Plasma Estrogen Levels Research Articles

Vinpocetine facilitates the anti-amnesic activity of estrogen-receptor alpha agonist in bilateral ovariectomy-challenged animals

The fluctuation in plasma estrogen level influences the cognitive function in the females. The specific estrogen receptor alpha (ERα) agonist, (4,4′,4″-(4-propyl-[1 H] pyrazole-1,3,5-triyl) tris phenol (PPT), is reported to exhibit therapeutic activity similar to that of estrogen replacement therapy. However, the former can also exert cyclic adenosine monophosphate (cAMP)-dependent carcinogenic activity in the uterus of the ovariectomized animals. Moreover, there is no report of cGMP on ERα-mediated phosphorylation of Akt in the experimental condition. Vinpocetine increases the rate of formation of cGMP than cAMP in several tissues. Hence, the present study evaluated the neuroprotective effect of vinpocetine with or without PPT against ovariectomy-induced dementia in experimental rodents. The condition of estrogen insufficiency was induced in female rats through bilateral ovariectomy on day-1 (D-1) of the experimental schedule. Vinpocetine (20 mg/kg) and PPT attenuated ovariectomy-induced cognitive deficits in behavioral tests and increase in body weight in the rodents. Vinpocetine and PPT increased the cholinergic function and the ratio of cGMP/cAMP in the hippocampus, pre-frontal cortex and amygdala of the ovariectomized animals. Further, ovariectomy-induced decrease in the extent of phosphorylation of ERα in all brain regions was attenuated with the monotherapy of either vinpocetine or PPT. Interestingly, the combination of vinpocetine and PPT exhibited better effectiveness than their monotherapy. However, vinpocetine attenuated the PPT-induced increased level of phosphorylated Akt in discrete brain regions and weight of uterus of these rodents. Hence, the combination could be considered as a better alternative candidate with minimal side effects in the management of estrogen insufficiency-induced disorders.

SUN-239 Effects of High-Fat Diet-Induced Obesity on Pulsatile LH Secretion and Hypothalamic KISS1 Expression in Female Rats

Female obesity is associated with menstrual dysfunction leading to anovulation and infertility. It has recently been reported obesity-induced infertility is involved in the dysfunction of a kisspeptin neuron, a key player in reproduction via direct stimulation of gonadotropin releasing hormone (GnRH) and subsequent gonadotropin release in mammalian species. Previous studies reported that obesity due to high-fat diet (HFD) for 8 months induced a disruption in estrous cyclicity, caused by a decrease in Kiss1 (coding kisspeptin) expression in the hypothalamic arcuate nucleus (ARC) in female rodents. Here we showed the effects of shorter-term (4 months) HFD on pulsatile LH secretion and hypothalamic Kiss1 expression to show pathogenic mechanism underlying obesity-induced infertility. Female Wistar-Imamichi strain rats (7 weeks old) fed on either a standard diet (10% calories from fat) or a high-fat diet (45% calories from fat) for 4 months. Estrous cyclicity and body weight were monitored regularly. All animals were implanted with a jugular catheter and collected blood samples to analyze pulsatile LH secretion, after a week of the ovariectomy with low-dose replacement estradiol to negate influence of changes in ovarian steroid levels and mimic diestrous levels of plasma estrogen. On the next day of the blood sampling, rats were perfused with 0.05 M PBS followed by 4% paraformaldehyde and their brains were collected for in situ hybridization of Kiss1 and Gnrh1. The HFD-fed rats showed progressive increases in body weight, along with hyperphagia and adipose tissue accumulation, compared with control animals. Fifty-eight percent of the HFD-fed rats exhibited irregular estrous cycles, whereas remaining HFD-fed rats showed regular cycles. Two out of 7 rats showing HFD-induced irregular estrous cycles exhibited profound suppression of the LH pulse frequency and the number of Kiss1-expressing cells in the ARC, whereas remaining HFD-fed rats showed normal LH pulses and ARC Kiss1 expressions. The number of Kiss1-expressing cells in the ARC had close positive correlation with LH pulse frequency (R2=0.6872, P<0.001) in both groups. Additionally, the number of Kiss1- or Gnrh1-expressing cells in the anteroventral periventricular nucleus or the preoptic area, were comparable between groups. Taken together, our finding reveals the possibility that irregular menstruation was also induced by changes in the kisspeptin-GnRH independent pathway during the incipient stage of obese infertility.

An Ultrasensitive Routine LC-MS/MS Method for Estradiol and Estrone in the Clinically Relevant Sub-Picomolar Range.

