BACKGROUND The present study was designed to determine if estrogens change microtubule polymerization and modulate cell cycle progression in vitro, related to modulation of tubulin expression and to determine if estrogens had antagonistic or synergistic effects with microtubule active agents. METHODS cDNA array analysis of LNCaP cells treated with the estrogens, estradiol, estrone, diethylsti...

Background: Estrogens include estoril (E3), estradiol and estrone (E1). These chemicals are produced in human and animal bodies as well as in synthetic chemicals (drugs). Estrogens can enter water sources in different ways. When these chemicals enter the human body through water and wastewater, they have the ability to mimic or disrupt the normal estrogen activities in humans and animals. Estro...

Estrogens play an important role in regulating the growth and differentiation of normal, premalignant and malignant cell types, especially breast epithelial cells, through interaction with two nuclear estrogen receptors (ERalpha and ERbeta). In this review, we present a brief overview of the actions of estrogens in the different steps of breast carcinogenesis, including cancer progression to me...

The rate of hypertension increases after menopause. Whether estrogen and progesterone deficiency associated with menopause play a role in determining a worst blood pressure (BP) control is still controversial. Also, studies dealing with the administration of estrogens or hormone therapy (HT) have reported conflicting evidence. In general it seems that, despite some negative data on subgroups of...

Aquatic environments receive significant levels of chemical contaminants generated by human activities. Among these pollutants, we noticed the xenobiotics known as reproductive toxicants and endocrine disruptors. The endocrine disruption in wildlife has been the subject of many reviews and workshops in recent years. Field observations of reproductively abnormal organisms and population declines...

High endogenous sexual hormone levels and use of medium potency estrogens are associated with a reduced risk of hip fracture in postmenopausal women. However, it is not clear if low potency estrogens confer the same benefits as the more widely used forms of menopausal hormone replacement. We examined the association between postmenopausal use of low potency estrogens, mainly estriol, and hip fr...

BACKGROUND This study compares the effect of estrogens and ACE inhibition on plasminogen activator inhibitor-1 (PAI-1) concentrations in healthy postmenopausal women, genotyped for a 4G/5G polymorphism in the PAI-1 promoter, a polymorphism shown to influence PAI-1 concentrations. Methods and Results- Morning estradiol, PAI-1, tissue plasminogen activator, plasma renin activity, angiotensin II, ...

2. Estrogenic activity can be assayed by measuring increases in uterine weight (“uterotrophic activity”) in immature or ovariectomised rodents. These models are used as they have low or no production of endogenous estrogens and are therefore, more sensitive to the administration of exogeneous estrogens. Advances in the age at which vaginal opening or first oestrus occurs in rodents is also used...

Estrogens are major risk factors for the development of breast cancer; they can be metabolized to catechols, which are further oxidized to DNA-reactive quinones and semiquinones (SQs). These metabolites are mutagenic and may contribute to the carcinogenic activity of estrogens. Redox cycling of the SQs and subsequent generation of reactive oxygen species (ROS) is also an important mechanism lea...

It has been assumed that estrogens act indirectly on the mammary glands because these hormones induce little or no growth of the breast tissues in hypophysectomized animals of most species.5s18 The results, however, have not been entirely uniform.2 Most investigators have noted an absence of mammary growth in those experiments in which hypophysectomized rats and mice have been given estrogens.'...