Search

Gestational hyperandrogenism adversely impacts offspring health. Using an ovine model, we found that prenatal testosterone (T) excess adversely affects growth and cardiometabolic outcomes in female offspring and produces sex-specific effects on fetal myocardium. Since lipids are essential to cardiometabolic function, we hypothesized that prenatal T excess leads to sex-specific disruptions in lipid metabolism at birth. Shotgun lipidomics was performed on the plasma samples collected 48 hours after birth from female (F) and male (M) lambs of control (C) and (T) sheep (CF = 4, TF = 7, CM = 5, TM = 10) and data were analyzed by univariate analysis, multivariate dimensionality reduction modeling followed by functional enrichment, and pathway analyses. Biosynthesis of phosphatidylserine was the major pathway responsible for sex differences in controls. Unsupervised and supervised models showed separation between C and T in both sexes with glycerophospholipids and glycerolipids classes being responsible for the sex differences between C and T. T excess increased cholesterol in females while decreasing phosphatidylcholine levels in male lambs. Specifically, T excess: 1) suppressed the phosphatidylethanolamine N-methyltransferase (PEMT) phosphatidylcholine synthesis pathway overall and in TM lambs as opposed to suppression of carnitine levels overall and TF lambs; and 2) activated biosynthesis of ether-linked (O-)phosphatidylethanolamine and O-phosphatidylcholine from O-diacylglycerol overall and in TF lambs. Higher cholesterol levels could underlie adverse cardiometabolic outcomes in TF lambs, whereas suppressed PEMT pathway in TM lambs could lead to endoplasmic reticulum stress and defective lipid transport. These novel findings point to sex-specific effects of prenatal T excess on lipid metabolism in newborn lambs, a precocial ovine model of translational relevance. [ABSTRACT FROM AUTHOR]

Cardiovascular disease affects 1% to 4% of the nearly 4 million pregnancies in the United States each year and is the primary cause of pregnancy-related mortality. Adverse pregnancy outcomes are associated with cardiovascular complications during pregnancy persisting into the postpartum period. Recently, investigations have identified an altered sex hormone milieu, such as in the case of hyperandrogenism, as a causative factor in the development of gestational cardiovascular dysfunction. The mechanisms involved in the development of cardiovascular disease in postpartum women are largely unknown. Animal studies have attempted to recapitulate adverse pregnancy outcomes to investigate causal relationships and molecular underpinnings of adverse gestational cardiac events and progression to the development of cardiovascular disease postpartum. This review will focus on summarizing clinical and animal studies detailing the impact of adverse pregnancy outcomes, including preeclampsia, gestational diabetes mellitus, and maternal obesity, on gestational cardiometabolic dysfunction and postpartum cardiovascular disease. Specifically, we will highlight the adverse impact of gestational hyperandrogenism and its potential to serve as a biomarker for maternal gestational and postpartum cardiovascular dysfunctions. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Can mice serve as a translational model to examine the reproductive consequences of pubertal suppression with GnRH agonist (GnRHa) followed by testosterone (T) administration, a typical therapy in peripubertal transmasculine youth? SUMMARY ANSWER An implanted depot with 3.6 mg of GnRHa followed by T enanthate at 0.45 mg weekly can be used in peripubertal female mice for investigating the impact of gender-affirming hormone therapy in transmasculine youth. WHAT IS KNOWN ALREADY There is limited knowledge available in transgender medicine to provide evidence-based fertility care, with the current guidelines being based on the assumption of fertility loss. We recently successfully developed a mouse model to investigate the reproductive consequences of T therapy given to transgender men. On the other hand, to our knowledge, there is no mouse model to assess the reproductive outcomes in peripubertal transmasculine youth. STUDY DESIGN, SIZE, DURATION A total of 80 C57BL/6N female mice were used in this study, with n = 7 mice in each experimental group. PARTICIPANTS/MATERIALS, SETTING, METHODS We first assessed