Estrone Sulfate Research Articles

Decreased Renal Organic Anion Transporter 3 Expression in Type 1 Diabetic Rats

BackgroundOrganic anion transporter 3 (Oat3) plays an essential role in the renal excretion of organic anions. Reduced renal Oat3 expression potentially contributes to an impaired anion clearance and causes abnormal kidney function. This study examined the effects of diabetes on the expression and function of rat renal Oat3. MethodsExperimental diabetes was induced by the administration of streptozotocin. Diabetic rats were randomly assigned to the treatment group or no treatment group with insulin for 4 weeks. The expression of renal Oat3, protein kinase Cα (PKCα), phospho-PKCα and nuclear factor kappa B (NF-κB) p65 were determined by immunoblotting. Estrone sulfate (Es) uptake into renal cortical slices was used as an indicator of renal Oat3 function. ResultsThe reduced expression of renal Oat3 was related to the decrease in [3H]Es uptake in a renal cortical slice of the diabetic rat. Insulin treatment restored the impairment of renal Oat3 function and expression. These may be because of the hyperglycemia-induced oxidative stress effectively activating the PKCα and NF-κB. Insulin treatment abolished these processes. ConclusionsThese data are the first to show that the decreased function and expression of renal Oat3 in diabetes was associated with an increase in reactive oxygen species production coinciding with the activation of PKC and NF-κB signaling pathway. These events may affect the transporter protein translocation and/or expression.

Hepatic Overexpression of Steroid Sulfatase Ameliorates Mouse Models of Obesity and Type 2 Diabetes through Sex-specific Mechanisms

The steroid sulfatase (STS)-mediated desulfation is a critical metabolic mechanism that regulates the chemical and functional homeostasis of endogenous and exogenous molecules. In this report, we first showed that the liver expression of Sts was induced in both the high fat diet (HFD) and ob/ob models of obesity and type 2 diabetes and during the fed to fasting transition. In defining the functional relevance of STS induction in metabolic disease, we showed that overexpression of STS in the liver of transgenic mice alleviated HFD and ob/ob models of obesity and type 2 diabetes, including reduced body weight, improved insulin sensitivity, and decreased hepatic steatosis and inflammation. Interestingly, STS exerted its metabolic benefit through sex-specific mechanisms. In female mice, STS may have increased hepatic estrogen activity by converting biologically inactive estrogen sulfates to active estrogens and consequently improved the metabolic functions, whereas ovariectomy abolished this protective effect. In contrast, the metabolic benefit of STS in males may have been accounted for by the male-specific decrease of inflammation in white adipose tissue and skeletal muscle as well as a pattern of skeletal muscle gene expression that favors energy expenditure. The metabolic benefit in male STS transgenic mice was retained after castration. Treatment with the STS substrate estrone sulfate also improved metabolic functions in both the HFD and ob/ob models. Our results have uncovered a novel function of STS in energy metabolism and type 2 diabetes. Liver-specific STS induction or estrogen/estrogen sulfate delivery may represent a novel approach to manage metabolic syndrome.

Relationship of body mass index with aromatisation and plasma and tissue oestrogen levels in postmenopausal breast cancer patients treated with aromatase inhibitors

BackgroundRecent data have raised concern about the clinical efficacy of aromatase inhibitors in overweight and/or obese breast cancer patients. We report in vivo aromatase inhibition and plasma and tissue oestrogen levels in relation to body mass index (BMI) status among breast cancer patients treated with different aromatase inhibitors. MethodsWe compared data on in vivo aromatase inhibition (64 patients) as well as plasma and tissue oestrogen levels from patients participating in our studies to BMI values. ResultsWe found a weak positive correlation between pretreatment aromatisation level and BMI (n=64; R=0.236; p=0.060) but no correlation between on-treatment aromatisation levels or percentage aromatase inhibition and BMI within patient subgroups treated with any of a panel of aromatase inhibitors. Pre-treatment levels of plasma estradiol (p<0.001), estrone (p=0.001) and estrone sulphate (p=0.002) correlated to BMI. While on-treatment levels of plasma estrane sulphate correlated to BMI in patients on letrozole (R=0.601; p=0.001; n=25 for all) or anastrozole (n=12; R=0.611; p=0.035) therapy, letrozole suppressed plasma estrone sulphate more than anastrozole independent of BMI. No correlation between on-treatment tumour oestrogen levels and BMI was recorded. ConclusionsOur unique data do not support a lack of effective aromatase inhibition in overweight patients or therefore a need for alternative therapy. The higher levels of estrogens in overweight postmenopausal breast cancer patients before and during aromatase inhibition may be due to effects of BMI on oestrogen metabolism rather than aromatisation.

