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Infertility is a growing issue in society today, affecting 15% of reproductive aged couples globally. Alongside this decrease in fertility, we are also seeing a global decline in overall reproductive health, with many reproductive disorders becoming more common. This decline in fertility and reproductive health can be largely attributed to our continuous exposure to chemicals in our environment known as endocrine disrupting chemicals (EDCs). Diethylstilbestrol (DES) is an estrogenic EDC, and provides one of the best examples of the detrimental effects prenatal EDC exposure can have on reproductive development and adult onset disease. DES is a pharmaceutical drug that was prescribed to millions of pregnant women world wide in the mistaken belief that it helped prevent miscarriage and premature labour, however, lead to extensive reproductive effects in the offspring exposed. Specifically, women who were exposed to DES in utero experience higher rates of infertility, pregnancy complications and reproductive cancers. Alarmingly, there is evidence to suggest that DES may promote transgenerational disease, with effects persisting in the grandchildren and great grandchildren of exposed women. Through the use of the mouse model, this thesis investigates the transgenerational effect of DES on female fertility and reproductive health and furthermore, investigates the mechanisms through which DES is able to promote transgenerational disease. Firstly, the many phenotypic effects of DES were described in F1 to F3 female descendants. Prenatal exposure to DES altered fertility indices, litter size, oocytes ovulated, timing of puberty, anogenital distance (AGD) and body weight, with fertility index, pregnancy rate, puberty onset and AGD being impacted in a transgenerational manner. Next, to determine the mechanisms through which DES is able to promote this observed infertility, the transgenerational effect of DES on ovarian development was investigated. DES exposure caused a subtle

Tussen de jaren 1940 en 1970 maakte het DES-hormoon, dat werd toegediend aan zwangere vrouwen om miskramen te voorkomen, wereldwijd miljoenen slachtoffers. Toch blijft het DES-probleem in België tot op heden onder de radar. Aan de hand van interviews met DES-slachtoffers en artsen toont Antje Van Kerckhove aan hoe die onwetendheid verklaard kan worden.

Endocrine disrupting chemicals (EDCs) can interfere with normal hormonal action and regulation. Exposure of women to EDCs has been associated with adverse reproductive health outcomes. The assays currently used to identify EDCs that elicit female reproductive toxicity lack screening tests that address effects on the maturation of oocytes, a process that enables them to be fertilized and develop into embryos. Here, a screening method employing the bovine model of in vitro oocyte maturation and embryo production is described. Endpoints explored address important events in oocyte maturation and developmental competence acquisition. To test the method, the effects of the known human EDC diethylstilbestrol (DES; an estrogen receptor agonist) were evaluated in a range of concentrations (10 -9 M, 10 -7 M, 10 -5 M). Bovine oocytes were exposed to DES during in vitro maturation (IVM) or embryos were exposed during in vitro embryo culture (IVC). The endpoints evaluated included nuclear maturation, mitochondrial redistribution, cumulus cell expansion, apoptosis, and steroidogenesis. DES-exposed oocytes were fertilized to record embryo cleavage and blastocyst rates to uncover effects on developmental competence. Similarly, the development of embryos exposed to DES during IVC was monitored to assess the impact on early embryo development. Exposure to 10 -9 M or 10 -7 M DES did not affect the endpoints addressing oocyte maturation or embryo development. However, there were considerable detrimental effects observed in oocytes exposed to 10 -5 M DES. Specifically, compared to vehicle-treated oocytes, there was a statistically significant reduction in nuclear maturation (3% vs 84%), cumulus expansion (2.8-fold vs 3.6-fold) and blastocyst rate (3% vs 32%). Additionally, progesterone and pregnenolone concentrations measured in IVM culture media were increased. The screening method described here shows that bovine oocytes were sensitive to the action of this particular chemical (i.e

The present study investigated the developmental toxicity of diethylstilbestrol (DES) in the zebrafish embryotoxicity test (ZET). This was done to investigate whether the ZET would better capture the developmental toxicity of DES than the embryonic stem cells test (EST) that was previously shown to underpredict the DES-induced developmental toxicity as compared to in vivo data, potentially because the EST does not capture late events in the developmental process. The ZET results showed DES-induced growth retardation, cumulative mortality and dysmorphisms (i.e. induction of pericardial edema) in zebrafish embryos while the endogenous ERα agonist 17β-estradiol (E2) showed only growth retardation and cumulative mortality with lower potency compared to DES. Furthermore, the DES-induced pericardial edema formation in zebrafish embryos could be counteracted by co-exposure with ERα antagonist fulvestrant, indicating that the ZET captures the role of ERα in the mode of action underlying the developmental toxicity of DES. Altogether, it is concluded that the ZET differentiates DES from E2 with respect to their developmental toxicity effects, while confirming the role of ERα in mediating the developmental toxicity of DES. Furthermore, comparison to in vivo data revealed that, like the EST, in a quantitative way also the ZET did not capture the relatively high in vivo potency of DES as a developmental toxicant.

Diethylstilbestrol (DES) is a synthetic estrogen and proven human teratogen and carcinogen reported to act via the estrogen receptor α (ERα). Since the endogenous ERα ligand 17β-estradiol (E2) does not show these adverse effects to a similar extent, we hypothesized that DES’ interaction with the ERα differs from that of E2. The current study aimed to investigate possible differences between DES and E2 using in vitro assays that detect ERα-mediated effects, including ERα-mediated reporter gene expression, ERα-mediated breast cancer cell (T47D) proliferation and ERα-coregulator interactions and gene expression in T47D cells. Results obtained indicate that DES and E2 activate ERα-mediated reporter gene transcription and T47D cell proliferation in a similar way. However, significant differences between DES- and E2-induced binding of the ERα to 15 coregulator motifs and in transcriptomic signatures obtained in the T47D cells were observed. It is concluded that differences observed in binding of the ERα with several co-repressor motifs, in downregulation of genes involved in histone deacetylation and DNA methylation and in upregulation of CYP26A1 and CYP26B1 contribute to the differential effects reported for DES and E2.

