The effect of sex steroid hormones on the ecology of in vitro oral biofilms.

Sex steroid hormones (SSH) such as oestrogen, progesterone and testosterone are cholesterol derived molecules that regulate various physiological processes. They are present in both blood and saliva, where they come in contact with oral tissues and oral microorganisms. Several studies have confirmed the effect of these hormones on different periodontal-disease-associated bacteria, using single-species models. Bacteria can metabolize SSH, use them as alternative for vitamin K and also use them to induce the expression of virulence factors. However, it is still unclear what the effects of SSH are on the oral microbiome. In this study, we investigated the effects of four SSH on commensal in vitro oral biofilms. Saliva-derived oral biofilms were grown in Mc Bain medium without serum or menadione using the Amsterdam Active-Attachment model. After initial attachment in absence of SSH, the biofilms were grown in medium containing either oestradiol, oestriol, progesterone or testosterone at a 100-fold physiological concentration. Menadione or ethanol were included as positive control and negative control, respectively. After 12 days with daily medium refreshments, biofilm formation, biofilm red fluorescence and microbial composition were determined. The supernatants were tested for proteolytic activity using the Fluorescence Resonance Energy Transfer Analysis (FRET). No significant differences were found in biofilm formation, red fluorescence or microbial composition in any of the tested groups. Samples grown in presence of progesterone and oestradiol showed proteolytic activity comparable to biofilms supplemented with menadione. In contrast, testosterone and oestriol showed a decreased proteolytic activity compared to biofilms grown in presence of menadione. None of the tested SSH had large effects on the ecology of in vitro oral biofilms, therefore a direct translation of our results into in vivo effects is not possible. Future experiments should include other host factors such as oral tissues, immune cells and combinations of SSH as present in saliva, in order to have a more accurate picture of the phenomena taking place in both males and females.

Effect of acupuncture on the opening time of implantation window and endometrial receptivity in controlled ovarian hyperstimulation rats during peri-implantation period.

Purpose: To investigate the effect of acupuncture for improving the pregnancy rate of COH rats from the viewpoint of regulating the opening time of the implantation window and endometrial receptivity. Methods: Experimental rats were randomly divided into normal group (N), model group (M) and acupuncture group(A), and samples were collected on Day 4, 5 and 6 after mating. COH rats were treated with acupuncture at SP6, LR3, and ST36 once a day for 7 times. The pinopodes were observed under a scanning electron microscope. Serum estrogen and progesterone levels were measured via ELISA. The protein and mRNA levels of estrogen receptor (ER), progesterone receptor (PR), leukemia inhibitory factor (LIF), integrin ß3, vascular endothelial growth factor (VEGF), and fibroblast growth factor 2 (FGF-2) in the endometrium were evaluated via West-blot, immunohistochemistry, and PCR. Results: Compared with group N, the pregnancy rate of group M was significantly decreased (P<0.05), and the abnormal serum hormone levels and implantation window advancement were observed. Compared with group M, the pregnancy rate of group A was significantly increased (P<0.05), the supraphysiological serum progesterone levels were restored to normalcy (P<0.05), and the advanced implantation window was restored to a certain extent. Further, the abnormal ER, PR, LIF, integrin ß3, VEGF, and FGF-2 expression levels of the endometrium got recovered to varying degrees. Conclusion: Acupuncture may restore the estrogen and progesterone balance in COH rats and the forward shift of the implantation window to a certain extent, improving the endometrial receptivity and finally improving the pregnancy rate of COH rats.

Interaction between Pelvic Bone Mineral Density and Sex Steroid Hormone on the Risk of Urinary Incontinence from National Health and Nutrition Examination Survey 2013-2014.

