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Despite that estradiol can reduce the risk of cardiovascular diseases in ovariectomized animals in the plains, its effect on animals at high altitude has seldom been reported. We hypothesize that estradiol can ameliorate cardiac damage to ovariectomized rats induced by chronic exposure to hypobaric hypoxia at high altitude. This study was intended to investigate whether cardiovascular magnetic resonance (CMR) imaging could reveal cardioprotective effect of estradiol on ovariectomized rats under chronic exposure to hypobaric hypoxia at high altitude. Thirty-two rats were randomized into the Control group (Plain), HH + Sham group (Hypobaric Hypoxia + Sham), HH + OVX group (Hypobaric Hypoxia + Bilateral Ovariectomy) and HH-OVX + E2 group (Hypobaric Hypoxia + Bilateral Ovariectomy + Estradiol, 50 μg/kg, 3 times a week, for 6 weeks) (n = 8 per group). Except the Control group (altitude: 500 m), rats in other groups were subcutaneously injected with 17β -estradiol or vehicle and exposed to chronic hypobaric hypoxia in Qinghai-Tibet Plateau (altitude: 4250 m), China, for 6 weeks. Biventricular cardiac function and global strain of the rats were measured by CMR and analyzed using the cine tissue tracking techniques. Biochemical tests, histopathology and electronic microscopy were used to evaluate the protective effect of estradiol on the heart tissue of ovariectomized rats exposed to a high-altitude environment. The biventricular ejection fraction and global strains decreased in the HH + OVX group compared with that in the Control group (all p < 0.05). All the aforementioned changes in the HH + OVX group ameliorated in the HH-OVX + E2 group (all p < 0.05). Estradiol also alleviated the right ventricular dilatation and hypertrophy in the HH + OVX group (all p < 0.05). In addition, histological and biochemical analyses also supported these in vivo results. Estradiol ameliorated the biventricular structural and functional damage in ovariectomized rats exposed to chronic hypobaric hypoxia at high altitude. [ABSTRACT FROM AUTHOR]

Objective: The role of estrogen in cognitive function and depressive symptoms is controversial due to discrepancies between results from randomized controlled trials (RCT) and observational studies. Mendelian randomization analysis may provide further insights concerning the role of estrogen in these outcomes as it assesses the effect of lifelong endogenous exposure but is less vulnerable to confounding than observational studies.Method: We used separate sample instrumental variable analysis to estimate the association of log 17β estradiol with cognitive function (Delayed 10 word recall, and Mini Mental State Examination (MMSE)) and depressive symptoms (Geriatric Depression Scale (GDS)) in older Chinese women of the Guangzhou Biobank Cohort Study (GBCS, n=3086). The estimate was derived based on the Wald estimator, the ratio of the association of genetic determinants (rs1008805 and rs2175898) of log 17β-estradiol with cognitive function and depressive symptoms in GBCS and the association of log 17β-estradiol with genetic determinants in the sample of young women in Hong Kong (n=236).Results: Genetically predicted 17β-estradiol was not associated with delayed 10-word recall (0.42 words per log increase in 17β-estradiol (pmol/L), 95% confidence interval (CI) -0.49 to 1.34) MMSE (0.39 per log increase in 17β-estradiol (pmol/L), 95% CI -0.87 to 1.65) or GDS (0.24 per log increase in 17β-estradiol (pmol/L), 95% CI -0.57 to 1.05).Conclusion: These results were largely consistent with evidence from RCTs and did not show any beneficial effect of estrogen on cognitive function and depressive symptoms. However, larger Mendelian randomization analyses are needed to identify any minor effects. [ABSTRACT FROM AUTHOR]

• 17β-Estradiol and 17α-Methyltestosterone affected the mRNA levels of sex hormone synthase Hc-Cyp17a in Hyriopsis cumingii. • Estradiol content were related to gonadal development of H. cumingii. • Hc-Cyp17a changed regularly during gonad development. • Hc-Cyp17 could play a vital role in the synthesis of sex hormones, sexual differentiation, gonadal development and functional maintenance of the H. cumingii. Estrogens and androgens that coexist in the aquatic environment could potentially affect shellfish, however, endocrine disrupting effects of them in shellfish are significant. As an important aquaculture shellfish in China, Hyriopsis cumingii has remarkable economic benefits. In this study, the effects of endocrine disrupting chemicals on the steroid synthase Hc-Cyp17a in the male and female gonads of the H. cumingii were assessed by exposing juvenile mussels to cultured waters containing 17β-Estradiol (E2) and 17α-Methyltestosterone (MT) for 28 days. At the same time, the E2 content in the four stages of gonadal development, the expression changes of Hc-Cyp17a in gonadal development and its localization in the mature gonad were measured to explore the relationship between genes and hormones. The results showed that both E2 and MT at 50 ng/L and 200 ng/L could affect the transcription level of Hc-Cyp17a , which was inhibited initially and promoted in post-development. E2 content was positively correlated with gonadal development stage, which was in mussel. By tracing the expression of Hc-Cyp17a , difference was found during different developmental periods. The expression level in ovary was higher than that in testis during gonadal development of 1/ 2/ 3-year-old mussels and showed an increasing trend with age. Furthermore, the expression levels in 6 tissues of mature individuals were measured and it showed that there was a significant difference between male and female in the gonads (p < 0.01). In situ hybridization, it suggested that Hc-Cyp17a was significantly signaled in the follicular wall and oocyte of female and in the follicular membrane of testis, respectively. These results could play a vital role in assessing and understanding the effects of aquatic environment on the endocrine system of H. cumingii. [ABSTRACT FROM AUTHOR]