The fragmentation pathways of five estrogens (estradiol, estrone, equilin sulfate, 17 a-dihydroequilin sulfate and equilenin sulfate) have been studied with high resolution and high mass accuracy using electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF/MS) in the negative ion mode. Molecular weights were obtained from [M-H](-) ions in the product ion spectra. The results indicate that the five structurally similar estrogens have similar fragmentation pathways. Using their stable isotope forms as internal reference compounds, the accurate mass and composition of the fragment ions were determined. During collision-induced dissociation (CID), cleavage is initiated by loss of oxygen atoms from carbon-17, after which D and C rings cleave sequentially and rearrange to finally form stable conjugate structures with highly abundant characteristic fragment ions at m/z 183 (accompanied by m/z 181), m/z 169 and m/z 145 (accompanied by m/z 143). Understanding these characteristic fragmentation pathways of estrogens will be helpful in identifying the structures of steroid hormones in general.
Chemical Fractionation ; methods ; Equilenin ; chemistry ; Equilin ; analogs & derivatives ; chemistry ; Estradiol ; chemistry ; Estrogens ; chemistry ; Estrone ; chemistry ; Ions ; Spectrometry, Mass, Electrospray Ionization

OBJECTIVETo study 17β-estradiol (E2), ethinylestradiol (EE2), estriol (E3), estrone (E1) on MCF-7 proliferation effects, and compare the effects of independent action (IA) model with concentration addition (CA) model in assessing the combined effects of estrogen.

METHODSThe combinations of E2 + EE2, E2 + E3 and E2 + E1 were chosen and the cellular proliferation effects were examined by MTT assay.

RESULTSThe maximum proliferation effects at dose of 10⁻⁹ mol/L was 325.48% for E2, 330.34% for EE2, 255.22% for E3, and 199.61% for E1. In the E2 + EE2, E2 + E3, E2 + E1 groups, the results of IA model analysis were very close to the experimental results. The IA model tend to overestimated the experimental results, while the CA model often underestimated the experimental results. In the EC (E2, 30) + C (EE2, 70) group, the results exceed the maximum estrogen effects of E2, while in other groups, the results were lower.

CONCLUSIONSThe estrogenic effects of the four tested substances from high to low efficiency were that: EE2 > E2 > E3 > E1. The effect of IA model in predicting the combined effects of binary mixture was better than CA model. A small proportion of binary mixture showed synergy.

Cell Line, Tumor ; Cell Proliferation ; drug effects ; Estradiol ; pharmacology ; Estriol ; pharmacology ; Estrogens ; pharmacology ; Estrone ; pharmacology ; Ethinyl Estradiol ; pharmacology ; Female ; Humans

Bioidentical hormone therapy (BHT) refers to the use of hormones that are molecularly and chemically identical to endogenous hormones for purposes of hormone replacement therapy. The specific hormones used in BHT include estrone, estradiol, estriol, progesterone and testosterone. Since the result of the Women's Health Initiative (WHI) trial documented the increased risk of breast cancer, cardiovascular disease and stroke in users of conventional hormone therapy (CHT), use of CHT has declined and there has been increased interest in BHT. Bioidentical hormones have some distinctly different physiologic effects compared with synthetic hormones. Synthetic progestin is associated with an increased risk for breast cancer and cardiovascular disease, while natural progesterone is associated with a decreased risk of breast cancer and cardiovascular disease. Estriol has some unique physiologic effects, which differentiate it from estrone and estradiol. Estriol is associated with a lower risk of breast cancer and would be expected to prevent breast cancer, but few randomized controlled trials have been documented. Some clinical data demonstrate that BHT is associated with a lower risk of breast cancer and cardiovascular disease, and is more efficacious than synthetic hormones. However, there is little evidence in support of this claim. Moreover, estriol has not been approved by the U.S. Food and Drug Administration (FDA). Further studies are needed to confirm the safety and efficacy of BHT.
Breast Neoplasms ; Butylated Hydroxytoluene ; Cardiovascular Diseases ; Estradiol ; Estriol ; Estrone ; Female ; Hormone Replacement Therapy ; Humans ; Menopause ; Progesterone ; Stroke ; Testosterone ; United States Food and Drug Administration ; Women's Health

