Search results for "Estrogens"

Nitrosoureas Modes of Action and Perspectives in the Use of Hormone Receptor Affine Carrier Molecules

1989

Mechanisms of DNA adduct formation by antineoplastic 2-chloroethyl-N-nitrosoureas (CNUs) and of DNA damage induced by these compounds are discussed. CNUs are alkylating agents that form DNA-DNA cross-links as well as 2-chloroethylated and 2-hydroxyethylated adducts, the N-7-position of guanine being the predominantly alkylated site. A close correlation exists between the potential of a given compound to induce DNA-DNA cross-links and its antineoplastic effectiveness. However, levels of DNA-DNA cross-linking in bone marrow and extent of myelosuppression as measured in rodents are also closely correlated. The design of new cross-linking analogues capable of directing the antineoplastically re…

Multiple Estrogen Function in Human Prostate Cancer Cells

1996

Why Women Have More Alzheimer's Disease Than Men: Gender and Mitochondrial Toxicity of Amyloid-β Peptide

2010

The main risk factors for developing Alzheimer's disease (AD) are age and gender. The incidence of the disease is higher in women than in men, and this cannot simply be attributed to the higher longevity of women versus men. Thus, there must be a specific pathogenic mechanism to explain the higher incidence of AD cases in women. In this regard, it is notable that mitochondria from young females are protected against amyloid-beta toxicity, generate less reactive oxygen species, and release less apoptogenic signals than those from males. However, all this advantage is lost in mitochondria from old females. Since estrogenic compounds protect against mitochondrial toxicity of amyloid-beta, estr…

Oral homeostasis disruption by medical plasticizer component bisphenol A in adult male rats.

2013

Objectives/Hypothesis Bisphenol A (BPA) is a synthetic estrogen-like chemical mimetic widely used in the manufacture of polycarbonate plastics and epoxy resins found in numerous consumer products including food packaging, medical devices, and dental sealants. Because it is recovered in fluids and it can reach high levels in saliva, this study aimed to evaluate its safety on oral homeostasis by examining its effects on salivary glands, mouth epithelium, water consumption, and salt preference, each parameter being estrogen sensitive. Study Design Randomized controlled trial involving rats. Methods A dose-response study was conducted in adult Wistar rats randomized into five groups (n = 12). B…

Relaxant Effects of the Selective Estrogen Receptor Modulator, Bazedoxifene, and Estrogen Receptor Agonists in Isolated Rabbit Basilar Artery

2016

We have previously shown that the selective estrogen receptor modulator, bazedoxifene, improves the consequences of ischemic stroke. Now we aimed to characterize the effects and mechanisms of action of bazedoxifene in cerebral arteries. Male rabbit isolated basilar arteries were used for isometric tension recording and quantitative polymerase chain reaction. Bazedoxifene relaxed cerebral arteries, as 17-β-estradiol, 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol [estrogen receptor (ER) α agonist], and G1 [G protein-coupled ER (GPER) agonist] did it (4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol > bazedoxifene = G1 > 17-β-estradiol). 2,3-Bis(4-hydroxyphenyl)-propionitrile (E…

Estrogens inhibit angiotensin II-induced leukocyte-endothelial cell interactions in vivo via rapid endothelial nitric oxide synthase and cyclooxygena…

2002

Angiotensin II (Ang II) may be a key molecule in the development of atherosclerosis. Because the incidence of coronary atherosclerosis in premenopausal women is lower than that observed in men or postmenopausal women, we have investigated the effect of estrogens on Ang II–induced leukocyte recruitment in vivo using intravital microscopy in the rat mesenteric microcirculation. Superfusion for 60 minutes with Ang II induced a significant increase in leukocyte rolling flux, adhesion, and emigration. Administration of 17-β-estradiol (17-β-E) after 30 minutes of Ang II superfusion produced a reduction of these leukocyte responses by 55.1%, 72.7%, and 70.9%, respectively, an additional 30 minutes…

Dietary cholesterol and estrogen administration elevate brain apolipoprotein E in mice by different mechanisms.

2009

Apolipoprotein (apo) E plays an important role in the whole body cholesterol homeostasis. Recent studies suggest that it may also be involved in the local cholesterol transport in the brain, and influence the pathogenesis of Alzheimer's disease (AD) by interacting with the beta-amyloid protein and brain lipoprotein receptors. Since apoE expression is highest in the brain, next only to the liver and associated with the pathogenesis of AD, we hypothesized that dietary and hormonal intervention, known to regulate hepatic apoE expression may also regulate brain apoE and thereby influence local cholesterol transport. To test this hypothesis, groups of male C57BL mice were fed either regular rode…

Acute effects of three isoflavone class phytoestrogens and a mycoestrogen on cerebral microcirculation.

2007

Phytoestrogens and mycoestrogens are naturally occurring plant and fungus secondary metabolites with estrogen-like structure and/or actions. We aimed to check the hypothesis that phytoestrogens and mycoestrogens, due to their ability to elicit cerebral vasodilation, can induce acute increases in brain blood perfusion. For this purpose, we continuously recorded cerebrocortical perfusion by laser-Doppler flowmetry in anesthetized rats receiving intracarotid infusions (1 mg/kg) of one of the following estrogenic compounds: biochanin A, daidzein, genistein or zearalanone. We have shown the ability of two isoflavone class phytoestrogens (daidzein and biochanin A) and the mycoestrogen zearalanone…

Mitochondria from females exhibit higher antioxidant gene expression and lower oxidative damage than males

2003

We have investigated the differential mitochondrial oxidative stress between males and females to understand the molecular mechanisms enabling females to live longer than males. Mitochondria are a major source of free radicals in cells. Those from female rats generate half the amount of peroxides than those of males. This does not occur in ovariectomized animals. Estrogen replacement therapy prevents the effect of ovariectomy. Mitochondria from females have higher levels of reduced glutathione than those from males. Those from ovariectomized rats have similar levels to males, and estrogen therapy prevents the fall in glutathione levels that occurs in ovariectomized animals. Oxidative damage…

TFOS DEWS II Sex, Gender, and Hormones Report

2017

One of the most compelling features of dry eye disease (DED) is that it occurs more frequently in women than men. In fact, the female sex is a significant risk factor for the development of DED. This sex-related difference in DED prevalence is attributed in large part to the effects of sex steroids (e.g. androgens, estrogens), hypothalamic-pituitary hormones, glucocorticoids, insulin, insulin-like growth factor 1 and thyroid hormones, as well as to the sex chromosome complement, sex-specific autosomal factors and epigenetics (e.g. microRNAs). In addition to sex, gender also appears to be a risk factor for DED. “Gender” and “sex” are words that are often used interchangeably, but the…