BackgroundCurrent analytical routine methods lack the sensitivity to monitor plasma estrogen levels in breast cancer patients treated with aromatase inhibitors. Such monitoring is warranted for premenopausal patients treated with an aromatase inhibitor and an LH-releasing hormone analogue in particular. Therefore, we aimed to develop a routine tandem mass spectroscopy combined with liquid chromatography (LC-MS/MS) method for estradiol (E2) and estrone (E1) for use in the sub-picomolar range.MethodCalibrators, quality controls (QC), or serum samples were spiked with isotope-labeled internal standard and purified by liquid-liquid extraction. The reconstituted extracts were analyzed by LC-MS/MS in negative electrospray ionization mode. QCs at 6 levels made from pooled patient sera were used to validate the accuracy, sensitivity, and precision of the method.ResultsWe achieved limits of quantification of 0.6 pmol/L (0.16 pg/mL) for E2 and 0.3 pmol/L (0.07 pg/mL) for E1. The coefficient of variation was below 9.0% at all QC levels for E2 (range, 1.7-153 pmol/L), and below 7.8% for E1 (range, 1.7-143 pmol/L). The method is traceable to the E2 reference standard BCR576. Reference ranges for E2 and E1 in healthy, postmenopausal women were obtained, for E2: 3.8 to 36 pmol/L, for E1: 22 to 122 pmol/L. We measured and confirmed ultra-low E2 and E1 concentrations in sera from patients on the aromatase inhibitors letrozole or exemestane.ConclusionThis ultrasensitive LC-MS/MS method is suitable for routine assessment of serum E1 and E2 levels in breast cancer patients during estrogen suppression therapy. The method satisfies all requirements for measurement of E2 in the clinical setting as stated by the Endocrine Society in 2013.PrecisWe report an ultrasensitive LCMS/MS routine assay that measures pretreatment and suppressed levels of estradiol/estrone during aromatase inhibitor treatment of postmenopausal breast cancer patients.

The Role of The G Protein Coupled Estrogen Receptor in Endothelial Progenitor Cell Number and Function

Microvascular dysfunction is a key component of cardiovascular disease and plasma estrogen levels have been shown to impact vascular function. Endothelial progenitor cells (EPCs) are a stem cell population that support the integrity of the microvasculature and show increased proliferation in response to estradiol exposure when assessed in vitro. The plasma concentration of EPCs negatively correlates with incidence of stroke and coronary artery disease. In vivo studies of the effect of estradiol exposure on EPC number are complicated by the presence of other estrogens and complex estrogen signaling pathways. In EPCs, pathways that are activated via nuclear estrogen receptors are well investigated and pro‐angiogenic. Recent evidence suggests that other estrogens may be biologically active through a G protein coupled estrogen receptor, GPER, and that activation of GPER may have a modulatory relationship with nuclear estrogen receptor pathways. Investigation of GPER in EPCs is crucial to understanding the effects of estrogens on EPC health and vascular function.Here, we present the first evidence that GPER is present in human EPCs via immunohistochemistry and PCR analysis. We also investigated the role of agonism and antagonism of GPER in human EPC proliferation, migration, adhesion and paracrine function. Human EPCs were defined as cells that are isolated from bone marrow or peripheral blood mononuclear cell fractions, display typical endothelial cell (EC) morphology and are positive for cell surface proteins: VEGFR2, CD133, cKIT, CD34, and Dil‐ac‐LDL uptake. We assessed GPER expression via qPCR and immunocytochemistry on EPCs without hormone treatment. The proliferation assays were performed over a 24 hour exposure to 100 nM estradiol in combination with one of the following: 0.1, 1 and 10 μM concentrations of GPER agonist, G1 or GPER antagonist, G36. In our migration, adhesion and proliferation assays, EPCs were exposed to 100 nM estradiol in combination with one of the GPER modulator concentrations (as described above) for 24 hours and assessed thereafter. Migration was assessed via Transwell migration assay. To assay adhesion 1000 EPCs were seeded onto a 96 well plate, incubated for 4 hours and rinsed. Wells were then imaged and adherent cells were quantified. EPC paracrine function was assessed by tube formation assay. In this assay, treated EPCs were added to an endothelial cell tube formation assay to assess their ability to augment endothelial cell tubulogenesis.Our results show that GPER is expressed on human EPCs. In vitro EPC proliferation, migration, adhesion and paracrine function was enhanced by antagonism of GPER in a dose dependent manner. In vitro EPC proliferation, migration, adhesion and paracrine function was attenuated by agonism of GPER in a dose dependent manner. To investigate candidates for activators of this modulatory pathway, further studies will investigate estrone, the most prominent estrogen in males and postmenopausal females, and its action at GPER.

