as beta-receptors (influencing steroid-producing cells) may interfere with the ovulation process.

4-Aminopyridine↗
PubMed1988

Time of ovulation in goats (Capra hircus) induced to superovulate with PMSG.

The timing of ovulation in feral goats treated with 1200 i.u. PMSG +/- 50 micrograms GnRH was studied by repeated laparoscopy. Experiment 1 established that superovulation began as early as 30 h after withdrawal of progestagen-impregnated sponges and was not completed at 54 h if goats received PMSG alone. GnRH synchronized ovulation, leading to 91% of ovulations appearing between 36 and 48 h after sponges were withdrawn. Experiment 2 established that superovulation continued until up to 77 h in goats treated only with PMSG. The stress of repeated laparoscopy appeared to delay or abolish ovulation in some females. The mean (+/- s.e.) ovulation rate was greater in goats treated with GnRH (12.7 +/- 1.3) than in those that received PMSG only (9.7 +/- 1.1; P less than 0.05). Out of 47 of the females in Exp. 1, 43 had one or more corpora lutea at laparoscopy 24 h after withdrawal of progestagen. These early corpora lutea were associated with an increased concentration of plasma progesterone during the periovulatory period. Experiment 3 provided evidence that these corpora lutea arose before the withdrawal of progestagen-impregnated sponges.

Animals↗
PubMed1980

Inhibition by indomethacin of ovulation induced by human chorionic gonadotrophin in immature rats primed with pregnant mare serum gonadotrophin.

Treatment of immature rats with pregnant mare serum gonadotrophin followed by human chorionic gonadotrophin (HCG) caused an acute and temporary increase in concentrations of progesterone, testosterone and oestradiol in plasma with maximum levels 3 h after the administration of HCG. Concurrent injection of indomethacin and HCG reduced, in a dose-dependent manner, the mean number of ova shed and this was accompanied by a dose-dependent decrease in concentrations of plasma progesterone and testosterone but not of oestradiol when they were measured 3 h after the injection of HCG. The minimum effective dose that blocked ovulation completely at 0 h abolished the acute increase of progesterone and testosterone, suggesting that prostaglandins act on ovulation by stimulating steroidogenesis at an early stage in the preovulatory process. The anti-ovulatory action of the minimum effective dose at 0 h became progressively less potent as the time between injection of HCG and administration of indomethacin was increased, although plasma concentrations of progesterone and testosterone measured at autopsy 18 h after treatment with HCG had not changed appreciably. When indomethacin was administered 10 h after HCG, the relationship between the dose of indomethacin and the mean number of ova differed from that observed when simultaneous injections of indomethacin and HCG were given, and the minimum effective dose that prevented ovulation was much higher than that at 0 h, suggesting that prostaglandins act differently on ovulation in the later stage of the preovulatory process. It was concluded that prostaglandins may mediate the action of HCG on ovulation through two mechanisms which operate at different stages of the preovulatory process.

Animals↗
PubMed1980

Mechanism of the selective surge of follicle-stimulating hormone in dioestrous rats during the induction of ovulation by human chorionic gonadotrophin.

A selective surge of FSH with a small concomitant rise in LH occurred invariably in rats when ovulation was induced by injecting human chorionic gonadtrophin (HCG) at various reproductive stages such as day 15 of lactation and in 29-day-old immature rats as well as in dioestrous animals. No FSH surge occurred on day 3 of lactation or in 26-day-old immature rats in which ovulation could not be induced by HCG. The FSH surge occurred 6-18 h after HCG treatment regardless of the time of day of injection of HCG. Ovulation began by 12 h and was completed by 18 h after injection of HCG. Pituitary responsiveness to luteinizing hormone releasing hormone (LH-RH) with respect to FSH release strikingly incresed at 01.00 h on day 1 after HCG injection at 17.00 h of dioestrus (day 0) to levels similar to those of the group at 01.00 h of oestrus, when the greatest response was noted during the normal cycle. With regard to LH release pituitary responsiveness to LH-RH at 01.00 h on day 1 markedly increased but the response was only about half of the response at 01.00 h of oestrus and one third of the response at 17.00 h of pro-oestrus when the greatest response was noted during the normal oestrous cycle. These results indicate that during ovulation the pituitary gland of the rat is highly responsive to LH-RH with respect to the release of FSH, for which secretory changes in the ovary after an ovulating dose of HCG may be responsible.

Animals↗
PubMed2001

Effects of P.G. 600 on the onset of estrus and ovulation rate in gilts treated with Regu-mate.

