Plasma Estradiol Concentrations Research Articles

Evaluation of molt induction using cassava meal varying the length of feeding period in older (90 week) laying hens.

Physiological changes during molt and postmolt egg production variables were compared among hens induced to molt by using cassava meal varying the length of the feeding period. Hens were randomly assigned to 3 treatments of 72 birds each: 1) molted by full feeding with cassava meal for 4 wk (CAS4); 2) molted by full feeding with cassava meal for 5 wk (CAS5); and 3) molted by full feeding with cassava meal for 6 wk (CAS6). All groups were fed a pullet developer diet for 2 wk following treatment. During the molt period, the birds were exposed to an 8L:16D photoperiod and had access to drinking water at all times. Thereafter, all hens were fed a layer diet (17.71% CP), and exposed to a 16L:8D photoperiod, and production performance was measured for 16 wk. The molt treatments resulted in total cessation of egg production in all treatments within 2 wk following feeding of the molt diet. BW loss of birds in the CAS6 treatment was approximately 41.81%, which was significantly higher (P < 0.05) than those in the CAS5 (37.63%) and CAS4 (31.89%) treatments. The CAS5 and CAS6 hens had significantly lower (P < 0.05) ovarian and oviducal weights than the CAS4 hens. No consistent differences were observed for concentrations of plasma estradiol and progesterone, bone quality, or mortality among the treatments. Postmolt feed consumption, egg weight, and mortality were not different (P > 0.05) as a result of molt induction method. However, the CAS4 hens had significantly higher (P < 0.05) cumulative egg production and lower feed conversion ratio than hens in the CAS6 treatment. Significant differences were found among treatments for Haugh units and shell thickness in some periods of the postmolt. It was concluded that cassava meal could be used to induce molt in laying hens effectively, feeding the molt diet for 4 wk produced optimum body weight loss and postmolt performance.

Effects of Song Experience and Song Quality on Immediate Early Gene Expression in Female Canaries (Serinus canaria).

Female songbirds are thought to make mate choices based on aspects of male song quality. Male canaries (Serinus canaria) produce songs with "special" syllables that have been shown to be highly salient to female listeners - eliciting high rates of sexual displays and enhanced immediate early gene (IEG) expression. Immunohistochemistry for the IEG ZENK was used to examine the effects of experience with these syllables on activity in the caudal mesopallium (CMM) and nidocaudal mesopallium (NCM), two auditory areas important in processing conspecific song. Photostimulated female canaries were housed in sound attenuated chambers and played pseudosongs containing either three special syllables or three non-special syllables, an intro, and an outro sequence. Females that heard special syllable pseudosongs exhibited higher ZENK expression in CMM. To assess the effects of experience, photostimulated females were pair housed and exposed to playback of song with or without special syllables for 14days. After transfer to individual housing, birds were played one of the aforementioned stimuli or silence. ZENK expression in CMM and NCM was equivalent for song with and without special syllables, but significantly lower for silence. Females who experienced song with special syllables had lower plasma estradiol concentrations after final song playback. This study indicates that CMM exhibits an IEG response bias to special syllables in limited acoustic contexts, but not in full song, which may contain additional biologically relevant information. Furthermore, estradiol concentrations may mediate changes in song responses, serving as a mechanism for modulating mate choice in differing song environments.

Influence of social stability on the sex determination process in false clown anemonefish (Amphiprion ocellaris)

ABSTRACTTo evaluate the involvement of plasma cortisol in sex determination in hermaphrodite protandrous sex-changing fish, sexually immature false clown anemonefish (Amphiprion ocellaris) were kept in groups of 3 individuals for 360 days. Observations of time-course changes of diurnal behaviour and plasma concentrations of cortisol, oestradiol, and 11-ketotestosterone were evaluated. The social hierarchy of the experimental groups was assumed to become stable during the middle period of the experiment, but unstable at the beginning and at the end according to the increase or decrease in the frequencies of agonistic behaviours. The plasma concentration of cortisol increased as the social hierarchy became unstable and oestradiol showed the opposite trend to cortisol. These results suggest that in protandrous anemonefish sex determination induced by social interaction is mediated by cortisol. The stability of the social hierarchy is considered to be very important for the sex determination process.

