Effects of guaiazulene on in vitro bovine embryo production and on mRNA transcripts related to embryo quality.

Reactive oxygen species (ROS) are between the major contributors for the reduced rate of in vitro bovine embryo production. It is believed that they can cause abnormal meiosis of oocytes, developmental arrest or cell death of embryos. Reports on the effectiveness of various antioxidants on embryo yield are rather conflicting mainly due to the nature and the concentration of the substances used. Here we report the effects of guaiazulene--an exogenous antioxidant, without known properties that could interfere with the biological process of IVF--on embryo development and on the quality of the produced blastocysts. Bovine cumulus oocyte complexes (COCs) were aspirated from abattoir ovaries and COCs were matured in TCM199 with FCS and EGF at 39 °C under an atmosphere of 5% CO(2) in air, with maximum humidity. After 24 h oocytes were inseminated with frozen/thawed semen and co-incubated for further 24 h. Zygotes were cultured in groups of 25 in 25 µl of SOF with 5% FCS at 39 °C under an atmosphere of 5% CO(2) , 5% O(2) in air with maximum humidity. In the first experiment the maturation medium was modified with addition of 0.1 mM of G (n = 497), or 0.01 mM of guaiazulene (n = 468), 0.05% DMSO--the guaiazulene diluent (Control(+), n = 467), and 459 oocytes were used as Control(-). In the second experiment, the culture medium was modified with the addition of 0.1 mM of guaiazulene (n = 344), 0.01 mM of guaiazulene (n = 345), 0.05% DMSO (Control(+), n = 347) and 355 were the Control(-). Blastocyst yield was recorded on days 6, 7, 8 and 9. Day 7 blastocysts from each experiment and group were snap frozen and stored for mRNA extraction. Quantification of transcripts for mRNA of genes related to metabolism (AKR1B1, PTGS2, GADPH, SLC2A5, G6PD); oxidation (GPX1); and implantation (PLAC8) was carried out by real time quantitative RT-PCR. Data for embryo development and on transcript abundance were analysed by χ(2) and anova respectively. In the first experiment no differences were found between groups in terms of cleavage rate (Control(-): 74.20%; Control(+): 74.58%; 0.01 mM: 71.61%; 0.1 mM: 71.63%) or day 9 blastocyst yield (Control(-): 28.26%; Control(+): 25.80%; 0.01 mM: 25.86%; 0.1 mM: 25.25%). In the second experiment, cleavage rate tended to be higher in 0.01 mM group than in Control(-) (77.87% vs 71.41% respectively, p = 0.07). No other differences were detected in cleavage rate (Control(+): 71.32%; 0.1mM: 72.75%) or in the overall blastocyst yield on day 9 (Control(-): 25.50%; Control(+): 26.71%; 0.01 mm: 29.58%; 0.1 mM: 25.75%). In both experiments the relative abundance of genes studied varied between groups but these differences were not statistically significant. Our results imply that oxidation has minimal effect on the in vitro embryo production. Guaiazulene, a compound possessing no biological properties other than those of a strong antioxidant, while it increased cleavage rate, it failed to improve either the blastocyst formation rate, or the quality of the produced embryos under 5% O(2) .

Evidence for non genomic action of 17ß estradiol on transepithelial resistance of human fetal membranes.

BACKGROUND: The role of hormones in the transport mechanisms of human fetal membranes in pregnancy is unclear. Estrogens are essential hormones in pregnancy and they play an important role in the ion transport via membranes. AIM: The aim of this study was to investigate the effect of 17ß-estradiol on transepithelial electrical resistance in the human amniochorion. MATERIAL AND METHODS: Specimens of human fetal membranes were obtained. 17ß-estradiol, tamoxifen and their combination were added in an Ussing chamber. Transepithelial resistance was measured before and after the addition of each solution. RESULTS: An increase in transepithelial resistance was seen after the addition of estradiol to both sides of the membranes. The effect was rapid with a peak at the 1st min of application and dose-depended. Tamoxifen, caused a similar effect but smaller in magnitude and shorter in duration. Tamoxifen in combination with estradiol inhibited only in part the action of estradiol. CONCLUSIONS: These results suggest that estradiol induces a rapid increase of transepithelial resistance in human fetal membranes in vitro via a non-genomic pathway. It is possible those changes in transepithelial resistance play a role in the control of permeability of human amniochorion.

