Potential hazards to embryo implantation: A human endometrial in vitro model to identify unwanted antigestagenic actions of chemicals.

Embryo implantation is a crucial step in human reproduction and depends on the timely development of a receptive endometrium. The human endometrium is unique among adult tissues due to its dynamic alterations during each menstrual cycle. It hosts the implantation process which is governed by progesterone, whereas 17ß-estradiol regulates the preceding proliferation of the endometrium. The receptors for both steroids are targets for drugs and endocrine disrupting chemicals. Chemicals with unwanted antigestagenic actions are potentially hazardous to embryo implantation since many pharmaceutical antiprogestins adversely affect endometrial receptivity. This risk can be addressed by human tissue-specific in vitro assays. As working basis we compiled data on chemicals interacting with the PR. In our experimental work, we developed a flexible in vitro model based on human endometrial Ishikawa cells. Effects of antiprogestin compounds on pre-selected target genes were characterized by sigmoidal concentration-response curves obtained by RT-qPCR. The estrogen sulfotransferase (SULT1E1) was identified as the most responsive target gene by microarray analysis. The agonistic effect of progesterone on SULT1E1 mRNA was concentration-dependently antagonized by RU486 (mifepristone) and ZK137316 and, with lower potency, by 4-nonylphenol, bisphenol A and apigenin. The negative control methyl acetoacetate showed no effect. The effects of progesterone and RU486 were confirmed on the protein level by Western blotting. We demonstrated proof of principle that our Ishikawa model is suitable to study quantitatively effects of antiprogestin-like chemicals on endometrial target genes in comparison to pharmaceutical reference compounds. This test is useful for hazard identification and may contribute to reduce animal studies.

Estrogen replacement therapy after endometrial cancer: a survey of physicians' prescribing practice.

OBJECTIVE: To determine whether the prescribing practice of physicians with regard to estrogen replacement therapy (ERT) in symptomatic women with previous endometrial cancer is consistent with the available evidence. METHODS: A descriptive survey was conducted among physicians in Germany, using a questionnaire containing two hypothetical cases of endometrial cancer patients ('low-risk' and 'high-risk' disease) and menopausal symptoms. Physicians were asked about their prescribing practice concerning moderate to severe menopausal symptoms. RESULTS: Four hundred and twenty questionnaires were sent out, with an overall response rate of 39.8%; 45.6% in the 'low-risk' case and 75.4% in the 'high-risk' case (p < 0.0001) stated that ERT is contraindicated. Only 12.9% were willing to prescribe ERT; 81.9% preferred to prescribe non-estrogenic alternatives (44.8% phytoestrogens, 29.0% selective serotonin reuptake inhibitors). CONCLUSION: Despite the evidence that ERT does not increase the risk of recurrence of endometrial cancer, many physicians are reluctant to prescribe ERT in women suffering from moderate to severe menopausal symptoms.

Therapeutic options for postmenopausal female sexual dysfunction.

BACKGROUND: Female sexual dysfunction (FSD) is a multidimensional problem combining biological, psychological and interpersonal elements of multiple etiologies. Menopause-related sexual dysfunction may not be reversible without therapy. Hormonal deficiency does not usually decrease in severity over time. Many options are available for the successful treatment of postmenopausal FSD. OBJECTIVE: To review the pharmacological and non-pharmacological therapies available for postmenopausal FSD, focusing on practical recommendations for managing postmenopausal women with sexual complaints, through a literature review of the most relevant publications in this field. PSYCHOSOCIAL THERAPY: This type of therapy (basic counselling, physiotherapy and psychosexual intervention) is considered an adaptable step-by-step approach for diagnostic and therapeutic strategies, normally combined with biomedical interventions to provide optimal outcomes. PHARMACOLOGICAL THERAPY: For postmenopausal FSD, many interventional options are now available, including hormonal therapies such as estrogens, testosterone, combined estrogen/testosterone, tibolone and dehydroepiandrosterone. CONCLUSIONS: Menopause and its transition represent significant risk factors for the development of sexual dysfunction. FSD impacts greatly on a patient's quality of life. Consequently, it is receiving more attention thanks to the development of effective treatments. Non-pharmacological approaches should be used first, focusing on lifestyle and psychosexual therapy. If required, proven effective hormonal and non-hormonal therapeutic options are available.

