Temporal changes in cervical mucus after insertion of the levonorgestrel-releasing intrauterine system.

BACKGROUND: The major contraceptive action of the levonorgestrel-releasing intrauterine system (LNG-IUS) is cervical mucus (CM) thickening, which prevents sperm penetration. No study to date has examined the temporal relationship between the insertion of the LNG-IUS and changes in CM quality and sperm penetration. STUDY DESIGN: Participants were enrolled in a clinically descriptive study to compare the quality of CM and three parameters of sperm penetration prior to insertion of the LNG-IUS and on Days 1, 3 and 5 after insertion. Measurements of estradiol, progesterone and levonorgestrel (LNG) in serum and LNG in CM were also carried out at these times. CM was analyzed using the World Health Organization CM grading criteria. Sperm penetration was determined using an in vitro sperm-CM penetration test. RESULTS: All 10 participants underwent LNG-IUS insertion during midcycle when CM quality was good and sperm penetration was excellent. On Day 1 after LNG-IUS insertion, the majority of participants demonstrated poor CM quality and poor sperm penetration. On Day 3, all participants had poor CM quality, and all but one subject had poor sperm penetration. By Day 5, all participants had poor CM quality and poor sperm penetration. LNG levels in CM peaked on the day after LNG-IUS insertion. CONCLUSION: Significant changes in quality of CM and sperm penetration were observed shortly after LNG-IUS insertion; however, CM can remain penetrable for up to 5 days when the LNG-IUS is inserted midcycle.

Sex steroid hormone levels in breast adipose tissue and serum in postmenopausal women.

Elevated levels of circulating estrogens and androgens are linked to higher breast cancer risk among postmenopausal women; however, little is known about hormone levels within the breast. Hormone concentrations within the breast may not be reflected in the blood and are likely important contributors to breast carcinogenesis. We used a previously validated method to measure levels of estrone, estradiol, androstenedione, and testosterone in adipose tissue removed as part of breast excisions performed for cancer in 100 postmenopausal women (69 ER/PR +/+ and 31 ER/PR -/-) participating in a breast cancer case-control study. We also measured the same steroid hormones, as well as estrone sulfate, and sex hormone-binding globulin (SHBG) in serum from these patients and 100 controls matched on ages at blood collection and on menopause. Overall, concentrations of serum hormones did not vary significantly between controls and cases. However, women with ER-/PR- breast cancers had lower circulating levels of all measured sex steroid hormones and higher SHBG levels than women with ER+/PR+ breast cancers and controls. Similarly, hormone concentrations in breast adipose tissue were higher among women with ER+/PR+ compared to ER-/PR- breast cancer, although differences were only significant for testosterone. These data demonstrate that high sex steroid concentrations in both serum and adipose tissues are more strongly related to ER+/PR+ than ER-/PR- breast cancers. Measurement of sex hormones in serum and in the microenvironment may help in understanding the hormonal etiology of breast cancer, suggest methods for prevention, and have value in gauging treatment response and prognosis.

Estrogen levels in nipple aspirate fluid and serum during a randomized soy trial.

BACKGROUND: On the basis of hypothesized protective effect, we examined the effect of soy foods on estrogens in nipple aspirate fluid (NAF) and serum, possible indicators of breast cancer risk. METHODS: In a crossover design, we randomized 96 women who produced 10 µL or more NAF to a high- or low-soy diet for 6 months. During the high-soy diet, participants consumed 2 soy servings of soy milk, tofu, or soy nuts (∼50 mg of isoflavones per day); during the low-soy diet, they maintained their usual diet. Six NAF samples were obtained using a FirstCyte aspirator. Estradiol (E(2)) and estrone sulfate (E(1)S) were assessed in NAF and estrone (E(1)) in serum only, using highly sensitive radioimmunoassays. Mixed-effects regression models accounting for repeated measures and left-censoring limits were applied. RESULTS: Mean E(2) and E(1)S were lower during the high-soy than the low-soy diet (113 vs. 313 pg/mL and 46 vs. 68 ng/mL, respectively) without reaching significance (P = 0.07); the interaction between group and diet was not significant. There was no effect of the soy treatment on serum levels of E(2) (P = 0.76), E(1) (P = 0.86), or E(1)S (P = 0.56). Within individuals, NAF and serum levels of E(2) (r(s) = 0.37; P < 0.001) but not of E(1)S (r(s) = 0.004; P = 0.97) were correlated. E(2) and E(1)S in NAF and serum were strongly associated (r(s) = 0.78 and r(s) = 0.48; P < 0.001). CONCLUSION: Soy foods in amounts consumed by Asians did not significantly modify estrogen levels in NAF and serum. IMPACT: The trend toward lower estrogen levels in NAF during the high-soy diet counters concerns about adverse effects of soy foods on breast cancer risk.