Body mass index and circulating oestrone sulphate in women treated with adjuvant letrozole

Background:Obesity is an independent adverse prognostic factor in early breast cancer patients, but it is still controversial whether obesity may affect adjuvant endocrine therapy efficacy. The aim of our study (ancillary to the two clinical trials Gruppo Italiano Mammella (GIM)4 and GIM5) was to investigate whether the circulating oestrogen levels during treatment with the aromatase inhibitor letrozole are related to body mass index (BMI) in postmenopausal women with breast cancer.Methods:Plasma concentration of oestrone sulphate (ES) was evaluated by radioimmunoassay in 370 patients. Plasma samples were obtained after at least 6 weeks of letrozole therapy (steady-state time). Patients were divided into four groups according to BMI. Differences among the geometric means (by ANOVA and ANCOVA) and correlation (by Spearman's rho) between the ES levels and BMI were assessed.Results:Picomolar geometric mean values (95% confidence interval, n=patients) of circulating ES during letrozole were 58.6 (51.0–67.2, n=150) when BMI was <25.0 kg m−2; 65.6 (57.8–74.6, n=154) when 25.0–29.9 kg m−2; 59.3 (47.1–74.6, n=50) when 30.0–34.9 kg m−2; and 43.3 (23.0–81.7, n=16) when ⩾35.0 kg m−2. No statistically significant difference in terms of ES levels among groups and no correlation with BMI were observed.Conclusions:Body mass index does not seem to affect circulating oestrogen levels in letrozole-treated patients.

Estrone Sulfate Source of Estrone and Estradiol Formation in Isolated Human Hair Roots: Identification of a Pathway Linked to Hair Growth Phase and Subject to Site-, Gender-, and Age-Related Modulations

The present study investigated the metabolism of estrone sulfate into bioactive estrogens in the human hair root, including the effects of hair growth phase, anatomical site, gender, and age. Healthy male (n = 18) and female (n = 20) subjects were investigated. Growing (anagen) and resting (telogen) hair roots were collected from selected scalp and body sites. Estrone sulfate metabolism in the hair root yielded substantial levels of estrone and estradiol. Estrogen synthesis exceeded that associated with aromatization of androgens in a previous study. In subjects <50 years old, estrogen synthesis in scalp hair was lower in men than in women. Comparable levels of estrogen formation were observed in 1) male and female axillary and pubic hair and 2) male beard hair. These levels were higher than the estrogen levels detected in the in scalp hair of men <50 years old. With increasing age, estrogen synthesis increased in men and decreased in women. In telogen hair from all body sites, the capacity to form estrone from estrone sulfate remained unaffected, whereas the ability to form estradiol decreased by 62% and 86% in men and women, respectively. Estrogen formation from estrone sulfate in sexually dimorphic hair is linked to the hair growth phase and is subject to gender- and age-related modulations. The magnitude of the in situ estrogen synthesis from estrone sulfate and the selective arrest of estradiol synthesis at the end of the hair cycle suggest that this pathway plays a crucial role in the regulation of human hair growth.

