Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FSH”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMed2004

Differential FSH exposure in preantral follicle culture has marked effects on folliculogenesis and oocyte developmental competence.

BACKGROUND: We investigated at what stage early cultured preantral mouse follicles become dependent on a minimal effective FSH dose (10 mIU/ml) and analysed the influence of implementing FSH at several time-points during in vitro culture. METHODS: Two-layered mouse follicles were cultured for 12 days under seven different FSH exposure regimens and ovulated on day 13 by hCG/EGF. Ovulated cumulus-oocyte complexes were fertilized and embryos were cultured up to the blastocyst stage. RESULTS: When FSH was absent or added only once at the start of culture, follicle survival was significantly reduced (22 and 52% respectively versus 95% when FSH was continuously present, P < 0.01) and oocyte quality was compromised, providing few oocytes for embryo culture (19 and 7% versus 71% in continuous presence of FSH, P < 0.01). Optimal follicle survival rates can be ensured by implementing FSH at the latest from day 4 of culture. By introducing FSH later than day 4, follicle survival rates and number of ovulated oocytes decreased. Estradiol production and luteinization were strongly related to the moment of introducing FSH in culture. Fertilization and preimplantation embryo development rate were found to be highest in cultures where FSH support was implemented during the preantral stage. CONCLUSION: Exposure to FSH before formation of the antral-like cavity had a positive effect on follicle survival and oocyte robustness.

Animals↗
PubMed2004

Diurnal changes in FSH-regulatory peptides and their relationship to gonadotrophins in pubertal girls.

BACKGROUND: FSH-regulatory peptides participate with GnRH and sex steroids to regulate serum FSH concentrations. We hypothesized that day/night variations in FSH serum concentrations would be associated with diurnal variation in FSH-regulatory peptides. METHODS: Blood was obtained every 15 min for 24 h beginning at 08:00 h in eight girls [seven with variations in growth or puberty and one with idiopathic hypogonadotrophic hypogonadism (IHH)] and for 12 h beginning at 20:00 h in 12 additional girls with variant puberty, eight with gonadal dysgenesis or ovarian failure (GD/OF) and one with IHH. Samples across 3 h blocks were pooled for determination of LH, FSH, activin-A, inhibin-B and follistatin 288. RESULTS: LH and FSH concentrations increased from 23:00 to 08:00 h with respect to daytime concentrations in pubertal girls (P<0.005) but only LH increased (P=0.002) in girls with GD/OF. In pubertal girls, inhibin-B declined during the day (P=0.019), reaching a nadir between 17:00 and 22:45 h just prior to the night-time increase in FSH. Follistatin concentrations exhibited diurnal variation (P=0.028), with the greatest concentrations occurring between 05:00 and 11:00 h. Activin-A concentrations declined coincident with the night-time increase in FSH in pubertal girls (P<0.0001) but not in girls with GD/OF. CONCLUSIONS: The directionality of changes in FSH-regulatory proteins supports the notion that FSH-regulatory peptides may contribute to the night-time augmentation of circulating FSH during puberty in girls.

Activins↗
PubMed2001

Gonadotrophin receptor expression on human granulosa cells of low and normal responders to FSH.

The aim of this study was to determine if follicle stimulating hormone receptor and luteinizing hormone receptor (FSH-R and LH-R) expression is altered on granulosa cells (GC) of women with low oestradiol responses to FSH. Cells were obtained from mature follicles (>17 mm) following controlled ovarian stimulation. For comparison, chinese hamster ovary (CHO) cells transfected with FSH-R or LH-R were also assessed. FSH-R and LH-R expression were detected by flow cytometry. Receptors were labelled with FSH-R antibodies, or with excess FSH or human chorionic gonadotrophin (HCG) and anti-FSH or HCG antibodies, and compared to multiple controls. Receptor expression on GCs was more heterogeneous than on CHO cells. Gonadotrophin receptor levels on GCs were not correlated with the number of FSH ampoules administered or peak oestradiol response. Low and normal response groups were defined using a ratio of peak oestradiol/number of FSH ampoules. FSH receptor expression was not different on GCs from low and normal responders. However, LH-R expression was higher on GCs of low responders compared to those of normal responders (P = 0.04 ) suggesting a trend to more advanced luteinization. Access of hormone to follicles was not reduced in low responders. Thus, differences in gonadotrophin receptor expression, hormone binding, and access of hormones to follicles do not appear to account for low oestradiol responses to FSH.

