Daily Injections Of FSH Research Articles

PIH7 - LONG-ACTING RECOMBINANT FSH (CORIFOLLITROPIN ALFA) VERSUS RECOMBINANT FSH AS ASSISTED REPRODUCTION TECHNIQUES IN THE MANAGEMENT OF INFERTILITY: A SYSTEMATIC REVIEW AND META-ANALYSIS

Assisted reproductive technologies (ARTs) are well-established treatments for many types of subfertility. Current treatment regimens prescribe daily injections of FSH (urinary FSH or recombinant FSH (rFSH)). Corifollitropin alfa (CRFa) is a new long-acting FSH which can replace seven daily FSH injections during the first week of controlled ovarian stimulation. This study was aimed to compare the effectiveness of CRFa versus rFSH in terms of pregnancy and safety outcomes in women undergoing ARTs. A systematic review was conducted in major databases including PubMed, Cochrane, Embase, Google scholar, and Web of Science up to June 2018 with limitation to English full-text published articles. Data extraction and assessment of risk of bias was independently done by two review authors. Mantel-Henszel odds ratios (OR) and standardized mean differences (SMD) were calculated for outcomes. The primary outcomes were live birth rate, ovarian hyperstimulation syndrome (OHSS) rate, the number of oocytes retrieved, and the number of embryos transferred. Meta-analysis was performed using RevMan 5.3 software. The study examined nine RCTs including 2407 patients receiving CRFa and 2056 women receiving daily rFSH. Although women receiving CRFa had a significantly higher number of oocyte retrieved (SMD: +0.25 , 95%CI: 0.11-0.39 ), number of metaphase II oocytes (SMD: +0.28 , 95%CI: 0.11-0.44 ), and number of embryos obtained (SMD: +0.27 , 95%CI: 0.13-0.41), in comparison to rFSH; there was a significant differences in the rate of embryos transferred in favor of rFSH (OR: 0.68, 95%CI: 0.55–0.85). However, no significant differences between CRFa and rFSH was found with respect to the majority of clinical effectiveness and safety parameters considered including live birth rate, ongoing pregnancy rate, clinical pregnancy rate, miscarriage rate, and OHSS rate. A single dose of CRFa for the first 7 days of ovarian stimulation is a generally well-tolerated and equally effective treatment compared with rFSH.

Медичні переваги контрольованої стимуляції яєчників із застосуванням антагоністів гонадотропін-рилізинг-гормону та корифолітропіну альфа у клініці ЕКЗ у поганих відповідачів

The objective: study of the effectiveness of coriophyllotropin alpha in controlled ovarian stimulation regimens with gonadotropin-rilising hormone antagonists in poor responders. Materials and methods. The study of the effectiveness of the controlled ovarian stimulation regimen using long acting FSH in the protocol with GnRH antagonists was compared with the daily administration of recombinant FSH by the number of oocytes received, embryo digestion, pregnancy and implantation. Results. It has been shown that ovarian stimulation with the use of coriophyllotropin alfa is as effective as a daily injection of recombinant FSH for the treatment of patients with a poor response to stimulation. In addition, the perception of patients with protocols with corifolithopropin alfa results in better tolerability than traditional protocols due to fewer injections, which reduces the likelihood of early termination of treatment. Conclusion. The presented results of the study prove the effectiveness of using corifolotropin alpha in combination with additional FSH daly doses and gonadotropin-rilising hormone antagonists. The effectiveness of this regimen is comparable with standard daily FSH injections for poor responders patients. The study regimen simplify the design of the stimulation scheme, minimize the number of injections, and shorten the duration of the cycle. Key words: controlled ovarian stimulation, poor responders, coriophyllotropin alpha.

