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Publication
Journal: Journal of Biological Chemistry
October/16/1986
Abstract
One isoform of the regulatory subunit of type II cAMP-dependent protein kinase (R-II51; Mr = 51,000) and its electrophoretic variants (R-II51.5 and R-II52; Mr = 51,500 and 52,000, respectively) are selectively induced by estradiol and follicle-stimulating hormone (cAMP) in rat ovarian granulosa cells. To ascertain the amino acid sequence of R-II51 and to gain insight into the molecular events regulating the intracellular content of ovarian follicular R-II51, we constructed a lambda gt11 cDNA expression library from poly(A)+ RNA of hormone-primed rat granulosa cells. A 1.5-kilobase (kb) cDNA insert, isolated from a plaque-purified R-II antibody positive bacteriophage clone, selectively bound R-II51 mRNA as demonstrated by analysis of the hybrid-selected translation product. Restriction maps and sequence analyses of the 1.5-kb cDNA insert and of the 1.8- and 2.2-kb cDNA inserts from two additional clones showed overlapping sequences which span a region of 3065 nucleotides in size. The 1.5- and 1.8-kb cDNA inserts each contained poly(A) addition signals (1508 and 1761 nucleotides, respectively), terminal poly(A) sequences, and the entire coding region for R-II51 (1204 nucleotides) except for a small number of nucleotides at the 5' end. The 2.2-kb cDNA insert contained 394 nucleotides of the coding region a long 3' untranslated region and two more poly(A) addition signals (3041 and 3059 nucleotides). An amino acid microsequence surrounding the autophosphorylation site of pure rat ovarian R-II51 agreed with the amino acid sequence deduced from the nucleotide sequence of the cDNA. Northern blot analyses demonstrated two major mRNA species (1.8 and 3.2 kb in size) in hormone-primed rat ovaries which were approximately 10- and 50-fold greater than the R-II mRNA content in rat brain and rat heart, respectively. Southern blot analysis of rat liver DNA indicated that a single gene codes for R-II51 mRNA. Structural differences among rat ovarian R-II51, rat heart R-II54, and the known amino acid sequences of bovine R-II and R-I subunits also indicate that the rat ovarian R-II51 subunit is the product of a distinct gene.
Publication
Journal: Steroids
June/27/2012
Abstract
Polycystic ovarian syndrome (PCOS) is a common disorder characterized by ovulatory dysfunction and hyperandrogenemia (HA). Neuroendocrine abnormalities including increased gonadotropin-releasing hormone (GnRH) pulse frequency, increased luteinizing hormone (LH) pulsatility, and relatively decreased follicle stimulating hormone contribute to its pathogenesis. HA reduces inhibition of GnRH pulse frequency by progesterone, causing rapid LH pulse secretion and increasing ovarian androgen production. The origins of persistently rapid GnRH secretion are unknown but appear to evolve during puberty. Obese girls are at risk for HA and develop increased LH pulse frequency with elevated mean LH by late puberty. However, even early pubertal girls with HA have increased LH pulsatility and enhanced daytime LH pulse secretion, indicating the abnormalities may begin early in puberty. Decreasing sensitivity to progesterone may regulate normal maturation of LH secretion, potentially related to normally increasing levels of testosterone during puberty. This change in sensitivity may become exaggerated in girls with HA. Many girls with HA-especially those with hyperinsulinemia-do not exhibit normal LH pulse sensitivity to progesterone inhibition. Thus, HA may adversely affect LH pulse regulation during pubertal maturation leading to persistent HA and the development of PCOS.
Publication
Journal: Biology of Reproduction
November/29/2012
Abstract
New data have challenged the convention that the adult Sertoli cell population is fixed and unmodifiable. The Sertoli cell has two distinct functions: 1) formation of the seminiferous cords and 2) provision of nutritional and structural support to developing germ cells. For these to occur successfully, Sertoli cells must undergo many maturational changes between fetal and adult life, the main switches occurring around puberty, including the loss of proliferative activity and the formation of the blood-testis barrier. Follicle-stimulating hormone plays a key role in promoting Sertoli cell proliferation, while thyroid hormone inhibits proliferative activity in early postnatal life. Together these regulate the Sertoli-germ cell complement and sperm output in adulthood. By puberty, the Sertoli cell population is considered to be stable and unmodifiable by hormones. But there is mounting evidence that the size of the adult Sertoli cell population and its maturational status is modifiable by hormones and that Sertoli cells can gain proliferative ability in the spermatogenically disrupted hamster and human model. This new information demonstrates that the adult Sertoli cell population, at least in the settings of testicular regression in the hamster and impaired fertility in humans in vivo and from mice and men in vitro, is not a terminally differentiated population. Data from the hamster now show that the adult Sertoli cell population size is regulated by hormones. This creates exciting prospects for basic and clinical research in testis biology. The potential to replenish an adult Sertoli-germ cell complement to normal in a setting of infertility may now be realized.