Adult↗
PubMed1993

Changes in immunoreactive FSH and inhibin in developing chicken embryos and the effects of estradiol and the aromatase inhibitor R76713.

The interrelationship between immunoreactive inhibin and FSH was measured in chicken embryos from Day 8 to Day 20 of the incubation period. Plasma inhibin was measured by a heterologous RIA and FSH by a recently developed homologous RIA. Male and female inhibin plasma concentrations demonstrated a similar time course: a sharp increase with a peak on Day 13 was followed by a drop towards Day 18, after which inhibin levels stabilized. In male embryos, a similar time course was observed for the FSH concentrations. In sharp contrast, the FSH concentrations in the female embryos remained low and unchanged throughout the incubation period. Accordingly, sex differences were large for FSH and rather small for inhibin, and were noted from Day 10 and Day 12 on, respectively. No obvious inverse relationship was observed between inhibin and FSH. In male embryos, estradiol administration resulted in a dose-related decrease in FSH, accompanied by a less pronounced decrease in inhibin. Treatment with an aromatase inhibitor (R76713) increased FSH in female embryos and inhibin in both sexes. Generally, the experimentally induced changes in FSH were accompanied by comparatively small changes in inhibin. In conclusion, these observations suggest 1) that estradiol is an important inhibitor of pituitary FSH secretion in the chicken embryo, 2) that inhibin is not likely to play a major role in the feedback regulation of the hypothalamo-pituitary-gonadal axis, and 3) that an important fraction of the measured inhibin immunoactivity escapes the control of FSH. In view of the present data, the hypothesis is advanced that the gonads are not the major source of circulating immunoreactive inhibin in the chicken embryo.

Animals↗
PubMed1984

Discordant serum alpha-subunit and FSH concentrations in a woman with a pituitary tumour.

We have studied a women who presented at the age of 51 with a large FSH and alpha-subunit producing pituitary adenoma. Following insertion of ventriculo-peritoneal shunts and external pituitary irradiation there was no change in the elevated serum concentrations of FSH, and alpha-subunit over a four year period although she developed both ACTH and TSH deficiency. Various drugs, however, did alter the FSH and alpha-subunit concentrations and these changes suggest possible mechanisms controlling FSH secretion. Ethinyloestradiol 0.03 mg daily for three weeks suppressed serum FSH to 77% of the basal level (240 +/- 35 i.u./l to 184 +/- 20 i.u./l) but alpha-subunit rose to 130% of basal level (281 +/- 50 ng/ml to 366 +/- 40 ng/ml). On ethinyloestradiol 0.1 mg daily, FSH suppressed to 17% of basal (40 +/- 11 i.u./l) with no change in alpha-subunit concentration, while on 0.2 mg daily suppression of FSH was similar but alpha-subunit fell to 59% of basal (190 +/- 28 ng/ml). Dexamethasone, 3 mg daily for one week reduced FSH to 53% of the initial concentration and alpha-subunit to 74% while bromocriptine 7.5 mg daily for three months, reduced FSH to 39% and alpha-subunit to 66% of basal. Neither thyroxine, 0.2 mg daily for four weeks, nor an LHRH analogue, (Buserelin, Hoechst) 200 micrograms, three times daily for three months elicited any effect. Chromatography on Sephadex G100 showed that serum FSH and alpha-subunit both had Kav values somewhat lower than those of their standard counterparts (FSH, 0.20 vs 0.25; alpha-subunit 0.35 vs 0.45).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma, Chromophobe↗
PubMed1993

Efficacy of low dose purified FSH in ovulation induction following pituitary desensitization in polycystic ovarian syndrome.