INTRODUCTION: The correlation between sex hormone levels and pelvic bone mineral density in people with urinary incontinence (UI) has not been evaluated. This study explored the association between sex hormones, pelvic bone mineral density, and UI, and analyzed the association between pelvic bone mineral density-combined sex hormones and UI in women. METHOD: The data of the National Health and Nutrition Examination Survey (NHANES) 2013-2014 were used in this cross-sectional study. Women aged 20 years and older with complete sex steroid hormone and pelvic bone mineral density data were included. Outcomes were stress UI (SUI), urgency UI (UUI), and mixed UI (MUI). Sex steroid hormone included testosterone, estradiol, and sex hormone binding globulin (SHBG). Multivariate logistic regression analyses with the odds ratios (ORs) and 95% confidence intervals (CIs) were used. RESULTS: Of 2,442 women, 579 had SUI, 202 had UUI, and 344 had MUI. The estimated multiplicative interactions were significantly between testosterone and pelvic bone mineral density, between SHBG and pelvic bone mineral density on UI (p = 0.002, p = 0.003), MUI (p = 0.036, p < 0.001), and SUI (p = 0.008, p = 0.044), respectively. High pelvic bone mineral density was associated with UI (p = 0.022) and MUI (p = 0.028) in the age <45-year-old subgroup. Multiplicative interactions were between testosterone and pelvic bone mineral density on all types of UI in the age <45-year-old subgroup, on SUI in women who did not have vaginal deliveries, and on UI in women who had more than one-time vaginal delivery. CONCLUSION: Our study found negatively multiplicative interactions between testosterone, SHBG, and pelvic bone mineral density on UI, MUI, and SUI. Similar results were found in women aged <45 years old and in women who had more than one-time vaginal delivery. Clinicians may consider testosterone or SHBG supplementation and pelvic density enhancement in women with SUI, MUI, and low endogenous testosterone levels.

An UHPLC-MS/MS method for simultaneous determination of ten sex steroid hormones in ovariectomy-induced osteoporosis rat and its application in discovery of sex steroid hormones regulatory components of Xian-Ling-Gu-Bao capsule.

Sex steroid hormones could directly affect the bone metabolism by regulating cell physiological functions. In female, it inevitably causes the abnormal levels of sex steroid hormones at post-menopause in vivo. Ovariectomized rats and mice are classic animal models of osteoporosis to better understand the action mechanism of anti-osteoporosis drugs. However, it is not clear whether Xian-Ling-Gu-Bao capsule (XLGB), a kidney-tonifying traditional Chinese medicine prescription, treat osteoporosis via regulating multiple sex steroid hormones. In the present study, a reliable method involving ultra high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC/TQ-XS-MS) was developed for simultaneous quantitative analysis of ten sex steroid hormones (three estrogens, five androgens and two progestogens) in rat and mouse serum. The results of methodology were acceptable. The validated method was then successfully applied in the determination of the levels of sex steroid hormones in ovariectomy-induced osteoporosis rats, as well as drug (17ß-estradiol and XLGB) intervened rats. As a result, XLGB could not only significantly increase the level of 17ß-estradiol, but also improve the levels of progesterone, 17α-hydroxyprogesterone and androstenedione. Combined with molecular docking results and pharmacokinetic parameters, psoralen, isopsoralen and sweroside were considered as the key effective components of XLGB to activate adenylyl cyclase on promoting the biosynthesis of multiple sex steroid hormones. It is the first time to evaluate the regulatory effect of kidney-tonifying traditional Chinese medicine prescription on the levels of steroids in ovariectomy-induced osteoporosis rat, as well as the potential substance basis and mechanism of steroid hormone regulation.

The hypothalamic-pituitary-gonadal axis controls muscle stem cell senescence through autophagosome clearance.

