Factors related to declining luteal function in women during the menopausal transition.

CONTEXT: Reproductive hormones are incompletely characterized during the menopause transition (MT). HYPOTHESIS: Increased anovulation and decreased progesterone accompany progress through the MT. DESIGN: The Daily Hormone Study (DHS) of the Study of Women's Health Across the Nation (SWAN) included 848 women aged 43-53 yr at baseline who collected daily urine for one cycle or up to 50 d annually for 3 yr. MAIN OUTCOME MEASURES: LH, FSH, estrone conjugates, and pregnanediol glucuronide levels were assessed. Cycles were classified by presumed luteal (ovulatory) status and bleeding. Hormones were related to time in study, age, menopausal status, and selected variables. RESULTS: Ovulatory-appearing cycles declined from 80.9% at baseline to 64.7% by the third assessment (H3). Cycles presumed anovulatory and not ending with bleeding by 50 d (anovulatory/nonbleeding) increased from 8.4 to 24% by H3 and were associated with progress to early perimenopause [odds ratio (OR) = 2.66; confidence interval (CI) = 1.17-6.04] or late perimenopause (OR = 56.21; CI = 18.79-168.12; P < 0.0001), African-American ethnicity (OR = 1.91; CI = 1.06-3.43), and less than high school education (OR = 3.51; CI = 1.62-7.62). Anovulatory cycles ending with bleeding remained at about 10% from baseline to H3; compared with ovulatory cycles, they were associated with obesity (OR = 4.68; CI = 1.33-16.52) and more than high school education (OR = 2.12; CI = 1.22-3.69; P = 0.02). Serum estradiol in both the highest and lowest categories was associated with anovulatory/nonbleeding collections. Pregnanediol glucuronide decreased 6.6% for each year on study. Insulin sensitivity measures did not relate strongly to menstrual cycle hormones. CONCLUSIONS: Anovulation without bleeding represents progression of the MT. A small but detectable decrease in luteal progesterone excretion occurs as women progress through the MT.

A population-based longitudinal study of cognitive functioning in the menopausal transition.

BACKGROUND: No longitudinal studies have tracked cognitive performance through the menopausal transition and thus the impact of the transition on cognition, independent of aging, is not known. The authors hypothesized that a decline in cognitive functioning occurs as women progress through the menopausal transition, independent of age, educational level, family income, ethnicity, and baseline self-perceived health. METHOD: The authors began a population-based, longitudinal study in January 1996 with yearly follow-up interviews. This report includes follow-up through November 2001. The authors randomly selected African American and white women from a census of two contiguous Chicago communities. After screening for eligibility (age 42 to 52 years, premenopausal or early perimenopausal, no exogenous hormone use in the past 3 months, and no hysterectomy), 868 agreed to participate. Women who became pregnant, had a hysterectomy, or began using hormones were censored from that time onward. This study reports on 803 women for whom cognitive assessments were available. The authors assessed working memory (Digit Span Backward) and perceptual speed (Symbol Digit Modalities Test). RESULTS: Contrary to the hypothesis, the authors found small but significant increases over time during the premenopausal and perimenopausal phases. This trend was not accounted for by chronological age, education, family income, ethnicity, or baseline self-perceived health. CONCLUSIONS: Transition through menopause is not accompanied by a decline in working memory and perceptual speed.

Premature menopause in a multi-ethnic population study of the menopause transition.