OR18-2 Higher Plasma Estradiol Concentration Is Independently Associated with Lower Biological Age, Assessed as Leucocyte Telomere Length, in Older Men

Telomeres are essential DNA-protein complexes comprising TTAGGG repeats binding specific proteins, which protect the physical ends of chromosomes from fusion and degradation. Attrition of telomeres results in cellular senescence. Leucocyte telomere length (LTL) reflects lengths of telomeres in various tissues, and shorter LTL is a marker of advancing biological age. Previous work has associated bioactive metabolites of T, dihydrotestosterone (DHT) and estradiol (E2) with LTL in a population of predominantly middle-aged men [1]. However, the relationship of these hormones to biological age in older men was unclear. We aimed to clarify associations of sex hormones with LTL in a cohort of 2,913 community-dwelling men aged 70-89 years. Early morning blood samples were assayed for T, DHT and E2 using mass spectrometry, and for sex hormone-binding globulin (SHBG) using immunoassay. LTL was measured using a multiplex quantitative PCR method and expressed as the amount of telomeric DNA relative to beta-globin, a single copy control gene (T/S ratio). Cross-sectional analyses utilised multivariable linear regression. Mean (±SD) age was 76.7±3.2 years. The average difference per decade of age was T -0.46 nmol/L, DHT -0.11 nmol/L, E2 -7.5 pmol/L, SHBG +10.2 nmol/L, and LTL (T/S ratio) -0.065. E2 correlated with T/S ratio (r=0.038, p=0.039). After excluding highest and lowest 1% of values, the correlation between E2 and T/S ratio was largely unchanged (r=0.039, p=0.037). SHBG was inversely correlated with T/S ratio (r=-0.053, p=0.004), also unchanged in the trimmed analysis (r=-0.055, p=0.004.) After adjusting for age, BMI, cardiovascular disease, diabetes, alcohol, smoking, physical activity, lipids and hypertension, E2 remained associated with T/S ratio (per 1 SD increase E2: coefficient 0.011, p=0.043). When E2 and SHBG were simultaneously included in the multivariate model, E2 remained positively associated with T/S ratio (coefficient 0.014, p=0.014) and SHBG inversely associated (coefficient -0.013, p=0.037). The magnitude of increase in T/S ratio associated with a 1 SD higher plasma E2 concentration was comparable with having a BMI 3.6 kg/m2 lower, and two thirds that associated with being 3.6 years younger. T, DHT and LH were not associated with LTL in multivariate analyses. To conclude, in older men, neither T nor DHT are associated with LTL while E2 is independently associated with LTL and SHBG is inversely associated. These findings associate activity of the gonadal axis with lower biological age in older men. However, causality cannot be inferred from an observational, cross-sectional study, thus additional research is necessary to determine whether sex hormone exposure modulates male biological ageing. Reference: [1] Yeap BB, et al. J Clin Endocrinol Metab 2016; 101: 1299-1306.

Plasma concentrations of dimeric inhibin and oestradiol in heifers undergoing superovulation with eCG or FSH

Plasma concentrations of dimeric inhibin and oestradiol in heifers undergoing superovulation with eCG or FSH

Plasma hormone concentrations associated with early embryo mortality in heifers

Results of a detailed study involving 18 pregnant, 17 cyclic and 12 inseminated but non-pregnant Holstein heifers indicated the following. (1) Jugular plasma progesterone concentrations were higher (P less than 0.05) in pregnant than in cyclic or in inseminated--non-pregnant animals from Days 10 through 18. (2) Jugular plasma progesterone concentrations of inseminated--non-pregnant animals could be related to heifers in which (a) fertilization may not have occurred (N = 5); (b) embryonic death may have occurred between Days 6 and 9 (N = 5); and (c) embryo mortality may have occurred shortly before Day 18 (N = 2). (3) Jugular plasma oestradiol concentrations were higher (P less than 0.05) in pregnant than in cyclic animals between Days 10 and 18; the oestrogen values of the inseminated--non-pregnant animals resembled those of the pregnant animals. (4) The steroid-synthesizing capabilities of incubated luteal tissues from inseminated--non-pregnant heifers more closely resembled those of tissues from pregnant animals than those of cyclic animals. (5) At Day 18 PGF concentrations in endometrial and luteal tissues and ovarian arterial plasma did not differ among the 3 groups. (6) PGF and progesterone concentrations of luteal tissues were negatively correlated (r = -0.77, P less than 0.05) in cyclic animals and positively correlated (r = 0.73, P less than 0.05) in pregnant animals, implying a luteotrophic effect of PGF in pregnant animals. These results suggested a luteotrophic effect of the embryo, beginning as early as Day 10 of pregnancy, and the results of further experiments suggested that (i) homogenates and extracts of Day 18 bovine embryos contain one or more substances capable of stimulating progesterone synthesis in dispersed bovine luteal cell preparations; (ii) the luteotrophic activity was proportional to the protein contents of the embryo homogenates; and (iii) the luteotrophic activity was heat labile and was removed from homogenates by dialysis, indicating a structure of one or more relatively small molecules.

