Sequential step-up and step-down dose regimen: an alternative method for ovulation induction with follicle-stimulating hormone in polycystic ovarian syndrome

This study was designed to compare both the effectiveness and safety of two low-dose gonadotrophin regimens (step-up versus sequential step-up and step-down) for ovulation induction in polycystic ovarian syndrome (PCOS) patients. In all, 56 infertile clomiphene citrate-resistant PCOS patients were included in this prospective randomized study. A total of 38 cycles were conducted with a classic step-up protocol, whereas for 35 cycles the follicle-stimulating hormone (FSH) threshold dose was reduced by half when the leading follicle reached 14 mm in diameter (sequential protocol). Serum oestradiol, progesterone and luteinizing hormone concentrations and follicular growth rate were evaluated during the cycle. At the time of human chorionic gonadotrophin administration, cycles treated with sequential protocol exhibited significantly lower oestradiol concentrations [434 +/- 45 versus 593 +/- 67 pg/ml (mean +/- SEM)] and the number of medium-sized (14-15 mm) follicles was significantly reduced (0.3 +/- 0.1 versus 0.8 +/- 0.2) compared with cycles treated with the classic step-up protocol. Moreover, in these cycles serum luteal oestradiol concentrations were decreased significantly (350 +/- 77 versus 657 +/- 104 pg/ ml) compared with the classic step-up protocol. A sequential step-up and step-down protocol seems to be a safe and effective regimen for ovulation induction in PCOS patients. Decreasing the FSH dose following step-up follicular selection may be an alternative method to avoid multifollicular development.     

Luteinizing hormone response to gonadotrophin-releasing hormone in normal women undergoing ovulation induction with urinary or recombinant follicle stimulating hormone

Oestradiol enhances pituitary sensitivity to gonadotrophin-releasing hormone (GnRH) in normal women, while in women undergoing ovulation induction the putative factor gonadotrophin surge attenuating factor (GnSAF) attenuates the response of luteinizing hormone (LH) to GnRH. To study the relationships between oestradiol and GnSAF during ovulation induction, 15 normally ovulating women were investigated in an untreated spontaneous cycle (control, first cycle), in a cycle treated with daily i.m. injections of 225 IU urinary follicle-stimulating hormone (FSH) (Metrodin HP, uFSH cycle) and in a cycle treated with daily s.c. injections of 225 IU recombinant FSH (Gonal-F, rFSH cycle). Treatment with FSH started on cycle day 2. The women during the second and third cycle were allocated to the two treatments in an alternate way. One woman who became pregnant during the first treatment cycle (rFSH) was excluded from the study. In all cycles, an i.v. injection of 10 microg GnRH was given to the women (n = 14) daily from days 2-7 as well as from the day on which the leading follicle was 14 mm in diameter (day V) until mid-cycle (n = 7). The response of LH to GnRH at 30 min (deltaLH), representing pituitary sensitivity, was calculated. In the spontaneous (control) cycles, deltaLH values increased significantly only during the late follicular phase, i.e. from day V to mid-cycle, at which time they were correlated significantly with serum oestradiol values (r = 0.554, P < 0.01). Initially during the early follicular phase in the uFSH and the rFSH cycles, deltaLH values showed a significant decline which was not related to oestradiol (increased GnSAF bioactivity). Then, deltaLH values increased significantly on cycle day 7 and further on day v with no change thereafter up to mid-cycle. On these two days, deltaLH values were correlated significantly with serum oestradiol values (r = 0.587 and r = 0.652 respectively, P < 0.05). During the pre-ovulatory period, deltaLH values in the FSH cycles were significantly lower than in the spontaneous cycles. Significantly higher serum FSH values were achieved during treatment with uFSH than rFSH. However, serum values of oestradiol, immunoreactive inhibin, and deltaLH as well as the number of follicles > or = 12 mm in diameter did not differ significantly between the two FSH preparations. These results suggest that in women undergoing ovulation induction with FSH, oestradiol enhances pituitary sensitivity to GnRH, while GnSAF exerts antagonistic effects. The rFSH used in this study (Gonal-F) was at least as effective as the uFSH preparation (Metrodin-HP) in inducing multiple follicular maturation in normally cycling women.     

