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PubMed1980

On the presence of FSH-beta subunit in the rat anterior pituitary and serum.

In order to elucidate the presence of free FSH-beta and LH-beta and their relation to the native hormones, immunoreactive FSH (IR-FSH), IR-LH, IR-FSH-beta, and IR-LH-beta subunits in the rat anterior pituitary and serum from 1200hr of proestrous day to 0600hr of estrous day were measured by radioimmunoassay. The amounts of IR-FSH-beta found were always more than those explained by the cross-reaction between FSH, and IR-FSH and IR-FSH-beta. On the other hand, IR-LH-beta was always less than the amount explained by the cross-reaction with LH, and changes in IR-LH and IR-LH-beta were parallel. There was also a difference between IR-FSH and IR-FSH-beta gel-filtration patterns in the rat anterior pituitary extracts. IR-FSH was eluted as a single peak, while IR-FSH-beta was found in three different regions. The first peak appeared near the void volume, the second corresponded to that of FSH, and the third was in the region of smaller molecules which was thought to be free FSH-beta. The first and the third peaks ofI R-FSH-beta changed characteristically during the estrous cycle. Radioiodinated FSH-beta, when incubated with the anterior pituitary extracts and applied to gel-filtration on Sephadex G-100, appeared also in three major peaks corresponding to those of IR-FSH-beta in the extracts. The first peak seemed to be aggregated or non-specifically bound FSH-beta and the second seemed to be FSH, while the third was thought to be free FSH-beta. These results indicated the presence of free FSH-beta in the rat anterior pituitary and serum, and raise a doubt about free LH-beta.

Animals↗
PubMed1998

Bioactive and immunoreactive FSH concentrations in ewe and ram lambs over the first year of life.

Several studies suggest that the concentration of immunoreactive (I) FSH measured in peripheral plasma by radioimmunoassay does not always reflect the level of bioactive (B) hormone capable of eliciting a biological response (e.g. oestradiol synthesis by Sertoli cells in vitro). The aim of this study was to measure both B-FSH and I-FSH concentrations in male and female sheep during the first year of life, and to relate this to pubertal development. The hypothesis being tested was that B-FSH is present in both male and female sheep during the prepubertal period and that discrete changes in B-FSH are associated with the onset of puberty. Eight ewe lambs and eight rams lambs were blood sampled fortnightly form 2 to 52 weeks of age. All samples were assayed for B-FSH content. Pubertal development was monitored in ewe lambs from behavioural oestrus and from plasma progesterone concentrations, and in ram lambs from penile and testicular development and from plasma testosterone concentrations. Mean I-FSH concentrations varied significantly with time after birth, in both females and males (P < 0.01). In contrast, B-FSH was found to vary with time in females only (P < 0.01). Around the expected time of puberty in ram lambs (i.e. at 30-40 weeks of age), and thereafter, I-FSH concentrations were undetectable (< 0.2 ng ml-1), whereas the B-FSH concentrations were measurable at concentrations up to twice the assay detection limit (0.8 ng ml-1) until 38 weeks of age. In ewe lambs, but not ram lambs, there was a significant linear relationship between B-FSH and I-FSH values (R = 0.595; P < 0.005). When standardised about the time of puberty, B-FSH (P < 0.05) but not I-FSH was significantly higher in ewe lambs that failed to reach puberty. No differences for either B-FSH or I-FSH between pubertal and non-pubertal ram lambs were noted. In summary, B-FSH was soften measurable in plasma throughout prepubertal development in sheep and the concentrations often differed from those of I-FSH, especially in ram lambs. However, there appeared to be no discrete change in B-FSH that could be directly related to specific pubertal events. It is concluded that although FSH may be a prerequisite for prepubertal testicular development and/or ovarian follicular growth, it is not a critical factor in determining whether puberty is attained during the first year of life in this seasonally breeding species.

Aging↗
PubMed2002

Acidic mix of FSH isoforms are better facilitators of ovarian follicular maturation and E2 production than the less acidic.

FSH is secreted as a mix of isoforms with varying biologic attributes. To determine the functional significance of FSH heterogeneity, an acidic (ovine pituitary FSH; C-FSH) and less acidic mix (C-FSH exposed to neuraminidase; N-FSH) were administered to prepubertal lambs. Production of GnRH- induced less acidic FSH was blocked with a competitive GnRH receptor antagonist, Nal-Glu. Beginning 24 h after Nal-Glu, lambs were injected with C-FSH or N-FSH and LH. Controls included untreated, GnRH-treated, and Nal-Glu-treated groups. Blood samples were obtained at 2-h intervals. Plasma FSH levels were similar before treatment and increased over time in the C-FSH but not the N-FSH group (P < 0.001). Three of the six GnRH-treated ewes exhibited an LH surge. Peak E2 concentrations in the GnRH-treated animals were achieved 30-36 h after initiation of treatment. Peak circulating E2 levels tended to be higher in the C-FSH than in the GnRH-treated group. Only two of six N-FSH-treated ewes had a serum E2 rise. The C-FSH ewes had more estrogenic follicles than the GnRH and N-FSH groups (P < 0.05). Our findings show that C-FSH clears more slowly than N-FSH, and C-FSH is a better facilitator of follicular development and maturation than N-FSH.

