A human-based assisted reproduction protocol for the menstruating spiny mouse, Acomys cahirinus.

The Egyptian or Common spiny mouse (A. cahirinus) is the first rodent species to show human-like menstruation and spontaneous decidualisation. We consider from these, and its other, human-like characteristics that this species will be a more useful and appropriate small animal model for human reproductive studies. Based on this, there is a need to develop specific laboratory-based assisted reproduction protocols including superovulation, in-vitro fertilisation, embryo cryopreservation and transfer to expand and make this model more relevant. Because standard rodent superovulation has not been successful in the spiny mouse, we have selected to test a human protocol. Female spiny mice will receive a subcutaneous GnRH agonist implant and be allowed to recover. Menstrual cycle lengths will then be allowed to stabilize prior to ovarian stimulation. After recovery, females will be injected IP once a day for 4 days with a FSH analogue, to induce follicular growth, and on day 5 will be injected IP with a hCG analogue to trigger ovulation. Females will either be culled 36hrs after trigger to collect oocytes or immediately paired with a stud male and two cell embryos collected 48hrs later. Mature oocytes will be inseminated using fresh spiny mouse spermatozoa and all in-vitro grown and in-vivo collected two cell embryos will be cryopreserved using methods developed in a close spiny mouse relative, the Mongolian gerbil. For embryo transfer, vitrified embryos will be rapidly warmed and non-surgically transferred to surrogate mice. Surrogates will be monitored until pregnancy is apparent (roughly 30 days) and then left undisturbed until birth, 38-40 days after transfer. By successfully developing robust assisted reproduction protocols in A. cahirinus we will be able to use this rodent as a more effective model for human reproduction.

Sperm DNA Methylation Epimutation Biomarkers for Male Infertility and FSH Therapeutic Responsiveness.

Male factor infertility is increasing and recognized as playing a key role in reproductive health and disease. The current primary diagnostic approach is to assess sperm quality associated with reduced sperm number and motility, which has been historically of limited success in separating fertile from infertile males. The current study was designed to develop a molecular analysis to identify male idiopathic infertility using genome wide alterations in sperm DNA methylation. A signature of differential DNA methylation regions (DMRs) was identified to be associated with male idiopathic infertility patients. A promising therapeutic treatment of male infertility is the use of follicle stimulating hormone (FSH) analogs which improved sperm numbers and motility in a sub-population of infertility patients. The current study also identified genome-wide DMRs that were associated with the patients that were responsive to FSH therapy versus those that were non-responsive. This novel use of epigenetic biomarkers to identify responsive versus non-responsive patient populations is anticipated to dramatically improve clinical trials and facilitate therapeutic treatment of male infertility patients. The use of epigenetic biomarkers for disease and therapeutic responsiveness is anticipated to be applicable for other medical conditions.

High cGMP and low PDE3A activity are associated with oocyte meiotic incompetence.

Resumption of meiosis in mammalian oocytes, defined as oocyte maturation, is stimulated by luteinizing hormone (LH). Fully grown oocytes can also mature spontaneously, upon their release from the ovarian follicle. However, growing oocytes fail to resume meiosis in vitro and the mechanism underlying their meiotic incompetence is unknown. It is commonly accepted that a drop in intraoocyte cyclic guanosine monophosphate (cGMP) resulting in the elevated activity of the oocyte-specific PDE3A leads to a decrease in cAMP content, essential for reinitiation of meiosis. We explored the regulation of these cyclic nucleotides and their degrading PDE3A in growing oocytes. Our research addressed the LH-induced rather than spontaneous oocyte maturation. We examined 16-21 as compared to 25-day-old, PMSG-primed rats, treated with the LH analog, hCG. The effect of LH was also examined ex vivo, in isolated ovarian follicles. We found that hCG failed to induce oocyte maturation and ovulation in the younger animals and that ovulation-associated genes were not upregulated in response to this gonadotropin. Furthemore, the drop of intraoocyte cGMP and cAMP observed in fully grown oocytes upon exposure of the ovary to LH, was not detected in growing oocytes. Interestingly, whereas the global expression of PDE3A in growing and fully grown oocytes is similar, a significantly lower activity of this enzyme was determined in growing oocytes. Our findings show that meiotic incompetence is associated with a relatively high oocyte cGMP concentration and a low activity of PDE3A, which in follicle-enclosed oocytes may represent the failure of the somatic follicle cells to respond to LH.