BACKGROUND: Premature menopause, also termed premature ovarian failure (POF), is characterized by cessation of menstruation before the age of 40 years. Little information is available on the general prevalence of POF or on the prevalence by ethnic group. There is also a lack of information on the association of POF with health indicators. METHODS: A cross-sectional survey of women aged 40-55 years was conducted at seven sites in the USA to determine eligibility for a community-based, multi-ethnic longitudinal study of the peri-menopause (The Study of Women Across the Nation, SWAN). Interview data were used to (i). determine the prevalence of self-reported POF overall and by ethnic group, and (ii). assess the association of POF with selected self-reported variables related to health. Cases of POF included only women with no discernible cause for POF. RESULTS: POF was reported by 1.1% (126/11 652) of women. By ethnicity, 1.0% (95% CI, 0.7-1.4) of Caucasian, 1.4% (95% CI, 1.0-2.1) of African American, 1.4% (95% CI, 0.8-2.5) of Hispanic, 0.5% (95% CI, 0.1-1.9) of Chinese and 0.1% (95% CI, 0.02-1.1) of Japanese women experienced POF. The differences in frequency across ethnic groups were statistically significant (P = 0.01). Only Caucasian, African American and Hispanic women were included in further analyses since too few Asian women had POF. In a multivariate model, POF was independently associated with osteoporosis, female hormone use (excluding oral contraceptives), higher body mass index (BMI) and current smoking after adjustment for education level, ability to pay for basics, site and age at interview. In Caucasian women, use of female hormones, osteoporosis, severe disability and smoking were significantly associated with POF. In contrast, POF in African American women was associated with higher BMI and female hormone use, but not osteoporosis. CONCLUSIONS: The prevalence of POF appears to vary by ethnicity. Health factors associated with POF also vary by ethnicity but because of the cross-sectional study design, it is not possible to determine cause and effect relationships. Health risks of POF would benefit from further study.

Evidence for different aetiologies of low estradiol response to FSH: age-related accelerated luteinization of follicles or presence of ovarian autoantibodies.

BACKGROUND: We found granulosa cells of low responders (LR) expressed more LH receptors, suggesting that follicles were more luteinized than normal responders (NR). The objectives were to test the hypothesis that follicles of LR were more luteinized than follicles of NR, and to determine if LR with (LR+) and without (LR-) ovarian antibodies differed. METHODS: Hormone levels and ovarian autoantibodies (OVAB) were measured in follicular fluid from mature follicles (>17 mm), and in serum obtained on the day of oocyte retrieval during controlled ovarian stimulation. The gonadotrophin response was defined as a ratio of peak estradiol/number of FSH ampoules. RESULTS: NR (32.5 +/- 4.6 years; n = 11) were similar in age to LR+ (33.4 +/- 4.2 years; n = 9) and were younger than LR- (37.1 +/- 3.8 years; n = 12) (P = 0.03). Likewise, dehydroepiandrosterone sulphate was lower in LR- compared with LR+ or NR (P < 0.01). FSH, progesterone, inhibin-A and vascular endothelial growth factor levels were higher in follicular fluid of LR than NR. LR- and LR+ differed. For example, the follicular fluid progesterone/estradiol ratio was similar in NR (11.1 +/- 8.9) and LR+ (9.8 +/- 6.6) but was lower than LR- (22.9 +/- 19.6) (P = 0.05). Serum hormone levels did not reflect follicular fluid hormone profiles. CONCLUSIONS: In the absence of ovarian antibodies, low responses are associated with higher age and accelerated luteinization of mature follicles, rather than diminished responsiveness. Ovarian antibody may be an additional tool to predict and individualize treatment regimens in poor responders.

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

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

Polycystic ovary syndrome and ovarian autoimmunity--assessment of ovarian antibodies by EIA.

There are conflicting reports of an association of ovarian antibodies, detected by immunofluorescence, with polycystic ovary syndrome (PCOS). The objective of this study was to evaluate the association of ovarian autoimmunity with PCOS. A validated immunoassay for ovarian antibodies was used to assess serum from women with PCOS and with menopause and normal cycling women as controls. The frequency of ovarian antibodies was similar (25%) among the controls and PCOS. Thus, unlike the association of ovarian antibodies detected with this test in patients with unexplained infertility and premature menopause, the prevalence of ovarian antibody in patients with PCOS is not significantly different to controls.

Evidence of gonadal and gonadotropin antibodies in women with a suboptimal ovarian response to exogenous gonadotropin.

