BACKGROUND: Traditional toxicological studies focus on individual compounds. However, this single-compound approach neglects the fact that the mixture exposed to human may act additively or synergistically to induce greater toxicity than the single compounds exposure due to their similarities in the mode of action and targets. Mixture effects can occur even when all mixture components are present at levels that individually do not produce observable effects. So the individual chemical effect thresholds do not necessarily protect against combination effects, an understanding of the rules governing the interactive effects in mixtures is needed. The aim of the study was to test and analyze the individual and combined estrogenic effects of a mixture of three endocrine disrupting chemicals (EDCs), bisphenol A (BPA), nonylphenol (NP) and diethylstilbestrol (DES) in immature rats with mathematical models. METHOD: In the present study, the data of individual estrogenic effects of BPA, NP and DES were obtained in uterotrophic bioassay respectively, the reference points for BPA, NP and DES were derived from the dose-response ralationship by using the traditional no observed adverse effect (NOAEL) or lowest observed adverse effect level (LOAEL) methods, and the benchmark dose (BMD) method. Then LOAEL values and the benchmark dose lower confidence limit (BMDL) of single EDCs as the dose design basis for the study of the combined action pattern. Mixed prediction models, the 3 × 2 factorial design model and the concentration addition (CA) model, were employed to analyze the combined estrogenic effect of the three EDCs. RESULTS: From the dose-response relationship of estrogenic effects of BPA, NP and DES in the model of the prepuberty rats, the BMDL(NOAEL) of the estrogenic effects of BPA, NP and DES were 90(120) mg/kg body weight, 6 mg/kg body weight and 0.10(0.25) μg/kg body weight, and the LOAEL of the the estrogenic effects of three EDCs were 240 mg/kg body weight, 15 mg/kg body weight and 0.50 μg/kg body weight, respectively. At BMDL doses based on the CA concept and the factorial analysis, the mode of combined effects of the three EDCs were dose addition. Mixtures in LOAEL doses, NP and DES combined effects on rat uterine/body weight ratio indicates antagonistic based on the CA concept but additive based on the factorial analysis. Combined effects of other mixtures are all additive by using the two models. CONCLUSION Our results showed that CA model provide more accurate results than the factorial analysis, the mode of combined effects of the three EDCs were dose addition, except mixtures in LOAEL doses, NP and DES combined effects indicates antagonistic effects based on the CA model but additive based on the factorial analysis. In particular, BPA and NP produced combination effects that are larger than the effect of each mixture component applied separately at BMDL doses, which show that additivity is important in the assessment of chemicals with estrogenic effects. The use of BMDL as point of departure in risk assessment may lead to underestimation of risk, and a more balanced approach should be considered in risk assessment.
Animals ; Benzhydryl Compounds ; toxicity ; Diethylstilbestrol ; toxicity ; Dose-Response Relationship, Drug ; Drug Interactions ; Endocrine Disruptors ; toxicity ; Estrogens ; toxicity ; Models, Theoretical ; Phenols ; toxicity ; Rats ; Rats, Sprague-Dawley ; Risk Assessment

Objective: To investigate the influence of diethylstilbestrol (DES) on the mRNA expressions of the androgen receptor (AR), estrogen receptor α (ERα), proliferating cell nuclear antigen (PCNA), and actin alpha 1 (ACTα1) in the gubernaculums testis of newborn mice and explore their action mechanisms. METHODS: A total of 140 male Kunming mice were randomly divided into a blank control, a dimethyl sulfoxide (DMSO) control, and 5 experimental groups to be treated subcutaneously with normal saline, DMSO, and DES at 0.02, 0.1, 0.5, 10 and 50 μg per kg of the body weight per day, respectively, at gestation days 9－17. On the first day after birth, the animals were sacrificed and the gubernaculums testis collected for detection of the mRNA expressions of AR, ERα, PCNA and ACTα1 by RT-PCR. RESULTS: Compared with the DMSO control, the experimental groups, particularly the DES 10 and 50 μg groups, showed significant increases in the mRNA expression of ERα (RE2 = 0.825, P <0.05), but remarkable decreases in those of AR, PCNA and ACTα1 (RA2 = 0.713, RP2 = 0.946, RT2 = 0.960, P <0.01), all in a dose-dependent manner. CONCLUSIONS The AR, ERα, PCNA, and ACTα1 mRNA are expressed in the gubernaculum testis of normal newborn mice, and their expression levels may be influenced by intervention with different concentrations of DES during the gestation. Exogenous estrogens may affect the proliferation and contraction of gubernaculum testis cells and consequently the normal development of the testis or even the whole male reproductive system by influencing the metabolism of ER and/or AR.
Actins ; metabolism ; Animals ; Animals, Newborn ; Cells, Cultured ; Diethylstilbestrol ; pharmacology ; Dimethyl Sulfoxide ; pharmacology ; Estrogen Receptor alpha ; metabolism ; Estrogens, Non-Steroidal ; pharmacology ; Genitalia, Male ; Gubernaculum ; drug effects ; metabolism ; Male ; Mice ; Proliferating Cell Nuclear Antigen ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Receptors, Androgen ; metabolism ; Testis ; drug effects ; metabolism