Evaluation of gonadotropin-replacement therapy in male patients with hypogonadotropic hypogonadism.

Hypogonadotropic hypogonadism (HH) is a rare disease in which medical treatment has a high success rate to achieve fertility. This study aimed to analyze the efficacy of hormone replacement therapy and determine predictive factors for successful spermatogenesis and spontaneous pregnancy in patients with idiopathic HH. A total of 112 patients with low testosterone (T), luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and normal prolactin levels were diagnosed with HH and administered LH and FSH analogs as hormone replacement therapy. During treatment, 96 (85.7%) patients had sperm present in ejaculate samples. Among these patients, 72 were married and wanted a child. Of these 72 patients, 48 (66.7%) of couples had pregnancies from natural conception. After initiation of treatment, the mean time for the appearance of sperm in semen was 9.48 months. There were no significant differences between baseline FSH, T, and LH levels; however, older age, larger testicular size, and low rate of undescended testes were favorable factors for successful spermatogenesis. Larger testicular size and older age were also the main predictive factors for natural conception. We found that patients with undescended testes had a younger age, smaller testes, and lower T levels compared with patients exhibiting descended testes. The rate of sperm found in the ejaculate was not significantly decreased in patients with undescended compared with descended testis (73.7% vs 87.6%, P = 0.261). The medical approach for males with HH and azoospermia provides a successful treatment modality in regard to successful spermatogenesis and achievement of pregnancy.

Pharmacogenetics of G-protein-coupled receptors variants: FSH receptor and infertility treatment.

Infertility treatment may represent a paradigmatic example of precision medicine. Follicle-stimulating hormone (FSH) has been proposed as a valuable therapeutic option both in males and in females, even if a standardized approach is far to be established. To date, several genetic mutations as well as polymorphisms have been demonstrated to significantly affect the pathophysiology of FSH-FSH receptor (FSHR) interaction, although the underlying molecular mechanisms remain unclear. This review aims to highlight possible aspects of FSH therapy that could benefit from a pharmacogenetic approach, providing an up-to-date overview of the variability of the response to FSH treatment in both sexes. Specific sections are dedicated to the clinical use of FSH in infertility and how FSHR polymorphisms may affect the therapeutic endpoints.

Preparation, characterization and application of long-acting FSH analogs for assisted reproduction.

Assisted reproduction technologies are widely used in humans and domestic animals and often include follicle stimulating hormone (FSH) in the protocol. One limitation with most of the available FSH preparations is the relative short half-life in the circulation that dictates multiple daily injections for the desired follicle development and superovulation. The development of bioactive long-acting structurally modified FSH analogs is desirable for human and veterinary use. In addition, optimal preparations and/or formulations are expected to improve the regimen and efficiency of the treatment. This review briefly describes the approaches that have been explored to extend the half-life of FSH in the circulation. These include strategies to increase the mass and/or charge of FSH and to prevent the dissociation of the hormone to inactive subunits components. Most of these strategies, except one that led to a registered drug (Elonva) indicated for controlled ovarian stimulation protocols in humans, are still in experimental stage.

Oral follicle-stimulating hormone agonist tested in healthy young women of reproductive age failed to demonstrate effect on follicular development but affected thyroid function.

OBJECTIVE: To assess the safety, pharmacokinetics, and pharmacodynamics of MK-8389. DESIGN: Double-blind, placebo-controlled, parallel-group, ascending dose study. SETTING: Two clinical research organizations. PATIENT(S): Healthy young women. INTERVENTION(S): Once-daily oral doses of MK-8389 or placebo for 14 days. MAIN OUTCOME MEASURE(S): Safety, including thyroid function tests (TFTs), pharmacokinetics, and follicular development (follicle size and number and serum E2 and inhibin B levels). RESULT(S): Treatment with MK-8389 was generally safe and well tolerated. An effect on TFTs was observed, which was transient and did not lead to clinical signs or symptoms but prevented dose escalation above 40 mg. MK-8389 was rapidly absorbed, slowly eliminated, and showed a large peak-to-trough ratio. No clinically meaningful effect was seen on follicle size and numbers, which was consistent with the low E2 levels. At doses >20 mg, inhibin B levels were increased, suggesting early follicular development at higher doses. CONCLUSION(S): Oral administration of MK-8389 demonstrated acceptable systemic exposure and was generally well tolerated. This study failed to demonstrate a clinically meaningful effect of MK-8389 on follicular development, whereas MK-8389 unexpectedly affected thyroid function. This study did not explore doses above 40 mg given the changes observed in TFTs, which may relate to high MK-8389 peak concentrations. CLINICAL TRIAL REGISTRATION NUMBER: EudraCT Number 2010-022396-57.