BACKGROUND: With organismal aging, the hypothalamic-pituitary-gonadal (HPG) activity gradually decreases, resulting in the systemic functional declines of the target tissues including skeletal muscles. Although the HPG axis plays an important role in health span, how the HPG axis systemically prevents functional aging is largely unknown. METHODS: We generated muscle stem cell (MuSC)-specific androgen receptor (Ar) and oestrogen receptor 2 (Esr2) double knockout (dKO) mice and pharmacologically inhibited (Antide) the HPG axis to mimic decreased serum levels of sex steroid hormones in aged mice. After short-term and long-term sex hormone signalling ablation, the MuSCs were functionally analysed, and their aging phenotypes were compared with those of geriatric mice (30-month-old). To investigate pathways associated with sex hormone signalling disruption, RNA sequencing and bioinformatic analyses were performed. RESULTS: Disrupting the HPG axis results in impaired muscle regeneration [wild-type (WT) vs. dKO, P < 0.0001; Veh vs. Antide, P = 0.004]. The expression of DNA damage marker (in WT = 7.0 ± 1.6%, dKO = 32.5 ± 2.6%, P < 0.01; in Veh = 13.4 ± 4.5%, Antide = 29.7 ± 5.5%, P = 0.028) and senescence-associated ß-galactosidase activity (in WT = 3.8 ± 1.2%, dKO = 10.3 ± 1.6%, P < 0.01; in Veh = 2.1 ± 0.4%, Antide = 9.6 ± 0.8%, P = 0.005), as well as the expression levels of senescence-associated genes, p16Ink4a and p21Cip1 , was significantly increased in the MuSCs, indicating that genetic and pharmacological inhibition of the HPG axis recapitulates the progressive aging process of MuSCs. Mechanistically, the ablation of sex hormone signalling reduced the expression of transcription factor EB (Tfeb) and Tfeb target gene in MuSCs, suggesting that sex hormones directly induce the expression of Tfeb, a master regulator of the autophagy-lysosome pathway, and consequently autophagosome clearance. Transduction of the Tfeb in naturally aged MuSCs increased muscle mass [control geriatric MuSC transplanted tibialis anterior (TA) muscle = 34.3 ± 2.9 mg, Tfeb-transducing geriatric MuSC transplanted TA muscle = 44.7 ± 6.7 mg, P = 0.015] and regenerating myofibre size [eMyHC+ tdTomato+ myofibre cross-section area (CSA) in control vs. Tfeb, P = 0.002] after muscle injury. CONCLUSIONS: Our data show that the HPG axis systemically controls autophagosome clearance in MuSCs through Tfeb and prevents MuSCs from senescence, suggesting that sustained HPG activity throughout life regulates autophagosome clearance to maintain the quiescence of MuSCs by preventing senescence until advanced age.

Dietary α-Linolenic Acid-Rich Flaxseed Oil Exerts Beneficial Effects on Polycystic Ovary Syndrome Through Sex Steroid Hormones-Microbiota-Inflammation Axis in Rats.

Polycystic ovary syndrome (PCOS) represents a common endocrine-metabolic disorder disease with chronic low-grade inflammation and alteration of intestinal flora. Serving as functional food, flaxseed oil (FO), which is rich in plant-derived α-linolenic acid of omega-3 polyunsaturated fatty acids, has been proven to benefit for chronic metabolic diseases. However, the exact role of dietary FO on PCOS remains largely unclear. In the present study, 6-week-old female Sprague-Dawley rats were randomly divided into four groups (eight rats/group), including (a) pair-fed (PF) control (CON) group (PF/CON), (b) FO-fed CON group (FO/CON), (c) PF with letrozole-induced PCOS model (MOD) group (PF/MOD), and (d) FO-fed MOD group (FO/MOD). All rats were fed a standard diet. After 3 weeks of modeling and subsequent 8 weeks of treatment, the rats in diverse groups were euthanized and associated indications were investigated. The results showed that dietary FO ameliorated the disorder of estrous cycle and ovarian morphology. In parallel, dietary FO improved the sex steroid hormone disturbance (luteinizing hormone/follicle-stimulating hormone, estrogen, testosterone, and progesterone), body weights, dyslipidemia, and insulin resistance. Moreover, FO treatment improved plasma and ovary inflammatory interleukin (IL)-1ß, IL-6, IL-10, and IL-17A, tumor necrosis factor-α, and monocyte chemoattractant protein-1. Additionally, FO intervention significantly modulated the composition of gut microbiota and vaginal microbiota by increasing the abundances of Allobaculum, Lactobacillus, Butyrivibrio, Desulfovibrio, Bifidobacterium, Faecalibacterium, Parabacteroides as well as decreasing the abundances of Actinobacteria, Bacteroides, Proteobacteria, and Streptococcus, the ratio of Firmicutes/Bacteroidetes. A decrease in plasma lipopolysaccharide level and an increase in short-chain fatty acids, including acetic acid, propionic acid, butyric acid and pentanoic acid, were determined after dietary FO supplementation. Correlation analysis revealed close relationships among sex steroid hormones, inflammation, and gut/vaginal microbiota. Collectively, this study demonstrated that dietary FO ameliorated PCOS through the sex steroid hormones-microbiota-inflammation axis in rats, which may contribute to the understanding of pathogenesis and potentially serve as an inexpensive intervention in the control of PCOS.