Sex differences in ß-amyloid accumulation in 3xTg-AD mice: role of neonatal sex steroid hormone exposure.

The risk of Alzheimer's disease (AD) is higher in women than in men, a sex difference that likely results from the effects of sex steroid hormones. To investigate this relationship, we first compared progression of ß-amyloid (Aß) pathology in male and female triple transgenic (3xTg-AD) mice. We found that female 3xTg-AD mice exhibit significantly greater Aß burden and larger behavioral deficits than age-matched males. Next, we evaluated how the organizational effects of sex steroid hormones during postnatal development may affect adult vulnerability to Aß pathology. We observed that male 3xTg-AD mice demasculinized during early development exhibit significantly increased Aß accumulation in adulthood. In contrast, female mice defeminized during early development exhibit a more male-like pattern of Aß pathology in adulthood. Taken together, these results demonstrate significant sex differences in pathology in 3xTg-AD mice and suggest that these differences may be mediated by organizational actions of sex steroid hormones during development.

Measurement of sex steroid hormones in breast adipocytes: methods and implications.

BACKGROUND: The lack of validated methods for measuring sex steroid hormones in breast tissue has limited our knowledge of their role in the development of breast cancer. We explored the feasibility of measuring hormones in breast adipocytes for epidemiologic and clinical studies by refining an existing assay procedure and assessing the reliability of hormone measurements using the modified assay. This report presents the reproducibility of measurements of androstenedione (A), testosterone (T), estrone (E(1)), and estradiol (E(2)), using breast adipose tissue samples obtained from women undergoing surgical resection for a variety of pathologic conditions. METHODS: Breast adipose tissues were obtained from 20 women. Measurements of the steroid hormones were carried out by harvesting oil from adipocytes following enzymatic digestion of the adipose tissue, extracting and chromatographing the steroids, and quantifying them by RIA. The study was conducted in three phases: first, samples from five women were used to assess the assay procedure; following this, tissues from an additional five women were assayed repeatedly to determine reproducibility of the hormone measurements. Finally, using samples from 10 women undergoing surgical resection of a breast tumor, we evaluated hormone concentrations in samples distal and proximal to the tumor. The assay coefficient of variation and intraclass correlation coefficient were used to assess hormone reproducibility. RESULTS: The within-batch coefficients of variation ranged from 5% to 17%, and between-batch estimates were between 2% and 10%, suggesting that E(1), E(2), A, and T can be reliably measured in breast adipocytes. Among samples obtained from women undergoing surgical resection of a breast tumor, hormone levels did not differ between adipose tissue fragments that were distal or proximal to the tumor, with the possible exception of E(1) in which levels were 10% higher in distal fragments. CONCLUSION: These data support the feasibility of measuring steroid hormone concentrations in breast adipocytes in epidemiologic studies. Future investigations that include the measurement of hormones in the breast microenvironment may have value in understanding breast carcinogenesis, developing prevention strategies, and assessing hormonal treatments.

Formation of ethinyl estradiol in women during treatment with norethindrone acetate.

CONTEXT: The significance of the conversion of norethindrone acetate (NET-A), a commonly prescribed, synthetic, oral progestogen, to ethinyl estradiol (EE(2)) is controversial. OBJECTIVE: We sought to determine accurately the extent to which NET-A may be converted to EE(2), and if so, whether circulating levels of EE(2) would be of clinical significance. DESIGN, SUBJECTS, AND INTERVENTIONS: We administered NET-A 10, 20, or 40 mg once daily for 7 d to 20 regularly menstruating premenopausal women and measured NET-A and EE(2) levels before drug intake; at 1, 2, 4, 8, and 24 h after the first dose; and 2 h after the seventh dose. RESULTS: The mean EE(2) maximum serum concentration obtained from the 10-, 20-, and 40-mg doses of NET-A in this study is 58, 178, and 231 pg/ml, respectively. The conversion ratio of NET-A to EE(2) ranged from 0.20 to 0.33% for the different doses. CONCLUSIONS: NET-A is converted to EE(2), and although the conversion rate is relatively small, higher doses of NET-A, as used clinically, give rise to substantial levels of EE(2).

