Menstrual Cycle In Normal Women Research Articles

SAT446 Association of Polychlorinated Biphenyls With the Hormonal Parameters of the Normal Menstrual Cycle May Contribute to Unexplained Infertility

Abstract Disclosure: A.E. Butler: None. E. Brennan: None. T. Sathyapalan: None. S.L. Atkin: None. Introduction: Polychlorinated biphenyls (PCBs) are organic lipophilic pollutants that accumulate through the diet and increase with age and obesity. Previous research has linked PCBs with menstrual function; therefore, this study was undertaken to look at the association of PCBs with parameters of menstrual function at day 21 of the menstrual cycle in a group of women who were undergoing in vitro fertilization (IVF). Methods: 29 Caucasian women from a UK academic center aged 32.9±4.4 years, with body mass index BMI 25.4±3.6 kg/m2, who were undergoing in vitro fertilization were recruited. Five of the women had unexplained infertility and the remainder (n=24) had male factor infertility or tubal problems. Blood was withdrawn at day 21 of their menstrual cycle, at the time of mock embryo transfer. PCBs were measured using high resolution gas chromatography. Results: Only PCB118, PCB153, PCB138 and PCB180 were detected. PCB153, PCB138, PCB180 inversely correlated with estradiol (p<0.05). PCB 118 and PCB138 inversely correlated with FSH (p<0.05). PCB118, PCB153, PCB138 and PCB180 inversely correlated with LH (p<0.05, p<0.01, p<0.01 and p<0.01, respectively). No correlation was seen between PCBs and progesterone. Women with unexplained infertility showed higher levels of PCB118, PCB153, PCB138 and PCB180 (p<0.05) compared to those with male factor infertility though other hormonal parameters did not differ other than FSH that was lower in the unexplained group (p=0.01). Conclusion: These data are in accord with an effect of PCBs on the menstrual cycle in normal women and may be involved in the mechanism of unexplained infertility. Presentation Date: Saturday, June 17, 2023

Characterisation of peri-implantation endometrial Treg and identification of an altered phenotype in recurrent pregnancy loss

Recurrent Pregnancy Loss (RPL) affects 2–4% of couples, and with increasing numbers of pregnancy losses the risk of miscarrying a euploid pregnancy is increased, suggesting RPL is a pathology distinct from sporadic miscarriage that is due largely to lethal embryonic aneuploidy. There are a number of conditions associated with RPL including unspecified “immune” pathologies; one of the strongest candidates for dysregulation remains T regulatory cells as depletion in the very early stages of pregnancy in mice leads to pregnancy loss. Human endometrial Treg and conventional CD4T cells were isolated during the peri-implantation period of the menstrual cycle in normal women. We identified an endometrial Treg transcriptomic signature and validated an enhanced regulatory phenotype compared to peripheral blood Treg. Parous women had an altered endometrial Treg transcriptome compared to nulliparity, indicating acquired immune memory of pregnancy within the Treg population, by comparison endometrial conventional CD4T cells were not altered. We compared primary and secondary RPL to nulliparous or parous controls respectively. Both RPL subgroups displayed differentially expressed Treg gene transcriptomes compared to controls. We found increased cell surface S1PR1 and decreased TIGIT protein expression by Treg in primary RPL, confirming the presence of altered Treg in the peri-implantation RPL endometrium.

Von Willebrand disease and other bleeding disorders in women: consensus on diagnosis and management from an international expert panel

Reproductive tract bleeding in women is a naturally occurring event during menstruation and childbirth. In women with menorrhagia, however, congenital bleeding disorders historically have been underdiagnosed. This consensus is intended to allow physicians to better recognize bleeding disorders as a cause of menorrhagia and consequently offer effective disease-specific therapies.

Acylation-stimulating protein increases and correlates with increased progesterone levels during the luteal phase of the menstrual cycle

