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PubMed1979

A correlation between estrogen sulfotransferase levels and estrogen receptor status in human primary breast carcinoma.

Estrogen sulfotransferase (EC 2.8.2.4) activity and estrogen receptor levels were measured in 32 human primary breast cancer cytosol preparations. Two types of tumors were identified: type 1, in which estrogen sulfotransferase levels were low (less than 40 pmol 17 beta-estradiol 3-sulfate formed per mg protein per 2 hr) and were independent of [35S]adenosine 3'-phosphate 5'-phosphosulfate production from [35S]sulfate and adenosine triphosphate, and type 2, in which estrogen sulfotransferase levels ranged from 50 to 200 pmol 17 beta-estradiol 3-sulfate per mg protein per 2 hr and were correlated with [35S]adenosine 3'-phosphate 5'-phosphosulfate formation (r = 0.70; p less than 0.005). In type 1 tumors, 11 of 16 were estrogen receptor negative; in type 2 tumors, 2 of 16 were receptor negative. Estrogen sulfotransferase levels in receptor-negative tumors were significantly lower than the levels in receptor-positive tumors (p = 0.025).

Breast Neoplasms↗
PubMed1976

Ultrastructural characteristics of the vaginal epithelium of neonatally estrogenized mice in response to subsequent estrogen treatment.

Adult mice which had received 10 daily injections of 20 microng estradiol beginning with the day of birth were in a "persistent-estrous" state, showing ovary-independent proliferation and cornification of the vaginal epithelium. Ultrastructural changes of the vaginal epithelium in neonatally estrogenized mice was examined after a single postpuberal injection of 10 microng estradiol and compared with those seen in normal mice to estrogen. In ovariectomized normal mice, the basal cells were round. The nucleus was polygonal and contained peripheral condensed chromatin. After estradiol treatment, the basal cells became columnar. The nucleus was round to oval, containing dispersed chromatin. In neonatally estrogenized ovariectomized mice, the basal layer of vaginal epithelium consisted of round cells with polygonal nuclei, much as in normal ovariectomized mice. The nucleus occupied a large area of the cytoplasm and contained prominent nucleoli. Intercellular spaces were moderately distended. Late estradiol treatment resulted in distended intercellular spaces and in the appearance of the other cell type along with round cells in the basal layers: the columnar cells containing an oval nucleus with dispersed chromatin, resembled the basal cells in normal ovariectomized mice receiving postpuberal estrogen injection. The intercellular spaces between the columnar cells were narrow compared with those between round cells. However, the nuclei of round cells still had prominent nucleoli and peripheral condensed chromatin regardless of subsequent estrogen treatment. This fact suggests that these nuclei do not respond to estrogen. These results clearly show that the vaginal epithelium of neonatally estrogenized mice with ovary-independent persistent cornification consists of a mixed population of cells.

Animals↗
PubMed1975

Ultraviolet photosensitivity of the estrogen binding protein from rat uterus. Wavelength and ligand dependence. Photocovalent attachment of estrogens to proteins.

Ultraviolet irradiation of the estrogen binding protein in rat uterine cytosol results in a progressive photoinactivation which is rapid at 254 nm and slower at greater than 315 nm. Both unfilled and estradiol-filled sites are inactivated at approimately the same rates at 254 nm (t 1/2 equals 8 min and 11 min, respectively), but at 315 nm, empty sites are consumed much more rapidly (t 1/2 equals 3.4 hr) than filled ones (t 1/2 equals 24 hr). The protective effect of the estrogen ligand at this wavelength appears to depend on its binding to the estrogen-specific binding site, as inactivation rate studies at different concentrations of estrone, estradiol, and estriol show a good correlation between the extent of protection and the fractional saturation of the high affinity estrogen binding sites. Scatchard analysis indicates that inactivation is the result of a loss of binding sites and not a decrease in their affinity, and sedimentation analysis shows that increased heterogeneity and aggregation of the estrogen binding species accompanies the photoinactivation process. Photoinactivation appears to be the result of direct irradiative damage of the animo acid residues, as the inactivation rate is the same under air and nitrogen atmospheres, and is unaffected by nucleophiles, reductants, and radical scavengers. When photoinactivation is measureed by irradiation of cytosol containing [3-H]estradiol, a concurrent photocovalent attachment process is noted; the steroid becomes linked to protein in a solvent-extractable manner (boiling ethanol inextractable). This attachment, however, does not appear to be related to the steroid binding at the estrogen binding site. Its rate is affected by reductants and scavengers. A similar photocovalent attachment reaction occurs when bovine serum albumin or ovalbumin is irradiated in the presence of [3-H]estradiol or [3-H]diethylstilbestrol. The detailed reactions involved in this photocovalent attachment process have not been defined at present.

