Exposing cultured mouse ovarian follicles under increased gonadotropin tonus to aromatizable androgens influences the steroid balance and reduces oocyte meiotic capacity

Acquisition of oocyte developmental competence relies on the well-controlled events accompanying antral follicular development. Elevated basal androgen levels, as in PCOS, potentially affect oocyte quality. Current experiments in an in vitro follicle bioassay studied dose-effects of androstenedione and testosterone on FSH and hCG stimulated antral follicle growth and meiotic maturation. The addition of either androgens altered follicle's endogenous production of androstenedione, testosterone, estradiol, and progesterone and affected the oocyte's capacity to resume meiosis. Exposure to 200?nM androstenedione induced an increased production of testosterone and estradiol. Exposure to a concentration of ≥200?nM testosterone induced elevated levels of estradiol and progesterone. Significant dose-dependent negative effects on polar body extrusion were seen at concentrations of ≥200?nM of either androgen. In addition, chromosome displacement on the metaphase plate was observed in oocytes obtained from androstenedione-treated follicles. Follicles exposed to a combination of 25?mIU/ml FSH and 3?mIU/ml hCG and elevated aromatizable androgens altered the steroid production profile, affected the follicular development and impaired oocyte meiotic competence.     

Midcycle administration of a progesterone synthesis inhibitor prevents ovulation in primates.

Progesterone receptors appear in granuloma cells of preovulatory follicles after the midcycle gonadotropin surge, suggesting important local actions of progesterone during ovulation in primates. Steroid reduction and replacement during the gonadotropin surge in macaques was used to evaluate the role of progesterone in the ovulatory process. Animals received gonadotropins to induce development of multiple preovulatory follicles, followed by human chorionic gonadotropin (hCG) administration (day 0) to promote oocyte (nuclear) maturation, ovulation, and follicular luteinization. On days 0-2, animals received no further treatment; a steroid synthesis inhibitor, trilostane (TRL); TRL + R5020; or TRL + dihydrotestosterone propionate (DHT). On day 3, ovulation was confirmed by counting ovulation sites and collecting oviductal oocytes. The meiotic status of oviductal and remaining follicular oocytes was evaluated. Peak serum estradiol levels, the total number of large follicles, and baseline serum progesterone levels at the time of hCG administration were similar in all animals. Ovulation sites and oviductal oocytes were routinely observed in controls. Ovulation was abolished in TRL. Progestin, but not androgen, replacement restored ovulation. Relative to controls, progesterone production was impaired for the first 6 days post-hCG in TRL, TRL + R5020, and TRL + DHT. Thereafter, progesterone remained low in TRL but recovered to control levels with progestin and androgen replacement. Similar percentages of mature (metaphase II) oocytes were collected among groups. Thus, steroid reduction during the gonadotropin surge inhibited ovulation and luteinization, but not reinitiation of oocyte meiotic maturation, in the primate follicle. The data are consistent with a local receptor-mediated role for progesterone in the ovulatory process.     

Administration of human luteinizing hormone (hLH) to macaques after follicular development: further titration of LH surge requirements for ovulatory changes in primate follicles.

After stimulation of multiple follicular development, endogenous LH surges elicited by GnRH or GnRH agonist were of insufficient duration (4-14 h) to evoke oocyte maturation and luteinization in this species. In this study, periovulatory LH surge requirements were further titrated using hLH as the ovulatory stimulus. Beginning at menses, rhesus monkeys were treated with human gonadotropins for 9 days to stimulate follicular growth. To induce ovulatory maturation on day 10, animals received: 1) hCG (1000 IU, im; n = 8); 2) highly-purified, urinary hLH (2542 IU, im; n = 4); or 3) hLH (2542 IU, im) followed by three injections of hLH (200 IU, im) at 8-h intervals (0800, 1600, 2400 h) daily during the luteal phase until menses (n = 3). Oocytes and luteinizing granulosa cells were obtained via follicle aspiration 27 h after the initial hLH or hCG injection. Estradiol and progesterone levels were measured in daily serum samples by RIA. Bioactive LH levels were determined at selected intervals within 36 h of the hLH ovulatory stimulus. Nuclear maturity of oocytes was evaluated as an indicator for reinitiation of meiosis. Luteinizing granulosa cells were processed for indirect immunocytochemistry using a monoclonal antibody to human progesterone receptor. In vitro progesterone production by luteinizing granulosa cells over 24 h was also assessed in the absence and presence of hCG. In all groups, serum estradiol rose to similar peak levels on day 10. After hLH, bioactive LH levels peaked (1262 +/- 79 ng/mL; mean +/- SEM) by 2-6 h, declined thereafter but remained above surge levels (100 ng/mL) for 18-24 h. Within 24 h of hLH injection, serum progesterone increased to 13 +/- 3 nmol/L, but returned to baseline in 1-6 days. In contrast, higher levels of progesterone were observed after hCG (114 +/- 51 nmol/L) and during luteal phase treatment with hLH (137 +/- 25 nmol/L) and the luteal phase was longer (11.5 +/- 0.4 and 14.3 +/- 0.7 days, respectively). Of the total cohort of oocytes aspirated, the proportion of oocytes resuming meiotic maturation (metaphase I plus metaphase II) was similar after hCG (76%) and hLH (74%). However, the proportion of oocytes maturing to metaphase II tended to be less (P = 0.08) after hLH (13%) than hCG (22%). Fertilization rates were similar between the two groups. Progesterone receptor was detected in nuclei of luteinizing granulosa cells from all animals receiving hCG, but only in some given hLH.(ABSTRACT TRUNCATED AT 400 WORDS)     

