The purpose of this study was to investigate the vasorelaxing effect and mechanism of idoxifene (a new estrogen receptor modulator) on human internal mammary artery (HIMA). HIMA segments were harvested from men during coronary artery bypass grafting surgery. Patients with diabetes mellitus, hypercholesterolemia, hypertension, or smoking habit were excluded. The vasorelaxing effect of idoxifene on artery rings from HIMA with and without endothelium was measured by means of perfusion in vitro. Cumulative dose-response to idoxifene in the range of 0.01-10 micromol/L was observed in the presence and absence of NO synthase inhibitor L-NAME. It was also studied whether the vasodilation effect of idoxifene on HIMA was blocked by methylene blue (MB), an inhibitor of guanylate cyclase (GC). The results obtained from idoxifene were compared with those from 17beta-estradiol (E(2)). It was found that idoxifene caused a concentration-dependent relaxation on HIMA. The dose range was from 0.03 micromol/L (minimal vasodilatory concentration) to 3 mmol/L (maximal vasodilatory concentration). It was also found that the vasorelaxation effect of idoxifene on HIMA was dependent on endothelium. E(2) (0.1-100 micromol/L) also resulted in an endothelium-dependent vasorelaxation, but the vessels were 15-fold less sensitive to E(2) than to idoxifene in their vasorelaxation responses. The EC(50) for E(2) was 4.65+/-0.34 micromol/L, compared with 0.32+/-0.02 micromol/L for idoxifene. The mean maximal vasodilatory value of E(2) was 88.3+/-5.7%, compared with 88.6+/-7.2% for idoxifene. Pretreatment with L-NAME (100micromol/L) abolished idoxifene-induced vasodilation virtually by blocking nitric oxide production. The vasorelaxing effect of idoxifene disappeared in the presence of MB (10 micromol/L). These findings demonstrate that idoxifene results in an endothelium-dependent vasorelaxation of HIMA, like estrogen. The effect of idoxifene is more potent than that of traditional estrogen, and is possibly mediated by NO-GC-cGMP pathway.
Estrogen Antagonists ; pharmacology ; Humans ; Mammary Arteries ; drug effects ; physiology ; Tamoxifen ; analogs & derivatives ; pharmacology ; Vasodilation ; drug effects

OBJECTIVETo study the effects of exogenous ER beta on the growth of breast cancer MCF-7 cells under different treatment.

METHODSAn eukaryotic expression vector containing 1.6 kb of human entire coding sequence of ER beta (pCDNA3-ER beta) was transfected into human breast cancer MCF-7 cells using lipofectamine 2000. The biological activity of ER beta was detected with the luciferase reporter containing estrogen responsive element (ERE) and the expression of ER beta protein by Western blot. The growth properties of MCF-7, pCDNA 3-transfected MCF-7 and pCDNA 3-ER beta-transfected MCF-7 cells under different treatment, including E2 (17beta-estradiol) and 4-OHT (4-hydroxytamoxifen), were observed.

RESULTSA stronger activation of the reporter by ER beta in the presence of E2 was observed in the pCDNA 3-ER beta-transfected MCF-7 cells than in the pCDNA 3-transfected MCF-7 and in MCF-7 cells. Western blot analysis showed that the protein level of ER beta in the pCDNA 3-ER beta-transfected MCF-7 cells was markedly increased. Exogenous ER beta expression did not change the growth properties and the morphology of MCF-7 cells under normal condition. The pCDNA 3-ER beta-transfected MCF-7 cells proliferated at the same rate as naive cells in the presence of 4-OHT, whereas a strong inhibition of the proliferation of the pCDNA 3-ER beta-transfected MCF-7 cells in the presence of E2 was observed.

CONCLUSIONExogenous ER beta expression does not increase the resistance to 4-OHT, and a strong inhibition of the proliferation may occur in the presence of E2.