Effect of time and dose of recombinant follicle stimulating hormone agonist on the superovulatory response of sheep.

The objective of this study was to determine the superovulatory potential of a single-chain analog of human FSH (Fcα) when administered to ewes either 3 days before, or coincident with, simulated luteolysis (pessary removal [PR]). A total of 40 animals were randomly assigned to receive Fcα at doses of 0.62, 1.25, or 2.5 IU/kg of body weight (bwt) 3 days before PR or 0.31, 0.62, 1.25, or 2.5 IU/kg of bwt at PR. Control ewes received protein without FSH activity. Blood samples were collected during the periovulatory period and ovarian tissue was collected 11 days after PR. Ovulation rate did not differ from the control group in ewes receiving the smallest doses of Fcα (0.31 and 0.62 IU/kg). However, a significant superovulatory response was noted in sheep receiving Fcα at doses of 1.25 and 2.5 IU/kg and this response was comparable in animals receiving the largest dose levels of Fcα at, or 3 days before, PR. The interval between PR and the LH surge was significantly extended and the LH surges were less synchronous in animals receiving Fcα at PR when compared with animals receiving the potent FSH agonist 3 days before PR. Taken together, these data indicate that the human single-chain gonadotropin with FSH activity promotes superovulation in ewe lambs in the breeding season. A single injection of the recombinant gonadotropin 3 days before luteolysis synchronizes the LH surge. The use of the single-chain analog of FSH in assisted reproduction for domestic animals is likely to be of practical significance as an alternative to conventional gonadotropins in superovulation protocols in livestock species.

Rerouting of a follicle-stimulating hormone analog to the regulated secretory pathway.

LH and FSH are produced by the same gonadotrope cells of the anterior pituitary but differ in their mode of secretion. This coordinated secretion of LH and FSH is essential for normal follicular development and ovulation in females and for spermatogenesis in males. The structural signals encoded in the LH and FSH subunits that govern the intracellular sorting of LH through the regulated secretory pathway and FSH through the constitutive pathway are largely unknown. Our laboratory recently identified the seven amino acid carboxy tail of LH beta as a sorting signal for LH in GH(3) cells. Here we compared the morphological features of GH(3) cells expressing an FSH analog containing the heptapeptide (FL7AA) with wild-type FSH using confocal microscopy. These experiments were performed to develop a rerouting model for examining structure-function links between secretion pathways of FSH/LH and their biological action. Both FSH- and LH-expressing cells exhibit a fluorescence pattern of randomly dispersed cytoplasmic puncta. FL7AA expressing cells have more intracellular accumulation compared with wild-type FSH and display a unique halo pattern of fluorescence near the plasma membrane. Such a pattern was not observed in cells expressing FSH or LH. Our results demonstrate that this FSH analog containing the carboxy heptapeptide of LH beta is rerouted to the regulated secretory pathway in GH(3) cells. This rerouted gonadotropin provides a unique model to study the trafficking, regulation, and function of LH and FSH.

Coactivation of estrogen receptor beta by gonadotropin-induced cofactor GIOT-4.