Low density lipoprotein (LDL) subfractions during pregnancy: accumulation of buoyant LDL with advancing gestation.

Pregnancy is accompanied by changes in the maternal lipoprotein metabolism that may serve to satisfy the nutritional demands of the fetus. In this study lipoprotein metabolism was investigated in 23 women during normal pregnancy in the first, second, and third trimesters and in 15 healthy nonpregnant women with regular menstrual cycles. Lipid and apolipoprotein concentrations were measured in total plasma, very low density, intermediate density, low density (LDL), and high density lipoproteins, and in each of six LDL subfractions. During early pregnancy, triglycerides, and dense LDL were higher than in the nonpregnant state. With advancing gestation, triglycerides increased and the distribution of apolipoprotein B-100-containing lipoproteins became increasingly dominated by the accumulation of very low density and intermediate density lipoproteins and buoyant, triglyceride-rich LDL. This is the first study that investigates LDL subfractions in pregnancy using a method that strictly separates LDL subfractions by virtue of density. The accumulation of buoyant, triglyceride-rich lipoproteins may be related to the down-regulation of maternal lipase activities by placental hormones. As a consequence, the metabolic changes of late pregnancy may result in an increased flux of lipoprotein-derived lipids to the placenta, which, with advancing gestation, increasingly expresses receptors with a high affinity for triglyceride-rich lipoproteins.

Formation of proinflammatory cytokines in human term myometrium is stimulated by lipopolysaccharide but not by corticotropin-releasing hormone.

Human term myometrium is poorly characterized as a source of proinflammatory mediators involved in parturition. We have investigated the basal expression of cytokines in myometrium, as well as the effects of CRH and lipopolysaccharide (LPS) on cytokine release. Explants from term myometrium were challenged with CRH or LPS (1 microg/mL each) in short-term tissue culture. Interleukin (IL)-1beta++, IL-6, IL-8, and tumor necrosis factor (TNF)alpha concentrations in the medium were quantified by enzyme immunoassay. The major cytokines released after 24 h were IL-6 and IL-8. All cytokines investigated were stimulated significantly by LPS (P: < 0. 05) but not by CRH. Messenger RNA levels of these cytokines were investigated by RT-PCR. IL-1beta+ and IL-6 messenger RNA were present in preterm and term myometrium before and during labor, whereas IL-8 and TNFalpha were expressed only by myometrium in active labor. Furthermore, myometrial CRH receptors and macrophages were characterized immunohistochemically. We conclude that human term myometrium is a site of production of proinflammatory cytokines and is involved in the inflammation-like reactions mediating the birth process. Cytokine release in term myometrium seems not to be under control of CRH.

mRNA expression profiles for corticotrophin-releasing hormone, urocortin, CRH-binding protein and CRH receptors in human term gestational tissues determined by real-time quantitative RT-PCR.

Increasing maternal plasma levels of corticotrophin-releasing hormone (CRH) during the last weeks of pregnancy suggest that this stress hormone plays an important role in the control of human parturition. Little is known about the quantitative contribution of gestational tissues (other than placenta) to intrauterine formation of CRH, urocortin and CRH-binding protein (CRH-BP), or about the distribution of CRH receptors within the uterus. We have investigated the mRNA expression of CRH, urocortin, CRH-BP and CRH receptors 1 and 2 (CRH-R1 and -R2) in gestational tissues by real-time RT-PCR. Placenta, myometrium and choriodecidua were collected after uncomplicated pregnancies at term, before the onset of labour. Distribution of CRH-R1 and CRH-R2 protein was also investigated by immunostaining with receptor subtype-specific antibodies. The placenta was identified as the main site of CRH and CRH-BP mRNA expression, displaying mRNA levels >1000 and >20 times higher than those found in the myometrium and choriodecidua respectively (P<0.05 in each case). mRNA expression of urocortin was low in all tissues investigated. Myometrium and choriodecidua expressed relevant amounts of both receptor subtypes, whereas the CRH receptor population in placenta consisted mainly of CRH-R2. The high expression of CRH in placenta and the substantial expression of CRH receptors in choriodecidua and myometrium suggested that CRH derived from placenta exerts direct or indirect actions on these tissues. Neither CRH produced by myometrium or choriodecidua nor urocortin from other intrauterine sources seem to play a major role in the control of labour.

