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Publication
Journal: Experimental Physiology
January/6/2004
Abstract
To our knowledge, the relationship between all four endogenous female sex hormones and resting cardiac autonomic function has not been studied. The aim of the current study was to examine the association between the normal endogenous levels of oestrogen (17beta-oestradiol), progesterone, luteinising hormone and follicle-stimulating hormone and heart rate variability (HRV) during the menstrual cycle in young eumenorrheic women. Ten healthy, young, female subjects volunteered for this study. HRV and endogenous hormone levels were recorded at three phases of the menstrual cycle: menses (day 3.8 +/- 0.5), ovulation (day 15.8 +/- 0.7) and luteal (day 22.1 +/- 0.4) to ensure HRV recordings at times of low (menses) and high (ovulation and luteal) hormonal influence. Heart rate recordings were obtained from supine resting subjects and analysed on a Holter analysis system. Total power (TP, 0-1.0 Hz), low frequency (LF, 0.041-0.15 Hz), high frequency (HF, 0.15-0.80 Hz) and LF/HF components of HRV were examined. Despite a significantly greater HR at ovulation and normal cyclic variations in all endogenous sex hormone levels, no measure of HRV was significantly different between menstrual cycle phases. Significant correlations between oestrogen levels and absolute measures of HRV at ovulation were identified. The results of the current study demonstrated that the normal cyclic variations in endogenous sex hormone levels during the menstrual cycle were not significantly associated with changes in cardiac autonomic control as measured by HRV. Significant correlation between peak oestrogen levels and HRV measures at ovulation provided further support for the reported cardioprotective effects of oestrogen in healthy females.
Publication
Journal: Human Reproduction Update
October/5/1999
Abstract
Many hormones that are central to normal reproductive functioning mediate their physiological effects by activating a receptor which belongs to the large family of G-protein-coupled receptors (GPCR). Members of this family of receptor proteins are usually glycosylated on extracellular domains. In recent years the role of this glycosylation in cell surface expression/protein folding, ligand recognition and receptor-effector coupling has been investigated. This review summarises current knowledge of the role of glycosylation in the functioning of the receptors for gonadotrophin-releasing hormone (GnRH), luteinizing hormone/human chorionic gonadotrophin (LH/HCG), follicle stimulating hormone (FSH), oxytocin (OT) and vasopressin (AVP).
Publication
Journal: Molecular and Cellular Biology
May/15/2002
Abstract
Many growth factors and hormones modulate the reproductive status in mammals. Among these, insulin and insulin-like growth factor I (IGF-I) regulate the development of gonadal tissues. SH2-B has been shown to interact with insulin and IGF-I receptors, although the role of SH2-B in these signals has not been clarified. To investigate the role of SH2-B, we generated mice with a targeted disruption of the SH2-B gene. Both male and female SH2-B(-/-) mice showed slight retardation in growth and impaired fertility. Female knockout mice possess small, anovulatory ovaries with reduced numbers of follicles and male SH2-B(-/-) mice have small testes with a reduced number of sperm. SH2-B(-/-) cumulus cells do not respond to either follicle-stimulating hormone or IGF-I. These data suggest that SH2-B plays a critical role in the IGF-I-mediated reproductive pathway in mice.
Publication
Journal: Human Reproduction Update
November/12/2007
Abstract
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.
Publication
Journal: Endocrinology
March/28/1995
Abstract
Activin is a protein originally isolated from follicular fluid as a factor stimulating FSH release from the pituitary. The present experiments support the hypothesis that activins may also regulate follicle development by autocrine/paracrine mechanisms. Granulosa-oocyte complexes were isolated by collagenase/dispase dispersion of ovaries from 14- or 21-day-old rats and cultured in serum-free medium. Within 24 h, the cells had spread to form a monolayer. Hormones and growth factors were added at this time. Cell number and thymidine incorporation were measured after an additional 72 h. In the presence of insulin and transferrin, activin-A increased both granulosa cell number and thymidine incorporation more than 2-fold. This effect could be inhibited by follistatin, an activin-binding protein. In addition, activin-A, in the presence of FSH, induced reorganization of follicular structures from monolayer culture of cells from 14-day-old rats and caused cells from primary follicles to develop into large follicle-like structures. These structures contained oocytes, a cumulus layer, an antrum, and a multilayered follicular wall with a diameter of more than 1 mm. Electron microscopy revealed that the cells in the follicle-like structure were connected by gap junctions. Oocytes showed a mature morphology and had closely associated cumulus layers. Dissociation of the follicular wall in these follicle-like structures was induced by the addition of LH, resembling the induction of ovulation in vivo. The findings are important for understanding follicular development and atresia.
