MetaboLights
A 3-hydroxy steroid that is 17beta-estradiol which has been substituted at the 15alpha and 16alpha positions by two additional hydroxy groups. It is a natural estrogen produced exclusively during pregnancy by the fetal liver.
Identification
estra-1(10),2,4-triene-3,15alpha,16alpha,17beta-tetrol
(15alpha,16alpha,17beta)-estra-1(10),2,4-triene-3,15,16,17-tetrol
(8R,9S,13S,14S,15R,16R,17R)-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,15,16,17-tetrol
15alpha-hydroxyestriol
3,15alpha,16alpha,17beta-tetrahydroxyestra-1,3,5(10)-triene
Donesta
estetrol
estetrol
estetrol
estetrolum
estra-1,3,5(10)-triene-3,15alpha,16alpha,17beta-tetrol
oestetrol
Species
homo sapiens
NCBI:txid9606 Heikkilä, J. and Adlercreutz, H. (1970) A method for the determination of urinary 15α-hydroxyestriol and estriol: Preliminary results of 15α-hydroxyestriol determinations in pregnancy urine. Journal of Steroid Biochemistry, 1(3), 243-253.
Europe PubMed Central results
Characterization of the <i>SWEET</i> Gene Family in Longan (<i>Dimocarpus longan</i>) and the Role of <i>DlSWEET1</i> in Cold Tolerance.
Author: Fang T, Rao Y, Wang M, Li Y, Liu Y, Xiong P, Zeng L.
Abstract: Sugars will eventually be exported transporters (SWEET), a group of relatively novel sugar transporters, that play important roles in phloem loading, seed and fruit development, pollen development, and stress response in plants. Longan (<i>Dimocarpus longan</i>), a subtropic fruit tree with high economic value, is sensitive to cold. However, whether the <i>SWEET</i> gene family plays a role in conferring cold tolerance upon longan remains unknown. Here, a total of 20 longan SWEET (<i>DlSWEET</i>) genes were identified, and their phylogenetic relationships, gene structures, <i>cis</i>-acting elements, and tissue-specific expression patterns were systematically analyzed. This family is divided into four clades. Gene structures and motifs analyses indicated that the majority of <i>DlSWEETs</i> in each clade shared similar exon-intron organization and conserved motifs. Tissue-specific gene expression suggested diverse possible functions for <i>DlSWEET</i> genes. <i>Cis</i>-elements analysis and quantitative real-time PCR (qRT-PCR) analysis revealed that <i>DlSWEET1</i> responded to cold stress. Notably, the overexpression of <i>DlSWEET1</i> improved cold tolerance in transgenic <i>Arabidopsis</i>, suggesting that <i>DlSWEET1</i> might play a positive role in <i>D. longan's</i> responses to cold stress. Together, these results contribute to a better understanding of SWEET genes, which could serve as a foundation for the further functional identification of these genes.
DOI: 10.3390/ijms23168914
Estetrol: a unique steroid in human pregnancy.
Author: Holinka CF, Diczfalusy E, Coelingh Bennink HJ.
Abstract: Estetrol (E(4)) is an estrogenic steroid molecule synthesized exclusively by the fetal liver during human pregnancy and reaching the maternal circulation through the placenta. Its function is presently unknown. After its discovery in the mid-1960s, E(4) research revealed rather unique properties of this steroid and spawned a large body of state-of-the art publications. Nevertheless, 20 years later experimental work was virtually abandoned. In recent years based on new data, E(4) has experienced a vita nova, a revival of preclinical and clinical research activities with the goal to elucidate its physiological function and explore its potential for therapeutic use in humans. This review is intended to offer an historical account of the discovery of E(4) and the preclinical studies conducted during the heyday of E(4) research that ended in the mid-1980s.
Oral bioavailability and bone-sparing effects of estetrol in an osteoporosis model.
Author: Coelingh Bennink HJ, Heegaard AM, Visser M, Holinka CF, Christiansen C.