Use of gonadotropin-releasing hormone agonist to trigger follicular maturation for in vitro fertilization

In spontaneous cycles both LH and FSH are secreted in a surge at midcycle. In in vitro fertilization (IVF) cycles, hCG administration results in elevation of LH-like activity only. The objective of this study was to compare the effectiveness of a single midcycle dose of GnRH agonist with hCG on follicular maturation. Eighteen IVF cycles in 14 women were randomized to receive either 0.5 mg leuprolide acetate or 5000 IU hCG at midcycle. Both groups underwent identical ovarian stimulation and cycle monitoring. On the day of GnRH agonist or hCG administration, estradiol concentrations and the number of follicles 1.5 cm or larger were the same in both groups. Mean serum LH and FSH levels were elevated for 34 h after GnRH agonist administration. In contrast, mean serum hCG levels were elevated for approximately 6 days after the administration of hCG, and serum FSH levels did not change. Mean luteal phase serum estradiol concentrations were lower in the GnRH agonist group than in the hCG group (P less than 0.02). No differences were observed in mean serum progesterone or PRL during the luteal phase or in the length of the luteal phase in the two groups. The mean number of oocytes retrieved and embryo number and quality did not differ between the two groups. Three of nine GnRH agonist cycles and none of nine hCG cycles resulted in clinical pregnancy (P = 0.1). The results of this study indicate that GnRH agonist is able to simulate a midcycle surge of gonadotropins, leading to follicular maturation and pregnancy. Further work is needed to determine whether there is any clinical advantage of GnRH agonist over hCG administration with regard to pregnancy rates.     

Human follicular fluid insulin concentrations

In mammals, insulin stimulates granulosa cell aromatase activity and steroid production and is a regulating factor of oocyte maturation. To assess the role of insulin in human follicular and oocyte maturation, human follicular fluid was obtained 32-36 h after hCG administration at the time of oocyte recovery for in vitro fertilization. Follicular fluid insulin levels, measured by RIA, ranged from undetectable (less than 2 microU/ml) to 65.4 microU/ml. In women treated with human menopausal gonadotropin (n = 21), clomiphene citrate (n = 4), and human menopausal gonadotropin/clomiphene citrate (n = 14), follicular fluid insulin concentrations were 18.0 +/- 4.3 (+/- SE), 10.2 +/- 4.2, and 12.0 +/- 3.8 microU/ml, respectively (P = NS). Similarly, there was no significant difference in follicular fluid insulin concentrations in follicles with mature (n = 33) or immature (n = 6) oocytes (13.3 +/- 2.7 vs. 24.7 +/- 9.5 microU/ml) or in oocytes which eventually did (n = 35) or did not (n = 4) fertilize (16.4 +/- 3.0 vs. 3.2 +/- 0.8 microU/ml). Follicular fluid insulin levels (n = 30) correlated positively with follicular fluid progesterone levels (P less than 0.05), but not with follicular fluid estradiol or androstenedione levels or the estradiol to androstenedione ratio. The relationship of follicular fluid insulin and progesterone levels suggests that, as in other mammals, follicular fluid insulin may have a physiological role in follicular maturation.     

Opening of glibenclamide-sensitive K+ channels in follicular cells promotes Xenopus oocyte maturation.