El uso de la corifolitropina alfa en donantes de óvulos obtiene la misma eficiencia reproductiva y efectividad que la FSH recombinante, con una mayor comodidad para la donante

IntroductionConventional ovarian stimulation with daily injections of FSH for oocyte donors, besides the discomfort of the medication, involves a great demand of time. Treatments need to be simplified without losing effectiveness and safety. Corifollitropin alpha (Elonva) enables the first 7injections of FSH to be replaced with one single injection. ObjectiveTo compare the effectiveness and convenience of corifollitropin alpha (Elonva) compared to daily recombinant FSH (rFSH) in the ovarian stimulation of oocyte donors. Materials and methodsAn analysis was performed on 90 cycles of Elonva and 96 cycles of rFSH. The statistical analysis included the Student t-test for means and the chi-squared test for percentages. Effectiveness has been evaluated through reproductive effectiveness defined as the total number of live births in relation to the total number of mature eggs. An analysis was also performed on variables, such as number of mature oocytes, percentage of viable embryos, implantation rate, and clinical pregnancy rate per embryo transfer. Comfort has been evaluated by the number of visits to the clinic for medication administration. ResultsSignificant differences were only found in the number of injections administered to donors (3.20 Elonva vs. 8.55 rFSH, P<.005). Reproductive effectiveness was 5.61 vs. 5.49, with implantation rate 44.44 vs. 44.34, and clinical pregnancy 56.25 vs. 58.73. There no significant differences in any of variables analysed, including the mean cost. No cases of OHSS or adverse drug reactions were observed. ConclusionsThe use of corifollitropin alpha in oocyte donors offers the same reproductive effectiveness and is more convenient for the donor compared to stimulation with daily rFSH.

The role of corifollitropin alfa in controlled ovarian stimulation for IVF in combination with GnRH antagonist

Corifollitropin alfa is a synthetic recombinant follicle-stimulating hormone (rFSH) molecule containing a hybrid beta subunit, which provides a plasma half-life of ∼65 hours while maintaining its pharmocodynamic activity. A single injection of corifollitropin alfa can replace daily FSH injections for the first week of ovarian stimulation for in vitro fertilization. Stimulation can be continued with daily FSH injections if the need arises. To date, more than 2500 anticipated normoresponder women have participated in clinical trials with corifollitropin alfa. It is noteworthy that one-third of women did not require additional gonadotropin injections and reached human chorionic gonadotropin criterion on day 8. The optimal corifollitropin dose has been calculated to be 100 μg for women with a body weight ≤60 kg and 150 μg for women with a body weight >60 kg, respectively. Combination of corifollitropin with daily gonadotropin-releasing hormone antagonist injections starting on stimulation day 5 seems to yield similar or significantly higher numbers of oocytes and good quality embryos, as well as similar ongoing pregnancy rates compared with women stimulated with daily rFSH injections. Stimulation characteristics, embryology, and clinical outcomes seem consistent with repeated corifollitropin-stimulated assisted reproductive technologies cycles. Multiple pregnancy or ovarian hyperstimulation syndrome rates with corifollitropin were not increased over daily FSH regimen. The corifollitropin alfa molecule does not seem to be immunogenic and does not induce neutralizing antibody formation. Drug hypersensitivity and injection-site reactions are not increased. Incidence and nature of adverse events and serious adverse events are similar to daily FSH injections. Current trials do not provide information regarding use of corifollitropin alfa in anticipated hyper- and poor responders to gonadotropin stimulation. Although corifollitropin alfa is unlikely to be teratogenic, at the moment data on congenital malformations is missing.

Repeated ovarian stimulation with corifollitropin alfa in patients in a GnRH antagonist protocol: no concern for immunogenicity

BACKGROUNDOne injection of corifollitropin alfa replaces the first seven daily FSH injections in controlled ovarian stimulation (COS) cycles. Repeated treatment with therapeutic proteins may cause immune responses or hypersensitivity reactions. We assessed the immunogenicity and safety of corifollitropin alfa treatment in up to three COS cycles.METHODSIn this multicentre, phase III uncontrolled trial, patients (>60 kg) started treatment with one injection of 150 µg corifollitropin alfa on cycle Day 2 or 3 of menses and 0.25 mg ganielix on stimulation Day 5 or 6. Primary outcome measures were antibody formation against corifollitropin alfa (using highly sensitive radioimmunoprecipitation assay), hypersensitivity reactions, local tolerance and adverse events (AEs).RESULTSFirst, second and third COS cycles were started by 682, 375 and 198 patients, respectively. No clinically relevant immunogenicity or drug-related hypersensitivity was observed. For 192 patients undergoing their third cycle a post-treatment blood sample was negative in the anti-corifollitropin antibody assay, resulting in an upper limit of the one-sided 95% confidence interval (CI) of 1.5%. Most frequent AEs were procedural pain (17.7%, 95% CI: 14.9–20.8%), headache (9.1%, 95% CI: 7.0–11.5%) and pelvic pain (7.6%, 95% CI: 5.7–9.9%).Cumulative ongoing pregnancy rate after three cycles, including frozen-thawed embryo transfer cycles and spontaneous pregnancies, was 61% (95% CI: 56–65%) after censoring for patients who discontinued.CONCLUSIONSTreatment with corifollitropin alfa can safely and effectively initiate and sustain ovarian stimulation during the first 7 days of COS in normal responder patients undergoing up to three treatment cycles, without concerns of immunogenicity.The trial was registered under ClinicalTrials.gov identifier NCT00696878.