Failure to respond to human menopausal gonadotropin (hMG) with adequate ovarian stimulation is associated with a poor prognosis in subsequent cycles in women participating in an in vitro fertilization/embryo transfer program. Sera from 26 menstruating women (mean age 38 +/- 4.3 years) identified as "low responders" with either tubal or male factor infertility, mean baseline FSH values of 11 mIU/mL, and peak serum estradiol levels lower than 300 pg/mL were assessed for specific antibodies to human ovary and gonadotropins. Twenty-five infertile women with tubal or male factor infertility with a good response to hMG served as controls. Ninety-two percent of low responders had antibodies to FSH and 65% had antibodies to LH when assessed by enzyme-linked immunosorbent assay. Similarly, 77% of low responders had ovarian antibodies. No hepatic antibodies were found in the sera of low responders, indicating that the positivity was not a general interaction with cell components. None of the "good responders" had antibodies to gonadotropins or to ovarian or liver tissue. The significant differences in antibodies between the groups supports a possible immunologic cause for low ovarian stimulation response to gonadotropin.

The presence of gonadotropin receptors in nonpregnant human uterus, human placenta, fetal membranes, and decidua.

The possible presence of gonadotropin receptors in nonpregnant human uterus and human fetoplacental unit was investigated by light microscope immunocytochemistry using a monoclonal antibody to rat luteal hCG/LH receptors. The receptor antibody cross-reacted with human and bovine hCG/LH receptors and appears to be directed against the receptor rather than other proteins, including HLA class I antigens. Uterus and fetoplacental unit contained receptor antibody-binding sites, which indicates the presence of hCG/LH receptors. In the endometrium these receptors were present in glandular and luminal epithelial cells as well as in stromal cells. In the myometrium the receptors were detected in circular and elongated myometrial smooth muscle and vascular smooth muscle. Comparison of immunostaining intensities, which indicates the presence of different amounts of receptors, revealed that luminal and glandular epithelial cells contained more receptors than stromal cells. These cells, in turn, contained more receptors than myometrial and vascular smooth muscle. All cells in secretory phase uterine specimens contained more receptors than corresponding cells from the proliferative phase of the cycle. Midpregnancy placenta, amniotic epithelium, chorionic cytotrophoblasts, and decidual cells contained hCG/LH receptors. At term pregnancy, while receptors in fetal membranes and decidua continue to be detected, placental tissues did not show any detectable receptors unless the tissues were pretreated with neuraminidase. This indicated that term pregnancy placenta contain hCG/LH receptors masked by sialic acid residues. Comparison of immunostaining intensities suggested that syncytiotrophoblasts contained more receptors than cytotrophoblasts at midpregnancy; mesenchymal cells or blood vessels contained no detectable receptors. There were more receptors in decidua than in fetal membranes at mid- and term pregnancy. While the amniotic epithelial receptors decreased, the receptors in chorionic cytotrophoblasts and decidual cells increased from mid- to term pregnancy. In summary, hCG/LH receptors were demonstrated in the nonpregnant human uterus, human placenta, fetal membranes, and decidua. This indicates that hCG/LH may directly regulate functions of these tissues by endocrine, autocrine, or paracrine mechanisms.

Ovarian antibodies detected by immobilized antigen immunoassay in patients with premature ovarian failure.

An enzyme-linked immunosorbent assay (ELISA) was used to detect ovarian and oocyte antibodies in serum from 45 patients with premature ovarian failure (POF). Control sera were obtained from a similar group of normally cycling women without POF. A specific antibody reaction was found when POF sera were tested against human ovary (47%) or oocytes (47%). A combined total of 69% of the sera were positive for either ovary or oocytes. Fewer sera were positive for antibodies against human thyroid (18%) or human placenta (22%), and virtually no reaction with human liver (4%) was seen. LH antibodies were detected by ELISA against LH in only 3 POF sera that also contained ovarian antibodies. Therefore, gonadotropin antibodies alone do not appear to account for POF. In addition, 2 patients were treated by immunosuppression and became pregnant coincident with a decline in the serum concentration of ovarian antibodies. In summary, the results of this study are consistent with previous immunohistochemical data which indicate that ovarian and oocyte antibodies are common in patients with POF. This supports the concept that some forms of POF are associated with an autoimmune process. Furthermore, detection of ovarian and oocyte antibodies by ELISA may permit routine diagnosis of autoimmune POF and provide a basis for therapy.