OBJECTIVES: We evaluated the efficacy of ovulation induction using purified FSH in either low dose or conventional dosage in patients with polycystic ovarian syndrome. We assessed whether gonadotrophin measurement by radioimmunoassay or immunoradiometric assay is a better indicator of whether pituitary desensitization with a GnRH agonist (Zoladex) has occurred. DESIGN: Two different protocols were used. Pituitary desensitization was carried out with a GnRH agonist (Zoladex, ICI Pharmaceuticals UK). The patients were then randomized into one of two treatment groups. Conventional dose protocol: Patients commenced with a daily FSH (Metrodin, Serono Laboratories Ltd, UK) dose of 75 units for at least 7 days. The FSH dose was then increased, if necessary, based on ultrasound scans and plasma oestradiol (E2) levels in 75-unit increments. Low dose protocol: The same protocol was used except that the starting dose of FSH was 37.5 units daily with increments of 37.5 units. RESULTS: Low dose protocol (six patients, six cycles). There was a high incidence of multiple follicular development (10.3 +/- 5.6 (+/- SD) follicles, 5.0 +/- 3.8 follicles > 14 mm in diameter). Three cycles resulted in ovulation, one was anovulatory and two patients underwent gamete intrafallopian transfer due to multiple follicular development. Conventional dose protocol (seven patients, eight cycles). Again there was multiple follicular development (10.1 +/- 8.6 follicles, 2.0 +/- 2.3 > 14 mm). Three cycles were ovulatory, one anovulatory, three abandoned due to multiple follicular development and one underwent gamete intrafallopian transfer with the development of severe hyperstimulation necessitating steroid therapy. There was no difference between the two protocols in the number of days of FSH administration (low dose protocol 26 +/- 6.5, conventional dose protocol 23 +/- 8.1 days), the total number of units of FSH given per patient was 2844 +/- 1816 vs 2635 +/- 1726. The peak E2 level (pmol/l) during FSH treatment was 3193 +/- 662 vs 2389 +/- 3099 and the rate of increase in the FSH dose in ampoules of Metrodin per day was 0.058 +/- 0.03 vs 0.057 +/- 0.03. All patients were 'downregulated' (E2 < 70 pmol/l) prior to ovulation induction. However, gonadotrophin levels (IU/l) were 4.3 +/- 1.5 (LH) and 2.8 +/- 1.2 (FSH) by radioimmunoassay and LH was unchanged throughout FSH treatment whereas LH measured by immunoradiometric assay was < 1.0 IU/l prior to ovulation induction and remained so throughout. The mean LH radioimmunoassay to immunoradiometric assay ratio was 6.2 +/- 2.1. CONCLUSIONS: We conclude that regardless of the starting dose the use of pure FSH in patients with polycystic ovarian syndrome whose LH has been completely down regulated may be associated with multiple follicular development and a poor outcome. LH measured by radioimmunoassay is not a good indicator of whether pituitary densensitization has occurred but LH measured by immunoradiometric assay appears to be. These results strongly suggest that a basic minimum amount of LH is necessary for normal ovulatory development.

Adult↗
PubMed1994

Serum FSH and testicular morphology in male infertility.

OBJECTIVE: In patients with azoospermia serum FSH helps to differentiate between obstruction or spermatogenetic dysfunction as the possible cause of this condition. The role of FSH in the diagnosis of infertile men with oligoasthenoteratozoospermia is less clearly defined. In order to evaluate the diagnostic significance of serum FSH in the management of male infertility, serum FSH levels were related to testicular morphology from bilateral biopsies of infertile men. DESIGN AND PATIENTS: Testicular biopsies were obtained from 213 infertile men and evaluated in semi-thin sections. Biopsies were performed either in order to distinguish between obstructive and non-obstructive azoospermia or because of subnormal semen variables when history, clinical investigation and hormone levels failed to explain infertility. Serum FSH was measured by fluoroimmunoassay. RESULTS: Patients were divided into five groups on the basis of morphological criteria. The mean serum FSH value of patients with obstructive azoospermia and normal histology (group 1, n = 14) was normal (3.0 (2.2-4.1) IU/l) (mean (95% confidence limits)). Serum levels of FSH in non-obstructive oligo or azoospermia were as follows: group 2: mixed atrophy of tubular tissue without focal Sertoli cell only syndrome (SCO) (n = 104) (4.5 (4.0-5.1) IU/l), group 3: mixed atrophy with unilateral focal Sertoli cell only (n = 39) (7.4 (6.1-9.0) IU/l), group 4: mixed atrophy with bilateral focal SCO (n = 36) (10.7 (8.7-13.0) IU/l). Group 5: bilateral or unilateral total Sertoli cell only (n = 20) (16.0 (12.1-20.9) IU/l). Mean serum FSH levels were significantly different between all groups (P < 0.05). CONCLUSIONS: Elevation of serum FSH correlates with the appearance of Sertoli cell only tubules. Elevated FSH serum levels make testicular biopsies superfluous for diagnostic purposes, but normal FSH does not exclude severe derangement of spermatogenesis in individual cases.

