Estrogen receptors (ERs) are considered to mediate the ability of 17beta-estradiol (estradiol) to reduce injury-induced proliferation of vascular smooth muscle cells (VSMCs), leading to vascular lesions. However, the finding that estradiol attenuates formation of vascular lesions in response to vascular injury in knockout mice that lack either ER-alpha or ER-beta challenges this concept. Our hy...

A novel chemiluminescent enzyme immunoassay system, PATHFAST, for the measurement of estradiol in horses was evaluated. The concentrations of estradiol in the whole blood and serum of mares were measured using PATHFAST and the estradiol concentrations measured by PATHFAST were compared with those measured by a time-resolved fluoro-immunoassay (FIA). To monitor physiological changes, serum estra...

Two experiments were conducted to study the role of estradiol and progesterone in regulating steroid binding sites in sheep uterine myometrium. Exogenous estradiol increased the concentration of estradiol binding sites in nuclei and subsequently increased the total cell content of estradiol binding sites. Estradiol increased the number of progestogen binding sites (promegestone binding) and may...

Estradiol 17 beta prevented the fall in the microbicidal activity of the myeloperoxidase-H2O2-halide system induced by high H2O2 concentrations. In contrast, when the H2O2 (and halide) concentrations were low the myeloperoxidase-H2O2-halide antimicrobial system was inhibited by estradiol. These properties of estradiol 17 beta were shared by estradiol 17 alpha, estrone, estriol, ethinyl estradio...

A convenient homogeneous enzyme immunoassay for estradiol is described. Unlike heterogeneous immunoassays, which require time-consuming separation steps or expensive automated systems, homogeneous immunoassays, wherein all reagents are freely suspended in bulk solution, can be simple and fast without costly instrumentation. The key component of this assay system, an estradiol-reporter enzyme co...

We assessed the potential usefulness of 16a-[’25l]/3-estradiol in estradiol receptor assays as compared with a long-used [3H] -f3-estradiol dextran-coated charcoal method, measuring 472 consecutive human breast-cancer cytosols by both procedures. Six different preparations of 16 a-[125l]--estradiol were used. Nonspecific binding in five batches was similar and comparable to [3H]-/3-estradiol. A...

The purpose of this study was to determine the effects of 17-beta-estradiol on area postrema neuronal activity in vivo and on area postrema potassium currents (IK) in vitro. In anesthetized rats, intravenous injection of 17-beta-estradiol (10 ng/kg bw) -inhibited area postrema neuronal activity in 8/8 neurons tested. The averaged firing rate decreased from 2.9 +/- 1.1 to 1.1 +/- 0.3 Hz. The inh...

Isoflavones are phytoestrogens which have estrogen-like activity in animals and humans with structure similar to 17-β-estradiol and capable of binding to estrogen receptors (ERs).This experiment was conducted to demonstrate the effect of isoflavones on estradiol concentration in blood and its influence on the productive performances in ISA Brown laying hens fed with supplemented feed with large...