Breast Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Estradiol ; pharmacology ; Estrogen Antagonists ; pharmacology ; Estrogen Receptor beta ; genetics ; metabolism ; Female ; Humans ; Tamoxifen ; analogs & derivatives ; pharmacology ; Transfection

OBJECTIVETo study the inhibitig effects of genistein on the growth of human breast cancer cell lines in vitro and its mechanisms. METHORD: Human breast cancer cell lines both MCF-7(positive estrogen receptor, ER+) and MDA-MB-231 (negative estrogen receptor, ER-) were cultured in vitro. The proliferation of cells was measured with MTT methord and the growth curve was drawn with cell count. The estrogen receptor in cells was show with immunohistochemistry.

RESULTGenistein inhibited proliferation of MCF-7 and MDA-MB-231 cell lines and inhibition was dependent on dose within some concentration range, IC50 being 32.5 mumol.L-1 and 46.8 mumol.L-1 respectively. Genisteins antiproliferation of MCF-7 was stimulated by ectogenesis estrogen but proliferation of MDA-MB-231 inhibited by geinstein was not related to estrogen. The positive signs of ER in cellular nuclei of MCF-7 cell line fed with genistein at concentration of 30 mumol.L-1 were significantly weaker than these not fed with genistein.

CONCLUSIONGenistein obviously inhibits proliferation of both cell lines of MCF-7 and MDA-MB-231 in vitro and is dependent on dose. Genisteins antiproliferous effect on MCF-7 cell lines is stimulated by estrogen and this effect is related with ER, but genisteins inhibiting proliferation of MDA-MB-231 cell line is not through ER.

Antineoplastic Agents, Phytogenic ; pharmacology ; Breast Neoplasms ; chemistry ; pathology ; Cell Division ; drug effects ; Estrogen Antagonists ; pharmacology ; Female ; Genistein ; pharmacology ; Humans ; Inhibitory Concentration 50 ; Receptors, Estrogen ; analysis ; Tumor Cells, Cultured

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Estrogen Antagonists ; pharmacology ; Glioma ; pathology ; Humans ; Protein Kinase C ; antagonists & inhibitors ; Tamoxifen ; pharmacology

The human transforming growth factor-3 (TGF-3) is an important cytokine to maintain bone mass by inhibiting osteoclast differentiation. Recently raloxifene response element (RRE), a new enhancer with a polypurine sequence for estrogen receptor (ER)-mediated gene activation, was identified on the TGF-3 gene. Functional analysis of the RRE-mediated pathway has shown that this would be an important pathway for bone preserving effect. We found a novel mutation in the RRE sequence by single-strand conformational polymorphism analysis in one of 200 Korean women. Cloning and sequencing revealed a heterozygote in which one allele had an insertion of 20 nucleotides (AGAGAGGGAGAGGGAGA GGG) between nucleotide +71 and +72 and a point mutation at nucleotide +75 (G-A transition), and the other allele had normal sequence. The insertion was a nearly perfect tandem duplication of the wild type DNA sequence. The bone mineral density of the affected woman was not much lower than that of age-matched controls. Transient transfection of the mutant allele showed no significantly different activity compared with that of the wild type allele. These observations suggest that the heterozygote variation of the RRE sequence seems not to be operative in determination of bone mass.
Estrogen Antagonists/*pharmacology ; Female ; Human ; Middle Age ; *Mutation ; Raloxifene/*pharmacology ; *Response Elements ; Transfection ; Transforming Growth Factor beta/*genetics