Adult↗
PubMed1983

Porcine granulosa cell desensitization: prolonged FSH-responsive cAMP production in vitro.

Granulosa cells from small (1-2 mm) follicles of porcine ovaries produced cAMP in response to follicle-stimulating hormone (FSH); they produced little cAMP in response to human chorionic gonadotropin (hCG) or to cholera toxin. Production, estimated by quantification of total cAMP (medium + cells) by radioimmunoassay, appeared to be episodic in the absence or presence of the phosphodiesterase inhibitor 1-methyl-3-isobutylxanthine (MIX) and continued for at least 20 h. Results of dual incubation experiments with thorough washing of cells between incubations indicated that cells remained responsive to FSH, to hCG, and to cholera toxin after prior exposure to homologous stimulator. Preincubation of cells for 3 h in the absence of stimulator enhanced FSH responsiveness. In experiments with heterologous stimulators in two incubations, first, preincubation with FSH enhanced subsequent hCG and cholera toxin responsiveness; and second, preincubation with hCG or cholera toxin did not affect FSH responsiveness. Desensitization of FSH-activated adenylate cyclase was never greater than 35%; the degree of attenuation was dependent on FSH concentration and duration of exposure to FSH. Cells perifused with medium containing MIX and a maximally effective concentration of FSH for 5 h released cAMP continuously. In summary, the results indicated that porcine granulosa cells do not become unresponsive to FSH after prolonged exposure to FSH in vitro.

1-Methyl-3-isobutylxanthine↗
PubMed1985

FSH- and LH-releasing activity in the hypothalamus of female hamsters during proestrus and estrus: effects of arcuate nucleus lesions.

An in vitro bioassay was used to characterize the pattern of follicle-stimulating hormone (FSH)- and luteinizing hormone (LH)-releasing activities in the anterior (AH) and medial basal hypothalamus (MBH) during proestrus (P) and estrus (E) in the hamster. Regularly cycling hamsters were decapitated at 12.00, 16.00, 20.00 and 23.00 h of P and 02.00, 05.00, 08.00, 11.00, 14.00 and 17.00 h of E and sera assayed for FSH and LH. Neutralized extracts of the AH and MBH were incubated with a hemipituitary (HP), which was obtained from estrogen- and progesterone-primed ovariectomized rats. The incubation media were assayed for FSH and LH and the results expressed as nanograms of gonadotropin released per milligram HP. There was a surge of serum FSH and LH at 16.00 h of P and a surge of serum FSH only on E. LH-releasing activity in the AH and MBH declined late on P. This activity in the MBH increased by 08.00 h of E. FSH-releasing activity declined markedly in the MBH early on E when serum levels of FSH, but not LH, were rising. Conversely, low serum levels of FSH and high FSH releasing activity were found in the AH and MBH of animals with a chemically induced lesion of the arcuate nucleus. These data suggest that an FSH-releasing hormone may play an important role in the neuroendocrine control of FSH release.

Animals↗
PubMed1975

Induction of ovulation by LH and FSH in the presence of antigonadotrophic sera.

Surges of both LH and FSH are secreted on the day of proestrus in the rat; both surges are blocked by pentobarbital (PB), WHICH ALSO BLOCKS OVULATION. The purposes of the present study were (a) to see if antisera to ovine LH or FSH would prevent ovulation from endogenously secreted rat hormones; (b) to see if exogenous ovine LH or FSH alone can cause ovulation in the presence of antiserum to ovine LH or FSH, when endogenous hormone secretion is suppressed by PB. Antisera were assessed for anti-OAAD or anti-hCG augmentation activity against ovine and/or rat pituitary hormones. (a) With respect to tests against endogenously secreted hormones, antisera to LH block ovulation, but antisera to FSH do not, regardless of their potency against exogenous hormones. (b) Antisera to either ovine LH or FSH can prevent ovulation to either exogenous ovine hormone, in relation to their ability to block LH on OAAD bioassay, but not in relation to their ability to block FSH on the hCG augmentation test. However, one antiserum to FSH, which had very low anti-OAAD activity,was able to prevent ovine FSH, but not ovine LH, from causing ovulation, suggesting that not all of the ability of exogenous FSH to cause ovulation is related to intrinsic or contaminating OAAD activity. These data suggest that LH (as defined by OAAD) is the obligatory ovulating hormone in the rat. Additional data on uteirine intralumenal water in the presence of PB blockade indicate that LH, but not FSH, can induce some estrogen secretion, but that either hormone may cause some progesterone secretion.