the effectiveness of GnRHa in arresting pubertal development in the female mice. In this experiment, 26-day-old female mice were subcutaneously implanted with a GnRHa (3.6 mg) depot. Controls underwent a sham surgery. Animals were euthanized at 3, 9, 21 and 28 days after the day of surgery. In the second experiment, we induced a transmasculine youth mouse model. C57BL/6N female mice were subcutaneously implanted with a 3.6 mg GnRHa depot on postnatal day 26 for 21 days and this was followed by weekly injections of 0.45 mg T enanthate for 6 weeks. The control for the GnRH treatment was sham surgery and the control for T treatment was sesame oil vehicle injections. Animals were sacrificed 0.5 weeks after the last injection. The data collected included the day of the vaginal opening and first estrus, daily vaginal cytology, weekly and terminal reproductive hormones levels, body/organ weights, ovarian follicular distribution and corpora lutea (CL) counts. MAIN RESULTS AND THE ROLE OF CHANCE GnRHa implanted animals remained in persistent diestrus and had reduced levels of FSH (P  = 0.0013), LH (P  = 0.0082) and estradiol (P  = 0.0155), decreased uterine (P  < 0.0001) and ovarian weights (P  = 0.0002), and a lack of CL at 21 days after GnRHa implantation. T-only and GnRHa+T-treated animals were acyclic throughout the treatment period, had sustained elevated levels of T, suppressed LH levels (P  < 0.0001), and an absence of CL compared to controls (P  < 0.0001). Paired ovarian weights were reduced in the T-only and GnRHa+T groups compared with the control and GnRHa-only groups. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION Although it is an appropriate tool to provide relevant findings, precaution is needed to extrapolate mouse model results to mirror human reproductive physiology. WIDER IMPLICATIONS OF THE FINDINGS To our knowledge, this study describes the first mouse model mimicking gender-affirming hormone therapy in peripubertal transmasculine youth. This model provides a tool for researchers studying the effects of GnRHa-T therapy on other aspects of reproduction, other organ systems and transgenerational effects. The model is supported by GnRHa suppressing puberty and maintaining acyclicity during T treatment, lower LH levels and absence of CL. The results also suggest GnRHa+T therapy in peripubertal female mice does not affect ovarian reserve, since the number of primordial follicles was not affected by treatment. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Michigan Institute for Clinical and Health Research grants KL2 TR 002241 and UL1 TR 002240 (C.D.C.); National Institutes of Health grants F30-HD100163 and T32-HD079342 (H.M.K.); University of Michigan Office of Research funding U058227 (A.S.); American Society for Reproductive Medicine/Society for Reproductive Endocrinology and Infertility grant (M.B.M.); and National Institutes of Health R01-HD098233 (M.B.M.). The University of Virginia Center for Research in Reproduction Ligand Assay and Analysis Core Facility was supported by the Eunice Kennedy Shriver NICHD/NIH grants P50-HD028934 and R24-HD102061. The authors declare that they have no competing interests. [ABSTRACT FROM AUTHOR]

Context: Adrenal-derived 11-oxygenated androgens (11oAs) are known important contributors to human physiology and disease but have not been studied in pregnancy. Objective: We characterize 11oAs in normal human pregnancy and neonatal period and assess the ratios between 11oAs and compare with ratios of other steroids that undergo placental metabolism. Design: Prospective cohort study, 2010-2018. Setting: Academic institution. Patients: Pairs of pregnant women and newborns (n = 120) were studied. Inclusion criteria were maternal age between 18 and 42 years old, spontaneous singleton pregnancies, and intention to deliver at University of Michigan. Intervention: Maternal venous blood was collected during first trimester and at term. Neonatal cord blood was collected following delivery. Steroids were measured via liquid chromatography-tandem mass spectrometry. Main Outcome Measures: Levels of 11ß-hydroxyandrostenedione (11OHA4), 11-ketoandrostenedione (11KA4), 11ß-hydroxytestosterone, and 11-ketotestoterone (11KT) in maternal first trimester, maternal term, and neonatal cord blood were compared. 