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PubMedDate not supplied

Transdermal administration of estradiol and norethisterone: effect on the uterus and uterine arteries.

OBJECTIVE: To evaluate the short- and long-term effect on the uterus, endometrium, and vascular reactivity of uterine arteries of sequential transdermal estradiol (50 microg/day) and norethisterone (0.25 mg/day in the last 14 days of each cycle). DESIGN: An intravaginal ultrasound evaluation was performed in 48 postmenopausal women before and at the 3rd and 12th month of treatment, during the last 3 days of both estradiol alone and estradiol plus norethisterone. An endometrial biopsy was also performed before and at the end of treatment. In 11 participants, intravaginal ultrasound and endometrial biopsy were repeated after 48 months of treatment. RESULTS: Uterine volume (33.7 +/- 3.3 cm3 to 56.8 +/- 3.7 cm3; p = 0.001) and endometrial thickness (3.07 +/- 0.48 mm to 5.74 +/- 0.41 mm; p = 0.001) increased within 3 months, with no further increases. Thickness was similar in the estradiol and estradiol-norethisterone phase. Endometrial hyperplasia was found in one participant at 12 months of treatment. A significant decrease (p = 0.002) in the pulsatility index of uterine arteries was observed only during the estradiol phase. After 48 months of treatment, the pulsatility index of uterine arteries was lower than at baseline (2.78 +/- 0.24 vs. 2.23 +/- 0.33; p = 0.044) even when evaluated in the combined phase. CONCLUSIONS: The transdermal administration of sequential estradiol and norethisterone reduces uterine artery resistance and induces a self-limiting growth of the uterus and endometrium.

Administration, Cutaneous↗
PubMed2000

Enhanced responses to 17beta-estradiol in rat hearts treated with isoproterenol: involvement of a cyclic AMP-dependent pathway.

We determined the effects of 17beta-estradiol, the most effective estrogen, acutely administered, on the heart/ventricular myocyte with or without treatment with isoproterenol (Iso). At 0.1 to 1 nM, 17beta-estradiol, which itself had no effect, reduced the heart rate and developed pressures in the isolated perfused heart treated with 10(-7) M Iso. One nanomolar 17beta-estradiol also inhibited the cyclic AMP (cAMP) production in Iso-treated ventricular myocytes. At 10 nM to 1 microM, 17beta-estradiol itself reduced the heart rate and incidence of ischemia/reperfusion-induced arrhythmias, with the exception of diastolic pressure. The effects of 17beta-estradiol on heart rate, systolic and mean pressures, and arrhythmias were significantly enhanced in the heart/ventricular myocyte treated with Iso. Tamoxifen, an estrogen receptor antagonist, did not antagonize the effect of 17beta-estradiol on the Ca(2+) current in ventricular myocytes treated with Iso, nor did it alter the effect of the hormone on the cAMP production augmented by Iso and forskolin. The effects of 17beta-estradiol on Ca(2+) current in the presence or absence of tamoxifen and/or Iso were similar in male rats, which do not possess the estrogen receptor, and female rats, which have the estrogen receptor. In conclusion, we have shown for the first time that estrogen at physiological concentrations modulates negatively the stimulatory actions of Iso on the heart rate and cardiac contractility. The effects may result from activation of an unknown membrane receptor and the adenylate cyclase/cAMP pathway, which enhances Ca(2+) influx across the L-type Ca(2+) channel.

Adrenergic beta-Agonists↗
PubMed2000

Administration of 17beta-estradiol attenuates retinal ischemia-reperfusion injury in rats.