Publication
Journal: Molecular Endocrinology
April/24/1990
Abstract
Primary pituitary cell cultures derived from adult male rats were used to explore the direct effects of purified porcine inhibin and follistatin, and recombinant human activin A on FSH beta, as well as LH beta and alpha-subunit mRNA levels. Subunit mRNAs were determined by blot hybridization using alpha, LH beta, and FSH beta cDNA and genomic fragments. Treatment with inhibin for 72 h significantly suppressed alpha and FSH beta mRNA levels with parallel changes in FSH secretion. No change in LH beta mRNA levels was observed. A decrease in FSH beta mRNA to undetectable levels was seen 4 h after inhibin administration. Recombinant human Activin A caused dose-dependent and parallel increases in FSH beta mRNA levels and FSH secretion. This increase was evident at 4 h after activin administration and maintained at longer times. alpha and LH beta mRNA levels remained unchanged. Follistatin addition to cultures for 72 h significantly reduced FSH beta mRNA levels. In a time-course experiment, a reduction in FSH beta mRNA to undetectable levels was observed 24 h after follistatin administration. There were no changes in alpha or LH beta mRNA levels. These data demonstrate that the actions of these gonadal peptides on FSH secretion may be accounted for, at least in part at the level of biosynthesis, by reductions in FSH beta mRNA levels directly at the level of the anterior pituitary gland.
Publication
Journal: Biology of Reproduction
September/20/2005
Abstract
In the present study, we cloned and characterized zebrafish FSH receptor (Fshr) and LH receptor (Lhr). Both fshr and lhr were abundantly expressed in the zebrafish gonads; however, they could also be detected in the kidney and liver, respectively. When overexpressed in mammalian cell lines together with a cAMP-responsive reporter gene, zebrafish Fshr responded to goldfish pituitary extract but not hCG, whereas Lhr could be activated by both. It was further demonstrated that Fshr was specific to bFSH, while Lhr could be stimulated by both bovine FSH and LH. Low level of fshr expression could be detected in the immature ovary, but the level steadily increased during vitellogenesis of the first cohort of developing follicles. In contrast, the expression of lhr could barely be detected in the immature ovary, but it became detectable at the beginning of vitellogenesis and steadily increased afterward with the peak level reached at the full-grown stage. At the follicle level, the expression of fshr was very weak in the follicles of primary growth stage but significantly increased with the follicles entering vitellogenesis. However, after reaching the maximal level in the midvitellogenic follicles, the level of fshr expression dropped slightly but significantly at the full-grown stage. In comparison, the expression of lhr obviously lagged behind that of fshr. Its expression became detectable only when the follicles started to accumulate yolk granules, but the level rose steadily afterward and reached the peak at the full-grown stage before oocyte maturation. These results suggest differential roles for Fshr and Lhr in zebrafish ovarian follicle development.
Publication
Journal: Journal of Clinical Investigation
December/18/1985
Abstract
Functional and morphologic heterogeneity of human multinodular goiters was investigated in 300 samples from "cold" and "hot" regions of 20 goiters transplanted onto nude mice. Transplants were labeled with [3H]thymidine and radioiodine, while the host's thyroid-stimulating hormone (TSH) secretion was either stimulated or suppressed. Proliferation and function of follicular cells were assessed in whole follicles reconstructed from autoradiographs of serial sections. Hot transplants had a higher autonomous iodine uptake than those of cold tissue in TSH-suppressed hosts. Functional autonomy widely varied among the follicles, but even more so among individual cells. Hot grafts differed from cold ones only by a comparatively larger fraction of autonomous cells. Intercellular differences of iodinating activity were not abolished by TSH. Grafts faithfully reproduced the individual growth pattern of the original tissue. Between 0.5% and 7% of all follicular cells replicated despite suppression of TSH. Up to 70% of these cells were clustered, forming scattered foci of autonomously growing tissue. Other cells only started replicating after long-term TSH stimulation. Thus, goiters contained subsets of cells with high and others with low growth response. Progenies of replicating cells remained clustered, sometimes budding outwards to form new follicles. Autonomy of growth and autonomy of function are independent traits of epithelial cells. Epithelial cells have their individual growth pattern, replication rate, and functional capacity. These traits are passed on from a mother cell to its progeny during follicle neogenesis. To this main mechanism accounting for the morphologic and functional heterogeneity of human goiters, inheritable modifications of gene expression must probably be added.
