Although cholesterol has been accepted as a precursor of the neutral steroid hormones, its role in estrogen formation has been subject to much doubt. It was postulated, on the basis of experiments in z&o in the pregnant mare, that cholesterol was not an estrogen precursor (1). The test animal had readily converted radioactive acetate to labeled estrogens, but had failed to convert administered ...

BACKGROUND Environmental estrogens alter hormone signaling in the body that can induce reproductive abnormalities in both humans and wildlife. Available testing systems for estrogens are focused on specific systems such as reproduction. Crucially, however, the potential for significant health impacts of environmental estrogen exposures on a variety of body systems may have been overlooked. OB...

BACKGROUND The Women's Health Initiative randomized clinical trial reported that menopausal hormone therapy increases lung cancer mortality risk. If this is true, use of anti-estrogens should be associated with decreased lung cancer mortality risk. The authors compared lung cancer incidence and mortality among breast cancer patients with and without anti-estrogen therapy. METHODS Our study in...

In animals and humans, estrogens are able to induce cancer in susceptible target organs, but the mechanism(s) of estrogen-induced carcinogenesis has not been elucidated. A well-known animal model is the development of renal carcinoma in estrogen-treated Syrian hamsters. Previous work demonstrated the presence of covalent DNA addition products (adducts) in premalignant kidneys of hamsters expose...

Progesterone and estrogens play key roles in regulating various physiological phenomena related to normal growth, development, and reproduction of domestic animals. This review focuses on the mechanisms by which progesterone and estrogens regulate the reproductive processes in these animals. The majority of research on the actions of progesterone and estrogens on the reproductive systems of cat...

Glucocorticoids and estrogens are two classes of steroid hormones that have essential but distinct physiologic functions. Estrogens also represent a risk factor for breast cancer. It has been suggested that glucocorticoids can attenuate estrogen responses, but the mechanism by which glucocorticoids inhibit estrogenic activity is unknown. In this study, we show that activation of glucocorticoid ...

Two small groups of steroids in the estrane series-here designated as impeded estrogens,-represent a class of compounds which differ from the majority of estrogenic substances in exerting certain unusual influences on growth of the uterus. The induction of these effects previously was considered to be peculiar to estriol. The unusual growth properties common to impeded estrogens are twofold: (a...

Cardiovascular disease, a generic denomination including coronary heart disease (CHD), stroke, and venous thromboembolic disease (VTED), has shown sensitivity to estrogens. The relative protection of women as compared with men has nourished a debate about a possible protective role for estrogens, but the prejudicial effects detected in clinical trials has created confusion on the risk/benefit r...

UV/H₂O₂, which is an advanced treatment technology used to reduce multiple contaminants, is effective in potable water treatment. Simultaneous degradation effects and kinetics of three types of coexisting micropollutant estrogens (steroid estrogens, SEs), including estrone (E1), 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2), in deionized water were studied. Experiments were carried out wit...

Sex-based differences in bronchial asthma can already be observed childhood, at which time allergic atopic is more frequently found boys than girls. In adulthood, higher prevalence of reported women, especially for the severe neutrophilic subtype associated with obesity, responds poorly to corticosteroids. seem attributable changing levels estrogens, progesterone, and testosterone, may exert ma...