PURPOSE: Accumulating evidence has suggested that 17beta-estradiol exerts protective effects against ischemic damage in various organs. In addition, leukocytes that accumulate in postischemic tissues are thought to play a central role in ischemia-reperfusion injury. This study was designed to evaluate quantitatively the inhibitory effects of 17beta-estradiol on leukocyte accumulation during ischemia-reperfusion injury and on subsequent retinal damage after transient retinal ischemia. METHODS: Transient (60 minutes) retinal ischemia was induced in male rats by temporary ligation of the optic nerve. Thirty minutes before induction of ischemia, 17beta-estradiol (0.1 mg/kg) was administered intraperitoneally. At 6, 12, 24, and 48 hours after reperfusion, leukocyte accumulation in the retina was evaluated in vivo by means of acridine orange digital fluorography. Histologic and electroretinographic (ERG) studies were carried out to evaluate retinal damage. RESULTS: Treatment with 17beta-estradiol significantly inhibited postischemic leukocyte accumulation; the maximum number of accumulating leukocytes was reduced by 35.7% at 24 hours after reperfusion (P = 0.01). Histologic examination showed that administration of 17beta-estradiol significantly reduced retinal damage, which was most obvious in the inner retina, 168 hours after reperfusion (P = 0.0001). ERG studies at 12 and 168 hours after reperfusion showed that recovery of the b-wave amplitude was significantly improved with treatment of 17beta-estradiol (P = 0.023). CONCLUSIONS: The present study demonstrated the inhibitory effects of 17beta-estradiol on leukocyte accumulation and subsequent tissue injury during retinal ischemia-reperfusion injury.

Acridine Orange↗
PubMedDate not supplied

[Effects of a sequential combination of estradiol valerate and cyproterone acetate on the functional properties of the arterial wall in menopausal women].

Several studies have shown that estrogen replacement therapy protects postmenopausal women against coronary artery disease. This protective effect has been ascribed to the hormone's effect on serum lipids, as well as a direct action on the vascular wall. Concurrent administration of a progestin to protect women from the risk of endometrial hyperplasia may alter the protective effects of estrogen. The aim of this study was to assess the evolution of the endothelial function in postmenopausal women given a sequential combination of oral 2 mg estradiol valerate for 11 days, followed by 2 mg estradiol valerate associated with 1 mg cyproterone acetate for ten days (Climène). Each 21-day sequence was followed by a seven-day treatment-free interval. The women received a three-month treatment course. Thirty-one healthy postmenopausal women participated in the study (median age: 51 years; range: 45-59 years). Flow-mediated dilatation (FMD), a reflection of endothelium-dependent vasomotor function, increased from 8.47% at baseline (range: 4.57-11.02%) to 9.64% (range: 7.07-13.12%) at the end of the first treatment cycle; i.e., a 15% increase over baseline (P < 0.0001). FMD further increased after three treatment cycles to 10.59% (range: 8.09-15.22%); i.e., a 28.6% increase over baseline (P < 0.0001). FMD at the end of the first combined sequence or after the 11 days of estradiol only were similar (delta = 0.25%; range: -2.31-5.81%; not significant). In conclusion, in postmenopausal women, a three-month sequential treatment combining estradiol valerate and estradiol valerate plus cyproterone acetate (Climène) has beneficial effects on endothelial function as demonstrated by the evolution of the FMD. There was no decrease in the effect of estradiol on FMD when cyproterone acetate was added to estradiol.

Arteries↗
PubMed2000

[Use captopril and estradiol-medroxyprogesterone in premenopausal hypertensive patients].

INTRODUCTION: The premenopause period is that which precedes the actual menopause, when a decrease of the ovarian hormones is present, leading to cardiovascular diseases as arterial hypertension, acute myocardial infarction and cerebrovascular diseases. OBJECTIVE: We evaluated the antihypertensive response of the estradiol-medroxyprogesterone, to reduce arterial pressure in the premenopausal patient. MATERIAL AND METHODS: In a clinical trial from March 1997 to September 1998, 106 patients with systemic hypertension, symptoms hypoestrogenism and estradiol levels less than 30 pg/mL were evaluated. They were randomized at a trial in two groups with pursuit of 6 months. Group A: 53 with captopril, Group B: 53 with estradiol-medroxyprogesterone. The arterial pressure, cholesterol, triglycerides and symptoms hypoestrogenism were analyzed before and after the treatment. The statistical analysis was performed with Student T. RESULTS: A decrease of arterial pressure was observed with estradiol, the same as with captopril with a p < 0.05. Decrease of cholesterol and triglycerides were more significant in the estradiol group with a p < 0.05. A bigger attenuation of symptoms of the hypoestrogenism existed in the estradiol group. CONCLUSIONS: The antihypertensive response with estradiol was the same as with captopril in the premenopausal patient with systemic hypertension.

Antihypertensive Agents↗
PubMed2001

Effect and safety of 17 beta-estradiol vaginal tablet in postmenopausal women with urogenital symptoms.