Patient evaluation of the use of follitropin alfa in a prefilled ready-to-use injection pen in assisted reproductive technology: an observational study

BackgroundSelf-administration of recombinant human follicle-stimulating hormone (r-hFSH) can be performed using injection pen devices by women undergoing assisted reproductive technology procedures. The objective of this study was to explore the use of the prefilled follitropin alfa pen in routine assisted reproductive technology procedures in Germany.MethodsThis prospective, observational study was conducted across 43 German IVF centres over a period of 1.75 years. Patients who had used the prefilled follitropin alfa pen in the current or a previous cycle of controlled ovarian stimulation completed a questionnaire to assess their opinions of the device.ResultsA total of 5328 patients were included in the study. Of these, 2888 reported that they had previous experience of daily FSH injections. Significantly more patients reported that less training was required to use the prefilled follitropin alfa pen than a syringe and lyophilized powder (1997/3081 [64.8%]; p < 0.001 'less' versus 'more' training). Significantly more patients rated the prefilled follitropin alfa pen as easier in terms of use (2321/3206, 72.4%; p < 0.001 'much more easy' versus 'less easy') and daily injection (2384/3262, 73.1%; p < 0.001 'much more easy' versus 'less easy') than existing injection methods. Approximately one third of respondents rated the prefilled follitropin alfa pen as easier to use than the follitropin beta pen with reloadable cartridges. The majority (3378/4024, 83.9%) of patients had a general preference for the prefilled follitropin alfa pen over other injection methods.ConclusionsIn this questionnaire-based survey, routine use of the prefilled follitropin alfa pen was well accepted and associated with favourable patient perceptions. Users of the pen found it easier to initially learn how to use, and subsequently use, than other injection methods. In general, the prefilled follitropin alfa pen was the preferred method for self-administration of gonadotrophins. Together with previous findings, the results here indicate a high level of patient satisfaction among users of the prefilled follitropin alfa pen for daily self-administration of r-hFSH.

Advances in recombinant DNA technology: corifollitropin alfa, a hybrid molecule with sustained follicle-stimulating activity and reduced injection frequency

Recombinant DNA technologies have been used to develop longer-acting therapeutic proteins. One approach is to introduce sequences containing additional glycosylation sites. Using this technique, a new chimeric gene has been developed containing the coding sequences of the FSH beta-subunit and the C-terminal peptide of the hCG beta-subunit, which bears four O-linked oligosaccharide binding sites. Co-expression of the alpha-subunit and the chimeric FSH beta-subunit produces a new recombinant molecule, named corifollitropin alfa, with a prolonged elimination half-life and enhanced in vivo bioactivity compared with wild-type FSH. Medline searches by subject and additional searching by hand. Initial studies in pituitary suppressed female volunteers confirmed the extended half-life of the compound. Phase II studies have shown that corifollitropin alfa is able to induce and sustain multi-follicular growth for an entire week in women undergoing ovarian stimulation using GnRH antagonist co-treatment for IVF. Corifollitropin alfa regimens have been developed with dosages of 100 and 150 microg, for patients with body weight </=60 and >60 kg, respectively. Corifollitropin alfa is the first long-acting hybrid molecule with sustained follicle-stimulating activity developed for the induction of multi-follicular growth along with GnRH antagonist co-treatment for IVF. This new treatment option may be simpler and more convenient for patients compared with conventional long protocols of daily FSH injections in combination with GnRH agonist co-treatment. The safety and efficacy of such regimens is currently being evaluated in large comparative phase III clinical trials. The development of corifollitropin alfa is the first step towards a new generation of recombinant gonadotrophins.