Sex Difference and Hormones in the Regulation of Vasopressin Secretion during Dilutional Hyponatremia

Dilutional hyponatremia due to elevated arginine vasopressin (AVP) secretion increases mortality in patients with liver failure. No previous studies have addressed sex difference in dilutional hyponatremia in animal models of liver failure. The aim of this study is to investigate sex difference in dilutional hyponatremia and the effect of ovarian hormones in AVP secretion. We have used chronic bile duct ligated (BDL) rats, a model of dilutional hyponatremia associated with liver failure.Adult male Sprague Dawley rats, female Sprague Dawley rats and ovariectomized (OVX) female rats were used. After two weeks, the rats had BDL or sham ligation surgery. Four weeks later, the brains were processed for immunohistochemistry analysis of FosB and AVP expression. Blood samples were collected to measure plasma osmolality, hematocrit, circulating estradiol and copeptin concentration. Copeptin was used as biomarker for plasma AVP. Liver weight, body weight, and fluid accumulation were recorded to verify if the rats developed liver failure and ascites. Data were analyzed by one ANOVA with Bonferroni post hoc comparisons.All the BDL rats had significant increase in liver to body weight ratio compared to sham rats indicating liver failure and ascites with bile duct ligation. Male BDL rats had hyponatremia along with significant increases in plasma copeptin and FosB expression in Supraoptic AVP neurons compared to male shams (all p&lt;0.05; 5–7). Unlike male BDL rats, the female BDL rats did not become hyponatremia and did not had increases Supraoptic AVP neuron activation and copeptin secretion compared to female sham.Ovariectomy significantly decreased plasma estradiol concentration in sham rats compared to intact female sham (p&lt; 0.05; 6–10). However, circulating estradiol concentration was significantly elevated in ovariectomized BDL (OVX BDL) rats compared to the ovariectomized sham (OVX sham) and female sham rats (p&lt;0.05; 6–10). To identify the source of estradiol contributing to the observed increase in OVX BDL rats, adrenal glands were collected at the end of protocol. Adrenal gland steroids were extracted to measure estradiol and its precursors, testosterone and DHEA concentration.The OVX BDL rats had significantly increased adrenal estradiol along with significant decrease in adrenal testosterone and DHEA compared to OVX sham rats (all p&lt; 0.05; 6–7). Plasma osmolality, hematocrit and copeptin concentration were not different between OVX BDL and OVX sham rats. Our results show that unlike male BDL rats, female BDL rats did not develop hyponatremia, supraoptic AVP neuron activation, or increased copeptin secretion compared to sham ligated females. Female OVX BDL rats did not become hyponatremia or increased copeptin secretion compared to female OVX sham rats. It is possible that the increase in adrenal estradiol compensated for the lack of ovarian estrogens in OVX BDL rats. Additional experiments will be required to determine the effects of estrogen in this model.Support or Funding InformationSupported by R01 HL119458 and 18PRE34060035This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Intensity dependent disruptive effects of light at night on activation of the HPG axis of tree sparrows (Passer montanus)

Artificial light at night (ALAN) has become increasingly recognized as a disruptor of the reproductive endocrine process and behavior of wild birds. However, there is no evidence that ALAN directly disrupt the hypothalamus-pituitary-gonadal (HPG) axis, and no information on the effects of different ALAN intensities on birds. We experimentally tested whether ALAN affects reproductive endocrine activation in the HPG axis of birds, and whether this effect is related to the intensity of ALAN, in wild tree sparrows (Passer montanus). Forty-eight adult female birds were randomly assigned to four groups. They were first exposed to a short light photoperiod (8 h light and 16 h dark per day) for 20 days, then exposed to a long light photoperiod (16 h light and 8 h dark per day) to initiate the reproductive endocrine process. During these two kinds of photoperiod treatments, the four groups of birds were exposed to 0, 85, 150, and 300 lux light in the dark phase (night) respectively. The expression of the reproductive endocrine activation related TSH-β, Dio2 and GnRH-I gene was significantly higher in birds exposed to 85 lux light at night, and significantly lower in birds exposed to 150 and 300 lux, relative to the 0 lux control. The birds exposed to 85 lux had higher peak values of plasma LH and estradiol concentration and reached the peak earlier than birds exposed to 0, 150, or 300 lux did. The lower gene expression of birds exposed to 150 and 300 lux reduced their peak LH and estradiol values, but did not delay the timing of these peaks compared to the control group. These results reveal that low intensity ALAN accelerates the activation of the reproductive endocrine process in the HPG axis, whereas high intensity ALAN retards it.