Abnormal twenty-four hour pattern of pulsatile luteinizing hormone secretion and the response to naloxone in women with hyperprolactinaemic amenorrhoea

OBJECTIVE: Hyperprolactinaemic amenorrhoea is associated with disturbances of pulsatile gonadotrophin secretion. The underlying mechanism remains unclear and the aim of this study was to investigate the 24-hour secretory pattern of gonadotrophins in women with hyperprolactinaemic amenorrhoea. The effect of opioid blockade using naloxone infusion on LH secretory pattern was also studied. DESIGN: The secretory patterns of LH, FSH, PRL and their responses to naloxone infusion were studied by serial blood samples collected at 10-minute intervals for 24 hours. On the following day, naloxone was infused at a dose of 1.6 mg per hour for 4 hours. PATIENTS: Eight women with hyperprolactinaemic amenorrhoea, two women hyperprolactinaemic but with normal ovarian cycles, and nine control subjects in the early follicular phase of menstrual cycle. MEASUREMENTS: Concentrations of LH, FSH and PRL were measured in plasma samples obtained at 10-minute intervals for 24 hours. In one woman, concentrations of urinary oestrone glucuronide were measured daily during treatment with pulsatile GnRH. RESULTS: The number of LH pulses per 24 hours was significantly fewer in women with hyperprolactinaemic amenorrhoea than in those with hyperprolactinaemia with normal cycles or control subjects (mean +/- SEM 4.5 +/- 2.4 vs 13.5 +/- 2.5 vs 17.3 +/- 0.8, P < 0.001). The magnitude of each episode of secretion was significantly higher in the hyperprolactinaemic amenorrhoeic women (P < 0.05) so the overall mean concentrations of LH throughout the 24-hour period was similar in the three groups (5.2 +/- 1.1, 4.8 +/- 0.8 and 5.2 +/- 0.4 U/l respectively). In women with hyperprolactinaemic amenorrhoea there was no significant change in the pattern of LH secretion during sleep in contrast to the control women in whom there was a slowing in the LH pulse frequency during the night. There was no significant change in the mean concentrations of LH, FSH and PRL during the naloxone infusion. There were also no significant changes in the LH pulse frequency in response to naloxone infusion when compared with an equivalent period of time in the previous 24 hours. In one hyperprolactinaemic amenorrhoeic woman, follicular development, ovulation and pregnancy were induced when gonadotrophin releasing hormone (GnRH) was infused in a pulsatile manner at a dose of 5 micrograms every 90 minutes. CONCLUSIONS: The suppression of normal ovarian cycles in women with hyperprolactinaemic amenorrhoea is due to a significant reduction in frequency of LH (GnRH) secretion which is not due to an increase in hypothalamic opioid activity. As normal ovarian cycles can occur or be induced by exogenous GnRH in hyperprolactinaemia, it is unlikely that a high level of prolactin by itself inhibits follicular development and ovulation.     

The follicle-stimulating hormone (FSH) threshold/window concept examined by different interventions with exogenous FSH during the follicular phase of the normal menstrual cycle: duration, rather than magnitude, of FSH increase affects follicle development

According to the threshold concept, FSH concentrations need to surpass a distinct level to stimulate ovarian follicle growth. The window concept stresses the significance of a limited duration of elevated FSH levels above the threshold for single dominant follicle selection. The aim of this study was to investigate effects on follicle growth of increased FSH levels, differing in duration and magnitude of elevation, during the follicular phase. Twenty-three normo-ovulatory (cycle length, 26-31 days), young (age, 20-31 yr) women volunteered for this study. In all subjects a series of daily transvaginal sonography scans of the ovaries and blood sampling [for FSH and estradiol (E2) determinations] were performed during two consecutive cycles. The first study cycle (control cycle) started 10 days after urinary assessment of the LH surge in the preceding cycle (DayLH) and was concluded on the day of ovulation assessed by transvaginal sonography scans. The second series of daily monitoring (intervention cycle) started 10 days after DayLH in the control cycle. After randomization, subjects received either 375 IU urinary FSH, s.c., as a single injection on Day(LH+14) (group A; n = 11) or 75 IU daily from Day(LH+19) until Day(LH+23) (group B; n = 12). In group A, FSH levels increased on the day after injection to a median concentration of 10.1 IU/L, which was 1.9 times higher (P < 0.01) than levels on matching days during the control cycle. Concentrations returned to basal levels 3 days after injection. In group B, a moderate elevation of FSH concentrations (15% increase; P < 0.05) was observed compared to levels during the control cycle. In group A, E2 concentrations increased (P = 0.03) 1 day after FSH injection and returned to baseline levels within 2 days. In group B, E2 levels started to increase after the first injection of FSH and remained significantly higher (P < 0.01) during the following 5 days compared to those on matching days in the control cycle. Compared to matching days in the control cycle an increased number of follicles 8-10 mm in size was found in group A (P < 0.01) during the period from Day(LH+14) until Day(LH+19), without an increase in follicles 10 mm or larger thereafter. In contrast, in group B, the numbers of both 8- to 10-mm and 10-mm or larger follicles were higher during the period from Day(LH+19) until Day(LH+24) in group B (P = 0.02 and P < 0.01, respectively). Results from the present study suggest that a brief, but distinct, elevation of FSH levels above the threshold in the early follicular phase does not affect dominant follicle development, although the number of small antral follicles did increase. In contrast, a moderate, but continued, elevation of FSH levels during the mid to late follicular phase (effectively preventing decremental FSH concentrations) does interfere with single dominant follicle selection and induces ongoing growth of multiple follicles. These findings substantiate the FSH window concept and support the idea of enhanced sensitivity of more mature follicles for stimulation by FSH. These results may provide the basis for further investigation regarding ovulation induction treatment regimens with reduced complication rates due to overstimulation.     

