Search results for "Estradiol"
showing 10 items of 203 documents
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…
Estradiol, acting through estrogen receptor alpha, restores dimethylarginine dimethylaminohydrolase activity and nitric oxide production in oxLDL-tre…
2011
Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthase. ADMA accumulation, mainly due to a decreased dimethylarginine dimethylaminohydrolase (DDAH) activity, has been related to the development of cardiovascular diseases. We investigate whether estradiol prevents the changes induced by oxidized low density lipoprotein (oxLDL) on the DDAH/ADMA/NO pathway in human umbilical artery endothelial cells (HUAEC). HUAEC were exposed to estradiol, native LDL (nLDL), oxLDL and their combinations for 24 h. In some experiments, cells were also exposed to the unspecific estrogen receptor (ER) antagonist ICI 182780, the specific ERα antagonist MPP or specific agonists …
Effect of CYP1A1 Gene Polymorphisms on Estrogen Metabolism and Bone Density
2004
UNLABELLED: In this study, we evaluated the effect of polymorphisms of the CYP1A1 gene, linked to hormone-related cancers, on estrogen metabolism and BMD. We found that variants carrying the A allele (CA and AA) for the C4887A polymorphism have a significantly higher degree of estrogen catabolism and lower femoral BMD. INTRODUCTION: Polymorphisms of the CYP1A1 gene, one of the key enzymes that metabolize estrogen, have been linked with hormone-related cancers. We investigated the impact of these polymorphisms on estrogen metabolism and BMD, which is another hormone-dependent health issue. MATERIALS AND METHODS: One hundred seventy postmenopausal women (mean age, 63.5 +/- 0.6 years) particip…
Progestogens stimulate prostacyclin production by human endothelial cells.
2005
BACKGROUND: The effects of progestogens on endothelial physiology are poorly studied. Prostacyclin is a potent vasodilator synthesized by two isoforms of cyclooxygenase (COX) in endothelium. We examined the effects of two clinically used progestogens, progesterone and medroxyprogesterone acetate (MPA), on prostacyclin production by cultured human umbilical vein endothelial cells (HUVEC) and the possible role of progesterone receptors and both COX enzymes. METHODS: Cells were exposed to 1-100 nmol/l of either progesterone or MPA and prostacyclin production was measured in culture medium. RESULTS: Both progestogens significantly increased prostacyclin release in a time- and dose-dependent man…
Estradiol Stimulates Vasodilatory and Metabolic Pathways in Cultured Human Endothelial Cells
2009
Vascular effects of estradiol are being investigated because there are controversies among clinical and experimental studies. DNA microarrays were used to investigate global gene expression patterns in cultured human umbilical vein endothelial cells (HUVEC) exposed to 1 nmol/L estradiol for 24 hours. When compared to control, 187 genes were identified as differentially expressed with 1.9-fold change threshold. Supervised principal component analysis and hierarchical cluster analysis revealed the differences between control and estradiol-treated samples. Physiological concentrations of estradiol are sufficient to elicit significant changes in HUVEC gene expression. Notch signaling, actin cyt…
Pure anti-oestrogens
2000
Pure anti-oestrogens are a group of at least five new compounds which are able to antagonize the effects of oestrogen in all tissues and species studied. The mechanism by which the pure anti-oestrogens produce their effects remains in question, but all of them are competitive antagonists of the oestrogen receptors and, moreover, have been proposed to block the shuttling of oestrogen receptors into the cell nucleus. When studied in vitro, these compounds are able to block the oestrogen-stimulated growth of breast cancer cells. In animals, their ability to block the effects of oestrogen on breast, uterus, bone, cardiovascular system and other reproductive-associated tissues has been demonstra…
Transferrin gene expression in the mammary gland of the rat. The enhancing effect of 17 beta-oestradiol on the level of RNA is tissue-specific.
1993
We have investigated the physiological factors which regulate transferrin gene expression in the mammary gland of the rat. Our studies by dot blot analysis have demonstrated that multiple doses of 17β-oestradiol (OE2; 0·5 mg/kg per day for 3 days) elicit a specific 3·5-fold increase in the transferrin mRNA levels in the mammary glands of virgin rats. The hormonal action of OE2 in mammary tissue was specific for the transferrin gene, as judged by hybridization with β-actin cDNA. The accmulation of transferrin mRNA induced by OE2 treatment was similar to the developmentally regulated expression of the gene observed during the reproductive cycle. The steady-state level of mammary transferrin m…
Estradiol, progesterone, 17-hydroxyprogesterone, androstenedione and CA125 in patients with ovarian carcinoma.
1992
Estradiol, progesterone, 17-hydroxyprogesterone, androstenedione and CA125 were assayed in 25 women (12 oophorectomized before entering the study) with ovarian carcinoma. The data from patients were ordered according to the presence or absence of the gonads. The patients with ovaries (Group A) showed significantly higher levels of estradiol (p less than 0.01), progesterone (p less than 0.01) and 17-hydroxyprogesterone (p less than 0.01) than controls. This difference was not observed between oophorectomized patients (Group B) and controls. CA125 levels were significantly higher in patients that in controls (p less than 0.001) irrespective of the ovarian status of the patients. Eleven patien…
Influence of Menstrual Cycle or Hormonal Contraceptive Phase on Energy Intake and Metabolic Hormones—A Pilot Study
2021
Sex hormones are suggested to influence energy intake (EI) and metabolic hormones. This study investigated the influence of menstrual cycle (MC) and hormonal contraceptive (HC) cycle phases on EI, energy availability (EA), and metabolic hormones in recreational athletes (eumenorrheic, NHC = 15 and monophasic HC-users, CHC = 9). In addition, 72-h dietary and training logs were collected in addition to blood samples, which were analyzed for 17β-estradiol (E2), progesterone (P4), leptin, total ghrelin, insulin, and tri-iodothyronine (T3). Measurements were completed at four time-points (phases): Bleeding, mid-follicular (FP)/active 1, ovulation (OVU)/active 2, mid-luteal (LP)/inactive in NHC/C…