Neuronal plasticity in the forebrain of the male red-sided garter snake: Effect of season, low temperature dormancy, and hormonal status on dendritic spine density.

Numerous studies have reported seasonal variations in regional morphology in the brains of seasonally breeding vertebrates. These alterations of neuronal morphology and dendritic spine density appear to be an active process within specific brain nuclei that regulate seasonal behaviors. In many cases, this neural plasticity has been found to be in response to changes in circulating sex steroid hormone levels and occur within pathways essential for the control of reproductive behaviors. Male red-sided garter snakes (Thamnophis sirtalis parietalis) (RSGS) exhibit a dissociated reproductive pattern where mating is initiated at a time when the gonads and steroidogenesis are inactive. And, although circulating levels of sex steroid hormones are elevated at the initiation of courtship and mating, the only known cue found to initiate courtship behavior and mating, is an extended period of low temperature dormancy (LTD) followed by exposure to warm temperatures. This study was designed to examine the role of seasons, sex steroid hormones, and LTD on neuronal and dendritic spine density within the anterior hypothalamus-preoptic area (AHPOA), a region shown to be critical for the regulation of reproductive behaviors. In the male RSGS, the density of dendritic spines on neurons in the AHPOA was significantly greater in spring, actively courting animals, than summer or fall, non-courting animals. Animals maintained under conditions of LTD exhibited significantly increasing spine density as time maintained in LTD increased. Animals receiving either testosterone or estradiol had a significantly greater density of dendritic spines than control animals. This study offers evidence suggesting that the "set up" of the pathways controlling courtship behavior and mating in the male RSGS, is not due solely to an extended period of LTD, but that an extended period of LTD in conjunction with circulating sex steroid hormones are critical for the initiation of reproductive behavior.

Influence of the hypothalamus-pituitary-gonadal axis reactivation and corresponding surging sex hormones on the amplitude of low-frequency oscillations in early pubertal girls: A resting state fMRI study.

BACKGROUND: There has been a myriad of neuroimaging studies that have suggested that pubertal stages and sex steroid fluctuations contribute to pubertal brain maturation. Investigations on the influence of hypothalamus-pituitary-gonadal (HPG) axis reactivation and the correlated elevated sex hormones on brain maturation have not unraveled these interactions to date. Here, we aimed to explore the impact of the reactivated HPG axis on spontaneous brain activity changes, by analyzing the amplitude of low-frequency fluctuation (ALFF) in developing girls aged 8-11 years old. METHODS: The gonadotropin-releasing hormone (GnRH) stimulation test was used to determine the HPG axis status and categorize subjects into two groups (HPG+ or HPG- group). Intelligence quotient (IQ) and the parent-rated Child Behavior Checklist (CBCL) were used to evaluate cognitive and behavioral performance. Two-sample t-tests were used to compare intergroup differences, the relations between brain areas' activities, age and hormonal levels were conducted by Pearson or Spearman correlation analyses. RESULTS: Compared with the HPG- group, the HPG+ group showed decreased ALFF values in the left superior temporal gyrus (STG) but increased ALFF values in the right superior frontal gyrus (SFG). In addition, in the HPG+ group, prolactin (PRL) levels were positively correlated with ALFF values in the right SFG, and there was significant negative correlation between ALFF values in the left STG and CBCL activities scores. LIMITATIONS: Due to the cross-sectional design of the present study, further study is needed to determine the relationships between age, reawakening of the HPG axis and related sex hormones and spontaneous brain activity change. CONCLUSIONS: These findings suggested that the reactivated HPG axis and elevated PRL level could affect changes in brain activity and this effect may be the neuroendocrine basis of mood, cognition, and social behavior changes in early pubertal girls.