Estrogen exerts its diverse effects through two subtypes of estrogen receptors (ER), ERalpha and ERbeta. Each subtype has its own distinct function and expression pattern in its target tissues. Little, however, is known about the transcriptional regulatory mechanism of ERbeta in the major ERbeta-expressing tissues. Using biochemical methods, we identified and described a novel ERbeta coactivator. This protein, designated GIOT-4, was biochemically purified from 293F cells. It coactivated ERbeta in ovarian granulosa cells. GIOT-4 expression was induced by stimulation with follicle-stimulating hormone (FSH). GIOT-4 recruited an SWI/SNF-type complex in a ligand-independent manner to ERbeta as an ER subtype-specific physical bridging factor and induced subsequent histone modifications in the ERbeta target gene promoters in a human ovarian granulosa cell line (KGN). Indeed, two ERbeta-specific target genes were upregulated by FSH at a specific stage of a normal ovulatory cycle in intact mice. These findings imply the presence of a novel regulatory convergence between the gonadotropin signaling cascade and ERbeta-mediated transcription in the ovary.

Efficacy of native and hyperglycosylated follicle-stimulating hormone analogs for promoting fertility in female mice.

OBJECTIVE: To compare the efficacy of recombinant human FSH (rhFSH) with rhFSH with four additional O-linked carbohydrates (rhFSH-CTP), rhFSH with four additional N-linked carbohydrates (rhFSH-N4), and the current gold standard for rodent ovarian stimulation, pregnant mare serum gonadotropin (PMSG), on fertility parameters in mice. DESIGN: Animal study. SETTING: Academic research center. ANIMAL(S): Adult C57Bl/6J female mice. INTERVENTION(S): Ovarian stimulation with 5 IU of rhFSH, rhFSH-CTP, rhFSH-N4, or PMSG. Forty-six hours later, 5 IU of hCG was injected to promote ovulation and females were mated overnight. MAIN OUTCOME MEASURE(S): Eggs retrieved after ovulation, in vitro embryo development, delivery rate, and litter size. RESULT(S): The hyperglycosylated FSH analogs, rhFSH-CTP and rhFSH-N4, enhanced ovulation and embryo maturation significantly better than rhFSH. RhFSH-N4 produced more eggs (28.5 +/- 1.9 per mouse) and embryos (17.8 +/- 1.6) compared with rhFSH-CTP (18.3 +/- 1.2 and 9.0 +/- 1.0, respectively). Treatment with rhFSH, rhFSH-N4, and PMSG produced statistically equivalent delivery rates and litter sizes. The delivery rate was surprisingly lower with rhFSH-CTP (14%) compared with PMSG (33%). CONCLUSION(S): Compared with rhFSH, treatment with hyperglycosylated rhFSH-CTP and rhFSH-N4 led to superior rates of ovulated eggs and subsequent in vitro embryo development. RhFSH-N4 was equivalent to PMSG, while all of the fertility parameters studied were lower with rhFSH-CTP than with PMSG therapy.

Occurrence of postmenopausal-like acidic follicle-stimulating hormone (FSH) isoforms precedes the rise of FSH before menopause.

OBJECTIVE: To assess the glycoform distribution patterns of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) during the menstrual cycle at different ages and FSH levels, after menopause, and with premature ovarian failure (POF). DESIGN: Controlled clinical study. SETTING: Healthy volunteers in an academic research environment. PATIENT(S): Women aged 20 to 25 years with normal early follicular (EF) serum FSH (<10 IU/L), women aged 40 to 45 years with normal or increased EF serum FSH, postmenopausal women, and women with POF. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): FSH and LH glycoform distributions as assessed by chromatofocusing. RESULT(S): In both postmenopausal and in women with POF, more acidic FSH glycoforms were found compared with young cyclic premenopausal women. In women aged 40 to 45 years with normal FSH levels, these acidic glycoform profiles already showed a statistically significant difference from the younger women. This difference was to attributable to the early follicular and luteal cycle phases. Overall, during aging and after ovarian failure, FSH becomes more acidic, a difference that is already statistically significantly detectable in premenopausal, older women before FSH rises. This is not seen for LH glycoforms. CONCLUSION(S): The occurrence of postmenopausal-like acidic FSH isoforms precedes the rise of FSH before menopause.

[Expression of goat follicle-stimulating hormone analogous gene in Pichia pastoris].