OBJECTIVE: To evaluate the effects of a 17 beta-estradiol vaginal tablet on urogenital symptoms, vaginal pH, vaginal cytology, endometrial thickness, and plasma estradiol level in postmenopausal women with urogenital symptoms. METHOD: Twenty-seven postmenopausal women with urogenital symptoms received 25 microg of a 17 beta-estradiol tablet intravaginally daily for the first 2 weeks, followed by 10 weeks of twice a week dosage. The results of urogenital symptoms, vaginal pH, vaginal cytology, endometrial thickness, and plasma estradiol level were analysed. RESULTS: The urogenital symptoms improved significantly in all women. The mean vaginal pH was significantly decreased. The vaginal cytology showed estrogenic effect on the karyopyknotic index and the maturation value. There was no significant difference in endometrial thickness and level of plasma estradiol before and after treatment. There was one case of vaginal bleeding from endometrial proliferation. CONCLUSION: Local vaginal treatment of 17 beta-estradiol (25 microg) had a positive effect on the urogenital symptoms, vaginal pH, and vaginal cytology. No elevation of plasma estradiol level was detected after treatment.

Administration, Intravaginal↗
PubMed2002

Simplified artificial endometrial preparation, using oral estradiol and novel vaginal progesterone tablets: a prospective randomized study.

There are various successful protocols for artificial endometrial preparation, comprising induction of endometrial proliferation with estrogens and secretory transformation with progestins. The aim of this prospective randomized study was to evaluate a simplified approach for endometrial preparation, comparing two constant doses of oral estradiol combined with a novel low-dose vaginal natural progesterone preparation (100 mg Endometrin tablets). Twenty-nine patients were enrolled in the study and divided randomly into two groups. Both groups received oral estradiol tablets from the beginning of menstruation, group A (15 patients) receiving 4 mg/day divided into two doses of 2 mg each, and group B (14 patients) receiving 6 mg/day divided into three doses. Serum estradiol and progesterone and sonographic thickness of the endometrium were measured on the 1st day of menstruation and on the 6th, 11th, 16th and 21st days of the artificial cycle. Following the first 12 days of estradiol priming, with an endometrial thickness of > or = 8 mm, Endometrin vaginal tablets 100 mg were added twice a day for 10 days. On the 21st cycle day, an endometrial biopsy was taken from all patients using Pipelle. In all 29 patients, appropriate changes in estradiol, progesterone and endometrial thickness were observed. Estradiol levels were significantly higher in the 6 mg/day group on days 6 and 11, but no significant difference was noted in serum progesterone level and endometrial thickess between groups. Histological evaluation of endometrial biopsies, on the 21st day, revealed adequate late-secretory endometrium in 14/15 (93.3%) patients of group A and in 13/14 (92.9%) patients of group B. In conclusion, our results demonstrate that an appropriate endometrial secretory transformation may be induced using an economical regimen of fixed low-dose oral estradiol (4 mg/day) and low-dose vaginal progesterone tablets (Endometrin 100 mg twice daily).

Administration, Intravaginal↗
PubMed2002

The pattern of estradiol and progesterone differs in serum and tissue of benign and malignant ovarian tumors.

Epidemiological studies have indicated a relationship between gonadal steroid hormones and ovarian cancer. A production of both estradiol and progesterone by ovarian cancers has been demonstrated. The local steroid concentrations and the putative relation to histopathological and clinical condition were investigated herein. Ovarian tissue, ovarian tumor cyst fluid, ovarian vein samples and peripheral serum concentrations of estradiol and progesterone in pre- and post-menopausal women, subdivided into groups with normal ovaries, benign, borderline and malignant ovarian tumors, were quantitatively assessed. Both ovarian tissue concentrations of estradiol and progesterone were more than 100-fold higher than in serum. Based on differences in concentrations between different ovarian tumor groups, the data is not coherent with the previously suggested increased production of estradiol and progesterone in ovarian cancer tissue, since post-menopausal women with ovarian cancer presented lower median tissue hormone levels, most pronounced between malignant and benign tumors; median (25 and 75 percentile) estradiol; 9.40 (6.67-15.50) vs 16.44 (12.49-23.20), p=0.02 and progesterone; 308 (240-575) vs 957 (553-1143) pmol/g wet weight, p<0.01, n=81. Lower concentrations of estradiol, but not progesterone, were found in ovarian cancer tissue, ovarian cyst fluid and peripheral serum in patients with FIGO stages 3 and 4 than in stages 1 and 2. The novel finding of a large ovarian tissue to serum difference of both estradiol and progesterone indicates an important role of ovarian tissue concentrations in tumor biology and raises the question of adequate doses of anti-hormonal therapy in women with ovarian cancer.