The menstrual cycle represents a continuous state of change in terms of female sex steroid environment. Progesterone is linked to increased fat storage while estrogen exerts anti-lipogenic effects. This study investigated variations in the potent lipogenic factor acylation-stimulating protein (ASP), and examined its association with hormonal and lipid profile alterations across the menstrual cycle. Nineteen non-obese women with regular menstrual cycles were investigated in a longitudinal study during the follicular, ovulatory, and mid-luteal phases (ML) of the cycle. Fasting ASP, LH, FSH, progesterone, estradiol, insulin, lipid profile, and apoproteins were evaluated during different phases of the cycle. ASP levels changed significantly throughout the menstrual cycle (K-related Friedman test: P=0.013). Interestingly, these changes coincide with variations in progesterone levels across the cycle as no significant change in the ASP levels was seen across the follicular phases of the cycle, followed by a significant increase in the ovulatory phase, which continued to elevate toward the ML. The ASP levels correlated positively with the progesterone levels normally elevated in the ML. No significant correlation was seen between ASP and estrogen or any other measured female hormone. Multiple regression analysis including all measured parameters and body mass index showed that progesterone was the only significant predictor of the ASP levels. Our findings suggest that during the menstrual cycle of normal women, the ASP levels coincidentally fluctuate with the progesterone levels, possibly reflecting cooperation between them in fat storage enhancement.

Transcallosal inhibition across the menstrual cycle: A TMS study

Objective To determine if there are steroid-dependent changes in transcallosal transfer during the menstrual cycle in normal women. Methods We tested 13 normally cycling women during the menstrual, follicular and midluteal phases. Blood levels of estradiol (E) and progesterone (P) were determined by radioimmunoassay. Ipsilateral tonic voluntary muscle activity suppression, called ipsilateral silent period (iSP), was evoked by applying transcranial magnetic stimulation (TMS) over the left motor cortex and by measuring the EMG of the ipsilateral first dorsal interosseus (FDI) muscle. Both iSP-duration and transcallosal conduction times were measured and related to cycle phase and steroid levels. Results Duration of iSPs varied over the cycle with largest differences between follicular and midluteal phases. During the midluteal phase high levels of P were significantly related to short iSPs. This relation also applied to E levels and iSPs during the follicular phase. Conclusions Our study shows for the first time that the transcallosal transfer is modulated by E and P and changes over the menstrual cycle. Significance It is suggested that gonadal steroid hormones affect the interhemispheric interaction and change the functional cerebral organization sex dependently via its neuromodulatory properties on GABAergic and glutamatergic neurons.

Cyr61, a Member of the CCN Family, is Up-Regulated in Endometrium From Women With Polycystic Ovarian Syndrome Compared to Normal Controls