Publication
Journal: Human Reproduction
March/18/1996
Abstract
Both follicle stimulating hormone (FSH) and luteinizing hormone (LH) are proposed requirements for follicular growth and steroidogenesis; however, the role of LH in primate folliculogenesis is unclear. Follicular stimulation by recombinant human FSH (n = 5) with and without recombinant LH (1:1; n = 6) following 90 days of gonadotrophin-releasing hormone (GnRH) antagonist (Antide) treatment in macaques was evaluated. Human chorionic gonadotrophin (HCG) was administered when six follicles>> or = 4 mm were observed. Oocytes were aspirated 27 h later and inseminated in vitro. Chronic Antide reduced serum oestradiol and bioactive LH to concentrations observed in hypophysectomized rhesus monkeys. Multiple follicular growth required a longer interval following recombinant FSH (12 +/- 1 days) than recombinant FSH+recombinant LH (9 +/- 0.2 days), but the total number of follicles/animal did not differ between groups. The day prior to HCG, oestradiol concentrations were 4-fold less following recombinant FSH compared to recombinant FSH+recombinant LH. With recombinant FSH, more oocytes completed meiosis to metaphase II (51%) and fertilized (89 +/- 5%) relative to recombinant FSH+recombinant LH (12 and 52 +/- 11% respectively). Follicular growth and maturation in LH-deficient macaques occurred with FSH alone. Thus, LH is not required for folliculogenesis in primates. Higher fertilization rates following follicular stimulation with FSH alone suggest that the presence of LH with FSH (1:1) during the pre-ovulatory interval impairs gametogenic events in the periovulatory period.
Publication
Journal: Journal of Neuroscience Research
December/12/2002
Abstract
In individuals with Alzheimer's disease (AD), there is a two-fold elevation in the serum concentrations of the gonadotropins, luteinizing hormone (LH), and follicle stimulating hormone compared to age-matched controls. Whether this plays a role in disease pathogenesis is unclear. Nonetheless, gonadotropins are known to cross the blood brain barrier and the highest density of gonadotropin receptors in the brain are found within the hippocampus. We report for the first time the localization of LH in the cytoplasm of pyramidal neurons. In addition, we find a significant increase in LH in the cytoplasm of pyramidal neurons and neurofibrillary tangles of AD brain compared to age-matched control brain. Whereas the functional consequences of increased neuronal LH are unknown, it is notable that LH is primarily localized to those neurons that are known to be vulnerable to Alzheimer's disease-related neurodegeneration. Elevated serum and cortical neuron levels of LH, coupled with the decline in sex steroid production, could play important roles in the pathogenesis of AD.
Publication
Journal: Neuroendocrinology
February/6/1996
Abstract
The present studies tested the hypothesis that either short or ultrashort loop negative feedback regulation of gonadotropin-releasing hormone (GnRH) secretion occurs in the ewe. As part of ongoing studies investigating the regulation of follicle-stimulating-hormone secretion, we obtained the unexpected result that a GnRH antagonist (Nal-Glu) may stimulate GnRH secretion. In that experiment, hypophyseal portal blood was collected from five short-term ovariectomized ewes at 5-min intervals for 6 h before and 6 h after intravenous injection of Nal-Glu (10 micrograms/kg body weight). An increase in GnRH pulse frequency in association with the blockade of luteinizing hormone (LH) release was evident in 3 of the 5 animals. To determine if an effect of Nal-Glu on episodic GnRH secretion would be more evident in an animal model in which low-frequency pulses of GnRH prevail, the study was repeated in six ewes in the midluteal phase of the estrous cycle and six ovariectomized ewes bearing estradiol and progesterone implants to suppress GnRH release (artificial luteal model). In luteal-phase ewes, administration of Nal-Glu was followed by an increase in GnRH pulse frequency, pulse size and the secretion of GnRH between pulses, and by a blockade of LH release. In ovariectomized ewes treated with estradiol and progesterone, Nal-Glu administration also stimulated GnRH and inhibited LH secretion. Our finding that the GnRH antagonist stimulated GnRH secretion is consistent with the hypothesis that endogenous GnRH may influence its own release via either a short or ultrashort loop feedback mechanism.