Animals↗
PubMed1992

Regulation of FSH beta messenger ribonucleic acid levels in the rat by endogenous inhibin.

This study investigated the role of endogenous inhibin in regulating FSH beta mRNA levels subsequent to the gonadotropin surge in the immature, estradiol (E2)-treated female rat. Rats which undergo FSH surges on day 29 have low to undetectable levels of FSH beta mRNA at 0900 h on day 30, whereas those treated simultaneously with E2 and progesterone (P) implants to block these surges have considerably higher levels of FSH beta mRNA. In view of the profound inhibitory effect of inhibin on FSH beta mRNA, we examined the possibility that increased inhibin secretion is responsible for the decline in FSH beta mRNA levels on the morning after the FSH surge by immunoneutralization of endogenous inhibin. Twenty-eight day-old rats which received E2 and blank (B1) or P implants were injected iv with 0.4 ml of a potent anti-rat inhibin serum (anti I alpha, prepared in sheep against rat inhibin alpha (1-26)-Tyr27 coupled to human alpha-globulins) or normal sheep serum at 1700 to 1830 h on day 29 and were killed at 0900 h on day 30. Animals which received the inhibin antiserum showed significantly (P less than 0.001) elevated serum FSH levels (22.9 +/- 1.9 ng/ml [E2 + B1] and 17.1 +/- 0.6 ng/ml [E2 + P]) compared to those which received normal serum (4.4 +/- 0.1 [E2 + B1] and 4.2 +/- 0.1 [E2 + P]). Serum LH was undetectable (less than 0.6 ng/ml) in all groups. Free glycoprotein alpha-subunit was also increased (P less than 0.001) by antiserum to inhibin in E2 + B1-treated rats but was significantly suppressed by P after injection of either normal serum or anti I alpha. Total pituitary RNA was extracted and hybridized to cDNA probes for rat FSH beta, LH beta, and the common alpha-subunit by Northern blot analysis; RNA levels were normalized with beta-actin or cyclophilin probes. As expected, in rats which received normal serum, FSH beta mRNA levels were about 4-fold higher after treatment with E2 + P implants than after treatment with E2 + B1 implants. However, injection with anti-inhibin serum resulted in a striking elevation of FSH beta mRNA levels: 13-fold in animals treated with E2 + B1 implants and 5-fold in animals treated with E2 + P implants. There were no significant differences in levels of LH beta or alpha-subunit mRNAs between rats which received anti-inhibin or normal serum although there was a 30-40% decrease in alpha mRNA after P treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2001

Anti-Müllerian hormone attenuates the effects of FSH on follicle development in the mouse ovary.

Although ovarian follicle growth is under the influence of many growth factors and hormones of which FSH remains one of the most prominent regulators. Therefore, factors affecting the sensitivity of ovarian follicles to FSH are also important for follicle growth. The aim of the present study was to investigate whether anti-Müllerian hormone (AMH) has an inhibitory effect on follicle growth by decreasing the sensitivity of ovarian follicles to FSH. Furthermore, the combined action of AMH and FSH on ovarian follicle development was examined. Three different experiments were performed. Using an in vitro follicle culture system it was shown that FSH-stimulated preantral follicle growth is attenuated in the presence of AMH. This observation was confirmed by an in vivo experiment showing that in immature AMH-deficient females, more follicles start to grow under the influence of exogenous FSH than in their wild-type littermates. In a third experiment, examination of the follicle population of 4-month-old wild-type, FSH beta-, AMH-, and AMH-/FSH beta-deficient females revealed that loss of FSH expression has no impact on the number of primordial and preantral follicles, but the loss of inhibitory action of AMH on the recruitment of primordial follicles in AMH-deficient mice is increased in the absence of FSH. In conclusion, these studies show that AMH inhibits FSH-stimulated follicle growth in the mouse, suggesting that AMH is one of the factors determining the sensitivity of ovarian follicles for FSH and that AMH is a dominant regulator of early follicle growth.