Animals↗
PubMed1979

Estrogenic activity of the insecticide chlordecone (Kepone) and interaction with uterine estrogen receptors.

The chlorinated insecticide chlordecone (Kepone) interacts with the estrogen receptor system in the rat uterus in vitro and in vivo. It competes with estradiol for binding to the cytoplasmic receptor in vitro and also induces nuclear accumulation of estrogen receptor sites in uteri in vitro. When injected into immature rats, chlordecone translocates estrogen receptor sites to the uterine nucleus, increases uterine weight, and stimulates the synthesis of the progesterone receptor, an estrogen receptor-mediated process. Its slow onset of action but prolonged duration of interaction with estrogen receptor and stimulation of uterine weight gain and progesterone receptor synthesis indicates that, although it has an affinity for receptor only 0.01-0.04% that of estradiol, its considerable estrogenic activity may likely be derived from its long half-life and bioaccumulative character.

Animals↗
PubMed1979

The presence of a cytoplasmic estrogen receptor in sexually mature rabbit epididymides: comparison with the estrogen receptor in immature rabbit epididymal cytosol.

Cytosol prepared from epididymides of castrated adult rabbits contains an estrogen-specific binding component that sediments in the 4--5S region on 0.01 M KCl sucrose gradients. The estrogen-specific binding component is not detectable on sucrose gradients unless the cytosol-[3H]estradiol mixture is first extracted with charcoal to remove uncomplexed and rapidly exchangeable ligand from the sample. The macromolecular bound [3H]estradiol that remains after charcoal extraction dissociates from the receptor with a dissociation half-time of greater than 24 h and is of high affinity (Kd = 6.5 +/- 0.9 X 10(-9) M). The estrogen receptor in the adult rabbit epididymis can also be demonstrated when charcoal-extracted samples are chromatographed on Sephadex G-200. Using this system, the major estrogen-specific binder has an apparent molecular weight of less than 200,000. In contrast, the epididymal estrogen receptor in sexually immature rabbits sediments as an 8S species on low salt gradients and has an apparent molecular weight of 200,000 or greater when assessed by chromatography on Sephadex G-200. The estrogen receptor in both age groups is distributed along the length of the epididymal duct. The highest concentration of the cytoplasmic receptor in both mature and immature rabbits is in the cauda epididymidis. The age-dependent changes in the amount of the receptor suggest that it may be involved in maturational changes in the epididymis. The alterations in the physicochemical properties may reflect physiological changes in the epididymis or in the endocrine status of the animal.

Aging↗
PubMed1976

Estrogen-receptor binding: relationship to estrogen-induced responses.

The relationship between nuclear binding of the receptor-estrogen complex (R-E) and estrogenic responses was examined. Nuclear-bound R-E was measured by the [3H] estradiol exchange assay, which permits the quantification of R-E as a function of either endogenous or non labeled estrogen. The quantity of nuclear R-E fluctuated as a function of blood levels of estrogen during the estrous cycle in the rat. This indicates that the accumulation of the R-E complex by the nucleus of uterine cells may be of physiologic significance and under the control of endogenous estrogen.

Animals↗
PubMed1979

Estrogen receptors and effects of estrogen on membrane electrical properties of coronary vascular smooth muscle.