The effect of estrogens on plasma ghrelin concentrations in women.

BACKGROUND: Data regarding the possible effects of estrogen on ghrelin secretion in humans are limited and contradictory. AIM: To investigate the effect of estradiol (E2) on ghrelin levels in normal pre- and post-menopausal women. SUBJECTS AND METHODS: A total of 21 women divided into 3 groups, i.e.13 normally cycling women (no.=7, group 1 and no.=6, group 2) and 8 post-menopausal women (group 3). Women of group 1 received increasing doses of E2 through skin patches from cycle days 3 to 5. Women of group 2, underwent total abdominal hysterectomy plus bilateral salpingo-oophorectomy (TAH+BSO) on cycle day 3. Women of group 3 received po increasing doses of E2 valerate for 15 days. Acylated ghrelin and E2 were measured in all blood samples. RESULTS: In group 1, plasma ghrelin levels did not show any significant changes for the week following cycle day 3. In group 2, ghrelin levels were similar before and after TAH+BSO and remained stable during the first 7 post-operative days. In group 3, no significant changes in plasma ghrelin levels were seen during the 15 days of E2 administration. CONCLUSIONS: The present study demonstrates for the first time that ghrelin values were not affected either by exogenous short-term estrogen administration to pre- and post-menopausal women or following ovariectomy in pre-menopausal women. It is suggested that ovarian hormones are not involved in the regulation of ghrelin secretion in women.

Modulating effect of leptin on basal and follicle stimulating hormone stimulated steroidogenesis in cultured human lutein granulosa cells.

BACKGROUND: In vitro data have shown conflicting results in terms of the effect of leptin on granulosa cells steroidogenesis. AIM: The aim of the present study was to investigate the effect of low and high doses of leptin on basal and FSH-induced steroids secretion by human luteinized granulosa cells in culture. MATERIALS AND METHODS: Granulosa cells were obtained from normal women undergoing in vitro fertilization (IVF) treatment and were cultured in serum-free conditions for 72 h. A one-way analysis of variance design was set to study the effect of leptin on basal and FSH-induced steroidogenesis. RESULTS: Leptin affected basal estradiol and progesterone secretion in a dose-related manner. In particular, leptin at low concentrations stimulated the secretion of estradiol (1 and 10 ng/ml) and progesterone (10 ng/ml), while at a high concentration (100 ng/ml) it suppressed the secretion of both steroids. A dose-related effect of leptin on FSH-induced steroidogenesis was not evident, since only the suppressive effect of the high concentration of leptin (100 ng/ml) reached statistical significance for both steroids. CONCLUSIONS: These results demonstrate that leptin affects the secretion of steroids in luteinized granulosa cells in a dose-dependent manner. Although a physiological role for leptin is possible, it is suggested that this protein is a mediator of negative rather than positive influential interactions on ovarian function that may compromise fertility.

Effect of an OT antagonist on the control of the midcycle LH surge in women.

OBJECTIVE: Data in women regarding the role of OT in LH secretion during the LH surge are conflicting. As in previous studies blood samples for LH measurements were taken infrequently, we re-examined this matter in women with a fully characterized midcycle LH surge. DESIGN: Normal women were studied over two cycles. When the dominant follicle reached a diameter of either 16-17 mm (Group 1) or 18-19 mm (Group 2), the women were infused intravenously for 3 h with normal saline (cycle-1) or atosiban (cycle-2). PATIENTS: Fifteen women (10 in group 1 and 5 in group 2) aged 23-35 years. MEASUREMENTS: Blood samples were obtained every 6 h to characterize the midcycle LH surge. RESULTS: The time interval (mean +/- SEM) from the start of the infusion to the onset of the LH surge in the two cycles was 46.8 +/- 4.8 and 45.6 +/- 9.6 h in group 1 and 6.0 +/- 2.4 and 7.5 +/- 2.8 h, respectively, in group 2. LH values during the LH surge were similar in the two cycles except in group 1 at the point of 30 h at which LH value in cycle-2 (41.2 +/- 4.6 mIU/ml) was significantly lower than in cycle-1 (52.8 +/- 3.4 mIU/ml, P < 0.05). Nevertheless, in each group, the area under the curve for LH was similar in the two cycles. CONCLUSIONS: Antagonism of endogenous OT action by atosiban does not alter the LH profile during a fully characterized midcycle LH surge, suggesting that OT is not a major regulator of LH secretion in women.