Intravaginal treatment with Marantodes pumilum (Kacip Fatimah) ameliorates vaginal atrophy in rats with post-menopausal condition.

ETHNOPHARMACOLOGICAL RELEVANCE: Marantodes pumilum (MP) (Kacip Fatimah) is used to maintain the well-being of post-menopausal women. However, its role in ameliorating post menopause-related vaginal atrophy (VA) is unknown. AIMS: To investigate the ability of intravaginal MP gel treatment to ameliorate VA in sex-steroid deficient condition, mimicking post-menopause. METHODS: Ovariectomized female Sprague-Dawley rats received MP (100 µg/ml, 250 µg/ml and 500 µg/ml) and estriol (E) gels intravaginally for seven consecutive days. Rats were then euthanized and vagina was harvested and subjected for histological and protein expression and distribution analyses. Vaginal ultrastructure was observed by transmission electron microscopy (TEM). RESULTS: Thickness of vaginal epithelium increased with increasing intravaginal MP doses. Additionally, increased in expression and distribution of proliferative protein i.e. PCNA, tight junction protein i.e. occludin, water channel proteins i.e. AQP-1 and AQP-2 and proton extruder protein i.e. V-ATPase A1 were observed in the vagina following intravaginal MP and E gels treatment. Intravaginal MP and E gels also induced desmosome formation and approximation of the intercellular spaces between the vaginal epithelium. CONCLUSIONS: Intravaginal MP was able to ameliorate features associated with VA; thus, it has potential to be used as an agent to treat this condition.

Effects of triclosan (TCS) on hormonal balance and genes of hypothalamus-pituitary- gonad axis of juvenile male Yellow River carp (Cyprinus carpio).

Triclosan (TCS) is a broad spectrum antimicrobial agent which has been widely dispersed and determinated in the aquatic environment. However, the effects of TCS on reproductive endocrine in male fish are poorly understood. In this study, male Yellow River carp (Cyprinus carpio) were exposed to 0, 1/5, 1/10 and 1/20 LC50 (96 h LC50 of TCS to carp) TCS under semi-static conditions for 42 d. Vitellogenin (Vtg), 17ß-estradiol (E2), testosterone(T), gonadotropin (GtH), and gonadotropin-releasing hormone (GnRH) levels were measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, we also examined the mRNA expressions of aromatase, GtHs-ß, GnRH, estrogen receptor (Er), and androgen receptor (Ar) by quantitative Real-time Polymerase Chain Reaction (qRT-PCR). TCS induced Vtg levels of hepatopancreas, E2 levels of serum, and inhibited Ar and Er mRNA levels, suggesting that the induction of Vtg production by TCS was indirectly caused by non-Er pathways. TCS-induced Vtg levels by interfering with the reproductive axis at plenty of latent loci of male carps: (a) TCS exposure increased the aromatase mRNA expression of hypothalamus and gonad aromatase, consequently increasing serum concentrations of E2 to induce Vtg in hepatopancreas; (b) TCS treatment changed GtH-ß and GnRH mRNA expression and secretion, causing the disturbance of reproductive endocrine; (c) TCS exposure decreased Ar mRNA levels, indicating potential Ar-mediated antiandrogen action. These mechanisms showed that TCS may induce Vtg production in male carp by non-Er-mediated pathways.

