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Sample records for 60-hz fields estradiol

  1. Effects of 60-Hz fields, estradiol and xenoestrogens on human breast cancer cells

    SciTech Connect

    Dees, C.; Travis, C.; Garrett, S.; Henley, D.

    1996-10-01

    If exposure to xenoestrogens or electromagnetic fields (EMFs) such as 60 Hz contributes to the etiology of breast cancer, it is likely that they must stimulate the growth of breast cells, damage genetic material or enhance the effects of other mitogenic or mutagenic agents (co-promotion). Therefore, the ability of xenoestrogens or exposure to 60-Hz fields to stimulate the entry of growth-arrested human breast cancer cells into the cell cycle was determined using cyclin-dependent kinase 2 (Cdk2) activity, synthesis of cyclin D1 and cdc2 activity. Exposure of estrogen receptor-positive MCF-7 or T-47D cells to estrogen and xenoestrogens (DDT and Red No.3) increased Cdk2 and cyclin B1-cdc2 activity and cyclin D1 synthesis. Exposure of breast cancer cells to 12 mG or 1 or 9 G electromagnetic fields at 60 Hz failed to stimulate Cdk2 or cyclin B1-cdc2 activity or cyclin D1 synthesis. Simultaneous co-exposure of cells to 60-Hz fields and chemical promoters did not enhance Cdk2 activation above the levels produced by the chemical promoter alone. Estrogen and xenoestrogens also stimulated binding of the estrogen receptor to the estrogen receptor element but the EMF did not. Phorbol 12-myristate 13-acetate (PMA) induced phosphorylation of p53 and pRb105 in MCF-7 cells, but EMF exposure had no effect. DNA-damaging chemotherapeutic agents and Red Dye No. 3 were found to increase p53 site-specific DNA binding in breast cancer cells, but EMF exposure did not. These studies suggest that estrogen and xenoestrogens stimulate growth-arrested breast cancer cells to enter the growth cycle, but EMF exposure does not. Site-specific p53-DNA binding was increased in MCF-7 cells treated with DNA-damaging agents, but not by EMF exposure. EMF exposure does not appear to act as a promoter or DNA-damaging agent for human breast cancer cells in vitro. 34 refs., 10 figs.

  2. Effects of 60 Hz magnetic fields on teenagers and adults

    PubMed Central

    2013-01-01

    Background As use of electrical devices has increased, social concerns about the possible effects of 60 Hz electromagnetic fields on human health have increased. Accordingly, the number of people who complain of various symptoms such as headache and insomnia has risen. Many previous studies of the effects of extremely low frequency (ELF) magnetic field exposure on children have focused on the occurrence of childhood leukaemia and central nervous system cancers. However, very few provocation studies have examined the health effects of ELF magnetic fields on teenagers. Methods In this double-blind study, we simultaneously investigated physiological changes (heart rate, respiration rate, and heart rate variability), subjective symptoms, and magnetic field perception to determine the reliable effects of 60 Hz 12.5 μT magnetic fields on teenagers. Two volunteer groups of 30 adults and 30 teenagers were tested with exposure to sham and real magnetic fields for 32 min. Results ELF magnetic field exposure did not have any effects on the physiological parameters or eight subjective symptoms in either group. Neither group correctly perceived the magnetic fields. Conclusions Physiological data were analysed, subjective symptoms surveyed, and the percentages of those who believed they were being exposed were measured. No effects were observed in adults or teenagers resulting from 32 min of 60 Hz 12.5 μT magnetic field exposure. PMID:23705754

  3. Endocrinological effects of strong 60-Hz electric fields on rats

    SciTech Connect

    Free, M.J.; Kaune, W.T.; Phillips, R.D.; Cheng, H.C.

    1981-01-01

    Adult male rats were exposed or sham-exposed to 60-Hz electric fields without spark discharges, ozone, or significant levels or other secondary variables. No effects were discharges, ozone, or significant levels of other secondary variables. No effects were observed on body weights or plasma hormone levels after 30 days of exposure at an effective field strength of 68 kV/m. After 120 days of exposure (effective field strength = 64 kV/m), effects were inconsistent, with signficant reductions in body weight and plasma levels of follicle-stimulating hormone and corticosterone occurring in one replicate experiment but not in the other. Plasma testosterone levels were significantly reduced after 120 days of exposure in one experiment, with a similar but not statistically significant reduction in a replicate experiment. Weanling rats, exposed or sham-exposed in electric fields with an effective field strength of 80 kV/m from 20 to 56 days of age, exhibited identical or closely similar growth trends in body and organ weights. Hormone levels in exposed and sham-exposed groups were also similar. However, there was an apparent phase shift between the two groups in the cyclic variations of concentrations of hormones at different stages of development, particularly with respect to follicle-stimulating hormone and corticosterone. We concluded that 60-Hz electric fields may bring about subtle changes in the endocrine system of rats, and that these changes may be related to alterations in episodic rhythms.

  4. Influence of 60-Hz magnetic fields on sea urchin development

    SciTech Connect

    Zimmerman, S.; Zimmerman, A.M.; Winters, W.D.; Cameron, I.L. )

    1990-01-01

    Continuous exposure of sea urchin (Strongylocentrotus purpuratus) embryos at 18 degrees C to a cyclic 60-Hz magnetic field at 0.1 mT rms beginning 4 min after insemination caused a significant developmental delay during the subsequent 23 hours. No delay in development was recorded for periods up to 18 hours after fertilization. At 18 h, most embryos were in the mesenchyme blastula stage. At 23 h, most control embryos were in mid-gastrula whereas most magnetic-field-exposed embryos were in the early gastrula stage. Thus an estimated 1-h delay occurred between these developmental stages. The results are discussed in terms of possible magnetic-field modification of transcription as well as interference with cell migration during gastrulation. The present study extends and supports the growing body of information about potential effects of exposures to extremely-low-frequency (ELF) magnetic fields on developing organisms.