Publication
Journal: Journal of applied physiology: respiratory, environmental and exercise physiology
April/25/1978
Abstract
The effects of exercise on estradiol, progesterone, follicle-stimulating hormones (FSH), and luteinizing hormone (LH) were studied in nine healthy females. Subjects were studied during light, heavy, and exhaustive exercise in the midfollicular and midluteal portions of their menstrual cycles. Resting hormone levels followed the expected pattern. Increases in estradiol and progesterone occurred at all intensities of exercise in the luteal phase but only in estradiol at exhaustion in the follicular phase. LH was unchanged with exercise in either phase and FSH increased in the follicular phase but not in the luteal phase. We conclude that exercise is a physiological stimulus to elevations in plasma estradiol, progesterone, and FSH, but not LH. The elevations are more marked in the luteal phase for the steroids and in the follicular phase for FSH. Increases in estradiol and progesterone are related to the intensity of exercise and appear to be independent of pituitary control.
Publication
Journal: Medical and pediatric oncology
July/24/1996
Abstract
Gonadal function was assessed in 101 postpubertal subjects after chemotherapy for childhood Hodgkin's disease. All had received ChlVPP (chlorambucil, vinblastine, procarbazine, and prednisolone) chemotherapy alone, with no radiotherapy below the diaphragm. Gonadotropin levels were available in 46 (79.3%) male and 32 (74.4%) female subjects. The mean age at diagnosis in the male cohort was 12.2 years (range 8.2-15.3) and in the females 13.0 years (9.0-15.2). The males and the females were studied at a median of 6 years (range 2.5-11.1) and 4.3 years (range 1.9-11.5) from diagnosis, respectively. Forty-one (89.1%) male subjects had elevated follicle-stimulating hormone (FSH) levels, confirming severe germinal epithelial damage. Germinal epithelial damage was seen in subjects up to 10 years out of therapy. Subtle Leydig cell dysfunction was identified in 24.4% with raised luteinzing hormone (LH) levels. All subjects, however, progressed spontaneously through puberty. Seventeen (53%) women had raised gonadotropin levels, with variable estradiol levels. Of these, 10 subjects presented with symptomatic ovarian failure and 6 received hormone replacement therapy (HRT). Nine women had 11 successful pregnancies, two of whom had previously had symptoms of ovarian failure with one requiring HRT. A much higher prevalence of ovarian failure has been observed, than has previously been considered in the prepubertal and pubertal female following combination chemotherapy. These conclusions have important implications for future counseling, management, and research in this population.
Publication
Journal: Human Reproduction
January/12/2000
Abstract
The objective of this study was to determine whether epidermal growth factor (EGF) promotes nuclear and cytoplasmic maturation of mouse oocytes grown in vivo or in vitro. In-vivo-grown oocytes were isolated at the germinal vesicle (GV) stage from gonadotrophin-primed (PR) or -unprimed (UPR) 22-day-old mice before in-vitro maturation (IVM). In-vitro-grown (IVG) oocytes were isolated from preantral follicles of 12-day-old mice and grown in vitro without gonadotrophins for 10 days before maturation (IVG/IVM oocytes). IVM and IVG/IVM oocytes were matured in medium supplemented with either EGF (10 ng/ml), follicle stimulating hormone (FSH) (100 ng/ml), EGF plus FSH, or with neither ligand (control). When oocyte-cumulus cell complexes were isolated from PR and UPR mice, IVM with EGF (10 ng/ml), alone or in combination with FSH (100 ng/ml), increased (P < 0.05) the incidence of nuclear maturation to metaphase II. Cytoplasmic maturation of oocytes from PR females, manifested as increased frequency of cleavage to the 2-cell stage and development to the blastocyst stage, was also enhanced with EGF (P < 0.05). Moreover, EGF increased the number of cells per blastocyst, but only in the absence of FSH (P < 0.01). In contrast, EGF, FSH, or EGF plus FSH did not affect the percentage of oocytes from UPR mice completing preimplantation development, but did increase the number of cells per blastocyst. These ligands also increased the proportion of IVG oocytes reaching metaphase II (53-57%) compared with controls (25%; P < 0.05). EGF alone or in combination with FSH increased (P < 0.05) the frequency of blastocyst formation (23% and 28%, respectively) compared with controls (13%). EGF treatment of maturing IVG oocytes produced blastocysts with more cells than other IVG groups (P < 0.05). It is concluded that gonadotrophins in vivo increase the sensitivity or responsiveness of cumulus cell-enclosed oocytes to EGF, thereby promoting both nuclear and cytoplasmic maturation. However, oocyte-granulosa cell complexes grown in vitro become responsive to EGF without gonadotrophin treatment. Thus, nuclear and cytoplasmic maturation of IVG oocytes is promoted by EGF treatment during meiotic maturation.