Down-regulation of ER-α36 mRNA in serum exosomes of the patients with hepatocellular carcinoma.

Down-regulation of ER-α36 mRNA in serum exosomes of the patients with hepatocellular carcinoma.

Sex Differences in Metabolic Responses to Chronic Immobilization Stress in Rats

Abstract Background Responses to stress could range from homeostatic variations to life-threatening effects depending on the type, timing and severity of the applied stimulus. Gender is accompanied by variations in oxidative stress, which causes the development of metabolic diseases. Under physiological conditions, females were found to be less susceptible to oxidative stress. Aim of work: This study was conducted to highlight the sex differences in the metabolic responses to chronic immobilization stress in rats, and to elucidate the possible underlying mechanisms. Materials and Methods Forty adult Wistar rats of both sexes; were randomly divided into 2 main groups: control group and stressed group, each of which was further subdivided into male and female groups. Stressed groups were exposed to chronic immobilization for 4 weeks. All rats were subjected to determination of body mass index, visceral fat weight, absolute and relative weights of liver and pancreas, plasma glucose, glucose uptake by diaphragm, glucose output by kidneys, lipid profile and plasma levels of insulin, leptin and sex hormones, malodialdehyde (MDA), total antioxidant capacity (TAC) and nitrite. HOMA-B and HOMA-IR were calculated. Also, caspase 3 was assessed in pancreas by immunohistochemistry. Results Stressed male rats showed lower BMI, higher relative liver weight, dyslipidemia, fasting hyperglycemia, higher glucose output by kidneys, lower glucose uptake by diaphragm, HOMA-B and plasma levels of insulin, testosterone and TAC and higher plasma estrogen and MDA levels compared to the control male group. Compared to the control female group, stressed female rate exhibited hyperglycemia, hypoinsulinemia, dyslipidemia, oxidative stress, higher plasma sex hormones. Compared to stressed male rats, stressed female group showed significantly higher BMI percentage change and plasma levels of TAC, estrogen and testosterone, but significantly lower absolute liver weight, glucose output by the kidneys, plasma levels of total cholesterol and triglycerides, and atherogenic index. Conclusion Chronic immobilization stress imposes greater hyperglycemic and hyperlipidemic status in males than in females. The altered sex hormonal pattern and lowered antioxidant defences could be contributory mechanisms

EVALUATION OF CHANGES IN CARDIORESPIRATORY FUNCTIONS DURING DIFFERENT PHASES OF THE MENSTRUAL CYCLE IN YOUNG WOMEN

Introduction: Menstrual cycle or menstruation involved discharge of sanguinous fluid and a sloughing of uterine wall. In women menstruation occurs at regular intervals on an average of 28 days, although most women gave a history of regular intervals of 28 to 30 days. About 10% -15% of women showed cycle at the precise 28 ± 2 days intervals when menstrual calendar was utilized. Normally in young women in different phases of ovarian cycles the plasma levels of estrogen vary. Ovulation occurs in the first 12-13th day of menstrual cycle, which is termed estrogen surge and second occurs in mid-luteal phase. During mid cycle or follicular phase of menstrual cycle the plasma concentration of progesterone is very low about 0.9 ng/mL. its level starts rising owing to secretion from the granulose cells. During luteal phase progesterone level reaches its peak value of 18 ng/mL and its level fall to a minimum value toward the end of the cycle. Estrogen affects local and systemic vasodilation. The menstrual cycle envelops two fundamental stages, the follicular stage (FP) and the luteal stage (LP). The follicular stage can part advance into two substages; the early FP, which is characterised with moo concentrations of both the key hormones estrogen and progesterone; and the mid FP where estrogen is tall autonomously from progesterone. The LP is epitomized by tall concentration of both estrogen and progesterone. These two fundamental stages are isolated by a soak surge in luteinizing hormone activating ovulation. These recurrent changes are said to be frequency unsurprising while long time. Aim: The main aim of this study is to evaluate the Cardiorespiratory functions changes during different Phases of Menstrual Cycle. &#x0D; Material and methods: In this study, 20 with normal weight, 20 with obese and 20 with overage were included and taken them as a sample size. In this study all the young women those were recruited as a sample size are unmarried, undergraduate female student with the between the age group of 18-22years, having regular 28+6 days menstrual cycle for at least last 6months prior to this study. For the collection of data all the participants were instructed to attend the physiology lab department during each of three different phases. Day-2 during menstrual phase, Day-7, during follicular phase and Day-22 during luteal phase and the following parameters were recorded as Anthropometric measurements, measuring of pulse rate and blood pressure and cardiac efficiency test.&#x0D; Result: In general, work out proficiency changed essentially amid the distinctive stages of the menstrual cycle with the most elevated amid luteal stage and least amid menstrualo stage. There was no critical contrast in impact test amid menstrual stage, follicular stage and luteal stage of menstrual cycle among three bunches of people.&#x0D; Conclusion: We have watched noteworthy increment in cardiac and respiratory proficiency within the luteal stage of the menstrual cycle in ordinary weight people. Lower wellness levels were watched in overweight and stout females. In this manner hone of customary work out and admissions of solid slim down which offer assistance in lessening the weight and in turn the BMI will offer assistance in improving the physical wellness of the people.&#x0D; Keywords: Cardiorespiratory, Menstrual cycle, expiratory blast test