11OHA4-to-11KA4 ratios were correlated with cortisol-to-cortisone ratios. Results: Dominant 11oAs in pregnancy and the cord blood are 11OHA4 and 11KA4, compared to 11OHA4 and 11KT in adult men and nonpregnant women. We found a rise in 11oA concentrations, particularly 11KA4, from first to third trimester. In cord blood, the concentration of 11KA4 exceeded those of both 11OHA4 and 11KT, reflecting placental 11ß-hydroxysteroid dehydrogenase type 2 (11ßHSD2) and 17ß-hydroxysteroid dehydrogenase (17ßHSD2) activities, respectively. 11OHA4-to-11KA4 ratios are concordant with cortisol-to-cortisone ratios across all maternal and fetal compartments, reflecting placental 11ßHSD2 activity. Conclusions: Placental 17ßHSD2 activity defends the fetus against the androgen 11KT. Our normative values may be used in future studies of 11oAs in complicated pregnancies. [ABSTRACT FROM AUTHOR]

Prenatal testosterone (T)-treated female sheep manifest peripheral insulin resistance, ectopic lipid accumulation, and insulin signaling disruption in liver and muscle. This study investigated transcriptional changes and transcriptome signature of prenatal T excess–induced hepatic and muscle-specific metabolic disruptions. Genome-wide coding and noncoding (nc) RNA expression in liver and muscle from 21-month-old prenatal T-treated (T propionate 100 mg intramuscular twice weekly from days 30-90 of gestation; term: 147 days) and control females were compared. Prenatal T (1) induced differential expression of messenger RNAs (mRNAs) in liver (15 down, 17 up) and muscle (66 down, 176 up) (false discovery rate < 0.05, absolute log2 fold change > 0.5); (2) downregulated mitochondrial pathway genes in liver and muscle; (3) downregulated hepatic lipid catabolism and peroxisome proliferator-activated receptor (PPAR) signaling gene pathways; (4) modulated noncoding RNA (ncRNA) metabolic processes gene pathway in muscle; and (5) downregulated 5 uncharacterized long noncoding RNA (lncRNA) in the muscle but no ncRNA changes in the liver. Correlation analysis showed downregulation of lncRNAs LOC114112974 and LOC105607806 was associated with decreased TPK1 , and LOC114113790 with increased ZNF470 expression. Orthogonal projections to latent structures discriminant analysis identified mRNAs HADHA and SLC25A45 , and microRNAs MIR154A , MIR25 , and MIR487B in the liver and ARIH1 and ITCH and miRNAs MIR369 , MIR10A , and MIR10B in muscle as potential biomarkers of prenatal T excess. These findings suggest downregulation of mitochondria, lipid catabolism, and PPAR signaling genes in the liver and dysregulation of mitochondrial and ncRNA gene pathways in muscle are contributors of lipotoxic and insulin-resistant hepatic and muscle phenotype. Gestational T excess programming of metabolic dysfunctions involve tissue-specific ncRNA–modulated transcriptional changes. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is the most common hormonal disorder in females of reproductive age. Hypersecretion of luteinizing hormone (LH), partly due to increased pituitary sensitivity to gonadotrophin-releasing hormone (GnRH), is a significant cause of infertility in women with PCOS. Moreover, obesity amplifies the severity of reproductive dysfunction in PCOS. In sheep, testosterone (T) excess during gestational days (GD) 30 to 90 results in GnRH-mediated LH hypersecretion and recapitulates the PCOS phenotype. This study investigated 1) if midgestation (GD 60 to 90) is the susceptibility window for programming pituitary hypersensitivity to GnRH, and 2) the contribution of postnatal obesity in modulating LH responsiveness to GnRH. Suffolk ewes received T propionate (T; 100 mg i.m.) or corn oil (C; vehicle) twice weekly from GD 60 to 90 (term = 147 d). At 5 mo of age, T lambs were assigned randomly to either a maintenance (100% of NRC requirements) or overfed diet (130% of NRC requirements), and Control lambs were fed the maintenance diet. During the anestrous period (late summer), ewes (n = 8/group; ~17 mo of age) received a GnRH bolus injection (2 ng/kg) intravenously every 1.5 h and blood samples were collected at 15-min intervals for a 6-h period. Despite animals being in seasonal anestrous, few endogenous LH pulses were evident during the 6 h-sampling period. To avoid confounding, only clear responses to GnRH challenge that occurred within 15 to 45 min after each GnRH injection were considered for further analyses. Mean number of exogenous GnRH-induced LH responses that met these criteria did not