In order to obtain the long-acting FSH preparation, the single strand long-acting analogous gene FSHbeta-CTP-alpha was successfully constructed by the C-terminal peptide(CTP) of carboxyl-terminal region of human chorionic gonadotropin with the goat FSHalpha-subunit and beta-subunit genes, then it was inserted into pPIC9K vector. The recombinant plasmid pPIC9K FSHbeta-CTP-alpha was transformed into Pichia pastoris GS115 by electroporation. The multi-copy inserts His+Mut+ were gained by the screening of phenotype and hyper-resistance to G418. After methanol induction, the supernatant was analysised by SDS-Polyacrylamide Gen Electrophoresis and Western blot. The results show that the transformants of FSHbeta-CTP-alpha could express the objective protein successfully and the molecular weight is about 29 kD. The concentration of supernatant was detected by Radio-immunoassay and the average expression of multi-inserts is 91.849 mIU/mL and the low-inserts is 37.419 mIU/mL. The expression of multi-inserts is higher than the low-inserts significantly. This research lay the foundation for studying the structure of FSH and the production of long-acting FSH preparation.

Among patients treated with FSH and GnRH analogues for in vitro fertilization, is the addition of recombinant LH associated with the probability of live birth? A systematic review and meta-analysis.

The aim of this systematic review and meta-analysis was to assess whether the addition of recombinant luteinizing hormone (LH) increases live birth rate, among patients treated with follicle stimulating hormone (FSH) and gonadotrophin-releasing hormone (GnRH) analogues for in vitro fertilization (IVF). Eligible studies were randomized controlled trials (RCTs) answering the research question that contained sufficient information to allow ascertainment of whether randomization was true and whether equality was present between the groups compared, regarding baseline demographic characteristics, gonadotrophin stimulation protocol, number of embryos transferred and luteal phase support administered. A literature search identified seven RCTs (701 patients) that provided the information of interest, among which five reported agonist and two antagonist cycles. The reported outcome measure, clinical pregnancy, was converted to live birth using published data in one study. No significant difference in the probability of live birth was present with or without rLH addition to FSH (odds ratio [OR]: 0.92, 95% confidence interval (CI): 0.65-1.31; P = 0.65). This finding remained stable in subgroup analyses that ordered the studies by dose of rLH added, the type of analogue used to inhibit premature LH surge, the time rLH was added during the follicular phase, the age of patients analysed, the presence of allocation concealment and by the way the information on live birth was retrieved. In conclusion, the available evidence does not support the hypothesis that the addition of recombinant LH increases the live birth rate in patients treated with FSH and GnRH analogues for IVF.

Follicle-stimulating hormone isoforms are not useful as pretreatment predictors of outcome in in vitro fertilization: a pilot study.

The objective of this study was to determine the predictive value of FSH isoforms for the outcome of IVF treatment. Although this pilot study comprises only a small number of patients, we conclude that because no statistical differences could be found in the isoform-composition between poor and good responders, it is not likely that FSH isoforms predict treatment outcome after IVF.

Long-acting follicle-stimulating hormone analogs containing N-linked glycosylation exhibited increased bioactivity compared with o-linked analogs in female rats.

The effects of altering the number and type of additional carbohydrate moieties on the pharmacokinetic and pharmacodynamic properties of FSH were examined in this report. A series of single-chain follitropins, containing variable numbers of additional N- (or O-) linked carbohydrates, were designed and expressed in Chinese hamster ovary cells. Proper folding, efficient receptor binding, and signal transduction were confirmed by in vitro assays. Pharmacokinetic and pharmacodynamic parameters were evaluated in immature female Sprague Dawley rats. Increasing the number of glycosylation sites with either N- (or O-) linked moieties extended the elimination half-life as much as 2-fold compared with recombinant human FSH (rhFSH). However, there was a maximum elimination half-life such that further glycosylation provided no additional lengthening of the half-life. Conversely, biopotency, as assessed by inhibin A levels 74 h post injection, and follicle production were significantly higher for the N-linked analogs. Rats stimulated with the longest acting analogs (either N- or O-linked) showed significantly higher ovarian weights than rats receiving a single injection of rhFSH. The analog containing four additional N-linked sites (rhFSH-N4) had the greatest number of large, preovulatory follicles. Although the half-life of rhFSH-N4 displayed no further enhancement beyond the other longest acting analogs, this analog exhibited significantly increased biopotency in rats. This work provides the basis for the generation of a series of reagents potentially useful for therapeutic applications.

Structural biology of human follitropin and its receptor.