In the present study, we evaluated an alternative testing strategy to quantitatively predict the in vivo developmental toxicity of the synthetic hormone diethylstilbestrol (DES). To this end, a physiologically based kinetic (PBK) model was defined that was subsequently used to translate concentration–response data for the in vitro developmental toxicity of DES, obtained in the ES-D3 cell differentiation assay, into predicted in vivo dose–response data for developmental toxicity. The previous studies showed that the PBK model-facilitated reverse dosimetry approach is a useful approach to quantitatively predict the developmental toxicity of several developmental toxins. The results obtained in the present study show that the PBK model adequately predicted DES blood concentrations in rats. Further studies revealed that DES tested positive in the ES-D3 differentiation assay and that DES-induced inhibition of the ES-D3 cell differentiation could be counteracted by the estrogen receptor alpha (ERα) antagonist fulvestrant, indicating that the in vitro ES-D3 cell differentiation assay was able to mimic the role of ERα reported in the mode of action underlying the developmental toxicity of DES in vivo. In spite of this, combining these in vitro data with the PBK model did not adequately predict the in vivo developmental toxicity of DES in a quantitative way. It is concluded that although the EST qualifies DES as a developmental toxin and detects the role of ERα in this process, the ES-D3 cell differentiation assay of the EST apparently does not adequately capture the processes underlying DES-induced developmental toxicity in vivo.

Hormoni su organska jedinjenja različite hemijske prirode koji svojim dejstvom utiču na rast, funkciju i metabolizam organizma. Povišene koncentracije hormona dovode do stvaranja slobodnih radikala, što može izazvati oksidativni stres i oštećenja DNK molekula. Poznato je da komponente tradicionalne mediteranske ishrane imaju pozitivne efekte na smanjenje oksidativnog stresa i prevenciju mnogih bolesti. Brojne in vitro i in vivo studije su potvrdile korisne efekte suvog ekstrakta lista masline (DOLE) i njegovih sastojaka, kao i zaštitni potencijal u odnosu na oksidativna oštećenja DNK molekula. Stoga, glavni cilj ove doktorske disertacije je bio da se ispita antigenotoksični potencijal spektra koncentracija suvog ekstrakta lista masline u leukocitima periferne krvi čoveka u prisustvu hormona tiroksina, adrenalina, estradiola i dietilstilbestrola in vitro. Ispitivanje je obavljeno primenom alkalnog komet testa, osetljive i brze metode za određivanje i analizu primarnih oštećenja DNK u pojedinačnim ćelijama. Rezultati ove studije su pokazali da su tiroksin, adrenalin, estradiol i dietilstibestrol sposobni da budu medijatori značajnog povećanja oštećenja DNK molekula. Suvi ekstrakt lista masline je u svim testiranim koncentracijama ispoljio značajan antigenotoksični potencijal u oba eksperimentalna protokola, u pretretmanu i posttretmanu. Praćenje kinetike reparacije DNK u prisustvu DOLE u odnosu na oštećenja izazvana hormonima je pokazalo da ekstrakt nije značajno uticao na stimulaciju reparacije oštećenja DNK. Sumirajući rezultate ove disertacije, može se zaključiti da suvi ekstrakt lista masline poseduje izražen potencijal smanjenja primarnih oštećenja DNK izazvanih tiroksinom, adrenalinom, estradiolom i dietilstilbestrolom. Predstavljeni in vitro model na leukocitima periferne krvi čoveka pružio je podatke koji su korisni za buduće in vivo studije i klinička ispitivanja suvog ekstrakta lista masline., Hormones are organic compounds of different chemical nature that affect cell growth, function and metabolism. Elevated concentrations of hormones lead to the formation of free radicals, which can cause oxidative stress and damage to the DNA molecule. It is known that the components of traditional Mediterranean food have positive effects on the reduction of oxidative stress and the prevention of many diseases. Numerous in vitro and in vivo studies have confirmed the beneficial effects of dry olive leaf extract (DOLE) and its constituents, as well as protective potential on the oxidative damage of DNA molecules. Therefore, the main aim of this doctoral dissertation was to investigate the antigenotoxic potential of the spectrum of concentrations of dry olive leaf extract in peripheral blood leukocytes in the presence of hormone thyroxine, adrenaline, estradiol, and diethylstilbestrol in vitro. The study was performed using an alkaline comet assay, a sensitive and fast method for determining and analyzing primary DNA damage in individual cells. The results of this study have shown that thyroxine, adrenaline, estradiol, and diethylstibestrol are capable of being mediators of significant increase of DNA damage. Dry olive leaf extract demonstrated significant ability to reduce primary DNA damage at all tested concentrations and in both experimental protocols, in pretreatment and posttreatment. Monitoring the kinetics of DNA repair in the presence of DOLE in relation to damage induced by homones has shown that the extract did not significantly affect the stimulation of DNA damage repair. Summarizing the results of this dissertation, it can be concluded that the dry olive leaf extract possesses a strong potential to reduce primary DNA damage induced by thyroxine, adrenaline, estradiol, and diethylstilbestrol. The presented in vitro model on human peripheral blood leukocytes provided data that are useful for future in vivo studies and clinical trials of dry olive leaf extract