Locus-wide chromatin remodeling and enhanced androgen receptor-mediated transcription in recurrent prostate tumor cells.

Prostate cancers (PCas) become resistant to hormone withdrawal through increased androgen receptor (AR) signaling. Here we show increased AR-mediated transcription efficiency in PCa cells that have acquired the ability to grow in low concentrations of androgen. Compared to androgen-dependent PCa cells, these cells showed increased activity of transiently transfected reporters and increased mRNA synthesis relative to levels of AR occupancy of the prostate-specific antigen (PSA) gene. The locus also displayed up to 10-fold-higher levels of histone H3-K9/K14 acetylation and H3-K4 methylation across the entire body of the gene. Although similar increased mRNA expression and locus-wide histone acetylation were also observed at another kallikrein locus (KLK2), at a third AR target locus (TMPRSS2) increased gene expression and locus-wide histone acetylation were not seen in the absence of ligand. Androgen-independent PCa cells have thus evolved three distinctive alterations in AR-mediated transcription. First, increased RNA polymerase initiation and processivity contributed to increased gene expression. Second, AR signaling was more sensitive to ligand. Third, locus-wide chromatin remodeling conducive to the increased gene expression in the absence of ligand was apparent and depended on sustained AR activity. Therefore, increased AR ligand sensitivity as well as locus-specific chromatin alterations contribute to basal gene expression of a subpopulation of specific AR target genes in androgen-independent PCa cells. These features contribute to the androgen-independent phenotype of these cells.

Long-term, low-dose lead exposure alters the gonadotropin-releasing hormone system in the male rat.

Lead is a male reproductive toxicant. Data suggest that rats dosed with relatively high levels of lead acetate for short periods of time induced changes in the hypothalamic gonadotropin-releasing hormone (GnRH) at the molecular level, but these changes were attenuated with increased concentration of exposure. The current study evaluated whether exposure to low levels of lead acetate over longer periods of time would produce a similar pattern of adaptation to toxicity at the molecular and biologic levels. Adult 100-day-old Sprague-Dawley male rats were dosed with 0, 0.025, 0.05, 0.1, and 0.3% lead acetate in water. Animals were killed after 1, 4, 8, and 16 weeks of treatment. Luteinzing hormone (LH) and GnRH levels were measured in serum, and lead levels were quantified in whole blood. Hypothalamic GnRH mRNA levels were also quantified. We found no significant differences in serum LH and GnRH among the groups of animals treated within each time period. A significant dose-related increase of GnRH mRNA concentrations with lead dosing occurred in animals treated for 1 week. Animals treated for more than 1 week also exhibited a significant increase in GnRH mRNA, but with an attenuation of the increase at the higher concentrations of lead with increased duration of exposure. We conclude that the signals within and between the hypothalamus and pituitary gland appear to be disrupted by long-term, low-dose lead exposure.

Urinary 2-hydroxyestrone/16alpha-hydroxyestrone ratio and family history of breast cancer in premenopausal women.

It has been hypothesized that the ratio of urinary 2-hydroxyestrone to 16alpha-hydroxyestrone (2-OHE1/16alpha-OHE1 represents a biomarker for breast cancer risk; the lower the ratio the higher the risk. We obtained early morning urine samples from 70 'high risk' premenopausal women who had a first degree family history of breast cancer and 27 'low risk' women with no such history. Five estrogen metabolites in urine were determined: 2-OHE1, 16alpha-OHE1, estrone (E1), estradiol (E2), and estriol (E3) conjugates. We compared geometric mean levels of each metabolite adjusted for age and weight. 'High risk' women did not have elevated levels of any of these metabolites. Instead, we observed decrements of 3-27% in women with a family history of breast cancer compared with women without such history, this difference was statistically significant for E2, 2- OHE1, and 16alpha-OHE1. The ratio of 2-OHE1/16alpha-OHE1 was identical in women with and without a family history of breast cancer. These results were unchanged, when additionally adjusted for recent intake of alcohol or cruciferous vegetables. Our data suggest that among premenopausal women, family history is not associated with higher urinary estrogen levels or a lower ratio of urinary 2-OHE1/16alpha-OHE1.