In this review, the current understanding of structure-activity relationships of human follitropin and of the extracellular domain of its receptor is described. Comprehensive mutagenesis of human follitropin combined with the three-dimensional structure of human follitropin has ushered in a new era of understanding of how this complex hormone binds to and activates its receptor. Comparison of human choriogonadotropin and follitropin structures has proved invaluable in understanding how these human glycoprotein hormones have conserved primary sequence that enables high affinity binding while diverging in amino acids that provide specificity. Moreover, by comparison of the structures of deglycosylated and glycosylated human choriogonadotropin and glycosylated human follitropin, there appears to be no influence of oligosaccharides upon backbone conformation of human glycoprotein hormones. Extensive structure-activity relationships of human follitropin receptor have been studied, and new insights gained here as well. These studies indicate that follitropin binds to the central module of the extracellular domain of the follitropin receptor. Biophysical analyses of purified follitropin receptor extracellular domain further revealed conformational changes affected by hormone binding and by the solvent environment. Further, secondary structure analysis of the purified extracellular domain of follitropin receptor favors the leucine-rich repeat motif model of the glycoprotein hormone receptors. Together, the studies indicate that there are only a few residues that contribute to the overall energy of binding. Formation of a weak collisional complex between follitropin and its receptor likely involves complementation of compatible surfaces and steric hindrance by oligosaccharides, followed by conformational change and formation of active site residue salt bridges. In this regard and in light of these new data, current models of the glycoprotein hormone receptors may need to be re-evaluated.

Cysteine residues in a synthetic peptide corresponding to human follicle-stimulating hormone beta-subunit receptor-binding domain 81-95 [hFSH-beta-(81-95)] modulate the in vivo effects of hFSH-beta-(81-95) on the mouse estrous cycle.

We have previously reported that synthetic peptide amides corresponding to subdomains of the human FSH 3-subunit, hFSH-beta-(33--53) and hFSH-beta-(81--95), interact with the external domain of the FSH receptor in two in vitro model systems. Consistent with these in vitro observations, we found that intraperitoneal (i.p.) administration of each of these peptides prolonged vaginal estrus in normally cycling mice in vivo. Both hFSH-beta-(33--53) and hFSH-beta-(81--95) contain cysteine (Cys) residues with free sulfhydryl groups of potential significance in receptor interactions. To assess the possible involvement of these groups in the in vivo effects of hFSH-beta-(33--53) and hFSH-beta-(81--95), synthetic peptide analogs were prepared in which all Cys residues were replaced with serine (Ser). In the present study, we demonstrate that the in vivo effect of hFSH-beta-(33--53) on the mouse estrous cycle, extension of vaginal estrus, was not changed by substitution of Cys-51 with Ser. In contrast, mice receiving the Ser-substituted analog of hFSH-beta-(81--95) had normal estrus stages, but were arrested in diestrus. hFSH-beta-(33--53)-(81--95), a linear peptide encompassing both domains, also prolonged vaginal estrus. The Ser-substituted analog of this peptide, however, prolonged vaginal estrus in some of the mice tested and induced cycle arrest at diestrus in others. hFSH-beta-(90--95), the active subdomain at the C-terminus of hFSH-beta-(81--95), extended vaginal estrus, but diestrus stages were of normal duration. Its Ser-substituted analog, however, prolonged the estrus stage of the majority of mice treated, but induced diestrus arrest in some. The differing responses to these peptides are presumably due to interactions of the synthetic peptides with different regions of the FSH receptor. This further suggests that one consequence of ligand interaction with multiple receptor binding domains may be variable effects on ovarian function, and that Cys to Ser analogs may have value in the design of a novel class of synthetic peptides capable of fertility regulation and control.

Superovulation in cattle: effect of FSH type and method of administration on follicular growth, ovulatory response and endocrine patterns.