Animals↗
PubMed1998

In situ amplification of the cytochrome P-450 cholesterol side-chain cleavage enzyme mRNA in single porcine granulosa cells by IGF-1 and FSH acting alone or in concert.

To investigate the cellular mechanisms and cell-cell heterogeneity of the actions of insulin-like growth factor-1 (IGF-1) and follicle-stimulating hormone (FSH) exerted alone and in combination on ovarian cholesterol side-chain cleavage gene expression (P450scc mRNA) in (pig) granulosa cells, we implemented semiquantitative in situ molecular hybridization at the single target-cell level. To this end, a 1-kb cDNA specific to the catalytic region of porcine p450scc gene was subcloned into pGEM-3 and directionally transcribed in vitro in the presence of 35S-dUTP to yield radiolabeled antisense (and sense, negative control) cRNA hybridization probes. Swine granulosa cells harvested nonenzymatically from immature (1-5 mm) Graafian follicles were anchored on eight-chamber multiwell slides and treated with control solvent, human recombinant IGF-1 (10nM), ovine FSH (10nM), or both hormones, for 48 h to stimulate progestin biosynthesis maximally. After appropriate cellular permeabilization, cRNA hybridization, and solvent washes, granulosa cells were exposed to Kodak NTB-2 emulsion for 6 wk. Semiquantitative automated image analysis software (NIH IMAGE 1.5) was used to evaluate the number of silver grains deposited/20,000 square pixels. Specificity controls included labeled sense riboprobe, pretreatment with RNase, and 100-fold molar excess unlabeled cRNA. Grain counts and their distributions were examined by ANOVA and the Wilcoxon nonparametric test. The mean number of silver grains deposited per granulosa cell increased over control (reflecting specific P450scc mRNA expression) in granulosa cells pretreated with IGF-1, FSH, or IGF-1 + FSH (p < 0.05 by ANOVA). The rank order of abundance of expression of P450scc mRNA (grains/ovarian cell) was (IGF-1 + FSH) > FSH > IGF-1 > control treatment. Distributional analysis showed that each treatment introduced skewed distributions toward granulosa cells expressing more P450scc per cell than controls (p < 0.01). The median grain count of granulosa cells treated with FSH was significantly increased over that of IGF-1 treatment (p < 0.05). Treatment with both IGF-1 and FSH further shifted the grain count distribution per cell to favor granulosa cells expressing more P450scc mRNA compared to IGF-1 or FSH treatment alone (p < 0.05). Accordingly, a demonstrable mechanism of IGF-1 and FSH's regulation of specific P450scc gene expression at the single granulosa cell level is amplification in the number of target ovarian cells expressing this enzymatically rate-determining gene transcript. Interestingly, the induction of P450scc mRNA is not sufficient to explain fully the synergistic increases in progesterone accumulation driven by combined treatment with IGF-1 and FSH, thus suggesting that other steroidogenic control points are also targets of IGF-1/FSH action.

Animals↗
PubMed1980

Measurement of rat serum FSH by radioreceptor assay and comparison with radioimmunoassay.

Follicle stimulating hormone (FSH) in rat serum is successfully measured by a radioreceptor assay system employing PMS-treated immature rat ovary. The non-specific inhibitory effect of serum was partially overcome by the addition of merthiolate to every component, while the residual effect was compensated for by using FSH-free serum which was prepared by passing the pooled female diestrous rat sera through an immunoadsorbent column packed with anti-ovine FSH-coupled Sepharose 4B. The assay system consisted of 100 microliter of Tris-MgCl2-BSA or standard, 100 microliter of FSH-free serum or sample, 100 microliter of the receptor preparation and 100 microliter of 125I-FSH. The incubation was carried out for 4 hr at 37 degrees C and 500 microliter of cold Tris-MgCl2-BSA was used for the termination. Serum FSH could be measured within a range of 0.125-16 ng NIAMDD rat FSH I-3/tube. The mean within-assay coefficient of variation was 10.5%. The mean between-assay coefficient of variation was 11.0%. The assay values obtained by RRA showed a good correlation to those by RIA under the same physiological states of the animals. The ratio of the assay values, RRA/RIA, was found to change according to the sex and the physiological states, e.g. around 1.3 in normal males and 1.7 in orchiectomized animals and 2.21 in female rats. Serum FSH levels in female rats obtained by RRA and RIA changed almost in parallel until 20 : 00 (hr) of proestrous day, but after the first surge of serum FSH they were not parallel. These facts seem to indicate possible changes in the affinity of FSH with its receptor according to the state of animals and lead to the problem of the heterogeneity of FSH.