Immature teratoma in pregnancy: a case report and literature review.

BACKGROUND: The management of a Stage I immature teratoma during pregnancy with a review of the literature is reported. CASE REPORT: A growing adnexal mass was removed at 12 weeks of gestation. Although the frozen section was negative, because of intraoperative clinical suspicion, a right salpingo-oophorectomy and surgical staging were performed. Histological examination revealed a Stage Ia, grade 1 immature ovarian teratoma. Appropriate surgical staging enabled avoidance of chemotherapy despite the unexpected histological diagnosis. The pregnancy was terminated because of fetal distress, with cesarean section at 34 weeks of gestation. At that time the peritoneal cavity was inspected and biopsies were taken as in second-look laparotomy. Two years after the first operation the patient remains disease free. CONCLUSION: For adnexal masses removed during pregnancy frozen section is useful but when there is clinical suspicion surgical staging must be performed.

Xanthogranulomatous salpingitis: report of three cases and comparison with a case of pseudoxanthomatous salpingitis.

Xanthogranulomatous inflammation, an uncommon form of chronic inflammation, has been described in several organs including those of the female genital tract. A rare condition described as pseudoxanthomatous salpingitis or pseudoxanthomatous salpingiosis, which is often associated with endometriosis, has been distinguished from xanthogranulomatous inflammation of the fallopian tube based on its histological features. In the present report three cases of xanthogranulomatous salpingitis and one case of pseudoxanthomatous salpingitis are presented and their clinical, pathological and histochemical features are compared.

Rapid effect of progesterone on transepithelial resistance of human fetal membranes: evidence for non-genomic action.

1. The factors that regulate human fetal membrane transport mechanisms are unknown. The aim of the present study was to investigate the effect of progesterone on transepithelial electrical resistance (R(TE)) in the human amniochorion. 2. Fetal membranes from uncomplicated term pregnancies were obtained immediately after vaginal or Caesarean deliveries. Intact pieces were mounted as planar sheets separating an Ussing chamber. Progesterone (10(-4) to 10(-7) mol/L), mifepristone (10(-4) to 10(-8) mol/L) and combinations of progesterone plus mifepristone were applied to the chambers facing the fetal or maternal sides of the membrane. The R(TE) was measured before and 1, 5, 10, 15, 20, 25, 30, 45 and 60 min after each solution was added (at 37 degrees C). The R(TE) was calculated in Omega.cm(2), according to Ohm's law. 3. The mean (+/-SEM) basal value of R(TE) before the application of any substance in all experiments was 29.1 +/- 0.4 Omega.cm(2). The net change in the R(TE) (Delta R(TE)) in relation to the basal value was calculated in each experiment. Progesterone, mifepristone and the combination of progesterone and mifepristone induced a rapid, surge-type increase in R(TE) during the 1st min on both sides of the membrane. The combination of progesterone plus mifepristone exerted a synergistic action. The effect was stronger on the fetal side than on the maternal side for all substances tested (P < 0.05). The highest Delta R(TE) during the 1st min on the fetal side was seen with the combination of progesterone plus mifepristone (4.0 +/- 0.3 Omega.cm(2)) and the lowest Delta R(TE) occurred with mifepristone (1.5 +/- 0.1 Omega.cm(2)). 4. The present results demonstrated that the R(TE) of human fetal membranes increases rapidly in response to progesterone. It is possible that changes in R(TE) play a role in the control of membrane permeability during pregnancy.

Oxytocin is not important for the control of gonadotrophin secretion in the late follicular phase of the cycle.