Although different FSH preparations and injection regimens are used to superovulate cattle, the optimum treatment regimen and blood concentrations of FSH to induce effective superovulatory responses are currently not known. The current objective was to evaluate the pattern of follicular growth, oestradiol-17 beta(E2) concentrations and yield of embryos in heifers following superovulation with two different pFSH preparations reportedly differing in LH content. In experiment 1, 90 synchronised heifers were superovulated at mid-cycle using a 2 x 2 factorial design comparing Folltropin (Vetrepharm; low LH) with Pluset (Serovet; FSH:LH ratio 1:1) administered either as a single or multiple (8 for Folltropin, MF and 10 for Pluset, MP) injections. Animals were inseminated during oestrus which was induced with prostaglandin F2 alpha analogue and embryos were recovered 7 days later. Overall, Pluset treatments compared with Folltropin resulted in more ovulations and unfertilized or degenerate embryos (P < 0.05). Multiple injections resulted in more (P < 0.05) freezable (MF = 55 +/- 1.2; MP = 3.8 +/- 1.0) and transferable embryos (MF = 2.68 +/- 0.9; MP = 2.71 +/- 0.9) than single injections (SF = 2.2 +/- 0.5 and 1.0 +/- 0.3 respectively; SP = 2.6 +/- 0.8 and 1.3 +/- 0.4 respectively); there was also a higher (P < 0.05) percentage embryo recovery rate. In two subsequent experiments, animals (n = 17) were superovulated with either single or multiple injections of Folltropin or Pluset as described and blood samples were collected and analysed for E2 concentrations. Ovarian scanning was carried out until 72 h after the first FSH injection, to count medium (5-9 mm) and large (> or = 10 mm) follicles. Heifers treated with SP had higher E2 concentrations in comparison with heifers treated with SF at 18, 36-48 and 84-96 h after the FSH injection. There were no differences in E2 concentrations in heifers treated with MF or MP treatments. Heifers treated with SP had greater numbers of follicles compared to SF treated heifers (21.0 +/- 3.1 vs 13.9 +/- 2.2; P = 0.089) on the third day after FSH injection. There were no differences between the numbers of medium and large follicles in heifers treated with MF or MP at any time throughout the experimental period. These data indicate that a single injection of Folltropin or Pluset can result in multiple ovulations and that the E2 profiles are different following single injections of either Folltropin or Pluset.

Regulation of insulin-like growth factor I biosynthesis in porcine granulosa cells.

In the present studies we examined the regulation of insulin-like growth factor I (IGF-I) expression in porcine granulosa cells in vitro. Using Northern analysis and ribonuclease protection assays with exon-specific probes, we identified the IGF-I messenger RNA (mRNA) transcripts present in these cells under basal and hormone-stimulated conditions. We also assessed changes in secreted IGF-I using Western blots and correlated the change in protein secretion after hormone treatment with changes in mRNA levels. By analogy to the human IGF-I gene and its transcription, two major transcripts of approximately 1 and 7.5 kilobases, seen in freshly isolated granulosa cells and follicle wall and in single passaged granulosa (MDGp1) cells, most likely correspond to IGF-IA. Minor transcripts of 3-4 kilobases, which appeared after FSH or forskolin treatments or in control cells after long exposure of the autoradiographs, were attributed to incompletely processed RNA precursors. Ribonuclease protection assay analysis using probes to detect alternative use of exon 5 or exon 6 indicated that most, if not all, of the transcripts contained only exon 6 sequence (IGF-IA). Both class 1 and class 2 transcripts were identified using exon 1- and exon 2-specific probes, respectively. GH increased steady state levels of IGF-I mRNA 3-fold, FSH increased it approximately 10-fold, and forskolin maximally increased it 12- to 15-fold. Estradiol had no effect alone or in combination with the other treatments. All treatments that increased IGF-I mRNA coordinately increased both class 1 and class 2 transcripts, with the increase in class 1 greater than that in class 2. Multiple forms of IGF-I protein were seen under basal conditions and after hormone treatment. These were identified based on mRNA analysis and biochemical methods as both glycosylated and nonglycosylated IGF-IA prohormone, incompletely processed forms of prohormone, and the mature peptide. Changes in the levels of total protein were similar to the changes in mRNA (GH, 3-fold; FSH and forskolin, 10- to 20-fold). All forms of the protein changed coordinately, suggesting that these hormones had no major effect on the intracellular processing mechanism. IGF-binding protein-3 was able to bind to all IGF-I forms. These data conclusively demonstrate FSH and GH induction of ovarian IGF-I. The porcine granulosa cell culture system used in these studies should be an excellent system for studying the hormonal regulation of IGF-I expression.