The vasorelaxing K+ channel opener P1060 (a pinacidil analog), gonadotropins, and cAMP were shown to activate a glibenclamide-sensitive 86Rb+ efflux from fully grown follicle-enclosed Xenopus oocytes. Glibenclamide-sensitive K+ channels are located in follicular cells. Glibenclamide (i) depressed the gonadotropin- but not the progesterone-induced maturation and (ii) did not significantly modify progesterone production in oocytes exposed to Xenopus gonadotropin. In follicle-enclosed oocytes, the opener P1060 very significantly enhanced the oocyte sensitivity to progesterone. This increased sensitivity to the hormone induced by the K+ channel opener was reversed by glibenclamide. Thus these results suggest that the opening of glibenclamide-sensitive K+ channels in follicular cells by gonadotropins (and other activators of this channel) induces a hyperpolarization in the oocyte that greatly facilitates maturation by increasing the oocyte sensitivity to progesterone.     

Endocrine profiles after triggering of final oocyte maturation with GnRH agonist after cotreatment with the GnRH antagonist ganirelix during ovarian hyperstimulation for in vitro fertilization

In a randomized multicenter study, the efficacies of two different GnRH agonists were compared with that of hCG for triggering final stages of oocyte maturation after ovarian hyperstimulation for in vitro fertilization. Ovarian stimulation was conducted by recombinant FSH (Puregon), and the GnRH antagonist ganirelix (Orgalutran) was coadministered for the prevention of a premature LH rise. Luteal support was provided by daily progestin administration. Frequent blood sampling was performed at midcycle in the first 47 eligible subjects included in the current study, who were randomized for a single dose of 0.2 mg triptorelin (n = 17), 0.5 mg leuprorelin (n = 15), or 10,000 IU hCG (n = 15). Serum concentrations of LH, FSH, E2, and progesterone (P) were assessed at variable intervals. LH peaked at 4 h after both triptorelin and leuprorelin administration, with median LH levels of 130 and 107 IU/liter (P < 0.001), respectively. LH levels returned to baseline after 24 h. Subjects receiving hCG showed peak levels of 240 IU/liter hCG 24 h after administration. A rise in FSH to 19 IU/liter (P < 0.001) was noted in both GnRH agonist groups 8 h after injection. Within 24 h the areas under the curve for LH and FSH were significantly higher (P < 0.001) in both GnRH agonist groups compared with that for hCG. E2 and P levels were similar for all groups up to the day of oocyte retrieval. Luteal phase areas under the curve for P and E2 were significantly elevated (P < 0.001) in the hCG group. The mean (+/-SD) numbers of oocytes retrieved were 9.8 +/- 5.4, 8.7 +/- 4.5, and 8.3 +/- 3.3; the percentages of metaphase II oocytes were 72%, 85%, and 86%; and fertilization rates were 61%, 62%, and 56% in the triptorelin, leuprorelin, and hCG group, respectively (P = NS for all three comparisons). These findings support the effective induction of final oocyte maturation in both GnRH agonist groups. In summary, after treatment with the GnRH antagonist ganirelix for the prevention of premature LH surges, triggering of final stages of oocyte maturation can be induced effectively by a single bolus injection of GnRH agonist, as demonstrated by the induced endogenous LH and FSH surge and the quality and fertilization rate of recovered oocytes. Moreover, corpus luteum formation is induced by GnRH agonists with luteal phase steroid levels closer to the physiological range compared with hCG. This more physiological approach for inducing oocyte maturation may represent a successful and safer alternative for in vitro fertilization patients undergoing ovarian hyperstimulation.     

Mifepristone is an effective oral alternative for the prevention of premature luteinizing hormone surges and/or premature luteinization in women undergoing controlled ovarian hyperstimulation for in vitro fertilization