Adenocarcinoma, Clear Cell ; diagnosis ; etiology ; therapy ; Cervix Uteri ; pathology ; Child ; Diethylstilbestrol ; Fatal Outcome ; Female ; Humans ; Magnetic Resonance Imaging ; Pregnancy ; Prenatal Exposure Delayed Effects ; Uterine Cervical Neoplasms ; diagnosis ; etiology ; therapy

OBJECTIVETo develop a quartz crystal microbalance (QCM) immunosensor with high sensitivity and selectivity for the rapid detection of diethylstilbestrol.

METHODSDextran was used as reducing agent for preparing gold nanoparticles (AuNPs) with the size of 40 nm. The AuNPs were coupled with anti-DES antibody after amination. A monolayer was generated after immersing the quartz crystal into the solution of 5 mmol/L 11-mercaptoundecanoic acid(MUA) for 16 hours. After the monolayer was activated by 1-ethyl-3-(3-dimethylaminopropry) carbodiimide hydrochloride (EDC·HCl) and N-hydrosuccinimide (NHS), 20 μl of 2.2 mg/ml DES-HS-BSA was dropped onto the surface of crystal to prepare a sensitive membrane which can recognize DES specifically. Then, 50 μl of 1 mol/L ethanolamine (pH 8.5) was used to seal the carboxylic groups to make the sensitive membrane which could identify DES specifically. QCM immunosensor was used as detection platform to optimize the reaction conditions. Under the optimized conditions, 10 μl of 28 μg/ml AuNPs-antibody was mixed with 10 μl of 0.03-2.5 μg/ml DES, and the mixture was added on the sensitive membrane. QCM immunosensor was used to detect the signals and the standard curve was obtained at the same time. The detection limit was calculated based on the standard curve. The specificity was evaluated by testing DES and its analogues with the same concentration.

RESULTSThe optimized concentration for the immobilization of DES-HS-BSA on the surface of QCM was 2.2 mg/ml. The optimized concentration for coupling anti-DES antibody with AuNPs was 7 μg/ml and 15 nmol/L, respectively. The optimized concentration of AuNPs-antibody was 14 μg/ml. The logarithm of DES concentration was proportional to the frequency shift in the range of 0.16-500 ng/ml, Δf=-24.170 lgCDES+69.71, R(2)=0.998. The detection limit of this method was 0.13 ng/ml. DES analogues could not influence the detection of DES obviously, so the sensor had good specificity.

CONCLUSIONThe quartz crystal microbalance immunosensor with gold nanoparticals amplification could detect DES sensitively and rapidly.

Biosensing Techniques ; Diethylstilbestrol ; isolation & purification ; Gold ; Limit of Detection ; Nanoparticles ; Quartz Crystal Microbalance Techniques

Endometrial cancer is the most common gynecologic malignancy in developed countries. Clear cell carcinoma typically occurs in the ovaries, and very rarely occurs in the endometrium; it accounts for less than 3% of all endometrial cancers. It is presumed that clear cell carcinomas are of Müllerian duct origin, and an association with exposure to diethylstilbestrol (DES) or other nonsteroidal follicle stimulating hormones has been described. We report a case of a postmenopausal woman who presented with vaginal bleeding without a specific medical history. Under the impression of an endometrial mass, we performed a laparoscopic operation. Pathologic results showed clear cell carcinoma of the endometrium. Depth of invasion was 0.2 cm out of a 0.5 cm total thickness, and the rectal shelf mass was clear cell carcinoma. We report the case with a brief review of the relevant literature.
Adenocarcinoma ; Developed Countries ; Diethylstilbestrol ; Endometrial Neoplasms ; Endometrium ; Female ; Humans ; Ovary ; Postmenopause ; Uterine Hemorrhage

OBJECTIVETo study the expression of nNOS and ultrastructural changes in the penile tissue of rats with prolactinoma-induced erectile dysfunction (ED).