ObjectiveTo evaluate the temporal and spatial distibution of Cyr61 in normal endometrium throughout the menstrual cycle and compare its expression in endometrium from women with polycystic ovarian syndrome (PCOS). We also studied the regulation of Cyr61 in the well-differentiated, hormone-responsive endometrial cell line, ECC1.DesignThis is a retrospective study on 21 endometrial samples from the proliferative and secretory phase of the menstrual cycle in normal women and women with hyperandrogenism and PCOS. Regulation of Cyr61 was performed in vitro using the well-differentiated endometrial cell line, ECC1.Materials and methodsWestern blot analysis of Cyr61 was performed on protein lysates of untreated ECC1 cells and cells treated for 6 and 12 hours with diethylstilbestrol (DES; 10-8M) in the presence or absence of the anti-estrogen ICI 182,780. Immunohistochemistry on endometrial samples and western blot analysis was performed using the specific Cyr61 polyclonal antibody (generously provided by Dr. Lester Lau, UIC, Chicago, IL). Additional staining was performed for the estrogen receptor alpha (ERa) and a marker of cell proliferation, Ki67. Twenty-one endometrial biopsies were obtained from both fertile and PCOS women during the menstrual cycle. Statistical analysis was performed using ANOVA with Bonferroni correction with significance at the 95% confidence interval (p < 0.05).ResultsConclusionThe Cyr61 protein is a sensitive marker of estrogen activity and is significantly increased in the endometrium of women with PCOS in both the proliferative and secretory phase. Further studies will be required to investigate the mechanism for this over-expression of Cyr61, but evidence suggests that failure of down-regulation of estrogen receptors in the secretory phase may play a role. ObjectiveTo evaluate the temporal and spatial distibution of Cyr61 in normal endometrium throughout the menstrual cycle and compare its expression in endometrium from women with polycystic ovarian syndrome (PCOS). We also studied the regulation of Cyr61 in the well-differentiated, hormone-responsive endometrial cell line, ECC1. To evaluate the temporal and spatial distibution of Cyr61 in normal endometrium throughout the menstrual cycle and compare its expression in endometrium from women with polycystic ovarian syndrome (PCOS). We also studied the regulation of Cyr61 in the well-differentiated, hormone-responsive endometrial cell line, ECC1. DesignThis is a retrospective study on 21 endometrial samples from the proliferative and secretory phase of the menstrual cycle in normal women and women with hyperandrogenism and PCOS. Regulation of Cyr61 was performed in vitro using the well-differentiated endometrial cell line, ECC1. This is a retrospective study on 21 endometrial samples from the proliferative and secretory phase of the menstrual cycle in normal women and women with hyperandrogenism and PCOS. Regulation of Cyr61 was performed in vitro using the well-differentiated endometrial cell line, ECC1. Materials and methodsWestern blot analysis of Cyr61 was performed on protein lysates of untreated ECC1 cells and cells treated for 6 and 12 hours with diethylstilbestrol (DES; 10-8M) in the presence or absence of the anti-estrogen ICI 182,780. Immunohistochemistry on endometrial samples and western blot analysis was performed using the specific Cyr61 polyclonal antibody (generously provided by Dr. Lester Lau, UIC, Chicago, IL). Additional staining was performed for the estrogen receptor alpha (ERa) and a marker of cell proliferation, Ki67. Twenty-one endometrial biopsies were obtained from both fertile and PCOS women during the menstrual cycle. Statistical analysis was performed using ANOVA with Bonferroni correction with significance at the 95% confidence interval (p < 0.05). Western blot analysis of Cyr61 was performed on protein lysates of untreated ECC1 cells and cells treated for 6 and 12 hours with diethylstilbestrol (DES; 10-8M) in the presence or absence of the anti-estrogen ICI 182,780. Immunohistochemistry on endometrial samples and western blot analysis was performed using the specific Cyr61 polyclonal antibody (generously provided by Dr. Lester Lau, UIC, Chicago, IL). Additional staining was performed for the estrogen receptor alpha (ERa) and a marker of cell proliferation, Ki67. Twenty-one endometrial biopsies were obtained from both fertile and PCOS women during the menstrual cycle. Statistical analysis was performed using ANOVA with Bonferroni correction with significance at the 95% confidence interval (p < 0.05). Results ConclusionThe Cyr61 protein is a sensitive marker of estrogen activity and is significantly increased in the endometrium of women with PCOS in both the proliferative and secretory phase. Further studies will be required to investigate the mechanism for this over-expression of Cyr61, but evidence suggests that failure of down-regulation of estrogen receptors in the secretory phase may play a role. The Cyr61 protein is a sensitive marker of estrogen activity and is significantly increased in the endometrium of women with PCOS in both the proliferative and secretory phase. Further studies will be required to investigate the mechanism for this over-expression of Cyr61, but evidence suggests that failure of down-regulation of estrogen receptors in the secretory phase may play a role.

Women and insomnia

The occurrence of insomnia in women is influenced in great part by the complex hormonal cycles they undergo. Patterns of insomnia in younger women may be physiologically different on a hormonal basis from those found in older women. Although significant objective sleep disturbances have been difficult to demonstrate across the menstrual cycle in normal women, the International Classification of Sleep Disorders (ICSD) includes premenstrual insomnia and premenstrual hypersomnia as sleep disorders within the category of menstrual-associated sleep disorder. On the other hand, during pregnancy and after childbirth, profound fluctuations in steroid and hypothalamic-pituitary-adrenal axis-related hormones produce significant physiological changes, including sleep disruption. During the menopausal transition, significant sleep disruptions are provoked by sleep-disordered breathing, vasomotor disturbance, and mood disorders. Regardless of age, women with chronic insomnia are at higher risk for developing or sustaining depression. Thoughtful management approaches must consider known relationships between menstrual or menopausal status and various sleep disorders, and should rely on pharmacologic, nonpharmacologic, or a combination of treatments to achieve successful relief from insomnia. The off-label, first-line use of antidepressants for treating insomnia in the absence of depression is now considered debatable. The long-term efficacy and safety of the newer benzodiazepine receptor agonists (BZRAs) for insomnia, whether taken nightly or episodically, are supported by existing clinical experience. US Food and Drug Administration guidelines limiting the use of hypnotics to only a few weeks predate the newer generation BZRAs, and, as such, the guidelines may no longer be truly appropriate for these new agents.

