ETB receptor-mediated vasodilation is regulated by estradiol in young women.

The endothelin-B (ETB) receptor is a key regulator of vascular endothelial function in women. We have previously shown that the ETB receptor mediates vasodilation in young women, an effect that is lost after menopause. However, the direct impact of changes in estradiol (E2) on ETB receptor function in women remains unclear. Therefore, the purpose of this study was to test the hypothesis that E2 exposure modulates ETB receptor-mediated dilation in young women. Fifteen young women (24 ± 4 yr, 24 ± 3 kg/m2) completed the study. Endogenous sex hormone production was suppressed with daily administration of a gonadotropin-releasing hormone antagonist (GnRHant; Ganirelix) for 10 days; E2 (0.1 mg/day, Vivelle-Dot patch) was added back on days 4-10. We measured vasodilation in the cutaneous microcirculation (microvascular endothelial function) via local heating (42°C) on day 4 (GnRHant) and day 10 (GnRHant + E2) using laser Doppler flowmetry coupled with intradermal microdialysis during perfusions of lactated Ringer's (control) and ETB receptor antagonist (BQ-788, 300 nM). During GnRHant, vasodilatory responses to local heating were enhanced with ETB receptor blockade (control: 83 ± 9 vs. BQ-788: 90 ± 5%CVCmax, P = 0.004). E2 administration improved vasodilation in the control site (GnRHant: 83 ± 9 vs. GnRHant + E2: 89 ± 8%CVCmax, P = 0.036). Furthermore, cutaneous vasodilatory responses during ETB receptor blockade were blunted after E2 administration (control: 89 ± 8 vs. BQ-788: 84 ± 8%CVCmax, P = 0.047). These data demonstrate that ovarian hormones, specifically E2, modulate ETB receptor function and contribute to the regulation of microvascular endothelial function in young women.NEW & NOTEWORTHY The endothelin-B (ETB) receptor mediates vasodilation in young women, an effect lost following menopause. It is unclear whether these alterations are due to aging or changes in estradiol (E2). During endogenous hormone suppression (GnRH antagonist), blockade of ETB receptors enhanced cutaneous microvascular vasodilation. However, during E2 administration, blockade of ETB receptors attenuated vasodilation, indicating that the ETB receptor mediates dilation in the presence of E2. In young women, ETB receptors mediate vasodilation in the presence of E2, an effect that is lost when E2 is suppressed.

Validation study of the Access antimüllerian hormone assay for the prediction of poor ovarian response to controlled ovarian stimulation.

OBJECTIVE: To evaluate the diagnostic performance of the antimüllerian hormone (AMH) level determined using the Access AMH assay for predicting poor ovarian response (POR) defined as ≤4 oocytes retrieved, including the validation of the predefined AMH cutoff of 0.93 ng/mL in both serum and plasma. DESIGN: Prospective cohort study. SETTING: Fifteen private and academic fertility centers (14 in the United States and 1 in Canada). PATIENT(S): Women aged 21-45 years planning controlled ovarian stimulation for in vitro fertilization. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Number of oocytes retrieved, categorized as POR and normal-to-high ovarian response (non-POR). The correlation of AMH level and antral follicle count. RESULT(S): Data were available for 472 participants who completed the study (74 with POR and 398 non-POR). The mean AMH serum level among those with POR was 0.99 ng/mL (median 0.76 ng/mL) compared with 2.83 ng/mL (median 2.36 ng/mL) among the normal-to-high responders. For confirmation of the 0.93 ng/mL AMH level cutoff as a predictor of POR, a receiver operating characteristic analysis gave an area under the curve of 0.852, with corresponding sensitivity and specificity of 63.5% and 89.2%, respectively. The associated positive predictive value was 52.2% and the negative predictive value was 92.9%. The AMH plasma values demonstrated a strong correlation with AMH serum values with an r value = 0.9980. The previously established AMH cutoff of 1.77 ng/mL for antral follicle count >15 resulted in a sensitivity of 83.8% (95% confidence interval [CI] 77.7-88.5) and a specificity of 59.9% (95% CI 54.2-65.4). CONCLUSION(S): This study validated the previously established AMH cut-point for the prediction of POR. Because this cut-point may vary depending on the assay used, the specific AMH assay should be reported in the literature whenever possible.