Withdrawal of plasma estradiol is associated with increased anxiety reported by women in the first 12 hours after delivery

The aim of this study was to verify if the fall of plasma concentrations of steroid hormones in the first 12 h postpartum would be associated with changes in the same period in the emotional state of healthy women. Subjective and hormonal data were collected from 14 women (28.5 ± 7.1 years old) at zero (only hormones), 1, 2, 6 and 12 h after delivery. Subjective measures were taken using the Visual Analogue Mood Scale (VAMS), which consists of four factors (anxiety, sedation, discomfort, and cognitive impairment). Cortisol was measured by radioimmunoassay and estradiol and progesterone by chemiluminescence immunoassay. Women reported a significant increase in anxiety (relative increase: 43.8%±77.6) and discomfort (125.9%±218.5) within the 12 h postpartum. There were also significant decreases in the plasma concentration of estradiol (relative decrease: 96.5%±3.1), progesterone (78.1%±8.7) and cortisol (71.7%±18.0). The relative decrease in estradiol concentrations was significantly correlated with the relative increase in anxiety. No significant associations between progesterone and cortisol concentrations and subjective measures were observed. Changes of estradiol but not of progesterone and cortisol concentrations were associated with changes in the reported emotional state of healthy women in the immediate postpartum period. The role of this association as a predictor of mood disorders in the postpartum period should be explored in further studies.

Spermatogenesis and steroid hormone profile in puberty of laboratory-reared common snook (Centropomus undecimalis)

The common snook, Centropomus undecimalis, is a protandrous hermaphrodite and considered an emerging species for intensive fish culture on the American continent. This study describes the onset of puberty in this species, correlating growth parameters, gonadal morphology (histology) and plasma concentrations of testosterone (T), 11-ketotestosterone (11-KT) and estradiol (E2) under two rearing conditions. Two experimental groups with 500 fish each were conducted until fish reached puberty, the first in a net cage (28 m3) inside an earthen estuarine pond (Exp. 1) and the second in a thermal-controlled tank (9.6 m3) in a recirculation aquaculture system (Exp. 2). The fish in Exp.1 initiated puberty in the second year (305.35 ± 91.78 g and 34.31 ± 3.48 cm). The fish in Exp. 2 initiated puberty in the first year (303.05 ± 40.38 g and 35.11 ± 1.34 cm), influenced mainly by the higher somatic growth. Only the fish in Exp. 1 reached the most advanced stage of spermatogenesis with the release of semen, probably due to the maturation of the reproductive system. Variations in gonadal steroids (T, 11-KT and E2) regulated the progression of spermatogenesis during the reproductive season, and these variations demonstrated a relevant role in the development of the testes. Plasma levels of T and E2 were higher (P < .05) in Exp. 2, indicating influence of the culture environment. However, plasma concentrations of 11-KT were not influenced by the environment, suggesting an important role of this androgen in the regulation of spermatogenesis. The results of this study show that in a controlled environment common snook can initiate puberty with one year old, which normally occurs in two-year-old in an environment with seasonal variations. This indicates a plasticity in the onset of puberty in the common snook, mostly related to body size than age.

Plasma progesterone, estradiol, and unconjugated estriol concentrations in twin pregnancies: Relation with cervical length and preterm delivery.