  5. Cardiovascular response of rats exposed to 60-Hz electric fields

    SciTech Connect

    Hilton, D.I.; Phillips, R.D.

    1980-01-01

    Recently, it has been reported that exposure to high-strength electric fields can influence electrocardiogram (ECG) patterns, heart rates, and blood pressures in various species of animals. Our studies were designed to evaluate these reported effects and to help clarify some of the disagreement present in the literature. Various cardiovascular variables were measured in Sprague-Dawley rats exposed or sham-exposed to 60-Hz electric fields at 80 to 100 kV/m for periods up to four months. No significant differences in heart rates, ECG patterns, blood pressures, or vascular reactivity were observed between exposed and sham-exposed rats after 8 hours, 40 hours, 1 month, or 4 months of exposure. Our studies cannot be directly compared to the work of other investigators because of differences in animal species and electric-field characteristics. However, our failure to detect any cardiovascular changes may have been the result of (1) eliminating secondary field effects such as shocks, audible noise, corona, and ozone; (2) minimizing steady-state microcurrents between the mouth of the animal and watering devices; and (3) minimizing electric-field-induced vibration of the electrodes and animal cages.

  6. Detection thresholds for 60 Hz electric fields by nonhuman primates

    SciTech Connect

    Orr, J.L.; Rogers, W.R.; Smith, H.D.

    1995-12-31

    Because responses of animals to detection of the presence of an electric field (EF) are a possible mechanism for production of biological effects, it is important to know what EF intensities are detectable. Operant methods were used to train six baboons (Papio cynocephalus) to perform a psychophysical task involving detection of EF presence. During the response phase of a trial, a subject responded on one push button to report the presence of the EF and on a different push button to report the absence of the EF. Correct reports of EF presence or absence produced delivery of food rewards. The subjects became proficient at performing this psychophysical detection task; during 35 days of testing, false alarm rates averaged 9%. The average EF detection threshold was 12 kV/m; the range of means among subjects was 5--15 kV/m. Two special test procedures confirmed that the subjects were responding directly to EF presence or absence and not to artifacts that might be associated with EF generation. The EF detection threshold of nonhuman primates is similar to thresholds reported for rats and humans.

  7. Effects of 60 Hz electric fields on operant and social stress behaviors of nonhuman primates

    SciTech Connect

    Rogers, W.R.; Lucas, J.H.; Moore, G.T.; Orr, J.L.

    1985-01-01

    An overall description of this research program is presented. The objectives are to investigate using nonhuman primates, possible behavioral effects associated with exposure to high-intensity, 60 Hz, electric fields. 6 tabs.

  8. Retardation of embryogenesis by extremely low frequency 60 Hz electromagnetic fields.

    PubMed

    Cameron, I L; Hunter, K E; Winters, W D

    1985-01-01

    Fertilized Medaka fish eggs were used to determine if electromagnetic fields, designed to simulate those beneath a high voltage power line, have biological effects on vertebrate embryo development. The newly fertilized eggs were exposed to a 60 Hz electrical field of 300 mA/m2 current density, a 60 Hz magnetic field of 1.0 gauss RMS, or to the combined electric plus magnetic fields for 48 hours. No gross abnormalities were observed in any of the embryos as they developed, but significant development delays were seen in those embryos exposed to either the magnetic or to the combined electromagnetic fields; delays were not seen in the embryos exposed to the electrical field. Thus, a 60 Hz magnetic field like that encountered in a man made powerline environment was shown to retard development of fish embryos.

  9. Brown-colored deposits on hair of female rats chronically exposed to 60-Hz electric fields

    SciTech Connect

    Leung, F.C.; Rommereim, D.N.; Miller, R.A.; Anderson, L.E. )

    1990-01-01

    An increased incidence and severity of a brownish coloration of hair has been observed around the nose and on the ears of female rats that were chronically exposed to 60-Hz electric fields. Microscopic examination of the colored areas revealed a red-brown globular deposit on hair shafts in affected areas without signs of physical injury.

  10. Effects of 60-Hz electric fields on embryo and chick development, growth, and behavior. Final report

    SciTech Connect

    Not Available

    1985-07-01

    The objective of this study was to utilize an avian model to determine the effects of 60-Hz electric fields on embryo and chick development. A specially designed incubator allowed simultaneous incubation of control eggs and eggs exposed to 60-Hz electric fields. Two series of experimental voltages were utilized for this study. In Series 1, the subject eggs were exposed to 20, 40, 60, 80, and 100 kV/m fields and, in Series 2, eggs were exposed to 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, and 100 kV/m. Data were collected on mortality, malformation, and growth (weight) of 7- and 14-day-old embryos after continuous exposure to electric fields. Eggs were also incubated, exposed to electric fields, and hatched in order to collect data on chick weights at one day and at 2, 4, and 6 weeks after hatching. Behavior tests on newly hatched chicks that had been exposed to electric fields during development were also performed. The results indicated no consistent effect of 60-Hz electric fields, varying from 0.1 to 100 kV/m, on mortality, malformations, weights, bone growth (metatarsal length), or behavior of embryos or chicks. This study strongly suggests that within the scope of this project, there is no consistent direct effect of 60 Hz electric fields on the health and well-being of avian embryos. A dose-response analysis was also utilized in which all the data in each series, for each age of the embryos, were simultaneously evaluated in a statistical model. This analysis demonstrated that there is no significant dose-response of electric fields on 7- and 14-day-old embryo and 1-day-old chick weights. 24 refs., 21 figs., 56 tabs.

  11. Development toxicology study in rats exposed to 60-Hz horizontal magnetic fields. Final report

    SciTech Connect

    Anderson, L.E.