Hormoni su organska jedinjenja različite hemijske prirode koji svojim dejstvom utiču na rast, funkciju i metabolizam organizma. Povišene koncentracije hormona dovode do stvaranja slobodnih radikala, što može izazvati oksidativni stres i oštećenja DNK molekula. Poznato je da komponente tradicionalne mediteranske ishrane imaju pozitivne efekte na smanjenje oksidativnog stresa i prevenciju mnogih bolesti. Brojne in vitro i in vivo studije su potvrdile korisne efekte suvog ekstrakta lista masline (DOLE) i njegovih sastojaka, kao i zaštitni potencijal u odnosu na oksidativna oštećenja DNK molekula. Stoga, glavni cilj ove doktorske disertacije je bio da se ispita antigenotoksični potencijal spektra koncentracija suvog ekstrakta lista masline u leukocitima periferne krvi čoveka u prisustvu hormona tiroksina, adrenalina, estradiola i dietilstilbestrola in vitro. Ispitivanje je obavljeno primenom alkalnog komet testa, osetljive i brze metode za određivanje i analizu primarnih oštećenja DNK u pojedinačnim ćelijama. Rezultati ove studije su pokazali da su tiroksin, adrenalin, estradiol i dietilstibestrol sposobni da budu medijatori značajnog povećanja oštećenja DNK molekula. Suvi ekstrakt lista masline je u svim testiranim koncentracijama ispoljio značajan antigenotoksični potencijal u oba eksperimentalna protokola, u pretretmanu i posttretmanu. Praćenje kinetike reparacije DNK u prisustvu DOLE u odnosu na oštećenja izazvana hormonima je pokazalo da ekstrakt nije značajno uticao na stimulaciju reparacije oštećenja DNK. Sumirajući rezultate ove disertacije, može se zaključiti da suvi ekstrakt lista masline poseduje izražen potencijal smanjenja primarnih oštećenja DNK izazvanih tiroksinom, adrenalinom, estradiolom i dietilstilbestrolom. Predstavljeni in vitro model na leukocitima periferne krvi čoveka pružio je podatke koji su korisni za buduće in vivo studije i klinička ispitivanja suvog ekstrakta lista masline., Hormones are organic compounds of different chemical nature that affect cell growth, function and metabolism. Elevated concentrations of hormones lead to the formation of free radicals, which can cause oxidative stress and damage to the DNA molecule. It is known that the components of traditional Mediterranean food have positive effects on the reduction of oxidative stress and the prevention of many diseases. Numerous in vitro and in vivo studies have confirmed the beneficial effects of dry olive leaf extract (DOLE) and its constituents, as well as protective potential on the oxidative damage of DNA molecules. Therefore, the main aim of this doctoral dissertation was to investigate the antigenotoxic potential of the spectrum of concentrations of dry olive leaf extract in peripheral blood leukocytes in the presence of hormone thyroxine, adrenaline, estradiol, and diethylstilbestrol in vitro. The study was performed using an alkaline comet assay, a sensitive and fast method for determining and analyzing primary DNA damage in individual cells. The results of this study have shown that thyroxine, adrenaline, estradiol, and diethylstibestrol are capable of being mediators of significant increase of DNA damage. Dry olive leaf extract demonstrated significant ability to reduce primary DNA damage at all tested concentrations and in both experimental protocols, in pretreatment and posttreatment. Monitoring the kinetics of DNA repair in the presence of DOLE in relation to damage induced by homones has shown that the extract did not significantly affect the stimulation of DNA damage repair. Summarizing the results of this dissertation, it can be concluded that the dry olive leaf extract possesses a strong potential to reduce primary DNA damage induced by thyroxine, adrenaline, estradiol, and diethylstilbestrol. The presented in vitro model on human peripheral blood leukocytes provided data that are useful for future in vivo studies and clinical trials of dry olive leaf extract

The role of tissue interactions was explored to determine whether epithelial differentiation within the developing human reproductive tract is induced and specified by mesenchyme in tissue recombinants composed of mouse vaginal mesenchyme + human uterine tubal epithelium (mVgM+hTubE). The tissue recombinants were grown in DES-treated ovariectomized athymic mice. After 2-4 weeks of in vivo growth, several vaginal specific features were expressed in the human tubal epithelium. The mesenchyme-induced effects included morphological change as well as expression of several immunohistochemical markers. Although the mesenchyme-induced shift in vaginal differentiation in the human tubal epithelium was not complete, the partial induction of vaginal markers in human tubal epithelium verifies the importance of mesenchymal-epithelial interactions in development of the human female reproductive tract. In a separate experiment, DES-induction of uterine epithelial progesterone receptor (PGR) and estrogen receptor 1 (ESR1) was explored in tissue recombinants composed of wild-type or Esr1KO mouse uterine mesenchyme + human fetal uterine epithelium (wt UtM+hUtE and Esr1KO UtM+hUtE). The rationale of this experiment was to determine whether DES-induction of PGR and ESR1 is mediated directly via epithelial ESR1 or indirectly (paracrine mechanism) via mesenchymal ESR1. DES-induction of uterine epithelial ESR1 and PGR in Esr1KO UtM+hUtE tissue recombinants (devoid of mesenchymal ESR1) formally eliminates the paracrine mechanism and demonstrates that DES induction of human uterine epithelial ESR1 and PGR is directly mediated via epithelial ESR1.

The role of tissue interactions was explored to determine whether epithelial differentiation within the developing human reproductive tract is induced and specified by mesenchyme in tissue recombinants composed of mouse vaginal mesenchyme + human uterine tubal epithelium (mVgM+hTubE). The tissue recombinants were grown in DES-treated ovariectomized athymic mice. After 2-4 weeks of in vivo growth, several vaginal specific features were expressed in the human tubal epithelium. The mesenchyme-induced effects included morphological change as well as expression of several immunohistochemical markers. Although the mesenchyme-induced shift in vaginal differentiation in the human tubal epithelium was not complete, the partial induction of vaginal markers in human tubal epithelium verifies the importance of mesenchymal-epithelial interactions in development of the human female reproductive tract. In a separate experiment, DES-induction of uterine epithelial progesterone receptor (PGR) and estrogen receptor 1 (ESR1) was explored in tissue recombinants composed of wild-type or Esr1KO mouse uterine mesenchyme + human fetal uterine epithelium (wt UtM+hUtE and Esr1KO UtM+hUtE). The rationale of this experiment was to determine whether DES-induction of PGR and ESR1 is mediated directly via epithelial ESR1 or indirectly (paracrine mechanism) via mesenchymal ESR1. DES-induction of uterine epithelial ESR1 and PGR in Esr1KO UtM+hUtE tissue recombinants (devoid of mesenchymal ESR1) formally eliminates the paracrine mechanism and demonstrates that DES induction of human uterine epithelial ESR1 and PGR is directly mediated via epithelial ESR1.

Objective: Women exposed to diethylstilbestrol in utero (DES) have an increased risk of clear cell adenocarcinoma (CCA) of the vagina and cervix, while their risk of non-CCA invasive cervical cancer is still unclear. Methods: We studied the risk of pre-cancerous (CIN) lesions and non-CCA invasive cervical cancer in a prospective cohort of 12,182 women with self-reported DES exposure followed from 2000 till 2008. We took screening behavior carefully into account. Incidence was obtained through linkage with the Netherlands Nationwide Pathology database (PALGA). General population data were also derived from PALGA. Results: The incidence of CIN1 was increased (Standardized Incidence Ratio (SIR). =2.8, 95% Confidence Interval (CI). =2.3 to 3.4), but no increased risk was observed for CIN2. + (CIN2, CIN3 or invasive cancer) compared to the screened general population (SIR. =1.1, 95% CI. =0.95 to1.4). Women with DES-related malformations had increased risks of both CIN1 and CIN2. + (SIR. =4.1, 95%CI. =3.0 to 5.3 and SIR. =1.5, 95%CI. =1.1 to 2.0, respectively). For CIN2. +, this risk increase was largely restricted to women with malformations who were more intensively screened. Conclusions: An increased risk of CIN1 among DES daughters was obse