Acids↗
PubMed1993

Effect of chronic FSH administration on ovarian follicular development, ovulation rate and corpora lutea formation in sheep.

This study in ewes examined the effects on ovarian function of a pulsatile regimen of ovine FSH (NIADDK-oFSH-17) administered over a 24- to 28-day period beginning on day 1 of the oestrous cycle (day 0 = oestrus). The FSH (1.66 micrograms or 5.00 micrograms) was administered i.v. over a 1-min interval once every hour throughout the treatment period. In other ewes ovine LH (NIDDK-oLH-23) was administered (10 micrograms once every 2 h) for 24-28 days together with oFSH (1.66 micrograms/h). Compared with untreated controls (n = 19 ewes), FSH alone at both doses (n = 10 ewes/dose) as well as the FSH + LH treatment (n = 10) led to significant increases in the plasma concentrations of FSH (P < 0.01), ovarian weight (P < 0.05) and ovulation rate (P < 0.01) but there was no change in the mean weight of individual corpora lutea (CL). Exogenous FSH at the high but not the low dose alone or with LH stimulated a significant overall increase in plasma inhibin concentrations (P < 0.05). The geometric mean (and 95% confidence limits) ovulation rates in the high FSH (i.e. 5.00 micrograms/h), low FSH (i.e. 1.66 micrograms/h), low FSH + LH, and control treatment groups were 15.3 (9.3, 24.8), 3.7 (2.1, 6.0), 3.7 (2.5, 5.8) and 1.4 (1.2, 1.7) respectively. The FSH or FSH + LH treatments did not alter the total numbers of antral follicles (> or = 1 mm diameter). However, the high but not the low FSH or low FSH + LH treatment led to significant increases in the mean numbers of large follicles (i.e. > 4.5 mm diameter; P < 0.01) and a higher proportion of non-atretic antral follicles. Highly significant linear relationships were found between the mean plasma concentrations of FSH or inhibin and the ovulation rate (FSH: r = 0.74, P < 0.0001; inhibin: r = 0.93, P < 0.0001). Highly significant linear relationships were also found between the plasma concentrations of FSH or inhibin and the number of large follicles (i.e. > 4.5 mm diameter; FSH, r = 0.78, P < 0.0001; inhibin, r = 0.80, P < 0.0001) and between the plasma concentrations of inhibin and the number of granulosa cells in large follicles (r = 0.78, P < 0.0001). After the high FSH but not the low FSH treatment there were significant increases in both FSH- and LH-induced responsiveness in granulosa cells with respect to cyclic AMP synthesis in vitro.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1997

Surges of FSH during the follicular and early luteal phases of the estrous cycle in heifers.

Surges of FSH were characterized in each of 12 Holstein heifers using a computerized cycle detector program, and as mean changes averaged over all heifers. Blood samples were collected 6 times a day at 4-h intervals beginning at late diestrus. Concentrations of FSH were adjusted relative to the preovulatory LH peak (Hour 0) and profiled beginning 48 h before and ending 120 h after the LH peak. Peak concentrations of FSH and LH occurred synchronously in 11 of 12 (92%) heifers, and only a 4-h interval separated peak concentrations in the remaining heifer. The FSH surge that was synchronous with the LH surge was designated FSH Surge 1 and was used as a reference to designate other FSH surges. Surge -1 of FSH was detected in 58% of the heifers at mean Hour -21.2, and Surges 2, 3 and 4 were detected in 92%, 92% and 75% of the heifers, respectively, at mean Hours 25.1, 57.8 and 78.7. Mean peak levels and duration of FSH Surges-1, 2, 3 and 4 were significantly lower than for FSH Surge 1. Mean concentrations of FSH significantly increased and decreased before and after the LH peak, resulting from the synchrony between FSH Surge 1 and the LH surge in individual heifers. Additionally, there was a tendency (P < 0.08) for a second and third increase in mean FSH concentrations at Hours 24 and 60, which was attributed to FSH Surges 2 and 3 that occurred in individuals. Peak FSH concentrations of Surge 2 occurred (mean, Hour 25.1) within 8 h of maximal mean concentrations at Hour 24 in 91% of the heifers. Correspondingly, peak FSH concentrations of Surge 3 occurred (mean, Hour 57.8) within 8 h of maximal mean concentrations at Hour 60 in 64% of the heifers. Surges -1 and 4 of FSH occurred less frequently and at various times within and among heifers compared with Surges 1 to 3; therefore, they were not detected as mean increases in FSH concentrations but were masked as a result of concentrations being averaged over all heifers. In summary, FSH surges were detected in individual heifers before and after the combined FSH/LH surge. The interpeak intervals for FSH Surges 1 to 2 (25 h), 2 to 3 (33 h) and 3 to 4 (21 h) suggests a rhythmic nature to the surges.