Bioidentical hormone therapy (BHT) refers to the use of hormones that are molecularly and chemically identical to endogenous hormones for purposes of hormone replacement therapy. The specific hormones used in BHT include estrone, estradiol, estriol, progesterone and testosterone. Since the result of the Women's Health Initiative (WHI) trial documented the increased risk of breast cancer, cardiovascular disease and stroke in users of conventional hormone therapy (CHT), use of CHT has declined and there has been increased interest in BHT. Bioidentical hormones have some distinctly different physiologic effects compared with synthetic hormones. Synthetic progestin is associated with an increased risk for breast cancer and cardiovascular disease, while natural progesterone is associated with a decreased risk of breast cancer and cardiovascular disease. Estriol has some unique physiologic effects, which differentiate it from estrone and estradiol. Estriol is associated with a lower risk of breast cancer and would be expected to prevent breast cancer, but few randomized controlled trials have been documented. Some clinical data demonstrate that BHT is associated with a lower risk of breast cancer and cardiovascular disease, and is more efficacious than synthetic hormones. However, there is little evidence in support of this claim. Moreover, estriol has not been approved by the U.S. Food and Drug Administration (FDA). Further studies are needed to confirm the safety and efficacy of BHT.
Breast Neoplasms ; Butylated Hydroxytoluene ; Cardiovascular Diseases ; Estradiol ; Estriol ; Estrone ; Female ; Hormone Replacement Therapy ; Humans ; Menopause ; Progesterone ; Stroke ; Testosterone ; United States Food and Drug Administration ; Women's Health

PURPOSE: The goal of this paper is to present the design and performance of a position encoding circuit for 16 x 16 array of position sensitive multi-anode photomultiplier tube for small animal PET scanners. This circuit which reduces the number of readout channels from 256 to 4 channels is based on a charge division method utilizing a resistor array. MATERIALS AND METHODS: The position encoding circuit was simulated with PSpice before fabrication. The position encoding circuit reads out the signals from H9500 flat panel PMTs (Hamamatsu Photonics K.K., Japan) on which 1.5 x 1.5 x 7.0 mm3 L0.9GSO (Lu1.8Gd0.2SiO5:Ce) crystals were mounted. For coincidence detection, two different PET modules were used. One PET module consisted of a 29 x 29 L0.9GSO crystal layer, and the other PET module two 28 x 28 and 29 x 29 L0.9GSO crystal layers which have relative offsets by half a crystal pitch in x- and y-directions. The crystal mapping algorithm was also developed to identify crystals. RESULTS: Each crystal was clearly visible in flood images. The crystal identification capability was enhanced further by changing the values of resistors near the edge of the resistor array. Energy resolutions of individual crystal were about 11.6%(SD 1.6). The flood images were segmented well with the proposed crystal mapping algorithm. CONCLUSION: The position encoding circuit resulted in a clear separation of crystals and sufficient energy resolutions with H9500 flat-panel PMT and L0.9GSO crystals. This circuit is good enough for use in small animal PET scanners.
Animals ; Estrenes ; Fees and Charges ; Optics and Photonics ; Pyridinium Compounds

This study was performed to examine if the effects of collagen supplementation from pork skin could improve the sex steroid hormone, serum lipid and skin crack in Korean middle-aged women. Middle-aged women (40-55 years) who were not diagnosed with any type of disease were included in this study and thirty subjects were randomly assigned to a control group (n = 15) or a collagen supplemented group (n = 15). The collagen supplemented group ingested collagen flour 2 g, 3 times a day for 12 weeks. We measured serum collagen, estrogen, estradiol, estriol, progesterone, total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol concentration. The collagen supplementation group had significantly increased serum collagen (p < 0.05) compared with the control group. In addition, skin crack was improved. But, there were no differences for sex steroid hormone and lipid profile in control and collagen supplemented groups. The result of the present study demonstrated that supplementation of 6 g collagen per day for 12 weeks can give beneficial effects on skin crack reduction and serum collagen concentration.
Cholesterol ; Collagen ; Estradiol ; Estriol ; Estrogens ; Female ; Flour ; Humans ; Progesterone ; Skin

The layers of keratinocytes form an acid mantle on the surface of the skin. Herein, we investigated the effects of acidic pH on the membrane current and [Ca2+](c) of human primary keratinocytes from foreskins and human keratinocyte cell line (HaCaT). Acidic extracellular pH (pHe< or =5.5) activated outwardly rectifying Cl- current (I(Cl,pH)) with slow kinetics of voltage-dependent activation. I(Cl,pH) was potently inhibited by an anion channel blocker 4,4`-diisothiocyanostilbene-2,2`-disulphonic acid (DIDS, 73.5% inhibition at 1micrometer). I(Cl,pH) became more sensitive to pHe by raising temperature from 24degrees C to 37degrees C. HaCaT cells also expressed Ca2+ -activated Cl- current (I(Cl,Ca)), and the amplitude of I(Cl,Ca) was increased by relatively weak acidic pHe (7.0 and 6.8). Interestingly, the acidic pHe (5.0) also induced a sharp increase in the intracellular [Ca2+] (delta[Ca2+](acid)) of HaCaT cells. The delta[Ca2+](acid) was independent of extracellular Ca2+, and was abolished by the pretreatment with PLC inhibitor, U73122. In primary human keratinocytes, 5 out of 28 tested cells showed delta[Ca2+](acid). In summary, we found I(Cl,pH) and delta[Ca2+](acid) in human keratinocytes, and these ionic signals might have implication in pathophysiological responses and differentiation of epidermal keratinocytes.
Cell Line ; Estrenes ; Foreskin ; Humans ; Hydrogen-Ion Concentration ; Keratinocytes ; Kinetics ; Membranes ; Pyrrolidinones ; Skin