Estrogen accelerates heart regeneration by promoting the inflammatory response in zebrafish.

Sexual differences have been observed in the onset and prognosis of human cardiovascular diseases, but the underlying mechanisms are not clear. Here, we found that zebrafish heart regeneration is faster in females, can be accelerated by estrogen and is suppressed by the estrogen-antagonist tamoxifen. Injuries to the zebrafish heart, but not other tissues, increased plasma estrogen levels and the expression of estrogen receptors, especially esr2a. The resulting endocrine disruption induces the expression of the female-specific protein vitellogenin in male zebrafish. Transcriptomic analyses suggested heart injuries triggered pronounced immune and inflammatory responses in females. These responses, previously shown to elicit heart regeneration, could be enhanced by estrogen treatment in males and reduced by tamoxifen in females. Furthermore, a prior exposure to estrogen preconditioned the zebrafish heart for an accelerated regeneration. Altogether, this study reveals that heart regeneration is modulated by an estrogen-inducible inflammatory response to cardiac injury. These findings elucidate a previously unknown layer of control in zebrafish heart regeneration and provide a new model system for the study of sexual differences in human cardiac repair.

Sex Differences in Metabolic Responses to Chronic Immobilization Stress in Rats

Background: Responses to stress could range from homeostatic variations to life-threatening effects. Gender is accompanied by variations in oxidative stress that are implicated in the development of metabolic diseases. Females were found to be less susceptible to oxidative stress. Aim: to clarify the differences in metabolic responses to chronic immobilization stress in both rat sexes, and to elucidate the possible underlying mechanism. Methods: 40 adult albino rats of both sexes were divided into 2 main groups: control and stressed groups, each was subdivided into male and female groups. Stressed groups were exposed to immobilization for 4 weeks. All rats were subjected to estimation of body mass index percentage change (BMI%), visceral fat weight (VFW), glycemic parameters, lipid profile, plasma insulin, leptin, sex hormones, malondialdehyde (MDA), total antioxidant capacity (TAC) and nitrite. HOMA-B and HOMA-IR were calculated, Caspase-3 was assessed in pancreas by immunohistochemistry. Results: Stressed male rats showed lower BMI%, VFW, dyslipidemia, hyperglycemia, higher glucose output by kidneys, lower glucose uptake by diaphragm, HOMA-B, plasma insulin, testosterone and TAC, with higher plasma estrogen and MDA levels compared to control male group. Compared to control females, stressed females exhibited lower VFW, hyperglycemia, hypoinsulinemia, dyslipidemia, lower plasma TAC and HOMA-B, with higher nitrite and sex hormones. Compared to stressed males, stressed females showed higher BMI%, plasma TAC and estrogen, but lower glucose output by kidneys, dyslipidemia and testosterone. Conclusion: Chronic immobilization stress imposes greater metabolic derangement in males than in females. The altered sex hormones and lowered antioxidants could be contributory mechanisms.

The Effects of Nicotine on Foetal Loss, Postnatal Growth and Plasma Oestrogen and Progesterone Levels in Rats

Introduction: The present study aims to investigate the effects of nicotine on foetal loss, postnatal growth and corresponding levels of oestrogen and progesterone in pregnant rats. Method: Subcutaneous injection of nicotine tartrate (7.5 mg/kg/day) was administered to groups of pregnant rats; with treatment scheduled from day 1 through day 5, day 5 through day 9 or day 1 through day 9 of pregnancy. On day 10 of pregnancy, laparotomy was performed to count the number of blastocyst implantation sites. During parturition, the number of viable pups was recounted and statistically compared with the controls. One group of rats which received nicotine from day 1 through day 9 of pregnancy was sacrificed on day 16 of pregnancy, and circulating levels of oestrogen and progesterone were measured. Upon delivery, the birth weight of the pups was measured, and their weights were recorded until weaning. Result: There was a significant increase in foetal loss particularly in rats which received nicotine from day 5 through day 9 and from day 1 through day 9 of pregnancy. There was also significantly lower birth weight of pups in all groups; however, this pattern did not continue until weaning. Plasma oestrogen level was significantly elevated with a significant decrease in the plasma progesterone level. Conclusion: Nicotine administration during pregnancy showed an increase in foetal loss with a corresponding increase in oestrogen and decrease in progesterone levels. Although the birth weight of the pups was low, there was catch-up growth in the pups.