Publication
Journal: Molecular and Cellular Biology
July/19/2007
Abstract
The gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are produced in the embryonic pituitary in response to delivery of the hypothalamic gonadotropin releasing hormone (GnRH). GnRH has a pivotal role in reestablishing gonadotropin levels at puberty in primates, and for many species with extended reproductive cycles, these are reinitiated in response to central nervous system-induced GnRH release. Thus, a clear role is evident for GnRH in overcoming repression of these genes. Although the mechanisms through which GnRH actively stimulates LH and FSH beta-subunit (FSHbeta) gene transcription have been described in some detail, there is currently no information on how GnRH overcomes repression in order to terminate reproductively inactive stages. We show here that GnRH overcomes histone deacetylase (HDAC)-mediated repression of the gonadotropin beta-subunit genes in immature gonadotropes. The repressive factors associated with each of these genes comprise distinct sets of HDACs and corepressors which allow for differentially regulated derepression of these two genes, produced in the same cell by the same regulatory hormone. We find that GnRH activation of calcium/calmodulin-dependent protein kinase I (CaMKI) plays a crucial role in the derepression of the FSHbeta gene involving phosphorylation of several class IIa HDACs associated with both the FSHbeta and Nur77 genes, and we propose a model for the mechanisms involved. In contrast, derepression of the LH beta-subunit gene is not CaMK dependent. This demonstration of HDAC-mediated repression of these genes could explain the temporal shut-down of reproductive function at certain periods of the life cycle, which can easily be reversed by the actions of the hypothalamic regulatory hormone.
Publication
Journal: Molecular Reproduction and Development
December/1/2010
Abstract
In poikilothermic vertebrates, sex determination is sometimes influenced by environmental factors such as temperature. However, little is known about the molecular mechanisms underlying environmental sex determination. The medaka (Oryzias latipes) is a teleost fish with an XX/XY sex determination system. Recently, it was reported that XX medaka can be sex-reversed into phenotypic males by high water temperature (HT; 32-34 degrees C) treatment during the sex differentiation period. Here we report that cortisol caused female-to-male sex reversal and that metyrapone (an inhibitor of cortisol synthesis) inhibited HT-induced masculinization of XX medaka. HT treatment caused elevation of whole-body levels of cortisol, while metyrapone suppressed the elevation by HT treatment during sexual differentiation. Moreover, cortisol and 33 degrees C treatments inhibited female-type proliferation of germ cells as well as expression of follicle-stimulating hormone receptor (fshr) mRNA in XX medaka during sexual differentiation. These results strongly suggest that HT induces masculinization of XX medaka by elevation of cortisol level, which, in turn, causes suppression of germ cell proliferation and of fshr mRNA expression.
Publication
Journal: Biochemistry
August/30/2006
Abstract
Follicle stimulating hormone (FSH) is one of the important hormones that regulate gonadal functions. This hormone is glycosylated, and the glycans greatly influence the biological properties. In the present study the negatively charged glycopeptides of equine and human pituitary follicle stimulating hormone (eFSH and hFSH) have been characterized in a glycosylation site-specific manner using FT-ICR-MS and Edman sequencing. The characteristic pattern of glycan distribution at each glycosylation site has been deduced and compared between horse and human FSH preparations. The data suggest that site-specific differences exist between glycoforms of human and equine FSH. For instance, except for one site in the beta subunit (Asn7) of hFSH all other sites in both species have sulfated glycoforms. Also, glycoforms at Asn52 of hFSH are all complex type, whereas in eFSH, both complex and hybrid structures exist at this site. There is also a higher percentage of sulfated glycans in the latter site compared to the former. This is the first study that characterizes the glycans from this hormone in a glycosylation site-specific manner, and these data can be used to begin correlative studies between glycosylation structure and hormone function.