Carnosol has been proved to have anti-breast cancer effect in previous research. But its ER subtype's specific regulation and mediation mechanisms remain unclear. The aim of this study is to observe the effect of carnosol on cell proliferation and its estrogen receptor α and β's specific regulation and mediation mechanisms with ER positive breast cancer T47D cell. With estrogen receptor α and β antagonists MPP and PHTPP as tools, the MTT cell proliferation assay was performed to observe the effect of carnosol on T47D cell proliferation. The changes in the T47D cell proliferation cycle were detected by flow cytometry. The effect of carnosol on ERα and ERβ expressions of T47D cells was measured by Western blot. The findings showed that 1 x 10(-5)-1 x 10(-7) mol x L(-1) carnosol could significantly inhibit the T47D cell proliferation, which could be enhanced by MPP or weakened by PHTPP. Meanwhile, 1 x 10(-5) mol x L(-1) or 1 x 10(-6) mol x L(-1) carnosol could significantly increase ERα and ERβ expressions of T47D cells, and remarkably increase ERα/ERβ ratio. The results showed that carnosol showed the inhibitory effect on the proliferation of ER positive breast cancer cells through target cell ER, especially ERβ pathway. In the meantime, carnosol could regulate expressions and proportions of target cell ER subtype ERα and ERβ.
Blotting, Western ; Breast Neoplasms ; metabolism ; pathology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Diterpenes, Abietane ; chemistry ; pharmacology ; Dose-Response Relationship, Drug ; Estrogen Receptor Modulators ; pharmacology ; Estrogen Receptor alpha ; antagonists & inhibitors ; metabolism ; Estrogen Receptor beta ; antagonists & inhibitors ; metabolism ; Female ; Flow Cytometry ; Humans ; Molecular Structure ; Pyrazoles ; pharmacology ; Pyrimidines ; pharmacology

OBJECTIVETo determine the effects of raloxifene hydrochloride (RLX) on bone mineral density (BMD), bone metabolism markers and serum lipids in healthy postmenopausal women in Beijing.

METHODSA multicenter, randomized, double-blind, placebo-controlled study was conducted in a total of 204 healthy postmenopausal women (age 59.5 +/- 5.0 years and weight 62.8 +/- 8.7 kg) treated with either RLX 60 mg (n = 102) or placebo (n = 102) daily for 12 months. BMD, serum lipids, and bone markers were measured before and after drug administration.

RESULTSCompared with placebo, RLX produced a significant increase in both total lumbar spine and total hip BMD. For the lumbar spine, percentage increase in total BMD was 2.3% with RLX compared with a decrease of 0.1% with placebo (P < 0.001). Corresponding values for total hip BMD were a 2.5% increase for RLX and a 1.1% increase for placebo (P = 0.011). For biochemical markers of bone metabolism, serum osteocalcin and C-telopeptide, percentage decreases were 27.65% and 24.02% in RLX-treated subjects. Corresponding values in placebo were a 10.64% decrease and a 15.75% increase (RLX compared with placebo, both P < 0.001). For total cholesterol and low-density lipoprotein cholesterol levels, percentage decreases were 6.44% and 34.58% in the RLX-treated group. Corresponding values in placebo-treated patients were a 1.44% increase and a 19.07% decrease (RLX compared with placebo, both P < 0.001). No differences were found for high-density lipoprotein cholesterol or triglyceride levels between the two groups. Only 5 subjects discontinued early owing to an adverse event (3 in the RLX group and 2 in the placebo group).

CONCLUSIONSThis study confirms that RLX exerts positive effects on the skeleton, increasing BMD and decreasing biochemical markers of bone metabolism, and has a positive effect on the overall serum lipid profile in postmenopausal women in China.

Aged ; Biomarkers ; blood ; Bone Density ; drug effects ; Bone and Bones ; metabolism ; China ; Estrogen Antagonists ; pharmacology ; Female ; Humans ; Lipids ; blood ; Middle Aged ; Postmenopause ; physiology ; Raloxifene Hydrochloride ; pharmacology ; Selective Estrogen Receptor Modulators ; pharmacology

OBJECTIVETo study the effect of purariae isoflavone on estrogen level in ovariectomized rats.

METHOD80 rats were divided into four groups randomly, every group with 20 rats: 1. Control group; 2. Normal + purariae isoflavone group; 3. Ovariectomized group; 4. Ovariectomized + purariae isoflavone group. Estrogen level and gonadotropin-releasing hormone level of all rats were measured.