Should embryos developing to blastocysts on day 7 be cryopreserved and transferred: an analysis of pregnancy and implantation rates.

OBJECTIVE: To compare pregnancy rates (PRs) using blastocysts cryopreserved on day 7 with those cryopreserved on days 5 and 6. DESIGN: Retrospective observational cohort study. SETTING: Infertility center performing IVF. PATIENT(S): Eight hundred women with infertility undergoing frozen ET. INTERVENTION(S): Blastocysts cryopreserved on days 5, 6, and 7 after retrieval were thawed and transferred. MAIN OUTCOME MEASURE(S): Ongoing PRs (pregnancy developing appropriately into the second trimester). Thaw survival, implantation rates, and clinical PRs were also calculated. RESULT(S): A total of 1,406 embryos were thawed with a survival of 90.7% for day 5, 83.7% for day 6, and 78.7% for day 7. Implantation rates were 43.3%, 28.9%, and 28.9%, respectively. Ongoing PRs were 43.9%, 32.9%, and 26.7%, respectively. CONCLUSION(S): Blastocysts cryopreserved on day 7 have a lower, but clinically important potential. Embryos that do not achieve blastocyst stage on day 6 should not be universally discarded, but should be observed in culture 1 more day as 27% may result in an ongoing pregnancy.

Improved endometrial assessment using cyclin E and p27.

OBJECTIVE: To evaluate endometrial expression of cyclin E and p27 in fertile and infertile women. DESIGN: Retrospective clinical study. SETTING: University medical center and private practice. PATIENT(S): Thirty-three fertile volunteers, 83 women seeking infertility treatment, and 23 women undergoing mock cycles. INTERVENTION(S): Endometrial biopsy. MAIN OUTCOME MEASURE(S): Cyclin E and p27 immunohistochemistry. RESULT(S): Glandular cyclin E and p27 expression dramatically changed in intensity and subcellular localization throughout the menstrual cycle. In normal control biopsies, glandular cyclin E progressed from the basal to the lateral cytoplasm (midproliferative phase) to the nucleus (days 18 to 19) and was absent in biopsies after day 20. First appearing on days 17 to 19, p27 was found only in the nuclei. Cyclin E was more frequently seen after day 20 in infertility patients. In the hyperstimulated cycles, staining for cycle E in proliferative samples was more intense than in the natural cycles, but p27 staining was unchanged. CONCLUSION(S): Cyclin E and p27 may be clinically useful markers of development in the endometrium. As cell cycle regulators, cyclins reveal underlying biochemical processes driving endometrial progression and may partly represent the means by which estrogen and progesterone regulate this dynamic tissue.

Modulation of trophoblast function by tumor necrosis factor-alpha: a role in pregnancy establishment and maintenance?

OBJECTIVE: Trophoblast differentiation is a critical process for successful implantation and establishment of the human placenta. The aim of this study was to characterize the effect of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) on the expression of markers of trophoblast function and differentiation. STUDY DESIGN: Human cytotrophoblasts were stimulated with 1 and 10 ng/mL recombinant TNF-alpha or IL-6. Cell viability was determined and conditioned culture media was analyzed by gelatin zymography to assess protease secretion and by enzyme-linked immunosorbent assays to measure production of beta-human chorionic gonadotropin and oncofetal fibronectin. RESULTS: TNF-alpha increased secretion of urokinase-type plasminogen activator up to 3-fold of basal unstimulated production. Stimulation of cytotrophoblasts with this cytokine also inhibited beta-human chorionic gonadotropin secretion up to 75%. TNF-alpha did not modify the secretion of matrix metalloproteinase-9 and oncofetal fibronectin. IL-6 had no effect on these trophoblast differentiation markers. CONCLUSION: These results show that TNF-alpha stimulated cytotrophoblasts modulate the expression of differentiation markers, down-regulating the autocrine signals that promote syncytialization, and increasing their invasive capacity through up-regulation of proteases. We suggest that this regulatory mechanism of trophoblast function could play an important role during trophoblast implantation, in pregnancy failure and in the normal and pathologic rupture of fetal membranes.