METHODSWe established the model of prolactinoma in 20 male Westar rats by peritoneal injection of diethylstilbestrol (DES) and treated the control rats with normal saline (n = 10) or sterilized arachis oil (n = 10). After 8 weeks, we performed the apomorphine test and measured the weight of the pituitary gland and the levels of serum prolactin (PRL) and testosterone (T) to confirm the successful construction of the prolactinoma-induced ED model. Then we determined the expression of nNOS in the penile tissue by immunohistochemistry and examined the ultrastructural changes of the penile cavernosum under the transmission electron microscope.

RESULTSThe prolactinoma-induced ED model was successfully established in 15 rats. The weight of the pituitary gland was significantly increased in the rats treated with DES as compared with the normal saline and sterilized arachis oil controls ([46.7 ± 15.5] vs [11.7 ± 2.4] and [12.4 ± 2.3] mg, both P < 0.05). The level of serum PRL was markedly higher while that of T remarkably lower in the former than in the latter two groups ([1,744.9 ± 304.5] vs [11.5 ± 2.4] and [10.6 ± 1.9] ng/ml, both P < 0.0l; [1.54 ± 0.46] vs [3.11 ± 1.08] and [3.04 ± 1.11] ng/ml, both P < 0.05). The rate of penile erection was significantly reduced in the prolactinoma-induced ED model rats in comparison with the normal saline and arachis oil controls (16.7% vs 100% and 87.5%, both P < 0.05), and so was the expression of nNOS in the penile tissue (0.024 ± 0.011 vs 0.066 ± 0.019 and 0.058 ± 0.021, both P < 0.05). Transmission electron microscopy manifested significant ultrastructural changes in the endothelial and smooth muscle cells of the cavernous tissue in the prolactinoma-induced ED models.

CONCLUSIONThe ultrastructural changes of the penile cavernous tissue and the reduced expression of nNOS in penile tissue may be the most important mechanisms of prolactinoma-induced ED in rats.

Animals ; Apomorphine ; Carcinogens ; Diethylstilbestrol ; Erectile Dysfunction ; etiology ; Humans ; Male ; Myocytes, Smooth Muscle ; ultrastructure ; Nitric Oxide Synthase Type I ; metabolism ; Organ Size ; Penile Erection ; Penis ; enzymology ; ultrastructure ; Pituitary Neoplasms ; chemically induced ; complications ; Prolactin ; blood ; Prolactinoma ; chemically induced ; complications ; Rats ; Rats, Wistar ; Testosterone ; blood

OBJECTIVETo synthesize artificial diethylstilbestrol (DES) antigen and to prepare DES polyclonal antibody with high titer and sensitivity.

METHODSThe derivative of DES (DES-HS) was synthesized from diethylstilbestrol, ethyl bromoacetate,bovine serum albumin (BSA) and chicken ovalbumin (OVA) with the nucleophilic substitution reaction; the compound was identified by electrospray ionization mass spectrometry(ESI-MS). The DES-HS and the carrier proteins (BSA, OVA) were cross-linked to prepare the artificial antigen; the UV absorption spectrophotometry and high performance liquid chromatography (HPLC) were used to identify the prepared artificial antigen. The rabbits were immunized with the DES artificial antigen to prepare the DES polyclonal antibodies.

RESULTSThe DES-HS was synthesized. The DES artificial antigen was prepared successfully with a coupling rate of 22:1. The DES polyclonal antibodies with a titer of 1:25 600 and IC50 of 10.81 ng/ml were prepared with DES artificial antigen.

CONCLUSIONA set of methods to synthesize DES artificial antigen and to prepare the DES polyclonal antibodies has been developed successfully.

Animals ; Antibodies ; immunology ; Antigens ; chemistry ; immunology ; Diethylstilbestrol ; analogs & derivatives ; immunology ; Enzyme-Linked Immunosorbent Assay ; methods ; Male ; Rabbits

OBJECTIVETo study whether effect of aspirin plus low-dose diethylstilbestrol is more effective and safer than high diethylstilbestrol dose alone on prevention of ovariectomy-induced osteopenia and dyslipidemia.

METHODSThirty-eight 4-month-old female SD rats were divided into baseline (BAS) group (n=6), sham operation group (n=8) and ovariectomy (OVX) group (n=24). The OVX group was further divided into vehicle treatment group (n=8), diethylstilbestrol (30 μg/kg•d) treatment group (OVX+D30 group, n=8), and aspirin (9 mg/kg•d) plus diethylstilbestrol (10 μg/kg•d) treatment group (OVX+A-D10 group, n=8). Their left tibiae were collected for the bone histomorphometric analysis in undecalcified sections. Left femurs were collected for the bone mineral density measurement.