Effects of plane of nutrition on in vitro fertilization and early embryonic development in sheep1

Nutrition has been shown to influence several reproductive functions, including hormone production, oocyte competence and fertilization, and early embryonic development. To determine the effects of maternal diet on in vitro fertilization (IVF) and early embryonic development, ewes (n = 18; 47.0 +/- 1.5 kg of initial BW) were divided into control and underfed (60% of control) nutritional planes for 8 wk before oocyte collection. Pelleted diets containing 2.4 Mcal of ME/kg and 13% CP (DM basis) were fed once daily. During the first 4-wk acclimation phase, control and underfed ewes were fed 1,000 and 600 g/d, respectively. From wk 4 to 8, control (adequate) ewes were fed to maintain BW and offered 720 g/d, whereas underfed ewes received 432 g/d (60% restricted). Synchronization of estrus was performed using progestagen sponges for 14 d. Follicular development was induced by twice daily injections of FSH on d 13 (5 units/injection) and 14 (4 units/injection) of the estrous cycle. Oocytes were collected from all visible follicles on d 15 of the estrous cycle. After IVF, the proportion of developing embryos was evaluated throughout an 8-d culture period. Under-nutrition decreased (P < 0.006) the rate of cleavage, number of blastocysts per ewe, and rate of blastocyst formation (from 79 to 64%; from 3.3 to 0.8; and from 31 to 8%, respectively). However, the number of visible follicles, total number of oocytes, number of healthy oocytes, percentage of healthy oocytes, number of cleaved oocytes, and morula formation per ewe were similar for control and underfed ewes. These data indicate that undernutrition of donor ewes, resulting in lower BW and BCS, has a negative effect on oocyte quality, which results in lower rates of cleavage and blastocyst formation.

Prediction of chances for success or complications in gonadotrophin ovulation induction in normogonadotrophic anovulatory infertility

This follow-up study evaluated whether initial screening characteristics predict treatment outcome of gonadotrophin induction of ovulation. One hundred and fifty-four women with normogonadotrophic anovulatory infertility for whom clomiphene citrate induction of ovulation was unsuccessful were included in the present study. Daily FSH injections were initiated on day 3–5 after spontaneous or progestagen-induced withdrawal bleeding. In most patients, a dose finding low-dose step-up regimen was applied during the first treatment cycle in order to identify the individual FSH response dose. In all subsequent cycles, a step-down protocol was applied. Initial serum concentrations of LH, testosterone and androstenedione were significant predictors for the probability of multi-follicular development. FSH treatment resulted in a total of 67 (44%) ongoing pregnancies. Comparing those women who did, versus those who did not, achieve an ongoing pregnancy in a multivariate Cox regression analysis, initial serum insulin-like growth factor-I (IGF-I), testosterone and women's age entered into the final model (AUC = 0.67). The individual treatment outcome following gonadotrophin induction of ovulation may be predicted by initial screening characteristics.

Differential requirement for pulsatile LH during the follicular phase and exposure to the preovulatory LH surge for oocyte fertilization and embryo development in cattle