Abstract: <h4>Objectives</h4>To measure the oral bioavailability of estetrol (E(4)) in rats relative to its subcutaneous administration and to test the bone-sparing effect of oral E(4) compared to that of ethinylestradiol (EE).<h4>Methods</h4>In the bioavailability study, E(4) was administered as a single dose of 0.05, 0.5 or 5.0 mg/kg orally or subcutaneously to female rats. Plasma was analyzed using an LC-MS/MS method. The bone study was conducted in 3-month-old female rats assigned to the following seven treatment groups of ten animals each: no treatment; sham-operated + vehicle; bilaterally ovariectomized (OVX) + vehicle; OVX + E(4) 0.1, 0.5, or 2.5 mg/kg/day and OVX + EE 0.1 mg/kg/day. Once-daily treatment by oral gavage was given for 4 weeks and the following measurements were performed: serum osteocalcin, bone mineral density, bone mineral content and bone mineral area of lumbar vertebrae L3-L6, peripheral quantitative computed tomography of the left tibiae and the biomechanical properties of the distal femora.<h4>Results</h4>Oral bioavailability of E(4), relative to that of subcutaneous dosing, was 70% and above at the 0.05 and 0.5 mg/kg doses based on the AUC(0-t last). Subcutaneous dosing provided significantly higher E(4) levels at the 1-h time point only, and was comparable to oral dosing after 0.5, 2, 4 and 8 h. In the bone study, E(4) dose-dependently and significantly (1) inhibited the OVX-related increase in osteocalcin levels, (2) increased bone mineral density and content, and (3) increased bone strength, all attenuated by ovariectomy. In this rat model, the relative potency of the highest dose of E(4) (2.5 mg/kg/day) was comparable to the EE dose, used as positive control.<h4>Conclusions</h4>Estetrol exhibits high oral bioavailability in the rat, a species considered relevant for pharmacological studies that are predictive for effects on human bone. Oral administration of E(4) conveys dose-dependent bone-sparing effects of high-quality bone in estrogen-depleted OVX rats. Based on its bone-sparing effects, its oral bioavailability and its preclinical safety and efficacy profile, E(4) may be superior to other estrogens and is a potential drug for the prevention of osteoporosis in postmenopausal women.
Estetrol review: profile and potential clinical applications.
Author: Coelingh Bennink HJ, Holinka CF, Diczfalusy E.
Abstract: In this review paper, the existing information on the human fetal steroid estetrol (E4) has been summarized. In the past, E4 was considered as a weak estrogen and interest disappeared. However, recent new research has demonstrated that E4 is a potent, orally bioavailable, natural human fetal selective estrogen receptor modulator, since it acts in the rat as an estrogen on all tissues investigated except breast tumor tissue, where it has estrogen antagonistic properties in the presence of estradiol. Based on its safety data, its pharmacokinetic properties, its pharmacological profile and the results of first human studies, E4 may be suitable as a potential drug for human use in applications such as hormone replacement therapy (vaginal atrophy, hot flushes), contraception and osteoporosis. Additional areas worth exploring are the treatment of breast and prostate cancer, hypoactive sexual desire disorder and topical use (wrinkles) in women, auto-immune diseases, migraine, cardiovascular applications and the treatment of selected obstetric disorders.
Clinical applications for estetrol.
Author: Visser M, Coelingh Bennink HJ.
Abstract: In this paper the potential clinical applications for the human fetal estrogen estetrol (E(4)) are presented based on recently obtained data in preclinical and clinical studies. In the past E(4) has been classified as a weak estrogen due to its rather low estrogen receptor affinity. However, recent research has demonstrated that due to its favorable pharmacokinetic properties, especially the slow elimination and long half-life, E(4) is an effective orally bioavailable estrogen agonist with estrogen antagonistic effects on the breast in the presence of estradiol. Based on the pharmacokinetic properties, the pharmacological profile and the safety and efficacy results in human studies, E(4) seems potentially suitable as a drug for human use in applications such as hormone replacement therapy (vaginal atrophy and vasomotor symptoms), contraception, osteoporosis and breast cancer.
Estetrol, molecular chaperones, and the epigenetics of longevity and cancer resistance.
Author: Krøll J.
Abstract: Evidence is given that replicative senescence--possibly as organismal aging--constitutes epigenetic phenomena, counteracted by homeostatic factors such as, e.g., the molecular chaperones, which are housekeeping molecules essential for the folding, repair, and transport of proteins, RNA, and DNA. Weakening of the chaperone defense with age probably contributes to the frailty in senescence. The present review presents evidence that the human fetal estrogen hormone estetrol, by promotion of chaperone functions, homeostasis, and cancer resistance, may prove useful as a supplement during human senescence.