differ between groups and averaged 1.81 ± 0.27 pulses/animal. The parameters of these GnRH-induced responses were analyzed as one-way ANOVA with Tukey's HSD post-hoc analysis. Mean LH pulse peak was greater (P < 0.05) in T overfed ewes (4.59 ± 0.49 ng/mL) compared with T maintenance (2.19 ± 0.61 ng/mL) and Control ewes (2.58 ± 0.53 ng/mL). Additionally, amplitude of LH pulses was greater (P < 0.05) in T overfed ewes (2.66 ± 0.39 ng/mL) compared with T maintenance (1.03 ± 0.48 ng/mL) and tended (P = 0.089) to be greater in T overfed compared with Control ewes (1.41 ± 0.42 ng/mL). LH pulse peak and amplitude in T maintenance did not differ from Control ewes. In conclusion, failure of GD 60 to 90 T treatment to increase GnRH responsiveness as opposed to our earlier finding of increased responsiveness in GD 30 to 90 T-treaded sheep indicates that the susceptibility window for programming pituitary hypersensitivity to GnRH lies between GD 30 to 60. Postnatal obesity may act as an independent activational signal in amplifying the pituitary sensitivity to GnRH in female sheep. This premise is supported by observations that obesity exacerbates pituitarymediated LH hypersecretion in women with PCOS. Research support: NIH-NICHD (R01HD099096). [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is the leading cause of anovulatory infertility in women of reproductive age. Women with PCOS exhibit reduced sensitivity of the GnRH neuronal system to the inhibitory effects of both progesterone and estradiol. Additionally, obesity amplifies the severity of the PCOS phenotype. In sheep, testosterone (T) excess during gestational days (GD) 30-90 and 60-90 reduces neuroendocrine sensitivity to the progesterone negative feedback and recapitulates the PCOS phenotype. This study investigated the contribution of postnatal obesity in amplifying or mitigating the effects of midgestational T excess in disrupting the responsiveness to progesterone negative feedback in sheep. Suffolk ewes received T propionate (T; 100 mg i.m.) or corn oil (CO; vehicle) twice weekly from GD 60-90 (term = 147 d). At 5 mo of age, F1 T lambs were assigned randomly to either a maintenance (100% of NRC requirements) or overfed diet (130% of NRC requirements) and control lambs were fed the maintenance diet. At 22 mo of age, F1 ewes (n = 8/group) were synchronized with two injections of PGF2α 11 d apart. After the second PGF2α administration, blood samples were collected daily for 14 d and progesterone concentrations were determined via radioimmunoassay. Ewes that were confirmed to be cycling and in the mid-luteal phase based on progesterone concentrations (progesterone = 1 ng/ml on day 10 and = 0.5 ng/ml on days 8-9 and 11-12) were used for LH pulse characterization. On day 10 after PGF2α synchronization (mid-luteal phase), blood samples were collected every 15 min for 6 h to characterize LH pulsatile secretion via radioimmunoassay. Data were analyzed as one-way ANOVA with Tukey's HSD post-hoc analysis. Frequency of LH pulses was greater (P < 0.05) in T maintenance (3.75 ± 0.41 pulses/6h) and T overfed ewes (3.50 ± 0.34 pulses/6h) compared with controls (2.00 ± 0.37 pulses/6 h). Luteinizing hormone pulse amplitude was greater (P < 0.05) in T overfed (2.03 ± 0.15 ng/mL) compared with T maintenance (1.44 ± 0.17 ng/mL), but not to controls (1.74 ± 0.21 ng/mL). Also, average LH concentration was greater (P < 0.05) in T overfed (2.03 ± 0.24 ng/mL), but not T maintenance (1.31 ± 0.35 ng/mL), compared with controls (0.93 ± 0.30 ng/mLl). In conclusion, these findings demonstrate the activational role of postnatal obesity in amplifying prenatal T-induced alterations in tonic LH secretion during progesterone negative feedback. The activational effect of postnatal obesity in increasing LH secretion and consequently thecal androgen production is likely a contributor to the severity of hyperandrogenic status in women with PCOS. Research support: NIH-NICHD (R01HD099096). [ABSTRACT FROM AUTHOR]