Quercetin‐3‐rhamnoglucoside (rutin) stimulates transport of organic anion compounds mediated by organic anion transporting polypeptide 2B1

Quercetin-3-rhamnoglucoside (rutin) has a wide spectrum of biochemical and pharmacological activities. Rutin is absorbed mainly in its unmetabolized form. Organic anion transporting polypeptide (OATP) 2B1 is a major uptake transporter in the intestine. Thus, it is important for the prevention of adverse events to understand drug interactions mediated by OATP2B1 in the absorption process. This study assessed the effect of rutin on transport by OATP2B1. Rutin stimulated the uptake of estrone-3-sulfate (E-3-S), taurocholic acid (TCA), cholic acid (CA) and rosuvastatin by OATP2B1, but not p-coumaric acid or ferulic acid. The EC50 of rutin for transport by OATP2B1 was 2.32 μm. The Km value of E-3-S for OATP2B1 in the presence of rutin (9.21 μm) was almost the same as that in the absence of rutin (8.53 μm). On the other hand, the Vmax of E-3-S transport by OATP2B1 in the presence of rutin (270 pmol/mg protein/min) was 1.2-fold higher than that in the absence of rutin (218 pmol/mg protein/min). Moreover, the expression level of OATP2B1 on the cell membrane was increased by treatment with rutin for 5 min without alteration of the total OATP2B1 expression level. Moreover, the increase in the localization of OATP2B1 at the cell surface was detected by the immunocytochemistry. The stimulatory effect of rutin is a little weak but may affect the absorption of OATP2B1 substrates, because rutin is taken daily in foods and its intestinal concentration would reach the stimulatory range of OATP2B1.

Relationship between the somatic cell count in milk and reproductive function in peripartum dairy cows.

The aim of the present study was to examine the effect of the somatic cell count (SCC) in milk on reproductive performance, such as pregnancy status in the prepartum period and ovarian function in the postpartum period, in dairy cows. Blood samples were collected every week from one month prepartum to parturition in order to measure the concentrations of 13,14-dihydro-15-keto-PGF2α (PGFM), estrone sulfate (E1S) and progesterone. Milk samples were collected three times per week in both the prepartum (for one month before the dry period) and postpartum periods (for 3 months immediately after parturition) to measure the SCC. Progesterone was also determined in the whole milk of postpartum cows to define the day of the first ovulation. In the prepartum period, the maximum SCC negatively correlated with the pregnancy period (r = –0.77), but not the calf birth weight. Positive and negative correlations were observed between the average SCC and PGFM or progesterone concentrations in plasma, respectively (r = 0.84 or –0.92, respectively), at 39 weeks of pregnancy. In the postpartum period, a correlation was observed between the day of the first ovulation and both the average and maximum SCC (r = –0.74 and –0.75, respectively), whereas days open was not related to the SCC. These results suggest that a high SCC in the prepartum period may advance parturition by increasing PGF2α and decreasing progesterone and that the first ovulation in the postpartum period was affected by a high SCC.

Metabonomic analysis of quercetin against the toxicity of chronic exposure to low-level dichlorvos in rats via ultra-performance liquid chromatography–mass spectrometry

This study aims to determine whether quercetin elicits a protective effect against the toxicity of chronic exposure to low-level DDVP using metabonomic technology. Rats were randomly assigned into the control, DDVP-treated, quercetin-treated, and quercetin plus DDVP-treated groups. DDVP and quercetin were given to rats daily via drinking water and gavage respectively for 90 days. Eighteen metabolites, including the biomarkers of DDVP exposure (dimethyl phosphate, DMP) and quercetin exposure (quercetin and isorhamnetina), were identified from the metabonomic profiles of rat urine using ultra-performance liquid chromatography–mass spectrometry. Compared with the control group, the DDVP-treated group showed statistically significantly increased intensities of indoxyl sulfate, estrone sulfate, cholic acid, deoxycholic acid, p-cresol, p-cresol sulfate, and orotic acid but decreased intensities of suberic acid, citric acid, sebacic acid, hippuric acid, taurine, phosphocreatine, 3-hydroxyanthranilic acid, and kynurenic acid. The tendency of the aforesaid metabolites to change was significantly ameliorated in the quercetin (50mg/kg·bw) plus DDVP (7.2mg/kg·bw)-treated group compared with the DDVP-treated group. However, the levels of these metabolites in the quercetin plus DDVP-treated groups were still significantly different from those of the control group. These results indicate that quercetin has a partial protective effect on DDVP-induced toxicity.