Estetrol attenuates neonatal hypoxic-ischemic brain injury.
Author: Tskitishvili E, Nisolle M, Munaut C, Pequeux C, Gerard C, Noel A, Foidart JM.
Abstract: Estetrol (E4) is a recently described natural estrogen with four hydroxyl-groups that is synthesized exclusively during pregnancy by the human fetal liver. It has important antioxidative activity. The aim of the present study was to define the importance of E4 in the attenuation of neonatal hypoxic-ischemic encephalopathy. Antioxidative effect of 650μM, 3.25mM and 6.5mM E4 on primary hippocampal cell cultures was studied before/after H202-induced oxidative stress. To examine oxidative stress and cell viability, lactate dehydrogenase activity and cell proliferation colorimetric assays were performed. To study the neuroprotective and therapeutic effects of E4 in vivo neonatal hypoxic-ischemic encephalopathy model of 7-day-old newborn rat pups was used. The neuroprotective and therapeutic effects of estetrol before/after hypoxic-ischemic insult was studied in 1mg/kg/day, 5mg/kg/day, 10mg/kg/day, 50mg/kg/day E4 pretreated/treated groups and compared with the sham and the vehicle treated groups. The body temperature of the rat pups was examined along with their body and brain weights. Brains were studied at the level of the hippocampus and cortex. Intact cell counting and expressions of microtubule-associated protein-2, doublecortin and vascular-endothelial growth factor were evaluated by histo- and immunohistochemistry. ELISAs were performed on blood samples to detect concentrations of S100B and glial fibrillary acidic protein as brain damage markers. This work reveals for the first time that E4 significantly decreases LDH activity and enhances cell proliferation in primary hippocampal neuronal cell cultures in vitro, and decreases the early gray matter loss and promotes neuro- and angiogenesis in vivo.
Estetrol prevents and suppresses mammary tumors induced by DMBA in a rat model.
Author: Visser M, Kloosterboer HJ, Bennink HJ.
Abstract: <h4>Background</h4>Estetrol (E4) is a pregnancy-specific estrogenic steroid hormone produced by the human fetal liver in both male and female fetuses. During pregnancy, E4 plasma values increase exponentially until parturition and decrease thereafter. The synthesis of E4 in the liver of a newborn ceases during the first weeks after birth.<h4>Materials and methods</h4>Here we report the effect of E4 on the initiation and growth of mammary tumors chemically induced by 7,12 dimethylbenz(a)anthracene (DMBA) in female Sprague-Dawley rats in two different protocols. Two prevention studies to test the effect on initiation and growth of induced tumors and one intervention study to test the effect on tumor growth were performed. In the prevention studies, the effect of oral doses of E4 over a dose range of 0.5-3.0 mg/kg was investigated. In the intervention study, oral doses of 1, 3 and 10 mg/kg E4 were used. The anti-estrogen tamoxifen (TAM) and ethinylestradiol (EE) were used as reference compounds. In all studies, a group with ovariectomized animals (OVX) was included.<h4>Results</h4>In the prevention studies, 2.5 mg and 3 mg/kg E4 showed a significant effect on the number and growth of induced tumors by DMBA, and the effects were comparable to those of TAM, whereas EE had no effect. In the intervention study, the effect of a high dose of E4 (10 mg/kg) on tumor number was similar to that of OVX and better than TAM and high-dose EE. The 3 mg/kg E4 had an effect comparable to high-dose EE. The treatment effects were largely due to complete regression of existing tumors.<h4>Conclusions</h4>The natural fetal estrogen E4 prevents tumor initiation by DMBA and inhibits the growth of existing DMBA-induced tumors.
Unique effects on hepatic function, lipid metabolism, bone and growth endocrine parameters of estetrol in combined oral contraceptives.
Author: Mawet M, Maillard C, Klipping C, Zimmerman Y, Foidart JM, Coelingh Bennink HJ.