The burden of adverse pregnancy outcomes such as preterm birth and low birth weight is considerable across the world. Several risk factors for adverse pregnancy outcomes have been identified. One risk factor for adverse pregnancy outcomes receiving considerable attention in recent years is gestational exposure to endocrine-disrupting chemicals (EDCs). Humans are exposed to a multitude of environmental chemicals with known endocrine-disrupting properties, and evidence suggests exposure to these EDCs have the potential to disrupt the maternal-fetal environment culminating in adverse pregnancy and birth outcomes. This review addresses the impact of maternal and fetal exposure to environmental EDCs of natural and man-made chemicals in disrupting the maternal-fetal milieu in human leading to adverse pregnancy and birth outcomes—a risk factor for adult-onset noncommunicable diseases, the role lifestyle and environmental factors play in mitigating or amplifying the effects of EDCs, the underlying mechanisms and mediators involved, and the research directions on which to focus future investigations to help alleviate the adverse effects of EDC exposure. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is a prevalent endocrine condition characterized by a range of endocrine, reproductive, and metabolic abnormalities. At present, management of women with PCOS is suboptimal as treatment is only symptomatic. Clinical and experimental advances in our understanding of PCOS etiology support a pivotal role for androgen neuroendocrine actions in PCOS pathogenesis. Hyperandrogenism is a key PCOS trait and androgen actions play a role in regulating the kisspeptin-/neurokinin B-/dynorphin (KNDy) system. This study aimed to investigate if targeted antagonism of neurokinin B signaling through the neurokinin 3 receptor (NK3R) would reverse PCOS traits in a dihydrotestosterone (DHT)-induced mouse model of PCOS. After 3 months, DHT exposure induced key reproductive PCOS traits of cycle irregularity and ovulatory dysfunction, and PCOS-like metabolic traits including increased body weight; white and brown fat pad weights; fasting serum triglyceride and glucose levels, and blood glucose incremental area under the curve. Treatment with a NK3R antagonist (MLE4901) did not impact the observed reproductive defects. In contrast, following NK3R antagonist treatment, PCOS-like females displayed decreased total body weight, adiposity, and adipocyte hypertrophy, but increased respiratory exchange ratio, suggesting NK3R antagonism altered the metabolic status of the PCOS-like females. NK3R antagonism did not improve circulating serum triglyceride or fasted glucose levels. Collectively, these findings demonstrate that NK3R antagonism may be beneficial in the treatment of adverse metabolic features associated with PCOS and support neuroendocrine targeting in the development of novel therapeutic strategies for PCOS. [ABSTRACT FROM AUTHOR]

Context: Steroids play an important role in fetal development and parturition. Gestational exposures to endocrine-disrupting chemicals (EDCs) affect steroidal milieu and pregnancy outcomes, raising the possibility of steroids serving as biomarkers. Most studies have not addressed the impact of EDC mixtures, which are reflective of real life scenarios.Objective: Assess the association of maternal and neonatal steroids with pregnancy outcomes and early pregnancy EDC levels.Design: Prospective analysis of mother-infant dyads.Setting: University hospital.Participants: 121 mother-infant dyads.Main Outcome Measures: The associations of maternal and neonatal steroidal hormones from 121 dyads with pregnancy outcomes, the associations of first trimester EDCs individually and as mixtures with maternal and neonatal steroids in a subset of 56 dyads and the influence of body mass index (BMI), age, and offspring sex in modulating the EDC associations with steroids were determined.Results: Steroid-specific positive or negative associations with pregnancy measures were evident; many maternal first trimester EDCs were negatively associated with estrogens and positively with androgen/estrogen ratios; EDC-steroid associations were influenced by maternal age, pre-pregnancy BMI, and fetal sex; and EDCs individually and as mixtures showed direct and inverse fetal sex-dependent associations with maternal and neonatal steroids.Conclusions: This proof-of-concept study indicates association of steroids with pregnancy outcomes depending on maternal age, prepregnancy BMI, and fetal sex, with the effects of EDCs differing when considered individually or as mixtures. These findings suggest that steroidal hormonal measures have potential to serve as biomarkers of impact of EDC exposures and pregnancy outcome. [ABSTRACT FROM AUTHOR]