The development of benzo- and naphtho-fused quinoline-2,4-dicarboxylic acids as vesicular glutamate transporter (VGLUT) inhibitors reveals a possible role for neuroactive steroids

Substituted quinoline-2,4-dicarboxylates (QDCs) are conformationally-restricted mimics of glutamate that were previously reported to selectively block the glutamate vesicular transporters (VGLUTs). We find that expanding the QDC scaffold to benzoquinoline dicarboxylic acids (BQDC) and naphthoquinoline dicarboxylic acids (NQDCs) improves inhibitory activity with the NQDCs showing IC50∼70μM. Modeling overlay studies showed that the polycyclic QDCs resembled steroid structures and led to the identification and testing of estrone sulfate, pregnenolone sulfate and pregnanolone sulfate that blocked the uptake of l-Glu by 50%, 70% and 85% of control, respectively. Pregnanolone sulfate was further characterized by kinetic pharmacological determinations that demonstrated competitive inhibition and a Ki of ≈20μM.

Inhibition of estrogen synthesis during the last trimester of gestation: changes in endocrine patterns, fetal growth and uterine artery hemodynamics in mares

Equine gestation is characterized by very high circulating concentrations of estrogens in the dam. The physiological roles of estrogens during late gestation are largely unknown, although some studies suggest a relationship between low circulating estrogen concentrations and late term pregnancy loss in the mare. Letrozole is a potent aromatase inhibitor that prevents the conversion of androgens to estrogens in the equine placenta. The objective of this study was to evaluate the effect of letrozole on circulating concentrations of estrogens, androgens, and progestins, and on uterine hemodynamics during the last trimester of pregnancy in mares, as well as the effect on fetal development. Multiparous mares of mixed breeds were randomly assigned to control (n1⁄46) or treatment (n1⁄46) groups. Treated mares received 500 mg of letrozole orally every 4 days starting at 240 days of gestation until parturition. Weekly, serum samples were analyzed using enzyme immunoassays to determine estrone sulfate (ES), progestins (P), testosterone (T) and dehydroepiandrosterone sulfate (DHEA-S) concentrations. To monitor the status of pregnancy: 1) the mean diameter of the fetal eye was measured as an estimate of fetal growth, 2) uterine artery (UA) diameters and 3) Doppler resistance and pulsatility indices (RI and PI) were determined in both uterine arteries by transrectal Doppler ultrasound every second week. Fetal development was evaluated based on foal weight and

Possible role of the aromatase-independent steroid metabolism pathways in hormone responsive primary breast cancers

Aromatase inhibitors (AIs) exert antiproliferative effects by reducing local estrogen production from androgens in postmenopausal women with hormone-responsive breast cancer. Previous reports have shown that androgen metabolites generated by the aromatase-independent enzymes, 5α-androstane-3β, 17β-diol (3β-diol), androst-5-ene-3β, and 17β-diol (A-diol), also activate estrogen receptor (ER) α. Estradiol (E2) can also reportedly be generated from estrone sulfate (E1S) pooled in the plasma. Estrogenic steroid-producing aromatase-independent pathways have thus been proposed as a mechanism of AI resistance. However, it is unclear whether these pathways are functional in clinical breast cancer. To investigate this issue, we assessed the transcriptional activities of ER in 45 ER-positive human breast cancers using the adenovirus estrogen-response element-green fluorescent protein assay and mRNA expression levels of the ER target gene, progesterone receptor, as indicators of ex vivo and in vivo ER activity, respectively. We also determined mRNA expression levels of 5α-reductase type 1 (SRD5A1) and 3β-hydroxysteroid dehydrogenase type 1 (3β-HSD type 1; HSD3B1), which produce 3β-diol from androgens, and of steroid sulfatase (STS) and 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD type 1; HSD17B1), which produce E2 or A-diol from E1S or dehydroepiandrosterone sulfate. SRD5A1 and HSD3B1 expression levels were positively correlated with ex vivo and in vivo ER activities. STS and HSD17B1 expression levels were positively correlated with in vivo ER activity alone. Elevated expression levels of these steroid-metabolizing enzymes in association with high in vivo ER activity were particularly notable in postmenopausal patients. Analysis of the expression levels of steroid-metabolizing enzymes revealed positive correlations between SRD5A1 and HSD3B1, and STS and HSD17B1. These findings suggest that the SRD5A1-HSD3B1 as well as the STS-HSD17B pathways, could contributes to ER activation, especially postmenopause. These pathways might function as an alternative estrogenic steroid-producing, aromatase-independent pathways.