Abstract: <h4>Objectives</h4>Estetrol (E4) is a natural estrogen produced by the human fetal liver. In combination with drospirenone (DRSP) or levonorgestrel (LNG), E4 blocks ovulation and has less effect on haemostatic biomarkers in comparison with ethinylestradiol (EE) combined with DRSP. This study evaluates the impact of several doses of E4/DRSP and E4/LNG on safety parameters such as liver function, lipid metabolism, bone markers and growth endocrine parameters.<h4>Methods</h4>This was a dose-finding, single-centre, controlled study performed in healthy women aged 18 to 35 years with a documented pretreatment ovulatory cycle. Participants received 5 mg or 10 mg E4/3 mg DRSP; 5 mg, 10 mg or 20 mg E4/150 μg LNG; or 20 μg EE/3 mg DRSP as a comparator for three consecutive cycles in a 24/4-day regimen. Changes from baseline to end of treatment in liver parameters, lipid metabolism, bone markers and growth endocrinology were evaluated.<h4>Results</h4>A total of 109 women were included in the study. Carrier proteins were minimally affected in the E4/DRSP and E4/LNG groups, in comparison with the EE/DRSP group, where a significant increase in sex hormone-binding globulin was observed. Similarly, minor effects on lipoproteins were observed in the E4 groups, and the effects on triglycerides elicited by the E4 groups were significantly lower than those in the EE/DRSP group. No imbalances in bone markers were observed in any groups. No alterations in insulin-like growth factor were observed in the E4 groups.<h4>Conclusions</h4>E4-containing combinations have a limited effect on liver function, lipid metabolism, and bone and growth endocrine parameters.
Estrogen receptors and estetrol-dependent neuroprotective actions: a pilot study.
Author: Tskitishvili E, Pequeux C, Munaut C, Viellevoye R, Nisolle M, Noël A, Foidart JM.
Abstract: Estetrol (E4) has strong antioxidative, neurogenic and angiogenic effects in neural system resulting in the attenuation of neonatal hypoxic-ischemic encephalopathy. We aimed to define the role of estrogen receptors in E4-dependent actions in neuronal cell cultures and prove the promyelinating effect of E4. In vitro the antioxidative and cell survival/proliferating effects of E4 on H<sub>2</sub>O<sub>2</sub>-induced oxidative stress in primary hippocampal cell cultures were studied using different combinations of specific inhibitors for ERα (MPP dihydrochloride), ERβ (PHTTP), GPR30 (G15) and palmytoilation (2-BR). LDH activity and cell survival assays were performed. In vivo the promyelinating role of different concentrations of E4 (1 mg/kg/day, 5 mg/kg/day, 10 mg/kg/day, 50 mg/kg/day) was investigated using the hypoxic-ischemic brain damage model in the 7-day-old immature rats before/after the induction of hypoxic-ischemic insult. Myelin basic protein (MBP) immunostaining was performed on brain coronal sections. Our results show that LDH activity is significantly upregulated in cell cultures where the E4's effect was completely blocked by concomitant treatment either with ERα and ERβ inhibitors (MPP and PHTPP, respectively), or ERα and ERβ inhibitors combined with 2-BR. Cell survival is significantly downregulated in cell cultures where the effect of E4 was blocked by ERβ inhibitor (PHTTP) alone. The blockage of GRP30 receptor did affect neither LDH activity nor cell survival. MBP immunostaining is significantly upregulated in E4-pretreated groups at a concentration of 5 mg/kg/day and 50 mg/kg/day E4, whereas the MBP-positive area OD ratio is significantly increased in all the E4-treated groups. E4's antioxidative actions mostly depend on ERα and ERβ, whereas neurogenesis and possibly promyelinating activities might be realized through ERβ.
DOI: 10.1530/joe-16-0434
Pharmacokinetics of the fetal estrogen estetrol in a multiple-rising-dose study in postmenopausal women.
Author: Coelingh Bennink HJT, Verhoeven C, Zimmerman Y, Visser M, Foidart JM, Gemzell-Danielsson K.