The effect of estrogen stimulation in vitro on the electrical properties of vascular smooth muscle (VSM), and the concentration of estrogen receptors in VSM were measured in isolated coronary arteries. Microelectrode measurements of the dog coronary artery membrane potential (Em) showed quiescent values of -51 millivolts (mV) and an input resistance (rin) of 10 megohms. Addition by diethylstilbestrol (DES) at 10(-6) M hyperpolarized the membrane to -64 mV and reduced input resistance (rin) to 5 megohms within 15 minutes. Extrapolation of the Em vs. log [K]o curve to zero potential gave similar values of [K]i of around 170 mM in both normal and DES treated muscles suggesting that the DES induced hyperpolarization is not due to increased Na-K pump activity. The 0.5% ethanol vehicle alone had no effect on the membrane potentials. Tetraethylammonium ion (TEA) induced action potentials in the previously quiescent tissue. When DES was applied in the presence of TEA, the membrane potential increased and the action potentials were abolished. Scatchard analysis of the estrogen receptor binding demonstrated both a high and a low affinity receptor for estrogen in the VSM. These data indicate that DES hyperpolarizes the VSM cells by a mechanism other than an increased Na-K pump activity. The mechanism of this increased Em may be due to factors which increase K+ conductance either mediated directly through estrogen interaction with its cytosolic receptors or through some unidentified second mechanism.

Action Potentials↗
PubMed1978

Hepatic estrogen and progesterone receptors in an estrogen-associated hepatic neoplasm.

A patient with a benign hepatic neoplasm developing after treatment with estrogenic hormones is described. After excision, the neoplastic tissue was analyzed for the presence of cytosol estrogen and progesterone binding proteins. The neoplasm was classified as focal nodular hyperplasia of the liver and was demonstrated to contain high-affinity cytosol estrogen and progesterone hormone receptors. The estrogen-binding affinity of the neoplasm was three times greater than that of normal liver. Further investigation of cytosol hormone receptors in estrogen associated hepatic neoplasms will be required to define the role of these binding proteins in the possible etiology of certain liver tumors.

Clinical Trials as Topic↗
PubMed2014

Upregulation of TLR2 expression is induced by estrogen via an estrogen-response element (ERE).

TLR2 and estrogen are both thought to be involved in the pathogenesis of RA; however, it is unknown if there is an association between estrogen and TLR2. In this report, we treated PMA-differentiated THP-1 cells with 17β-estradiol (E2) and observed increases in TLR2 mRNA and protein levels by real-time quantitative PCR and western blot. Transfection of THP-1 cells with a series of 5'-deleted TLR2 promoter-luciferase constructs revealed that E2 enhanced TLR2 transcriptional activity in an estrogen receptor alpha (ERα)-dependent pattern. An estrogen receptor response element (ERE) was identified 251 bases upstream of the TLR2 promoter, and electrophoretic mobility shift assay and chromatin immunoprecipitations showed ERα binding was increased by E2. In summary, this work demonstrated that TLR2 is a new estrogen-regulated gene whose expression is upregulated through the interaction of ERα with an ERE in the promoter region.

Cell Line↗
PubMed2019

Estrogen-independent molecular actions of mutant estrogen receptor 1 in endometrial cancer.

Estrogen receptor 1 (ESR1) mutations have been identified in hormone therapy-resistant breast cancer and primary endometrial cancer. Analyses in breast cancer suggest that mutant ESR1 exhibits estrogen-independent activity. In endometrial cancer, ESR1 mutations are associated with worse outcomes and less obesity, however, experimental investigation of these mutations has not been performed. Using a unique CRISPR/Cas9 strategy, we introduced the D538G mutation, a common endometrial cancer mutation that alters the ligand binding domain of ESR1, while epitope tagging the endogenous locus. We discovered estrogen-independent mutant ESR1 genomic binding that is significantly altered from wild-type ESR1. The D538G mutation impacted expression, including a large set of nonestrogen-regulated genes, and chromatin accessibility, with most affected loci bound by mutant ESR1. Mutant ESR1 is distinct from constitutive ESR1 activity because mutant-specific changes are not recapitulated with prolonged estrogen exposure. Overall, the D538G mutant ESR1 confers estrogen-independent activity while causing additional regulatory changes in endometrial cancer cells that are distinct from breast cancer cells.