The requirement for pulsatile LH and the LH surge for the acquisition of oocyte fertilizing potential and embryo developmental competency was examined in Zebu heifers. Follicular growth was superstimulated using the GnRH agonist-LH protocol in which pulsatile LH and the preovulatory LH surge are blocked. In experiment 1, heifers were assigned on Day 7 of the estrous cycle to receive: group 1A (n=5), 1.5mg norgestomet (NOR) implant; group 1B (n=5), GnRH agonist implant. Follicular growth was superstimulated with 2× daily injections of FSH from Day 10 (a.m.) to Day 13 (p.m.), with PGF2α injection on Day 12 (a.m.). Heifers were ovariectomized on Day 15 (a.m.) and oocytes were placed immediately into fertilization, without 24h maturation. Respective cleavage and blastocyst development rates were: group 1A, 0/64 oocytes (0%) and 0/64 (0%); group 1B, 34/70 oocytes (48.6%) and 2/70 (2.9%). In experiment 2, heifers were assigned on Day 7 of the estrous cycle to receive: group 2A (n=10), 1.5mg NOR implant; group 2B (n=10), GnRH agonist implant; group 2C (n=10), GnRH agonist implant. Follicular growth was superstimulated as in experiment 1 above. Heifers in groups 2A and 2B received an injection of 25mg LH on Day 14 (p.m.) and all heifers were ovariectomized on Day 15 (a.m.); oocytes were placed immediately into fertilization without 24h maturation. Cleavage rates were similar for heifers in group 2A (84/175 oocytes, 48.0%), group 2B (61/112 oocytes, 54.5%) and group 2C (69/163, 42.3%). Blastocyst development rates were similar for heifers in group 2A (22/175 oocytes, 12.6%) and group 2B (25/112 oocytes, 22.3%) and lower (P<0.05) for heifers in group 2C (9/163 oocytes, 5.5%). Oocytes obtained from heifers treated with GnRH agonist, without injection of exogenous LH, underwent cleavage indicating that neither pulsatile LH nor the preovulatory LH surge are obligatory for nuclear maturation in cattle oocytes. Exposure to a surge-like increase in plasma LH increased embryo developmental competency indicating that the preovulatory LH surge promotes cytoplasmic maturation. The findings have important implications for controlling the in vivo maturation of oocytes before in vitro procedures including nuclear transfer.

A Comparison of 3-Day and Daily FSH Injections (Days 1–6) in Women Undergoing Ovarian Stimulation

Objectives: Daily injections of FSH is the standard regimen for follicular growth stimulation. FSH injected on alternate days has proven effective, as has an alternate-day, step-down FSH regimen. This study examined the efficacy of further spacing of FSH injections in women undergoing ovarian stimulation prior to IVF-ET. Design: A pilot, open, randomized, parallel group study conducted at a single German center (1998–2000), involving infertile women who failed to conceive after at least 1 year of unprotected coitus, and whose infertility justified IVF-ET. Materials and Methods: Following pituitary downregulation, patients were randomized to receive either 450 IU FSH at 3-day intervals or 150 IU FSH daily for the first 6 days of follicular stimulation. From day 7, dose titration of r-hFSH was based on ovarian response for all patients; treatment was continued until follicular development was considered adequate (one follicle ≥18 mm, two or more follicles ≥16 mm, E2 within an acceptable range). A single dose of 5000 IU urinary-hCG was administered to promote final follicular maturation. Results: 48 patients in the 3-day dose group and 50 in the daily dose group received hCG. Patients in the 3-day dose group had, by the end of the study, received significantly fewer injections than those who had received daily r-hFSH from day 1; 7.7 and 10.6, respectively (p<0.001, ANOVA). A significantly higher mean number of oocytes was retrieved in the daily dose group (11.0 compared with 8.5 in the 3-day dose group; p = 0.028, ANOVA), but there were no significant differences between the groups in mean values for: total cumulative r-hFSH dose, number of follicles ≥11 mm and ≥14 mm, number of oocytes inseminated (7.0 and 8.3 in the 3-day and daily dose groups, respectively) and number of transferred embryos (2.1 in both groups). Analysis of the implantation and pregnancy rates revealed a clear trend favoring the 3-day dose regimen. Implantation rates were 17% and 10% in the 3-day and daily dose groups, respectively (p = 0.264, ANOVA), while biochemical and clinical pregnancy rates were 29.2% and 14% (p = 0.086, Fisher’s exact test) and 25% and 14% (p = 0.206; Fisher’s exact test), respectively. Conclusions: In patients undergoing ovarian stimulation prior to IVF-ET, administration of r-hFSH at 3-day intervals for the first 6 days of follicular stimulation significantly reduces the total number of r-hFSH injections compared with a conventional FSH regimen (7.7 vs. 10.6, respectively, p<0.001). Pregnancy rates, while in favor of the 3-day dose group, did not achieve statistical significance difference. A reduction in injection frequency would be expected to further increase patient acceptability. This study was sponsored by Ares-Serona International SA, Geneva, Switzerland.