Publication
Journal: Cancer Research
September/14/2009
Abstract
Chemotherapy is an important treatment for ovarian cancer. However, conventional chemotherapy has inevitable drawbacks due to side effects from nonspecific biodistribution of the chemotherapeutic drugs. To solve such problem, targeted delivery approaches were developed. The targeted delivery approaches combine drug carriers with the targeting system and can preferentially bring drugs to the targeted sites. Follicle-stimulating hormone receptor (FSHR) is an ovarian cancer-specific receptor. By using a peptide derived from FSH (amino acids 33-53 of the FSH beta chain, named as FSH33), we developed a conjugated nanoparticle, FSH33-NP, to target FSHR in ovarian cancer. FSH33-NP was tested for recognition specificity and uptake efficiency on FSHR-expressing cells. Then, the antitumor efficiency of paclitaxel (PTX)-loaded FSH33-NP (FSH33-NP-PTX) was determined. FSH33-NP-PTX displayed stronger antiproliferation and antitumor effects compared with free PTX or naked PTX-loaded nanoparticles (NP-PTX) both in vitro and in vivo. In summary, this novel FSH33-NP delivery system showed very high selectivity and efficacy for FSHR-expressing tumor tissues. Therefore, it has good potential to become a new therapeutic approach for patients with ovarian cancer.
Publication
Journal: Journal of Urology
July/7/2013
Abstract
OBJECTIVE
We investigated the effects of the administration of ubiquinol (a reduced form of coenzyme Q(10)) on semen parameters and seminal plasma antioxidant capacity in infertile men with idiopathic oligoasthenoteratozoospermia.
METHODS
A total of 228 men with unexplained infertility were randomly assigned 1:1 into 2 groups. Group 1 (114) received 200 mg ubiquinol daily by mouth for 26 weeks and group 2 (114) received a similar regimen of placebo. After completion of the 26-week treatment phase, all participants were followed for another 12-week off-drug period. Primary outcomes were improvement in sperm density, sperm motility and sperm strict morphology.
RESULTS
At the end of the 26-week treatment period mean ± SD sperm density in the ubiquinol and placebo groups was 28.7 ± 4.6 × 10(6)/ml and 16.8 ± 4.4 × 10(6)/ml (p = 0.005), sperm motility was 35.8% ± 2.7% and 25.4% ± 2.1% (p = 0.008), and sperm strict morphology was 17.6% ± 4.4% and 14.8% ± 4.1% (p = 0.01) of normal sperm, respectively. During the treatment period serum follicle-stimulating hormone levels decreased significantly (p = 0.02) and serum inhibin B concentrations increased significantly (p = 0.01). During the off-drug period semen parameters gradually returned to baseline values but the differences were still significant for sperm density (p = 0.03) and sperm motility (p = 0.03). The correlation coefficients analysis revealed a positive association between the duration of treatment with ubiquinol and sperm density (r = 0.74, p = 0.017), sperm motility (r = 0.66, p = 0.024) and sperm morphology (r = 0.57, p = 0.027).
CONCLUSIONS
Ubiquinol was significantly effective in men with unexplained oligoasthenoteratozoospermia for improving sperm density, sperm motility and sperm morphology.
Publication
Journal: Archives of Disease in Childhood
November/17/1992
Abstract
Endocrine function was assessed in 31 children (17 boys) after fractionated total body irradiation used in the preparative regimen for bone marrow transplantation. Endocrine dysfunction was present in 25 children. Fifteen of 29 had growth hormone insufficiency 0.9-4.9 years after total body irradiation, yet only three of the 15 had received previous cranial irradiation. Five of 30 had thyroid dysfunction: two with a low thyroxine and raised thyroid stimulating hormone (TSH) concentration and three with a raised TSH and normal thyroxine concentration. Thus the incidence of thyroid dysfunction (16%) is much lower than that reported after single fraction total body irradiation (39-59%). In only two children were abnormalities of the hypothalamic-pituitary-adrenal axis demonstrated. The majority of pubertal children assessed (n = 15) showed evidence of gonadal damage. All the pubertal girls (n = 5) had ovarian failure, although there was evidence of recovery of ovarian function in one girl. All seven boys in late puberty showed evidence of damage to the germinal epithelium, and two of three in early puberty had raised follicle stimulating hormone concentrations. Despite the use of a fractionated total body irradiation regimen, endocrine morbidity is substantial and children undergoing such procedures will require long term endocrine review and management.
Publication
Journal: Intensive Care Medicine
November/15/2004
Abstract
OBJECTIVE
To investigate the incidence and type of endocrine abnormalities in critical care patients with traumatic brain injury (TBI) and to examine their relationships to possible predisposing factors.
METHODS
Prospective study.
METHODS
General intensive care unit in a university hospital.
METHODS
Thirty-four TBI patients (27 men, 7 women), having a mean age of 37+/-16 years, were studied after weaning from mechanical ventilation.