    1997-09-01

    A replicate study using large numbers of animals was conducted to determine if 60 Hz magnetic fields would produce developmental toxicity in rats. Systems used previously for electric field exposures were retrofitted to provide magnetic field exposures to small laboratory animals. Large coils, separated from the rat cages, were energized by computer-controlled function generators providing a relatively pure, 1,000--{micro}T (10 G), 60-Hz, horizontal magnetic field for the high exposure group. Leakage fields to a second system provided a second exposure group with average exposures of 0.61 {micro}T (6.1 mG). Ambient fields within a third (control) system were 0.09 {micro}T (0.9 mG). Replicate experiments were conducted in which female rats were mated, and sperm-positive females were randomly distributed among the three exposure groups: (0.09, 0.61, and 1,000 {micro}T). Pregnant animals were exposed to 60 Hz horizontal magnetic fields for 20 hr/day from mating until very near term, 20 days later.

  12. Effects of 60 Hz electric fields on operant and social stress behaviors of nonhuman primates

    SciTech Connect

    Rogers, W.R.; Coelho, A.M. Jr.; Easley, S.P.; Lucas, J.H.; Moore, G.T.; Orr, J.L.; Smith, H.D.; Taylor, L.L.; Tuttle, M.L.

    1987-10-24

    The objective of this program is to investigate, using the baboon as a nonhuman primate surrogate for the human, possible behavioral effects associated with exposure to high intensity 60 Hz electric fields. Results from this program, along with information from experiments conducted elsewhere, will be used by the Department of Energy (DOE) to estimate and evaluate the likelihood of deleterious consequences resulting from exposure of humans to the electric fields associated with power transmission over high voltage lines. This research program consists of four major research projects, all of which have been successfully completed. The first project evaluated the potentially aversive character of exposure to 60 Hz electric fields by determining the threshold intensity that produces escape or avoidance responses. The second project estimated the threshold intensity for detection threshold was 12 kV/m; the range of means was 6 to 16 kV/m. The third project assessed, in separate experiments conducted at 30 and 60 kV/m, effects of chronic exposure to electric fields on the performance of two operant conditioning tasks, fixed ratio (FR), and differential reinforcement of low rate (DRL). In the same two experiments, the fourth project investigated, using the systematic quantitative observational sampling methods of primatology, the possible stress-inducing effects of chronic exposure to 60 Hz electric fields on the behavior of baboons living in small social groups. 131 refs., 87 figs., 123 tabs.

  13. Effects of 60-Hz electric fields on specific humoral and cellular components of the immune system

    SciTech Connect

    Morris, J.E.; Phillips, R.D.

    1982-01-01

    Humoral and cellular functions of the immune system of Swiss-Webster mice were evaluated after exposure to 60-Hz electric fields at 100 kV/m. No significant differences were observed in primary antibody response to keyhole limpet hemocyanin (precipitating antibody levels) between exposed (30 or 60 days) and control mice, nor were there significant changes in mitogen-stimulation response of spleen cells from mice similarly exposed for 90 or 150 days when compared to sham-exposed animals.

  14. Comparison of cardiac and 60 Hz magnetically induced electric fields measured in anesthetized rats

    SciTech Connect

    Miller, D.L.; Creim, J.A.

    1997-06-01

    Extremely low frequency magnetic fields interact with an animal by inducing internal electric fields, which are in addition to the normal endogenous fields present in living animals. Male rats weighing about 560 g each were anesthetized with ketamine and xylazine. Small incisions were made in the ventral body wall at the chest and upper abdomen to position a miniature probe for measuring internal electric fields. The calibration constant for the probe size was 5.7 mm, with a flat response from at least 12 Hz to 20 kHz. A cardiac signal, similar to the normal electrocardiogram with a heart rate of about 250 bpm, was readily obtained at the chest. Upon analysis of its spectrum, the cardiac field detected by the probe had a broad maximum at 32--95 Hz. When the rates were exposed to a 1 mT, 60 Hz magnetic field, a spike appeared in the spectrum at 60 Hz. The peak-to-peak magnitudes of electric fields associated with normal heart function were comparable to fields induced by a 1 mT magnetic field at 60 Hz for those positions measured on the body surface. Within the body, or in different directions relative to the applied field, the induced fields were reduced. The cardiac field increased near the heart, becoming much larger than the induced field. Thus, the cardiac electric field, together with the other endogenous fields, combine with induced electric fields and help to provide reference levels for the induced-field dosimetry of ELF magnetic field exposures of living animals.

  15. Immunological and biochemical effects of 60 Hz electric and magnetic fields in humans

    SciTech Connect

    Fotopoulos, S.S.; Graham, C.

    1990-01-01

    Demand for electric energy increased at an annual average rate of 7.5% between 1912 and 1971. In order to meet this demand, utility companies have increased the number and size of their generating units and the operating voltages employed in overhead transmission lines. Recently public concern has been expressed about possible risks to human health, function, and well-being arising from exposure to the electric and magnetic fields associated with overhead transmission line voltage. The Department of Energy funded the present project to investigate the effects of 60-Hz electric and magnetic fields on critically important immunological, biochemical, and hematological variables. Inclusion of such variables will be of great value in assessing the effects of 60-Hz fields on human health and welfare, and will provide results comparable to ongoing animal studies. The scope of this project includes six major goals: development of systems for incorporating biochemistry, hematology, and immunology data collection into the procedures already developed for the performance and physiology study funded by the New York State Overhead Power Lines Project; development of sample tracking and quality assurance procedures for project data; methods development and setting up of all procedures for performing assays; collecting data; carrying out assays according to the procedures defined; and statistically evaluating and interpreting the effects of 60-Hz exposure on hematological, biochemical, and immunological parameters. 3 tabs.

  16. 60-Hz electric-field effects on pineal melatonin rhythms: time course for onset and recovery

    SciTech Connect

    Wilson, B.W.; Chess, E.K.; Anderson, L.E.