Effect of treatment with recombinant bovine somatotropin on responses to superovulatory treatment in swamp buffalo ( Bubalus bubalis)

The objective of this study was to determine the effect of treatment with recombinant bovine somatotropin (rBST) on the response to superovulatory treatment in swamp buffalo. Estrous cycles of 16 buffalo cows were synchronized by intravaginal administration of progesterone and estradiol benzoate, and the cows were then randomly divided into 2 groups. The rBST-treated group received 250 mg of a sustained-release formula of rBST on Day 4 after progesterone implantation, whereas the control group did not receive rBST. Both groups were then given a superovulatory regimen of twice daily injections of FSH for 3.5 d (total dose of 260 mg, im), between Days 9 and 11 after administration of progesterone. The cows were bred naturally 1 d after the last FSH injection, then 6 d after breeding they were slaughtered, and their reproductive tracts were removed. The numbers of corpora lutea (CL) and follicles were recorded, and embryos were flushed out of the uterine horns. There were no significant differences between the rBST-treated and control cows for the mean numbers (± SEM) of CL (6.0 ± 2.2 vs 4.3 ± 1.1), follicles (15.9 ± 4.1 vs 19.8 ± 2.9), or total embryos recovered per collection (4.5 ± 1.6 vs 2.3 ± 1.0). However, there were significant differences between rBST-treated and control cows for the numbers of transferable embryos per collection (3.0 ± 1.0 vs 0.8 ± 0.3; P ≤ 0.05) and the overall proportion of transferable embryos (75 vs 33%; P ≤ 0.01). The results of this study show that pretreatment of swamp buffalo with rBST significantly increases the production of transferable embryos in response to superovulation.

Use of a GnRH agonist to prevent the endogenous LH surge and injection of exogenous LH to induce ovulation in heifers superstimulated with FSH: A new model for superovulation

A new protocol for superovulating cattle which allows for control of the timing of ovulation after superstimulation with FSH was developed. The preovulatory LH surge was blocked with the GnRH agonist deslorelin, and ovulation was induced by injection of LH. In Experiment 1, heifers (3-yr-old) were assigned to a control group (Group 1A, n = 4) or a group with deslorelin implants (Group 1B, n = 5). On Day -7, heifers in Group 1A received a progestagen CIDR-B ®device, while heifers in Group 1B received a CIDR-B ®device + deslorelin implants. Both groups were superstimulated with twice daily injections of FSH (Folltropin ®-V): Day 0, 40 mg (80 mg total dose on Day 0); Day 1, 30 mg; Day 2, 20 mg; Day 3, 10 mg. On Day 2, heifers were given PGF (a.m.) and CIDR-B ® devices were removed (p.m.). Three heifers in Group 1A had a LH surge and ovulated, whereas neither of these events occurred in Group 1B (with deslorelin implants) heifers. In Experiment 2, heifers (3-yr-old) were assigned to 1 of 4 equal groups (n = 6). On Day -7, heifers in Group 2A received a norgestomet implant, while heifers in Groups 2B, 2C and 2D received norgestomet + deslorelin implants. Heifers were superstimulated with FSH starting on Day 0 as in Experiment 1. On Day 2, heifers were given PGF (a.m.) and norgestomet implants were removed (p.m.). Heifers in Groups 2B to 2D were given 25 mg LH (Lutropin ®): Group 2B, Day 4 (a.m.); Group 2C, Day 4 (p.m.); Group 2D, Day 5 (a.m.). Heifers in Group 2A were inseminated at estrus and 12 and 24 h later, while heifers in Groups 2B to 2D were inseminated at the time of respective LH injection and 12 and 24 h later. Injection of LH induced ovulation in heifers in Groups 2B to 2D. Heifers in Group 2C had similar total ova and embryos (15.2 ± 1.4) as heifers in Group 2A (11.0 ± 2.8) but greater (P < 0.05) numbers than heifers in Group 2B (7.0 ± 2.3) and Group 2D (6.3 ± 2.0). The number of transferable embryos was similar for heifers in Group 2A (5.8 ± 1.8) and Group 2C (7.3 ± 2.1) but lower (P < 0.05) for heifers in Group 2B (1.2 ± 0.8) and Group 2D (1.3 ± 1.0). The new GnRH agonist-LH protocol does not require observation of estrus, and induces ovulation in superstimulated heifers that would not have an endogenous LH surge.