Publication
Journal: Bailliere's clinical obstetrics and gynaecology
April/26/1998
Abstract
Androgens are products of progestogen metabolism, intermediates in oestrogen biosynthesis and local regulators of ovarian function. Current understanding of intraovarian androgen formation, metabolism and action is reviewed, highlighting the contribution of androgens to the paracrine regulation of follicular maturation and atresia. Any factor that alters intracellular cAMP levels is a potential modulator of granulosa cell differentiation, and hence follicular development. Androgen appears to modulate gonadotrophin action on granulosa cells through amplification of cAMP-mediated post-receptor signalling. Here it is argued that during intermediate stages of follicular development, locally produced androgen acts via granulosa cell androgen receptors (AR) to promote follicle-stimulating hormone (FSH)-induced granulosa cell differentiation through amplifying cAMP-mediated post-receptor signalling. During late pre-ovulatory follicular development, higher concentrations of cAMP caused by stimulation with luteinizing hormone (LH) suppress granulosa cell proliferation and down-regulate some of the genes induced by FSH at earlier stages of pre-ovulatory development, including aromatase activity. Other granulosa cell functions, including progesterone synthesis, are enhanced by the high concentrations of cAMP induced by LH. There is experimental evidence from studies of rat and non-human primate (common marmoset) ovaries that AR levels in granulosa cells decline during pre-ovulatory follicular maturation. Since androgens augment FSH-induced cAMP formation and action, loss of AR could be a means of avoiding inappropriately high cAMP levels and hence avoiding premature activation of 'high-tone' cAMP-response genes that lead to atresia. Negative regulation of the granulosa cell AR could be part of the intra-ovarian mechanism that determines which follicle(s) becomes dominant and secretes oestrogen in the normal menstrual cycle.
Publication
Journal: Endocrinology
June/28/2012
Abstract
Single GATA-6 (G6(gcko)), GATA-4 (G4(gcko)), and double GATA-4/6 (G4/6(gcko)) granulosa cell-specific knockout mice were generated to further investigate the role of GATA transcription factors in ovarian function in vivo. No reproductive defects were found in G6(gcko) animals. G4(gcko) animals were subfertile as indicated by the reduced number of pups per litter and the release of significantly fewer oocytes at ovulation. In marked contrast, G4/6(gcko) females fail to ovulate and are infertile. Furthermore, G4/6(gcko) females had irregular estrous cycles, which correlate with the abnormal ovarian histology found in unstimulated adult G4/6(gcko) females showing lack of follicular development and increased follicular atresia. Moreover, treatment with exogenous gonadotropins did not rescue folliculogenesis or ovulation in double-knockout G4/6(gcko) mice. In addition, ovary weight and estradiol levels were significantly reduced in G4(gcko) and G4/6(gcko) animals when compared with control and G6(gcko) mice. Aromatase, P450scc, and LH receptor expression was significantly lower in G4(gcko) and G4/6(gcko) mice when compared with control animals. Most prominently, FSH receptor (FSHR) protein was undetectable in granulosa cells of G4(gcko) and G4/6(gcko). Accordingly, gel shift and reporter assays revealed that GATA-4 binds and stimulates the activity of the FSHR promoter. These results demonstrate that GATA-4 and GATA-6 are needed for normal ovarian function. Our data are consistent with a role for GATA-4 in the regulation of the FSHR gene and provide a possible molecular mechanism to explain the fertility defects observed in animals with deficient GATA expression in the ovary.
Publication
Journal: Fertility and Sterility
May/18/2009
Abstract
OBJECTIVE
To assess whether the number of triple CGG expansion of the FMR1 (fragile X) gene, known to correlate at premutation (55-200 repeats) and full mutation (>200 repeats) ranges with risk toward premature ovarian failure (POF), also correlates with milder forms of premature ovarian senescence.
METHODS
Retrospective, controlled cohort study.
METHODS
Academically affiliated, private fertility center.
METHODS
Forty consecutive, new infertility patients, of which 11 presented with a primary diagnosis of repeated pregnancy loss (controls), 23 with prematurely elevated, age-specific baseline follicle stimulating hormone (FSH) levels (i.e., premature ovarian aging, POA) and 6 with POF.
METHODS
Determination of number of triple CGG repeats on both alleles of FMR1 gene and of FSH and anti-Müllerian hormone (AMH) levels as a reflection of ovarian reserve.