Analgesics during pregnancy.

The thalidomide tragedy of the late 1950s clearly proved the need for caution, and questionable drug use should always be avoided. The teratogenic potential of a drug is related to dosage and time of administration. During blastogenesis, fetal death may occur; during embryogenesis, deformity may develop; and during the last trimester, functional anomalies or "covert embryopathy" may be seen. Finally, the benefit to risk ratio of every drug must be carefully weighed, and only those with proved safety to the feto-maternal unit should be prescribed. Aspirin may be administered to the pregnant woman as an anti-inflammatory agent but in the lowest therapeutic dosage. In the later stages of pregnancy, however, aspirin should be avoided since it may prolong labor, lead to greater blood loss during delivery, and increase the incidence of stillbirths. The pyrazolones, although not associated with teratogenic side effects, may lead to sometimes fatal agranulocytosis and, accordingly, are not recommended in pregnancy. Acetaminophen is the analgesic and antipyretic of choice during all phases of pregnancy.

Arachidonate metabolism in human placenta, fetal membranes, decidua and myometrium: lipoxygenase and cytochrome P450 metabolites as main products in HPLC profiles.

Eicosanoids play a key role in pregnancy maintenance and parturition. We investigated the metabolism of arachidonic acid (AA) in short-term tissue cultures of placenta, fetal membranes, decidua and myometrium. Tissues were obtained from caesarean sections before the onset of labour after uncomplicated pregnancies. The released metabolites were analysed by high performance liquid chromatography (HPLC) and specific immunoassays. In radiotracer experiments tissues were labelled with [3H]-AA and metabolites released after incubation with calcium ionophore A23187 were profiled by HPLC. Decidua was more active in metabolizing AA (turnover 34 per cent) than myometrium (28 per cent), placenta (21 per cent) and fetal membranes (17 per cent). Main product in placenta, decidua and myometrium was 12-hydroxyeicosatetraeinoic (12-HETE) (decidua: 19 per cent of released radioactivity, myometrium 14 per cent, placenta 7 per cent). Fetal membranes formed 5-HETE as main product. Another major metabolite in placenta, fetal membranes and decidua was characterized by HPLC as 5(6)-epoxyeicosatrienoic acid. Only myometrium released appreciable amounts of prostaglandins in form of 6-keto-prostaglandin F1 alpha. In non-radioactive experiments formation of eicosanoids from endogenous AA was investigated by HPLC (fluorescence- and UV-detection) and immunoassays. These experiments confirmed the high production of 12-HETE and the low formation of prostaglandins. Our results suggest that the biological role of AA-metabolites, other than prostaglandins, have as yet been underestimated.

Immunohistochemical localization of thromboxane synthase in human intrauterine tissues.