OBJECTIVE: To study the role of oxytocin in basal and GnRH-induced gonadotrophin secretion in normal women. DESIGN: Normal women were studied in three cycles. When the diameter of the leading follicle was 15-16 mm, the women were infused intravenously (i.v.) for 3 h with normal saline (cycle 1), atosiban (cycle 2) or oxytocin (cycle 3). PATIENTS: The study included 12 normally cycling women aged 23-38 years. MEASUREMENTS: After cessation of treatment, two injections of GnRH, 10 microg each, were administered i.v. 2 h apart and blood samples were collected every 30 min for a total of 240 min. The 30-min pituitary response (sensitivity) to a single GnRH injection (10 microg i.v.) was investigated thereafter every 12 h from the end of the 3-h infusion until the day of LH surge onset. RESULTS: No significant differences in LH and FSH response to GnRH (sensitivity and reserve) during the 240-min experiment were found between the three cycles. The time of LH surge onset from the initiation of the infusion was similar in the three cycles. Also similar in the three cycles were oestradiol (E2) and gonadotrophin levels as well as the 30-min response to GnRH for 48 h following the 3-h infusion. CONCLUSIONS: The present study demonstrates that neither exogenous oxytocin administration nor blockage of endogenous oxytocin action influences pituitary sensitivity to GnRH in cycling women.

Endothelin-3 and PRL levels in the maternal and fetal circulation at delivery.

OBJECTIVE: The aim of the present cross-sectional study was to test the hypothesis that endothelin-3 (ET-3) is involved in PRL secretion via systemic hormonal interaction during labor. MATERIALS AND METHODS: Fifty healthy pregnant women with singleton pregnancies were included in the present study. At delivery, blood samples were drawn from umbilical vein and artery. At the same time, a blood sample was obtained from a peripheral vein of the mother. In all blood samples, plasma ET-3 and serum PRL concentrations were determined. The main outcome measures were the differences between maternal peripheral blood, umbilical artery and vein in terms of ET-3 and PRL levels, and the associations between ET-3 and PRL levels. RESULTS: ET-3 values (mean+/-SEM) in umbilical artery did not differ significantly from those in umbilical vein (4.94+/-0.27 vs 5.05+/-0.32 pg/ml) but were in both vessels significantly higher than in maternal vein (1.14+/-0.56 pg/ml, p<0.001). Serum PRL values showed similar patterns. There was a significant positive correlation of the ET-3 levels between umbilical artery and vein (r=0.906, p<0.001), but not between maternal peripheral venous blood and the umbilical vessels. Similar correlations were found for PRL values. However, no significant correlations were found between ET-3 and PRL levels in all vessels studied. CONCLUSIONS: The present study demonstrates for the first time that ET-3 levels are higher in fetal than in maternal circulation at term. The lack of correlation between ET-3 and PRL levels suggests that ET-3 does not play an important endocrine role in the control of maternal and fetal PRL secretion during labor.

Primary retroperitoneal non-Hodgkin lymphoma presenting with torturous generalized pruritus in an elderly.

INTRODUCTION: A case of a rare primary retroperitoneal non-Hodgkin lymphoma (NHL), which presented with torturous generalized pruritus in a 74-year-old female patient is reported METHODS: Case report. RESULTS: Explorative laparotomy was performed after imaging revealed a pelvic mass and an ovarian tumour was suspected. After the frozen section revealed a lymphoma, extensive surgery was omitted. The patient was successfully treated with courses of Bleo-CHOP regimen (complete response) and pruritus resolved entirely after completing the second course of chemotherapy. CONCLUSION: This report indicates the need of thorough investigation of the peritoneal cavity for the presence of NHL in cases presenting as unexplained pruritus in the elderly. In this setting the presence of a retroperitoneal pelvic mass must raise the suspicion for the possibility of the rare retroperitoneal NHL.

Retinoid receptor alpha and Beta expression in serous ovarian tumors.

The expression of retinoid acid receptors alpha (RARalpha) and beta (RARbeta) and estrogen receptor alpha (ERalpha) was assessed by immunohistochemistry and Western blotting in normal ovaries, serous cystadenoma (n = 20), serous borderline (n = 14), and serous ovarian cancer (n = 47) and was correlated in cancer cases with stage, grade, progress-free survival (PFS), and survival. RARalpha was increasingly expressed in benign cystadenomas, borderline, and low-stage and advanced-stage neoplasms (p < 0.001). In stage III, G3 serous carcinoma, increased RARalpha expression was an independent prognostic factor associated with lower chemoresponse to first-line chemotherapy (taxol and carboplatin) and shorter PFS (p < 0.002).RARbeta and ERalpha expression did not correlate with RARalpha tumor characteristics or PFS and survival.