    1986-01-01

    Rats exposed for 3 weeks to uniform 60-Hz electric fields of 39 kV/m (effective field strength) failed to show normal pineal gland circadian rhythms in serotonin N-acetyl transferase activity and melatonin concentrations. The time required for recovery of the melatonin rhythm after cessation of field exposure was determined to be less than 3 days. The rapid recovery suggests that the overall metabolic competence of the pineal is not permanently compromised by electric-field exposure, and that the circadian rhythm effect may be neuronally mediated.

  17. Behavioral studies with mice exposed to DC and 60-Hz magnetic fields

    SciTech Connect

    Davis, H.P.; Mizumori, S.J.Y.; Allen, H.; Rosenzweig, M.R.; Bennett, E.L.; Tenforde, T.S.

    1984-01-01

    Behavioral measures were evaluated in adult CD-1 and LAF-1 mice continuously exposed for 72 h to a 1.5-Tesla (1 T = 10/sup 4/ Gauss) homogeneous DC magnetic field, and in LAF-1 mice continuously exposed for 72 h to a sinusoidal 60-Hz, 1.65-mT (rms) homogeneous AC field. Three types of behavioral tests were employed: (1) memory of an electroshock-motivated passive avoidance task was assessed in animals that had been trained immediately prior to the field exposure. The strength of memory was varied either by altering the strength of the electric footshock during training, or by administering a cerebral protein synthesis inhibitor, anisomycin, at the time of training. (2) General locomotor activity was measured using a quadrant-crossing test immediately after termination of the magnetic field exposure. (3) Sensitivity of the experimental subjects to the seizure-inducing neuropharmacological agent, pentylenetetrazole, was assessed immediately after the field exposure on the basis of three criteria: (a) the percentage of subjects exhibiting a generalized seizure, (b) the mean time to seizure, and (c) the mean seizure level. The results of these studies revealed no behavior alterations in exposed mice relative to controls in any of the experimental tests with the 1.5-T DC field or the 60-Hz, 1.65-mT (rms) AC field. 57 references, 6 figures, 1 table.

  18. Relationship between field strength and arousal response in mice exposed to 60-Hz electric fields

    SciTech Connect

    Rosenberg, R.S.; Duffy, P.H.; Sacher, G.A.; Ehret, C.F.

    1983-01-01

    White-footed mice, Peromyscus leucopus, were exposed to 60-Hz electric fields to study the relationship between field strength and three measures of the transient arousal response previously reported to occur with exposures at 100 kV/m. Five groups of 12 mice each were given a series of four 1-h exposures, separated by an hour, with each group exposed at one of the following field strengths: 75, 50, 35, 25, and 10 kV/m; 8 additional mice were sham-exposed with no voltage applied to the field generator. All mice were experimentally naive before the start of the experiment, and all exposures occurred during the inactive (lights-on) phase of the circadian cycle. The first exposure produced immediate increases in arousal measures, but subsequent exposures had no significant effect on any measure. These arousal responses were defined by significant increases of gross motor activity, carbon dioxide production, and oxygen consumption, and were frequently recorded with field strengths of 50 kV/m or higher. Significant arousal responses rarely occurred with exposures at lower field strengths. Responses of mice exposed at 75 and 50 kV/m were similar to previously described transient arousal responses in mice exposed to 100-kV/m electric fields. Less than half of the mice in each of the field strength groups below 50 kV/m showed arousal response based on Z (standard) scores, but the arousals of the mice that did respond were similar to those of mice exposed at higher field strengths. Polynomial regression was used to calculate the field strength producing the greatest increases for each of the arousal measures. The results show that the amplitude of the transient arousal response is related to the strength of the electric field, but different measures of arousal may have different relationships to field strength.

  19. Diurnal patterns in brain biogenic amines of rats exposed to 60-Hz electric fields

    SciTech Connect

    Vasquez, B.J.; Anderson, L.E.; Lowery, C.I.; Adey, W.R.

    1988-01-01

    Levels of brain neurotransmitters and their metabolites, as well as concentrations of enzymes associated with their synthesis and metabolism, fluctuate during the day in patterns defined as circadian. The present study examined these rhythms in albino rats exposed to 60-Hz electric fields. Thirty-six animals were exposed to a 39 kV/m field for 4 weeks, 20 h/day, in a parallel-plate electrode system. A group of 36 sham animals was similarly handled and housed in a nonenergized exposure system. On the sampling day, animals were sacrificed at 4-h intervals throughout the 24-h day. Brains were removed, dissected, and kept frozen until chemically analyzed. The levels of biogenic amines and their acidic metabolites in the striatum, hypothalamus, and hippocampus were determined by high-performance liquid chromatography with electrochemical detection (HPLC-ECD) methods. Repeated exposure to 60-Hz electric fields produced significant alterations in the diurnal rhythms of several biogenic amines: dihydroxyphenylacetic acid (DOPAC, the primary metabolite of dopamine in the rat) in the striatum, and norepinephrine, dopamine, and 5-hydroxyindoleacetic acid (5-HIAA; serotonin metabolite) in the hypothalamus. Levels of serotonin in the striatum and hypothalamus showed clear circadian patterns that was not affected by the field. No diurnal or field-related changes were observed in the hippocampal amines.

  20. Cytohistological analysis of roots whose growth is affected by a 60-Hz electric field

    SciTech Connect

    Brulfert, A.; Miller, M.W.; Robertson, D.; Dooley, D.A.; Economou, P.

    1985-01-01

    Roots of Pisum sativum were exposed for 48 h to 60-Hz electric fields of 430 V/m in an aqueous inorganic growth medium. The growth in length of the exposed roots was 44% of that for control roots. Root tips were analyzed for mitotic index and cell cycle duration. Mature, differentiated root sections from tissue produced after electrode energization were analyzed for cell lengths and number of files. The major reason for the observation that exposed roots are shorter than control roots is that cell elongation in the former is greatly diminished relative to controls. 15 references, 1 figures, 4 tables.

  1. Attempts to produce taste-aversion learning in rats exposed to 60-Hz electric fields

    SciTech Connect

    Creim, J.A.; Lovely, R.H.; Kaune, W.T.; Phillips, R.D.