Animals ; Benzhydryl Compounds ; toxicity ; Biomarkers ; analysis ; blood ; Breast Neoplasms ; chemically induced ; Drug Synergism ; Endocrine Disruptors ; toxicity ; Estrone ; metabolism ; Genistein ; adverse effects ; Hydroxyestrones ; analysis ; Male ; Microsomes, Liver ; drug effects ; metabolism ; Oxidation-Reduction ; Phenols ; toxicity ; Rats, Wistar

OBJECTIVES: To determine the baseline serum concentrations of estradiol and estrone in postmenopausal Korean women and the serum concentrations of estradiol and estrone after 4 and 16 weeks of treatment using 1 mg of estradiol and 2 mg of drospirenone. METHODS: This was a multicenter study. Thirty-six subjects were screened. Serum estradiol, estrone and drospirenone levels were determined by gas chromatography-mass spectrometry and radioimmunoassay. RESULTS: The mean estradiol concentration was 8.37 +/- 12.1 pg/mL at baseline and increased to 53.7 +/- 52.1 and 41.4 +/- 26.1 pg/mL after 4 and 16 weeks of treatment, respectively. The mean estrone concentrations were 28.7 +/- 26.8, 266.1 +/- 182.9, and 256.1 +/- 179.1 pg/mL at baseline, and after 4 and 16 weeks of treatment, respectively. When women were stratified according to the basal estradiol level, the level after 4 weeks of treatment was significantly higher in the women with a detectable level (> or = 5 pg/mL) than in women with an undetectable level (< 5 pg/mL; 65.2 +/- 21.5 vs. 37.4 +/- 25.8 pg/mL, P = 0.008). After 16 weeks of treatment, the estradiol level was still higher in the detectable group (51.6 +/- 28.6 vs. 38.7 +/- 21.7 pg/mL, P = 0.09). CONCLUSION: This study showed that 1 mg of estradiol and 2 mg of drospirenone is an appropriate regimen to achieve the desired serum estradiol level. The difference in serum hormonal levels after 4 weeks of treatment could be caused by different basal levels.
Administration, Oral ; Androstenes ; Estradiol ; Estrogen Replacement Therapy ; Estrone ; Female ; Gas Chromatography-Mass Spectrometry ; Humans ; Postmenopause

The calcium-activated K+ (BKCa) channel is one of the potassium-selective ion channels that are present in the nervous and vascular systems. Ca2+ is the main regulator of BKCa channel activation. The BKCa channel contains two high affinity Ca2+ binding sites, namely, regulators of K+ conductance, RCK1 and the Ca2+ bowl. Lysophosphatidic acid (LPA, 1-radyl-2-hydroxy-sn-glycero-3-phosphate) is one of the neurolipids. LPA affects diverse cellular functions on many cell types through G protein-coupled LPA receptor subtypes. The activation of LPA receptors induces transient elevation of intracellular Ca2+ levels through diverse G proteins such as Galphaq/11, Galphai, Galpha12/13, and Galphas and the related signal transduction pathway. In the present study, we examined LPA effects on BKCa channel activity expressed in Xenopus oocytes, which are known to endogenously express the LPA receptor. Treatment with LPA induced a large outward current in a reversible and concentration-dependent manner. However, repeated treatment with LPA induced a rapid desensitization, and the LPA receptor antagonist Ki16425 blocked LPA action. LPA-mediated BKCa channel activation was also attenuated by the PLC inhibitor U-73122, IP3 inhibitor 2-APB, Ca2+ chelator BAPTA, or PKC inhibitor calphostin. In addition, mutations in RCK1 and RCK2 also attenuated LPA-mediated BKCa channel activation. The present study indicates that LPA-mediated activation of the BKCa channel is achieved through the PLC, IP3, Ca2+, and PKC pathway and that LPA-mediated activation of the BKCa channel could be one of the biological effects of LPA in the nervous and vascular systems.
Binding Sites ; Egtazic Acid ; Estrenes ; GTP-Binding Proteins ; Ion Channels ; Isoxazoles ; Lysophospholipids ; Naphthalenes ; Oocytes ; Potassium ; Potassium Channels ; Propionates ; Pyrrolidinones ; Receptors, Lysophosphatidic Acid ; Signal Transduction ; Xenopus