Oestradiol stimulates prolactin secretion in women through oestrogen receptors.

OBJECTIVE: To examine the effects of clomiphene and raloxifene on basal and GnRH-induced prolactin (PRL) secretion in postmenopausal women. DESIGN: Postmenopausal women participated in two experimental procedures a month apart. In one experiment they received raloxifene (180 mg/day) (R-Exp) and in the other clomiphene (150 mg/day) (Cl-Exp). In Group 1, the women (n = 8) received raloxifene or clomiphene for 30 days plus oestradiol via skin patches (100 microg/24 h) for the last 10 days. In Group 2, the women (n = 8) received oestradiol for 30 days plus raloxifene (R-Exp) or clomiphene (Cl-Exp) for the last 10 days. The pituitary response to GnRH (100 microg i.v.) was investigated in all women on days 0, 10, 20 and 30 of each experiment. PATIENTS: The study included 16 healthy postmenopausal volunteer women aged 56-60 years. MEASUREMENTS: Basal levels of PRL and the area under the curve (AUC) of DeltaPRL response to GnRH were calculated. RESULTS: In Group 1, basal levels of PRL and the area under the curve (AUC) of PRL response to GnRH did not change significantly in both experiments. In Group 2, during both experiments basal levels of PRL and the AUC of PRL increased significantly on days 10 (P < 0.05) and 20 (P < 0.05) as compared to day 0 and then they decreased significantly on day 30 as compared to day 20 (P < 0.05). CONCLUSIONS: Our study demonstrates for the first time that raloxifene and clomiphene affect the secretion of PRL in postmenopausal women in a similar manner. It is suggested that oestradiol stimulates the secretion of PRL in women by acting through oestrogen receptors.

Evidence that termination of the estradiol-induced luteinizing hormone surge in women is regulated by ovarian factors.

BACKGROUND: The endogenous LH surge is the result of the estrogen-positive feedback effect. However, the factors that are responsible for the termination of LH surge are not known. OBJECTIVE: The objective of the study was to investigate the mechanism that terminates the LH surge in women. SUBJECTS AND METHODS: Eight normally cycling women (aged 42-48 yr) were investigated in two cycles, i.e. cycle 1 (control) and cycle 2. In cycle 2 total abdominal hysterectomy plus bilateral salpingooophorectomy was performed on d 3. In both cycles, estradiol was administered transdermally at the dose of 100 microg on d 3 and 150 microg on d 4 and 5. Blood samples were obtained every 12 h from d 3 to 5 and every 6 h thereafter until d 9. RESULTS: In both cycles, after suppression of gonadotropins, the women displayed an endogenous LH surge. The time intervals between the commencement of estradiol treatment and the LH surge onset (73.5 +/- 1.5 vs. 76.5 +/- 2.5 h) and peak LH values (11.4 +/- 1.9 vs. 12.4 +/- 3.1 IU/liter) were comparable in the two cycles (mean +/- sem). After peaking, LH values decreased gradually in cycle 1, whereas in cycle 2 they remained stable and were higher than the corresponding values in cycle 1 (P < 0.05). Before the LH surge onset, estradiol values showed in both cycles a preovulatory pattern of changes, but starting 24 h after the onset of the LH surge, they were lower in cycle 2 (P < 0.05). Progesterone levels were similar in both cycles until the day of the LH surge onset, but in cycle 2 they declined thereafter and were lower than in cycle 1 (P < 0.05). CONCLUSIONS: It is suggested that ovarian factors rather than exhaustion of pituitary reserves are important for termination of the endogenous LH surge during the normal menstrual cycle.

Expression of human serum albumin (HSA) mRNA in human granulosa cells: potential correlation of the 95 amino acid long carboxyl terminal of HSA to gonadotrophin surge-attenuating factor.