    1984-01-01

    A measure of taste-aversion (TA) learning was used in three experiments to 1) determine whether exposure to intense 60-Hz electric fields can produce TA learning in male Sprague-Dawley rats, and (2) establish a dose-response function for the behavior in question. In Experiment 1, four groups of eight rats each were distributed into one of two exposures (69 +/- 5 kV/m or 133 +/- 10 kV/m) or into one of two sham-exposure groups. Conditioning trials paired 0.1% sodium saccharin in water with 3 h of exposure to a 60-Hz electric field. Following five conditioning trials, a 20-min, two-bottle preference test between water and saccharin-flavored water failed to reveal TA conditioning in exposed groups. In Experiment 2, four groups of eight rats each (34 +/- 2 kV/m or 133 +/- 10 kV/m and two sham-exposed groups) were treated as before. Electric-field exposure had no effect on TA learning. Experiment 3 tested for a possible synergy between a minimal dose (for TA learning) of cyclophosphamide (6 mg/kg) and 5 h of exposure to 133 +/- 10 kV/m electric fields in a dark environment under conditions otherwise similar to those of Experiments 1 and 2. The results indicated no TA learning as reflected in the relative consumption of saccharin. 16 references, 6 figures, 1 table.

  2. Large granular lymphocytic (LGL) leukemia in rats exposed to intermittent 60 Hz magnetic fields.

    PubMed

    Anderson, L E; Morris, J E; Miller, D L; Rafferty, C N; Ebi, K L; Sasser, L B

    2001-04-01

    An animal model for large granular lymphocytic (LGL) leukemia in male Fischer 344 rats was utilized to determine whether magnetic field exposure can be shown to influence the progression of leukemia. We previously reported that exposure to continuous 60 Hz, 1 mT magnetic fields did not significantly alter the clinical progression of LGL leukemia in young male rats following injection of spleen cells from donor leukemic rats. Results presented here extend those studies with the following objectives: (a) to replicate the previous study of continuous 60 Hz magnetic field exposures, but using fewer LGL cells in the inoculum, and (b) to determine if intermittent 60 Hz magnetic fields can alter the clinical progression of leukemia. Rats were randomly assigned to four treatment groups (18/group) as follows: (1) 1 mT (10 G) continuous field, (2) 1 mT intermittent field (off/on at 3 min intervals), (3) ambient controls ( < 0.1 microT), and (4) positive control (5 Gy whole body irradiation from cobalt-60 four days prior to initiation of exposure). All rats were injected intraperitoneally with 2.2 x 10(6) fresh, viable LGL leukemic spleen cells at the beginning of the study. The fields were activated for 20 h per day, 7 days per week, and all exposure conditions were superimposed over the natural ambient magnetic field. The rats were weighed and palpated for splenomegaly weekly. Splenomegaly developed 9-11 weeks after transplantation of the leukemia cells. Hematological evaluations were performed at 6, 8, 10, 12, 14, and 16 weeks of exposure. Peripheral blood hemoglobin concentration, red blood cells, and packed cell volume declined, and total white blood cells and LGL cells increased dramatically in all treatment groups after onset of leukemia. Although the positive control group showed different body weight curves and developed signs of leukemia earlier than other groups, differences were not detected between exposure groups and ambient controls. Furthermore, there were no

  3. Effects of a 60 Hz magnetic field on central cholinergic systems of the rat

    SciTech Connect

    Lai, H.; Carino, M.A.; Horita, A.; Guy, A.W. )

    1993-03-15

    The authors studied the effects of an acute exposure to a 60 Hz magnetic field on sodium-dependent, high-affinity choline uptake in the brain of the rat. Decreases in uptake were observed in the frontal cortex and hippocampus after the animals were exposed to a magnetic field at flux densities [>=] 0.75 mT. These effects of the magnetic field were blocked by pretreating the animals with the narcotic antagonist naltrexone, but not by the peripheral opioid antagonist, naloxone methiodide. These data indicate that the magnetic-field-induced decreases in high-affinity choline uptake in the rat brain were mediated by endogenous opioids in the central nervous systems.

  4. Chronic exposure to a 60-Hz electric field: effects on neuromuscular function in the rat

    SciTech Connect

    Jaffe, R.A.; Laszewski, B.L.; Carr, D.B.

    1981-01-01

    Neuromuscular function in adult male rats was studied following 30 days of exposure to a 60-Hz electric field at 100 kV/m (unperturbed field strength). Isometric force transducters were attached to the tendons of the plantaris (predominantly fast twitch), and soleus (predominantly slow twitch) muscles in the urethan-anesthetized rat. Square-wave stimuli were delivered to the distal stump of the transected sciatic nerve. Several measurements were used to characterize neuromuscular function, including twitch characteristics, chronaxie, tetanic and posttetanic potentiation, and fatigue and recovery. The results from three independent series of experiments are reported. Only recovery from fatigue in slow-twitch muscles was consistently and significantly affected (enhanced) by electric-field exposure. This effect does not appear to be mediated by field-induced changes in either neuromuscular transmission, or in the contractile mechanism itself. It is suggested that the effect may be mediated secondary to an effect on mechanisms regulating muscle blood flow or metabolism.

  5. Chronic exposure to a 60-Hz electric field: effects on neuromuscular function in the rat.

    PubMed

    Jaffe, R A; Laszewski, B L; Carr, D B

    1981-01-01

    Neuromuscular function in adult male rats was studied following 30 days of exposure to a 60-Hz electric field at 100 kV/m (unperturbed field strength). Isometric force transducers were attached to the tendons of the plantaris (predominantly fast twitch), and soleus (predominantly slow twitch) muscles in the urethan-anesthetized rat. Square-wave stimuli were delivered to the distal stump of the transected sciatic nerve. Several measurements were used to characterized neuromuscular function, including twitch characteristics, chronaxie, tetanic and posttetanic potentiation, and fatigue and recovery. The results from three independent series of experiments are reported. Only recovery from fatigue in slow-twitch muscles was consistently and significantly affected (enhanced) by electric-field exposure. This effect does not appear to be mediated by field-induced changes in either neuromuscular transmission, or in the contractile mechanism itself. It is suggested that the effect may be mediated secondary to an effect on mechanisms regulating muscle blood flow or metabolism.