Cyst Fluid↗
PubMed2001

[Effects of estradiol and isoflavoid on the expression of adhesion molecules on neutrophils].

OBJECTIVE: To elucidate the effects of estradiol and isoflavoid on the expression of adhesion molecules on neutrophils. METHODS: Neutrophils of healthy subjects and ischemic stroke patients were treated with tumor necrosis factor alpha (TNF alpha), in the presence or absence of different concentrations of isoflavoid (WZ1, WZ2) and estradiol (WZ3, WZ4). Flow cytometry was used to detect the expression of CD18 and CD62L on neutrophil surface. RESULTS: 1. 10 ng/ml TNF alpha could activate neutrophils of healthy subjects; it increased the expression of CD18 by 10% on neutrophil surface and shed CD62L from the surface as shown by a 15% decrease of the fluorescence intensity and a 30% decrease of the percentage of positive cell. 2. Isoflavoid (WZ1, WZ2) had no significant effect on the expression of CD18 and CD62L on neutrophils. 3. Pretreatment of neutrophils with estradiol (WZ3, WZ4) could inhibit the activation of neutrophils by TNF alpha, which decreased the fluorescence intensity of CD18 by 8%, increased the fluorescence intensity of CD62L by 15% and increased the percentage of CD62L positive cell by 20%. 4. TNF alpha could activate the neutrophils of ischemic stroke patients strikingly; it increased the fluorescence intensity of CD18 by 20% and decreased the fluorescence intensity and percentage of positive cell of CD62L by 30%, and there was a significant difference when the patients were compared with the healthy subjects. Estradiol had the same effect on the expression of CD18 and CD62L as on those of healthy subjects. CONCLUSION: 1. TNF alpha is a strong activator of neutrophils; it plays an important role in the occurrence and development of ischemic stroke. 2. Isoflavoid has no obvious effect on the expression of adhesion molecules on neutrophils, so its role in protecting the cardiovascular system may come into play not by the way of affecting adhesion molecules expression. 3. Pretreatment of neutrophils with estradiol could protect them from activation by TNF alpha, thus decreasing the expression of adhesion molecules, the adhesion of neutrophils -endothelial cells, and hence the risk of ischemic stroke. However, in case that the neutrophils have been activated by TNF alpha, estradiol has no effect on the expression of adhesion molecules; this implies that estradiol possibly has no valid anti-adhesion therapeutic effect on ischemic stroke.

Adult↗
PubMed1992

[Sex difference of free erythrocyte protoporphyrin (FEP) level. III. Effect of estradiol on porphyrin metabolism, especially in FEP, in lead poisoned rats].

An experimental study of sex hormone on FEP level in rats was conducted to clarify sex difference of FEP level. A total of 42 male Donryu rats were divided into 7 groups; group I (control 1; olive oil injection without castration), group II (control 2; olive oil alone), group III (EL; estradiol in olive oil, 50 micrograms/kg.BW), group IV (EH; estradiol in olive oil, 250 micrograms/kg.BW), group II' (Pb; Pb 5 mg/kg.BW), group III' (PbEL; Pb 5 mg/kg.BW + estradiol in olive oil, 50 micrograms/kg.BW) and group IV' (PbEH; Pb 5 mg/kg.BW+estradiol in olive oil, 250 micrograms/kg.BW). Excluding group I, all rats of the 6 groups were castrated. After one week from castration, estradiol was subcutaneously injected 4 times a week, and lead was intraperitoneally injected once a week for 6 wk. Estradiol suppressed growth, Ht, Hb value and liver function, but did not show any evident effect on FEP, ALA-U and CP-U. Erythrocyte ALA-D activity in group IV' (Pb+estradiol at high dose) showed a level higher than that in group II' (Pb-treatment alone).

Alanine Transaminase↗
PubMedDate not supplied

17-beta estradiol down regulates ganglionic microglial cells via nitric oxide release: presence of an estrogen receptor beta transcript.