Left ventricular function and autonomic nervous system balance during two different stages of the menstrual cycle

We studied the left ventricular function and cardiac autonomic nervous system balance variations during two different stages of the menstrual cycle. These two variables, as well as plasmatic estradiol and progesterone concentrations, were measured in a drug-free state in 20 women (29±6 year-old) with regular menstrual periods. A clinical evaluation, an echo-Doppler and a Valsalva manoeuvre were performed in all the patients on the third day of their menstrual cycle (follicular phase) and three days prior to their next menstrual cycle (luteinizing phase). When comparing the results obtained in these two phases, a statistically significant increase was put forward in plasmatic estradiol (50.6±24 vs. 127.3±52.8 pg/ml) and progesterone (0.37±0.42 vs. 11.92±10.8 ng/ml) concentrations, Valsalva index (1.55±0.22 vs. 1.67±0.33; P=0.044) and E/ A mitral wave ratio (1.63±0.36 vs.1.75±0.35, P=0.02). The right and left atrial volumes, left ventricular volumes and ejection fraction were similar in the two menstrual phases studied. We conclude that the autonomic nervous system balance and the left ventricular diastolic function suffer significant changes during the luteinizing phase of the menstrual cycle in normal women.

Alterations in the insulin-like growth factor system during the menstrual cycle in normal women

Objectives: To evaluate the effects of endogenous estrogens and progestins on the IGF-system during the normal menstrual cycle in healthy premenopausal women not using contraceptive drugs. Methods: Nine women had fasting blood samples obtained at 2–3 days intervals during a 5 week study period. Plasma levels of IGF-I, IGF-II, IGFBP-1, IGFBP-3, estradiol and progesterone were measured by radioimmunoassay (RIA) in each sample. IGFBP-3 was also evaluated by Western ligand blot (WLB) and immunoblot. Any differences between the menstrual phase (defined as day 1–5), follicular and luteal phases (separation based on plasma estradiol and progesterone values) were evaluated by the Friedman test. Results: A small but significant difference in plasma levels of IGF-I ( P<0.01) and IGFBP-3 ( P<0.05) measured by RIA between the three phases were seen with the highest levels found during the follicular phase. No change in plasma levels of IGFBP-1 and IGF-II was found and immunoblots did not reveal any alteration in the ratio of fragmented to intact IGFBP-3 during the menstrual cycle. A positive correlation between plasma levels of IGF-I and estradiol was seen in 8 out of 9 patients ( P=0.012). Conclusions: The finding of a slight but significant higher level of plasma IGF-I in the follicular and luteal phases compared with the menstrual phase suggests plasma estradiol may influence the level of this growth factor. This hypothesis is further supported by the finding of a correlation between plasma levels of IGF-I and estradiol but not progesterone in individual patients at different times during the menstrual cycle.

Cyclical variation of plasma lipids, apolipoproteins, and lipoprotein(a) during menstrual cycle of normal women.

We report herein the effects of cyclical variations of endogenous sex steroids during the menstrual cycle on plasma lipids and apolipoproteins (apo) in normal women. We examined 16 normal women (age range 25-36 yr) with normal menstrual cycles of 28-31 days. The study covered the period from the 1st day of a menstrual phase (basal) until the 1st day of the following menstrual phase. During the study all women maintained a normolipidic diet (30% fat). Plasma total cholesterol and low-density-lipoprotein cholesterol were significantly higher than basal in the preovulatory phase until progesterone started to increase in the postovulatory phase [day +8 from luteinizing hormone (LH) surge]. High-density-lipoprotein cholesterol was significantly higher than basal from day -1 to the day after LH surge, whereas plasma apoAI levels were significantly higher from day -8 to day +8 (from LH surge). Plasma apo(a) increased significantly during the luteal phase in four women characterized by a single S4 band and lower basal plasma levels of apo(a). Our results indicate that endogenous female sex steroids have significant effects on the circulating levels of plasma lipids and apolipoproteins, including apo(a). More work needs to be done to elucidate the significance of the observed apo(a) changes, and the different phases of the menstrual cycle must be taken into account when evaluating the lipidic risk profile in premenopausal women.

Body image changes over the menstrual cycle in normal women.