Uterine tissues are known to be able to synthesize thromboxane A2 (TXA2), but there is little information about the nature of cells actually responsible for its production. In this study human placenta, fetal membranes, umbilical cord and pregnant myometrium were investigated immunohistochemically. The avidin-biotin method for a monoclonal antibody against human thromboxane synthase (Tü 300) was applied on frozen tissue sections. In placenta, fetal membranes and umbilical cord, staining was positive for Hofbauer cells and fibroblasts. Further, in sections of placenta, capillary endothelium showed antigenicity for TX synthase. Leiomyocytes in the umbilical cord vessels contained the enzyme as well. Preparations of pregnant myometrium were shown to express TX synthase in leiomyocytes, endothelial cells and connective tissue cells. Amnion, trophoblast and decidua did not possess antigenicity for this enzyme. Since TXA2 plays an important role for the regulation of vascular tone and aggregation of platelets and may stimulate myometrial contractions during parturition, the abundance of TX synthase in pregnancy-specific tissues confirms previous in vivo and in vitro observations. Further, TXA2 synthesized by Hofbauer cells may be involved in immunological reactions during pregnancy, and the number and level of activation of Hofbauer cells may be closely related to the initiation of labour. Thromboxane production by the endothelium lining the fetal vessels points to its regulatory role for the blood flow in the fetoplacental unit.

Expression of prostacyclin and thromboxane synthases in placenta and placental bed after pre-eclamptic pregnancies.

Prostacyclin and thromboxane are potent antagonistic regulators of vascular tone and platelet aggregation. In pre-eclampsia, the ratio of their metabolites is decreased. Little is known about the local regulation of intrauterine prostacyclin and thromboxane production in this condition. Placenta and placental bed biopsies were obtained from uncomplicated and pre-eclamptic pregnancies. Prostacyclin synthase (PCS) and thromboxane synthase (TXS) and their mRNA's were localized by immunohistochemistry using monoclonal antibodies and in situ hybridization. Protein and mRNA levels were quantified by immunoblot and RNase protection assay. PCS-like immunoreactivity was found in endothelial cells and leiomyocytes, whereas fetal and maternal macrophages showed positive staining for TXS. Their mRNA was localized to trophoblast and endothelium, and TXS mRNA could also be detected in macrophages. Quantitative analysis showed no significant difference in intrauterine protein or mRNA expression after pre-eclampsia. The prostacyclin and thromboxane production seems to be compartmentalized within the uteroplacental unit. The expression of their synthesizing enzymes might be regulated post-transcriptionally. Additional regulation of prostaglandin production could be metabolically or on the substrate level and requires further elucidation.

Eicosanoid production by frozen tissue in vitro is markedly changed.

The influence of storing deep frozen human tissue specimens on their eicosanoid production in tissue culture was evaluated. Pieces of placenta and fetal membranes (n = 6) were divided and part processed immediately after obtaining the tissues, part after being kept at -20 degrees C for some days. Eicosanoid production was studied in tissue culture with incubation in oxygenated Hank's balanced salt solution (HBSS) at 37 degrees C for 1 h. Prostaglandin E2 (PGE2), prostacyclin (PGI2), thromboxane A2 (TXA2) and leukotriene B4 (LTB4) production were significantly different in the tissues frozen prior to the incubation. This should be considered when interpreting eicosanoid synthesis in tissue cultures for their significance in vivo.

The effect of clomiphene on the synthesis of prostaglandins (PGF2 alpha, PGE2, PGI2) in human endometrial cells in vitro with and without addition of estradiol-17 beta or progesterone.

The production of prostaglandin F2 alpha in monolayer stromal cell cultures of proliferative human endometrium is enhanced by 10(-7) mol/l estradiol-17 beta or 10(-4) mol/l progesterone. Progesterone in high concentration (10(-4) mol/l) also enhanced the synthesis of prostaglandin E2. Clomiphene citrate reduced this increased prostaglandin production dose dependently. The synthesis of prostaglandin I2 was not influenced either by sex steroids or by clomiphene citrate.

Characterization and identification of cytochrome P450 metabolites of arachidonic acid released by human peritoneal macrophages obtained from the pouch of Douglas.