Abstract: <h4>Objectives</h4>Estetrol (E4) is a natural fetal estrogen. In this open-label, multiple-rising-dose study, the pharmacokinetic effects of E4 in postmenopausal women were investigated as a secondary objective.<h4>Methods</h4>In total, 49 postmenopausal women were randomized to receive either 2 mg E4 or 2 mg estradiol valerate (E2V) for 28 days, or were (non-randomized) assigned to 10, 20, or 40 mg E4. The main outcome measures were: E4 plasma concentrations at trough, and on days 1 and 28; and E4 pharmacokinetic parameters AUC, C<sub>max</sub> and t<sub>max</sub> on days 1 and 28.<h4>Results</h4>After oral administration, E4 showed a very fast absorption, followed by a multiphasic elimination with an initial rapid decline, gradually continuing with a slower elimination, suggesting a long terminal half-life. Steady state was reached within 2 weeks of dosing and pharmacokinetic results were generally proportional to the dose. Estetrol concentrations on day 28 were slightly higher compared to day 1, indicating some accumulation.<h4>Conclusion</h4>The pharmacokinetic profile of estetrol is characterized by a very fast absorption phase, followed by an initial rapid decline, and a slow terminal elimination phase. Based on its kinetic properties, estetrol seems suitable for use as a once-daily oral drug.
Regulatory effects of estetrol on the endothelial plasminogen pathway and endothelial cell migration.
Author: Montt-Guevara MM, Palla G, Spina S, Bernacchi G, Cecchi E, Campelo AE, Shortrede JE, Canu A, Simoncini T.
Abstract: <h4>Background</h4>Estetrol (E4) is a natural estrogen produced solely during human pregnancy. E4 is suitable for clinical use since it acts as a selective estrogen receptor modulator. In clinical trials E4 has been seen to have little or no effect on coagulation. Hence, it is interesting to investigate whether E4 alters endothelial-dependent fibrinolysis.<h4>Objectives</h4>We studied the effects of E4 on the fibrinolytic system and whether this could influence the ability of endothelial cells to migrate. In addition, we compared the effects of E4 with those of 17β-estradiol (E2).<h4>Study design</h4>Human umbilical vein endothelial cells (HUVEC) were obtained from healthy women. Expression of plasminogen-activator inhibitor-1 (PAI-1), urokinase-type plasminogen activator (u-PA) and tissue plasminogen activator (t-PA) proteins was evaluated by Western blot analysis. Endothelial cell migration was studied by razor-scrape horizontal and multiwell insert systems assays.<h4>Results</h4>E4 increased the expression of t-PA, u-PA and PAI-1 in HUVEC, but less so than did equimolar amounts of E2. The effects of E4 on t-PA, u-PA and PAI-1 were mediated by the induction of the early-immediate genes c-Jun and c-Fos. E4 in combination with E2 antagonized the effects induced by pregnancy-like E2 concentrations but did not impair the effects of postmenopausal-like E2 levels. We also found that the increased synthesis of PAI-1, u-PA and t-PA induced by E2 and E4 is important for horizontal and three-dimensional migration of HUVEC.<h4>Conclusions</h4>These results support the hypothesis that E4 acts as an endogenous selective estrogen receptor modulator (SERM), controlling the fibrinolytic system and endothelial cell migration.
Whole blood microsampling for the quantitation of estetrol without derivatization by liquid chromatography-tandem mass spectrometry.
Author: Nys G, Gallez A, Kok MGM, Cobraiville G, Servais AC, Piel G, Pequeux C, Fillet M.
Abstract: Quantitative bioanalysis and especially pharmacokinetic studies are challenging since only low volumes of biological material are available and low concentrations (ng/ml) are often expected. In this context, volumetric absorptive microsampling (VAMS) devices were developed to accurately collect 10 or 20μl of whole blood from tested subjects. In this study, we present the development and validation of ultra-high performance liquid chromatography coupled to tandem mass spectrometry method after VAMS sampling for the quantitation of estetrol (E4), a potentially new medicine for hormone replacement, contraception and osteoporosis therapies. Interestingly, a very simple sample preparation procedure was developed without any derivatization step. Even if lack of sensitivity is a common consideration when using negative ionization mode, we demonstrated in this work that an excellent sensitivity could be reached by carefully optimizing the nature and concentration of the mobile phase additive. After the optimization of every experimental parameter, the stability, selectivity, trueness, precision and accuracy of the final method were successfully demonstrated. In addition, the excellent performances of the method were confirmed by two independent proof-of-concept pharmacokinetic studies of E4 after VAMS collection in a murine model.
Estetrol combined with drospirenone: an oral contraceptive with high acceptability, user satisfaction, well-being and favourable body weight control.
Author: Apter D, Zimmerman Y, Beekman L, Mawet M, Maillard C, Foidart JM, Coelingh Bennink HJT.