Changes in body image across the menstrual cycle and the relationship between these changes and menstrual distress were investigated in an effort to identify determinants of body dissatisfaction. Twenty-six normally cycling women between 18-40 years of age and 90-115% of ideal body weight, with no history of an eating disorder, completed a series of body image measures and a measure of menstrual distress during three menstrual cycle phases: perimenstrual, follicular, and luteal. These phases were identified with serum levels of ovarian hormones and basal body temperature. Results indicated that body dissatisfaction as measured by the number of body-related negative thoughts and anxiety about appearance was significantly highest during the perimenstrual phase. In contrast, measures of body size perception remained stable. Several somatosensory and psychological symptoms of menstrual distress were significantly associated with body dissatisfaction during the perimenstrual phase including, water retention, autonomic reactivity, control, negative affect, and impaired concentration. This association of body dissatisfaction and menstrual distress strongly suggests that menstrual cycle changes play a significant role in body image.

Circulating Nitrite/Nitrate Levels Increase with Follicular Development: Indirect Evidence for Estradiol-Mediated NO Release

Ovarian dysfunction as well as impaired release of endothelium-derived nitric oxide (NO) is associated with increased incidence of cardiovascular disease in postmenopausal women. Estrogen replacement therapy in postmenopausal women has a cardioprotective effect. Hence, using follicular development (FD) phase of the menstrual cycle of normal women (n = 7) and of patients undergoing in vitro fertilization (n = 16), we tested whether ovarian/sex hormones modulate NO-release. Levels of nitrite/nitrate (stable metabolites of NO), 17β-estradiol (E), progesterone (P), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured in serum collected during FD-phase. Serum nitrite/nitrate levels increased (p < .01) with the normal, as well as hormonally-induced FD and correlated with increases in serum E levels (r2 = 0.67; p < .01), but not with P, FSH and LH (p > .05). Post-ovulatory increase in P and LH levels decreased serum nitrite/nitrate levels (p < .05), even in presence of high E levels. In conclusion, nitrite/nitrate increase with follicular development, an effect that is potentially mediated by E induced NO release.

Decreased release of gonadotropin-releasing hormone during the preovulatory midcycle luteinizing hormone surge in normal women.

To investigate the contribution of hypothalamic gonadotropin-releasing hormone (GnRH) secretion to the midcycle gonadotropin surge in the human, the response of luteinizing hormone (LH) to competitive GnRH receptor blockade achieved by administration of a range of doses of a pure GnRH antagonist was used to provide a semiquantitative estimate of endogenous GnRH secretion. The LH response to 5, 15, 50, and 150 micrograms/kg s.c. of the NAL-GLU GnRH antagonist ([Ac-D-2Nal1,D-4ClPhe2,-D-Pal3,Arg5,D-4-p-met hoxybenzoyl-2-aminobutyric acid6,D-Ala10]GnRH, where 2Nal is 2-naphthylalanine, 4ClPhe is 4-chlorophenylalanine, and 3Pal is 3-pyridylalanine) was measured in normal women in the early and late follicular phases of the menstrual cycle, at the time of the midcycle LH surge and in the early luteal phase. LH decreased in a dose-response fashion after administration of the GnRH antagonist in all cycle phases (P < 0.0001). When this suppression was expressed as maximum percent inhibition, there was no difference in response during the early and late follicular and early luteal phases. However, at the midcycle surge, there was a leftward shift of the dose-response curve with significantly greater suppression of LH at the lower antagonist doses in comparison to the other cycle phases (P < 0.005), but no difference at the highest dose. Thus, we draw the following conclusions. (i) There is a consistently greater degree of LH inhibition by GnRH antagonism at the midcycle surge at submaximal degrees of GnRH receptor blockade than at other phases of the menstrual cycle in normal women. (ii) This leftward shift of the dose-response relationship to GnRH receptor blockade suggests that the overall amount of GnRH secreted at the midcycle surge is less than at other cycle stages. (iii) These data confirm the importance of pituitary augmentation of the GnRH signal at the time of the midcycle gonadotropin surge in the human.

Lack of impact of pharmacological growth hormone administration on circulating levels of reproductive hormones during the menstrual cycle in normal women

To evaluate the effects of pharmacological growth hormone (GH) administration on the secretion of pituitary and gonadal hormones during the menstrual cycle in normal women. Randomized, double-blind, placebo-controlled crossover design. Six normally menstruating, healthy women, 22 to 24 years of age and with a normal body mass index. Each participant was treated with placebo and growth hormone (12 IU/d) during two different 14-day periods, separated by a 6-week washout period. Serum insulin-like growth factor I (IGF-I), estradiol, progesterone, follicle-stimulating hormone, and luteinizing hormone. Administration of GH for 14 days resulted in a significant increase in serum IGF-I, whereas no changes occurred in gonadotropin or sex steroid response. Growth hormone treatment during the first 14 days of menstrual cycle in normal women does not affect gonadotropin or sex steroid patterns.

