Search results for "Estrogen"
showing 10 items of 530 documents
Chapter 4 Cholesterol and steroid hormones: modulators of oxytocin receptor function
2002
The function and physiological regulation of the oxytocin-receptor system is strongly steroid-dependent. This is, unexpectedly, only partially reflected by the promoter sequences in the oxytocin receptor and favors the idea that posttranscriptional mechanisms may also play a significant role for the physiological regulation of the oxytocin-receptor system. Our data indicate that cholesterol acts as an allosteric modulator of the oxytocin receptor and stabilizes both membrane-associated and solubilized OT receptors in a high-affinity state for agonists and antagonists. Moreover, high-affinity OT receptors are 2-fold enriched in cholesterol-rich plasma membrane domains in HEK293 fibroblasts s…
Impact of osteoporosis and vertebral fractures on quality-of-life. a population-based study in Valencia, Spain (The FRAVO Study)
2011
Abstract Background To describe the health related quality of life in a population sample of postmenopausal women over the age of 50 and resident in the city of Valencia (Spain), according to the presence/absence of osteoporosis and the severity of prevalent morphometric vertebral fractures. Methods A cross-sectional age-stratified population-based sample of 804 postmenopausal women of 50 years of age and older were assessed with the SF-12 questionnaire. Information about demographic features, lifestyle, clinical features, educational level, anti-osteoporotic and other treatments, comorbidities and risk factors for osteoporosis were collected using an interviewer-administered questionnaire …
Correlates of hormone replacement therapy use in Italian women, 1992-1996
1999
we analyzed the determinants of hormonal replacement therapy (HRT) use in Italy for the period 1992-1996, using data from a framework of case-control studies of colon and rectal neoplasm.a total of 1574 women aged 45-74 years were considered. This group comprised women with acute, non neoplastic, non-hormone-related diseases admitted to a network of hospitals in six areas of Italy.a total of 146 women (8.5%) reported ever HRT use. The multivariate odds ratio (OR) of ever use was 1.6 (95% CI 1.0-2.6) for women with 12 years of education or more, compared with those with7 years. The frequency of use of HRT tended to decrease with increasing parity: the OR was 0.6 for women with four or more c…
Lack of binding of gestodene to estrogen receptor in human breast cancer tissue
1990
Competition studies with progesterone and estradiol receptors of human myometrial tissue as well as of mammary cancer tissue showed that gestodene bound with high affinity to the progesterone receptor, as did other synthetic and natural progestogens. However, gestodene did not bind to the estradiol receptor. The relative binding affinities of all tested synthetic and natural ligands showed no organ-specific differences and no differences between neoplastically transformed and normal tissues.
Risk of Parkinson disease in women: Effect of reproductive characteristics
2004
Objective: To investigate the association between some fertile life characteristics and Parkinson disease (PD) in women. Methods: Women affected by PD and control subjects were matched one to one by age (±2 years). One hundred thirty-one women with idiopathic PD and 131 matched control subjects were interviewed. Controls were randomly selected from the resident list of the same municipality of residence of cases. All subjects had a Mini-Mental State Examination score of ≥24. Cumulative length of pregnancies, age at menarche, age and type of menopause, and estrogen use before and after menopause were investigated in cases and controls through a structured questionnaire. Models of matched pai…
The effect of hormone replacement therapy and/or exercise on skeletal muscle attenuation in postmenopausal women: a yearlong intervention
2005
Hormone replacement therapy (HRT) has been reported to exert a positive effect on preserving muscle strength following the menopause, however, the mechanism of action remains unclear. We examined whether the mechanism involved preservation of muscle composition as determined by skeletal muscle attenuation. Eighty women aged 50-57 years were randomly assigned to either: HRT, exercise (Ex), HRT + exercise (ExHRT), and control (Co) for 1 year. The study was double-blinded with subjects receiving oestradiol and norethisterone acetate (Kliogest) or placebo. Exercise included progressive high-impact training for the lower limbs. Skeletal muscle attenuation in Hounsfield units (HU) was determined …
Combination of hormone replacement therapy and high physical activity is associated with differences in Achilles tendon size in monozygotic female tw…
2009
Estrogen concentration has been suggested to play a role in tendon abnormalities and injury. In physically active postmenopausal women, hormone replacement therapy (HRT) has been suggested to decrease tendon diameter. We hypothesized that HRT use and physical activity are associated with Achilles tendon size and tissue structure. The study applied cotwin analysis of fourteen 54- to 62-yr-old identical female twin pairs with current discordance for HRT use for an average of 7 yr. Achilles tendon thickness and cross-sectional areas were determined by ultrasonography, and tendon structural organization was analyzed from the images using linear discriminant analysis (LDA). Maximal voluntary and…
Early, but not late onset estrogen replacement therapy prevents oxidative stress and metabolic alterations caused by ovariectomy.
2014
Aims: The usefulness of estrogen replacement therapy (ERT) in preventing oxidative stress associated with menopause is controversial. We aimed to study if there is a critical time window for effective treatment of the effects of ovariectomy with estrogens at the molecular, metabolic, and cellular level. Results: Our main finding is that early, but not late onset of ERT prevents an ovariectomy-associated increase in mitochondrial hydrogen peroxide levels, oxidative damage to lipids and proteins, and a decrease in glutathione peroxidase and catalase activity in rats. This may be due to a change in the estrogen receptor (ER) expression profile: ovariectomy increases the ER α/β ratio and immedi…
Effects of hormone replacement therapy and high-impact physical exercise on skeletal muscle in post-menopausal women: a randomized placebo-controlled…
2001
An age-related decline in muscle performance is a known risk factor for falling, fracture and disability. In women, a clear deterioration is observed from early menopause. The effect of hormone replacement therapy (HRT) in preserving muscle performance is, however, unclear. This trial examined the effects of a 12-month HRT and high-impact physical exercise regimen on skeletal muscle in women in early menopause. A total of 80 women aged 50–57 years were assigned randomly to one of four groups: exercise (Ex), HRT, exercise+HRT (ExHRT) and control (Co). The exercise groups participated in a high-impact training programme. The administration of HRT (oestradiol/noretisterone acetate) or placebo …
Acute estradiol protects CA1 neurons from ischemia-induced apoptotic cell death via the PI3K/Akt pathway
2010
Global ischemia arising during cardiac arrest or cardiac surgery causes highly selective, delayed death of hippocampal CA1 neurons. Exogenous estradiol ameliorates global ischemia-induced neuronal death and cognitive impairment in male and female rodents. However, the molecular mechanisms by which a single acute injection of estradiol administered after the ischemic event intervenes in global ischemia-induced apoptotic cell death are unclear. Here we show that acute estradiol acts via the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling cascade to protect CA1 neurons in ovariectomized female rats. We demonstrate that global ischemia promotes early activation of glycogen syn…