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PubMed1994

Ooplasmectomy has no influence on FSH-induced expansion of bovine cumulus investment in vitro.

Bovine cumulus-oocyte complexes with or without attached pieces of the mural stratum granulosum were matured with or without FSH in vitro for 24 h. Some complexes were ooplasmectomized (removal of ooplasm) at the onset of culture or after 9 h of culture, and in others the complete oocyte, including the zona pellucida, was removed. At the end of culture, the degree and morphology of corona and cumulus expansion were determined by a subjective scoring system, transmission electron microscopy followed by computerized image analysis, or scanning electron microscopy. In the absence of FSH no expansion was seen. In the presence of FSH, hyaluronidase-sensitive cumulus expansion was observed in intact complexes and complexes ooplasmectomized after 9 h of culture. In complexes ooplasmectomized at the start of culture, hyaluronidase-insensitive expansion of the corona compartment was seen as well. A similar reaction was found in free corona and cumulus cell masses cultured in the presence or absence of oocytes. Mural granulosa in intact and ooplasmectomized complexes expanded only slightly under the influence of FSH and exhibited no hyaluronidase sensitivity. Ooplasmectomy at the start of culture increased the frequency of ruffled cell membranes and decreased the occurrence of intercellular bridges as compared with unmanipulated complexes cultured under corresponding conditions. It is concluded that FSH-induced cumulus expansion and hyaluronidase-sensitive extracellular mucus production of bovine cumulus investment in vitro are not dependent on the oocyte, except for minor changes in the surface morphology of the cumulus cells.

Animals↗
PubMed1981

Evidence for FSH-like material in ACTH granules of certain corticotropic cells in the pituitary of the pig.

The ultrastructural immunocytochemical peroxidase-antiperoxidase technique used on serial sections reveals that certain corticotropic cells contain both ACTH and FSH beta, but not LH beta (ACTH/FSH cells). To determine the specificity of the anti-FSH beta staining in these cells, immunocytochemical absorption experiments were performed. The results indicate that (1) anti-FSH beta and -ACTH antisera are bound to different antigens in the corticotropic cell, and (2) anti-FSH beta staining is specific for a FSH-like antigen. In the ACTH/FSH cells both hormones are stored in the same secretory granules, distributed among other granules that contain only ACTH.

Adrenocorticotropic Hormone↗
PubMed1988

Spontaneous luteinizing hormone (LH) surges are associated with more rapidly increasing estradiol (E2) and follicle stimulating hormone (FSH) in in vitro fertilization and embryo transfer.

In a retrospective analysis of 64 patients stimulated with human menopausal gonadotropin (hMG) and/or pure follicle stimulating hormone (FSH); 35 cycles with spontaneous luteinizing hormone (LH) surges were compared with 29 control cycles with respect to serum FSH and estradiol (E2) levels drawn on the day prior to and the day of human chorionic gonadotropin (hCG), approximately 16 hr after gonadotropin stimulation. FSH decreased significantly (P less than 0.05) in control cycles where two or more preovulatory oocytes (preovs) were obtained, in contrast to cycles with a spontaneous LH surge, where FSH increased irrespective of the number of preovs. The E2 increase in the LH surge cycles was significantly higher (P less than 0.05) than in the control cycles. However, the increase in E2 did not correlate with the change in FSH levels or with the number of preovs.

Chorionic Gonadotropin↗
PubMed1996

Hypersecretion of follicle-stimulating hormone (FSH) on estrous afternoon in rats treated with RU486 in proestrus.

1. Intact or ovariectomized (OVX) cyclic rats injected or not with RU486 (4 mg/0.2 ml oil) from proestrus onwards were bled at 0800 and 1800 h on proestrus, estrus and metestrus. Additional RU486-treated rats were injected with: LHRH antagonist (LHRHa), estradiol benzoate (EB) or bovine follicular fluid (bFF) and sacrificed at 1800 h in estrous afternoon. LH and FSH serum levels were determined by RIA. 2. RU486-treated intact or OVX rats had decreased preovulatory surges of LH and FSH, abolished secondary secretion of FSH and hypersecretion of FSH in estrous afternoon. The latter was decreased by LHRHa and abolished by EB or bFF. In contrast, EB induced an hypersecretion of LH in RU486-treated rats at 1800 h in estrus. 3. It can be concluded that in the absence of the proestrous progesterone actions, the absence of the inhibitory effect of the ovary in estrus evoked a LHRH independent secretion of FSH.