Cytochrome P450 metabolism of arachidonic acid (AA) was investigated in human peritoneal macrophages which play a central role in chronic pelvic diseases in women (for example in endometriosis). The formation of eicosanoids other than prostaglandins (PGs) by these cells is still unknown. In non-activated macrophages obtained from women in the reproductive age, the main [(3)H]-AA metabolites coeluted with epoxyeicosatrienoic acids, dihydroxyeicosatrienoic acids (DHETs) and hydroxyeicosatetraenoic acids (HETEs) in reverse-phase HPLC. After zymosan activation a shift to PGs pathway was observed. Treatment with low doses of 2,3,7,8-tetrachlorodibenzo- p -dioxin increased the formation of a metabolite coeluting with 5,6-DHET. By gas chromatography/mass spectrometry 5,6-DHET (after beta-naphthoflavone induction), and 14,15-DHET as well as 11,12-DHET (after AA stimulation) were identified as major epoxygenase metabolites, respectively. The enantioselective formation of 12(S)-HETE was demonstrated by chiral-phase HPLC. Our findings demonstrate that non-activated peritoneal macrophages produce substantial amounts of bioactive cytochrome P450 metabolites of AA.

Experience with leuprorelin acetate depot in the treatment of fibroids: a German multicentre study.

Between October 1988 and October 1990 in a noncomparative multicentre study, 114 patients were treated for uterine fibroids with the gonadotrophin-releasing hormone (Gn-RH) agonist, leuprorelin acetate depot. The mean age of the women was 33 years and 55.3% of them had a history of infertility. After confirmation of the diagnosis by ultrasound and/or operation, treatment began between day 1 and 3 of the cycle with leuprorelin acetate depot 3.75 mg subcutaneously. Therapy was carried out for a total of 6 months with one injection every 4 weeks. Treatment was paralleled by measurements of endocrine and metabolic parameters, estimation of myoma and uterine size by ultrasound and self-reporting of the patients of drug-related complaints. Four of the 114 women did not complete the whole treatment, two of them because of general side effects, one because of carcinophobia and unsatisfactory regression of the myoma and the last one for unspecified reasons. During treatment, a mean reduction of the uterine volume of about 67% was observed, in conjunction with shrinkage of the myoma in 92.1% of cases (mean decrease of 56% of the fibroids) with a large interindividual difference. Maximal diminution of uterine and fibroid size had been nearly completely reached within the first 12 weeks of therapy. After 4 weeks of the Gn-RH agonist depot most of the patients had achieved postmenopausal status, which continued throughout the remaining 20 weeks of treatment. In accordance with this finding, the majority of general side effects was due to the hypo-oestrogenic endocrine status. Liver and lipid metabolism was almost unaffected, although increasing calcium and alkaline phosphatase serum levels as well as an increased urinary calcium/creatinine ratio demonstrated an increased metabolic turnover of the bone. Haemoglobin concentrations, however, increased in those cases with fibroid-related anaemia. Thus the slow-release form of leuprorelin acetate is an adjunct to myomectomy especially in those women in whom family planning is not yet completed.

Exposure of human endometrium to environmental estrogens, antiandrogens, and organochlorine compounds.

OBJECTIVE: To determine concentrations of environmental estrogens, antiandrogens, and organochlorine compounds in human endometrium and body fat. DESIGN: Cross-sectional, population-based study. SETTING: Patient recruitment was done at a university hospital; chemical analysis was performed in a specialized private laboratory. PATIENT(S): Premenopausal, unexposed women undergoing hysterectomy for uterine myoma. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Concentrations of environmental modulators in human endometrium and body fat were quantified by high-resolution gas chromatography/high-resolution mass spectrometry. RESULT(S): Among known endocrine modulators, the antiandrogenic p, p'-dichlorodiphenyl-dichloroethylene was found in the highest concentrations in endometrium (median 4.7 microg/kg wet weight) and body fat (median 446 microg/kg wet weight). Only trace amounts of the identified environmental estrogens beta-hexachlorocyclohexane, o, p'-dichlorodiphenyl-trichloroethane, bisphenol A, hydroxylated polychlorinated biphenyls, and genistein were found in the endometrium (median <1 microg/kg wet weight). As major organochlorine contaminants without endocrine activities, polychlorinated biphenyls and hexachlorobenzene were found. CONCLUSION(S): Our data demonstrate that nonchlorinated environmental estrogens do not build up cumulative tissue concentrations in the endometrium. The risk of reduced fertility because of ambient levels of environmental estrogens in the endometrium is negligible.