Journal Article↗
PubMed1993

Serum FSH bioactivity and response to acute gonadotrophin releasing hormone (GnRH) agonist stimulation in patients with polycystic ovary syndrome (PCOS) as compared to control groups.

OBJECTIVE: We evaluated the biological activity of FSH in the serum of women with polycystic ovary syndrome before and after acute administration of a GnRH agonist as compared to control groups. DESIGN: FSH, oestradiol and androstenedione response to buserelin (100 micrograms s.c.) comparing seven polycystic ovary patients, six idiopathic hirsute women, 11 normal women in the follicular phase and nine normal men. MEASUREMENTS: Rat granulosa cell aromatase bioassay in the presence or absence of polyethyleneglycol (PEG) pretreated 2% serum. Serum biological FSH (B-FSH), immunological FSH (I-FSH) and B/I ratio at times 0, 1, 2, 3, 4, 8, 12 and 24 hours. Serum androstenedione and oestradiol at times 0 and 24 hours. RESULTS: Human gonadotrophin-free (oral contraceptive user and after FSH immunoabsorption) and PEG-pretreated serum increases the aromatase activity in response to increasing doses of purified FSH. The maximum enzymatic activity is however higher with 2% serum than with 4% serum. The amplitude of the B-FSH response to the GnRH agonist is markedly decreased in the polycystic group as compared to the group of normal women. There is also a small decrease in the I-FSH response in the polycystic women. When compared to that of normal women, the area under the curve in the polycystic ovary patients is reduced by 71% for B-FSH (P < 0.01) and by 23% for I-FSH (P < 0.05). The B-FSH and I-FSH responses in men are very small. After an initial decrease the B/I ratio returns to baseline level in normal women but remains low in the other groups. At time 24 hours, there is no significant change in the serum concentration of androstenedione but serum oestradiol, the baseline of which is significantly higher in the polycystic patients than in normal women, is also significantly higher at 24 hours (P < 0.05) in response to the pharmacological release of FSH. CONCLUSION: The gonadotrophin-free and PEG-pretreated human serum has an inherent stimulatory effect on the rat granulosa aromatase bioassay with a higher activity at 2% serum. Acute GnRH agonist stimulation reveals a deficiency in the FSH response in polycystic ovary patients. The greater deficit in B-FSH than in I-FSH would indicate a possible modification in the FSH isoforms in this syndrome. The meaning of this observation for the understanding of the physiopathology of the polycystic ovary syndrome remains to be evaluated.

Adolescent↗
PubMed2005

Calcium alginate microencapsulation of ovarian follicles impacts FSH delivery and follicle morphology.

BACKGROUND: We have previously shown that suspension culture prevents follicle flattening and maintains three-dimensional follicle architecture better than culture on flat plates. However, many of the follicles cultured in suspension do eventually rupture, as basement membrane integrity is lost and the three-dimensional structure of the follicle is altered. Therefore, the objective of this study is to support three-dimensional follicle architecture during in vitro growth of ovarian follicles through encapsulation in calcium alginate, while maintaining responsiveness to FSH stimulation. METHODS: Preantral follicles (150-160 micrometers in diameter) were isolated from the ovaries of juvenile rats and grown in culture tubes or encapsulated in calcium alginate and grown in culture tubes. Previous studies revealed that follicles maintained structural integrity but did not grow as well when encapsulated in calcium alginate. In these studies, we evaluated the effect of calcium alginate on FSH-stimulated follicle growth, survival, and morphology in suspension culture. Follicles were grown under 5 culture conditions: 1) not encapsulated; with FSH in the medium, 2) encapsulated in the absence of FSH, grown in medium without FSH, 3) encapsulated with calcium alginate containing FSH but grown in medium without FSH, 4) encapsulated without FSH but grown in medium containing FSH and 5) encapsulated with calcium alginate containing FSH and in medium containing FSH. To assess growth rates, follicles were cultured for 72 hours and analyzed for follicle size increase and DNA content. Survival analysis for encapsulated and unencapsulated follicles was performed by constructing a Kaplan Meier survival curve of daily observations of intact follicle survival. Three-dimensional architecture was assessed histologically and by analysis of the pattern of connexin 43 expression in the cultured follicles. RESULTS: In the absence of FSH, follicle diameter increased by only 6.4%. When FSH was included in the alginate bead alone or the media alone, the follicle diameter increased by 13.5% and 19.9% respectively. This was greater than follicles cultured in the absence of FSH (p < 0.05), but less than that of the FSH-treated unencapsulated follicles (p < 0.05). However, when follicles were cultured with FSH included in both the media and the bead, a 32.6% increase in follicle diameter was observed, statistically no different than the growth rate of the unencapsulated follicles grown with FSH. CONCLUSION: Microencapsulation supports three-dimensional follicle growth, but may limit access to hormones in the medium resulting in altered development compared to unencapsulated follicles. Inclusion of FSH in the alginate bead restores the follicle growth response to FSH, while also providing a scaffold of support for three-dimensional growth. The application of tissue engineering principles to the problems of follicle culture in vitro may provide advances applicable to fertility preservation in women and endangered species.