Abstract C21: Inclusion of endogenous hormone levels in risk prediction models of postmenopausal breast cancer

Abstract Endogenous hormones have been associated with postmenopausal breast cancer risk and may improve our ability to identify women at high risk of breast cancer. In addition, having high levels of multiple sex hormones or prolactin appears to further increase risk of postmenopausal breast cancer. This suggests that including multiple hormones may improve risk prediction models more than adding one or two hormones individually. Therefore, we evaluated whether the inclusion of multiple hormones (estradiol, estrone, estrone sulfate, testosterone, DHEAS, prolactin, SHBG) improved risk prediction models of postmenopausal invasive breast cancer among 473 cases and 770 controls not using postmenopausal hormones at blood draw. We utilized two previously published breast cancer risk prediction models, the Gail model and the Rosner model. We evaluated the improvement of the AUC for 5-year risk of invasive breast cancer, and secondarily of estrogen receptor (ER) positive disease, using the Gail and Rosner risk scores for each hormone individually. Then we used step-wise regression to identify the subset of hormones that were associated most significantly with risk and assessed improvement in AUC. We used 70% of the data as a training set (n=314 cases/533 control) and 30% as an independent validation set (n=123 cases/240 control). In preliminary analyses, each hormone was associated with risk of invasive breast cancer (OR, doubling in levels=0.82 [SHBG] to 1.45 [testosterone]) in the training set. For invasive cancer, individual hormones improved the AUC by 2.0-7.6 units when included with the Gail score and 0.2-3.9 units for the Rosner score. Estrone sulfate, testosterone, and prolactin were selected by step-wise regression and together increased the AUC by 8.6 points (p&amp;lt;0.001) for the Gail and 3.8 units (p=0.06) for the Rosner score. In the independent set, the corresponding change in the AUC was 5.0 (p=0.09) and 5.1 (p=0.11) units, respectively. Similar results were observed for ER+ disease specifically (223 cases). In the training dataset, the best hormone subset included estrone sulfate, testosterone, prolactin, and SHBG, leading to a change in AUC=7.3 (p=0.004) for the Gail and 5.5 (p=0.01) for the Rosner score. The change in AUC was higher in the independent datasets (12.5 [p=0.006] and 8.3 [p=0.06], respectively). Our results strongly support that endogenous hormones can improve risk prediction for invasive breast cancer and may help identify women who would benefit from chemoprevention. The improvement in the AUC observed when adding circulating hormone levels was similar or better than prior studies that considered adding genetic risk factors or mammographic density, and since hormone levels are not strongly correlated with these other risk factors, future studies should consider simultaneous inclusion of all these factors. Citation Format: Shelley S. Tworoger, Xuehong Zhang, A. Heather Eliassen, Jing Qian, Walter C. Willett, Graham A. Colditz, Bernard A. Rosner, Peter Kraft, Susan E. Hankinson. Inclusion of endogenous hormone levels in risk prediction models of postmenopausal breast cancer. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr C21.