Animals↗
PubMedDate not supplied

Role of intron 5 C/T polymorphism of the calcium sensing receptor gene in the regulation of the serum FSH and LH in post-menopausal women.

OBJECTIVE: High extracellular calcium concentration (Cao(2+)) acts to inhibit calcium sensing receptor (CaR) signalling on cellular surfaces in parathyroid glands. This receptor is, however, also expressed on the membranes of some non-calciotropic endocrine cells, including pituitary-derived cells. The aim of our study was to analyse relationships between the CaR gene and the circulating FSH and LH in normal post-menopausal women. METHODS: A total of 95 untreated euparathyroid post-menopausal women were investigated in the study. The serum FSH and LH levels were evaluated in relationship to allele combinations of the CaR gene (C/T polymorphism in the intron 5 and A986S polymorphism in exon 7), using an analysis of co-variance (ANCOVA) model. RESULTS: Distribution of TT, TC and CC allele combinations (intron 5 C/T polymorphism) was 51, 43 and 6 %, respectively. Higher serum FSH and LH levels were found in carriers of C allele than in women without this allele (p < 0.002 and p < 0.03, respectively). No correlations were found between A986S polymorphism and serum FSH and LH levels. CONCLUSIONS: Serum FSH and LH levels are associated with intron 5 C/T (but not A986S) polymorphism of the CaR gene in untreated post-menopausal women. The physiological role of the CaR gene in the regulation of the gonadotropic function needs to be further investigated.

Adult↗
PubMed1987

Stimulation of FSH release by erythroid differentiation factor (EDF).

The action of erythroid differentiation factor (EDF) on primary culture of rat anterior pituitary cells was examined. EDF stimulates FSH secretion in a dose dependent manner but not of LH secretion. ED50 of EDF for FSH secretion was 5 X 10(-10) M, while ED50 of LHRH for FSH secretion was 5 X 10(-9) M. These data indicate that EDF is a potent agonist for FSH secretion and the biological activity of EDF on anterior pituitary seems to be identical as that of FSH releasing protein (FRP).

Activins↗
PubMed1989

The Drosophila fsh locus, a maternal effect homeotic gene, encodes apparent membrane proteins.

The maternal effect gene fsh is involved in the establishment of segments and the specification of their identities; the progeny of mutant females are missing portions of thoracic and abdominal segments, and may have homeotic transformations of third thoracic segments to second thoracic segments. The fsh locus interacts synergistically with loci such as Ubx and trx in the production of homeotic transformations. We have characterized cDNA clones corresponding to the major fsh transcripts expressed in ovaries and early embryos, and to a pupal transcript. The expression of fsh transcripts in ovaries is restricted to the germline; in developing embryos, transcripts are found throughout the cytoplasm. The different ovarian/embryonic transcripts (7.6 and 5.9 kb) are generated by use of alternative polyadenylation and splice sites. These transcripts encode two large predicted proteins of 110 and 205 kDa that have unusual amino acid compositions: 40% of the residues are glycine, alanine, or serine, and there are several regions of homopolymers and simple sequence repeats. Hydropathy analysis indicates that these proteins span the membrane. We suggest that the expression of fsh proteins in the membrane of the embryo is required for proper functioning of genes such as Ubx in the specification of segmental identity.

Amino Acid Sequence↗
PubMed1984

Effects of FSH on acidic nuclear protein synthesis in cultured pig Sertoli cells.