Ovarian tissue cryopreservation and banking provides a fertility preservation option for patients who cannot undergo oocyte retrieval; it is quickly becoming a critical component of assisted reproductive technology programs across the world. While the transplantation of cryopreserved ovarian tissue has resulted in over 130 live births, the field has ample room for technological improvements. Specifically, the functional timeline of grafted tissue and each patient's probability of achieving pregnancy is largely unpredictable due to patient-to-patient variability in ovarian reserve, lack of a reliable method for quantifying follicle numbers within tissue fragments, potential risk of reintroduction of cancer cells harbored in ovarian tissues, and an inability to control follicle activation rates. This review focuses on one of the most common physiological techniques used to study human ovarian tissue transplantation, xenotransplantation of human ovarian tissue to mice and endeavors to inform future studies by discussing the elements of the xenotransplantation model, challenges unique to the use of human ovarian tissue, and novel tissue engineering techniques currently under investigation. [ABSTRACT FROM AUTHOR]

Early-life exposures to environmental insults can misprogram development and increase metabolic disease risk in a sex-dependent manner by mechanisms that remain poorly characterized. Modifiable factors of increasing public health relevance, such as diet, psychological stress, and endocrine-disrupting chemicals, can affect glucocorticoid receptor signaling during gestation and lead to sex-specific postnatal metabolic derangements. Evidence from humans and animal studies indicate that glucocorticoids crosstalk with sex steroids by several mechanisms in multiple tissues and can affect sex-steroid–dependent developmental processes. Nonetheless, glucocorticoid sex-steroid crosstalk has not been considered in the glucocorticoid-induced misprogramming of metabolism. Herein we review what is known about the mechanisms by which glucocorticoids crosstalk with estrogen, androgen, and progestogen action. We propose that glucocorticoid sex-steroid crosstalk is an understudied mechanism of action that requires consideration when examining the developmental misprogramming of metabolism, especially when assessing sex-specific outcomes. [ABSTRACT FROM AUTHOR]

More than 1 out of 10 women worldwide are diagnosed with polycystic ovary syndrome (PCOS), the leading cause of female reproductive and metabolic dysfunction. Despite its high prevalence, PCOS and its accompanying morbidities are likely underdiagnosed, averaging > 2 years and 3 physicians before women are diagnosed. Although it has been intensively researched, the underlying cause(s) of PCOS have yet to be defined. In order to understand PCOS pathophysiology, its developmental origins, and how to predict and prevent PCOS onset, there is an urgent need for safe and effective markers and treatments. In this review, we detail which animal models are more suitable for contributing to our understanding of the etiology and pathophysiology of PCOS. We summarize and highlight advantages and limitations of hormonal or genetic manipulation of animal models, as well as of naturally occurring PCOS-like females. [ABSTRACT FROM AUTHOR]

Environmental contamination with hexavalent chromium (CrVI) is a growing problem both in the United States and developing countries. Hexavalent chromiumis widely used in numerous industries. Environmental exposure to CrVI adversely affects pregnancy outcomes and subsequent health of 2 generations, resulting in higher pregnancy loss, spontaneous abortion and low birth rate. Pregnant women exposed to CrVI through occupational settings experience increased risk of spontaneous abortion, stillbirth, preterm birth, and neonatal death. Children of the CrVI exposed women experience respiratory problems, perinatal jaundice, and increased birth defects. Because placental dysfunction may have a role in such adverse pregnancy outcome, we tested the hypothesis that environmental Cr exposure in pregnant women results in Cr accumulation in the human placenta, which could increase placental oxidative stress by disrupting antioxidant machinery and inducing apoptosis. Studies using frozen, deidentified human term placenta samples indicated that: (1) Cr accumulates in human term placenta tissues and (2) increase in Cr accumulation is positively correlated with oxidative stress and apoptotic markers, and altered antioxidants levels. Interestingly, there was a sexual dimorphism in the correlation between Cr accumulation and oxidative stress, and expression of apoptotic and antioxidant markers. Mechanistic in vitro studies using human trophoblast cells BeWo confirmed the detrimental effects of Cr in altering antioxidant genes. For the first time, this study provides evidence in support of a positive correlation between Cr accumulation in the human placenta and accelerated oxidative stress, with a gender bias toward the male sex. [ABSTRACT FROM AUTHOR]