Three experiments assessed the onset of estrus and ovulation rate in gilts treated with gonadotropins after the withdrawal of an orally active progestin. In Exp. 1, all cycling gilts received the progestin (Regu-mate; Intervet America Inc., Millsboro, DE) at a rate of 15 mg/d for 18 d. Twenty-four hours after the last feeding of Regu-mate, 32 gilts received an i.m. injection of 400 I.U. PMSG and 200 I.U. hCG (P.G. 600, Intervet America, Inc.), and 32 gilts received an i.m. injection of deionized water. The percentage of gilts displaying estrus < or = 7 d (P = 0.64) and the injection-to-estrus interval (P = 0.37) were similar for P.G. 600-treated gilts (93.8% and 4.1 +/- 0.1 d) and controls (90.6% and 4.3 +/- 0.1 d). Ovulation rate was greater (P < 0.01) in P.G. 600-treated gilts (28.8 +/- 1.1) compared with controls (17.4 +/- 1.1). In Exp. 2, 58 cycling gilts received Regu-mate (15 mg/d) for 18 d. Twenty-four hours after Regu-mate withdrawal, gilts received i.m. P.G. 600 or water (n = 29/treatment). Gilts were bred via AI 12 and 24 h after first detection of estrus. The percentage of gilts displaying estrus < or = 7 d (P = 0.45) and the injection-to-estrus interval (P = 0.27) were similar for P.G. 600-treated gilts (82.7% and 4.0 +/- 0.1 d) and controls (89.7% and 4.2 +/- 0.1 d). Ovulation rate was greater (P < 0.01) in P.G. 600-treated gilts (26.2 +/- 1.8) compared with controls (18.1 +/- 1.7). Pregnancy rate (P = 0.71) and the number of live embryos at d 30 postmating (P = 0.40) were similar for P.G. 600-treated gilts (91.7% and 15.6 +/- 1.2) and controls (88.5% and 14.1 +/- 1.2). In Exp. 3, prepubertal gilts (142.6 +/- 0.7 d of age) received Regumate (15 mg/d) (n = 20) or a control diet not including Regu-mate (n = 20) for 18 d. Twenty-four hours after Regu-mate withdrawal, all gilts received i.m. P.G. 600. The percentage of gilts displaying estrus < or = 7 d (P = 0.49) and the P.G. 600-to-estrus interval (P = 0.69) were similar for Regu-mate-fed gilts (95% and 4.3 +/- 0.2 d) and controls (88.9% and 4.2 +/- 0.2 d). Ovulation rate was similar (P = 0.38) for Regu-mate fed gilts (16.6 +/-1.6) and controls (14.4 +/- 1.8). In cycling gilts, administration of P.G. 600 after withdrawal of Regu-mate increased ovulation rate, but not litter size at d 30 postmating. There was no beneficial effect of Regu-mate pretreatment on the response to P.G. 600 in prepubertal gilts.

Animals↗
PubMed1976

"Timing" of ovulation by laparoscopy and evaluation of some physico-chemical parameters.

The Authors describe the laparoscopic aspects of spontaneous human ovulation and correlate it with the evaluation of basal body temperature, the total urinary oestrogens, pregnanediol and urinary LH and some hematic values of 17-beta-estradiol, 17-alpha-Hydroxyprogesterone and rogesterone. They find that the rise in temperature and the oestrogenuria peak precede ovulation by some hours in the great ovulation by sompe hours in the great majority of cases. They analyze the validity of the other parameters studied, and show a relatively constant behavior, with regard to ovulation, in the mean evaluation of several cases. In the individual analysis, on the contrary, this relation is difficult to find and less significant. The Authors stress the importance of comparing the physico-chemical evaluations with the biological phenomenon of ovulation directly ascertained by means of laparoscopy.

Body Temperature↗
PubMed1991

A comparative study on involvement of tPA activity in ovulation induced by hCG and GnRH agonist in hypophysectomized rats.

A GnRH agonist (5-50 micrograms) is capable of inducing ovulation in PMSG-primed hypophysectomized immature rats, as is the case in hCG-induced ovulation, but 2-4 h earlier than hCG. GnRH-induced ovulation is effectively blocked by the concomitant administration of the GnRH-antagonist which failed to interfere with hCG-induced ovulation, indicating that GnRH and its agonists do not share a receptor with LH/hCG. Like hCG, GnRH is also capable of inducing tissue type (tPA), but not urokinase type (uPA) PA. The plasminogen activator activity in ovarian homogenates and the granulosa and theca-interstitial cells increase in a time-dependent manner, reaching maximum levels just prior to ovulation. Similar to hCG, GnRH also increases tPA activity in cumulus-oocyte complexes in a time-dependent fashion.

Animals↗
PubMed1990

Milk and serum progesterone levels in mares after ovulation.

Twenty-four Finnhorse mares were examined by rectal palpation and ultrasonography every 6 h during late oestrus to determine the time of ovulation. Milk and serum samples were collected every 6 h after the detected ovulation for progesterone analysis. The progesterone rises took place within 0-54 h and 0-60 h after ovulation, in milk and serum, respectively. Statistically significant differences (p less than 0.05) in progesterone levels were observed for the first time 12-18 h and 18-24 h after ovulation, in serum and milk, respectively, as compared to progesterone levels 0-6 h after ovulation.

Animals↗