Resumption of follicular waves in beef cows is not associated with periparturient changes in follicle-stimulating hormone heterogeneity despite major changes in steroid and luteinizing hormone concentrations

To test the hypothesis that emergence of follicle waves postpartum is associated with a change in circulating FSH isoform distribution, 10 Limousin-cross suckler cows were blood sampled daily from 5 wk prepartum until first ovulation postpartum for FSH, LH, estradiol (E2), and progesterone assay. Follicular growth was monitored daily by ultrasonography from Days 5 to 10 postpartum until first ovulation. Distributions of circulating FSH isoforms were characterized (n = 4 per group) by chromatofocusing at 1) 18-33 days prepartum, 2) 3-5 days prepartum, 3) the first postpartum FSH rise responsible for emergence of the first follicle wave, and 4) the FSH rise that stimulated the ovulatory follicle wave. The interval to detection of the first postpartum dominant follicle (DF) was 9.6 +/- 0.58 days. The number of DF before first ovulation was 2.1 +/- 0.18, and first ovulation occurred at 28.6 +/- 1.54 days postpartum. Serum E2 concentrations were higher (p = 0.0001) in cows during the 5-wk period prepartum (53.8 +/- 6.29 pg/ml) than in the postpartum period up to first ovulation (1.5 +/- 0.15 pg/ml). In late pregnancy, there was an absence of recurrent FSH rises and LH concentrations were decreased (p < 0.0001) compared with those in the postpartum period. The emergence of each follicle wave postpartum was preceded by a 2- to 4-day rise in FSH concentrations. The pattern of FSH isoform distribution did not differ (p > or = 0.75) between the pre- and postpartum periods.     

Selection, dominance and atresia of follicles during the oestrous cycle of heifers

This study examined the correlation between measurement of follicle growth by ultrasound, and measurement of intrafollicular ratios of oestradiol and progesterone concentrations and the serum concentrations of FSH during selection, dominance and atresia or ovulation of dominant follicles in heifers. Heifers were ovariectomized on days 0 (before LH surge), 1 (after LH surge, preovulation), 1 (postovulation), 3, 6 and 12 of the oestrous cycle. Blood samples were collected at 4-6 h intervals. After ovariectomy all follicles > or = 5 mm were measured and follicular fluid was aspirated. Follicles were classified by size according to ultrasound (F1, largest; F2, second largest; F3, all remaining follicles > or = 5 mm) and by the ratio of oestradiol:progesterone concentrations. During the follicular phase, a single dominant oestrogen-active follicle increased in diameter while serum concentrations of LH increased and FSH decreased (P < 0.05). On day 1 (after LH surge, preovulation), serum LH and FSH decreased to pre-surge concentrations (P < 0.0001), while follicle size and intrafollicular progesterone concentration increased and oestradiol concentration decreased (P < 0.05). A dominant nonovulatory follicle, classified as oestrogen-active on days 1, 3 and 6 and oestrogen-inactive on day 12, increased in size from day 1 to day 7 and lost dominance during days 10-12, coincident with the growth of multiple oestrogen-active follicles. The serum FSH concentration increased transiently (P < 0.05) before each new wave of dominant follicular growth. The overall correlation of ultrasound measurements of follicle diameter with measures of follicle size after ovariectomy was high.(ABSTRACT TRUNCATED AT 250 WORDS)     

Changes in gonadotrophin response to gonadotrophin releasing hormone in normal women following bilateral ovariectomy