[Molecular Mechanism Whereby Maternal Exposure to Dioxin Suppresses Sexual Maturation of the Offspring after Growing Up].

Dioxins, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), are responsible for producing serious toxic effects in the next generation, such as sexual immaturity. Our laboratory found that treating pregnant rats on gestational day 15 with TCDD (1 µg/kg orally) targets pituitary luteinizing hormone (LH) to attenuate testicular steroidogenesis in fetuses. Because sex steroids during a short window ("the critical period") in the perinatal stage stimulate brain differentiation closely linked to sexual maturation, it is likely that TCDD imprints sexual immaturity on the offspring due to the lowered expression of LH during the fetal period. To address this hypothesis, we first investigated the effect of supplementation of equine chorionic gonadotropin (eCG), an LH-mimicking hormone, in fetuses exposed to TCDD. The result showed that eCG ameliorated defects in sexual behavior in adulthood as well as in steroidogenesis during the fetal stage. We also found that maternal exposure to TCDD induced the pituitary expression of histone deacetylases (HDACs) in fetuses. In agreement with this, TCDD deacetylated the histones wrapped around the LHß gene, and valproic acid, an HDAC inhibitor, blocked the reduced level of LHß caused by TCDD. These observations strongly suggest that TCDD induces the expression of HDACs to attenuate fetal LH production. Finally, such a transient reduction in steroidogenesis of the pituitary-gonadal axis causes a decrease in the expression of hypothalamic gonadotropin-releasing hormone, resulting in defects in sexual behavior in adulthood. This review increases our understanding of the developmental toxicities caused by endocrine disruptors including dioxins.

Effects of chronic dietary petroleum exposure on reproductive development in polar cod (Boreogadus saida).

Increasing human activities in the Arctic raise the risk of petroleum pollution, thus posing an elevated risk for Arctic organisms to be chronically exposed to petroleum compounds. The endocrine disrupting properties of some of these compounds (i.e. polycyclic aromatic hydrocarbons [PAHs]) present in crude oil may have negative effects on the long and energy intensive reproductive development of polar cod (Boreogadus saida), an Arctic keystone species. In the present study, selected reproductive parameters were examined in feral polar cod exposed to crude oil via a natural diet (0.11, 0.57 and 1.14µg crude oil/g fish/day [corresponding to low, medium and high treatments, respectively]) for 31 weeks prior to spawning. Fish maturing in the current reproductive period made up 92% of the experimental population while 5% were immature and 3% were identified as resting fish. Phase I metabolism of PAHs, indicated by ethoxyresorufin-O-deethylase (EROD) activity, showed a dose-dependent increase in high and medium crude oil treatments at week 6 and 22, respectively. Decreasing EROD activity and increasing PAH bile metabolite concentrations over the experimental period may be explained by reproductive maturity stage. Significant alterations in sperm motility were observed in crude oil exposed males compared to the controls. The investigated somatic indices (gonad and hepatic), germ cell development and plasma steroid levels (estradiol-17ß [females], testosterone [males and females] and 11-ketotestosterone [males]) were not significantly altered by chronic dietary exposure to crude oil. The environmentally realistic doses polar cod were chronically exposed to in this study were likely not high enough to induce adverse effects in this ecologically important fish species. This study elucidated many baseline aspects of polar cod reproductive physiology and emphasized the influence of maturation state on biomarkers of PAH biotransformation (EROD and PAH bile metabolites).

Effects of temperature and fish oil supplementation on ovarian development and foxl2 mRNA expression in spotted scat Scatophagus argus.