Expression patterns of CRH, CRH receptors, and CRH binding protein in human gestational tissue at term.

Recent research suggests a significant role for placental corticotropin-releasing hormone (CRH) in controlling human parturition. This paper describes the expression of CRH, CRH receptors 1 and 2, and CRH binding protein (CRH-BP) in gestational tissue in late pregnancy. Placenta, myometrium, decidua, and fetal membranes were collected after uncomplicated pregnancies at term caesarian section before the onset of labour. The localisation and mRNA expression of CRH, CRH receptors, and CRH-BP were studied by immunohistochemistry and reverse transcription (RT)-PCR. CRH receptors were detected in placenta, myometrium, decidua, and fetal membranes. We demonstrated for the first time the presence of CRH receptors on resident macrophages and on endothelial cells. CRH receptor 1 mRNA was detected in all tissues investigated by RT-PCR, whereas CRH receptor 2 mRNA was restricted to myometrium and decidua. CRH mRNA was widely expressed in all tissue under study. Novel findings are also presented on the expression of CRH-BP in the myometrium. This widespread expression of the CRH system in gestational tissue suggests a paracrine role for CRH in the birth process (e.g. effects on macrophages and endothelial cells).

Efficacy and safety of the new antiandrogenic oral contraceptive Belara.

The aim of this open, noncontrolled phase III study was the assessment of the contraceptive efficacy and the evaluation of the safety of long-term use of Belara (30 micrograms ethinyl estradiol plus 2 mg chlormadinone acetate). Furthermore, cycle stability during administration of Belara and the influence of Belara on acne and seborrhea as clinical signs of androgenization were observed. Belara was taken by 1655 women for a total of 22,337 cycles. For the theoretical Pearl index, a value of 0.269 (95% CI [0.109, 0.600]) was calculated. In 1655 of 22,337 cycles (7.4%), no withdrawal bleeding was documented, whereas in 2565 of 22,308 cycles (11.5%), spottings and, in 786 of 22,308 cycles (3.5%), breakthrough bleeding occurred. After the intake of Belara for 12 cycles, acne on the face/neck improved in 64.1% of the women (209 of 326). In 53.4% of the women (175 of 326), acne disappeared completely. Seborrhea improved after 12 cycles in 89 of 131 women (67.9%), of whom 76 women (58.0%) were completely cured. Sixty-two serious adverse events (SAE) occurred in 59 of 1655 women. Accidents and injuries of the musculoskeletal system were the SAE with the highest incidence (0.66%). Two cases of deep venous thrombosis, one pulmonary embolism, and two cases of visual disturbances were observed. Only for the two cases of deep venous thrombosis could a relation to Belara be assumed. Of the adverse events commonly reported for oral contraceptives, headache was observed for the first time under study medication in 37.4%, nausea in 23.1%, breast tenderness in 21.7%, and vaginal discharge in 19.4% of the women. The frequency of adverse events decreased with longer duration of a drug consisting of intake of Belara. In conclusion, Belara can be described as an effective and safe oral contraceptive with marked antiandrogenic properties.