OBJECTIVE: Pituitary responsiveness to GnRH varies throughout the normal menstrual cycle. We have investigated whether there are differences in the ovarian mechanisms which regulate gonadotrophin secretion between the follicular and the luteal phase of the cycle. DESIGN: Normally ovulating women were studied during the first week following hysterectomy plus bilateral ovariectomy performed either in the mid- to late follicular phase (follicle size 16 mm) or in the early to midluteal phase (5 days post LH peak). The response of LH to a single dose of 10 micrograms GnRH was investigated 2 hours before the operation and every 12 hours after the operation until postoperative day 4 and every 24 hours until day 8. PATIENTS: Fourteen normally cycling premenopausal women with normal FSH (< 10 IU/l). Seven women were ovariectomized in the follicular and 7 in the luteal phase. MEASUREMENTS: Pituitary response to GnRH was calculated as the net increase in FSH (delta FSH) and LH (delta LH) at 30 minutes above the basal value. RESULTS: Basal levels of FSH and LH before the operation were significantly lower in the luteal than the follicular phase (P < 0.05), while those of oestradiol (E2) were similar. Also, similar were delta LH and delta FSH values. Serum progesterone and immunoreactive inhibin (Ir-inhibin) concentrations before the operation were higher in the luteal than the follicular phase (P < 0.05). Following the operation, serum E2, progesterone and Ir-inhibin values declined dramatically, while basal FSH and LH as well as delta FSH values showed a gradual and significant increase. The percentage increase in FSH and LH values (mean +/- SEM) on day 8 after the operation was similar in the follicular (453 +/- 99% and 118 +/- 35% respectively) and the luteal phase (480 +/- 71% and 192 +/- 45% respectively). In contrast to delta FSH, delta LH values after a temporal increase 12 hours from the operation, remained stable in the follicular phase and declined significantly in the luteal phase up to day 4. CONCLUSIONS: Basal gonadotrophin secretion during the normal menstrual cycle is predominantly under a negative ovarian effect. It is suggested that in contrast to FSH, the secretion of LH in response to GnRH is controlled by different ovarian mechanisms during the two phases of the menstrual cycle.     

Follicle stimulating hormone alone supports follicle growth and oocyte development in gonadotrophin-releasing hormone antagonist-treated monkeys

Both follicle stimulating hormone (FSH) and luteinizing hormone (LH) are proposed requirements for follicular growth and steroidogenesis; however, the role of LH in primate folliculogenesis is unclear. Follicular stimulation by recombinant human FSH (n = 5) with and without recombinant LH (1:1; n = 6) following 90 days of gonadotrophin-releasing hormone (GnRH) antagonist (Antide) treatment in macaques was evaluated. Human chorionic gonadotrophin (HCG) was administered when six follicles > or = 4 mm were observed. Oocytes were aspirated 27 h later and inseminated in vitro. Chronic Antide reduced serum oestradiol and bioactive LH to concentrations observed in hypophysectomized rhesus monkeys. Multiple follicular growth required a longer interval following recombinant FSH (12 +/- 1 days) than recombinant FSH+recombinant LH (9 +/- 0.2 days), but the total number of follicles/animal did not differ between groups. The day prior to HCG, oestradiol concentrations were 4-fold less following recombinant FSH compared to recombinant FSH+recombinant LH. With recombinant FSH, more oocytes completed meiosis to metaphase II (51%) and fertilized (89 +/- 5%) relative to recombinant FSH+recombinant LH (12 and 52 +/- 11% respectively). Follicular growth and maturation in LH-deficient macaques occurred with FSH alone. Thus, LH is not required for folliculogenesis in primates. Higher fertilization rates following follicular stimulation with FSH alone suggest that the presence of LH with FSH (1:1) during the pre-ovulatory interval impairs gametogenic events in the periovulatory period.     

Follicle stimulating hormone-granulosa cell axis involvement in the antifolliculotrophic effect of low dose mifepristone (RU486)

This study was designed to assess the involvement of follicle stimulating hormone (FSH)-granulosa and luteinizing hormone (LH)-theca axes in the antifolliculotrophic effect of mifepristone. Plasma gonadotrophins, including plasma LH bioactivity and pulsatility, oestradiol, testosterone and inhibin concentrations, and follicular growth were monitored in volunteer women treated with placebo or mifepristone in two consecutive cycles. Mifepristone was given either as a single dose of 5 mg (n = 7) when the leading follicle had reached a diameter between 12 and 14 mm, or as a multiple dose of 5 mg/day for 3 days, beginning when the leading follicle had reached a diameter between 14 and 16 mm (n = 5) or between 6 and 11 mm (n = 5). Following the single dose of mifepristone, follicular growth and the accompanying increase in plasma oestradiol were arrested at 12 and 36 h respectively without changes in gonadotrophin or testosterone serum concentrations. The 3 day regimen arrested follicular growth and oestradiol rise and decreased plasma inhibin concentrations when follicles were larger than 12 mm at the onset of treatment. These results indicate that the antifolliculotrophic action of mifepristone is associated with a selective compromise of the FSH-granulosa axis of dominant follicles that have passed a critical stage of growth.     