Abstract: <h4>Objectives</h4>This study evaluated acceptability, user satisfaction, body weight control and general well-being of estetrol (E4) combined with either drospirenone (DRSP) or levonorgestrel (LNG).<h4>Methods</h4>In this open-label, multi-centre, dose-finding, 6-cycle study, 396 healthy women of reproductive age were randomised into five treatment groups in a 24/4-day regimen: 15 mg or 20 mg E4 combined with either 3 mg DRSP or 150 μg LNG, and as reference estradiol valerate (E2V) combined with dienogest (DNG). Data on acceptability, user well-being, satisfaction and body weight were collected.<h4>Results</h4>The number of completers was the highest in the 15 mg E4/DRSP group (91.1%), and the lowest for 20 mg E4/LNG (70.1%). The largest proportion of treatment satisfaction was reported for 15 mg E4/DRSP (73.1%), and the lowest for 15 mg E4/LNG (50.6%). The number of women willing to continue with the assigned study treatment was the highest in the 15 mg E4/DRSP group (82.1%) and the lowest for 20 mg E4/LNG (58.3%). Well-being with E4/DRSP combinations was statistically significantly better than with E4/LNG combinations: OR (95% CI) 2.00 (1.13; 3.53) and 1.93 (1.06; 3.56) for 15 and 20 mg E4, respectively, and comparable to E2V/DNG. Proportion of women with a 2 kg or more weight loss after 3 and 6 cycles was the highest in the 15 mg E4/DRSP group (30.7 and 36.7%, respectively).<h4>Conclusions</h4>The present study shows that 15 mg estetrol combined with 3 mg DRSP is associated with a high-user acceptability and satisfaction, and with a favourable body weight control.
Estetrol, a Fetal Selective Estrogen Receptor Modulator, Acts on the Vagina of Mice through Nuclear Estrogen Receptor α Activation.
Author: Benoit T, Valera MC, Fontaine C, Buscato M, Lenfant F, Raymond-Letron I, Tremollieres F, Soulie M, Foidart JM, Game X, Arnal JF.
Abstract: The genitourinary syndrome of menopause has a negative impact on quality of life of postmenopausal women. The treatment of vulvovaginal atrophy includes administration of estrogens. However, oral estrogen treatment is controversial because of its potential risks on venous thrombosis and breast cancer. Estetrol (E4) is a natural estrogen synthesized exclusively during pregnancy by the human fetal liver and initially considered as a weak estrogen. However, E4 was recently evaluated in phase 1 to 2 clinical studies and found to act as an oral contraceptive in combination with a progestin, without increasing the level of coagulation factors. We recently showed that E4 stimulates uterine epithelial proliferation through nuclear estrogen receptor (ER) α, but failed to elicit endothelial responses. Herein, we first evaluated the morphological and functional impacts of E4 on the vagina of ovariectomized mice, and we determined the molecular mechanism mediating these effects. Vaginal epithelial proliferation and lubrication after stimulation were found to increase after E4 chronic treatment. Using a combination of pharmacological and genetic approaches, we demonstrated that these E4 effects on the vagina are mediated by nuclear ERα activation. Altogether, we demonstrate that the selective activation of nuclear ERα is both necessary and sufficient to elicit functional and structural effects on the vagina, and therefore E4 appears promising as a therapeutic option to improve vulvovaginal atrophy.
Effect of estetrol, a selective nuclear estrogen receptor modulator, in mouse models of arterial and venous thrombosis.
Author: Valéra MC, Noirrit-Esclassan E, Dupuis M, Fontaine C, Lenfant F, Briaux A, Cabou C, Garcia C, Lairez O, Foidart JM, Payrastre B, Arnal JF.
Abstract: Estetrol (E4) is a natural estrogen synthesized exclusively during pregnancy by the human fetal liver, and the physiological role of this hormone is unknown. Interestingly, E4 was recently evaluated in preclinical and phase II-III clinical studies in combination with a progestin, with the advantage to not increase the circulating level of coagulation factors, at variance to oral estradiol or ethinylestradiol. Here, we evaluated the effect of E4 on hemostasis and thrombosis in mouse. Following chronic E4 treatment, mice exhibited a prolonged tail-bleeding time and were protected from arterial and also venous thrombosis in vivo. In addition, E4 treatment decreased ex vivo thrombus growth on collagen under arterial flow conditions. We recently showed that E4 activates uterine epithelial proliferation through nuclear estrogen receptor (ER) α. To analyze the impact of nuclear ERα actions on hemostasis and thrombosis, we generated hematopoietic chimera with bone marrow cells deficient for nuclear ERα. E4-induced protection against thromboembolism was significantly reduced in the absence of hematopoietic nuclear ERα activation, while the increased tail-bleeding time was not impacted by this deletion. In addition to its "liver friendly" profile described in women, our data shows that E4 has anti-thrombotic properties in various mouse models. Altogether, the natural fetal estrogen E4 could represent an attractive alternative to classic estrogens in oral contraception and treatment of menopause.