INTRODUCTION: According to previous studies, gonadotrophin surge-attenuating factor (GnSAF), which is assumed to be produced in human granulosa cells, has a homology with the carboxyl terminal of the human serum albumin (HSA) protein. In an attempt to validate these findings, whole or partial expression of the HSA gene was studied by RT-PCR analysis in human granulosa cells from women undergoing IVF treatment. METHODS: RT-PCR analysis of HSA RNA transcripts in luteinized granulosa cells was done in order to investigate the possible expression of the HSA gene. To ensure the specificity of PCR products, restriction enzyme and sequence analysis were performed. Western blot analysis was carried out to detect the possible expression of the albumin gene in granulosa cells. RESULTS: RT-PCR analysis and sequencing analysis of cDNA from granulosa cells revealed bands identical with those from the positive control for the amino as well as the carboxyl terminal corresponding to HSA gene at the cytoplasmic level. CONCLUSION: We have demonstrated that human granulosa cells express the carboxyl and amino terminal part of the HSA gene in levels comparable to those found in human hepatocytes. It is suggested that the coding gene for GnSAF may be a result of an alternative expression of HSA gene.

The value of a single combined measurement of VEGF, glycodelin, progesterone, PAPP-A, HPL and LIF for differentiating between ectopic and abnormal intrauterine pregnancy.

BACKGROUND: To evaluate whether serum concentrations of the non-placental markers vascular endothelial growth factor (VEGF), glycodelin (GLY) and progesterone (P) and the novel placental markers pregnancy-associated plasmaprotein A (PAPP-A), human placental lactogen (HPL) and leukaemia inhibiting factor (LIF) differ in ectopic pregnancy (EP) when compared with abnormal intrauterine pregnancy (aIUP). METHODS: A prospective clinical study was conducted at the University Hospital of Larissa, Greece. The study included 50 patients admitted with failed pregnancy and suspected ectopic pregnancy that were treated with curettage or laparoscopy and classified as histologically confirmed EPs (n = 27) or histologically confirmed aIUPs (n = 21) (mean gestational age of 7.15 and 7.3 weeks, respectively). Two suspected EPs proved to be normal IUPs and were excluded. VEGF, GLY, P, beta-HCG, PAPP-A, HPL and LIF were measured by enxyme-linked immunosorbent assay (ELISA) methods in a single pre-operative blood sample. RESULTS: The median VEGF concentration was 227.2 pg/ml in the EP group versus 107.2 pg/ml in the aIUP group (P < 0.001), with a suggested threshold value of 174 pg/ml for their differential diagnosis. LIF, P, PAPP-A, HPL and GLY serum measurements did not differ significantly between EP and aIUP. CONCLUSION: VEGF serum levels might be a useful marker in differentiating between EPs and aIUPs.

Alternate day and daily administration of GnRH antagonist may prevent premature luteinization to a similar extent during FSH treatment.

BACKGROUND: This randomized controlled trial was designed to evaluate whether a GnRH antagonist given every other day could prevent premature luteinization in women undergoing IVF/ICSI treatment. METHODS: A total of 73 women receiving ovulation stimulation IVF cycles with recombinant FSH were allocated randomly on cycle day 7 to GnRH antagonist ganirelix in multiple doses (0.25 mg each), either daily (n = 37 women, group 1) or every other day (n = 36 women, group 2) until the day of HCG administration. RESULTS: Serum FSH, LH, estradiol and progesterone values showed similar trends in the two groups. During FSH stimulation, 13 (35%) of the women in group 1 had premature LH rises (> or = 10 IU/l) of which eight (22%) were after the start of antagonist administration. In group 2 there were 14 (39%) LH rises during FSH stimulation of which 10 (28%) were after the start of antagonist administration. Luteinization (serum progesterone >2 ng/ml) occurred in only one woman in each group overall (3%). A significantly smaller total dose of the antagonist was used in group 2 than in group 1 (P < 0.001). The study did not have power to evaluate differences in total dose of FSH, number of oocytes recovered and clinical pregnancy rate, all of which appeared similar in the two groups. CONCLUSIONS: Whether alternate day is as effective as daily administration of ganirelix in preventing premature luteinization should be addressed in a non-inferiority trial powered to evaluate live birth rate.

Effects of clomiphene and raloxifene on gonadotrophin secretion in postmenopausal women: evidence of nongenomic action.