Alginates↗
PubMed2001

[Differences in human and rat FSH receptors promote activity as a result of the transcriptional factors: E2F1, E2F4 and E2F5 overexpression].

UNLABELLED: FSH-R expression in granulosa cells varies during the course of ovarian ontogenesis, as well as, during each menstrual cycle. Expression of follicle-stimulating hormone receptors (FSH-R) on Sertoli cells of the testis and ovarian granulosa cells depend on many paracrine and autocrine factors. The modulation of FSH-R synthesis is accomplished via a number of mechanisms including regulation of the promoter activity. Little is known about factors involved in control of FSH-R transcription in different species. The aim of the present study was to investigate differences in the regulation of human and rat FSH-R promoter activity by E2F transcriptional factors. MATERIAL AND METHODS: The 5'-flanking regions of human and rat FSH receptor gene subcloned in the pGL3 plasmid were transiently transfected into cultured CHO cells and rat granulosa cells. Rat granulosa cells were obtained by puncturing ovaries from DES primed immature Sprague-Dawley rats. Promoter activity was determined by measuring firefly luciferase luminescence of the cell lysate. Transfection efficiency was normalized by the renilla luciferase activity generated by co-transfected pRL-CMV vector. In order to determine the influence of E2F1, E2F4 and E2F5, on FSH-R promoter activity, cells were transfected either with promoter construct alone or with its mixture with selected expression vector. RESULTS: Rat FSH-R promoter construct (-1033/+6 bp) and human FSH-R promoter construct (-1485/-1 bp) were both active in transfected cells. Overexpression of E2F1 protein decreased both, human and rat wild type FSH-R promoter activity. Overexpression of E2F4 did not affect neither rat nor human FSH-R gene transcription. Expression vector for E2F5 increased both, human and rat, FSH-R promoter activity. Folds of increase were markedly higher in case of rat FSH-R construct transfection, comparing to human FSH-R promoter. CONCLUSIONS: Results suggest, that the E2F1 and E2F5 factors might play an opposite role in the regulation of FSH-R promoter activity. More pronounced stimulatory effect of E2F5 on the rat FSH-R can be explained by the presence of E2F site in the promoter. Since there is no E2F sensitive element in the human FSH-R promoter sequence, E2F1 and E2F5 can also indirectly influence FSH-R promoter activity.

Animals↗
PubMed2004

An elevated basal FSH reflects a quantitative rather than qualitative decline of the ovarian reserve.

BACKGROUND: Many cycling women with elevated basal FSH level have been discouraged from undergoing IVF treatment. This is because elevated basal FSH is associated with poorer assisted reproduction treatment outcome. It has been argued that high FSH reflects not only reduced ovarian reserve but also poor oocyte quality. The aim of this study is to assess the value of treating cycling women who have elevated basal FSH and to assess the reasons for the reduction in both pregnancy rate (PR) and live birth rate (LBR). METHODS: Between January 1997 and December 2001, 2057 patients underwent 3401 consecutive IVF/ICSI cycles in which the basal level of FSH (days 2-4) was determined at an earlier cycle. Analysis, however, was only performed for a single cycle per patient. All cases were divided into four cohorts according to FSH levels: group A, FSH <10 IU/ml; group B, 10.1-15 IU/ml; group C, 15.1-20 IU/ml; and group D, FSH >20 IU/ml. Each group was stratified further into subgroups according to age, < or =38 and >38 years. RESULTS: Both PR (A, 32.3%; B, 19.8%; C, 17.5%; and D, 3%) and LBR (A, 24.7%; B, 13.2%; C, 13.8%; and D, 3%) were significantly reduced in the higher FSH level groups. LBR was significantly higher in the younger subgroups (A, 32.2%; B, 21.8%; C, 20%; and D, 16.7%) as compared with the older subgroups (A, 12.1%; B, 8.3%; C, 10.5%; and D, 0%). Higher levels of FSH were significantly associated with more cycle cancellation, a larger amount of gonadotrophin required to achieve follicular maturity, and a lower number of eggs collected, embryos available and embryos transferred. In all cases, however, there was no significant correlation between FSH levels and fertilization rate or miscarriage rate. Younger cycling women with elevated FSH had significantly higher LBR compared with older women with normal FSH (21.2% versus 12.1%). Furthermore, the cumulative LBR after three cycles in these younger patients with elevated FSH levels was 49.3%. CONCLUSION: Although there is a reduction in both PR and LBR associated with higher levels of basal FSH, it is clear that in cycling women, high basal FSH is not a contraindication to IVF treatment, and a respectable PR and LBR can be achieved especially in young women. The reduction in PR and LBR is due to reduced reserve rather than poor oocyte quality. Clinics refusing to treat cycling women with elevated basal FSH levels may be denying these women a reasonable, albeit low, chance of achieving a birth with their own genetic material. Clinicians should use basal FSH levels as a guide to advise patients about their chances of achieving a live birth, not to exclude patients with a predicted lower success rate from a treatment programme.