Sildenafil promotes the anti-amnesic activity of estrogen receptor alpha agonist in animals with estrogen insufficiency

The cognitive function in the females is observed to modulate with the fluctuation in plasma estrogen level. The specific estrogen receptor alpha (ERα) agonist, (4,4′,4″-(4-propyl-[1H] pyrazole-1,3,5-triyl) tris phenol (PPT), exerts similar therapeutic activity to that of estrogen replacement therapy. It can also exert cyclic adenosine monophosphate (cAMP)-dependent carcinogenic activity in the uterus of the ovariectomized animals. However, there is no report of cGMP on the ERα-mediated phosphorylation of Akt in the experimental condition. Sildenafil increases the level of cGMP in most of the tissues including brain. Hence, the present study evaluated the therapeutic effect of Sildenafil with or without PPT in rats with experimentally-induced estrogen insufficiency. The condition of estrogen insufficiency was induced in female rats through bilateral ovariectomy on day-1 (D-1) of the experimental schedule. Sildenafil (1.0 and 10.0 mg/kg) and PPT attenuated ovariectomy-induced cognitive deficits in behavioural tests and increase in body weight in the rodents. Sildenafil and PPT increased the cholinergic function and the ratio of cGMP/cAMP in the hippocampus, pre-frontal cortex and amygdala of the animals. Further, the ovariectomy-induced decrease in the extent of phosphorylation of ERα in all the brain regions was attenuated with the monotherapy of either Sildenafil or PPT. Interestingly, the combination of Sildenafil and PPT exhibited better therapeutic effectiveness than their monotherapy. However, Sildenafil attenuated the PPT-induced increase in the level of expression of phosphorylated protein kinase-B (Akt) in the discrete brain regions and the weight of uterus of these rodents. Hence, it can be assumed that the combination could be a better therapeutic alternative with minimal side effect in the management of estrogen insufficiency-induced disorders.

Increased HDAC9 Expression is Associated with Decreased Estrogen in Female Patients with Intracranial Aneurysm

Background and purposeSubarachnoid hemorrhage is a devastating consequence of intracranial aneurysm (IA) rupture. Therefore early identification of patients with IA is important. Identification of biomarkers for IA will help improve diagnosis, the understanding of IA pathogenesis, and patient management. A risk allele (rs10230207), located nearby the histone deacetylase 9 (HDAC9) gene on chromosome 7, has been associated with IA incidence. HDAC9 can repress the transcription of estrogen receptors α and β (ESR1 and ESR2). We tested the hypothesis that lymphocytes from patients with IA will have increased HDAC9 and decreased estrogen receptor gene transcription compared to controls.MethodsImmortalized B‐lymphocytes from male and female patients with un‐ruptured IA (N=109) and population controls (N=85) were obtained from the NINDS repository and cultured in RPMI‐1640 medium supplemented with 10% fetal calf serum. Subject genomic DNA was genotyped for presence of the risk allele using TaqMan SNP genotyping assays directed toward rs10230207. HDAC9 and ESR gene expression were analyzed using TaqMan expression assays. In a separate study using subject case (N=23) and control (N=10) blood samples, HDAC9 and ESR2 transcriptional differences were confirmed in peripheral blood mononuclear cells. Plasma estrogen levels were also measured in these subjects.ResultsHDAC9 expression was increased in IA patient lymphoblasts compared to population controls (P= 0.0311) and was associated with the presence of the rs10230207 risk allele (P=0. 0235). Patients harboring the risk allele had an increased risk for IA (OR 9.1, 95% CI 3.6–23.1). While the risk allele puts both males and females at risk for IA, the risk of IA is larger for females (OR 23.9, 95% CI 5.4–105.4) compared to males (OR 5.9, 95% CI 2.7–13.2). Lymphoblasts from female subjects between 19–50 years (premenopausal) were further analyzed (N= 17 cases and 22 population controls). HDAC9 gene expression was increased (P=0.0243) and ESR2 expression was decreased (P= 0.0351) in premenopausal females with IA compared to premenopausal female population controls. Decreased plasma estrogen levels were also detected in the premenopausal female cases (N=7) compared to control (N=5) subjects (P =0.0015).ConclusionsThe presence of the rs10230207 risk allele was associated with increased expression of HDAC9 and decreased expression of ESR2 in case and control immortalized lymphoblasts. Furthermore, we found that female IA patients that had not yet undergone menopause had decreased plasma estrogen levels. Future studies are aimed at defining the positive and negative predictive values of estrogen levels and IA in female patients.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effect of vaginal fold prolapse occurrence in a pregnant bitch on parturition process