Animals↗
PubMed1997

The activity of 17alpha-hydroxylase/C17-C20 lyase in the ovaries of immature hypophysectomized rats treated with recombinant FSH combined with various doses of human chorionic gonadotropin.

The activity of 17alpha-hydroxylase/C17-C20 lyase (17alpha-hydroxylase) in the ovaries and steroid hormone levels in the plasma were studied in immature hypophysectomized rats (IH-rats) treated with human recombinant follicle-stimulating hormone (rec-FSH) alone or combined with various doses of human chorionic gonadotropin (hCG). Eleven days after hypophysectomy, rats were given rec-FSH alone (total dose, 40 IU), or combined with various doses (0.1 to 10 IU in total) of hCG, twice daily for 4 days. Plasma levels of progesterone, testosterone and estradiol, and ovarian 17alpha-hydroxylase activity were measured 18 h after the last injection. Histology showed that the ovaries treated with rec-FSH alone had large antral follicles, the theca interna cells of which were small in size compared with those treated with rec-FSH combined with hCG. The activity of 17alpha-hydroxylase in the ovaries of IH-rats treated with rec-FSH alone was lower than that in the control IH-rats. It was markedly increased by treatment with rec-FSH combined with 1 or 10 IU hCG. Immunohistochemistry revealed that 17alpha-hydroxylase was localized only in the oocyte in the ovaries of control IH-rats and those treated with rec-FSH alone. When the IH-rats were treated with rec-FSH plus hCG, the number of immunopositive theca interna cells and interstitial cells, and their immunointensity were increased in an hCG dose-dependent manner. The plasma estradiol levels in the IH-rats treated with rec-FSH alone were low, but significantly higher than those in the control IH-rats, and estradiol levels were noticeably elevated in IH-rats treated with rec-FSH plus hCG. These results suggest that a synergism between hCG (LH) and FSH is essential for follicular development and steroidogenesis in the ovaries, implying paracrine effects among granulosa cells, theca cells and probably oocytes. The functional significance of 17alpha-hydroxylase in the oocytes is discussed in relation to estradiol production.

Animals↗
PubMed2005

FSH secretion predominates in vivo and in vitro in patients with non-functioning pituitary adenomas.

OBJECTIVE: Non-functioning pituitary adenomas (NFPAs) are characterised by the lack of symptoms of hormone hypersecretory syndromes but in vitro studies have demonstrated that tumour cells may stain for gonadotrophins and/or their alpha- or beta-subunits. In this study, we aimed to examine the pattern of secretion of LH and FSH from a series of pituitary adenomas cultured in vitro and where data were available to relate the results to pre-operative serum gonadotrophin levels. METHODS: The in vitro secretion of LH and FSH was measured from 46 cultured NFPAs and compared with pre-operative serum gonadotrophin levels in 38 patients. Peritumorous 'normal' pituitary cell cultures from 20 additional pituitary tumour patients were used for comparison with the NFPA group. RESULTS: A median pre-operative LH:FSH ratio of 0.33:1 was found in 38 patients with NFPAs. Preferential secretion of FSH was also documented from media of 46 NFPAs cultured in vitro with a median LH:FSH ratio of 0.32:1. A significant correlation (r = 0.43, P < 0.01) was observed between serum and media levels of FSH but not LH. Peritumorous 'normal' pituitary cells released LH and FSH in a reversed ratio (median LH:FSH ratio = 3.6:1, P < 0.01 compared with NFPAs). CONCLUSIONS: This study has evaluated pre-operative serum gonadotrophin levels and in vitro release of hormones in cultures of surgically removed tissue from patients with NFPAs. The data suggest preferential secretion of FSH occurs both in vitro and in vivo. By demonstrating that NFPAs cultured in vitro reflect the in vivo situation of preferential secretion of FSH, it may be possible in future to perform functional studies using this system to elucidate the cellular and molecular mechanisms involved in the development of an imbalance in gonadotroph cells preferentially overproducing FSH in NFPAs.