Prenatal testosterone excess causes reproductive perturbations in sheep that recapitulate those seen in women with polycystic ovary syndrome (PCOS). Obesity has a significant role in the development and severity of the PCOS phenotype. Our objective was to investigate the effects of testosterone excess from gestational days (GD) 60-90 (unlike the GD 30-90 model, these animals are not virilized) and postnatal body weight (BW) gain on puberty in firstgeneration ewe lambs. Pregnant Suffolk ewes received testosterone propionate (T; 100 mg) or corn oil (C) i.m. twice weekly from GD 60-90 (term=147d). Ewe lambs were weaned ~3 mo of age. Control and T lambs were assigned to gain either 0.3 kg/d (C and T-maintenance) or 0.4 kg/d (T-overfed). Maintenance diet was designed to promote optimal growth without excess fat deposition. Overfed ration was designed to achieve a BW ~30% above that of maintenance. Progesterone concentrations were measured via radioimmunoassay in blood samples collected twice weekly from ewe lambs (n=15/group) during the first breeding season. Puberty was defined as when progesterone concentrations were < 0.5 ng/mL for four consecutive samples followed by three consecutive samples =0.5 ng/mL. Six animals (C, n=1; T-maintenance, n=3; T-overfed, n=2) did not attain puberty during the study and puberty was assigned as last day of sampling. Average daily gain was not different among treatments (C, 0.23±0.02kg; T-maintenance, 0.25±0.01kg; T-overfed, 0.27±0.02kg). Age at puberty did not differ between groups (C, 274.6±9.9d; T-maintenance, 270.0±11.3d; T-overfed, 266.0±10.2d). Similarly, BW at puberty did not differ across treatments (C, 50.44±2.2kg; T-maintenance, 52.5±2.4kg; T-overfed, 57.3±2.5kg). In conclusion, unlike GD 30-90 exposure which advanced puberty, GD 60-90 exposure did not affect age and BW at puberty in ewe lambs. Collectively, these studies suggest that GD 30-60 is a critical developmental window in which prenatal testosterone excess advances puberty in female sheep. Research support: NIH-NICHD (R01HD099096). [ABSTRACT FROM AUTHOR]

Serum concentrations of inhibin A, inhibin B, activin A and follistatin were determined using two-site enzyme-linked immunosorbent assays (ELISA) during pubertal ovarian development in 28 girls and five follicular phase women. Blood obtained every 15 to 20 min overnight was pooled for peptide determination. Serum inhibin A concentrations increased in mid puberty, exhibiting positive correlations with bone age (r = 0.527, P = 0.0016) and oestradiol concentrations (r = 0.581, P = 0.0005). Inhibin B concentrations peaked in mid puberty and declined thereafter, but remained greater than concentrations seen in prepubertal girls, and correlating positively with oestradiol (r = 0.362, P = 0.046) and follicle stimulating hormone (FSH) concentrations (r = 0.369, P = 0.038). Total activin A concentrations did not vary significantly across pubertal stages. Total follistatin concentrations, determined by radioimmunoassay, decreased with advancing puberty, exhibiting negative correlations with bone age (r = -0.634, P = 0.0001) and oestradiol concentration (r = -0.687, P = 0.0001). Follistatin concentrations determined by an ELISA specific for follistatin 288 were greatest in mid-pubertal girls, but concentrations in late puberty were less than those in early puberty. The free follistatin assay indicated that all circulating follistatin was activin-bound. These results suggest that significant changes in serum concentrations of FSH-regulatory peptides accompany the onset of puberty. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented which discusses the need for guidelines that require appropriate positive controls in endocrine disruption research as revealed by a flawed experimental design.