The present clinical study was conducted to investigate the effectiveness of a daily dose of 40 mg mifepristone in preventing premature LH surges in women undergoing controlled ovarian hyperstimulation (COH) for in vitro fertilization and to study the effect of this antiprogestin cotreatment on endometrial receptivity. This was a prospective, open-label, randomized, exploratory study in 15 healthy volunteer oocyte donors who were randomly allocated to the experimental COH group, including mifepristone (group 1), or the control group, using a long protocol with GnRH agonists (group 2), in a ratio of 2:1, i.e. 10 and five subjects, respectively. In group 1, human chorionic gonadotropin (hCG) was randomly administered (group 1A) or was withheld (group 1B) at the end of stimulation, so that two subgroups of five subjects each were formed, differing in the final oocyte maturation trigger. In all patients receiving mifepristone, 50 mg progesterone were administered im at the time of hCG administration to counteract residual antiprogestogenic activity of mifepristone. Serum estradiol, progesterone (P), LH, and FSH levels were monitored in each patient on d 3 and 6 and every 48 h thereafter. Endometrial biopsies were taken 2 and 7 d after hCG or P administration. Endometrial tissue was processed and evaluated in a blinded fashion for endometrial dating and quantitative PCR of at least four genes known to be up-regulated in receptive endometrium. The total FSH dose and duration of treatment in the two arms of the study were similar. The mean LH levels on d 6 of stimulation and the day of hCG/P treatment in the mifepristone group were 0.8 +/- 0.7 and 0.5 +/- 0.6 mIU/ml, and those in control subjects were 2.4 +/- 3.8 and 2.0 +/- 1.7 mIU/ml, respectively. No LH surges were observed in any subject treated with mifepristone. Serum P levels on the day of hCG/P were below the cut-off level (1.2 ng/ml) in all subjects of the mifepristone group (range, <0.5 to 1.05 ng/ml). The mean numbers of cumulus-oocyte complexes retrieved were 11.6 +/- 6.6 and 19.6 +/- 11.8 in the subgroup treated with mifepristone and hCG and in the control group, respectively. The mean percentages of metaphase II, metaphase I, and germinal vesicle stage oocytes were 86.2, 6.9, and 3.4% in the mifepristone group and 68.4, 6.1, and 11.2% in the control group. In the mifepristone group that did not receive hCG and received P only at the end of stimulation, an endogenous LH surge was not observed nor were oocytes obtained. Histological evaluation of endometrial samples in patients treated with mifepristone and hCG (group 1A) confirmed normal development, whereas in patients treated with mifepristone only (group 1B), there was a complete arrest of the endometrial maturation. The expression patterns of glycodelin, IGF-binding protein-7, glutathione peroxidase-3, and solute carrier family 1 member 1 show a striking absence of up-regulation in patients treated with mifepristone (groups 1A and 1B) compared with controls (group 2). The results of this exploratory study provide evidence that mifepristone is effective for the prevention of premature LH surges and/or premature luteinization in women undergoing COH for in vitro fertilization. However, endometrial receptivity status requires additional evaluation after decreasing RU-486 doses before this strategy can be considered as a new alternative to GnRH agonist/antagonist treatment.     

Induction of multiple follicular development by a single dose of long-acting recombinant follicle-Stimulating hormone (FSH-CTP, corifollitropin alfa) for controlled ovarian stimulation before in vitro fertilization

In a first feasibility study, the efficacy and safety of a single dose of recombinant long-acting FSH (FSH-CTP) were investigated in in vitro fertilization (IVF) patients undergoing controlled ovarian stimulation with a flexible GnRH antagonist protocol. Eligible subjects were randomized to receive a single dose of 120 micro g (n = 25), 180 microg (n = 24), or 240 microg (n = 25) corifollitropin alfa (FSH-CTP) or to start daily fixed doses of 150 IU recombinant FSH (rFSH) (n = 24, reference). Subjects who received a single dose of FSH-CTP continued 1 wk after injection (treatment d 8) with fixed daily doses of 150 IU rFSH (Puregon/Follistim) until the day of triggering final oocyte maturation. The terminal half-life of FSH-CTP was, on average, 65 h and dose independent. Cycle cancellation before human chorionic gonadotropin (hCG) administration occurred in only three subjects treated with FSH-CTP. The median duration of stimulation was 10.0 d in each FSH-CTP group and 9.0 d in the daily rFSH group. The total number of follicles at least 11 mm at stimulation d 8 and at the day of hCG administration tended to increase with dose of FSH-CTP, although a significant dose-response relationship was revealed only for the number of follicles at least 15 mm on the day of hCG (P = 0.03). Serum estradiol levels and inhibin-B levels were not significantly different between the four groups on d 8 and on the day of hCG. In total, 12 subjects (17.6%) in the FSH-CTP groups and two subjects (8.3%) in the rFSH group experienced a premature LH rise (defined as LH >or= 10 IU/liter) before the start of the GnRH antagonist (P value not significant between groups). This relatively high incidence of women demonstrating an early LH rise in the FSH-CTP groups may be related to the higher initial rises of serum estradiol and the use of a flexible GnRH antagonist protocol. The mean number of oocytes recovered per started cycle was higher in FSH-CTP-treated subjects compared with rFSH-treated subjects (significant at P = 0.03 for the 240- microg FSH-CTP group), but no difference could be noted between the number of good quality embryos (range of means, 3.8-4.8 per attempt), and equal numbers of embryos were available for embryo transfer. In summary, FSH-CTP appeared to be a potent inducer of multiple follicular growth; additional research will be needed to select the optimal FSH-CTP dose and treatment time interval.     