Renal sodium retention does not occur during the luteal phase of the menstrual cycle in normal women.

To determine whether weight gain due to renal sodium and water retention occurs in the luteal phase of the normal menstrual cycle. Prospective observational study. Research laboratory installed with modified spa bath. Ten normal healthy women. Each subject underwent two experiments, one in each phase of the menstrual cycle, involving 3 h head-out water immersion and a pre- and post immersion control hour. 25 ml blood samples were obtained every hour before, during and after water immersion. Renal and hormonal responses to water immersion during the luteal and proliferative phases of the cycle. There was no change in weight, creatinine clearance, basal sodium excretion or plasma atrial natriuretic peptide between the two phases of the cycle. There was a significant rise in basal progesterone, plasma aldosterone and plasma renin activity in the luteal phase of the ovulatory cycles. Renal and hormonal responses to immersion including sodium and calcium excretion, elevation of atrial natriuretic peptide (ANP) and suppression of plasma aldosterone and plasma renin activity were identical in the two phases of the menstrual cycle. We found no evidence to support the hypothesis that renal sodium and water retention occurs in the luteal phase of the normal menstrual cycle.

The effect of smoking on serum progesterone, estradiol, and luteinizing hormone levels over a menstrual cycle in normal women

Since smoking has been shown to affect serum progesterone and estradiol levels in postmenopausal women, we evaluated the levels of these hormones and luteinizing hormone (LH) over an entire menstrual cycle (17 points) in eight healthy nonsmokers and eight healthy smokers. The total length of the cycle and the lengths of the follicular and luteal phases did not differ between the groups. There was no difference in estradiol, progesterone, or LH levels during the periovulatory and luteal phases. Follicular-phase serum progesterone, which had a level 37% higher in smokers, showed a plateau in both groups (28.3 ± 5.7 ng/dl versus 20.7 ± 5.7; P < 0.0001). Follicular-phase serum estradiol showed a rising curve in both groups. The mean value in smokers was slightly higher than that in nonsmokers (107 pg/ml versus 95; P ~ 0.05); during the early part of the follicular phase, prior to the rapid preovulatory increase, the difference was greater (23%) and of higher statistical significance (80 pg/ml versus 65; P < 0.001). The follicular-phase LH levels of smokers were skewed downward from the levels in nonsmokers, presumably by negative feedback from the elevated estradiol and progesterone levels; the difference was significant (P < 0.001). The elevations of serum progesterone and estradiol in smokers probably represent activation of adrenocortical secretion by smoking. The greater and more clear-cut rise of progesterone than of estradiol is probably due to the fact that essentially all of the follicular-phase serum progesterone is secreted by the adrenal, while only part of the follicular-phase serum estradiol comes from the adrenal (via androstenedione and estrone). (Steroids 55:507–511, 1990)

Luteal Phase Deficiency: Abnormal Gonadotropin and Progesterone Secretion Patterns*

Luteal phase deficiency (LPD) is a reproductive disorder associated with infertility and spontaneous abortion. This study was undertaken to determine whether LPD might be related to an abnormal pattern of gonadotropin secretion. We tested this hypothesis by evaluating the pattern of pulsatile LH secretion in both the follicular and luteal phases of the menstrual cycle in normal women (n = 21) and women with LPD (n = 20), which was diagnosed on the basis of two out of phase endometrial biopsies. In addition, we sought to determine whether changes in progesterone (P) pulse patterns could account for the decrease in average serum P levels in women with LPD. To this end, we examined the pulse patterns of P and compared these patterns between normal women and those with LPD. Frequent blood sampling was performed in both groups to determine their respective hormone secretion patterns. In the follicular phase, blood samples were obtained every 10 min for 12 h; in the luteal phase the samples were obtained every 10 min for 12 h; in the luteal LH, FSH, and P were assayed in each sample. Pulse detection was performed by an adaptive threshold method of pulse analysis. The LH pulse frequency was significantly higher in the women with LPD than in the normal women in the early follicular phase [P less than 0.05; LPD, 12.8 +/- 1.4 (+/- SE); normal, 8.2 +/- 0.7 pulses/12 h]. LH pulse frequency was similar in the early and late follicular phases in the women with LPD, whereas it was higher in the late follicular phase in normal women. Mean serum FSH levels were not different between groups in both the early and late follicular phases. In the luteal phase the P pulse amplitude and mean serum P level were significantly lower in the LPD group than in the normal women (P less than 0.01). We conclude that 1) a too rapid LH pulse pattern in the early follicular phase may lead to inadequate LH support of the corpus luteum and become manifest as LPD; 2) the mechanism for inadequate P secretion in LPD is decreased P pulse amplitude; 3) the finding of similar serum FSH levels in the two groups in both the early and late follicular phases did not support compromised folliculogenesis as an etiological factor for LPD.