The aim of this study was to examine the association between plasma hormone concentrations, cervical length, and preterm delivery in twin pregnancies, including the effect of progesterone treatment. This study included 191 women pregnant with twins from a randomized placebo-controlled trial. A baseline blood sample was collected at 18-24weeks before treatment with vaginal progesterone (n=95) or placebo pessaries (n=96), and 167 (87.4%) women had a second sample collected after 4-8weeks of treatment. At baseline, 155 (81.2%) women had their cervical length measured. Progesterone, estradiol, and unconjugated estriol concentration was measured, and the association between hormone concentrations, cervical length, and gestational age at delivery was examined. Hormone concentrations were compared in the placebo and progesterone group. Statistical analysis included Spearman's rho, Mann-Whitney U test, Cuzick's test for trends, and linear regression analyses. A short cervical length was associated with preterm delivery. Cervical length and hormone concentrations were not associated (Spearman's rho; progesterone -.05, estradiol .04, estriol .08). Decreasing gestational age at delivery was associated with higher progesterone and estradiol concentrations at baseline (P trend; progesterone 0.04, estradiol 0.02) but not in the second sample or in the weekly change between samples. Progesterone treatment did not increase the progesterone concentration. Plasma concentrations of progesterone, estradiol, and unconjugated estriol at 18-24weeks are not associated with cervical length or preterm delivery in twin pregnancies. Vaginal progesterone treatment does not increase the circulating progesterone concentration in twin pregnancies. Cervical length, but not hormone concentration, is predictive of preterm delivery in twin gestations.

Endocrine and molecular regulation mechanisms of the reproductive system of Hungarian White geese investigated under two artificial photoperiodic programs

Hungarian White geese are regarded as good producers of meat, eggs, and feathers, but specific lighting schedules are required to improve their egg-laying performance. This study reveals the neuroendocrine regulatory mechanisms that govern the reproductive activities and egg-laying performances of Hungarian White geese. The results indicated that increasing the daily photoperiod from a short 8 h period to either 11 h or 14 h initiated reproduction. Egg-laying rates increased faster in the 14 h group, peaking (48.2%) on day 33 as compared to the peak (52.67%) reached on day 53 in the 11 h group. Changes to the plasma estradiol and progesterone concentrations produced similar patterns in the two groups. In the hypothalamus, OPN5, Dio2, c-Fos, and GnRH-I expression levels showed similar sequential increases and decreases. Changes in GnIH and VIP expression levels were the opposite to those of GnRH-I, but the levels peaked earlier under the 14 h photoperiod conditions. Pituitary LH beta and FSH beta expression levels increased at slower rates but remained significantly higher in the 11 h group than in the 14 h group. However, pituitary PRL expression increased considerably earlier and was higher in 14 h geese than in 11 h geese, which was opposite to the observed egg-laying rate patterns. An increase from a short to a relatively long photoperiod (11 h) regulated the neuroendocrine system and led to reproductive activities being sustained for a longer period, which resulted in high egg-laying performances.

Environmental Exposure to Endocrine Disruptor of Bisphenol A and Semen Quality of Men

Background: The reproductive health disorders in men are one of the urgent problems of international medicine. The prevalence of idiopathic male infertility has the highest rate. Oxidative stress, genetic factor, and endocrine disruptors are considered to be the most probable causes for the idiopathic male infertility. In this regard, studying the effect of endocrine disruptors, in particular bisphenol A on male reproductive health, becomes actual and relevant. Aims: The aim of the study was to reveal the relationship between the concentration level of bisphenol A (BPA) in seminal fluid and semen quality in men with normo- or pathozoospermia, as well as between the concentration level of bisphenol A and the level of total testosterone and estradiol in plasma. Materials and methods: 53 samples of seminal fluid of men with normo- or pathoospermia were studied. In seminal fluid the concentration of bisphenol A was determined by gas chromatography with mass spectrometry (GC-MS). The spermiological analysis was performed according to the WHO recommendations (2010) including the evaluation of sperm count/concentration, motility and morphology, and DNA fragmentation index. In addition, the concentration of total testosterone and estradiol in plasma was determined. The results were statistically processed using the Mann–Whitney U test, the correlation analysis, the paired regression method, and the ROC curves to determine the cut-off point for BPA in the seminal fluid. The results were considered statistically significant at p0.05. Results: In 100% of the ejaculate samples BPA with a median concentration of 0.15 (0.06–0.31) ng/ml was detected. Using the Spearman rank correlation coefficient, statistically significant correlations between the concentration of BPA and the total count (r=-0.330, p=0.016), concentration (r=-0.309; p=0.024), the proportion of progressively motile spermatozoa (r=-0.575; p=0.001), the proportion of spermatozoa with normal morphology (r=-0.397, p=0.003), the degree of sperm DNA fragmentation (r=0.349, p=0.025), and the concentration of total testosterone (r =-0.616; p0.001) were registered. A statistically significant inverse linear relationship (r=-0.406, p=0.003) and (r =-0.364, p=0.048) was determined by a paired linear regression between the BPA concentration in the seminal fluid and the proportion of progressively motile spermatozoa, and the total testosterone level respectively. To assess the risk of pathozoospermia, the threshold value of seminal BPA concentration was determined using the analysis of ROC-curves; the cut-off point was 0.1025 ng/ml. Conclusions: BPA in the seminal fluid influences negatively on the quality of the sperm and suppress the level of total testosterone in plasma.