Adenoma↗
PubMed1985

FSH influences follicle viability, oestradiol biosynthesis and ovulation rate in Romney ewes.

Injection of steroid-free bovine follicular fluid (bFF; 2 X 5 ml s.c. 12 h apart) into anoestrous ewes lowered plasma FSH concentrations by 70% and after 24 h had significantly (P less than 0.01) reduced the number of non-atretic follicles (greater than or equal to 1 mm diam.) without influencing the total number of follicles (greater than 1 mm diam.) compared to untreated controls. Hourly injections of FSH (10 micrograms i.v. NIH-FSH-S12) for 24 h did not influence the number of non-atretic follicles but did negate the inhibitory effects of bFF on follicular viability. Hourly injections of FSH (50 micrograms i.v., NIH-FSH-S12) + bFF treatment for 24 h significantly increased the total number of non-atretic follicles, and particularly the number of medium to large non-atretic follicles (greater than 3 mm diam.) compared to the untreated controls (both P less than 0.01). The 10 micrograms FSH regimen (without bFF) significantly increased aromatase activity in granulosa cells from large (greater than or equal to 5 mm diam.; P less than 0.01) but not medium (3-4.5 mm diam.) or small (1-2.5 mm diam.) follicles compared to controls. The 10 micrograms FSH + bFF regimen had no effect on granulosa-cell aromatase activity compared to the controls. However, the 50 micrograms FSH plus bFF regimen increased the aromatase activity of granulosa cells from large, medium and small non-atretic follicles 2.6-, 8.3- and greater than or equal to 11-fold respectively compared to that in the control cells. Ewes (N = 11) that ovulated 2 follicles had significantly higher plasma FSH concentrations from 48 to 24 h and 24 to 0 h before the onset of a cloprostenol-induced follicular phase (both P less than 0.01) than in the ewes (N = 12) that subsequently ovulated one follicle. Hourly FSH treatment (1.6 micrograms i.v., NIAMDD-FSH-S15) for 24 h but not for any 6 h intervals between 48 and 24 h or 24 and 0 h before a cloprostenol-induced luteolysis also resulted in significant increases (P less than 0.05) in the number of ewes with 2 ovulations.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Season influences FSH concentration in ovariectomized Ile-de-France ewes.

Ile-de-France ewes were ovariectomized during anoestrus or the mid-luteal phase of an oestrous cycle (day of ovariectomy = Day 0). In a short-term study, FSH concentrations were measured in blood samples collected hourly the day before and on Days 1, 3, 7 and 15 after ovariectomy (10 ewes per group). FSH concentrations increased significantly from 6.1 to 16.5 ng/ml within 1 day of ovariectomy and increased further to 47.1 ng/ml by Day 15. Differences between seasons of ovariectomy were not significant. In a long-term study, FSH concentrations were measured in blood samples collected hourly on Days 7, 15, 30, 60, 90, 120, 150 and 180 after ovariectomy in anoestrus or the breeding season (10 ewes per group). Further samples were taken (5 ewes/group) at 240 and 365 days after ovariectomy. The pattern of change in FSH after ovariectomy differed between the two seasons and the interaction between season and sampling day was significant. For ewes ovariectomized during anoestrus, FSH concentrations increased to a maximum by Day 180 and remained high thereafter. In contrast FSH increased more slowly in ewes ovariectomized in the breeding season and differences between the groups were significant from Day 90 to Day 270. However, both groups had similar FSH concentrations at Day 365. These results show that FSH concentrations increase rapidly after ovariectomy. There are seasonal differences in FSH concentrations in the absence of ovarian feedback with increases in FSH concentration around the time of the onset of the breeding season. Once FSH concentrations had reached a maximum, major seasonal changes were no longer apparent.(ABSTRACT TRUNCATED AT 250 WORDS)

Anestrus↗