METHODS
Baseline endocrine assessment was carried out by measuring cortisol, corticotropin, dehydroepiandrosterone sulfate, free thyroxine, thyrotropin (TSH), testosterone, oestradiol, follicle stimulating hormone (FSH), luteinizing hormone, prolactin, growth hormone and insulin-like growth factor I. Dynamic evaluation was performed by human corticotropin releasing hormone and growth hormone releasing hormone in all patients. Male patients underwent additional investigation with gonadotropin-releasing hormone. Severity of neurological derangement was graded according to Glasgow Coma Scale (GCS), Marshall Computerized Tomographic Classification and intracranial pressure (ICP) levels.
RESULTS
Eighteen of the 34 patients (53%) had an abnormal result in at least one hormonal axis tested, with cortisol hyporesponsiveness and gonadal dysfunction being equally common, affecting 24% of patients. Endocrine abnormalities were associated with a higher brain CT-scan classification score ( p=0.02). The GCS on admission correlated positively with baseline FSH (r=0.37, p=0.03), peak FSH (r=0.41, p=0.03), testosterone (r=0.44, p=0.02) and TSH (r=0.39, p=0.03). There were no relations between ICP(max) and any baseline or dynamic hormone measurements.
CONCLUSIONS
Patients with TBI receiving critical care show changes in their neuroendocrine responses, which depend upon clinical and radiological measures of head injury severity. Most common abnormalities include cortisol hyporesponsiveness and hypogonadism.
Publication
Journal: The Quarterly journal of medicine
June/1/1976
Abstract
The clinical features and hormonal abnormalities were surveyed in 117 men with cirrhosis of the liver. Compared with healthy men of similar ages, the patients had significantly lower metabolic clearance rates, plasma production rates and total and free levels of testosterone, reduced testosterone responses to human chorionic gonadotrophin stimulation, higher oestradiol, luteinizing hormone and follicle stimulating hormone levels and higher binding capacities of sex steroid binding globulin. The peripheral conversion of testosterone to oestradiol was also found to be significantly increased. However, the metabolic clearance and plasma production rates of oestradiol were not significantly different from those of healthy men. Patients who were severely ill with liver failure and one with haemochromatosis had low levels of luteinizing hormone and follicle stimulating hormone and sub-normal responses to clomiphene and luteinizing hormone-releasing hormone. Higher plasma oestradiol levels were found in patients with gynaecomastia and spider naevi than in those without these signs. However, the clinical features of androgen deficiency--that is, testicular atrophy, impotence and loss of secondary sex hair--were only poorly related to the low testosterone levels, and production rates and longtitudinal studies indicated that the hormonal levels, endocrine features and severity of the liver disease could change independently. It is concluded that the clearance of oestradiol from plasma is not limited by liver disease in all patients, and that reduced degradation of oestrogens is not the initial event in the sequence leading to the hormonal abnormalities of cirrhosis. While gonadotrophin deficiency occurs with liver failure and in some patients with haemochromatosis, the more usual findings are of elevated gonadotrophin levels and a poor Leydig cell response to chorionic gonadotrophin. These suggest that the hypogonadism is primary in most patients with cirrhosis. The causes of the high oestradiol levels were not discovered. Increased peripheral conversion of precursors to oestradiol or increased testicular secretion of oestradiol are possibilities. The high binding capacities of sex steroid binding globulin were not significantly correlated with either the low testosterone or high oestradiol level and the cause of this abnormality remains uncertain. The low metabolic clearance rates of testosterone appeared to result from the increased plasma protein binding of testosterone. The discrepancies in the expected relationships between the hormone and clinical changes suggest that factors other than those studied are also involved in the genesis of the endocrine features of hepatic cirrhosis.
Publication
Journal: Nature
October/12/2017
Abstract
Menopause is associated with bone loss and enhanced visceral adiposity. A polyclonal antibody that targets the β-subunit of the pituitary hormone follicle-stimulating hormone (Fsh) increases bone mass in mice. Here, we report that this antibody sharply reduces adipose tissue in wild-type mice, phenocopying genetic haploinsufficiency for the Fsh receptor gene Fshr. The antibody also causes profound beiging, increases cellular mitochondrial density, activates brown adipose tissue and enhances thermogenesis. These actions result from the specific binding of the antibody to the β-subunit of Fsh to block its action. Our studies uncover opportunities for simultaneously treating obesity and osteoporosis.