RESULTThirty days after being ovariectomized, E2, E3 level was significantly lower than that of the first group(P < 0.05). But Testerone, FSH, LH, PRL and GH increased(P < 0.05). After being gastrogavaged with purariae-isolfavone for thirty days, Estrogen level and gonadotropin-relasing hormone level of the second group were significantly lower in various degree than those of normal control group (P < 0.05). But in ovariectomized rats, the estrogen level was recovered (P > 0.05). The gonadotropin-releasing hormone level was increased (P < 0.05).

CONCLUSIONPurariae-isoflavone can increase estrogen level to normal in ovariectomized rats by way of increasing the level of gonadotropin-releasing hormone. In normal rats, it has anti-estrogen effect.

Animals ; Estradiol ; blood ; Estriol ; blood ; Estrogen Antagonists ; pharmacology ; Female ; Gonadotropin-Releasing Hormone ; blood ; Isoflavones ; isolation & purification ; pharmacology ; Ovariectomy ; Plants, Medicinal ; chemistry ; Pueraria ; chemistry ; Rats ; Rats, Sprague-Dawley

Soy-isoflavones may act as estrogenic agonists or antagonists depending on the endogenous hormone status. These clinical effects can be exerted variably in individuals by the metabolic ability to produce a more potent metabolite than precursors. The objective of this randomized, double-blind, placebo-controlled study was to investigate the skeletal effect of isoflavones according to their metabolic variability in premenopausal women. Volunteers were randomly assigned to receive either soy-extract isoflavones (n=32) or lactose (n=21) once a day for three menstrual cycles. After intervention, the urinary excretions of isoflavones and their metabolites were significantly higher in the soy group than in the placebo group and showed a large inter-individual variation. Women in the soy group were divided into subgroups according to their ability to excrete more potent metabolites. Serum osteocalcin and urine deoxypyridinoline showed a tendency to increase after a challenge in equol high-excretors. Serum osteocalcin concentration in the genistein high-excretors increased significantly after a challenge (P=0.04) but did not increase in either the placebo or genistein low-excretors. An estrogenic antagonistic effect of isoflavones on bone turnover was observed in premenopausal women who are able to produce more potent metabolites.
Adult ; Amino Acids/urine ; Bone and Bones/*drug effects/metabolism ; Double-Blind Method ; Estrogen Antagonists/*pharmacokinetics/pharmacology/urine ; Female ; Humans ; Isoflavones/*pharmacokinetics/pharmacology/urine ; Middle Aged ; Osteocalcin/blood ; *Premenopause

OBJECTIVETo explore the molecular mechanism of jiantai liquid (JTL) in improving endometrial receptivity of mice with embryo implantation dysfunction (EID).

METHODSMice model of EID induced by mifepristone were intervened with JTL (Twig of Chinese Taxillus, Red Sage root, Chinese Angelica, Milkvetch root, Chuanxiong rhizome), and sacrificed on day 8 of pregnancy. The endometrial estrogen receptor (ER) and progesterone receptor (PR) protein and their gene expressions were assessed by Western blot and semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTSLevels of ER and PR protein and their gene expressions in the JTL treated group were significantly higher than those in the model group respectively (all P < 0.05), and showed insignificant difference from those in the normal control group (all P > 0.05).

CONCLUSIONJTL could promote the development of endometrium and improve the embryo implantation by way of regulating the levels of ER and PR protein and gene expression in mice with EID.

Animals ; Drugs, Chinese Herbal ; pharmacology ; Embryo Implantation ; drug effects ; Female ; Luteolytic Agents ; antagonists & inhibitors ; pharmacology ; Male ; Mice ; Mifepristone ; antagonists & inhibitors ; pharmacology ; Receptors, Estrogen ; biosynthesis ; genetics ; Receptors, Progesterone ; biosynthesis ; genetics ; Uterus ; metabolism