Human recombinant luteinizing hormone is as effective as, but safer than, urinary human chorionic gonadotropin in inducing final follicular maturation and ovulation in in vitro fertilization procedures: results of a multicenter double-blind study

In a prospective, comparative, dose-finding study, the minimal effective dose of recombinant human LH (rhLH) required to induce final follicular maturation and early luteinization in patients undergoing in vitro fertilization and embryo transfer was determined. In addition, the efficacy and safety of rhLH were compared with urinary human CG (u-hCG). A total of 259 infertile women, aged 18-39 yr, were enrolled in the study. After pituitary desensitization using a GnRH agonist, rhFSH was administered for ovarian stimulation. Patients then received either rhLH or u-hCG to achieve final follicular maturation. The doses of rhLH administered were 5,000, 15,000, 30,000, or 15,000 + 10,000 IU (second injection administered 3 days after the first injection; 129 patients), and those of u-hCG were consistently 5,000 IU (121 patients). Ovum pick-up was performed 34--38 h after rhLH or u-hCG injection. After fertilization in vitro, up to three embryos were replaced in the uterine cavity. The numbers of oocytes retrieved after u-hCG or rhLH administration were not significantly different between the four different doses of rhLH, when compared with each corresponding u-hCG group, nor when compared with the pool of all u-hCG groups. Similarly, there were no statistically significant differences in: the number of oocytes retrieved per follicle with a diameter of over 10 mm on the day of u-hCG or rhLH administration; the number of patients with at least one oocyte retrieved; oocyte nuclear maturity; oocyte potential for fertilization; the number of embryos; the number of total, biochemical, and clinical pregnancies; and the embryo implantation rate. However, in many of these parameters, the lowest dose of rhLH seemed suboptimal when compared with the higher dose. In terms of safety, rhLH was well tolerated at a dose of up to 30,000 IU. Moderate ovarian hyperstimulation syndrome (OHSS) was reported in 12.4% of patients who received u-hCG and 12.0% of patients who received two injections of rhLH. No moderate or severe OHSS was reported in patients who received a single dose of rhLH up to 30,000 IU. The results show that a single dose of rhLH is effective in inducing final follicular maturation and early luteinization in in vitro fertilization and embryo transfer patients and is comparable with 5,000 IU u-hCG. A single dose of rhLH results in a highly significant reduction in OHSS compared with hCG. The dose of rhLH giving the highest efficacy to safety ratio was between 15,000 and 30,000 IU.     

Predicting oocyte fertilisability in intracytoplasmic sperm injection cycles: a retrospective observational study

Background

Conception assisted by intracytoplasmic sperm injection (ICSI) requires oocyte stripping for morphological evaluation of maturity status. However, this approach prevents further maturation and poorly predicts fertilisability, so more robust assessment strategies are needed. Given that cytokines orchestrate oocyte development, we aimed to assess the association of follicular fluid cytokine profiles with maturation stage and develop predictive machine learning-based methods to identify those with the greatest fertilisation potential.

Tissue-type plasminogen activator in rat oocytes: expression during the periovulatory period, after fertilization, and during follicular atresia