CRISPR-Cas Systems↗
PubMed1976

Calculation of estrogen excretion rates from urinary estrogen to creatinine ratios.

1. The excretion of estrogens by 42 menstruant and 7 pregnant (1st trimester) women ranged from 2 - 550 mug/24hr. 2. These changes were followed by measuring estrogen to creatinine ratios in small samples of urine. 3. Values of the ratio changed little in each 24 hr, and correlated closely with daily estrogen output (r = 0.971; P less than 0.001; estrogens (mug/24hr) =(see article. 4. The data suggests that ovarian activity in women, including those given gonadotropins to induce ovulation, may be followed by measuring estrogen to creatinine ratios in small samples of urine; the collection of 24 hr samples is unnecessary.

Circadian Rhythm↗
PubMed1978

Replacement estrogen therapy for menopausal vasomotor flushes. Comparison of quinestrol and conjugated estrogens.

Quinestrol, conjugated estrogens, or placebo was used to treat 156 patients with pernicious vasomotor instability in a prospective, double-blind, randomized, multiinvestigator trial. Vasomotor flushes were severe in approximately 80% of the cases and moderate in 20%, relatively equally distributed among the various drug groups. Both qinestrol and conjugated estrogens were significantly more effective than placebo in relieving vasomotor symptoms (by chi2 analysis, P less than or equal to 0.05). Greatest improvement was seen in the group receiving the higher once weekly quinestrol dosage of 0.2 mg followed by the group on the lower quinestrol dosage of 0.1 mg once weekly and the group on conjugated estrogens, 1.25 mg daily for 21 days on and 7 days off. No significant difference in relief of vasomotor flushes was shown between the active drug groups. No drug-related complications or side reactions of significance occurred. The results indicate that once weekly quinestrol is effective in relieving the vasomotor symptoms of the menopause. Either of two once weekly quinestrol regimens is an effective as conjugated estrogens given daily in a cyclic manner and therefore offers an alternative form of exogenous estrogen therapy.

Chemical Phenomena↗
PubMed1978

Cytoplasmic estrogen receptors and estrogen concentrations in bovine uterine endometrium.

Specific cytoplasmic binding of 17beta-[3H]estradiol ([3H]E2beta) by unoccupied receptors in bovine uterine endometrium was determined by saturation analysis and correlated with endometrium levels of E2beta in 21 cows. The concentrations of these estrogen receptors (ER) during the estrous cycle were significantly greater during proestrus, estrus, and postestrus (days 18-20 and 0-4 of the cycle) than during the midluteal period (days 10-12; P less than 0.05). These increases in ER concentration paralleled increases in endometrial and plasma E2beta concentrations. In a preliminary experiment involving six heifers killed during the estrous cycle, a comparison of the ER concentrations of the horns ipsilateral and contralateral to the corpus luteum showed no significant differences, as did a study of the dissociation constant of the steroid-receptor interaction during the estrous cycle and early pregnancy. The order of inhibition of cytoplasmic binding of [3H]E2beta by estrogens was as follows: E2beta greater than E1 greater than E2alpha greater than E3 at 4 C. The concentration of ER in six pregnant animals was higher on days 2-3 than on days 13-14 after insemination, which was similar to that found in cycling animals; however, the difference between days was not significant. Ovariectomy of two heifers resulted in slightly higher ER concentrations than in intact heifers, whereas immunization of two heifers with an E2beta conjugate resulted in levels 2-fold higher. In these altered animals plasma progesterone (P4) was nearly nondetectable. ER concentration was inversely related to the level of plasma P4 in cycling heifers (r = -0.58, P less than 0.01). Endometrial estrogen and plasma estrogen levels were also inversely correlated with plasma P4 levels (r = -0.65, P less than 0.01 and r = -0.48, P less than 0.05, respectively). Thus, if P4 level influences ER levels, the hormone may make the tissue less responsive to ovarian estrogens at such time as the luteal phase of the cycle and during pregnancy.