Adult↗
PubMed1991

In vivo regulation of FSH synthesis by inhibin and activin.

The effect of a single sc injection of the gonadal peptide, recombinant human activin A (rhActivin A), on gonadotropin synthesis and secretion was examined in adult and immature male and female rats and the effect of recombinant human inhibin A (rhInhibin A) was examined in adult male rats. Pituitary FSH beta, LH beta and alpha messenger RNA (mRNA) levels were determined by blot hybridization. Trunk blood was collected to measure serum FSH levels. Treatment with rhInhibin A (100 micrograms/kg) resulted in a decrease in FSH beta mRNA to 2% of controls levels 6 h after injection. FSH beta mRNA levels started to rebound at 10 h, but were still significantly lower than vehicle-treated controls. Serum FSH levels were significantly reduced at 2 h and were reduced further at 6 and 10 h. There were no significant changes in alpha and LH beta mRNA levels. RhActivin A, at the highest dose (500 micrograms/kg), in immature male rats had only a modest effect (1.2- and 1.3-fold increase) on FSH beta mRNA levels and FSH secretion, respectively, at 2 h. No increase in FSH synthesis and FSH secretion was observed in adult male rats. In contrast, both immature and adult-ovariectomized E2 implanted females showed a robust response to rhActivin A. In immature females, 2 h after rhActivin A (100 and 500 micrograms/kg) administration, FSH beta mRNA levels were elevated 2.0- and 2.2-fold. At this time serum FSH was also elevated. At 6 and 10 h rhActivin A significantly reduced FSH beta mRNA levels from vehicle-treated controls. In contrast, FSH secretion was elevated at 6 h and returned to baseline at 10 h. Administration of rhActivin A (500 micrograms/kg) to adult, ovariectomized-E2 females resulted in a significant increase in FSH beta mRNA levels and FSH secretion at 2 and 6 h. There were no significant changes in alpha and LH beta mRNA levels in either males or females. Thus, these in vivo studies have shown that rhInhibin A can inhibit FSH beta mRNA levels and FSH secretion in the adult male rat. RhActivin A stimulates FSH synthesis and secretion in the immature and adult ovariectomized-E2 females, but has little or no effect in immature and adult males. Hence, there is a sexual dimorphic response to rhActivin A in vivo in the rat.

Activins↗
PubMed2000

Isoforms and half-life of FSH from sheep with different reproductive states.

The glycoprotein hormone FSH comes in many different isoforms. In humans and rats the charges of the FSH isoforms vary with reproductive state and these affect the half-life of FSH in plasma. In this study we examined the charge heterogeneity of FSH in pituitary extracts from sheep with different reproductive states. Also the half-life of clearance of pituitary FSH from the different reproductive states was determined in mice. Pituitaries were collected from: anoestrous, luteal phase, follicular phase, early-pregnant and late-pregnant ewes, ewe lambs, ram lambs, rams during the breeding and non-breeding seasons and wethers (5 per group). After extraction, FSH isoforms were fractionated by HPLC anion exchange chromatography. The volume at which half of the FSH had eluted from the ion exchange column was determined (HP(50)). It was found that FSH isoforms from ewes (HP(50)=96.7+/- 1.3 ml (s.e.m. )) eluted later (P<0.01) than those from rams (HP(50)=82.3+/-1.3 ml) indicating that FSH isoforms in the ewes were more acidic than those from rams. There was a seasonal difference in ewes, with ewes in anoestrus (HP(50)=101.6+/-2.6 ml) having more-acidic (P<0.01) FSH isoforms than the ewes during the oestrous cycle (HP(50)=95.3+/-0.7 ml). There was an effect of age, with the FSH isoforms from cycling ewes (HP(50)=95.3+/- 0.7 ml) being more acidic (P<0.01) than those from ewe lambs (HP(50)=88.3+/-1.9 ml). There was an effect of pregnancy, with late-pregnant ewes (HP(50)=107.3+/- 1.6 ml) having more-acidic FSH isoforms (P<0.05) than those from anoestrous ewes (HP(50)=101.6+/-2.6 ml) and there was an effect of castration with the breeding season rams (HP(50)=80.7+/-1.4 ml) having more-acidic (P<0.05) FSH isoforms than wethers (HP(50)=74.0+/-0.5 ml). The half-life of pituitary FSH from animals in the different reproductive states was found to be negatively correlated with HP(50) (r(2)=0.56, P<0.01). The FSH isoforms from wethers were the least acidic and had the longest half-lives. Collectively, these findings show that in sheep, age, sex and reproductive state are all factors which influence the forms of FSH that are extracted from the pituitary gland. Moreover, these results demonstrate that FSH from sheep with the most-acidic FSH isoforms have the shortest half-life in plasma.