OBJECTIVES: In earlier studies we have demonstrated that 17-beta-estradiol and an estrogen cell surface receptor can be found on various human cells where they are coupled to nitric oxide release. We also demonstrated the presence of estrogen signaling in Mytilus edulis ganglia. In the present report, we sought to determine a function for these ganglionic estrogen receptors, transcending a reproductive role for estrogen. MATERIAL & METHODS: Ganglionic microglial egress from excised pedal ganglia was examined microscopically following pharmacological treatments designed to determine a role for 17-beta-estradiol in microglial regulation via nitric oxide. Additionally, we examined the tissue by RT-PCR and sequence analysis for the estrogen receptor beta gene. RESULTS: In ganglia incubated with varying concentrations of 17-beta-estradiol-BSA there is a significant drop in microglial egress at the 24 hour observation period (58.7 +/- 7.4 vs. 17-beta-estradiol-BSA exposed = 14.7 +/- 1.5; P<0.01), which can be antagonized by tamoxifen and significantly diminished by L-NAME, a nitric oxide synthase inhibitor. By RT-PCR and sequence analysis Mytilus edulis pedal ganglia was found to express a 266 bp fragment of the estrogen receptor-beta gene, which exhibits 100% sequence identity with the human counterpart. CONCLUSION: These data suggest that 17-beta-estradiol-BSA is working on estrogen cell surface receptors since 17-beta-estradiol-BSA does not enter the cytoplasm and that these receptors are coupled to constitutive nitric oxide release. This study demonstrates that 17-beta-estradiol can down regulate microglial fMLP induced activation and activation following ganglionic excision.

Animals↗
PubMed2003

Estradiol differentially regulates c-Fos after focal cerebral ischemia.

Estrogen replacement therapy enhances mood, delays cognitive decline, and reduces the risk of neurodegeneration. Our laboratory has shown previously that pretreatment with low physiological levels of estradiol protects against middle cerebral artery occlusion (MCAO)-induced brain injury during late phases of neuronal cell death. Immediate early genes (IEGs) are induced by various forms of brain injury, and their induction is known to be a critical step in programmed cell death. The current study tested the hypothesis that the ability of estradiol to reduce MCAO-induced cell death involves attenuation of expression of one or more IEGs. We examined the effects of MCAO on the temporospatial pattern of IEG expression and the modulation of this pattern by estradiol replacement. Rats were ovariectomized and treated with either vehicle or low physiological concentrations of estradiol. One week later, rats underwent MCAO and brains were collected 1, 4, 8, 16, and 24 hr later. We assessed IEG mRNAs in discrete regions of brain by RT-PCR at 24 hr. We examined expression of c-Fos mRNA and protein in greater detail using in situ hybridization and immunohistochemistry to delineate the time course and specific regions of cortex in which estradiol influenced its expression. Our results reveal that c-fos, fosB, c-jun, and junB levels were upregulated at 24 hr. Furthermore, estradiol selectively affected the expression of c-Fos mRNA and protein by attenuating the injury-induced increase in a time- and region-specific manner. Our findings strongly suggest that the ability of estradiol to protect against MCAO-induced cell death involves attenuation of c-Fos induction.

Animals↗
PubMed2001

Different action of ovine GH on porcine theca and granulosa cells proliferation and insulin-like growth factors I- and II-stimulated estradiol production.

Growth hormone (GH) and insulin-like growth factors (IGFs) are recognized as regulators of ovarian function. This study was designed to compare the effect of GH and IGFs added alone or together on porcine theca interna and granulosa cells proliferation and steroidogenesis. Moreover, the effect of GH on IGF-I secretion was examined. Cells were isolated from medium size follicles and cultured in vitro for 48 h in serum free medium. Estradiol and IGF-I medium concentrations were determined by radioimmunoassays. Proliferation was evaluated by alamar blue assay and by radiolabelled thymidine incorporation. GH increased IGF secretion by granulosa cells while decreased its secretion by theca cells. Proliferation of both cell types was stimulated by IGF-I and IGF-II (30 ng/ml) and modestly inhibited by GH (100 ng/ml). Insulin-like growth factor II increased, in a statistically significant manner, estradiol secretion by both cell types, while IGF-I stimulated estradiol secretion to a greater extent by granulosa then by theca cells. The synergistic action of GH and IGFs on estradiol secretion was stimulatory in theca cells and inhibitory in granulosa cells. These data demonstrate that despite its direct action on estradiol secretion by granulosa and theca cells, GH also modulated estradiol secretion induced by IGFs. Differences in the estradiol production in response to GH alone and the effect of the synergistic action of GH and IGFs suggest that different cellular mechanisms for these hormones are triggered in each cell type.