Animals↗
PubMed1976

Plasma precursors of estrogen. III. Conversion of plasma dehydroisoandrosterone to estrogen in young nonpregnant women.

The utilization of plasma dehydroisoandrosterone for estrogen production was studied in 4 normal young nonpregnant women and in one young surgical castrate woman. The mean transfer constant for total conversion to estrogen, [sigma] DE-BU' was 0.0016 of which about one third (0.0005) could be accounted for by conversion of dehydroisoandrosterone first to plasma androstenedione which in turn was converted to estrone. The remaining fractional conversion appeared to result principally in estradiol formation via a pathway probably not involving plasma androstenedione. The conversion of plasma dehydroisoandrosterone to estrogen was similar in the surgical castrate to that observed in the ovulating women. It is concluded that plasma dehydroisoandrosterone is converted to estrogen at extraglandular site(s) but this contribution represents only a minor fraction of total estrogen production in normal young women.

Androstenedione↗
PubMed1979

Long-term estrogenization in mammals. I. Histopathology of kidney, bladder, adrenals, and gonads; polydipsia; body weight; and serum levels of corticosterone and testosterone in estrogenized Marsh mice.

Single, sublethal, long-acting doses of estrone or estradiol cypionate produced the following histologic, behavioral, and blood chemistry effects in Marsh mice: (a) Bladder pathology developed following estrogen-induced polydipsia but was not consistently associated with kidney damage. (b) This polydipsia was more intense (a maximum of 250% over control intake) when the housing was in metal cages with floor screens than in plastic cages with bedding. Water intake of control mice was unaffected by housing changes. (c) Comparing litter-mate 2.5-month-old males and females, body weight loss following estrogen administration was transient with the females. With males, initial weight losses as compared with weight gains in the controls were demonstrated over a 20-week period. (d) Estrogenization markedly increased corticosterone and decreased testosterone serum levels with a significant negative correlation for these levels in the estrogenized mice. A significant positive correlation was also observed between testosterone levels and testis weights in the estrogenized mice.

Adrenal Glands↗
PubMed1977

Blood production rates of estrogens in women with differing ratios of urinary estrogen conjugates.

On the basis of the ratios of the estrogen conjugates in their urine (estriol/estrone + estradiol: E3/[E1+E2]), 19 women were divided into two groups: 9 women had ratios less than 0.6 and 10 women had ratios greater than 1.3. All women had measurements made of endogenous estrogens in their plasma by radioimmunoassay. They were then given constant infusions of 3H-estrone, 3H-estradiol and 14C-estriol during days 5-7 and days 20-22 of their cycles, and metabolic clearance rates (MCR) and blood production rates (PB) of estrone, estradiol and estriol were determined. Despite the wide disparity in their ratios of urinary estrogens, no differences could be found between the groups for the MCR's and PB's for all estrogens at either time of the cycle. The mean ratios of PB's (PB3/[PB2+PB1]) of estrone, estradiol and estriol ranged from 0.07 to 0.10 for each group during the cycle. The amounts of estriol entering the blood are small compared to the amounts of estrone and estradiol and do not correlate with the ratios of their urinary conjugates.

Adult↗
PubMed1976

[Total estrogens and estrogen-creatinine ratio in pregnancy].

The ratio of estrogen excretion in urine (milligrams per 24 h) divided by creatinine (grams per 24 h) was determined in 571 specimens of 307 pregnant women and compared with total estrogen determinations. Use of estrogen-creatinine ratio reduced the daily variations of total estrogen values by one third resulting in a mean curve with less standard deviation.

Circadian Rhythm↗
PubMed1978

Comparative studies on two combination oral contraceptives, one containing synthetic estrogen, the other "natural" estrogens.

Two combined oral contraceptives, one containing ethinyl estradiol and the other micronized estradiol and estriol, were compared by measuring a variety of endocrine and renal parameters over nine months. Significant changes were observed in plasma renin activity (P.R.A.) on the synthetic estrogen. Much larger changes were observed in the total urinary estrogens on patients taking the "natural" estrogens reflecting the amount of estrogens required to be excreted in the urine.

Adult↗