We studied the effect of FHS on nuclear protein synthesis by a primary culture of immature porcine Sertoli cells. The cells were cultured in a chemically defined medium and treated with FSH (50 ng/ml) for various periods (4, 8, 25 and 64 h). About 65 spots (pHi less than 8) were identified by two-dimensional polyacrylamide gel electrophoresis of the radiolabelled nuclear proteins. After 25 h of FSH treatment, we observed an increase of 5 proteins, a slight decrease of two and a disappearance of one. For the short periods of FSH treatment (4 and 8 h), no effect of FHS on nuclear protein synthesis was observed. After 64 h of FSH treatment (4 and 8 h), no effect of FHS on nuclear protein synthesis was observed. After 64 h of FSH treatment, the synthesis of all nuclear proteins appears to be decreased.

Animals↗
PubMed1987

Modulation of stimulatory action of follicle stimulating hormone (FSH) and inhibitory action of epidermal growth factor (EGF) on aromatase activity in Sertoli cells by calcium.

Aromatization of testosterone by cultured Sertoli cells isolated from immature rats was stimulated more than 7-fold by follicle stimulating hormone (FSH) or dcAMP. The effects of FSH and dcAMP could be partly inhibited by epidermal growth factor (EGF) in a dose-dependent manner (ID500.5 nM). The phorbol ester 4 beta-phorbol-12-myristate-13-acetate (PMA) could also inhibit aromatase activity in a fashion similar to EGF. When 3 mM EGTA was present in the culture medium, the inhibitory effect of EGF was abolished but the stimulatory effect of FSH or dcAMP was magnified. These results suggest that EGF exerts a negative control on aromatase via calcium and protein kinase C. The abolishment of the inhibitory effect of EGF and the enhancement of the stimulatory effect of FSH or dcAMP by a calcium deficiency may be an indication that growth factors produced by Sertoli cells negatively controls FSH-induced responses in an autocrine fashion.

1-Methyl-3-isobutylxanthine↗
PubMed1991

Differential appearance of the subunits of glycoprotein hormones (LH, FSH, and TSH) in the pituitary of bullfrog (Rana catesbeiana) larvae during metamorphosis.

The ontogeny of gonadotrophs and thyrotrophs in the bullfrog pituitary was examined immunohistochemically using monoclonal antibodies against bullfrog lutropin beta-subunit (LH beta), follitropin beta-subunit (FSH beta) and its alpha-subunit, and polyclonal anti-human thyrotropin beta-subunit (TSH beta) serum. Immunoreactive alpha-subunit- and TSH beta-, but not FSH beta- and LH beta-containing cells were observed at embryonic stage 24 (Shumway's classification). Immunoreactive FSH beta cells first appeared at Taylor-Korllos stage V, and immunoreactive LH beta cells at stage X. Throughout metamorphosis, several gonadotrophs containing both FSH and LH were found in the ventrocaudal region, but most gonadotrophs contained only FSH. Immunoreactive alpha-subunit cells were always more frequent than the sum of immunoreactive beta-subunit cells, which was confirmed by quantitative studies using immunohistochemical and RIA techniques.

Animals↗
PubMed1989

Signal transduction in the Sertoli cell: serum modulation of the response to FSH.

Immature Sertoli cells of the testicular seminiferous tubule maintain the expression of their differentiated phenotype when cultured in unsupplemented medium. In preliminary experiments we observed that foetal bovine serum (FBS) stimulates polyphosphoinositides (PI) hydrolysis in Sertoli cells. We then evaluated the effect of serum on the function of the immature Sertoli cell in culture, in terms of cAMP and estrogen production. Treatment of Sertoli cells for 30 min with 1-10% FBS had no effect on basal cAMP accumulation but abolished the response to FSH. The serum concentration producing half-maximal inhibition of the FSH-dependent cAMP accumulation was 0.5-1%. Comparison of the FSH-dose-response in the absence or presence of serum showed a decreased maximal response when serum was present. Sertoli cells exposed to serum were also less responsive to the beta-adrenergic agonist isoproterenol, to cholera toxin, and to forskolin. The serum inhibition was rapidly reversed upon removal of serum or incubating the cells with the phosphodiesterase inhibitor MIX (methyl-isobutyl-xanthine). Similarly to what observed with cAMP, serum affected androgen aromatization stimulated by FSH, isoproterenol, cholera toxin, forskolin and dibutyryl cAMP. These data indicate that factors present in serum can act as modulators of the Sertoli cell function in vitro by rapidly and reversibly inhibiting the cAMP and steroidogenic response of the Sertoli cell to FSH.