Modulation of the action of gonadotrophin surge-attenuating factor by gonadotrophin-releasing hormone

Gonadotrophin surge-attenuating factor (GnSAF) is a putative non-steroidal ovarian factor which attenuates the luteinizing hormone (LH) surge in superovulated women through the reduction of the pituitary response to gonadotrophin-releasing hormone (GnRH). The mechanism of action of GnSAF on gonadotrophin secretion was further studied by investigating six normally ovulating women in two cycles--a spontaneous and a follicle-stimulating hormone (FSH)-treated cycle. The response of the pituitary to five consecutive pulses of GnRH was investigated in late follicular phase (follicle size 15 mm) of both cycles. GnRH pulses, 10 micrograms each, were injected i.v. every 2 h and LH was measured in blood samples taken before and 30, 60 and 120 min after each pulse. FSH was injected daily at the fixed dose of 225 IU starting on cycle day 2. Peak values of LH increment occurred 30 min after each pulse. However, maximal LH increment occurred in both cycles after the second GnRH dose. In the FSH cycles the response of LH to the first three pulses was significantly attenuated compared with the spontaneous cycles, while the response to the fourth and fifth pulses was similar in the two cycles. In both cycles, LH increment 30 min post GnRH (net increase above the previous value) was similar after the fourth and fifth pulses. Serum concentrations of oestradiol and immunoreactive inhibin, although higher in the FSH cycles, remained stable throughout the GnRH experimental period in both cycles. These results demonstrate that multiple submaximal doses of GnRH can override the attenuating effect of GnSAF on LH secretion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Enhanced bradycardia induced by beta-adrenoceptor antagonists in rats pretreated with isoniazid

Recent studies indicate that the midcycle gonadotropin surge in the human occurs without an increase in hypothalamic gonadotropin-releasing hormone (GnRH) pulse frequency. In addition, previous studies employing a GnRH antagonist to provide a semiquantitative estimate of endogenous GnRH secretion suggest that the overall amount of GnRH secreted is decreased at the time of the surge. To investigate the hypothesis that a normal gonadotropin surge can be generated in the human with a decreased amount of GnRH at the midcycle, 7 GnRH-deficient subjects underwent two cycles of a physiologic regimen of intravenous pulsatile GnRH therapy. In the control cycle, 75 ng/kg/bolus of GnRH, a dose known to be sufficient for folliculogenesis, was administered throughout the cycle, using physiological frequencies. In a second cycle, the bolus dose of GnRH was decreased by one-half log order to 25 ng/kg just prior to the luteinizing hormone surge and returned to 75 ng/kg after documented ovulation. All cycles were ovulatory. The peak luteinizing hormone level (77.4 +/- 9.7 vs. 67.5 +/- 17.6 IU/l) did not differ between the control and decreased GnRH cycles. There was no difference in the peak serum estradiol level (475.8 +/- 144.1 vs. 493.2 +/- 93.0 pg/ml), follicular phase length (15.0 +/- 1.3 vs. 14.8 +/- 0.6 days), or progesterone level (22.4 +/- 5.1 vs. 34.8 +/- 5.7 ng/mg) on day 6 of the luteal phase in the control and decreased GnRH cycles, respectively. Three pregnancies were achieved in each of the control and reduced GnRH cycles. We conclude that a decreased overall amount of GnRH generates a normal midcycle gonadotropin surge and has no significant impact on luteal phase adequacy or fertility. These results provide further evidence that a decrease in endogenous hypothalamic GnRH secretion may occur at the midcycle in normal women. This study also provides evidence that the GnRH requirements for normal follicular and luteal phase dynamics may well be greater than those required for generation of a normal midcycle gonadotropin surge and ovulation in women.     

Role of diameter differences among follicles in selection of a future dominant follicle in mares

Follicles > or = 5 mm were ablated in pony mares by a transvaginal ultrasound-guided technique on Day 10 (ovulation = Day 0). Follicle emergence (at 15 mm, experiment 1; at 6 mm, experiment 2) and development of the new wave was monitored by transrectal ultrasound. Deviation was defined as the beginning of a marked difference in growth rates between the two largest follicles. In experiment 1, mares were grouped (n = 4 per group) into controls, ablation-controls (ablations at Day 10 only), and a two-follicle model (periodic ablation sessions so that only the two largest follicles developed). There were no significant indications that the two-follicle model altered follicle diameters, growth rates, or time intervals of the two retained follicles at or between events (follicle emergence, deviation, and ovulation). In experiment 2, the two-follicle model (n = 14) was used for follicle and hormonal characterization and hypothesis testing, without the tedious and error-prone necessity for tracking many (e.g., 20) individual follicles. The future dominant follicle emerged a mean of 1 day earlier (p < 0.008) than the future subordinate follicle, the growth rates for the two follicles between emergence and deviation (6 days later) did not differ, and the dominant follicle was larger at the beginning of deviation (23.1 +/- 0.8 mm versus 19.6 +/- 0.9 mm; p < 0.0001). Mean FSH and LH concentrations increased (p < 0.05) concomitantly from emergence of the future dominant follicle and peaked 3 days later when the follicle was a mean of 13 mm. Thereafter, the two hormones disassociated until ovulation: FSH decreased and LH increased. Results supported the hypothesis that the future dominant follicle has an early size advantage over future subordinate follicles and indicated that the advantage was present as early as 6 days before deviation.     