Aging↗
PubMed1990

Immunocytochemical localization of the subunits of glycoprotein hormones (LH, FSH, and TSH) in the bullfrog pituitary gland using monoclonal antibodies and polyclonal antiserum.

Using beta and alpha subunits of bullfrog follitropin (FSH) III (pI 6.2), which were highly purified by HPLC, we generated three monoclonal antibodies (MCAs) to FSH beta subunit (FSH beta) and six to FSH alpha subunit (FSH alpha). They were produced by hybridomas derived from the myeloma X63.Ag8.653 and spleen lymphocytes from mice immunized with each subunit. Non-competitive binding tests revealed that one of the MCAs against FSH beta (BF3B25) bound strongly to intact FSH and its beta subunit, but not FSH alpha, lutropin (LH), LH alpha, and LH beta. The immunoblotting results also showed a similar immunological specificity for BF3B25. Cross-reactivity of bullfrog FSH against BF3B25 was 19.4%, when compared with FSH beta in the competitive inhibition assay system. On the other hand, noncompetitive binding tests and immunoblotting results showed that one of the MCAs against FSH alpha (BF3A20) bound strongly to intact LH and FSH and their alpha subunits, but not their beta subunits. The inhibition curves obtained using the alpha subunits of LH and FSH were similar. In the sexually mature bullfrog pituitary, immunoreactive FSH cells stained with MCA BF3B25 were distributed throughout the pars distalis, except for the rostral region, and were polygonal in shape, with well-developed cytoplasm. With respect to distribution and histological characteristics, the immunoreactive LH cells were very similar to the immunoreactive FSH cells when consecutive sections were stained with LH beta-specific MCA (BL4B11). However, immunoreactive TSH cells, revealed by anti-human TSH beta serum, formed clusters in the ventrocentral region of the pars distalis. In young adult pituitary, almost all of the gonadotrophs showed the coexistence of FSH and LH, but some gonadotrophs contained only FSH. The number of immunoreactive alpha-subunit cells stained by BF3A20 was always higher than the sum of the numbers of cells stained by the three beta-subunit-specific antibodies.

Animals↗
PubMed1983

Differential hypothalamic control of FSH secretion: a review.

There are many circumstances in which the release of FSH and LH is dissociated; however, many of these are now thought to be brought about by interactions of LH-releasing hormone (LHRH), which stimulates not only LH but also FSH release, and the gonadal peptide, inhibin, which acts at the pituitary to suppress FSH release selectively. There are also many examples which can only be explained by postulating separate hypothalamic control of FSH and LH release. For example, electrochemical stimulation of the medial preoptic area elicited only LH release, whereas stimulation further caudally elicited equivalent LH release but FSH release as well. Points of stimulation particularly in the dorsal anterior hypothalamic area (DAHA) evoked only FSH release. Furthermore, implantation of prostaglandin E2 in various hypothalamic loci in a region extending from the DAHA caudally and ventrally to the caudal median eminence (ME) selectively elicited FSH release. Lesions of the DAHA resulted in a decrease of plasma FSH but not LH in castrated male and female rats and also suppressed the post-castration rise in FSH in males. In ovariectomized estrogen-primed rats with DAHA lesions, injection of progesterone provoked a normal LH surge but a significantly depressed FSH surge. Anterior ME lesions in castrates lowered LH levels more than FSH levels. Extracts of the DAHA evoked greater FSH and LH release in vitro than could be accounted for by the content of LHRH in the extracts, but there was no preferential release of FSH. On the other hand, extracts of the organum vasculosum lamina terminalis (OVLT) evoked dramatically increased FSH release above that which could be accounted for by the content of LHRH. Lastly, posterior ME extracts had more FSH-releasing activity than could be accounted for by their content of LHRH. All these results suggest the existence of an FSH-releasing factor (FSHRF) and lead to the speculation that the cell bodies of FSHRF neurons are located in the DAHA, with axons projecting to the OVLT and to the posterior ME. In other experiments, attempts were made to purify rat and sheep hypothalamic extracts by gel filtration on Sephadex G-25 and to assay the FSH-releasing activity by both bio- and immunoassay. Using this approach, we obtained evidence for the early emergence of a bioactive FSHRF prior to the emergence of LHRH from the column. Although much more work remains to be done, the accumulated evidence strongly supports the concept of a distinct FSHRF.