Animals↗
PubMed1990

De novo biosynthesis of FSH like peptide by the human prostate.

Human benign prostatic hyperplasia tissue is able to synthesize immunoreactive FSH (IR FSH) in vitro. The prostatic FSH is similar to pituitary FSH as evident by co-elution on Sephadex G-100. High performance gel filtration chromatography and Western blot analysis. Immunocytochemical localization studies indicate positive staining in the cytoplasm of prostatic epithelial cells. There is a two fold increase in the concentration of immunoreactive FSH in benign hyperplastic tissue as compared to normal prostate.

Blotting, Western↗
PubMed1994

FSH bioactivity is strongly enhanced by kinetic incubation of pre-antral hamster follicles.

UNLABELLED: Isolation of meiotic arrested oocytes from mammalian ovaries involves a resumption of the meiosis. Studying the effect of FSH on this process it was found that doses up to of 0.1 IU/ml did not maintain the meiotic arrest in hamster oocytes in pre-antral follicles during static incubation conditions. However, when the FSH medium was replaced at 120, 60 and 30 min the resumption of the meiosis gradually decreased. Using a replacement frequency of 30 min a complete log dose-curve was constructed (ED50: 0.5 mU/ml; minimum effective dose: 0.1 mU/ml). The lack of a FSH response during static incubation was not caused by exhaustion of its bioactivity: mixing of the FSH containing medium, obtained from a 4 hours' static incubation, resulted in an inhibition similar to the inhibition that occurred during the replacement procedure. IN CONCLUSION: FSH is able to maintain the meiotic arrest in pre-antral follicle enclosed oocytes at low doses only when the medium is in circulation.

Animals↗
PubMed1995

Immunoreactive inhibin decreases following bilateral ovariectomy and during the postovulatory rise of FSH in Syrian hamsters.

Inhibin is a heterodimeric glycoprotein which may regulate FSH synthesis and secretion as well as follicular development and maturation. The source and physiological role of inhibin have not been established for the hamster, although several investigators have suggested that this hormone may function in the regulation of FSH in this species. The major objectives of the present studies were to develop a radioimmunoassay (RIA) for the measurement of inhibin in hamster serum and tissue, to identify the primary source of inhibin and to examine the relationship between inhibin and FSH during the estrous cycle. A sensitive, accurate and specific RIA was developed and utilized to measure changes in circulating levels of immunoreactive inhibin (ir-inh-alpha) following bilateral gonadectomy and throughout the estrous cycle. Circulating ir-inh-alpha declined rapidly and significantly following bilateral gonadectomy in female hamsters suggesting a gonadal source. Serum FSH concentrations increased following the decline in serum ir-inh-alpha levels. In the adult female hamster circulating ir-inh-alpha increased gradually throughout diestrus, peaked at the time of the preovulatory gonadotropin surge, then declined to a nadir on the morning of estrus. Changes in ovarian inhibin subunit mRNAs were examined throughout the estrous cycle and correlated with changes observed in circulating ir-inh-alpha levels. Observed significant reductions in the relative amount of inhibin mRNAs and serum concentrations of ir-inh-alpha during early estrus may moderate the amount and duration of the secondary FSH rise and thus contribute to the regulation of follicle recruitment in the hamster.

Animals↗
PubMed1979

In vitro metabolism of testosterone by cultured Sertoli cells and the effect of FSH.