Effects of glucocorticoid on the eye development in guinea pigs

Glucocorticoid (GC) has been widely used in clinic. However, the effect of GC on normal and myopic development of eyes is still unknown. In this study, 3-week-old guinea pigs were randomly divided into four groups: No-Lens (control), GC+No-Lens, negative lens-induced myopia (LIM), and GC+LIM. To induce myopia, right eyes were covered with a −10 D lens in GC+LIM and LIM groups. GC+No-Lens and GC+LIM groups received intraperitoneal injections of hydrocortisone (10 mg/kg) once daily for 2 weeks, and then received intragastric hydrocortisone (32.5 mg/kg) every other day for the next 4 weeks, while No-Lens (control) and LIM groups were injected intraperitoneally with saline for 2 weeks, and then given saline by intragastric administertion for the next 4 weeks. Several parameters were assessed: ocular axial length and refractive error, sclera thickness, matrix metalloprotein-2 (MMP-2) and tissue inhibitor metalloprotease-2 (TIMP-2) expressions and localization of the posterior sclera, plasma concentrations of free triiodothyronine (FT3), free thyroxine (FT4), testosterone (T), and oestradiol (E2). Results indicated that: (1) in normal eye development, hydrocortisone could inhibit both the axial elongation and the myopic shift; whereas (2) in LIM eye development, hydrocortisone (a) enhanced the axial elongation, myopic shift and sclera thinning; (b) enhanced the MMP-2 expression and decreased TIMP-2 expression, and (c) elevated the plasma concentration of E2 but decreased the levels of FT3, FT4, and T. In conclusion, glucocorticoid may influence both normal and LIM eye development. The balance of the hormones is fundamental for the eye development.

Effects of short-term intravaginal progestagens on the onset and features of estrus, preovulatory LH surge and ovulation in sheep

In the present study, there was a comparison among classical long-term progestagen (fluorogestone acetate) protocols for synchronization of estrus and ovulation (14 days; group FGA14, n = 9 ewes) and short-term protocols based on 7 days of progestagen treatment plus a dose of prostaglandin F2α at either insertion (PG-FGA7, n = 11) or removal (FGA7-PG, n = 12). There were no significant differences in the ovulation rate and progesterone secretion among treatments. The FGA7-PG group, however, had a similar percentage of ewes expressing estrous behavior than the group FGA14 (90.9 and 100%, respectively, with a trend for a lesser percentage in the PG-FGA7 group, 63.6%) and about 90% of the ewes in the FGA7-PG group had the preovulatory surge release of LH 8 h after the onset of estrous behavior. These features may be related to a greater number of preovulatory follicles during growing phases (P < 0.05) and a greater plasma estradiol concentration (P < 0.05) in this group than in the classical 14-day group, which suggest these are more functional preovulatory follicles. In conclusion, therefore, the use of the FGA7-PG treatment may favor efficiency of progestagen-based protocols for reproductive management.

Effect of seasonality on testicular blood flow as determined by color Doppler ultrasonography and hormonal profiles in Shiba goats