This review presents published and novel results that define the programming window for diethylstilbestrol (DES)-induced abnormal development of the mouse penis. These data indicate that DES has its greatest effect during the period of most intense penile morphogenesis, namely postnatal days 0-15 (P0-P15). Pregnant mice and their neonatal pups were injected subcutaneously with 200 ng/gbw DES every other day from embryonic day 12-18 (DES E12-E18), postnatal day 0-10 (DES P0-P10), embryonic day 12 to postnatal day 10 (DES E12-P10), postnatal day 5-15 (DES P5-P15), and postnatal day 10-20 (DES P10-P20). Aged-matched controls received sesame oil vehicle. After euthanasia at 10, 15, 20 and 60 days, penises were analyzed by gross morphology, histology and morphometry. Penises of all 5 groups of DES-treated mice were reduced in size, which was confirmed by morphometric analysis of internal penile structures. The most profound effects were seen in the DES E12-P10, DES P0-P10, and DES P5-P15 groups, thus defining a DES "programming window". For all parameters, DES treatment from P10 to P20 showed the most mild of effects. Adverse effects of DES on the MUMP cartilage and erectile bodies observed shortly after the last DES injection reverted to normality in the DES P5-P15, but not in the E12-P10 and P0-P10 groups, in which MUMP cartilage and erectile body malformations persisted into adulthood, again emphasizing a "window of susceptibility" in the early neonatal period.

Uterine fibroids have always been the prime medical issue for females, especially the ones travelling in their reproductive age ( 20-35), with some studies reporting 20-80% of women developing fibroids by the

This review presents published and novel results that define the programming window for diethylstilbestrol (DES)-induced abnormal development of the mouse penis. These data indicate that DES has its greatest effect during the period of most intense penile morphogenesis, namely postnatal days 0-15 (P0-P15). Pregnant mice and their neonatal pups were injected subcutaneously with 200 ng/gbw DES every other day from embryonic day 12-18 (DES E12-E18), postnatal day 0-10 (DES P0-P10), embryonic day 12 to postnatal day 10 (DES E12-P10), postnatal day 5-15 (DES P5-P15), and postnatal day 10-20 (DES P10-P20). Aged-matched controls received sesame oil vehicle. After euthanasia at 10, 15, 20 and 60 days, penises were analyzed by gross morphology, histology and morphometry. Penises of all 5 groups of DES-treated mice were reduced in size, which was confirmed by morphometric analysis of internal penile structures. The most profound effects were seen in the DES E12-P10, DES P0-P10, and DES P5-P15 groups, thus defining a DES "programming window". For all parameters, DES treatment from P10 to P20 showed the most mild of effects. Adverse effects of DES on the MUMP cartilage and erectile bodies observed shortly after the last DES injection reverted to normality in the DES P5-P15, but not in the E12-P10 and P0-P10 groups, in which MUMP cartilage and erectile body malformations persisted into adulthood, again emphasizing a "window of susceptibility" in the early neonatal period.

Uterine fibroids have always been the prime medical issue for females, especially the ones travelling in their reproductive age ( 20-35), with some studies reporting 20-80% of women developing fibroids by the

Uterine fibroids have always been the prime medical issue for females, especially the ones travelling in their reproductive age ( 20-35), with some studies reporting 20-80% of women developing fibroids by the

In the EU collaborative project ChemScreen an alternative, in vitro assay-based test strategy was developed to screen compounds for reproductive toxicity. A toxicokinetic modeling approach was used to allow quantitative comparison between effective concentrations in the in vitro test battery and observations of developmental toxicity in vivo. This modeling strategy is based on (1) the definition of relevant observations of toxicity in vivo, (2) simulation of the corresponding systemic concentrations in vivo by toxicokinetic modeling, and (3) correction for differences in protein binding and lipid partitioning between plasma and in vitro test media. The test results of a feasibility study with a number of known reproductive toxicants has been described previously (Piersma et al. [15]). In the present paper, we take a more detailed look at the toxicokinetics of these compounds, and add the analysis of some compounds from subsequent studies. We discuss how the consideration of toxicokinetics allowed comparison between test systems with differing test medium composition, has helped to interpret the in vitro findings in light of in vivo observations, and to gain confidence in the predictive value of the test battery outcomes. The same toxicokinetic modeling strategy, in reverse order, can now be used for risk assessment purposes to predict toxic doses in vivo from effective concentrations in vitro. © 2014 Elsevier Inc..

Potential trans-generational influence of diethylstilbestrol (DES) exposure emerged with reports of effects in grandchildren of DES-treated pregnant women and of reproductive tract tumors in offspring of mice exposed in utero to DES. Accordingly, we examined the trans-generational influence of DES on development of external genitalia (ExG) and compared effects of in utero DES exposure in CD-1 and C57BL/6 mice injected with oil or DES every other day from gestational days 12 to 18. Mice were examined at birth, and on 5-120 days postnatal to evaluate ExG malformations. Of 23 adult (>60 days) prenatally DES-exposed males, features indicative of urethral meatal hypospadias (see text for definitions) ranged from 18% to 100% in prenatally DES-exposed CD-1 males and 31% to 100% in prenatally DES-exposed C57BL/6 males. Thus, the strains differed only slightly in the incidence of male urethral hypospadias. Ninety-one percent of DES-exposed CD-1 females and 100% of DES-exposed C57BL/6 females had urethral-vaginal fistula. All DES-exposed CD-1 and C57BL/6 females lacked an os clitoris. None of the prenatally oil-treated CD-1 and C57BL/6 male and female mice had ExG malformations. For the second-generation study, 10 adult CD-1 males and females, from oil- and DES-exposed groups, respectively, were paired with untreated CD-1 mice for 30 days, and their offspring evaluated for ExG malformations. None of the F1 DES-treated females were fertile. Nine of 10 prenatally DES-exposed CD-1 males sired offspring with untreated females, producing 55 male and 42 female pups. Of the F2 DES-lineage adult males, 20% had exposed urethral flaps, a criterion of urethral meatal hypospadias. Five of 42 (11.9%) F2 DES lineage females had urethral-vaginal fistula. In contrast, all F2 oil-lineage males and all oil-lineage females were normal. Thus, prenatal DES exposure induces malformations of ExG in both sexes and strains of mice, and certain malformations are transmitted to the second-generation