Vaginal prolapse is defined as a protrusion of edematous vaginal tissue into the vaginal lumen and often through the vulvar lips of the bitches. Vaginal prolapse is frequently related to the increase in plasma estrogen level during the proestrus, estrus period and at the end of the pregnancy. In the pregnant bitches, however, vaginal prolapse is a rare condition. The objective of this case was to determine the effect vaginal fold prolapse events occurred during the last period of pregnancy on parturition. This article describes a 1-year-old Dogo Argentino bitch, weighing 29kg, presented due to vaginal prolapse which occurred during the last trimester of pregnancy. On clinical examination, the case was diagnosed as vaginal fold prolapse with about diameter of 50mm. Transabdominal ultrasonography was performed to evaluate the bitch's pregnancy status and revealed live fetuses in the uterus. The bitch and fetuses were healthy in performed examinations. And then the vaginal mass was cleaned and placed into normal position. Blood samples were taken for hematological tests. The results of complete blood count were within normal range. Serum estradiol and progesterone levels were 6.93 pg/ml and 23.27 ng/ml, respectively. Parturition was started spontaneously 58 days after mating and a healthy puppy was born. Unborn puppies were detected and C-section was performed. Seven live puppies were removed from the uterus. In conclusion; it was determined that the vaginal fold prolapse event that occurred during the last period of pregnancy was no effect to start of parturition. And also, it was concluded that monitoring of the parturition process would be beneficial for the health of the mother and the puppies.

Localization of estrogen receptor ERα, ERβ and GPR30 on myenteric neurons of the gastrointestinal tract and their role in motility

Estrogen is well known to have a modulatory role on gastrointestinal tract, particularly through its interaction with nuclear estrogen receptors (ERs), alpha and beta (ERα/β). Recent functional studies also indicate that estrogen can activate a G-protein coupled estrogen receptor, GPR30, or GPER1. The present study was designed to identify either the presence or absence of nuclear ERs and GPR30 in the myenteric plexus of the stomach, duodenum, jejunum, ileum and colon of female and male mice. Immunofluorescence staining revealed a high expression of GPR30 in the cytoplasm but not within the nucleus of enteric neurons in female and male mice. ERβ localization was similar to GPR30, where it was expressed in cytoplasm of enteric neurons, but was absent from nuclei, opening up the possibility that ERβ and GPR30 might work together to manifest estrogenic effects. Comparatively, ERα was mainly located in the nuclei of enteric neurons. ERα, ERβ and GPR30 were also expressed in the cytoplasm of glial cells in the stomach and small intestine, but levels were lower in the colon. The expression nuclear:cytoplasm ratio of ERα was higher in male than female mice, which might relate to sex-dependent translocation of ERα from cytoplasm to nucleus in response to known plasma levels of estrogen. A functional study using isolated ileal segments showed that ERα, ERβ and GPR30 are involved in the neuronal-mediated contractions in female tissues, but only ERα was involved in male tissues. This may indicate although expression level was similar between males and females, the downstream mechanisms of ERβ and GPR30 could be different between sexes. The present study provides a rationale for the action of estrogen to modulate gastrointestinal function in health and disease in different sexes.

Vitamin B2 enhances development of puberty ovaries via regulation of essential elements and plasma endocrine hormones

Purpose: To investigate the effect of vitamin B2 (VB2) on ovarian development during puberty.Methods: Four groups of domestic hens (Jinghong-1 strain, 12 hens/group) were housed under standard conditions and fed basal diet with or without graded doses of VB2 (10 – 40 mg/kg). At 10 weeks old, 9 hens were sacrificed from each group. Plasma levels of AST, ALT, steroid hormones and growth hormones were determined. In addition, some essential mineral elements in the ovarian tissue of the hens were assayed.Results: Treatment with VB2 significantly improved ovary and liver organ indices (p &lt; 0.01), but had no deleterious effect on the liver. The different doses of VB2 exerted regulatory effects on homeostasis of essential elements in the ovary (p &lt; 0.01). Moreover, VB2 treatment elevated plasma levels of progesterone (PR) and estrogen (ES), suggesting that it might regulate steroid hormone levels.Conclusion: These results indicate that VB2 enhances the development of the ovaries during puberty.Keywords: Domestic hen, Ovarian development, Vitamin B2, Steroid hormones, Mineral elements

Estrogen Treatment Reverses Prematurity-Induced Disruption in Cortical Interneuron Population.