The regulation of tissue-type plasminogen activator (tPA) in rat oocytes during the periovulatory period, in early embryos, and in oocytes during induced follicular atresia was studied using a quantitative chromogenic substrate assay. Oocytes and early embryos were collected from three ovulation models: 1) intact immature female rats treated with PMSG, followed by hCG 48 h later; 2) hypophysectomized immature rats treated with PMSG, followed by a GnRH agonist (GnRHa) 56 h later; and 3) adult cyclic rats on the mornings of proestrus and estrus and up to 5 days after fertilization. In addition, follicular atresia was induced by either withdrawal of diethylstilbestrol (DES) for 2 days or injection of GnRHa for 2 days in hypophysectomized DES-implanted immature rats. Treatment with PMSG alone did not increase oocyte tPA content (5-20 microIU/oocyte) in either immature rat model, but treatment with either hCG or GnRHa induced meiotic maturation and ovulation and increased tPA activity to 80 and 140 microIU/oocyte 24 h after hCG and GnRHa treatment, respectively. Northern blot analysis of total RNA extracted from oocytes of PMSG-treated rats indicated the presence of a specific tPA message at 22S. tPA levels were low in preovulatory oocytes obtained on proestrus morning and increased in ovulated oocytes on estrus morning. After fertilization, tPA levels remained high in the embryos on days 1-4 of pregnancy, but dropped dramatically on day 5. Furthermore, oocytes from atretic follicles of hypophysectomized DES-implanted rats after either DES withdrawal or GnRHa treatment contained elevated levels of tPA, coincident with germinal vesicle breakdown (GVBD). Immunohistochemical staining revealed tPA antigen only in those oocytes that had undergone apparent meiotic maturation, as confirmed by GVBD. Thus, oocytes contain tPA mRNA and synthesize the active protease under a variety of stimuli which result in GVBD. The observed periovulatory increase in oocyte tPA activity, its maintenance until day 5 of pregnancy, and expression of tPA in nonovulatory oocytes of atretic follicles suggest diverse functions for the oocyte and embryo tPA.     

The roles of follicular envelopes in the initiation of Xenopus oocyte maturation

Gonadotropins and progesterone induce in vitro meiotic maturation of the follicleenclosed Xenopus laevis oocyte. The kinetics of maturation are identical for both hormones. The enzymatic removal of the follicular envelopes which suppresses gonadotropin activity does not modify the efficiency of progesterone (1 μM)-induced maturation. It was, however, shown that defolliculation decreases the kinetic of maturation: GVBD₅₀ (the time necessary to obtain 50% of germinal vesicle breakdown or maturation) was 8.08 ± 1.25 hr when follicles are induced to mature in the presence of progesterone and 4.30 ± 0.89 hr in the case of defolliculated oocytes. This result demonstrates that the follicular envelopes play a role in inhibition of steroid-induced maturation. When oocytes are defolliculated in the presence of aminogluthetimide, an inhibitor of steroid synthesis, the kinetic of oocyte maturation is also decreased (GVBD₅₀: 4.98 ± 1.75 hr) indicating that the biosynthesis of steroid at the level of follicular envelopes is not involved in the phenomenon.     

Follicle luteinization in hyperandrogenic follicles of polycystic ovary syndrome patients undergoing gonadotropin therapy for in vitro fertilization

CONTEXT: Polycystic ovary syndrome (PCOS) is a reproductive disorder of ovarian hyperandrogenism and insulin resistance characterized by abnormal luteinization of small follicles. After exposure to GnRH analog/FSH stimulation for in vitro fertilization (IVF), however, it is unclear whether such PCOS follicles remain abnormally luteinized during the resumption of oocyte maturation in vivo. OBJECTIVE: The aim of this study was to determine whether PCOS follicles exposed to GnRH analog/FSH stimulation for IVF show abnormal luteinization. DESIGN: This study was a prospective cohort. SETTING: The setting was an institutional practice. Patients: Eleven PCOS and 30 normoandrogenic ovulatory women were included. INTERVENTION(S): All subjects received GnRH analog/FSH therapy after basal serum hormone determinations. MAIN OUTCOME MEASURE(S): Follicle fluid aspirated at oocyte retrieval from the first follicle of each ovary was assayed for gonadotropins, steroids, insulin, and glucose. LH receptor mRNA expression was determined in granulosa cells of the same follicle. RESULTS: In PCOS patients with basal hyperandrogenemia and hyperinsulinemia, total oocyte number was increased and follicle diameter was decreased, despite normal maximal serum estradiol levels. Within PCOS follicles, progesterone levels were reduced (P < 0.01), despite comparable bioactive LH and insulin levels and granulosa cell LH receptor mRNA expression; estradiol levels were normal, despite diminished FSH availability (P < 0.004). Elevated androstenedione (P < 0.01), testosterone (P < 0.001), and glucose (P < 0.01) levels also occurred. In PCOS follicles containing mature oocytes, however, elevated androgen levels were accompanied by both normal progesterone concentrations and a normal inverse relationship between glucose depletion and lactate accumulation. CONCLUSION: Hyperandrogenic follicles with mature oocytes from PCOS women receiving GnRH analog/recombinant human FSH therapy for IVF show sufficient glucose utilization for normal luteinization.     