Potential trans-generational influence of diethylstilbestrol (DES) exposure emerged with reports of effects in grandchildren of DES-treated pregnant women and of reproductive tract tumors in offspring of mice exposed in utero to DES. Accordingly, we examined the trans-generational influence of DES on development of external genitalia (ExG) and compared effects of in utero DES exposure in CD-1 and C57BL/6 mice injected with oil or DES every other day from gestational days 12 to 18. Mice were examined at birth, and on 5-120 days postnatal to evaluate ExG malformations. Of 23 adult (>60 days) prenatally DES-exposed males, features indicative of urethral meatal hypospadias (see text for definitions) ranged from 18% to 100% in prenatally DES-exposed CD-1 males and 31% to 100% in prenatally DES-exposed C57BL/6 males. Thus, the strains differed only slightly in the incidence of male urethral hypospadias. Ninety-one percent of DES-exposed CD-1 females and 100% of DES-exposed C57BL/6 females had urethral-vaginal fistula. All DES-exposed CD-1 and C57BL/6 females lacked an os clitoris. None of the prenatally oil-treated CD-1 and C57BL/6 male and female mice had ExG malformations. For the second-generation study, 10 adult CD-1 males and females, from oil- and DES-exposed groups, respectively, were paired with untreated CD-1 mice for 30 days, and their offspring evaluated for ExG malformations. None of the F1 DES-treated females were fertile. Nine of 10 prenatally DES-exposed CD-1 males sired offspring with untreated females, producing 55 male and 42 female pups. Of the F2 DES-lineage adult males, 20% had exposed urethral flaps, a criterion of urethral meatal hypospadias. Five of 42 (11.9%) F2 DES lineage females had urethral-vaginal fistula. In contrast, all F2 oil-lineage males and all oil-lineage females were normal. Thus, prenatal DES exposure induces malformations of ExG in both sexes and strains of mice, and certain malformations are transmitted to the second-generation

Semen quality is said to have been declining over the past 50 years. The biological significance of these changes is emphasized by a concomitant increase in the incidence of genitourinary abnormalities such as testicular cancer and cryptorchidism. The increase in regional frequency of testicular abnormalities over a relatively short period of time may be due to local environmental factors, including the comparatively recent fashion for wearing tight-fitting underwear. Data also indicates that prenatal exposure to environmental agents can affect the development of the male genital tract. From the reproductive point of view, an increased environmental impact on the human male gonad is of concern and merits the development of sensitive techniques that can detect deleterious agents.

Semen quality is said to have been declining over the past 50 years. The biological significance of these changes is emphasized by a concomitant increase in the incidence of genitourinary abnormalities such as testicular cancer and cryptorchidism. The increase in regional frequency of testicular abnormalities over a relatively short period of time may be due to local environmental factors, including the comparatively recent fashion for wearing tight-fitting underwear. Data also indicates that prenatal exposure to environmental agents can affect the development of the male genital tract. From the reproductive point of view, an increased environmental impact on the human male gonad is of concern and merits the development of sensitive techniques that can detect deleterious agents.

Endogenous lectins act as effectors of cellular activities such as growth regulation, migration, and adhesion. Following their immunohistochemical localization in our previous study (Saussez et al. in Histochem Cell Biol 123:29-41, 2005) we purified several galectins and used them as tools for monitoring accessible binding sites. Herein, we report the use of galectin histochemistry for the analysis of diethylstilbestrol (DES)-induced renal tumors in male Syrian hamster kidney (SHKT). Sections of normal kidney and DES-treated kidney were analyzed with biotinylated galectins-1, -3 (full-length and truncated), and -7. Accessible binding sites were detected, localization was predominantly extracellular and confined to medium-sized and large tumors. Monitoring the SHKT-derived HKT-1097 line, processed in vitro or as xenograft material, cytoplasmic and nuclear staining for galectins-1, -3, and -3tr could be observed. Adaptation of SHKT cells to long-term growth in culture is thus associated with emergence of this signal. Our data set illustrates the feasibility to complement immunohistochemical data by application of the tissue lectins as probes, and to detect regulation of galectin reactivity with differential characteristics within tumor progression in vivo and unique features of the tumor cell line in vitro and in vivo., Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

Endogenous lectins act as effectors of cellular activities such as growth regulation, migration, and adhesion. Following their immunohistochemical localization in our previous study (Saussez et al. in Histochem Cell Biol 123:29-41, 2005) we purified several galectins and used them as tools for monitoring accessible binding sites. Herein, we report the use of galectin histochemistry for the analysis of diethylstilbestrol (DES)-induced renal tumors in male Syrian hamster kidney (SHKT). Sections of normal kidney and DES-treated kidney were analyzed with biotinylated galectins-1, -3 (full-length and truncated), and -7. Accessible binding sites were detected, localization was predominantly extracellular and confined to medium-sized and large tumors. Monitoring the SHKT-derived HKT-1097 line, processed in vitro or as xenograft material, cytoplasmic and nuclear staining for galectins-1, -3, and -3tr could be observed. Adaptation of SHKT cells to long-term growth in culture is thus associated with emergence of this signal. Our data set illustrates the feasibility to complement immunohistochemical data by application of the tissue lectins as probes, and to detect regulation of galectin reactivity with differential characteristics within tumor progression in vivo and unique features of the tumor cell line in vitro and in vivo., Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

To identify key regulatory mechanisms in the growth and development of the human endometrium, microarray analysis was performed on uncultured human endometrium collected during menstruation (M) and the late-proliferative (LATE-P)-phase of the menstrual cycle, as well as after 24 h incubation in the presence of oestradiol (17beta-E2). We demonstrate the expression of novel gene transcripts in the human endometrium. i.e. mucin-9, novel oestrogen-responsive gene transcripts, i.e. gelsolin and flotillin-1, and genes known to be expressed in human endometrium but not yet shown to be oestrogen responsive, i.e. connexin-37 and TFF1/pS2. Genes reported to be expressed during the implantation window and implicated in progesterone action, i.e. secretoglobin family 2A, member 2 (mammaglobin) and homeobox-containing proteins, were up-regulated in uncultured LATE-P-phase endometrium compared to M-phase endometrium. Some gene transcripts are regulated directly by 17beta-E2 alone, others are influenced by the in vivo environment as well. These observations emphasise that the regulation of endometrium maturation by oestrogen entails more then just stimulation of cell proliferation.