Statistical evaluation of coincident prolactin and luteinizing hormone pulses during the normal menstrual cycle.

The purpose of this work was 2-fold. First, we sought to develop statistical criteria by which it could be established that the coincident occurrence of pulses of two different hormones exceeds that which would occur by chance alone, thereby suggesting that secretion of the two hormones is either coupled or controlled from a single source generator. Using computer simulations of uncoupled pulse generators operating at different frequencies, we were able to derive the appropriate statistical criteria and to apply them to achieve our second objective, to determine whether the occasional coincidence of plasma LH and serum PRL pulses that occurs throughout the menstrual cycle in normal women exceeds that which would happen by chance. The results of the computer simulations indicated that pulses emanating from two completely independent oscillators will occur coincidently at a predictable rate, despite the fact that the generator sources are not coupled; moreover, the rate of coincidence is increased when the pulse frequency of one of the source generators is increased. Using this knowledge and the statistical criteria we derived, we analyzed the coincidence of LH and PRL pulses in five normal women during their early follicular, late follicular, and midluteal phases and in another five women during their late luteal phase. We found that the number of PRL pulses that occurred coincidently with LH pulses consistently exceeded that which would be predicted if the two pulse generators were operating completely independently of one another; however, only during the late follicular and late luteal phases was the coincidence level between LH and PRL pulses sufficiently high in a sufficient number of women to conclude that there was coupling between the pulse sources. These studies suggest, first, that stringent and rigorous statistical criteria must be applied to the analysis of spontaneously coincident secretory phenomena before it can be deduced that two pulse generators are indeed coupled, and second, that the pulse generators governing the secretion of PRL and LH are probably coupled, at least during certain phases of the menstrual cycle.

Use of Immunocytochemistry of Progesterone and Estrogen Receptors for Endometrial Dating

Endometrial progesterone and estrogen receptors were studied by immunocytochemistry using monoclonal antibodies during the menstrual cycle in normal women. We initially compared immunocytochemical staining of progesterone and estradiol receptors on endometrial fragments obtained by either aspiration or endometrial biopsy and found that immunocytochemistry could be performed easily on tissue obtained in either way. The immunocytochemical studies showed that the concentration and distribution of receptors changed markedly during the normal menstrual cycle. These changes were distributed in three characteristic phases. During phase I, corresponding to the midfollicular period (days 7-8), a small proportion (25%) of stromal and glandular cells stained positively for the progesterone receptor, whereas estrogen receptor staining was more intense and more frequent (50% of cells). Phase II, which included both the late follicular and early luteal periods (days 9-19), was characterized by a marked staining of progesterone receptors in the majority of glandular cells (75%) and somewhat less abundant and less frequent staining in stromal cells (50%). Estrogen receptor staining was present in about half of the glandular and stromal cells. Phase III, the mid- and late luteal period (days 21-27), was characterized by the disappearance of estrogen and progesterone receptor staining in glandular cells, although faint staining for both receptors was found in stromal cells. These variations in progesterone receptor staining are potentially useful for determining the effect of progesterone on endometrial maturation.

Insulin action does not change during the menstrual cycle in normal women.

Normal women have alterations in carbohydrate metabolism during pregnancy and when taking oral contraceptives, and clinical observations suggest that diabetic women need more insulin during menstruation. We, therefore, studied insulin action in normal women during the menstrual cycle in the follicular, luteal, and menstrual phases. Glucose tolerance was similar at all three times. Specific insulin receptor binding to monocytes did not change during the menstrual cycle. Euglycemic insulin clamp studies at four different insulin infusion rates (15, 40, 120, and 240 mU/M2 X min) showed no differences in insulin sensitivity or responsiveness throughout the menstrual cycle, and hepatic glucose output did not change. These studies suggest that if insulin action is impaired during menstruation in diabetic women it is because of factors that are not detected in normal women.