Early Follicle Growth in the Juvenile Macaca Monkey Ovary: The Effects of Estrogen Priming and Follicle-Stimulating Hormone1

The mechanism(s) that drives preantral and early antral follicle growth in the primate ovary is poorly understood. We previously reported that estrogen does not stimulate preantral or early antral follicle growth in juvenile primates. The purpose of the present study was to determine whether estrogen priming may play a role in enhancing FSH-stimulated follicle growth. Eight juvenile monkeys received implants on Day 1 of silastic capsules containing estradiol (or vehicle) to elevate circulating estradiol levels. Daily FSH injections were initiated on Day 4 and continued for up to 12 days. The left ovary was removed on Day 8 and served as a control. Ovulation was induced, and a luteal phase followed. On the first day of menses, the estradiol (vehicle) capsule-FSH protocol was repeated. The remaining ovary was removed on Day 8 of the second cycle. The number and size of all follicles in both ovaries were evaluated by light microscopy. Results indicate that estrogen priming in the first cycle did not enhance growth of preantral or antral follicles, but did result in fewer developing follicles > 1.0 mm in diameter, this was accompanied by an increase in early atretic antral follicles of similar size. In the second cycle, an even further reduction in number and size of developing antral follicles > 1.0 mm in diameter was observed. These data suggest that pretreatment with exogenous estrogen has an anti-follicular action on follicle growth in these primates.

Follicular Development, Progesterone and Estradiol-17.BETA. Levels during Spontaneous and FSH-Stimulated Estrous Cycles in Hokkaido Native Pony and Thoroughbred Mares.

Follicular development, incidence of double ovulations, and steroid hormone levels were examined in Hokkaido Native Pony (HNP) and Thoroughbred (TB) mares during control and FSH-stimulated cycles. Daily FSH treatment (HNP 8 mg FSH/day and TB 16 mg FSH/day; i.m.) was initiated on Day 7 of the estrous cycle following PGF2α, administration on Day 6 (ovulation = Day 0). Follicular development and ovulation was monitored by transrectal ultrasonography. Peripheral blood concentrations of progesterone and estradiol-17β were evaluated by EIA. FSH treatment had no effect on the maximum follicular diameter attained during the estrous period and the diameter of the biggest follicle before ovulation. The incidence of a second follicle >10 mm before ovulation was 0/12 (HNP) and 7/9 (TB) during control cycles. During FSH-stimulated cycles, 2/7 (HNP) and 5/6 (TB)mares had a second follicle >10 mm before ovulation. No double ovulations could be observed in HNP mares during 16 control cycles and 12 FSH-stimulated cycles. In TB mares, double ovulations occurred in 2 out of 14 control cycles and 6 out of 11 FSH-stimulated cycles (P<0.05). Progesterone levels after ovulation were not influenced by FSH treat-ment. Mean concentrations of estradiol-17β during estrus were not different in control and FSH-stimulated cycles. However, maximum estradiol-17β levels were higher in control cycles (6.4 pg/ ml vs. 4.1 pg/ml; P<0.05). It is concluded that treatment with daily injections of FSH is effective in inducing double ovulations in Thoroughbred mares.

Synergistic Effects of Follicle-Stimulating Hormone and Testosterone on the Maintenance of Spermiogenesis in Hypophysectomized Rats: Relationship with the Androgen-Binding Protein Status*