In this study, the complete foxl2 complementary (c)DNA sequence was isolated by simple modular-architecture research tool (SMART)er rapid amplification of cDNA ends (RACE). Two year-old female spotted scat, Scatophagus argus, were reared at different temperatures (23, 26 and 29° C) for 6 weeks, or fed with different concentrations of dietary fish oil (0, 2 or 6%) for 8 weeks. Ovarian development, serum oestradiol-17ß (E2 ) levels, as well as ovarian foxl2 expression were measured. At the end of experiment, ovarian foxl2 messenger (m)RNA expression in fish reared at 23 and 26° C was significantly higher than that in fish reared at 29° C, and that in 2 and 6% fish oil groups was also significantly higher than that in control group (P < 0·05). Serum E2 levels exhibited the same trend with foxl2 mRNA expression in temperature treatment groups and fish oil fed groups. There was a significant positive correlation between stage of oocytes and foxl2 expressions. Results showed that from 23 to 29° C, the optimal temperature for ovarian development in S. argus was 23-26° C, and 6% fish oil supplementation could effectively promote ovarian development. Optimal temperature and fish oil supplement might increase ovarian foxl2 mRNA expressions to promote ovarian development in S. argus.

Cloning and expression analysis of tyrosine hydroxylase and changes in catecholamine levels in brain during ontogeny and after sex steroid analogues exposure in the catfish, Clarias batrachus.

Tyrosine hydroxylase (Th) is the rate-limiting enzyme for catecholamine (CA) biosynthesis and is considered to be a marker for CA-ergic neurons, which regulate the levels of gonadotropin-releasing hormone in brain and gonadotropins in the pituitary. In the present study, we cloned full-length cDNA of Th from the catfish brain and evaluated its expression pattern in the male and female brain during early development and after sex-steroid analogues treatment using quantitative real-time PCR. We measured the CA levels to compare our results on Th. Cloned Th from catfish brain is 1.591 kb, which encodes a putative protein of 458 amino acid residues and showed high homology with other teleosts. The tissue distribution of Th revealed ubiquitous expression in all the tissues analyzed with maximum expression in male and female brain. Copy number analysis showed two-fold more transcript abundance in the female brain when compared with the male brain. A differential expression pattern of Th was observed in which the mRNA levels were significantly higher in females compared with males, during early brain development. CAs, l-3,4-dihydroxyphenylalanine, dopamine, and norepinephrine levels measured using high-performance liquid chromatography with electrochemical detection in the developing male and female brain confirmed the prominence of the CA-ergic system in the female brain. Sex-steroid analogue treatment using methyltestosterone and ethinylestradiol confirmed our findings of the differential expression of Th related to CA levels.

Effects of fish oil on ovarian development in spotted scat (Scatophagus argus).

The effects of different concentrations of dietary fish oil (0, 2%, or 6%) on ovarian development in 2-year-old female Scatophagus argus were investigated. The levels of serum sex steroid hormones (estradiol-17ß, E2; testosterone, T), protein phosphorus (SPP), and protein calcium (SPC), as well as vitellogenin (vtg) mRNA expression in livers and ovaries were measured. Over the eight week experimental period, oocytes did not develop further and remained at phase III in fish fed with the control diet with no supplement of fish oil. Fish fed with 2% fish oil supplement had oocytes at transition phase from III to IV. Fish fed with 6% fish oil supplement had oocytes at late phase IV. Higher gonadosmatic index, serum E2, SPP, SPC, and liver vtg expression were found in 6% fish oil group compared to that in the 2% fish oil group (except E2) and the control group (P<0.05). In addition, vtg expression in livers was 600-1000 times higher than that in the ovaries. Gonadosmatic index, E2, and SPP, as well as liver vtg expression increased during the experiment and peaked at the end of experiment. However, hepatosomatic index, serum T, and ovarian vtg expression peaked at 4 weeks, and then decreased at 8 weeks, with no significant difference among the 3 groups. In summary, we showed that 6% fish oil supplementation in S. argus could effectively promote ovarian development, with associated increases in E2 secretion and increased liver vtg mRNA expression.