Periovulatory follicular fluid hormone levels in spontaneous human cycles

We measured follicular fluid hormone levels in 48 normally cycling infertile women who underwent follicle puncture and oocyte retrieval during diagnostic laparoscopy at time-bracketed intervals after an endogenous LH surge. Follicular fluid LH, FSH, PRL, estrone (E1), estradiol (E2), progesterone (P), androstenedione (A), and testosterone (T) concentrations and P/E2 and A/E2 ratios were determined. Oocytes were classified as germinal vesicle (gv), metaphase I (mI), metaphase II (mII), or degenerating (dg). Follicular fluid (ff) hormone levels then were correlated with the stage of oocyte maturation. There were no differences in ff E1 or E2 levels at any stage of oocyte maturation, except that the mean ff E2 concentration was significantly (P less than 0.05) lower in ff containing dg oocytes [2,474 +/- 1,435 (+/- SE) nmol/L] than in those containing the other oocyte stages. The mean P levels were significantly (P less than 0.0001) higher in ff containing mI (48,781 +/- 10,240 nmol/L) and mII (41,801 +/- 11,098 nmol/L) oocytes than in ff containing gv oocytes (1371 +/- 696 nmol/L). The mean A level was highest (P less than 0.01) in dg-associated ff. Similarly, T was highest (P less than 0.05) in ff containing dg (52 +/- 14 nmol/L) oocytes than in ff containing mI (10.7 +/- 10.1 nmol/L) or mII (10.1 +/- 4 nmol/L) oocytes, and it was also elevated (P less than 0.05) in gv ff (72 +/- 33 nmol/L) compared to mII ff. The above differences also were reflected in the P/E2 ratio, which was significantly higher (P less than 0.05) in mI and mII ff, as well as in the A/E2 ratio, which was higher (P less than 0.05) in ff containing mI and mII oocytes compared to ff containing gv or dg oocytes. These data define the evolving changes in the microenvironment of the follicular fluid of preovulatory follicles of normally cycling women. They also provide reference points for analysis of ff obtained from women during stimulated cycles intended for in vitro fertilization.     

Decline of follicular oocyte maturation inhibitor coincident with maturation and achievement of fertilizability of oocytes recovered at midcycle of gonadotropin-treated women.

To examine whether a decline in follicular oocyte maturation inhibitor (OMI) is associated with attainment of oocyte maturation and fertilizability, OMI was measured in follicular fluid (FF) of 39 follicles of 20 normal women given human menopausal gonadotrophin and human chorionic gonadotrophin to induce follicular growth and maturation. Oocytes were aspirated per laparoscope, the fluid was saved, and the egg was observed, incubated, and inseminated with the husband's sperm. Concepti that developed to the 4- to 8-cell stage were transferred to the uterus and the women were followed for pregnancy. OMI activity in each FF was measured by using cultured cumulus-enclosed porcine oocytes (30-40 oocytes per FF sample). Estrogen, progesterone, oocytes (30-40 oocytes per FF sample). Estrogen, progesterone, and delta 4-androstenedione were measured in FF by radioimmunoassay. The FF of 13 preovulatory follicles yielding oocytes that were mature and fertilizable had significantly less OMI activity (mean +/- SEM) (0.58 +/- 0.10 unit/ml) compared to follicles yielding immature oocytes (2.8 +/- 0.56 units/ml; n = 9), atretic oocytes (5.5 +/- 2.5 units/ml; n = 7), or preovulatory oocytes with fractured zonae (1.9 +/- 0.63 units/ml; n = 7). The estrogen concentration (mean +/- SEM) of preovulatory follicles yielding mature fertilizable eggs or mature eggs with fractured zonae was greater (396 +/- 34 ng/ml; n = 20) compared to follicles yielding immature or atretic eggs (203 +/- 59 ng/ml; n = 9 and 97 +/- 47 ng/ml; n = 7, respectively; P less than 0.05). Progesterone concentration (mean +/- SEM; ng/ml) of FF was generally elevated in all preovulatory follicles (635 +/- 53) compared to immature or atretic follicles (230 +/- 64 and 76 +/- 17, respectively; P less than 0.05). It may be concluded that in normal follicle maturation there is a decline in OMI in the follicle containing an oocyte that becomes mature and fertilizable. There is also an increase in estrogen, progesterone, and follicle size. It is also possible to have an abnormal follicle maturation when there is an increase in size as well as FF, estrogen, and progesterone, but withut a decline in OMI--a situation which can lead to production of a nonfertilizable oocyte.     