The objectives of this study were to determine if there is a seasonal pattern of testicular blood flow in male Shiba goats, and ascertaining whether or not there is a relationship among changes in testicular hemodynamics and circulating testosterone (T) and estradiol (E2). Twelve sexually mature male Shiba goats (Capra hircus), aged 19.5 ± 2.5 months were used in this study. Monitoring of the changes in testicular blood flow was performed once a week for 1 year, using color spectral Doppler ultrasonography. Plasma concentrations of testosterone (T) and estradiol (E2) were determined by radioimmunoassay. Among the four seasons, the greatest increases (P ≤ 0. 001) in the values for the resistive index (RI) and pulsatility index (PI) of the testicular artery were recorded in the summer. Also, PI and RI values recorded in spring were greater than those recorded in autumn, while for winter there were the least values for these indices. Likewise, concentrations of T and E2 showed seasonal changes. Concentrations of T and E2 were greater during the autumn and winter compared to those in spring and summer. Interestingly, E2 concentrations were negatively associated with Doppler indices of the testicular artery. In conclusion, although Shiba goats are considered to be non-seasonal breeding animals, there were distinct seasonal patterns of testicular blood flow as measured by color Doppler ultrasonography, especially in Doppler indices. These changes were coincident with the changes in the circulating E2 and may be attributable to the seasonal changes in ambient temperature or daylight length.

Maintenance of bone mass despite estrogen depletion in female common marmoset monkeys (Callithrix jacchus).

Estrogen depletion leads to bone loss in almost all mammals with frequent regular ovarian cycles. However, subordinate adult female common marmosets (Callithrix jacchus) undergo socially induced anovulation and hypoestrogenism without clinically apparent adverse skeletal consequences. Thus, we speculated that this non human primate might have evolved a mechanism to avoid estrogen-depletion bone loss. To test this possibility, we performed three experiments in which lumbar-spine (L5-L6) bone mineral content (BMC) and density (BMD) were assessed using dual-energy X-ray absorptiometry: (i) cross-sectionally in 13 long-term ovariectomized animals and 12 age- and weight-matched controls undergoing ovulatory cycles; (ii) longitudinally in 12 animals prior to, 3-4 and 6-7 months following ovariectomy (ovx), and six controls; and (iii) cross-sectionally in nine anovulatory subordinate and nine dominant females. In Experiments 1 and 3, plasma estradiol and estrone concentrations were measured and uterine dimensions were obtained by ultrasound in a subset of animals as a marker of functional estrogen depletion. Estrogen levels, uterine trans-fundus width, and uterine dorso-ventral diameter were lower in ovariectomized and subordinate females than in those undergoing ovulatory cycles. However, no differences were found in L5-L6 BMC or BMD. These results indicate that estrogen depletion, whether surgically or socially induced, is not associated with lower bone mass in female common marmosets. Thus, this species may possess unique adaptations to avoid bone loss associated with estrogen depletion.

Endocrine disruption in Chinese rare minnow (Gobiocypris rarus) after long-term exposure to low environmental concentrations of progestin megestrol acetate

Synthetic progestins are widely used pharmaceutical agents that have become common contaminants in the aquatic environment. The potential adverse effects of long-term exposure on aquatic wildlife, however, are not fully understood. The aim of this study was to investigate the endocrine disruption in Chinese rare minnow (Gobiocypris rarus) in response to megestrol acetate (MTA) exposure. Newly-hatched Chinese rare minnow larvae were exposed to MTA at a nominal concentration of either 1 ng/L (detected concentrations ranged from 0.18 to 0.93 ng/L) or 10 ng/L (detected concentrations ranged from 4.27 to 9.64 ng/L) for 6 months and the effects on growth, sex steroid hormones, gonadal histology, and steroidogenic genes expression were determined. After 6 months of exposure to a nominal concentration of 10 ng/L MTA, the body weight and condition factors were significantly increased in fish of both sexes. Exposure to a nominal concentration of 10 ng/L MTA significantly reduced plasma concentrations of estradiol and 11-ketotestosterone in female fish while also reducing testosterone and 11-ketotestosterone in male fish. Gonad histology revealed significantly reduced proportions of vitellogenic oocytes in female fish exposed to a nominal concentration of 10 ng/L MTA and induction of atretic follicles in female fish exposed to both nominal concentrations of MTA. The expression of cyp19a1a and cyp17a1 in the gonads was up-regulated in the ovaries while down-regulated in the testes. Our results indicate that MTA can induce endocrine disruption in Chinese rare minnow at the low concentrations found in contaminated environments. This indicates a potentially high ecological risk from MTA to fish populations in MTA-contaminated aquatic environments in China and may also in other regions.