Publication
Journal: Endocrinology
October/31/1984
Abstract
Proliferation of Sertoli cells in the rat testis occurs only during the perinatal period and is maximal during fetal life. This interval is thus of critical importance in establishing the complement of Sertoli cells that populates the adult testis. FSH has been implicated in this process, but direct evidence in support of its involvement is lacking. In the present study, we have used in vivo and in vitro approaches to determine whether FSH produced by the fetal pituitary has a role in regulating Sertoli cell division in the fetal testis of the rat. On day 18 of gestation, just before the onset of maximal Sertoli cell proliferation, fetuses were either decapitated in utero or given antiserum to FSH. Light microscope autoradiography was then used to compare uptake of [3H]thymidine by Sertoli cell nuclei in testes from decapitated or antiserum-treated fetuses to that in corresponding controls on the following day. Both treatments produced dramatic and equal reductions in the percentages of Sertoli cells preparing to divide on day 19, suggesting that FSH from the fetal pituitary stimulates Sertoli cell proliferation in fetal testes. The effect of FSH or (Bu)2cAMP on Sertoli cell proliferation was also studied in vitro by placing testes from intact or decapitated fetuses into organ culture, with or without exogenous hormone or cyclic nucleotide. In all cases, [3H]thymidine was present for the final 4 h of culture. When testes were placed into medium containing isotope immediately after their removal from the fetus, the difference in labeling between testes from intact and decapitated fetuses was similar to that measured in vivo. After testes from decapitated fetuses were cultured for 8 h with or without FSH or (Bu)2cAMP, labeling of Sertoli cells in the treated group increased markedly over that in untreated cultures. After 28 h of exposure to FSH or (Bu)2cAMP, labeling in testes from decapitated fetuses remained significantly higher than that in corresponding untreated controls. In contrast, when testes from intact rats were cultured for 8 h in the presence of either cAMP or FSH, (Bu)2cAMP, but not FSH, brought about an increase in the percentage of Sertoli cells labeled compared to the control value. However, after exposing these testes to either FSH or (Bu)2cAMP for 28 h, the percentage of Sertoli cells labeled was greatly enhanced. Taken together, the data obtained from these experiments identify FSH as a major factor in controlling expansion of the Sertoli cell population during fetal development of the rat.(ABSTRACT TRUNCATED AT 400 WORDS)
Authors
Publication
Journal: Molecular and Cellular Endocrinology
November/27/2000
Abstract
Autocrine, paracrine and endocrine factors are necessary for normal ovarian folliculogenesis. A number of studies have demonstrated that the pituitary hormones follicle stimulating hormone (FSH) and luteinizing hormone (LH) as well as granulosa cell-derived growth factors such as activins, inhibins, and kit ligand are necessary for follicle development. Recent knockout studies from our laboratory have demonstrated that mice lacking the pituitary proteins FSHbeta and activin receptor type II are infertile due to blocks at the pre-antral and antral follicle stages, respectively. Although the somatic cells of the ovary (the granulosa and theca cells) have long been implicated in ovarian function, only recently have we shown that the oocyte plays an essential role in controlling its own fate by influencing somatic cell functions. Mice lacking the oocyte-secreted growth factor, growth differentiation factor-9 (GDF-9), are infertile due to a block at the one-layer primary follicle stage, leading to secondary defects in thecal cell layer formation, oocyte growth and meiotic competence, and granulosa cell differentiation. Furthermore, using recombinant GDF-9, we demonstrate that GDF-9 also regulates cumulus expansion and expression of several key granulosa cell-specific genes. Thus, GDF-9 functions as an oocyte-secreted growth and differentiation factor during early and late folliculogenesis and at ovulation to regulate several key somatic cell functions essential for female reproduction.
Authors
Publication
Journal: Genomics
September/15/1996
Abstract
The structure and organization of the human follicle-stimulating hormone receptor (FSHR) gene were determined by either screening a phage library of human genomic DNA or applying the long PCR technique to amplify different exon pairs with their corresponding introns. The FSHR gene spans a region of 54 kb and consists of 10 exons and 9 introns. Most of the extracellular domain is encoded by 9 exons, ranging in length between 69 and 251 bp; the C-terminal part of the extracellular domain, the transmembrane domain, and the intracellular domain are encoded by the large exon 10 (1234 bp). Overall the gene encodes 695 amino acids. The structure of the human FSHR displays striking similarity to that of the previously characterized rat FSHR gene, with a high degree of conservation in exon sizes and exon/intron junctions.