The current study focused on galectins (-1, -3, -4, -7, and -8) and deliberately performed immunohistochemical fingerprinting to explore their complexity in a context of experimental renal carcinogenesis. The diethylstilbestrol (DES)-induced renal tumors in male Syrian hamster kidney (SHKT) represent a unique animal model for the study of estrogen-dependent renal malignancies. Kidney sections of DES-treated hamsters (3 days to 11 months of DES exposure) were analyzed by immunohistochemistry using a panel of non-crossreactive antibodies raised against galectins-1, -3, -4, -7, and -8. Levels of expression were quantitatively determined by using computer-assisted microscopy on immunostained tissue sections. Except for galectin-4, all above mentioned galectins were expressed in kidney tumors. Small clusters of galectin-1-positive, most likely preneoplastic cells at the corticomedullary junction were already evident 1 week after DES administration. Galectin-1 and -3 expression was apparently associated with the first steps of the neoplastic transformation, because small tumorous buds were found to be positive after 1 month of treatment. In contrast, galectins-7 and -8 were detected in large tumors and medium-sized tumors, respectively, thereby indicating an involvement in later stages of DES-induced SHKT. Galectins-1, -3, -7, and -8 were also detected by immunofluorescence staining in the HKT-1097 cell line established from SHKT, thus illustrating the stability of galectin expression in tumor cells. Our data document the presence and differential regulation of galectins in the course of renal tumorigenesis in the model of DES-induced SHKT., Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

The current study focused on galectins (-1, -3, -4, -7, and -8) and deliberately performed immunohistochemical fingerprinting to explore their complexity in a context of experimental renal carcinogenesis. The diethylstilbestrol (DES)-induced renal tumors in male Syrian hamster kidney (SHKT) represent a unique animal model for the study of estrogen-dependent renal malignancies. Kidney sections of DES-treated hamsters (3 days to 11 months of DES exposure) were analyzed by immunohistochemistry using a panel of non-crossreactive antibodies raised against galectins-1, -3, -4, -7, and -8. Levels of expression were quantitatively determined by using computer-assisted microscopy on immunostained tissue sections. Except for galectin-4, all above mentioned galectins were expressed in kidney tumors. Small clusters of galectin-1-positive, most likely preneoplastic cells at the corticomedullary junction were already evident 1 week after DES administration. Galectin-1 and -3 expression was apparently associated with the first steps of the neoplastic transformation, because small tumorous buds were found to be positive after 1 month of treatment. In contrast, galectins-7 and -8 were detected in large tumors and medium-sized tumors, respectively, thereby indicating an involvement in later stages of DES-induced SHKT. Galectins-1, -3, -7, and -8 were also detected by immunofluorescence staining in the HKT-1097 cell line established from SHKT, thus illustrating the stability of galectin expression in tumor cells. Our data document the presence and differential regulation of galectins in the course of renal tumorigenesis in the model of DES-induced SHKT., Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

For nearly forty years diethylstilbestrol (DES) was administered to pregnant women to maintain healthy pregnancies. During this time, it is estimated that several million men and women have been exposed to DES during sometime of their life. The most common period of exposure was during fetal development. Although rarely used for the maintenance of pregnancy now, its current medical use is restricted to certain clinical situations such as breast and prostate cancer therapies in adults. Thus, DES exposure spans the entire lifetime, from prenatal to geriatric age. Since the early 1950s, health risks were beginning to be associated with prenatal DES treatment. So far only reproductive problems such as infertility, neoplastic diseases of the cervix and vagina and testicular cancers have been well-documented in DES cases. Immunological abnormalities associated with DES are only now beginning to be recognized. Self-reported cases and questionnaire-based studies have revealed increased incidence of infections and autoimmune diseases in DES exposed people. Animal studies that have examined the immunological effects of DES treatment are largely restricted to one gender, or to one dose of DES or to the developmental period. This is an important issue since human exposure to DES occurred in both men and women, at all ages and, at a wide-range of doses. The purpose of these studies was to investigate the immunological consequences resulting from the exposure to DES. Since sensitivity can vary between genders, dose and at the time of exposure, it is critical to investigate the DES-induced immunological changes during all stages of life in both genders. To address these critical gaps in the literature, we examined the immunomodulatory effects of adult and prenatal exposure to DES in males and females. Our findings show that DES effects were evident in both the thymus and spleen. DES markedly affected the apoptosis of thymocytes and the ability of splenic lymphocytes to proliferate

RIVM rapport:In deze studie hebben we het mogelijke nut onderzocht van het inbouwen van immuunparameters in de "developmental toxicity study", zoals beschreven in het OECD 414 protocol. Diethylstibestrol (DES) werd daarbij als modelstof gebruikt, vanwege de toxische eigenschappen van deze stof voor zowel de embryogenese als voor het immuunsysteeem. De resultaten lieten embryotoxiciteit zien in de vorm van embryonale sterfte en verlaagd foetaal gewicht, terwijl voedselconsumptie en groei van de moederdieren achterbleven. Daarnaast werden bij pups histopathologische effecten gezien in uterus en ovarium, die verklaard kunnen worden uit de oestrogene werking van de modelstof. Echter, immunologische parameters, waaronder histopathologie, hematologie, en SRBC-respons in pups op de leeftijd van vier weken, vertoonden geen afwijkingen. We speculeren dat voor sommige verbindingen in tegenstelling tot de prenatale periode, waarin in deze studie werd blootgesteld, de vroege postnatale periode meer gevoelig zou kunnen zijn voor immunologische schade na blootstelling aan xenobiotica., In the present study, we have explored the usefulness of the inclusion of immune parameters within the prenatal developmental toxicity study in rats, as described in the OECD 414 guideline. Diethylstilbestrol was used as the model compound, as it is known to be toxic both for development and for the immune system. The results show developmental toxicity in terms of decreased fetal survival and body weight in the presence of reduced maternal food consumption and body weight. Histopathologic effects in ovaries and uteri of pups were reminiscent of the estrogenicity of the test compound. In contrast, immune parameters were uncompromised. Rather than the prenatal exposure protocol used here, the early postnatal period may be more vulnerable to immunotoxic injury after xenobiotic exposure.