OBJECTIVE: To evaluate the effect of raloxifene (R) and clomiphene (Cl) on FSH and LH secretion in postmenopausal women. DESIGN: Postmenopausal volunteer women participated in two experimental (Exp) procedures. In Group 1, the women received R (180 mg/day orally) for 30 days plus oestradiol (E2) through skin patches (100 microg/24 h) from days 21 to 30 (R-Exp). After a month's break the same women received Cl (150 mg/day orally) for 30 days plus E2 as above (Cl-Exp). In Group 2, the women received E2 for 30 days plus R from days 21 to 30 (R-Exp) and after a month's break they received E2 for 30 days plus Cl from days 21 to 30 (Cl-Exp). Daily doses were as in Group 1. A GnRH test (100 microg intravenously) was performed in all women on days 0, 10, 20 and 30 of each experiment. PATIENTS: Sixteen healthy postmenopausal women were divided into two groups (eight women in each group). MEASUREMENTS: The area under the curve (AUC) of DeltaFSH and DeltaLH response to GnRH (net increase above the basal value) was calculated. RESULTS: In Group 1, basal levels of FSH and LH did not change significantly during the R-Exp, while they decreased significantly in the Cl-Exp (P < 0.001). The addition of E2 did not have any effect. The AUC of LH response to GnRH increased significantly in the R-Exp (P < 0.05) and that of FSH in the Cl-Exp (P < 0.05). In Group 2, basal levels of FSH and LH declined significantly during treatment with E2 in both the R-Exp (P < 0.01) and the Cl-Exp (P < 0.001). However, the addition of Cl (for 10 days) interrupted this decrease, while the addition of R stimulated FSH levels significantly (P < 0.05). E2 suppressed significantly the AUC of LH in both experiments (P < 0.05). The addition of Cl did not affect the AUC in response to GnRH, while the addition of R increased the AUC of both LH and FSH (P < 0.05). CONCLUSIONS: These results demonstrate for the first time that in contrast to Cl, R does not exert oestrogenic effects on basal gonadotrophin secretion. Although the antioestrogenic action of these drugs was evident only after pretreatment with E2, both R and Cl stimulated GnRH-induced gonadotrophin secretion in oestrogen-deprived women. It is hypothesized that these two compounds sensitize the pituitary to GnRH through mechanisms not involving the oestrogen receptor complex (nongenomic).

Changes in pituitary sensitivity to GnRH in estrogen-treated post-menopausal women: evidence that gonadotrophin surge attenuating factor plays a physiological role.

BACKGROUND: The purpose of this study was to investigate changes in pituitary response to GnRH in post-menopausal women during substitution treatment with exogenous estrogen and progesterone. METHODS: Seven healthy post-menopausal women (group 1) were treated with various doses of E2 valerate for 43 days, so as the serum concentrations of E2 mimicked those of a follicular (FP-1), a luteal (LP) and a second follicular (FP-2) phase. During the LP, progesterone was also administered. The 30 min response of LH (DeltaLH) and FSH (DeltaFSH) to GnRH (10 microg i.v.) (pituitary sensitivity) was investigated every 24 h in group 1 and also in seven normally cycling women (group 2) during a spontaneous (control) follicular phase (FP). Based on the hormone profiles, day 32 in group 1 (FP-2) corresponded to day 2 in the spontaneous FP of group 2. RESULTS: Basal FSH concentrations were significantly higher in FP-2 than in the control FP (P < 0.05), while basal LH concentrations were similar in the two phases with higher values in FP-2 towards the end of the experiment (corresponding to days 10 and 11, P < 0.05). However, an LH surge was seen only in the control FP. DeltaFSH values remained stable in both phases and increased only in the control FP on days 12 and 13. DeltaLH values remained stable in the control FP and only increased on days 12 (P < 0.05) and 13 (P < 0.05), but in FP-2, DeltaLH values increased earlier (corresponding to day 7, P < 0.05). CONCLUSIONS: The present study demonstrates for the first time that in the absence of ovarian function, follicular phase E2 concentrations sensitize the pituitary to GnRH at an earlier stage (corresponding to the midfollicular phase) than in the normal menstrual cycle (late follicular phase). It is suggested that during the early to midfollicular phase the ovaries produce a gonadotrophin surge attenuating factor (GnSAF) that antagonizes the pituitary-sensitizing effect of E2 to GnRH.