Publication
Journal: Human Reproduction
June/9/1999
Abstract
The effect of extremes of body mass on ovulation is well recognized by clinicians. However, the effect of obesity and extreme underweight on the outcome of in-vitro fertilization (IVF) cycles has received relatively little attention. In a retrospective nested case-control study we examined the effect of the extremes of body mass index (BMI) on IVF-embryo transfer outcome at a university-based IVF unit. A total of 333 patients were included in the study; 76 obese patients (BMI>> 27.9) with 152 controls, and 35 underweight patients (BMI < 19) with 70 controls. The patients were matched with their controls in age +/- 1 year, day 3 follicle stimulating hormone (FSH) concentration, daily dose of gonadotrophin (+/- 37.25 IU), gonadotrophin preparation and the year of treatment. The following parameters were compared between the study and control groups: duration of administration and dose of gonadotrophin, number of follicles aspirated, number of eggs, fertilization rate, number of embryos, serum oestradiol concentration on human chorionic gonadotrophin (HCG) day (peak oestradiol), clinical pregnancy rate, implantation rate, miscarriage rate, and incidence of ovarian hyperstimulation syndrome. Apart from a significantly lower peak oestradiol concentration (P = 0.009) in the obese patients, they and the underweight patients were not significantly different from their normal controls. The extremes of body mass index do not adversely affect the outcome of IVF-embryo transfer treatment. However, the obese patients had lower peak oestradiol concentrations than their normal controls despite receiving similar gonadotrophin doses.
Publication
Journal: Zeitschrift fur Rheumatologie
April/6/1999
Abstract
To study the hormonal perturbations in FMS patients we injected sixteen FMS patients and seventeen controls a cocktail of the hypothalamic releasing hormones: Corticotropin-releasing hormone (CRH), Thyrotropin-releasing hormone (TRH), Growth hormone-releasing hormone (GHRH), and Luteinizing hormone-releasing hormone (LHRH) and observed the hormonal secretion pattern of the pituitary together with the hormones of the peripheral endocrine glands. We found in FMS patients elevated basal values of ACTH and cortisol, lowered basal values of insulin-like growth factor I (IGF-I) and of triiodothyronine (T3), elevated basal values of follicle-stimulating hormone (FSH) and lowered basal values of estrogen. Following injection of the four releasing-hormones, we found in FMS patients an augmented response of ACTH, a blunted response of TSH, while the prolactin response was exaggerated. The effects of LHRH stimulation were investigated in six FMS patients and six controls and disclosed a significantly blunted response of LH in FMS. We explain the deviations of hormonal secretion in FMS patients as being caused by chronic stress, which, after being perceived and processed by the central nervous system (CNS), activates hypothalamic CRH neurons. CRH, on the one hand, activates the pituitary-adrenal axis, but also stimulates at the hypothalamic level somatostatin secretion which, in turn, causes inhibition of GH and TSH at the pituitary level. The suppression of gonadal function may also be attributed to elevated CRH by its ability to inhibit hypothalamic LHRH release, although it could act also directly on the ovary by inhibiting FSH-stimulated estrogen production. We conclude that the observed pattern of hormonal deviations in FMS patients is a CNS adjustment to chronic pain and stress, constitutes a specific entity of FMS, and is primarily evoked by activated CRH neurons.
Publication
Journal: Human Reproduction
September/7/1993
Abstract
To assess the risk of miscarriage after in-vitro fertilization (IVF) with respect to age, cause of infertility, ovarian morphology and treatment regimen, a retrospective analysis was performed of the first 1060 pregnancies conceived between June 1984 and July 1990 as a result of 7623 IVF cycles. Superovulation induction was achieved with human menopausal gonadotrophin (HMG) and/or purified follicle stimulating hormone (FSH) together with either clomiphene citrate or the gonadotrophin hormone-releasing hormone (GnRH) agonist buserelin, the latter either as a short 'flare' regimen or as a 'long' regimen to induce pituitary desensitization. There were 282 spontaneous abortions (26.6%) and 54 ectopic pregnancies (5.1%). The mean age of women with ongoing pregnancies was 32.2 (SD 3.9) years compared with 33.2 (SD 4.1) years in those who miscarried, which were significantly different (P = 0.008). There was no relation between the miscarriage rate and the indication for IVF. The miscarriage rate was 23.6% in women with normal ovaries compared with 35.8% in those with polycystic ovaries [P = 0.0038, 95% confidence interval (CI) 4.68-23.10%]. There was no difference in the miscarriage rate between treatment with HMG or FSH. Women whose ovaries were normal on ultrasound were just as likely to miscarry if they were treated with clomiphene or with the long buserelin protocol. Those with polycystic ovaries, however, had a significant reduction in the rate of miscarriage when treated with the long buserelin protocol, 20.3% (15/74), compared with clomiphene citrate, 47.2% (51/108) (P = 0.0003, 95% CI 13.82-40.09%).