  6. Effect of chronic 60-Hz electric field exposure on mammary tumorigenesis in the rat

    SciTech Connect

    Anderson, L.E.; Leung, F.C.; Rommereim, D.N.; Buschbom, R.L.; Wilson, B.W.; Stevens, R.G.

    1989-07-01

    Female rats were administered a single dosage of 7 or 10 mg of DMBA intragastrically between 50 and 55 days of age and palpated weekly for mammary tumors in two experiments. Rats were either exposed to a 40 kV/m 60-Hz electric field or sham-exposed in utero through 18 or 23 weeks of age. There was no difference between electric field exposed and sham-exposed in incidence of first tumor. When the results of the two experiments were combined, the electric field exposed groups had significantly more tumors per tumor-bearing animal than the sham-groups. These results may have implications for the role of electric power use in the etiology and promotion of breast cancer. 21 refs., 1 fig., 1 tab.

  7. Entamoeba invadens: influence of 60 Hz magnetic fields on growth and differentiation.

    PubMed

    Rodríguez-De la Fuente, Abraham O; Heredia-Rojas, J Antonio; Mata-Cárdenas, Benito David; Vargas-Villarreal, Javier; Rodríguez-Flores, Laura E; Balderas-Candanosa, Isaías; Alcocer-González, Juan M

    2008-06-01

    Exposure to extremely low-frequency (ELF) electromagnetic fields appears to result in a number of important biological changes. In the present study, we evaluated the effects of 60 Hz sinusoidal magnetic fields (MF) at magnetic flux densities of 1.0, 1.5 and 2.0 mT on growth and differentiation of the protozoan Entamoeba invadens. We demonstrated an inhibitory growth effect when trophozoite cultures were exposed to 1.5 and 2.0 mT. Furthermore, we found that there was not a synergistic effect in cultures co-exposed to MF and Metronidazole, a cytotoxic drug against amoebic cells. In addition, MF exposure inhibited the encystation process of E. invadens.

  8. Effects of 60 Hz electrical fields on operant and social stress behaviors of nonhuman primates: Summary

    SciTech Connect

    Rogers, W.R.; Coelho, A.M. Jr.; Easley, S.P.; Orr, J.L.

    1988-04-06

    The objective of this program is to investigate, using the baboon as a nonhuman primate surrogate for the human, behavioral effects associated with exposure to 60-Hz electric fields. Results from this program, along with information from experiments conducted elsewhere, could be used to estimate and evaluate the likelihood of deleterious consequences resulting from exposure of humans to the electric fields associated with power transmission over high voltage lines. This program is being conducted at Southwest Research Institute as part of an international collaborative information exchange and scientific research effort involving the United State Department of Energy, Japan's Ministry of International Trade and Industry, and Japan's Central Research Institute of the Electric Power Industry. Since August of 1984, four major research projects were successfully completed. 48 refs., 12 figs., 2 tabs.

  9. A 0.5 G, 60 Hz magnetic field suppresses melatonin production in pinealocytes.

    PubMed

    Rosen, L A; Barber, I; Lyle, D B

    1998-01-01

    The objective of this study was to develop a model for testing various hypotheses concerning possible mechanisms whereby electromagnetic fields might induce suppression of nighttime melatonin production in rodents. A published method for digesting freshly obtained pineal glands to the single cell level was modified, yielding better than 95% viability. An in vitro exposure facility developed for the Food and Drug Administration was used for 12-h overnight exposures of primary pinealocyte cultures to 0.05 mT, 60 Hz, vertical AC and 0.06 microT, DC fields. After exposure, cells were separated from the supernatant by centrifugation. Supernatant melatonin was measured by ELISA assays. Data from 10 experiments demonstrated an average 46% reduction in norepinephrine-induced production of melatonin in the pinealocytes. The results support the hypothesis that EM exposure can produce pineal gland melatonin suppression by affecting individual cells.

  10. Chronic exposure to 60-Hz electric fields: effects on pineal function in the rat

    SciTech Connect

    Wilson, B.W.; Anderson, L.E.; Hilton, D.I.; Philips, R.D.

    1980-01-01

    As a component of studies to search for effects of 60-Hz electric field exposure on mammalian endocrine function, concentrations of melatonin, 5-methoxytryptophol, and serotonin-N-acetyl transferase activity were measured in the pineal glands of rats exposed or sham-exposed at 65 kV/m for 30 days.In two replicate experiments there were statistically significant differences between exposed and control rats in that the normal nocturnal increase in pineal melatonin content was depressed in the exposed animals. Concentrations of 5-methoxytryptophol were increased in the pineal glands of the exposed groups when compared to sham-exposed controls. An alteration was also observed in serotonin-N-acetyl transferase activity, with lower levels measured in pineal glands from exposed animals.

  11. Biological studies of swine exposed to 60-Hz electric fields. Volume 2: Behavior. Final report

    SciTech Connect

    Not Available

    1985-12-01

    The behavioral responses in three generations of miniature swine chronically exposed to a 30-kV/m, 60-Hz electric field have been assessed in a series of screening experiments. Tests were conducted on mature swine as well as on very young swine and weanlings and included measures of: (1) preference for exposure to or shielding from the electric field; (2) early neuromuscular development; (3) exploratory behavior; (4) simple learning and memory function; and (5) short-term memory. Repeated evaluations of behavioral parameters show few statistically significant effects. In the parental (F/sub 0/) generation, exposed sows showed a preference to remain out of the field, particularly during the dark period. Adult first-generation (F/sub 1/) sows, however, failed to demonstrate such a preference to stay out of the field. In other behavioral assessments, the singular significant effect in F/sub 1/ swine was the increased number of vocalizations in both male and female swine during the exploratory behavior test. This result, also inconsistent across generations, was not repeated in the second-generation (F/sub 2/) exploratory tests, where exposed female swine made significantly fewer vocalizations than their sham-exposed counterparts. The study provides no other evidence of an overall behavioral effect in swine of prenatal exposure to electric fields. 13 refs., 5 figs., 11 tabs.