Development of cortical interneurons continues until the end of human pregnancy. Premature birth deprives the newborns from the supply of maternal estrogen and a secure intrauterine environment. Indeed, preterm infants suffer from neurobehavioral disorders. This can result from both preterm birth and associated postnatal complications, which might disrupt recruitment and maturation of cortical interneurons. We hypothesized that interneuron subtypes, including parvalbumin-positive (PV+), somatostatin-positive (SST+), calretinin-positive (CalR+), and neuropeptide Y-positive (NPY+) interneurons, were recruited in the upper and lower cortical layers in a distinct manner with advancing gestational age. In addition, preterm birth would disrupt the heterogeneity of cortical interneurons, which might be reversed by estrogen treatment. These hypotheses were tested by analyzing autopsy samples from premature infants and evaluating the effect of estrogen supplementation in prematurely delivered rabbits. The PV+ and CalR+ neurons were abundant, whereas SST+ and NPY+ neurons were few in cortical layers of preterm human infants. Premature birth of infants reduced the density of PV+ or GAD67+ neurons and increased SST+ interneurons in the upper cortical layers. Importantly, 17 β-estradiol treatment in preterm rabbits increased the number of PV+ neurons in the upper cortical layers relative to controls at postnatal day 14 (P14) and P21 and transiently reduced SST population at P14. Moreover, protein and mRNA levels of Arx, a key regulator of cortical interneuron maturation and migration, were higher in estrogen-treated rabbits relative to controls. Therefore, deficits in PV+ and excess of SST+ neurons in premature newborns are ameliorated by estrogen replacement, which can be attributed to elevated Arx levels. Estrogen replacement might enhance neurodevelopmental outcomes in extremely preterm infants.SIGNIFICANCE STATEMENT Premature birth often leads to neurodevelopmental delays and behavioral disorders, which may be ascribed to disturbances in the development and maturation of cortical interneurons. Here, we show that preterm birth in humans is associated with reduced population of parvalbumin-positive (PV+) neurons and an excess of somatostatin-expressing interneurons in the cerebral cortex. More importantly, 17 β-estradiol treatment increased the number of PV+ neurons in preterm-born rabbits, which appears to be mediated by an elevation in the expression of Arx transcription factor. Hence the present study highlights prematurity-induced reduction in PV+ neurons in human infants and reversal in their population by estrogen replacement in preterm rabbits. Because preterm birth drops plasma estrogen level 100-fold, estrogen replacement in extremely preterm infants might improve their developmental outcome and minimize neurobehavioral disorders.

G-1 exhibit antidepressant effect, increase of hippocampal ERs expression and improve hippocampal redox status in aged female rats

Postmenopausal depression has been shown to be related to the reduction of ovarian hormones produced as a woman transitions from a menopausal to a post-menopausal stage. What remains to be known is which type of estrogen receptor plays a key role in estrogen neuroprotection, a process that may be mediated by potentiating brain mitochondrial function and inhibiting mitochondria-associated apoptosis. In order to better imitate the condition of postmenopause, we conducted our research on aged female rats. Plasma estrogen levels declined significantly in ovariectomized rats and 16-month-old female rats, while anxiety and depression-like behavior increase. Moreover, ERα, ERβ, GPER, Bcl2 and UCP2 expression decreased significantly in hippocampus in female rats following ovariectomy. In our study, the anxiety and depression-like behavior in aged female rats were significantly relieved after the treatment of G-1, the GPER agonist. Furthermore, G-1 could reverse the reduction of ERα, ERβ, GPER, Bcl2 and UCP2 expression within the hippocampus. Mitochondrial JC-1 staining indicated that mitochondrial membrane potential increased after G-1 treatment. In addition, total antioxidant capacity (TAC) and superoxide dismutase activity (SOD) were found to be elevated in aged female rats following G-1 treatment. Taken together, estrogen receptors, especially GPER, may activate anti-apoptotic signaling and accelerate mitochondrial function. Therefore, GPER could be the potential therapeutic target for estrogen deficiency-related affective disorders.

Estrogen relaxes gastric muscle cells via a nitric oxide- and cyclic guanosine monophosphate-dependent mechanism: A sex-associated differential effect.