Animals↗
PubMed2000

In vivo oocyte recovery and in vitro embryo production from bovine oocyte donors treated with progestagen, oestradiol and FSH.

The effect of treatment of donor cattle with progestagen and oestradiol or FSH on in vivo oocyte recovery and in vitro embryo production was studied. Forty-eight beefxFriesian cows formed eight replicates of six treatments in a 2 (no steroid versus steroid)x3 (none, single or multiple dose(s) of FSH) factorial design in which follicles were aspirated once weekly for 3 weeks. Oocytes were graded, washed, matured for 20-24h and then inseminated with frozen/thawed semen from a single sire followed by coculture on granulosa cell monolayers. Treatment with steroid had no significant effect on any follicular, oocyte or embryo production variate other than to reduce the number (P<0.05) and the diameter of large follicles>10mm (P<0.01) present at aspiration. FSH increased numbers of medium (6-10mm) and large follicles (P<0.01) and there was a corresponding decrease in the number of small follicles (2-5mm; P<0. 01). The total number of follicles at aspiration increased from 17. 7+/-1.60 for animals not treated with FSH to 23.6+/-1.97 following multiple dose treatment with FSH (P<0.05). Significantly, more follicles were aspirated following FSH treatment (no FSH 9.7+/-1.09, single dose FSH 13.6+/-1.30, multiple dose FSH 17.3+/-1.52; P<0.05) and numbers of oocytes recovered per cow per week increased (no FSH 4.1+/-0.76, single dose FSH 5.3+/-0.87, multiple dose FSH 5.9+/-0. 94) but the differences were not significant. Significantly, more good oocytes (Category 1) were recovered from animals treated with FSH (P<0.05). There was no overall significant effect of FSH on embryo production rate or the total number of transferable embryos produced but the number of transferable embryos was highest following administration of multiple doses of FSH. In conclusion, progestagen plus oestradiol 17beta treatment did not affect follicle, oocyte and embryo production of oocyte donors aspirated once per week. FSH treatment, however, significantly increased the number of follicles aspirated and Category 1 oocytes recovered. Multiple dose administration of FSH resulted in the production of the highest number of transferable embryos but this effect was not significant.

Animals↗
PubMed1994

Co-ordinate actions of FSH and insulin-like growth factor-I on LH receptor expression in rat granulosa cells.

The actions of FSH and Insulin-like growth factor-I (IGF-I) were studied in cultured rat ovarian granulosa cells. Cells became differentiated and expressed LH receptors when they were incubated for 72 h with 200 micrograms FSH/l (high FSH) but not 20 micrograms FSH/l (low FSH). Treatment with high but not low FSH increased the release of both immunoreactive and bioactive IGF-I into the medium. A combination of low FSH and IGF-I reproduced the effect of high FSH on LH receptor expression. We then examined the critical time when low FSH and IGF-I exerted their effects. In the presence of continuous low FSH, IGF-I was capable of inducing LH receptor expression even when added 24 h after the addition of low FSH. However, when IGF-I was added at 36 h, LH receptor expression measured at 72 h was greatly reduced. In contrast to the action of IGF-I, continuous exposure to low FSH was required for LH receptor expression, and IGF-I had no effect when FSH was not included for the entire 72 h of culture. DNA synthesis as assessed by both [3H]thymidine incorporation and nuclear bromodeoxyuridine labelling was moderate at the beginning of culture and markedly reduced at 24 h both in the presence and absence of either high FSH or low FSH plus IGF-I. In the presence of either high FSH or a combination of low FSH plus IGF-I, DNA synthesis remained decreased for up to 72 h whereas it began to increase in the absence of either high FSH or a combination of low FSH plus IGF-I.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1996

The significance of elevated early follicular-phase follicle stimulating hormone (FSH) levels: observations in unstimulated in vitro fertilization cycles.