Sex steroids and risk of differentiated thyroid carcinoma: Results from the EPIC study

Introduction The incidence of thyroid carcinomas has been rapidly increasing over the last 20–30 years in many Westernized countries. Large part of the increase is due to diagnostic improvements, however other changes may be involved. The only well-established risk factors for differentiated thyroid carcinomas (TC) (the most common forms of TC) are history of benign thyroid disease, notably goiter and benign nodules, and exposure to ionizing radiations (especially during childhood). However, recent studies have shown consistent evidence that body mass, including height and weight, are also positively associated with differentiated TC risk. However, mechanisms that may explain this association are currently not known but can include sex hormones. We therefore investigated the role of sex steroids and sex hormones binding globulin (SHBG) in the etiology of differentiated thyroid cancer in a case-control study nested within the large European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Methods Within EPIC, during follow-up, we identified 329 primary incident cases of differentiated thyroid carcinoma (133 in pre-menopausal women, 118 in postmenopausal women, and 78 in men) among subjects who participated in the study and gave a blood sample at blood collection. To these cases, 710 controls, who did not develop any cancers, apart from non-melanoma skin cancer, at the time of the diagnosis of the case, were matched on study recruitment center, sex, age, date, time, fasting status at blood collection, duration of follow-up, and, in women, menopausal status and phase of the menstrual cycle. Women taking exogenous hormones at blood donation were excluded. Plasma concentrations of testosterone (T), androstenedione (D4), dehydroepiandrosterone (DHEA), estradiol, estrone and progesterone (in pre-menopausal women only) were performed by a highly sensitive high-resolution liquid chromatography/mass spectrometry (LC-HSMS/MS) method. SHBG concentrations were measured by a validated immunoassay. Odds ratios (ORs) of TC by levels of each biomarker were estimated using conditional logistic regression models adjusted for potential confounders (including height, waist circumference, physical activity, smoking status, alcohol consumption, education level, and for women, age at first full term pregnancy, number of full term pregnancies, and exogenous hormone use). Results In pre-menopausal women, controls had a lower BMI, a shorter waist circumference, and a higher alcohol intake than the cases (24.2 vs. 25.7 kg/m2 for BMI, 76.5 vs. 80.0 cm for waist, 3.2 vs. 1.8 g/day for alcohol intake, respectively). Preliminary conditional logistic regression analyses suggest positive associations of borderline statistical significance of differentiated thyroid cancer with the concentrations of T, D4 and DHEA in pre-menopausal women (ORT3vsT1: 1.83 (95% CI: 0.99–3.39) for T; 1.99 (95% CI: 1.02–3.87) for D4; 1.84 (95% CI: 0.95–3.56) for DHEA). No associations could be observed in postmenopausal women nor in men. No associations were found with estrogens or progesterone. Conclusions This study is the first prospective study conducted on sex steroids and differentiated TC risk and will provide insights on mechanisms relating overweight and obesity to TC risk. Our preliminary results suggest a possible positive association of differentiated TC risk with high androgen concentration in pre-menopausal women but no relationship with estrogens or progesterone.

Potential Biomarkers with Plasma Cortisol, Brain-derived Neurotrophic Factor and Nitrites in Patients with Acute Ischemic Stroke

Acute Ischemic Stroke (AIS) represents an economic challenge for health systems all over the globe. Changes of neuroactive steroids have been found in different neurological diseases. We have previously demonstrated that old patients with AIS show changes of plasma cortisol and estradiol concentrations, in that increased steroid levels are associated with a deterioration of neurological status and a worse cognitive decline. The present study assessed in patients with AIS if changes of behavior, Brain-Derived Neurotrophic Factor (BDNF) and Nitrites (NO-2) bear a relationship with the degree of hypercortisolism. We recruited patients hospitalized within the first 24 hours of AIS. Subjects were divided into two groups, each one composed of 40 control subjects and 40 AIS patients, including men and women. The neurological condition was assessed using the National Institute of Health Stroke Scale (NIHSS) and the cognitive status with the Montreal Cognitive Assessment (MoCA). The emotional status was evaluated using the Montgomery-Asberg Depression Rating Scale (MADRS), whereas the Modified Rankin Scale (MRS) was used to determine the functional condition. BDNF and NO-2 plasma levels were measured by ELISA and the Griess reaction method, respectively. We found that in AIS patients, increased plasma cortisol was negatively correlated with plasma BDNF and NO-2 levels, neurological condition, cognition, functional responses and emotional status, suggesting a relationship between the declines of clinical, behavioral and blood parameters with stress-induced cortisol elevation. Nitrites and BDNF may represent potential biomarkers for cortisol negative effects on the area of cerebral ischemia and penumbra, potentiating ischemic cell damage.