Cultures of Sertoli cells isolated from testes of 18-and 36-day-old Long Evans rats were used to investigate their capacity to metabolize testosterone and the effect of FSH on such metabolism. Three different approaches were used: 1) investigation of the metabolism of radiolabeled testosterone under saturating substrate conditions; 2) study of the metabolism of radiolabeled testosterone utilizing trace amounts of high specific activity substrates; 3) the utilization of radioimmunoassay for measurement of estradiol-17 beta. The following steroids were isolated and identified by recrystallization to constant specific acitvity from the control and FSH-treated cultures; testosterone (unconverted substrate), androstenedione, dihydrotestosterone, 3 alpha-hydroxy-5 alpha-androstan-17-one and 5 alpha-androstane-3 alpha, 17 beta-diol. Radioimmunoassay data suggests that the Sertoli cells produce an estradiol-17 beta-like compound from unlabeled testosterone and that this production is stimulated by FSH. However, the radioactive metabolite from all our studies that behaved chromatographically like estradiol--17 beta failed to crystallize to constant specific activity, while in each experiment, authentic radiolabeled estradiol-17 beta added as recovery tracer did. The data demonstrate that : 1) cultures of Sertoli cells from immature rats have 5 alpha-reductase, 3 alpha- and 17 beta-hydroxysteroid oxidoreductase activities; 2) these enzymes may be affected by FSH; 3) based on radiolabeled metabolic techniques, Sertoli cells were unable to biotransform testosterone to estradiol-17 beta even in the presence of FSH.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1989

Specific inhibition of FSH-stimulated cAMP accumulation by delta 9-tetrahydrocannabinol in cultures of rat Sertoli cells.

delta 9-Tetrahydrocannabinol (THC), the major psychoactive component in marihuana, is a reproductive toxicant in both man and animals. THC acts at both the level of the pituitary-hypothalamic axis and the testis, specifically the Leydig cell; an effect on the Sertoli cell has not been shown. Since THC inhibits cAMP accumulation in several cell types, we have examined the effect of THC on Sertoli cell function using altered cAMP accumulation as a marker of toxicity. THC reduced the FSH-induced accumulation of cAMP at concentrations which were neither cytotoxic nor affected cellular ATP levels. This inhibition was evident after 3 hr and did not affect the dose of FSH which gave half-maximal stimulation, suggesting that THC does not compete with FSH for binding to its receptor. The ability of THC to inhibit cAMP accumulation was not affected by incubation in the presence of phosphodiesterase inhibitors, making it unlikely that it acts via stimulation of phosphodiesterase activity. This THC-induced inhibition of Sertoli cell cAMP is specific for FSH; it does not affect the ability of forskolin, cholera toxin, isoproterenol, or prostaglandin E1 to stimulate Sertoli cell cAMP. Furthermore, inhibition occurs in the presence of pertussis toxin, suggesting that this effect of THC is independent of the inhibitory adenylate cyclase pathway. Inhibition of Sertoli cell cAMP also occurs with other cannabinoids which are present in marihuana, but which are not psychoactive. These data indicate that a part of the testicular toxicity of THC may be due to a specific alteration of the hormonal control of Sertoli cell function via an inhibition of FSH-stimulated cAMP accumulation.

Adenosine Triphosphate↗
PubMed1982

Inhibition and subsequent rebound of FSH secretion following treatment with bovine follicular fluid in the ewe.

Plasma concentrations of gonadotropins were examined after treatment of ewes with bovine follicular fluid (FF) in four experiments. Mean concentrations of FSH were significantly decreased by FF treatment. The FSH depression appeared to continue throughout the length of treatment when the duration of treatment was 2-4 days. However, in an experiment in which the treatment period was 8 days, mean concentrations of FSH initially declined and then returned to control levels during the last 4 days of treatment. In all experiments, a rebound in FSH concentrations was found 24-36 h after cessation of FF treatment. The magnitude of this rebound appeared to be proportional to the degree of FSH suppression during FF treatment.

Journal Article↗
PubMed1982

Serum FSH levels during estrus and a 4-week period following mating in Murrah buffaloes (Bubalus bubalis ).

Circulating FSH levels of 13 Murrah buffaloes were investigated by a double-antibody radioimmunoassay using a homologous bovine system. The mean (+/- s.e.m.) peak FSH level on the day of estrus was if57.94 +/- 12.84 ng/ml of blood serum during hotter months (June-August) and 65.23+/-10.54 ng/ml during cooler months (October-December). These were much higher than the FSH concentrations recorded during the rest of the cycle post-mating. There were sizable fluctuations in FSH levels on different days of the estrous cycle within animals. However, the mean values did not exhibit much variation. The occurrence of the FSH peak and the LH peak coincided during the cycle.

Journal Article↗