Follicular fluid hormone concentrations after ovarian stimulation using gonadotropin preparations with different FSH/LH ratios. I. Comparison of an FSH-dominant and a purified FSH preparation

OBJECTIVE: A small amount of LH is necessary for 17beta-estradiol production in the ovarian follicle. Human menopausal gonadotropin (hMG) contains equal amounts of FSH and LH activity, whereas recombinant FSH is a gonadotropin preparation without LH. The aim of the present randomized study was to investigate whether ovarian stimulation treatment with recombinant FSH or hMG resulted in different steroidal composition of follicular fluid. METHODS: Antral fluid from mature follicles was collected in in vitro fertilization cycles and concentrations of testosterone, androstenedione, estrone, estradiol, progesterone, FSH, and LH were determined. Seven patients (27 samples) were treated with hMG, 6 patients (22 samples) with recombinant FSH. RESULTS: Androgen, estrogen, progesterone, and FSH concentrations in follicular fluid tended to be lower in the group treated with recombinant FSH, but the variation was large and differences were statistically not significant. CONCLUSION: Treatment with a gonadotropin preparation containing no LH resulted in adequate androgen and estrogen levels in antral fluid of the ovarian follicle in women with normal endocrine profiles, even during pituitary suppression by a GnRH agonist. Apparently, the amount of endogenous LH was sufficient for steroid production within the follicle.     

Does corpus luteum locally affect follicular growth negatively?

In this study bilateral ovarian follicular growth during the luteal phase was investigated in relation to the ovary where ovulation occurred. The diameter of the largest follicle in the contralateral ovary without corpus luteum and in the ipsilateral ovary with corpus luteum was measured using vaginosonography in a total of 66 natural cycles of 27 normally cycling women undergoing treatment with intrauterine insemination (IUI). None of the women received ovarian stimulation or luteal support. Follicles from 2 to 11 mm in diameter were measured in early luteal phase (day +1 to +4), mid-luteal phase (day +5 to +9) and late luteal phase (day +10 onwards). The mean diameters of the largest follicle in the contralateral ovary without corpus luteum during the early, mid- and late luteal phases were 6.81 +/- 1.33 (mean +/- SD), 6.14 +/- 1.29 and 5.71 +/- 1.17 mm respectively, while those of the ipsilateral ovary with corpus luteum were 6.48 +/- 1.40, 5.65 +/- 1.47 and 4.98 +/- 1.19 mm respectively. While there was no significant difference during the early luteal phase, the mean diameter of the largest follicle in the ipsilateral ovary with corpus luteum was significantly smaller than that of the contralateral ovary without corpus luteum during the mid-luteal phase (P < 0.004) and the late luteal phase (P < 0.0005). These results indicate that the corpus luteum locally affects neighbouring follicular growth negatively during the luteal phase of the menstrual cycle, with the most pronounced effect expressed in the mid- and late luteal phases.     

The midcycle gonadotropin surge in normal women occurs in the face of an unchanging gonadotropin-releasing hormone pulse frequency

The midcycle gonadotropin surge is a critical event in normal reproductive cycles and requires functional integration of the hypothalamus, pituitary, and ovary. To determine whether a change in GnRH frequency occurs coincident with the onset or termination of the surge in normal women, 20 studies were performed at a sampling interval of every 5 min for up to 36 h. The frequency of pulsatile GnRH secretion was assessed by the use of two surrogate markers of its secretion, LH and free alpha-subunit (FAS). The timing of the studies was prospectively determined by serial ultrasound and previous cycle history, whereas measurements of LH, FSH, estradiol, and progesterone in daily blood samples were used retrospectively to locate the frequent sampling study in relation to the day of ovulation in each individual. The frequent sampling studies were divided into late follicular phase (LFP; days -4 to -2) and early, mid-, and late portions of the midcycle surge (days -1 to 1) in relation to the 95% confidence limits of the LH peak derived from daily samples in 69 normal ovulatory women. The patterns of LH and FAS secretion were pulsatile at all times during the midcycle surge. The amplitude of LH pulsations increased from the LFP and early surge to the midportion of the midcycle surge (5.9 +/- 6 and 15.1 +/- 5 vs. 39.0 +/- 3 IU/L; P < 0.0001) and decreased from the mid- to the late portion of the surge (13.4 +/- 5 IU/L; P < 0.0001). Likewise, the amplitude of FAS pulse increased from the LFP and early surge to the midportion of the surge (82.4 +/- 59 and 153.1 +/- 50 vs. 421.4 +/- 35 ng/L; P < 0.0001) and decreased from the mid- to the late portion of the surge (190.8 +/- 49 ng/L; P < 0.0002). Although there was excellent concordance of pulsatile secretion of LH and FAS, significantly more pulses of FAS were detected than of LH (P < 0.0001). There was no change in frequency (expressed as interpulse interval) between the LFP and the early and midportions of the surge for LH (70.0 +/- 8, 67.5 +/- 7, and 65 +/- 5 min, respectively) or FAS (55.1 +/- 7, 54.6 +/- 6, and 60.0 +/- 4 min). However, there was an increase in LH interpulse interval (decrease in pulse frequency) in the late portion of the surge (87.0 +/- 6 min) compared to the early and midportions of the surge (P < 0.02 and P < 0.0005, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)     