Associations between Dietary Acrylamide Intake and Plasma Sex Hormone Levels

The rodent carcinogen acrylamide was discovered in 2002 in commonly consumed foods. Epidemiologic studies have observed positive associations between acrylamide intake and endometrial, ovarian, and breast cancer risks, which suggest that acrylamide may have sex-hormonal effects. We cross-sectionally investigated the relationship between acrylamide intake and plasma levels of sex hormones and sex hormone-binding globulin (SHBG) among 687 postmenopausal and 1,300 premenopausal controls from nested case-control studies within the Nurses' Health Studies. There were no associations between acrylamide and sex hormones or SHBG among premenopausal women overall or among never-smokers. Among normal-weight premenopausal women, acrylamide intake was statistically significantly positively associated with luteal total and free estradiol levels. Among postmenopausal women overall and among never-smokers, acrylamide was borderline statistically significantly associated with lower estrone sulfate levels but not with other estrogens, androgens, prolactin, or SHBG. Among normal-weight women, (borderline) statistically significant inverse associations were noted for estrone, free estradiol, estrone sulfate, DHEA, and prolactin, whereas statistically significant positive associations for testosterone and androstenedione were observed among overweight women. Overall, this study did not show conclusive associations between acrylamide intake and sex hormones that would lend unequivocal biologic plausibility to the observed increased risks of endometrial, ovarian, and breast cancer. The association between acrylamide and sex hormones may differ by menopausal and overweight status. We recommend other studies investigate the relationship between acrylamide and sex hormones in women, specifically using acrylamide biomarkers. The present study showed some interesting associations between acrylamide intake and sex hormones that urgently need confirmation.

Abstract A57: Alcohol consumption and plasma sex steroids in premenopausal women

Abstract Purpose: Alcohol consumption is a consistent risk factor for breast cancer, and evidence suggests premenopausal plasma hormones are associated with breast cancer. In this study, we examined the association between alcohol consumption and plasma sex steroid hormones in premenopausal women. Methods: We assessed the cross-sectional association between alcohol intake and circulating sex steroid concentrations among 2,034 premenopausal women in the Nurses' Health Study II (NHSII). Plasma concentrations of estradiol, estrone, estrone sulfate, testosterone, androstenedione, progesterone, prolactin, dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulphate (DHEAS) were measured in samples collected in 1996-99. Estrogens were measured in both the follicular and luteal phases of the menstrual cycle, while androgens were measured in the luteal phase as well as in random samples that were not timed in the menstrual cycle. Average alcohol intake was calculated from semi-quantitative food frequency questionnaires collected in 1995 and 1999. Results: Alcohol consumption was positively association with concentrations of luteal estrone (p-trend&amp;lt;0.0001) and luteal estradiol (p-trend=0.0001). Women who consumed more than 20 grams of alcohol per day, compared with non-drinkers, had higher concentrations of luteal estrone (geometric mean 98.0 vs. 79.9 pg/mL) and luteal estradiol (152.5 vs. 123.3 pg/mL). We did not observe statistically significant associations between alcohol and follicular estrogens, luteal estrone sulfate, testosterone, androstenedione, progesterone, prolactin, DHEA or DHEAS. Conclusion: Alcohol consumption was significantly positively associated with luteal estrogen concentrations, but not with plasma androgen levels, nor estrogens measured in the follicular phase. Thus, luteal estrogen levels may mediate the association between alcohol and breast cancer. Citation Format: Kelly A. Hirko, Susan E. Hankinson, A. Heather Eliassen. Alcohol consumption and plasma sex steroids in premenopausal women. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr A57.

Caffeic acid inhibits organic anion transporters OAT1 and OAT3 in rat kidney

Some food components influence drug elimination. Previously, we found that caffeic acid, present in coffee, fruits, and vegetables, strongly inhibited human homologs of organic anion transporters (OATs) OAT1 and OAT3, which are responsible for renal tubular secretion of anionic drugs. In this study, we examined the effect of caffeic acid on drug transport by OAT1 and OAT3 in the rat kidney. The inhibitory effect of caffeic acid on rat OAT1 and OAT3 was assessed by drug uptake experiment using Xenopus laevis oocytes. Urinary excretion of phenolsulfonphthalein (PSP), a diagnostic agent secreted by renal OATs, was examined in rats, and the influence of caffeic acid was evaluated. Expression of rat OAT1 (rOAT1) and rOAT3 stimulated uptake of their typical substrates, p-aminohippurate and estrone sulfate, respectively, into oocytes, and caffeic acid inhibited them dose dependently. After intravenous injection of PSP in rats, 42.7% of the dose was excreted into urine up to 60 min, and the simultaneous administration of caffeic acid reduced it to 32.0%. These findings show that caffeic acid inhibits OAT1 and OAT3 in the rat kidney.