The present study examined the relationship between the functional status of Sertoli cells and the maintenance and restoration of spermatogenesis in immature hypophysectomized (HPX) rats given various doses of exogenous testosterone with or without daily injections of FSH for 90 days. Subcutaneous implantation of a 2- to 10-cm testosterone capsule (TC) increased serum testosterone levels of HPX rats 2-10 times above the normal control levels, but did not significantly increase the testicular testosterone level. Daily injections of FSH significantly increased the accumulation of testosterone in testes of TC-implanted HPX rats. Maintenance of early spermiogenesis was observed in all TC-implanted animals. Although elongated spermatids were present, step 18-19 spermatids at the luminal edge of stages VII-VIII epithelium were only observed in rats bearing 10-cm TC implants. Daily injection of FSH resulted in the completion of spermiogenesis in all TC-implanted animals, and the number of step 18-19 spermatids was dependent on the length of TC implants used. These results demonstrate the importance of the synergism of FSH and testosterone in the final steps of spermiogenesis. The androgen-binding protein (ABP) content per testis of the HPX rats was stimulated by TC implants. However, a significant increase in epididymal ABP was only noted in rats bearing 10-cm TC implants. Injection of FSH resulted in a significant increase in the testicular ABP content in rats bearing 2- or 5-cm TC, but not in those with 10-cm TC implants. In addition, the epididymal ABP content was significantly stimulated by FSH in all TC-implanted animals. The ABP status in the testis and its transport toward the epididymis are closely related to the extent of maintenance of spermiogenesis. It is speculated that the production of ABP by Sertoli cells and the biochemical properties of ABP molecules may have some role in the control of the final steps of spermiogenesis.

Direct Inhibitory Effect of Estrogen on Leydig Cell Function of Hypophysectomized Rats

The effects of estrogen upon testicular gonadotropin receptors and Leydig cell responses were studied. Immature hypophysectomized rats were treated for 7 days with 50 μg FSH, with or without diethylstilbestrol (DES). Daily injections of FSH induced a marked increase in testis weight; this weight increase was inhibited by concomitant DES treatment. FSH also induced an increase in testicular LH/hCG receptor content; the increase in [125I]iodo-hCG binding was not affected by daily injections of low doses (0.01 and 0.2 μg) of DES but was prevented by treatment with high doses (5 and 20 μg) of DES. In contrast, no significant change in testicular [125I]iodo-FSH-binding capacity was detected in any treatment group. Functional responses of the Leydig cells of hypophysectomized rats were studied by incubation of decapsulated testes with or without a saturating concentration of hCG. Daily treatment of FSH caused a marked increase in both basal and stimulated levels of testosterone production. In contrast, with or ...

Hormonal Regulation of Spermidine Formation during Spermatogenesis in the Rat*

The activities of ornithine decarboxylase and S-adenosyl-L-methionine decarboxylase have been correlated with spermidine content and morphological criteria of cell differentiation during hormone-dependent spermatogenesis in the rat. The specific activity of ornithine decarboxylase was maximal at 3 days of age at a time when only Sertoli cells were present in the seminiferous tubules, but the specific activity was markedly reduced with the formation of additional cell types. The specific activity of S-adenosyl-L-methionine decarboxylase increased steadily during spermatogenesis, reaching a plateau with spermatozoan maturation. Spermidine concentration generally paralleled the specific activity of ornithine decarboxylase, and evidenced an increase during spermatid maturation. Hypophysectomy prevented these characteristic developmental enzyme changes and reduced testis spermidine content. Stimulation with daily injections of FSH and LH or of testosterone maintained the normal developmental pattern and the sp...

Sorbitol dehydrogenase of rat testis: changes of activity during development, after hypophysectomy and following gonadotrophic hormone administration.

Sorbitol dehydrogenase (SDH) was examined as a possible marker protein of testicular development and following gonadotrophic stimulation of immature or mature hypophysectomized rats. This enzyme which is localized in a 105,000 supernatant fluid was determined to exhibit a Km for sorbitol of 2.5 X 10-3M. Levels of SDH were correlated with the morphological state of maturation of the germinal epithelium of testicular tubules. SA of SDH increased during testicular development from 0.45 nmoles NAD/min/mg protein at 10 days to maximal activity of 3.2 nmoles NAD/min/mg protein at 60 days. Hypophysectomy of 60–day—old animals initiated a marked and progressive decrease in enzymatic activity between 12 and 39 days postoperatively. Loss of SDH activity paralleled the disappearance of advanced germ cells from the tubules. Daily injections of FSH or LH for 14 days (between 24 and 39 days postoperatively) maintained SDH activity at the level present in 24–day hypophysectomized animals. FSH only maintained the state o...