In deze studie hebben we het mogelijke nut onderzocht van het inbouwen van immuunparameters in de "developmental toxicity study", zoals beschreven in het OECD 414 protocol. Diethylstibestrol (DES) werd daarbij als modelstof gebruikt, vanwege de toxische eigenschappen van deze stof voor zowel de embryogenese als voor het immuunsysteeem. De resultaten lieten embryotoxiciteit zien in de vorm van embryonale sterfte en verlaagd foetaal gewicht, terwijl voedselconsumptie en groei van de moederdieren achterbleven. Daarnaast werden bij pups histopathologische effecten gezien in uterus en ovarium, die verklaard kunnen worden uit de oestrogene werking van de modelstof. Echter, immunologische parameters, waaronder histopathologie, hematologie, en SRBC-respons in pups op de leeftijd van vier weken, vertoonden geen afwijkingen. We speculeren dat voor sommige verbindingen in tegenstelling tot de prenatale periode, waarin in deze studie werd blootgesteld, de vroege postnatale periode meer gevoelig zou kunnen zijn voor immunologische schade na blootstelling aan xenobiotica., In the present study, we have explored the usefulness of the inclusion of immune parameters within the prenatal developmental toxicity study in rats, as described in the OECD 414 guideline. Diethylstilbestrol was used as the model compound, as it is known to be toxic both for development and for the immune system. The results show developmental toxicity in terms of decreased fetal survival and body weight in the presence of reduced maternal food consumption and body weight. Histopathologic effects in ovaries and uteri of pups were reminiscent of the estrogenicity of the test compound. In contrast, immune parameters were uncompromised. Rather than the prenatal exposure protocol used here, the early postnatal period may be more vulnerable to immunotoxic injury after xenobiotic exposure.

RIVM rapport:In deze studie hebben we het mogelijke nut onderzocht van het inbouwen van immuunparameters in de "developmental toxicity study", zoals beschreven in het OECD 414 protocol. Diethylstibestrol (DES) werd daarbij als modelstof gebruikt, vanwege de toxische eigenschappen van deze stof voor zowel de embryogenese als voor het immuunsysteeem. De resultaten lieten embryotoxiciteit zien in de vorm van embryonale sterfte en verlaagd foetaal gewicht, terwijl voedselconsumptie en groei van de moederdieren achterbleven. Daarnaast werden bij pups histopathologische effecten gezien in uterus en ovarium, die verklaard kunnen worden uit de oestrogene werking van de modelstof. Echter, immunologische parameters, waaronder histopathologie, hematologie, en SRBC-respons in pups op de leeftijd van vier weken, vertoonden geen afwijkingen. We speculeren dat voor sommige verbindingen in tegenstelling tot de prenatale periode, waarin in deze studie werd blootgesteld, de vroege postnatale periode meer gevoelig zou kunnen zijn voor immunologische schade na blootstelling aan xenobiotica., In the present study, we have explored the usefulness of the inclusion of immune parameters within the prenatal developmental toxicity study in rats, as described in the OECD 414 guideline. Diethylstilbestrol was used as the model compound, as it is known to be toxic both for development and for the immune system. The results show developmental toxicity in terms of decreased fetal survival and body weight in the presence of reduced maternal food consumption and body weight. Histopathologic effects in ovaries and uteri of pups were reminiscent of the estrogenicity of the test compound. In contrast, immune parameters were uncompromised. Rather than the prenatal exposure protocol used here, the early postnatal period may be more vulnerable to immunotoxic injury after xenobiotic exposure.

Antioestrogens are among the most widely used agents in the treatment of breast cancer. There has been a recent surge of interest in these compounds because of their potential breast cancer chemopreventive properties. The newer generation of antioestrogens, with increased selectivity and better toxicity profiles, have the potential to increase the effectiveness of hormonal treatment of breast cancer. The selective oestrogen receptor modulators (SERMs) hold the promise of revolutionising the care of healthy postmenopausal women with their beneficial effects on bone and lipids in addition to the chemoprevention of breast cancer.

RIVM rapport:In deze studie hebben we het mogelijke nut onderzocht van het inbouwen van immuunparameters in de "developmental toxicity study", zoals beschreven in het OECD 414 protocol. Diethylstibestrol (DES) werd daarbij als modelstof gebruikt, vanwege de toxische eigenschappen van deze stof voor zowel de embryogenese als voor het immuunsysteeem. De resultaten lieten embryotoxiciteit zien in de vorm van embryonale sterfte en verlaagd foetaal gewicht, terwijl voedselconsumptie en groei van de moederdieren achterbleven. Daarnaast werden bij pups histopathologische effecten gezien in uterus en ovarium, die verklaard kunnen worden uit de oestrogene werking van de modelstof. Echter, immunologische parameters, waaronder histopathologie, hematologie, en SRBC-respons in pups op de leeftijd van vier weken, vertoonden geen afwijkingen. We speculeren dat voor sommige verbindingen in tegenstelling tot de prenatale periode, waarin in deze studie werd blootgesteld, de vroege postnatale periode meer gevoelig zou kunnen zijn voor immunologische schade na blootstelling aan xenobiotica., In the present study, we have explored the usefulness of the inclusion of immune parameters within the prenatal developmental toxicity study in rats, as described in the OECD 414 guideline. Diethylstilbestrol was used as the model compound, as it is known to be toxic both for development and for the immune system. The results show developmental toxicity in terms of decreased fetal survival and body weight in the presence of reduced maternal food consumption and body weight. Histopathologic effects in ovaries and uteri of pups were reminiscent of the estrogenicity of the test compound. In contrast, immune parameters were uncompromised. Rather than the prenatal exposure protocol used here, the early postnatal period may be more vulnerable to immunotoxic injury after xenobiotic exposure.

With the growing concern that environmental chemicals might impair human and animal fertility, it is important to investigate the possible influence of these substances on sexual differentiation and genital development of mammals. Many of these substances are suspected to interfere with endocrine processes, and exposure during critical periods of prenatal development might affect reproductive performance over several generations. Alkylphenols and their metabolites are lipophilic substances exerting apparent estrogenic action in in vitro and in vivo testing systems. With the widespread industrial use of alkylphenols, these are disseminated in the environment with sewage sludge, and domestic animals and humans are likely to be exposed via the food chain. Using the pig as an in vivo model, we studied the effect of intrauterine exposure to tertiary octylphenol (OP) on essential reproductive parameters over 3 generations. Sows were treated daily from D 23 to 85 of pregnancy with either 0, 10 or 1000 micrograms OP/kg body weight. Treatment with OP extended pregnancy length and induced basal cell proliferation in the cervical epithelium of the parental generation. In F1 offspring of sows treated with the low dosage of OP, onset of puberty was accelerated. Furthermore, when F1 gilts and F1 boars originating from sows treated with high dosages of OP were bred, the litter size was reduced. The results of the present study are compared with previous reports on estrogenicity of OP, and the usefulness of in vivo animal or embryo models for the evaluation of possible consequences of human exposure to endocrine disrupting compounds is discussed. Furthermore, possible consequences of exposure to endocrine disrupting compounds for the embryo transfer industry are addressed.