QSAR analysis of the effects of OATP1B1 transporter by structurally diverse natural products using a particle swarm optimization-combined multiple linear regression approach

The inhibitory effect of 100 structurally diverse natural products on the uptake of estrone-3-sulfate (E3S) by OATP1B1 was evaluated using a rapid transport assay. For each natural product, a total of 252 two-dimensional descriptors were calculated using ChemoPy software package developed by our group. Using a particle swarm optimization-based multiple linear regression (PSO-MLR) method, the desired descriptors were automatically selected to maximize the predictability of the IC50 values. The logarithm of IC50 values of the natural products tested ranged from 2.009 to 2.882. Based on the PSO-MLR method, nine ChemoPy descriptors were found to be important and effective for QSAR modeling. Interestingly, these descriptors suggested that the molecular complexity and electrotopological state would be important factors in determining natural products-OATP1B1 interactions. In the leave-one-out prediction, the correlation coefficient of prediction (Q) and the standard error of prediction (s) were 0.824 and 0.098, respectively. Even in an external validation, the predictions were in good agreement with experimental values (Rpred=0.820, s=0.109, n=20). The proposed model, in which ChemoPy descriptors were used as molecular descriptors, was able to predict drug-OATP1B1 interactions with reasonable accuracy.

Clinical, ultrasonographic, and endocrinological studies on donkey pregnancy

Although donkey breeding has gained new interest in the past two decades, knowledge about donkey reproduction is still scarce, particularly on jenny pregnancy. The aim of this study was to describe the ultrasonographic and endocrine profiles of the physiological pregnancy in the jenny. The study was performed on 12 pregnancies of 7 Amiata donkeys from Day 10 after ovulation to delivery. Because three pregnancies, respectively at weeks 42, 44, and 45, were considered pathologic and treated pharmacologically, data collected from 2 weeks before diagnosis to the end of pregnancy were removed from the analysis. Average length of the normal pregnancies was 353.4 ± 13.0 days (range, 339–370 days). Timing, dimensions, and development during the first phases of embryonic growth, evaluated using transrectal ultrasound, were similar to that previously described in jennies and mares: first detection of embryonic vesicle was at 11.8 ± 1.3 days of gestation and diameter was 6.5 ± 1.9 mm, loss of spherical shape occurred at 18.5 ± 1.4 days, and embryo and heart beat were first seen at 22.0 ± 1.1 and 25 ± 1.1 days, respectively. The intrauterine growth in the second half of pregnancy, evaluated using the transrectal and transabdominal approach, also showed strong positive correlations, similar to that reported for the mare. The trends of the combined thickness of the utero-placental unit and the echogenicity of the amniotic and allantoic fluids are examples. The diameters (mm) of fetal chest, eye orbit, and aorta increased throughout pregnancy and were 40.6 ± 2.9, 8.7 ± 1.5, and 3.5 ± 0.7, respectively, at week 13, and 190.9 ± 12.0, 21.4 ± 1.5, and 30.6 ± 1.8 at the last evaluation before parturition. In contrast, heart rate decreased as pregnancy progressed. Regression analyses between these parameters and day of gestation were statistically significant (P < 0.001). All fetuses consistently showed some intrauterine activity. Maternal plasma progestagens and estrone sulfate concentrations followed a pattern similar to that seen in mares, although the prepartal progestagen peak was lower in jennies. This study provides a range of ultrasonographic and endocrine values for normal pregnancy in jennies.