Effect of constant administration of a gonadotropin-releasing hormone agonist on reproductive activity in mares: induction of ovulation during seasonal anestrus

The potential of a gonadotropin-releasing hormone (GnRH) agonist (goserelin acetate), delivered constantly for 28 days via a subcutaneous depot, to induce ovulation in seasonally anestrous mares, was investigated. Two experiments were conducted, in which a range of doses (30 to 240 micrograms/mare/d) was examined. Mares were selected on the basis of lack of substantial follicular development (follicle diameter < 20 mm determined ultrasonically) and low serum concentrations of luteinizing hormone (LH) and progesterone. Constant administration of the GnRH agonist-induced ovulation in anestrous mares, but a dose-response relation was not observed. Furthermore, with identical doses tested in consecutive or alternate years, considerable variation was observed in the ovulatory response. In general, ovulation in all treated mares was accompanied by increased circulating concentrations of LH and a decrease in follicle-stimulating hormone values. Ovulation was preceded by an increase in estradiol and LH concentrations. In mares in which ovulation did not occur, concentration of LH increased during agonist treatment, whereas that of follicle-stimulating hormone either increased or did not change. It was concluded that constant administration of GnRH agonists may induce ovulation in mares during seasonal anestrus; however, percentage of mares ovulating and the lack of reproducibility of effect indicate that this approach is inappropriate for use as a reliable method to manipulate breeding activity in commercial broodmares.     

Follicular development and hormonal levels following highly purified or recombinant follicle-stimulating hormone administration in ovulatory women and WHO group II anovulatory infertile patients

PURPOSE: Our purpose was to compare ovarian performance and hormonal levels, after ovulation induction, in both normal ovulatory women undergoing intrauterine insemination (group 1) and World Health Organization (WHO) group II anovulatory infertile patients (group 2), using two different gonadotropin drugs. METHODS: Patients (n = 20 per group) were treated during consecutive cycles, using the same stimulation protocol, with highly purified urinary FSH (HP-FSH) in the first treatment study cycle and recombinant FSH (rFSH) in the second one. Patients in group 1 were treated according to a late low-dose technique, and WHO group II anovulatory patients (group 2) received chronic low-dose FSH therapy. RESULTS: Compared with HP-FSH, treatment with rFSH in group 2 required significantly less ampules of drug to induce follicular development but resulted in significantly higher plasma levels of estradiol and inhibin A on the day of human chorionic gonadotropin injection. No differences were found when both treatment modalities were compared in group 1. CONCLUSIONS: rFSH is more efficacious than urinary HP-FSH for ovulation induction in WHO group II anovulatory infertile patients as assessed by follicular development, hormonal levels, and the amount of FSH required.     

Evidence suggesting an additional control mechanism regulating episodic secretion of luteinizing hormone and follicle stimulating hormone in pre-pubertal children and post-menopausal women

The possible differential regulation of pulsatile follicle stimulating hormone (FSH) and luteinizing hormone (LH) secretion in pre-pubertal children and in post-menopausal women was investigated. Children were studied for 4 h and post-menopausal women for 6 h; blood samples were taken every 10 min. Post-menopausal women were studied before and 21 days after administration of a single i.m. dose of gonadotrophin-releasing hormone (GnRH) analogue. Eight post-menopausal women and 18 children (nine boys and nine girls) were enrolled. The children were divided into two groups: A, at Tanner stages 0-1 (four boys and three girls); B, at Tanner stage 2-3 (five boys and six girls). Plasma LH and FSH concentrations were determined using an immunofluorimetric assay. Time series were analysed and the specific concordance (SC) index was computed to determine the degree of concordance between episodes of LH and FSH secretion. While children of group A had LH concentrations below the minimal detectable dose of 0.1 IU/l, group B showed measurable LH plasma concentrations (1.4 +/- 0.3 IU/l, mean +/- SEM). Plasma FSH concentrations were detectable in both groups. Group A showed FSH plasma concentrations significantly lower than those of group B (0.75 +/- 0.2 and 1.95 +/- 0.4 IU/l respectively; P < 0.05), but FSH pulse frequency was higher in group A (P < 0.05). Children of group B showed significant concomitance of LH and FSH secretory events at time 0 (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Low levels of follicle-stimulating hormone receptor-activation inhibitors in serum and follicular fluid from normal controls and anovulatory patients with or without polycystic ovary syndrome