Comparison of monoclonal luteinizing hormone (LH) receptor antibody and LH binding sites in vibratome sections of rat ovary by immunohistochemistry.

To identify luteinizing hormone (LH) receptors, a monoclonal antibody (MAb) was produced by immunization of Balb/c mice with rat luteal cell membranes. Hybridomas, produced by a method for proteins of low antigenicity, were selected by competition with [125I]-hCG (LH) for luteal membrane binding. Conditions for analysis of LH receptor antibody (IgG2b isotype) binding by immunohistochemistry with an avidin-biotin-peroxidase complex were examined and results compared to localization of bound hCG, to detect receptors. By light microscopy, both bound hCG and the LH receptor antibody were located on luteal cell surfaces. In addition, the LH receptor antibody was associated with luteal cell cytoplasm. Cell surface membrane binding, but not cytoplasmic staining, was reduced in ovaries from rats injected with hCG. By electron microscopy, LH receptor antibody was observed in patches on luteal cell surface membranes and was associated with polysomes, small vesicles, and occasionally with discrete areas of endoplasmic reticulum. Therefore, detection of LH receptors with bound hCG may be limited to receptors found on cell surfaces, while additional LH receptors are revealed by use of a receptor antibody. The cytoplasmic LH receptor may represent stages in the processing of receptor protein. Furthermore, the methodology used in this study should be generally useful for immunohistochemistry with other MAb to receptors.

Usefulness of serial measurements of serum follicle stimulating hormone, luteinizing hormone and estradiol in patients with premature ovarian failure.

This study tests the hypothesis that serial measurements of serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) are useful in identifying a subset of patients with premature ovarian failure (POF) who may respond to high-dose human menopausal gonadotropin (hMG) therapy. Nineteen patients with POF were studied with weekly measurements of serum FSH, LH, and E2 for five consecutive weeks. Nine patients (group I) showed episodic increases in E2 (greater than 50 pg/ml), seven accompanied by decreases in FSH, and an FSH/LH ratio that was periodically less than 1.0. Ten patients (group II) displayed persistent, nonvarying low E2 and high FSH and LH levels. There was no significant difference in the E2 response to high-dose hMG (48 to 100 ampules hMG/trial) in the two groups, all patients failing to respond. In conclusion, serial assays for FSH, LH, and E2 in patients with POF fail to predict ovarian responsiveness to a trial of high-dose hMG.

Purines, prostaglandins and peptides--nature and cellular mechanisms of action of local assist and assassin agents in the ovary.

The evidence for a paracrine, progonadotropic role of adenosine in ovarian cells is summarized along with a capsule review of the origin and mechanisms of release and action of adenosine in other tissues. Briefly, adenosine markedly amplified rat and human luteal cell cyclic AMP and progesterone accumulation in the presence, but not the absence, of LH. The site of action of adenosine was found to be intracellular, linked to its phosphorylation, which resulted in increased levels of ATP. In rat luteal cells, adenosine blocked the acute antigonadotropic (luteolytic) action of PGF2 alpha. In the follicle, adenosine release from granulosal cells appeared to be stimulated by FSH. Adenosine and a nonmetabolized adenosine analog, augmented FSH-dependent inhibition of oocyte maturation in the presence or absence of an adenosine transport inhibitor. Inhibition of oocyte maturation by adenosine thus appears to be mediated by extracellular purinergic receptors. Paracrine, antigonadotropic agents also appear to regulate ovarian function. For example, GnRH elicits antigonadotropic activity in rat granulosal and luteal cells. We describe a novel, GnRH-like, ovarian hormone (GLOH) which may be the physiological ligand whose action GnRH mimics in rat ovarian cells. This protein was shown to be distinctly different from GnRH and a variety of other cyclic and noncyclic peptides. PGF2 alpha is a well known leutolytic agent and a summary of the antigonadotropic mechanism of PGF2 alpha action in rat luteal cells is presented. In these cells, the action of GnRH (or possibly the GnRH-like protein) and PGF2 alpha are mediated by separate membrane receptors but they appeared to share the same intracellular second messenger. Evidence for a role of products of phosphoinositol as a mediator of these antigonadotropic agents is summarized. We suggest that the ultimate mediator of antigonadotropic agents is Ca2+ which is released in the luteal cell in response to the intracellular mediator of antigonadotropic agents. For example, pharmacological agents which increase intracellular levels of Ca2+, mimicked the antigonadotropic action of GnRH and PGF2 alpha in rat luteal cells. Also, Ca2+ directly inhibited LH-sensitive adenylate cyclase activity in isolated luteal membranes, a paradigm in which GnRH and PGF2 alpha were inactive. The mechanism of Ca2+ action appeared to be linked to interference with GTP activation of adenylate cyclase. However, removal of extracellular Ca2+ did not abrogate the action of either GnRH or PGF2 alpha.(ABSTRACT TRUNCATED AT 400 WORDS)