METHODS
Statistical correlation of higher (allele-2) triple repeat counts with patients' clinical diagnoses and with FSH and AMH levels.
RESULTS
Mean triple CGG counts increased in parallel to increasing severity of premature ovarian senescence. Repeat expansion numbers at all levels correlated statistically to FSH. An AMH level of <1.0 ng/mL statistically correlated to >32 triple repeats.
CONCLUSIONS
Over 30 triple CGG repeats denote increased risk (and severity) toward premature ovarian senescence in parallel to increasing expansions. Numbers, considered well within the normal range, therefore already denote risk, suggesting that CGG repeats may represent a new test to predict ovarian function and assess female infertility.
Publication
Journal: American Journal of Obstetrics and Gynecology
December/15/1982
Abstract
A group of 23 healthy postmenopausal women received one or more 2-week courses of daily administration of the following estrogen preparations: piperazine estrone sulfate (Ogen), 0.3, 0.625, 1.25, 2.5, and 5.0 mg; micronized estradiol (Estrace), 1, 2, and 10 mg; conjugated estrogens (Premarin), 0.3, 0.625, 1.25, and 2.5 mg; ethinyl estradiol (Estinyl), 10 and 20 micrograms; and diethylstilbestrol, 0.1 and 0.5 mg. Each dosage of each formulation was ingested by three women. In those women who received more than one dosage, each course was separated by a drug-free interval of at least 4 weeks. Pretreatment and posttreatment levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), corticosteroid-binding globulin-binding capacity, sex hormone-binding globulin-binding capacity, angiotensinogen, estrone, and estradiol were determined. The relative potency of these five estrogen formulations was determined by parallel line analysis for each of these responses, except LH. On a weight basis, piperazine estrone sulfate and micronized estradiol were equipotent for all responses. Conjugated estrogens suppressed FSH in a fashion equipotent to that of the other nonsynthetic estrogens; however, for all three hepatic parameters, the response was exaggerated twofold to threefold. The synthetic estrogens, diethylstilbestrol and ethinyl estradiol, were relatively more potent on a weight basis for every response and produced the most marked response (fourfold to eighteenfold in excess of their FSH suppression) for the hepatic parameters.
Publication
Journal: Endocrinology
July/18/2001
Abstract
FSH is a heterodimeric glycoprotein hormone that is produced in the gonadotroph cells of the anterior pituitary. It acts on Sertoli cells of the testis and granulosa cells of the ovary. We previously demonstrated that FSHbeta knockout female mice are infertile due to a block in folliculogenesis preceding antral stage development. To investigate aberrations of ovarian gene regulation in the absence of FSH, we analyzed the expression of several important marker genes using Northern blot and in situ hybridization techniques. Key findings are as follows: 1) Follicles of FSHbeta knockout mice develop a well organized thecal layer, which is positive for P450 17alpha-hydroxylase and LH receptor messenger RNAs (mRNAs). This indicates that theca recruitment is completed autonomously with respect to FSH. 2) Granulosa cells in FSH-deficient mice demonstrate an increase in FSH receptor mRNA, and decreases in P450 aromatase, serum/glucocorticoid-induced kinase, and inhibin/activin subunit mRNAs. These data support studies that implicate FSH signaling cascades in the expression of these genes. 3) In contrast to the thecal layer, granulosa cell populations in FSHbeta knockout mice do not accumulate LH receptor mRNA. This suggests that although the granulosa cells have a block in proliferation at the antral follicle stage in the absence of FSH, they do not initiate programs of terminal differentiation as seen in luteinizing cells of wild-type ovaries. 4) Ovaries of FSH-deficient mice demonstrate a modest decrease in cyclin D2 mRNA, without up-regulation of cell cycle inhibitor mRNAs associated with luteinization (i.e. p15, p27, and p21). Although components of the FSH null phenotype may be caused by partial cyclin D2 loss of function, these findings indicate that the mechanisms of granulosa cell cycle arrest in FSHbeta knockout mice are distinct from those of cycle withdrawal at luteinization. Underscoring the usefulness of the FSH-deficient mouse model, this study clarifies aspects of gonadotropin-dependent folliculogenesis, thecal layer development, cycle control in granulosa cells, and luteinization.