PIP: The contraceptive safety and efficacy of long-term use of the oral contraceptive Belara (30 mcg ethinyl estradiol and 2 mg chlormadinone acetate) were assessed in an open, noncontrolled phase III study. Of particular interest was the effect of the anti-androgenic activity of this formulation on clinical signs of androgenization. Belara was taken by 1655 German women (mean age, 25.9 years), for a total of 22,337 cycles. A total of 12 pregnancies occurred, yielding a theoretical Pearl index of 0.269 (95% confidence interval, 0.109-0.600). No withdrawal bleeding occurred in 1655 cycles (7.4%), while spotting was documented in 2565 (11.5%) and breakthrough bleeding in 786 (3.5%). After 12 cycles of use, acne on the face/neck improved in 64.1% of affected women and completely disappeared in 53.4%. Seborrhea improved after 12 cycles in 67.9% of affected women and was cured in 58.0%. Side effects included headache (37.4%), nausea (23.1%), breast tenderness (21.7%), and vaginal discharge (19.4%). Of the 62 serious adverse events reported by 59 women, only the 2 cases of deep venous thrombosis could be linked to Belara use. Overall, these findings suggest that Belara is a well-tolerated oral contraceptive with minor side effects comparable to those associated with use of other low-dose pills.

[Drug therapy of dysmenorrhea]. / Die medikamentöse Therapie der Dysmenorrhoe.

PIP: Primary dysmenorrhea occurs mostly in young women with a painful bleeding pattern. In a recent study, 72% of 19-year-old women had light, 19% had medium to severe, and 8% had severe symptoms. Secondary dysmenorrhea means pathological organic alterations of the genital tract: uterus myomatosus, endometrial polyps, endometriosis, and retroflexed uterus. IUDs can also generate this condition. A certain imbalance of estradiol and progesterone results in defective prostaglandin formation in the endometrium (too much PGF2alpha and too little PGI2) as well as in abnormal and increased uterine contractility and diminished endometrial, blood supply with concomitant painful ischemia. Increased prostaglandin synthesis leads to inflammatory processes and the traumatization of the endometrium (high PGF2alpha level), but IUDs also often cause secondary dysmenorrhea. Treatment calls for the normalization of prostaglandin formation in the uterus by dietary change by increasing fatty acid intake (fish oils and plant fats), and also by the systematic addition of exogenic gestagens (Duphaston 10 mg/day po. Orgametril 5 mg/day), and by the use of the progesterone-releasing IUDs (Biograviplan and Progestasert) that lessen the contractility of the myometrium by reducing PGF2-alpha synthesis. If pregnancy is to be avoided hormonal ovulation inhibitors as optimal, since their effectiveness is over 90% (Cilest, Femovan, Marvelon, and Ortho-Novum 2 mg). If contraception is not sought, nonsteroidal antiphlogistics are recommended: ibuprofen (400 mg 3-4 times/day), naproxen (250 mg 4-5 times/day), flufenamic acid (200 mg/day tid), mefenamic acid (500 mg 3 tid or 250 mg qid), aspirin (650 mg every 4-6 hours), indomethacin (25 mg tid, although it is relatively toxic). Magnesium is a natural calcium antagonist that can influence the intracellular calcium concentration in the myometrium. THe calcium blocker nifedipin (20-40 mg po) and beta-sympathomimetics (Partusisten) also mitigate uterine contractions, but the latter can produce more side effects as a consequence of interfering in the vegetative nervous system.^ieng

In vitro-Ishikawa cell test for assessing tissue-specific chemical effects on human endometrium.

The human endometrium is a fertility-determining factor. Its receptivity during the implantation window may be altered by chemicals. Since human embryo implantation is unique chemical risk assessment cannot be based solely on animal studies. We established a tissue-specific in vitro test based on human endometrial adenocarcinoma (Ishikawa) cells. Progesterone receptor (PR) was selected as primary target gene for estrogenic effects. Changes of mRNA levels were investigated by reverse transcription quantitative real-time PCR. Sigmoidal dose-response curves for up-regulation of PR mRNA and EC(50) values were established for 17beta-estradiol, diethylstilbestrol and the weak xenoestrogen bisphenol A. Nonylphenol also had a clear PR mRNA up-regulating effect. Several other chemicals were characterized as negative compounds. Among them was methoxyacetic acid which may produce false positive results in reporter gene assays. Up-regulation of PR protein by 17beta-estradiol, diethylstilbestrol, bisphenol A and nonylphenol was confirmed by Western Blotting.