Luteolytic hormones are calcium-mediated, guanine nucleotide antagonists of gonadotropin-sensitive adenylate cyclase.

We suggest that regression of the corpus luteum is an active process induced by PGF2 alpha, GnRH, and a peptide of ovarian origin whose action GnRH mimics (20). The initial events involved in luteolysis occur within minutes, and they are intimately linked to inhibition of LH action. Membrane receptor binding of luteolytic hormones activates production of a second messenger (such as a product of PI turnover) that stimulates release of sequestered, intracellular Ca2+ by a mechanism linked to inhibition of microsomal Ca2+-ATPase activity. The increase in cytosolic Ca2+ inhibits adenylate cyclase activity by blocking GTP-dependent activation of adenylate cyclase. As a result, the cell response to LH is abolished and function is lost.

Prostaglandin F2 alpha inhibits luteinizing hormone (LH)-induced increase in LH receptor binding to isolated rat luteal cells.

The effect of the luteolytic hormone prostaglandin F2 alpha (PGF2 alpha) on parameters of LH receptor binding to isolated rat luteal cells was examined. The equilibrium binding constant (0.55 X 10(10) M-1), the association rate constant (0.89 X 10(8) M min-1), and the dissociation rate constant (1.70 X 10(-2) M min-1) were not significantly altered by PGF2 alpha. However, as [125I]iodohCG binding approached equilibrium (less than 2 h) and at equilibrium (greater than 3 h), PGF2 alpha, but not PGE2, consistently reduced LH binding by 10-20%. The LH receptor-binding capacity, determined by Scatchard analysis of [125I]iodo-hCG or [125I]iodo-hLH binding, was reduced from 7.5 +/- 0.1 to 6.4 +/- 0.1 X 10(4) receptors/cell in the presence of PGF2 alpha. This reduction of total cell-bound radioactivity by PGF2 alpha was not due to a change in the rate of hormone internalization and degradation. However, when cells were briefly treated with a pulse of LH (5 ng/ml; 5-10 min), [125I] iodo-hCG (LH) binding increased 20-30% within 2 h, and PGF2 alpha prevented this LH-induced increase. A similar pulse of cAMP analogs did not alter LH binding. We conclude that while the initial binding of LH to its receptor is not altered by PGF2 alpha, it does reduce the final equilibrium level of LH binding by a mechanism that involves a block in the appearance of LH-induced cryptic receptors.

Luteinizing hormone (LH) receptor aggregation: modification of ferritin-LH binding and aggregation by prostaglandin F2 alpha and ferritin-LH.