Publication
Journal: Toxicology and Applied Pharmacology
November/17/1994
Abstract
Di-(2-ethylhexyl) phthalate (DEHP) exposure suppressed preovulatory granulosa cell estradiol production in adult cycling rats. The active metabolite of DEHP, mono-(2-ethylhexyl) phthalate (MEHP), suppressed follicle-stimulating hormone (FSH)-stimulated cAMP and progesterone production in cultured rat granulosa cells. To examine how DEHP altered granulosa cell estradiol production, the effects of MEHP were studied in cultures of rat granulosa cells. Granulosa cells were obtained from DES-implanted 25-day-old female Fisher 344 rats and exposed in culture to various concentrations of MEHP (0 to 400 microM) in DMSO. Granulosa cells were stimulated with FSH, 8-bromo cyclic adenosine monophosphate (8br-cAMP), a stable cAMP analog, and various concentrations of testosterone. Estradiol production was measured by standard radioimmunoassays and normalized to cell protein. MEHP suppressed estradiol in a concentration-dependent manner whether granulosa cells were stimulated by FSH or 8-br cAMP. Therefore, MEHP suppressed estradiol independent of its suppression of the FSH-cAMP pathway and, thus, suppressed aromatase conversion of testosterone to estradiol. MEHP (100 microns) decreased the maximum velocity of aromatase in cells supplied with increasing concentrations of testosterone. However, MEHP did not alter the velocity or affinity of microsomal aromatase isolated from adult virgin Sprague-Dawley rat ovaries. Therefore, MEHP altered the absolute amount or availability of aromatase in granulosa cells. Decreased aromatase in granulosa cells would explain decreased estradiol concentrations from DEHP exposure in vivo.
Publication
Journal: Fertility and Sterility
August/26/2009
Abstract
OBJECTIVE
To compare the efficacy and safety of recombinant human FSH (r-hFSH) and hCG treatment for male hypogonadotropic hypogonadism (HH) in different populations and to identify characteristics predictive of spermatogenesis.
METHODS
A combined analysis of data from four clinical trials.
METHODS
Phase III, open-label, noncomparative studies with similar designs conducted in Australia, Europe, Japan, and the United States.
METHODS
One hundred men with complete idiopathic or acquired HH.
METHODS
Pretreatment with hCG for 3-6 months, followed by combination therapy with hCG and r-hFSH (150 IU three times weekly) for up to 18 months. Doses of r-hFSH were adjusted according to spermatozoa count until the maximum dose was reached.
METHODS
The primary efficacy endpoint was a spermatozoa concentration of>>or=1.5 x 10(6)/mL.
RESULTS
A total of 81 men remained azoospermic but achieved normal serum T concentrations after hCG pretreatment. Of these, 68 (84.0%) achieved spermatogenesis and 56 (69.1%) achieved spermatozoa concentrations>>or=1.5 x 10(6)/mL. Large baseline mean testicular volume, low body mass index, and advanced sexual maturity were predictors of good response to therapy. Similar treatment responses were observed across different study populations.
CONCLUSIONS
R-hFSH (combined with hCG) is effective for the restoration of fertility in the majority of men with HH.
Publication
Journal: Breast Cancer Research
July/26/2004
Abstract
BACKGROUND
Isoflavones are hypothesized to protect against breast cancer, but it is not clear whether they act as oestrogens or anti-oestrogens in breast tissue. Our aim was to determine the effects of taking a red clover-derived isoflavone supplement daily for 1 year on mammographic breast density. Effects on oestradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), lymphocyte tyrosine kinase activity and menopausal symptoms were also assessed.
METHODS
A total of 205 women (age range 49-65 years) with Wolfe P2 or DY mammographic breast patterns were randomly assigned to receive either a red clover-derived isoflavone tablet (26 mg biochanin A, 16 mg formononetin, 1 mg genistein and 0.5 mg daidzein) or placebo. Change in mammographic breast density, serum oestradiol, FSH, LH, menopausal symptoms and lymphocyte tyrosine kinase activity from baseline to 12 months were assessed.
RESULTS
A total of 177 women completed the trial. Mammographic breast density decreased in both groups but the difference between the treatment and placebo was not statistically significant. There was a significant interaction between treatment group and oestrogen receptor (ESR1) PvuII polymorphism for the change in estimated percentage breast density (mean +/- standard deviation): TT isoflavone 1.4 +/- 12.3% and TT placebo -9.6 +/- 14.2%; CT isoflavone -5.2 +/- 12.0% and CT placebo -2.8 +/- 10.3%; and CC isoflavone -3.4 +/- 9.7% and CC placebo -1.1 +/- 9.5%. There were no statistically significant treatment effects on oestradiol, FSH, or LH (assessed only in postmenopausal women), or on lymphocyte tyrosine kinase activity. Baseline levels of menopausal symptoms were low, and there were no statistically significant treatment effects on frequency of hot flushes or other menopausal symptoms.