In patients with normogonadotropic anovulation, either with or without polycystic ovary syndrome (PCOS), factors interfering with FSH action may be involved in arrested follicle development. The aim of this study is to assess whether factors inhibiting FSH receptor activation are elevated in serum or follicular fluid from anovulatory patients, as compared with regularly cycling women. For this purpose, a Chinese hamster ovary cell line, stably transfected with the human FSH receptor, has been applied. FSH-stimulated cAMP secretion in culture medium was measured in the presence of serum or follicular fluid. Chinese hamster ovary cells were stimulated with a fixed concentration of FSH (3 or 6 mIU/mL) to mimic FSH levels in serum or follicular fluid. Samples were added in concentrations ranging from 3-90% vol/vol to approach protein concentrations occurring in serum or follicular fluid. In the presence of 10% vol/vol serum from regularly cycling women (n = 8), FSH-stimulated cAMP production was inhibited to 42 +/- 2% (mean +/- SEM of 2 experiments, each performed in duplicate) of cAMP production in the absence of serum, whereas a similar cAMP level (up to 38 +/- 4% of the serum-free level) was observed at higher concentrations of serum (30-90% vol/vol). The inhibition of FSH-stimulated cAMP production in the presence of serum samples from normogonadotropic anovulatory patients, without (n = 13) or with (n = 16) PCOS, was similar to controls. Follicular fluid samples (n = 57) obtained during the follicular phase in 25 regularly cycling women and follicular fluid samples (n = 25) from 5 PCOS patients were tested in a slightly modified assay system. In the presence of 10 or 30% (vol/vol) follicular fluid, FSH-stimulated cAMP levels were decreased to 68 +/- 2% and 55 +/- 2% (mean +/- SEM of a single experiment in triplicate) of the cAMP levels in the absence of follicular fluid, respectively. There was no correlation between the degree of cAMP inhibition and follicle size, steroid content (androstenedione or estradiol concentrations), or menstrual cycle phase. Furthermore, no differences in inhibition were found, comparing PCOS follicles with size- and steroid content-matched follicles obtained during the normal follicular phase. It is concluded that inhibition of FSH receptor activation by proteins present in serum or follicular fluid is constant (60 and 40%, respectively) and independent from the developmental stage of the follicle, either during the normal follicular phase or in patients with normogonadotropic anovulation. Inhibition of FSH receptor activation may be of limited significance for normal and arrested follicle development.     

Porcine follicle-stimulating hormone treatment of gilts during an altrenogest-synchronized follicular phase: effects on follicle growth, hormone secretion, ovulation, and fertilization

Porcine FSH (SUPER OV), containing .03% LH activity, and equine chorionic gonadotropin (eCG) were administered during an altrenogest-synchronized follicular phase to determine their effects on follicle development, estrus, ovulation, and fertilization. Treatments were made by i.m. injection starting on d 1 (24 h after the last feeding of altrenogest): 1) saline, once, n = 14; 2) eCG (1,200 to 1,500 IU) once, n = 32; 3) FSH 14 (n = 2) or 21 (n = 6) NIH-FSH-S1 units/100 kg BW, divided among six injections at 12-h intervals (FSH14/21); 4) FSH, 28 NIH-FSH-S1 units/100 kg BW, divided among six injections at 12-h intervals, n = 12; and 5) FSH, 28 NIH-FSH-S1 units/100 kg BW and 100 IU hCG, two or six injections at 12-h intervals (FSH28+hCG), n = 13. Gilts were injected with 750 IU of hCG on d 5 to ensure ovulation. Twenty-eight eCG- and FSH-injected gilts (n = 6, 8, and 11 on treatments 3, 4, and 5, respectively) were bred and laparotomized on d 7 to recover ova and record ovulation rate. The mean number of ovulations and large (6- to 10-mm) follicles, respectively, on d 7 were as follows: saline (17, .7), eCG (43, .9), FSH14/21 (15, .6), FSH28 (12, 16), and FSH28+hCG (32, 21). Plasma FSH concentrations were at least threefold higher (P < .05) in gilts treated with FSH than in gilts not treated with FSH. The percentage in estrus was higher (P < .05) for saline- and eCG-treated gilts (100 and 87%, respectively) than for FSH-treated gilts (53%). Proportion of FSH28+hCG-treated gilts with fertilized ova (27%) was lower than for other groups (79 to 100%). In summary, the 3-d high dose FSH treatment (FSH28 and FSH28+hCG) during an altrenogest-synchronized follicular phase increased the number of potentially ovulatory follicles, but this potential benefit was not realized because many follicles failed to ovulate. The co-injection of low doses of hCG (FSH28+hCG) increased the ovulation rate and estradiol secretion but reduced ova recovery and fertilization rate compared with eCG and the other FSH treatments.