Animals↗
PubMed2004

Influence of stroma-derived growth factors on the estradiol-stimulated proliferation of human breast cancer cells.

PURPOSE OF INVESTIGATION: Estradiol is the main proliferating substance for human epithelial breast cells. There is evidence that proliferation is also stimulated by growth factors mainly synthesized by the surrounding stroma. In the present in vitro study we have compared the proliferating activity of three growth factors alone and in combination with estradiol in human breast cancer cells. METHOD: As a cell model the well-recognized human breast cancer cell line MCF-7 was used. The growth factors tested were basic fibroblast growth factor (bFGF), epithelial growth factor (EGF) and insulin-growth factor-1 (IGF-I) at the concentrations 10(-10), 10(-9) and 10(-8) M alone and in equimolar combination with 10(-10) M estradiol. Cell proliferation was measured after seven days incubation by the ATP-assay. RESULTS: The growth factors alone significantly stimulated proliferation of MCF-7 cells in the tested concentration range. The increases were about 40% for EGF, between 40 and 60% for FGF and between 30 and 90% for IGF-I. The strongest proliferating factor was estradiol alone with values between 70 and 130%. For all three growth factors an additive effect was seen in combination with estradiol, which was greatest for IGF-I. CONCLUSION: These data indicate that estradiol is the strongest proliferating factor for human breast cancer cells. Therefore the predictive value of cell models using estradiol as a proliferative agent seems to be highly reliable. However, stromal influence by growth factors should not be disregarded, since proliferation of pre-existing malignant cells may be accelerated by the concomitant presence of estrogens and growth factors.

Breast Neoplasms↗
PubMed2004

The effect of estradiol on the oxidative damage and trace element level determined in the liver of rats treated with dimethylarsinic acid.

DMA--dimethylarsinic acid (cacodylic acid)--used as an herbicide, is the major metabolite formed after the exposure to inorganic arsenics in mammals. It is considered to have an important role in arsenic carcinogenesis through the induction of oxidative damage in various tissues. Estradiol, apart from its main hormonal effect, displays both prooxidative and antioxidative action depending on the condition of the treatment. The oxidative stress plays a crucial role in estrogen-induced carcinogenesis. In the experiments performed in female Wistar rats receiving drinking water ad libitum with 0.01% DMA for 10 weeks, one half of rats was treated with 17beta-estradiol (0.1 mg/rat s.c., twice a week) starting the 3rd week. One more group received estradiol only and last group served as controls receiving drinking water without treatment. The DMA enhanced lipid peroxidation in the liver, estradiol treatment potentiated this effect of arsenic. The GSH level was enhanced in DMA+estradiol treated group. In estradiol-only treated group both the lipid peroxidation and GSH content were increased. The administration of estradiol caused an enhancement of several trace element concentrations in the liver, mainly that of iron and copper. The critical role of estrogen on the development of oxidative stress was thus proved.

Administration, Oral↗
PubMed2003

[High concentrations of serum estradiol in assisted reproduction].