RESULTSThe body weight and serum cholesterol were increased, while uterine weight and cancellous bone mass were decreased in OVX rats compared with the SHAM group. Cancellous bone mass was significantly increased, while body weight and bone resorption parameters were decreased in both A-D10 and D30 treatment group compared with OVX group. The rats treated with A-D10 showed significantly increased in bone formation parameters and decreased in serum triglyceride compared with the D30-treated rats.

CONCLUSIONAspirin plus low-dose diethylstilbestrol can effectively prevent osteopenia by reducing bone resorption, and is thus a better treatment modality for preventing dyslipidemia than high-dose diethylstilbestrol alone.

Animals ; Anti-Inflammatory Agents, Non-Steroidal ; pharmacology ; therapeutic use ; Aspirin ; pharmacology ; therapeutic use ; Biomarkers ; blood ; Body Weight ; drug effects ; Bone Density ; Bone Diseases, Metabolic ; blood ; prevention & control ; Bone and Bones ; drug effects ; Diethylstilbestrol ; pharmacology ; therapeutic use ; Drug Evaluation, Preclinical ; Drug Therapy, Combination ; Dyslipidemias ; blood ; prevention & control ; Estrogens, Non-Steroidal ; pharmacology ; therapeutic use ; Female ; Organ Size ; drug effects ; Ovariectomy ; Rats ; Uterus ; drug effects

OBJECTIVETo investigate the impact of prenatal exposure to diethylstilbestrol (DES) on the specific receptor LGR8 of insulin-like factor 3 (INSL3) in the mouse gubernaculum testis, and that of exoestrogens on descensus testis in mice.

METHODSA total of 120 pregnant KM mice aged 8 to 10 weeks were assigned to a normal, a blank control and 4 DES groups of equal number, the blank controls injected subcutaneously with dimethyl sulfoxide plus normal saline, and the DES groups with DES at 0.1, 1, 10 and 100 microg/kg body weight, respectively, from embryonic day 9 (ED9) through ED17. Immunohistochemistry and RT-PCR were used to detect the expressions of LGR8 protein and mRNA in the gubernaculum testis of the ED18 fetuses and PND20 (postnatal day 20) offspring of the mice.

RESULTSHistological analysis showed that the gubernaculum testis of the ED18 fetuses were well developed in both the normal and control groups, with an inner mesenchymal core and muscular outer layer. In contrast, the gubernaculum testis were poorly developed in the experimental groups, morphologically abnormal and without visible dividing line between the mesenchymal tissue and the muscular outer layer. No obvious differences were found in the gubernaculum testis development of the neonates between the normal and experimental groups. Positive immunostaining was seen in the mesenchymal core and muscular outer layer, but mainly in the latter. The expression of LGR8 was weaker in the experimental groups than in the normal group (P < 0.05), but that of LGR8 mRNA was increased in the high-dose (10 and 100 microg/kg) DES groups (P < 0.05). No obvious mutations were observed in the PCR products in any of the experimental groups.

CONCLUSIONPrenatal exposure to diethylstilbestrol affected the expression of LGR8 mRNA in the mouse gubernaculum testis, which suggests that diethylstilbestrol may induce cryptorchidism by interfering with the INSL3-LGR8 signaling system and consequently the development of the gubernaculum testis.

Animals ; Diethylstilbestrol ; pharmacology ; Female ; Male ; Mice ; Mice, Inbred Strains ; Pregnancy ; Receptors, G-Protein-Coupled ; metabolism ; Testis ; drug effects ; embryology ; metabolism

OBJECTIVETo establish quality control criteria for medicinal herb Cajanus cajan based on the determination of longistylin A and longistylin C, two bioactive and specific stilbenes of the plant.

METHODLongistylin A and longistylin C were obtained from the leaves of C. cajan by silica gel column chromatography and identified as marker compounds of this plant by spectroscopic analysis. A RP-HPLC method was established to determine the two compounds.

RESULTLongistylin A and longistylin C were well separated on a Thermo BDS Hypersil C18 column (4.6 mm x 250 mm, 5 microm) with a mobile phase methanol-water (8:2), and showed good linearity in the range of 0.00288 - 0.0576 microg and 0.0112 - 0.224 microg, respectively. The average recoveries were 98.9% and 97.2% with RSD of 2.4% and 2.2% for these two compounds, respectively.

CONCLUSIONThe established analysis method is simple and accurate, whicn can be used for quality control of C. cajan.

Cajanus ; chemistry ; Chromatography, High Pressure Liquid ; methods ; Diethylstilbestrol ; analysis ; isolation & purification ; Drugs, Chinese Herbal ; analysis ; isolation & purification ; Plant Leaves ; chemistry ; Plants, Medicinal ; chemistry