A Dose-Escalating Study With the Fetal Estrogen Estetrol in Healthy Men.
Author: Coelingh Bennink HJT, Zimmerman Y, Verhoeven C, Dutman AE, Mensinga T, Kluft C, Reisman Y, Debruyne FMJ.
Abstract: <h4>Context</h4>Luteinizing hormone-releasing hormone (LHRH) agonists have replaced estrogens for endocrine treatment of advanced prostate cancer (PC) because of cardiovascular side effects. The fetal estrogen estetrol (E4) may be safer for PC treatment and is expected to decrease testosterone (T) and prevent estrogen deficiency.<h4>Objective</h4>To investigate the safety and T-suppressive effect of E4 in healthy men.<h4>Design</h4>Double-blind, randomized, placebo-controlled, dose-escalating study.<h4>Setting</h4>The study was conducted at a phase I clinical unit (QPS, Netherlands).<h4>Participants</h4>Healthy male volunteers aged 40 to 70 years.<h4>Intervention(s)</h4>Three treatment cohorts of 15 volunteers with placebo (n = 5) and E4 (n = 10). Estetrol doses tested were 20, 40, and 60 mg/d. Subjects were treated for 4 weeks.<h4>Main outcome measures</h4>Subjective side effects, pharmacodynamic effects on hemostatic variables, lipids, glucose, bone parameters, and endocrine parameters related to T metabolism.<h4>Results</h4>Total and free T decreased dose-dependently and significantly. Nipple tenderness occurred in 40% and decrease of libido occurred in 30% of E4-treated men. The unwanted estrogenic effects on hemostasis were small, dose dependent, and in some cases significant. Lipid and bone parameters showed a favorable trend.<h4>Conclusion</h4>The effect of E4 on testosterone levels is insufficient for standalone PC treatment. Taking all clinical and pharmacodynamic variables into consideration, a daily dose of 40 mg E4 seems safe for further evaluation of endocrine PC treatment in combination with LHRH analogs.
Development of injectable liposomes and drug-in-cyclodextrin-in-liposome formulations encapsulating estetrol to prevent cerebral ischemia of premature babies.
Author: Palazzo C, Laloy J, Delvigne AS, Nys G, Fillet M, Dogne JM, Pequeux C, Foidart JM, Evrard B, Piel G.
Abstract: NA
Rapid and simultaneous measurement of estrone, estradiol, estriol and estetrol in serum by high performance liquid chromatography with electrochemical detection.
Author: Hayashi N, Hayata K, Sekiba K.
Abstract: A high performance liquid chromatographic (HPLC) method with electrochemical detection (ECD) was developed for the simultaneous measurement of estrone, estradiol, estriol and estetrol in serum. These hormones were extracted with diethylether, chromatographed on an silica-octadecyl silane (ODS) column with an eluent of phosphate buffer solution-acetonitrile-methanol (volume ratio 152:85:40), and detected by ECD at +1.0V vs. Ag/AgCl. In comparisons between the values measured by this method and radioimmunoassay, significant correlations were noted for estrone (r = 0.759, p less than 0.01), estradiol (r = 0.816, p less than 0.001) and estriol (r = 0.830, p less than 0.001). In clinical applications of this method, differences between cases of the normal and the anencephalic pregnancy in the thirty-eighth week of gestation were distinct not only in the individual estrogen, but also in the profile analysis of estrogens. With this method, all 4 serum estrogens above approximately 500 pg/ml could be measured within 2 h, and the method seemed to be clinically applicable.
DOI: 10.18926/amo/31517
The Persian Gulf War: Israeli medical experience and perspectives.
Author: NA
Abstract: NA