Evidence for the presence of keratinocyte growth factor (KGF) in human ovarian follicles.

The presence of keratinocyte growth factor (KGF) in human follicular fluid (FF) was investigated in a total of 145 FFs obtained during oocyte retrieval for in vitro fertilization (IVF) from 29 patients with no apparent endocrine disorders. The concentrations of KGF, estradiol, progesterone, testosterone and human chorionic gonadotropin (hCG) in FF were measured by enzyme-linked immunosorbent assay. FF samples contained relatively higher amounts of KGF (2194+/-87 pg/ml), whereas its concentrations in serum were below assay limit (<31.2 pg/ml). Concentrations of KGF in FF were positively correlated with both progesterone (r=0.311, p<0.0005) and testosterone (r=0.230, p<0.01) concentrations in FF. However, KGF concentrations were not significantly correlated with estradiol and hCG concentrations. KGF in FF was detected as a broad band (26-29 kD) by immunoblotting, the size being reduced by 7kD after N-glycosidase treatment. In an in vitro experiment, KGF suppressed the basal and hCG-stimulated progesterone production by cultured human luteinized granulosa cells. summary, we demonstrated the presence of KGF in human ovarian follicles, suggesting its possible role as a local factor in regulating human ovarian functions.     

Relationship between sex hormone-binding globulin and pregnancy outcome in women undergoing controlled ovarian hyperstimulation for assisted reproduction

The purpose of this study was to determine whether the changes of sex hormone-binding globulin (SHBG) affect the pregnancy outcome in women undergoing controlled ovarian hyperstimulation (COH) for assisted reproduction. Forty-five infertile women who were undergoing pituitary desensitization and COH for in vitro fertilization (IVF) with or without intracytoplasmic sperm injection (ICSI) and 19 women with normal menstrual cycles participated in the study. Fasting blood samples of the follicular and luteal phases, including follicular fluid during oocyte retrieval, were obtained for determination of estradiol (E(2)), progesterone (P(4)), testosterone (T), and SHBG concentrations. The SHBG levels increased progressively during the course of COH, but remained constant throughout normal menstrual cycles. A positive correlation existed between E(2) and SHBG levels in both the follicular and luteal phases. The mean plasma SHBG concentration and E(2)/T ratio were significantly higher, while the level of T and the free androgen index were significantly lower, in the luteal phase of women who conceived than in those who did not conceive following COH. The changes of follicular fluid SHBG level and E(2)/T ratio were similar to those in plasma. We concluded, therefore, that increases in SHBG in the follicular and luteal phases may be a reflection of the functional state of ovarian stimulation, and further that such elevations may influence the pregnancy outcome through the modulation of circulating estrogen and androgen balance during down-regulated COH cycles for IVF/ICSI.     

Involvement of leukotriene B4 in ovulation in the rabbit.

The present study was undertaken to assess the effects of lipoxygenase products on ovulation, oocyte maturation, and steroid production in the perfused rabbit ovary preparation. Ovulatory efficiency was significantly reduced when rabbit ovaries were perfused with human CG (hCG) plus nordihydroguaiaretic acid (NDGA) at 10(-5) or 10(-6) M, as compared to contralateral hCG-treated controls. The addition of NDGA to the perfusate inhibited hCG-induced ovulation in a dose-related manner. The percentage of ovulated ova and follicular oocytes achieving germinal vesicle breakdown did not differ significantly between NDGA-treated ovaries and contralateral controls. Leukotriene B4 (LTB4) production by the perfused rabbit ovaries reached its maximum 6 h after exposure to hCG and then declined. The addition of NDGA at 10(-5) M significantly inhibited hCG-stimulated LTB4 production by rabbit ovaries throughout the entire perfusion periods. The ovulatory efficiency in ovaries treated with hCG alone or with hCG plus NDGA correlated significantly with LTB4 production by perfused rabbit ovaries 6 h after exposure to hCG (alpha = 0.8893, P less than 0.01). Furthermore, the addition of LTB4 at 100 ng/ml to the perfusate reversed the inhibitory effects of NDGA on hCG-induced ovulation. However, exposure to NDGA affected neither progesterone nor estradiol production elicited by hCG administration. These results suggest that NDGA may block hCG-induced ovulation in vitro, probably via the inhibition of LTB4 production by rabbit ovaries.