Transplacental transfer and distribution of pravastatin

The objective of the study was to determine the bidirectional transfer of pravastatin across the dually perfused term human placental lobule and its distribution between the tissue and maternal and fetal circuits. The transfer of pravastatin was determined in the maternal-to-fetal (n= 11) and fetal-to-maternal (n= 10) directions. Pravastatin was coperfused with its [(3)H]-isotope and the marker compound antipyrine (20 μg/mL) and its [(14)C]-isotope. The concentration of pravastatin in the perfused tissue and the maternal and fetal circuits was determined using liquid scintillation spectrometry. Inside-out vesicles prepared from placental brush border membranes were utilized to investigate the role of efflux transporters in the transplacental transfer of pravastatin. Pravastatin was transferred from the maternal to the fetal circuit and vice versa. In the maternal-to-fetal direction, the distribution of pravastatin at the end of experiment was as follows: 14 ± 5% of the drug was retained by the tissue, 68 ± 5% remained in the maternal circuit, and 18 ± 4% was transferred to the fetal circuit. Thenormalized transfer of pravastatin (clearance index) to antipyrine in the fetal-to-maternal direction (0.48 ± 0.07) was higher than its transfer in the maternal-to-fetal direction (0.36 ± 0.07, P < .01). Furthermore, pravastatin inhibited the adenosine triphosphate (ATP)-dependent uptake of the paclitaxel and estrone sulfate. The transfer of pravastatin across the dually perfused placental lobule suggests that fetal exposure to pravastatin is plausible. The higher transfer of pravastatin in the fetal-to-maternal direction than the reverse as well as its inhibition of the ATP-dependent uptake of [(3)H]-paclitaxel and [(3)H]-estrone sulfate strongly suggest the involvement of efflux transporters in decreasing its transfer across the placenta and support pravastatin's favorable pharmacokinetic profile in pregnancy.

Sex Hormone Levels and Risk of Breast Cancer With Estrogen Plus Progestin

Although high endogenous sex hormone levels and estrogen plus progestin (E+P) therapy are associated with increased breast cancer risk, it is unknown whether pretreatment levels of sex hormones modify E+P effect on breast cancer. We conducted a nested case-control study within the Women's Health Initiative randomized clinical trial of E+P. The trial enrolled 16608 postmenopausal women aged 50 to 79 years with intact uterus and no breast cancer history. During a mean of 5.6 years of follow-up, 348 incident breast cancer case subjects were identified and matched with 348 control subjects. Case and control subjects had their sex hormone levels measured at baseline (estrogens, testosterone, progesterone, and sex hormone-binding globulin [SHBG]) and year 1 (estrogens and SHBG) using sensitive assays. All statistical tests were two-sided. Statistically significant elevations in breast cancer risk were seen with greater pretreatment levels of total estradiol (P trend = .04), bioavailable estradiol (P trend = .03), estrone (P trend = .007), and estrone sulfate (P trend = .007). E+P increased all measured estrogens and SHGB at year 1 (all P < .001). The effect of E+P on breast cancer risk was strongest in women whose pretreatment levels of total estradiol, bioavailable estradiol, and estrone were in the lowest quartiles. For example, the odds ratio for E+P relative to placebo was 2.47 (95% confidence interval [CI] = 1.28 to 4.79) in the lowest total estradiol quartile, compared with 0.96 (95% CI = 0.44 to 2.09) in the highest total estradiol quartile; P interaction = .04). Women with lower pr-treatment endogenous estrogen levels were at greater risk of breast cancer during E+P therapy compared with those with higher levels. Further studies are warranted to confirm these findings.

Identification of treatment by-products of the ozonation of estrone sulfate

This article presents a methodology developed in order to identify the potential by-products of emerging chemical pollutants generated during oxidation treatments like chlorination and ozonation. As an example, the study of ozonated real river water samples spiked with estrone sulfate (E1-S) was used to evaluate the impact of ozonation on E1-S concentration and to identify the generated treatment by-products (TBPs). After a large-scale solid phase extraction, samples were analyzed by liquid chromatography coupled with high resolution mass spectrometry (HRMS) and data were processed according to a differential metabolomic-like approach to uncover the produced compounds. Four main TBPs were found. ERα-CALUX bioassays were performed to measure the estrogenic potency of samples before and after treatment. Results show that the estrogenic potency decreases drastically in drinking water with ozonation.