  12. Biological effects of 60-Hz electric fields on small and large laboratory animals

    SciTech Connect

    Phillips, R.D.

    1981-01-01

    Rats and mice were exposed to 60-Hz electric fields up to 330 kV/m for durations as long as four months. No significant effects were found in the following major areas: metabolic status and growth; organ and tissue morphology; brain morphology; cardiovascular function; serum chemistry; reproduction; prenatal growth and development; teratology; bone growth; peripheral nerve function; humoral and cell-mediated immunity; susceptibility to viral infection; cell and membrane function; illness/malaise; and cytogenetics. Statistically significant effects of electric field exposures were observed in the following areas: bone fracture repair; neonatal development; neuromuscular function; endocrinology; hematology; neurochemistry; urine volume and chemistry; sympathetic nervous system; behavior. It is likely that many of the effects observed are secondary to chronic stimulation of the animal by the field. Our research efforts have shifted to an in-depth investigation of nervous system functions, with emphasis in behavior, neurochemistry, neurophysiology, and dosimetry. Current and future research in these areas will focus on: relationship of effects to field strength and duration of exposure; recovery from observed effects; fundamental understanding of observed effects; fundamental understanding of interaction of field with animal (dosimetry); and biological significance of observed effects. (ERB)

  13. Effects of 60-Hz electric fields on cellular elongation and radial expansion growth in cucurbit roots.

    PubMed

    Brayman, A A; Miller, M W; Cox, C

    1987-01-01

    Serial longitudinal and transverse sections were prepared from roots of Cucumis sativus and Cucurbita maxima that had been exposed/sham-exposed to 60-Hz electric fields for 0-2 days. Field exposures were selected to produce a 10-20% or a 70-80% growth inhibition in whole roots of both species. Cortical cell length and diameter were measured using a microscope and eyepiece micrometer; measurements were conducted "blind." In both species, inhibition of cellular elongation was associated with exposure to electric fields (EF). Cellular radial expansion was apparently unaffected by exposure to electric fields. The diameters of radially unexpanded or fully expanded C. sativus cortical cells were about 25-30% smaller than those of comparable cells in C. maxima roots. Previous studies of the relationship between rates of root growth and applied EF strength showed that the response thresholds of C. sativus and C. maxima differed by a similar relative amount. These results are consistent with the postulate that EF-induced effects in roots are elicited by induced transmembrane potentials.

  14. Effects of 60-Hz electric fields on serotonin metabolism in the rat pineal gland

    SciTech Connect

    Anderson, L.E.; Hilton, D.I.; Phillips, R.D.; Wilson, B.W.; Chess, E.K.

    1982-06-01

    Serotonin and two of its metabolites, melatonin and 5-methoxytryptophol, exhibit circadian rhythmicity in the pineal gland. We recently reported a marked reduction in the normal night-time increase in melatonin concentration in the pineal glands of rats exposed to 60-Hz electric fields. Concomitant with the apparent abolition of melatonin rhythmicity, serotonin-N-acetyl transferase (SNAT) activity was suppressed. We have now conducted studies to determine if abolition of the rhythm in melatonin production in electric-field-exposed rats arises solely from interference in SNAT activity, or if the availability of pineal serotonin is a factor that is affected by exposure. Pineal serotonin concentrations were compared in rats that were either exposed or sham exposed to 65 kV/m for 30 days. Sham-exposed animals exhibited normal diurnal rhythmicity for pineal concentrations of both melatonin and serotonin; melatonin levels increased markedly during the dark phase with a concurrent decrease in serotonin levels. In the exposed animals, however, normal serotonin rhythmicity was abolished; serotonin levels in these animals did not increase during the light period. The conclusion that electric field exposure results in a biochemical alteration in SNAT enzyme activity can be inferred from the loss of both serotonin and melatonin rhythmicity, as well as by direct measurement of SNAT activity itself. 35 references, 3 figures, 1 table.

  15. Biophoton emission of MDCK cell with hydrogen peroxide and 60 Hz AC magnetic field.

    PubMed

    Cheun, B S; Yi, S H; Baik, K Y; Lim, J K; Yoo, J S; Shin, H W; soh, K S

    2007-10-01

    We studied biophoton characteristics of Madin-Darby canine kidney (MDCK) cells under the influence of H2O2 by employing a photomultiplier tube (PMT) and a fluorescence microscope. H2O2 was used for producing reactive oxygen species (ROS) in the measurement. Images from a fluorescence microscope show an increase of photon intensity emitted from the sample due to H2O2. By using a PMT we measured quantitative change in biophoton emission with application of H2O2 to the MDCK cell culture, found that the increase of the biophoton is dependent upon the amount of H2O2. The agreement between the results of the PMT and the fluorescence microscope suggests the possibility of quantitative measurement of the influence of ROS on living tissue or cell. In addition we applied a 60 HzAC magnetic field on the cells to investigate the change in reaction between MDCK cell and ROS. It showed that a decay of chemiluminescence intensity has taken a different path following exposure to the magnetic field. As a result, the PMT measurement might be considered as a useful tool for studying biochemical characteristics in relation to ROS.

  16. Vacuum pumping properties of a high voltage 60 Hz crossed field discharge

    NASA Astrophysics Data System (ADS)

    Ames, E. E.