Publication
Journal: Developmental Biology
March/29/2004
Abstract
In the ovarian follicle, anti-Müllerian hormone (Amh) mRNA is expressed in granulosa cells from primary to preovulatory stages but becomes restricted to cumulus cells following antrum formation. Anti-Müllerian hormone regulates follicle development by attenuating the effects of follicle stimulating hormone on follicle growth and inhibiting primordial follicle recruitment. To examine the role of the oocyte in regulating granulosa cell Amh expression in the mouse, isolated oocytes and granulosa cells were co-cultured and Amh mRNA levels were analysed by real-time RT-PCR. Expression in freshly isolated granulosa cells increased with preantral follicle development but was low in the cumulus and virtually absent in the mural granulosa cells of preovulatory follicles. When preantral granulosa cells were co-cultured with oocytes from early preantral, late preantral or preovulatory follicles, and when oocytes from preovulatory follicles were co-cultured with cumulus granulosa cells, Amh expression was increased at least 2-fold compared with granulosa cells cultured alone. With oocytes from preantral but not preovulatory follicles, this was a short-range effect only observed with granulosa cells in close apposition to oocytes. We conclude that stage-specific oocyte regulation of Amh expression may play a role in intra- and inter-follicular coordination of follicle development.
Publication
Journal: Molecular and Cellular Biology
May/16/2001
Abstract
Male mice lacking both the Ink4c and Ink4d genes, which encode two inhibitors of D-type cyclin-dependent kinases (Cdks), are infertile, whereas female fecundity is unaffected. Both p18(Ink4c) and p19(Ink4d) are expressed in the seminiferous tubules of postnatal wild-type mice, being largely confined to postmitotic spermatocytes undergoing meiosis. Their combined loss is associated with the delayed exit of spermatogonia from the mitotic cell cycle, leading to the retarded appearance of meiotic cells that do not properly differentiate and instead undergo apoptosis at an increased frequency. As a result, mice lacking both Ink4c and Ink4d produce few mature sperm, and the residual spermatozoa have reduced motility and decreased viability. Whether or not Ink4d is present, animals lacking Ink4c develop hyperplasia of interstitial testicular Leydig cells, which produce reduced levels of testosterone. The anterior pituitary of fertile mice lacking Ink4c or infertile mice doubly deficient for Ink4c and Ink4d produces normal levels of luteinizing hormone (LH). Therefore, the failure of Leydig cells to produce testosterone is not secondary to defects in LH production, and reduced testosterone levels do not account for infertility in the doubly deficient strain. By contrast, Ink4d-null or double-null mice produce elevated levels of follicle-stimulating hormone (FSH). Because Ink4d-null mice are fertile, increased FSH production by the anterior pituitary is also unlikely to contribute to the sterility observed in Ink4c/Ink4d double-null males. Our data indicate that p18(Ink4c) and p19(Ink4d) are essential for male fertility. These two Cdk inhibitors collaborate in regulating spermatogenesis, helping to ensure mitotic exit and the normal meiotic maturation of spermatocytes.
Publication
Journal: Menopause
July/11/2007
Abstract
OBJECTIVE
Women approaching menopause often ask their doctors, "When are my periods going to end?" The objective of this study was to predict time to the final menstrual period (FMP).
METHODS
This multiethnic, observational cohort study, the Study of Women's Health Across the Nation, has been ongoing since 1996. Data collected from seven annual study visits were used. The community-based cohort from seven national sites included 3,302 white, African American, Hispanic, Chinese, and Japanese women aged 42 to 52 years at baseline with a uterus and at least one ovary, who were not pregnant or taking reproductive hormones, and had at least one menstrual period within the past 3 months at baseline. The time to the FMP was defined retrospectively after 12 months of amenorrhea. Uni- and multivariable Cox proportional hazard models, hazard ratios (HRs), and 95% CIs were computed for variables of interest.
RESULTS
A total of 2,662 women, of whom 706 had an observed FMP, were included. Age, menstrual cycles that had become farther apart (HR = 2.56, 95% CI = 1.94-3.39) or more variable (HR = 1.79, 95% CI = 1.45-2.21), and current smoking (HR = 1.68, 95% CI = 1.35-2.08) were all associated with shorter time to the FMP. Higher (log) follicle-stimulating hormone (HR = 2.32, 95% CI = 2.02-2.67) was related to a shorter time to the FMP, but the highest estradiol category >>or=100 pg/mL [367 pmol/L]) was associated with an earlier onset of the FMP (HR = 2.16, 95% CI = 1.63-2.89). The number of vasomotor symptoms was related to an earlier FMP, whereas higher physical activity and educational levels were associated with a later FMP.