CONCLUSIONS
In contrast to studies showing that conventional hormone replacement therapies increase mammographic breast density, the isoflavone supplement did not increase mammographic breast density in this population of women. Furthermore, there were no effects on oestradiol, gonadotrophins, lymphocyte tyrosine kinase activity, or menopausal symptoms.
Publication
Journal: Journal of Biological Chemistry
September/10/1989
Abstract
In most mammalian ovaries, the cumulus cell-oocyte complex (COC) expands at the time of ovulation by depositing an extensive extracellular matrix between the cumulus cells. This phenomenon can be reproduced in vitro by culturing COCs with follicle-stimulating hormone (FSH) and serum. Biosynthesis of hyaluronic acid (HA) and proteoglycans by mouse COCs in vitro was studied using [3H]glucosamine and [35S]sulfate as metabolic precursors. Radiolabeled complex carbohydrates were analyzed by ion exchange chromatography, specific enzyme digestion followed by high performance liquid chromatography, and gel filtration. The specific activities of [3H]hexosamines in the labeled molecules were determined by measuring the incorporation of 3H and 35S into chondroitin 4-sulfate disaccharides. When COCs were stimulated with FSH, HA biosynthesis increased 20-30-fold between 3-12 h later when expansion occurs, reaching a maximum rate of approximately 780 pmol (as glucosamine)/COC/h compared with the unstimulated rate of approximately 26 pmol/COC/h. The final concentration of HA in the expanded COC was calculated to be approximately 250 micrograms/ml. The effects of dibutyryl cyclic AMP (Bt2cAMP) on COC expansion and HA synthesis were similar to those of FSH, suggesting that the effects of FSH are mediated by cAMP. However, FSH significantly decreased the specific activity of the incorporated hexosamines while Bt2cAMP did not. Serum is necessary for the accumulation of HA in the COC matrix. HA synthesis in FSH-stimulated COCs was as high or higher in the absence of serum, but most was recovered in the medium and not in the COC matrix. The molecular size of the HA was greater than 2 million dalton in either case, suggesting that the serum did not alter physical properties of HA. Stimulation of proteoglycan biosynthesis by either FSH or Bt2cAMP was less pronounced (three to four times control) than for HA and was sustained throughout an 18-h culture period. A reduction of 80% in the deposition of newly synthesized PGs in the COC matrix by 0.5 mM beta-xyloside treatment did not affect the expansion of the cumulus.
Publication
Journal: Journal of Neuroscience
August/23/2010
Abstract
The hypothalamic peptide, nesfatin-1, derived from the precursor NEFA/nucleobindin 2 (NUCB2), was recently identified as anorexigenic signal, acting in a leptin-independent manner. Yet its participation in the regulation of other biological functions gated by body energy status remains unexplored. We show herein that NUCB2/nesfatin-1 is involved in the control of female puberty. NUCB2/nesfatin mRNA and protein were detected at the hypothalamus of pubertal female rats, with prominent signals at lateral hypothalamus (LHA), paraventricular (PVN), and supraoptic (SON) nuclei. Hypothalamic NUCB2 expression raised along pubertal transition, with detectable elevations of its mRNA levels at LHA, PVN, and SON, and threefold increase of its total protein content between late-infantile and peripubertal periods. Conditions of negative energy balance, such as 48 h fasting or sustained subnutrition, decreased hypothalamic NUCB2 mRNA and/or protein levels in pubertal females. At this age, central administration of nesfatin-1 induced modest but significant elevations of circulating gonadotropins, whose magnitude was notably augmented in conditions of food deprivation. Continuous intracerebroventricular infusion of antisense morpholino oligonucleotides (as-MONs) against NUCB2 along pubertal maturation, which markedly reduced hypothalamic NUCB2 protein content, delayed vaginal opening and decreased ovarian weights and serum luteinizing hormone (LH) levels. In contrast, in adult female rats, intracerebroventricular injection of nesfatin did not stimulate LH or follicle-stimulating hormone secretion; neither did central as-MON infusion alter preovulatory gonadotropin surges, despite suppression of hypothalamic NUCB2. In sum, our data are the first to disclose the indispensable role of NUCB2/nesfatin-1 in the central networks driving puberty onset, a function that may contribute to its functional coupling to energy homeostasis.
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