The interaction of LH and its receptor was investigated by ultrastructural analysis of ferritin-LH (FELH) binding to isolated rat luteal cells in the absence and presence of prostaglandin F2 alpha (PGF2 alpha), an inhibitor of LH-stimulated cAMP production. FELH, with a molar ratio of FE to LH of 1:1, bound specifically to LH receptors, either singly or in small groups (microaggregates), at intervals on luteal cell surfaces. FELH elicited a dose-dependent increase in progesterone production, and its binding increased with increased FELH concentration. The number of LH receptors per cell, estimated from particle counts, was about 6.2 +/- 0.6 X 10(4), similar to estimates from Scatchard analysis of [125I]iodo-hCG binding. Microaggregate size increased in parallel with FELH binding. Only partial aggregation was seen at concentrations of FELH that elicited near-maximal progesterone secretion. Aggregation continued to increase at FELH concentrations beyond that required to elicit maximal progesterone secretion. In the presence of PGF2 alpha, FELH-stimulated progesterone production was attenuated, and FELH binding decreased from 2.9 +/- 0.4 X 10(4) to 2.1 +/- 0.3 X 10(4) receptors/cell. PGF2 alpha did not alter microaggregate size on cells labeled with FELH at 4 C when membrane fluidity was already reduced, but did substantially reduce microaggregate size at 37 C. We conclude that FELH binds initially at random sites on membranes of isolated luteal cells and that as binding increases, receptors aggregate into small groups. Furthermore, microaggregates are related in part to receptor occupancy and possibly also to levels of cAMP or activation of the adenylate cyclase mechanism.

Inhibitory characteristics of prostaglandin F2 alpha in the rat luteal cell.

Enzymatically dispersed and enriched preparations of rat luteal cells were used to characterize the antigonadotropic effects of prostaglandin (PG) F2 alpha. The half-maximal dose (ED50) of LH for stimulation of cAMP accumulation and progesterone secretion was 100 and 25 ng/ml, respectively. Methylisobutylxanthine (MIX) had no effect on the ED50 of LH on cAMP accumulation but reduced the ED50 of LH on progesterone secretion from 25 to 10 ng/ml. PGF2 alpha inhibited the tropic responses to LH by 55-70% within minutes at concentrations of PGF2 alpha within the physiological range. For example, 2-4 nM PGF2 alpha inhibited LH-stimulated cAMP accumulation by 50% (IC50). PGF2 alpha reduced the maximum cAMP response to LH but had no effect on the ED50 of LH for cAMP accumulation whereas PGF2 alpha increased the ED50 of LH on progesterone secretion by 5-7-fold. Inhibition by PGF2 alpha appeared to be unrelated to an effect on cAMP phosphodiesterase activity or to changes in parameters of LH receptor binding activity. No inhibition by PGF2 alpha was evident on LH-stimulated cAMP accumulation in isolated membranes. PGF2 alpha had little effect on cAMP accumulation in response to cholera toxin or forskolin but produced significant inhibition of progesterone secretion in response to cholera toxin or dibutyryl cAMP [Bu)2cAMP). It is concluded that the antigonadotropic effect of PGF2 alpha in the luteal cell is due to two interrelated actions: inhibition of activation of cAMP accumulation by LH and inhibition of the luteal cell response to cAMP. Since PGF2 alpha had no effect in the broken cells, it is suggested that the action of PGF2 alpha may be mediated by a second messenger in the intact cell.

Purine modulation of LH action in gonadal cells.

A rapid and marked amplification of LH and FSH-stimulated cyclic AMP accumulation and steroid secretion is produced by adenosine in luteal and granulosa cells, respectively, of both the rat and the human ovary. The rat Leydig cell response to LH, however, was unaffected by adenosine. In the luteal cell, adenine nucleotides and adenosine were equipotent with decreasing activity shown by inosine, adenine and hypoxanthine--guanosine, guanine, xanthine and pyrimidines were inactive. Both an extracellular and intracellular site appears to be involved in adenosine amplification of LH--the extracellular site accounted for about 20% of the response and may be a catalytic receptor site. The intracellular site was directly related to an increase in luteal cell ATP levels in which adenosine appears to serve as a selective prosubstrate for hormone activated adenylate cyclase. The luteal antigonadotropic action of PGF2 alpha was blocked by adenosine and these modulators were shown to be competitive antagonists of LH-stimulated cyclic AMP accumulation. Due to the ubiquitous nature of both adenosine and PGF2 alpha, (conditions have been described in other systems for their rapid release,) it is suggested that they may serve as important local humoral modulators of gonadotropin action for regulation and control of ovarian function.