OBJECTIVE: Our objective was to determine the effect of elevated early follicular-phase serum follicle stimulating hormone (FSH) levels on follicle growth and oocyte maturity in unstimulated in vitro fertilization (IVF) cycles. STUDY DESIGN: We compared cycles with elevated day 3 FSH levels (> 20 mIU/ml) to subsequent cycles in the same patients when day 3 FSH returned to normal and to cycles among women with normal day 3 FSH levels. PATIENTS: Seven cycles in seven patients had an elevated day 3 FSH (high-FSH group). These were compared to 11 subsequent cycles in which there was a return to a normal baseline FSH and to 13 cycles in 13 patients that entered the unstimulated protocol with a normal baseline day 3 FSH. RESULTS: The day of human chorionic gonadotropin (hCG) administration was similar in all groups as were the serum estradiol (E2) levels. Although the high-FSH group tended to have smaller maximum follicular diameters, the difference was not statistically significant. The highest FSH level on cycle day 3 in a completed cycle was 56.2 mIU/ml. The total number of oocytes aspirated and the number of embryos obtained was similar in all groups. Whereas there were no pregnancies in the high-FSH group, 2 of the subsequent 11 normal day 3 FSH cycles resulted in clinical pregnancies. Two of the 13 patients in the normal day 3 FSH values also achieved pregnancies. CONCLUSIONS: We conclude that cycle day 3 serum FSH levels as high as 56.2 mIU/ml may be associated with apparently normal follicular growth, oocyte fertilization, and embryo cleavage in unstimulated cycles. However, pregnancies are not observed. In addition, FSH levels vary widely from cycle to cycle and elevated levels in one cycle do not necessarily imply that pregnancy may not occur in a subsequent cycle when FSH levels return to normal.

Blastocyst↗
PubMed1998

Differential responses of granulosa cells from small and large follicles to follicle stimulating hormone (FSH) during the menstrual cycle and acyclicity: effects of tumour necrosis factor-alpha.

This study determined effects of follicle stimulating hormone (FSH) alone and in combination with tumour necrosis factor (TNF), on granulosa cells from small (5-10 mm diameter) and large (>10-25 mm) follicles during follicular and luteal phases of the cycle and during periods of acyclicity. Granulosa cells were collected from ovaries of premenopausal women undergoing oophorectomy. The cells were cultured with human FSH (2 ng/ml) and testosterone (1 microM) in the presence or absence of human TNF-alpha (20 ng/ml). Media were removed at 48 and 96 h after culture and progesterone, oestradiol and cAMP in media were measured by radioimmunoassays. FSH stimulated the accumulation of oestradiol from granulosa cells of small follicles during the follicular and luteal phases but not during acyclicity; and TNF reduced oestradiol accumulation in the presence of FSH. Interestingly, in granulosa cells from small follicles, progesterone and cAMP secretion increased in response to FSH and neither was affected by TNF. Thus, TNF specifically inhibited the conversion of testosterone to oestradiol in granulosa cells from small follicles. FSH stimulated oestradiol production by granulosa cells of large follicles obtained only during the follicular phase of the cycle and TNF inhibited the FSH-induced oestradiol secretion. Granulosa cells obtained from large follicles during the luteal phase and during acyclicity did not accumulate oestradiol in response to FSH. However, FSH increased progesterone and cAMP secretion by granulosa cells obtained from large follicles during the follicular and luteal phases. During the luteal phase alone, TNF in combination with FSH increased progesterone accumulation above that of FSH alone. FSH did not increase progesterone, oestradiol or cAMP secretion by granulosa cells obtained from large follicles during acyclicity. Thus, FSH increases progesterone, oestradiol and cAMP secretion by granulosa cells of small follicles during the follicular and luteal phases and TNF appears to inhibit FSH-induced oestradiol secretion specifically in those cells. In large follicles, FSH-stimulated granulosa cell secretion of oestradiol is limited to the follicular phase and this effect can be inhibited by TNF. In addition, when granulosa cells of large follicles do not increase oestradiol secretion in response to FSH, TNF stimulates progesterone secretion.

Adult↗
PubMed1990

Comparison of the pretranslational regulation of FSH synthesis by gonadal steroids in rats and mice.

There are significant differences between rats and mice in the gonadal regulation of several aspects of gonadotroph function. To investigate whether these extend to the pretranslational regulation of FSH synthesis by gonadal steroids, we have measured FSH-beta mRNA levels following gonadectomy and sex-steroid replacement and have related these to serum and pituitary FSH as a reflection of overall hormone synthesis. In ovariectomized rats, FSH-beta mRNA levels increased by 8 h, decreased, and then rose progressively over the next 28 days. A similar pattern of response was observed in orchidectomized rats. In mice, there were progressive increases in FSH-beta mRNA levels in both males and females following gonadectomy, without evidence of the early peaks observed in rats. In both species, the change in FSH-beta mRNA levels after gonadectomy was greater in females than in males. These changes in FSH-beta mRNA following gonadectomy were paralleled by changes in the serum FSH concentration. In ovariectomized female rats and mice, pituitary FSH stores increased by 8 h and 3 days respectively, whereas in male rats, pituitary FSH content did not rise until 10 days after orchidectomy. The most striking species difference was the marked and prolonged reduction of pituitary FSH after orchidectomy of mice. Treatment of rats and mice from the time of ovariectomy, with a dose of oestradiol that prevents increases in serum LH, only partially attenuated the rises in FSH-beta mRNA and serum FSH and did not prevent the increase in pituitary FSH content. Treatment of intact or orchidectomized rats with testosterone suppressed FSH-beta mRNA levels to 50% below intact control values without affecting pituitary FSH content.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