With the growing concern that environmental chemicals might impair human and animal fertility, it is important to investigate the possible influence of these substances on sexual differentiation and genital development of mammals. Many of these substances are suspected to interfere with endocrine processes, and exposure during critical periods of prenatal development might affect reproductive performance over several generations. Alkylphenols and their metabolites are lipophilic substances exerting apparent estrogenic action in in vitro and in vivo testing systems. With the widespread industrial use of alkylphenols, these are disseminated in the environment with sewage sludge, and domestic animals and humans are likely to be exposed via the food chain. Using the pig as an in vivo model, we studied the effect of intrauterine exposure to tertiary octylphenol (OP) on essential reproductive parameters over 3 generations. Sows were treated daily from D 23 to 85 of pregnancy with either 0, 10 or 1000 micrograms OP/kg body weight. Treatment with OP extended pregnancy length and induced basal cell proliferation in the cervical epithelium of the parental generation. In F1 offspring of sows treated with the low dosage of OP, onset of puberty was accelerated. Furthermore, when F1 gilts and F1 boars originating from sows treated with high dosages of OP were bred, the litter size was reduced. The results of the present study are compared with previous reports on estrogenicity of OP, and the usefulness of in vivo animal or embryo models for the evaluation of possible consequences of human exposure to endocrine disrupting compounds is discussed. Furthermore, possible consequences of exposure to endocrine disrupting compounds for the embryo transfer industry are addressed.

A subgroup from a National Institute of Environmental Health Sciences, workshop concerned with characterizing the effects of endocrine disruptors on human health at environmental exposure levels considered the question, If diethylstilbestrol (DES) were introduced into the market for human use today and likely to result in low-dose exposure of the human fetus, what would be required to assess risk? On the basis of an analysis of the quality of data on human DES exposure, the critical times and doses for inducing genital tract malformations and cancer must be determined. This would be facilitated through analysis of the ontogeny of estrogen receptor expression in the developing human genital tract. Models of low-dose estrogenic effects will have to be developed for human and rodent genital tract development. Mouse models offer many advantages over other potential animal models because of the wealth of the earlier literature, the availability of sensitive end points, the availability of mutant lines, and the possibility of generating genetically engineered model systems. Through multidisciplinary approaches, it should be possible to elucidate the cellular and molecular mechanisms of endocrine disruption elicited by estrogens during development and facilitate an assessment of risk to humans.

A subgroup from a National Institute of Environmental Health Sciences, workshop concerned with characterizing the effects of endocrine disruptors on human health at environmental exposure levels considered the question, If diethylstilbestrol (DES) were introduced into the market for human use today and likely to result in low-dose exposure of the human fetus, what would be required to assess risk? On the basis of an analysis of the quality of data on human DES exposure, the critical times and doses for inducing genital tract malformations and cancer must be determined. This would be facilitated through analysis of the ontogeny of estrogen receptor expression in the developing human genital tract. Models of low-dose estrogenic effects will have to be developed for human and rodent genital tract development. Mouse models offer many advantages over other potential animal models because of the wealth of the earlier literature, the availability of sensitive end points, the availability of mutant lines, and the possibility of generating genetically engineered model systems. Through multidisciplinary approaches, it should be possible to elucidate the cellular and molecular mechanisms of endocrine disruption elicited by estrogens during development and facilitate an assessment of risk to humans.

In dit 1e van 2 artikelen wordt informatie gegeven over de oestrus, de ovulatie en de conceptie

Antwoord op de 5 volgende vragen: Is er verschil in voorkomen van mammatumoren, endometritis, schijndracht en diabetes mellitus bij het gebruik van MPA of proligeston? Zijn eventuele verschillen in bijwerkingen afhankelijk van het feit of de progestagenen in de pro- of anoestrus worden toegediend? Hangen de bijwerkingen van de dosering of van de stof zelf af? Is er sprake van een drug of 'choice'? Als de teef al wat ouder is en de eigenaar wenst alsnog loopsheid-preventie, wat geniet dan de voorkeur: progestageen toediening of ovariectomie?

Op het ID-DLO te Zeist is men bezig met de ontwikkeling van een drachtigheidstester via het aantonen van bepaalde oestrogenen in de mest van de zeug

Beantwoording van de vraag bij de volgende situatieschets: een dierenarts wordt geroepen voor een verlossing bij een koe met een slecht ontsloten cervix. Wachten lijkt geen zin te hebben, want de vaars is lang genoeg bezig. Bestaan er medicijnen die de arts kan injecteren, waardoor de cervix verslapt. Geldt dit ook voor het schaap?

Several observations suggest that male reproductive health has been declining since World War II in many countries. The incidence of testicular cancer, hypospadias, and cryptorchidism has been increasing and semen quality has been decreasing, and these may have a common etiology. Treatment of several million pregnant women with the synthetic estrogen diethylstilbestrol led to an increase in these conditions among the sons of these women. These abnormalities probably arise during fetal development. The similarity between these effects and the adverse change in male reproductive development and function raised the question of whether the adverse changes are attributable to altered exposures to estrogenic and other endocrine-disrupting agents during fetal development. We speculate that alteration in exposure to estrogen in the past half-century may have caused the changes in male reproductive health.

Several observations suggest that male reproductive health has been declining since World War II in many countries. The incidence of testicular cancer, hypospadias, and cryptorchidism has been increasing and semen quality has been decreasing, and these may have a common etiology. Treatment of several million pregnant women with the synthetic estrogen diethylstilbestrol led to an increase in these conditions among the sons of these women. These abnormalities probably arise during fetal development. The similarity between these effects and the adverse change in male reproductive development and function raised the question of whether the adverse changes are attributable to altered exposures to estrogenic and other endocrine-disrupting agents during fetal development. We speculate that alteration in exposure to estrogen in the past half-century may have caused the changes in male reproductive health.

Ingegaan wordt op de rol van prostaglandinen inzake de vruchtbaarheid van melkkoeien