The estrogenic effect of zearalenone derivatives was investigated for their binding characteristics to cytosol and nuclear receptors in the uterus. Competition with 17beta-estradiol at the cytosol receptor sites was observed in four of the six derivatives tested, namely trans- and cis-zearalenone, zearalenol, and zearalanol. The other two, 8'-hydroxyzearalenone and 6'-aminozearalene, lacked the...

To determine the effects of gonadal hormones on proliferation of the hippocampal neural cells, which are of importance in learning and memory function. 17β-Estradiol or testosterone was added to the culture at various concentrations. Their proliferation and protective effects on the neural cell were determined with BrdU, flow cytometry and MTT assay. Effects of the gonadal hormones on brain-der...

The presence of estrogen receptor beta and aromatase in the germ cell has highlighted the physiological role of the traditionally female hormone, estrogen, in spermatogenesis. Estrogen receptor alpha knockouts and aromatase knockouts have further accentuated the role of estrogen in germ cell maturation. To delineate the direct action of estrogen in the seminiferous epithelium, we studied the ef...

OBJECTIVE Cannabinoids are a class of compounds that have the ability to activate two specific receptor subtypes, the cannabinoid CB1 and CB2 receptors. CB1 receptor is a G-protein-coupled receptor that is linked to the signal transduction pathways. The cumulative effects of this receptor have important implications in the control of cell survival and cell death having the potential to regulate...

Accumulating evidence suggests that insulin-like growth factor-I (IGF-I) and estradiol interact to regulate neural function. In this review, we focus on the cellular and molecular mechanisms involved in this interaction. The expression of estrogen receptors (ERs) and IGF-I receptor is cross-regulated in the central nervous system and many neurons and astrocytes coexpress both receptors. Further...

We compared three radioligands for use in a cytoplasmic estrogen-receptor assay, using pooled cytosol from human breast adenocarcinomas. The estrogen receptor content was determined in vitro by a dextran-coated charcoal method involving a 4-h incubation with and without diethylstilbestrol. Tritiated moxestrol failed to come to equilibrium in 4 h, thereby preventing the use of conventional one-c...

The present data show that tamoxifen and nafoxidine compete specifically with estradiol for the estrogen receptor in the fetal uterus of the guinea pig. Furthermore, [3H]tamoxifen binds to the cytosol macromolecules of this fetal tissue at two classes of binding sites, one with a dissociation constant (Kd) of 1.8 +/- 0.4 x 10(-9) M and a concentration of specific binding sites (n) of 1800 +/- 1...

We have established or characterized six lines of human breast cancer maintained in long-term tissue culture for at least 1 year and have examined these lines for estrogen responsiveness. One of these cell lines, MCF-7, shows marked stimulation of macromolecular synthesis and cell division with physiological concentrations of estradiol. Antiestrogens are strongly inhibitory, and at concentratio...

Background: Melatonin as the major hormone produced by the pineal gland has a significant role in mammalian reproduction. In this study the efficacy of melatonin coadministration with nicotine on mouse follicogenesis was investigated. Materials and Methods: A total of 32 Female adult NMRI mice were divided into four groups. The control group (n=8) received vehicle, group 2 (n=8) received nicoti...

Urokinase plasminogen activator (UK-PA) is a serine protease implicated in cancer invasion and metastasis. In this investigation, patients with breast cancers containing high levels of UK-PA antigen had significantly higher risk of early disease recurrence and shorter overall survival than did patients with low levels of the protein. In univariate analysis, UK-PA was a more powerful discriminat...