CONCLUSIONS
Age, menstrual cycle recall, smoking status, and hormone measurements can be used to estimate when the FMP will occur, allowing for more precise estimates for older midlife women: in the most extreme cases, ie, age 54, high estradiol level, current smoking, and high follicle-stimulating hormone level, the FMP can be estimated to within 1 year.
Publication
Journal: The American journal of physiology
June/2/1999
Abstract
The neuroendocrine mechanisms by which estradiol drives growth hormone (GH) secretion in the human are poorly defined. Here we investigate estrogen's specific regulation of the 24-h pulsatile, nyctohemeral, and entropic modes of GH secretion in healthy postmenopausal women. Volunteers (n = 9) received randomly ordered placebo versus estradiol-17beta (1 mg micronized steroid twice daily orally) treatment for 7-10 days and underwent blood sampling at 10-min intervals for 24 h to capture GH release profiles quantitated in a high-sensitivity chemiluminescence assay. Pulsatile GH secretion was appraised via deconvolution analysis, nyctohemeral GH rhythms by cosinor analysis, and the orderliness of GH release patterns via the approximate entropy statistic. Mean (+/-SE) 24-h serum GH concentrations approximately doubled on estrogen treatment (viz., from 0.31 +/- 0.03 to 0.51 +/- 0.07 microgram/l; P = 0.033). Concomitantly, serum insulin-like growth factor-I (IGF-I), luteinizing hormone, and follicle-stimulating hormone concentrations fell, whereas thyroid-stimulating hormone and prolactin levels rose (P < 0.01). The specific neuroendocrine action of estradiol included 1) a twofold amplified mass of GH secreted per burst, with no significant changes in basal GH release, half-life, pulse frequency, or duration; 2) an augmented amplitude and mesor of the 24-h rhythm in GH release, with no alteration in acrophase; and 3) greater disorderliness of GH release (higher approximate entropy). These distinctive and dynamic reactions to estrogen are consistent with partial withdrawal of IGF-I's negative feedback and/or accentuated central drive to GH secretion.
Publication
Journal: Clinical Endocrinology
May/8/2000
Abstract
OBJECTIVE
To determine whether mutations in the FSH receptor gene are associated with premature ovarian failure (POF) or resistant ovary syndrome (ROS) in women in the UK. To determine whether an allelic variant of the FSH receptor gene affects fertility parameters in women with polycystic ovary syndrome (PCOS).
METHODS
A mutation screen using DNA from women with POF and ROS. Restriction digest of amplified DNA from women with POF, ROS, PCOS and controls to determine allelic variant status. Fertility parameters were compared between allelic variant subgroups of women with PCOS.
METHODS
The study population comprised 49 women with POF, 5 with ROS, 93 with PCOS and 51 controls.
METHODS
In women with PCOS, fertility and menstrual status was recorded and serum FSH and ovarian volume were measured.
RESULTS
No mutation of the FSH receptor gene was found in women with POF or ROS. The allelic variant Thr307/Ser680 was found to be similarly prevalent in all study groups. The Thr307/Ser680 variant was found to have no phenotype in terms of fertility parameters in women with PCOS.
CONCLUSIONS
Mutations of the FSH receptor gene are rare in women with premature ovarian failure or resistant ovary syndrome in the UK. Polymorphisms of the FSH receptor gene do not appear to have pathophysiological significance with regard to ovarian function.
Publication
Journal: Endocrinology
July/23/2007
Abstract
Osteoporosis is a leading public health problem. Although a major cause in women is thought to be a decline in estrogen, it has recently been proposed that FSH or follitropin is required for osteoporotic bone loss. We examined the FSH receptor null mouse (FORKO mouse) to determine whether altered ovarian function could induce bone loss independent of FSH action. By 3 months of age, FORKO mice developed age-dependent declines in bone mineral density and trabecular bone volume of the lumbar spine and femur, which could be partly reversed by ovarian transplantation. Bilateral ovariectomy reduced elevated circulating testosterone levels in FORKO mice and decreased bone mass to levels indistinguishable from those in ovariectomized wild-type controls. Androgen receptor blockade and especially aromatase inhibition each produced bone volume reductions in the FORKO mouse. The results indicate that ovarian secretory products, notably estrogen, and peripheral conversion of ovarian androgen to estrogen can alter bone homeostasis independent of any bone resorptive action of FSH.
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