Various gastrointestinal (GI) disorders have a higher prevalence in women than in men. In addition, estrogen has been demonstrated to have an inhibitory effect on the contractility of GI smooth muscle. Although increased plasma estrogen levels have been implicated in GI disorders, the role of gastric estrogen receptor (ER) in these sex-specific differences remains to be fully elucidated. The present study was designed to investigate the sex-associated differences in the expression of the two ER isoforms, ERα and ERβ, and the effect of estrogen on gastric muscle contraction via the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway. Experiments were performed on single gastric smooth muscle cells (GSMCs) isolated from male and female Sprague Dawley rats. The effect of acetylcholine (ACh), a muscarinic agonist, on the contraction of GSMCs was measured via scanning micrometry in the presence or absence of 1 µM 17β-estradiol (E2), an agonist to the majority of ERs, 1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT), an ERα agonist, or diarylpropionitrile (DPN), an ERβ agonist. The protein expression levels of ER subtypes in GSMCs were measured using a specifically designed ELISA. GSMCs from female rats had a higher expression of ERα and ERβ protein compared with GSMCs from males. ACh induced less contraction in female that in male GSMCs. Pre-treatment of GSMCs with E2 reduced the contraction of GSMCs from both sexes, but to a greater extent in those from females. PPT and DPN inhibited ACh-induced contraction in GSMCs from females. Furthermore, E2 increased NO and cGMP levels in GSMCs from males and females; however, higher levels were measured in females. Of note, pre-incubation of female GSMCs with Nω-nitro-L-arginine, a NO synthase inhibitor, or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a guanylyl cyclase inhibitor, reduced the inhibitory effect of estrogen on GSMC contraction. In conclusion, estrogen relaxes GSMCs via an NO/cGMP-dependent mechanism, and the reduced contraction in GSMCs from females by estrogen may be associated with the sex-associated increased expression of ERα and ERβ, and greater production of NO and cGMP, compared with that in GSMCs from males.

Dietary fish oil replacement by soybean oil: Effect on plasma vitellogenin, sex steroids and ovarian steroidogenesis in Chinese strip-necked turtles (Mauremys sinensis )

In order to investigate the effects of dietary fish oil replacement, the turtles (Mauremys sinensis) were fed four experimental diets for 10 months: FO (100% fish oil), FSO (70% fish oil and 30% soybean oil), SFO (30% fish oil and 70% soybean oil) and SO (100% soybean oil), sampled at pre-vitellogenesis, vitellogenesis and post-vitellogenesis. The results showed that plasma gonadotropin-releasing hormone (GnRH) levels were the highest at pre-vitellogenesis, which promoted the secretion of gonadotropin and sex steroids. Therefore, plasma luteinizing hormone (LH) and estrogen (E2) levels were significantly increased at post-vitellogenesis (p < 0.05), while follicle-stimulating hormone (FSH) levels increased at vitellogenesis (p < 0.05). The FO and FSO groups had significantly higher GnRH and E2 levels than the other two groups (p < 0.05). In addition, plasma vitellogenin (Vtg) levels significantly increased at vitellogenesis and post-vitellogenesis (p < 0.05), which were significantly higher in the groups of FO and FSO than SO (p < 0.05). Moreover, the expression levels of hepatic estrogen receptor α (Erα) mRNA were significantly increased at vitellogenesis and post-vitellogenesis while ovarian Cyp19α1α mRNA were significantly increased at post-vitellogenesis (p < 0.05), and both were the lowest in SO. Taken together, the replacement of fish oil with 66.7% soybean oil is feasible.

Prenatal alcohol exposure increases the susceptibility to develop aggressive prolactinomas in the pituitary gland

Excess alcohol use is known to promote development of aggressive tumors in various tissues in human patients, but the cause of alcohol promotion of tumor aggressiveness is not clearly understood. We used an animals model of fetal alcohol exposure that is known to promote tumor development and determined if alcohol programs the pituitary to acquire aggressive prolactin-secreting tumors. Our results show that pituitaries of fetal alcohol-exposed rats produced increased levels of intra-pituitary aromatase protein and plasma estrogen, enhanced pituitary tissue growth, and upon estrogen challenge developed prolactin-secreting tumors (prolactinomas) that were hemorrhagic and often penetrated into the surrounding tissue. Pituitary tumors of fetal alcohol-exposed rats produced higher levels of hemorrhage-associated genes and proteins and multipotency genes and proteins. Cells of pituitary tumor of fetal alcohol exposed rat grew into tumor spheres in ultra-low attachment plate, expressed multipotency genes, formed an increased number of colonies, showed enhanced cell migration, and induced solid tumors following inoculation in immunodeficient mice. These data suggest that fetal alcohol exposure programs the pituitary to develop aggressive prolactinoma after estrogen treatment possibly due to increase in stem cell niche within the tumor microenvironment.