OBJECTIVES: To analyze the influence of the levels of estradiol on the day of HCG in the pregnancy rate (PR) of ICSI and oocyte donation. STUDY DESIGN: Retrospective, comparative. MATERIAL AND METHODS: 333 patients underwent ICSI and 66 in oocyte donation were included dividing them according to the level of estradiol: a) < 1,000 pg/mL, b) 1,001-3,000 pg/mL and c) > 3,000 pg/mL. Therapeutic protocol: Down regulation with acetate leuprolide in late luteal phase, COH with FSHr and/or HMG, ultrasonographic monitoring and estradiol blood levels, HCG application with > 3 follicles > 18 mm, oocyte retrieval 34 hours later. We analyzed: PR, age (including receptors), FSH and LH. Number, mature grade and fertilized oocytes; luteal support, transfer quality and type of catheter. Statistical analysis (SPSS 11) with chi square, ANOVA and Kruskall-Wallis. RESULTS: ICSI: Older patients in group A (p < 0.001), but without difference between B and C groups (p = 0.08). Statistical difference in number of follicles, number of oocytes, fertilized oocytes and transferred embryos being less in the A group (p < 0.001). Statistical difference in PR 21.7, 35.6 and 25.7% in A, B and C groups respectively (p = 0.032). Oocyte donation: Group A has younger patients (p = 0.005), FSH and LH were similiar among groups. Major number of follicles were observed to increase estradiol levels, but major quantity of metaphase II and fertilized oocytes were observed in group B (p = 0.05). PR without significant differences: 50, 51.5 and 52.3% in groups A, B and C (p = 0.977). Without statistical difference in the age of receptors; transferred embryos, type of catheter and quality on ICSI and oocyte donation groups. CONCLUSION: High estradiol levels at the day of HCG application affect the PR in patients submitted to ICSI. The best results were obtained with estradiol levels between 1,000 and 3,000 pg/mL. In oocyte donation the high concentrations of estradiol do not affect the PR of the receptors.

Adult↗
PubMed2004

[Effect of 17beta-estradiol on Kv2.1 current and delayed rectifier potassium current in cultured rat hippocampal neurons].

AIM: To study the effects of 17beta-estradiol on Kv2.1 potassium channel current and delayed rectifier potassium current (IK) in cultured rat hippocampal neurons. METHODS: The effects of 17beta-estradiol on Kv2.1 channel current and IK in cultured rat hippocampal neurons were observed using the whole cell patch clamp techniques. RESULTS: 17beta-Estradiol was shown to reduce the amplitude of Kv2.1 current and IK in concentration-dependent manners. The IC50s of 17beta-estradiol blocking Kv2.1 and IK were 2.4 and 4.0 micromol x L(-1), respectively. 17beta-Estradiol (3 micromol x l(-1)) significantly shifted the steady-state activation and inactivation curves of Kv2.1 current to negative potentials. However, it only produced the shift of the steady-state activation curve of IK to the negative potential without effect on the steady-state inactivation of IK. CONCLUSION: 17beta-Estradiol inhibits Kv2.1 and IK of hippocampus at similar level. The inhibition of 17beta-estradiol on IK current may be partially via blocking Kv2.1 current.

Animals↗
PubMed2005

Phytoestrogen exposure correlation with plasma estradiol in postmenopausal women in European Prospective Investigation of Cancer and Nutrition-Norfolk may involve diet-gene interactions.

Cross-sectional studies investigating the relationship between phytoestrogens in diet, urine, or blood with plasma estradiol and sex hormone binding globulin (SHBG) have been inconclusive. We investigated the relationship among phytoestrogen exposure, polymorphisms in the ESR1, COMT, CYP19, and SHBG genes, and plasma estradiol and SHBG levels in 125 free-living postmenopausal women taking part in a cohort study (European Prospective Investigation of Cancer and Nutrition-Norfolk) using three different markers: dietary, urinary, and serum phytoestrogens. Phytoestrogen levels (daidzein, genistein, glycitein, O-desmethylangolensin, equol, enterodiol, and enterolactone) in spot urine and serum were analyzed by gas chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry, respectively. Plasma estradiol and SHBG were measured by immunoassays. Adjusting for age and body mass index, urinary daidzein, genistein, glycitein, and serum daidzein and glycitein were negatively correlated with plasma estradiol (R = -0.199 to -0.277, P <0.03), with particularly strong associations found in the 18 women with CC genotype for ESR1 PvuII polymorphism (R = -0.597 to -0.834, P < 0.03). The negative correlations observed between isoflavones and estradiol in women as a whole became no longer significant when we excluded women with ESR1 PvuII CC genotype, indicating that the correlations observed were due mainly to this group of women. There was no relationship between dietary isoflavones and plasma estradiol and no association was found between any of the dietary, urinary, and serum phytoestrogen and plasma SHBG or between these factors and polymorphisms in CYP19, SHBG, and COMT. We conclude that higher isoflavone exposure is associated with lower plasma estradiol in postmenopausal women and that this preliminary study is suggestive of the involvement of diet-gene interactions.

Aged↗