Xenoestrogens, such as o,p'-DDT and octyl phenol (OP), have been associated with reproductive abnormalities in various wildlife species. Xenoestrogens mimic the natural estrogen 17 beta-estradiol and compete for binding to the estrogen receptor. Even though the affinity of o,p'-DDT and OP for the estrogen receptor is approximately 1000-fold lower than 17 beta-estradiol, the actions of xenoestro...

We have recently shown that uterine insulin-like growth factor I (IGF-I) gene expression is up-regulated by tamoxifen, a uterotrophic partial antagonist to the estrogen receptor, but down-regulated by the complete estrogen receptor antagonist ICI 182780, which causes uterine involution. This result is consistent with prior reports indicating that the uterotrophic effects of estradiol are mediat...

The human ovarian carcinoma cell lines PE01, PE04, and PE06 express the estrogen receptor and studies with the PE04 cells have shown that tamoxifen inhibits 17ß-estradiol-induced proliferation. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a broad spectrum antiestrogen which works through the aryl hydrocarbon receptor. Incubation of the three cell lines with | 'II11 ( 1)1) followed by isolatio...

Estradiol is an ovarian steroid hormone that regulates physiological functions in the central nervous system, including mood, cognition, sleep and mental state. Emerging evidence has revealed that there is an enrichment of cells that express the estrogen receptor in the lateral habenula (LHb) region, however, the precise biological functions of estradiol on neurons in the LHb remain to be eluci...

The purpose of this study was to determine whether estrogen modulates the function of vascular melatonin receptors. We used the rat caudal artery and found that the contractile effects of melatonin were influenced by the estrous cycle, ovariectomy, and estrogen replacement. In arterial ring segments isolated from female rats, melatonin potentiated, in a concentration-dependent manner, contracti...

Estradiol treatment increases the number of NMDA receptor binding sites, and changes evoked synaptic currents in a manner consistent with a steroid-induced functional enhancement of NMDA receptors in rat hippocampus. In this study, we investigate the cellular mechanisms of estradiol-induced NMDA receptor regulation at the protein and mRNA levels in ovariectomized rats treated with ovarian stero...

We previously reported that 17 beta-estradiol inhibits cytokine-stimulated bioassayable IL-6 and the steady-state level of IL-6 mRNA. To determine the molecular basis of this effect, the transient expression of chloramphenicol acetyltransferase (CAT) reporter plasmid driven by the human IL-6 promoter was studied here in HeLa or murine bone marrow stromal cells (MBA 13.2). 17 beta-estradiol (10(...

Some human breast cancers which contain estrogen receptors (ER) also contain progesterone receptors (PgR), whose presence may indicate that the ER remain responsive to estrogen and can still control specific protein synthesis. To demonstrate a direct role for ER we have used the human breast cancer cell line, MCF-7, which contains ER and low PgR levels. We have studied the effects of addition a...

Dissociated cultured rat hippocampal pyramidal neurons respond to estradiol with a time-dependent, twofold increase in density of their dendritic spines. This effect is mediated by an estrogen receptor, probably of the alpha nuclear receptor type. In searching for the molecular mechanisms leading from the initial activation of the estrogen receptor to the final formation of new dendritic spines...