    The principle of electron trapping in a.d.c. Penning discharge is used in the design of standard vacuum pumping equipment. The feasibility of achieving vacuum pumping using high 60 Hz a.c. voltages and permanent magnets arranged to form a crossed field configuration is investigated here. The applications are to use the voltages inherently available in high voltage vacuum insulated power apparatus to cause a vacuum pumping action. This would create a self maintained vacuum without employing an auxiliary vacuum pump. The objective is to maintain a vacuum in the face of outgassing in systems of large surface area over long periods of time, and not necessarily to obtain a fast pump down of the system. Vacuum insulation of underground power cables would require pumps to maintain the vacuum while the cable remains underground for long periods of time. Other applications are in vacuum circuit breaker, lightning arrester, and surge arrester designs. Two devices were designed, built and tested which utilize high 6 Hz a.c. voltages and permanent magnets to generate a crossed field discharge.

  17. Inhibitory effects of powerline-frequency (60-Hz) magnetic fields on pentylenetetrazol-induced seizures and mortality in rats.

    PubMed

    Ossenkopp, K P; Cain, D P

    1991-08-29

    The possibility that exposure to powerline frequency (60-Hz) magnetic fields might affect the form or intensity of epileptic seizures, induced by administration of pentylenetetrazol (PTZ) in rats, was examined. Male adult rats were exposed to either 60-Hz magnetic fields with intensities of up to 1.85 gauss (185 microT) or to a sham field condition, for 1 h prior to injections of PTZ (45-75 mg/kg). The subsequent seizures were monitored and recorded on videotape and any subsequent mortalities were noted. Exposure to 60-Hz magnetic fields prior to administration of PTZ was found to significantly (P less than 0.005) reduce the lethality of the drug-induced seizures. The LD50 for the sham-exposed group was 65.88 mg/kg, whereas for the 60-Hz magnetic field-exposed rats, the LD50 was 85.33 mg/kg. In some experiments exposure to the 1.0 and 1.5 gauss magnetic fields also produced significant (P less than 0.05) reductions in seizure durations. These findings suggest that acute exposure to low intensity 60-Hz magnetic fields has an inhibitory effect on the lethality and expression of PTZ-induced seizures in rats. Some possible mechanisms, which could account for these observed effects of magnetic field exposure on seizures, are discussed.

  18. Studies on prenatal and postnatal development in rats exposed to 60-Hz electric fields

    SciTech Connect

    Sikov, M.R.; Montgomery, L.D.; Smith, L.G.; Phillips, R.D.

    1984-01-01

    A series of three experiments was performed to determine the effects of 30-day exposures to uniform 60-Hz electric fields (100 kV/m) on reproduction and on growth and development in the fetuses and offspring of rats. In the first experiment, exposure of females for 6 days prior to and during the mating period did not affect their reproductive performance, and continued exposure through 20 days of gestation (dg) did not affect the viability, size, or morphology of their fetuses. In the second experiment, exposure of the pregnant rat was begun on 0 dg and continued until the resulting offspring reached 8 days of age. In the third experiment, exposure began at 17 dg and continued through 25 days of postnatal life. In the second and third experiments, no statistically significant differences suggesting impairment of the growth or survival of exposed offspring were detected. In the second experiment, a significantly greater percentage of the exposed offspring showed movement, standing, and grooming at 14 days of age than among-sham-exposed offspring. There was a significant decrease at 14 days in the percentage of exposed offspring displaying the righting reflex in the second experiment and negative geotropism in the third experiment. These differences were all transient and were not found when the animals were tested again at 21 days of age. Evaluation of the reproductive integrity of the offspring of the second experiment did not disclose any deficits.

  19. Nonhuman primates will not respond to turn off strong 60 Hz electric fields

    SciTech Connect

    Rogers, W.R.; Orr, J.L.; Smith, H.D.

    1995-12-31

    Using a set of six baboons (Papio cynocephalus), the authors conducted a series of seven experiments designed to evaluate the potentially aversive character of a 60 Hz electric field (EF). Initially, the subjects were trained, using food rewards as the reinforcer, to respond only when a cue light was illuminated. Next, an EF was presented along with the cue light; responses produced delivery of a food pellet and turned off both the cue light and the EF. Then, stimulus and reward conditions were varied. The authors determined that (1) presence of a strong EF does not affect operant responding for food rewards, (2) subjects will not respond at normal rates when the only reinforcer is termination of a strong EF, (3) presence of a strong EF can serve as a discriminative stimulus, (4) presence of a strong EF does not affect extinction of an appetite-motivated task, and (5) presentation of an EF can become a secondary reinforcer. The pattern of results was consistent across all experiments, suggesting that an EF of as much as 65 kV/m is not aversive to nonhuman primates. Separately, the authors demonstrated that the average EF detection threshold for baboons is 12 kV/m. Thus, EF exposure at intensities well above the detection threshold and at species-scaled EF strengths greater than those found environmentally does not appear to be aversive.

  20. Immune function and host defense in rodents exposed to 60-Hz magnetic fields.

    PubMed

    House, R V; Ratajczak, H V; Gauger, J R; Johnson, T R; Thomas, P T; Mccormick, D L

    1996-12-01

    This study was conducted to evaluate the influence of subchronic exposure to pure, linearly polarized 60-Hz magnetic fields (MF) on the host immune response in mice. The experimental design was as follows: three groups were exposed continuously (18.5 hr/day) to MF at field strengths of 0.02, 2, or 10 gauss (G), one group was exposed intermittently (1 hr on/1 hr off) to MF at a field strength of 10 G, and one group served as a sham control. Experimental endpoints included spleen and thymus weights and cellularity, antibody-forming cell (AFC) response, delayed-type hypersensitivity (DTH) response, splenic lymphocyte subset analysis, susceptibility to infection with Listeria monocytogenes, and natural killer (NK) cell activity. No differences in body weight, lymphoid organ weight, or lymphoid organ cellularity were observed in any MF-exposed group in comparison to sham controls. Likewise, no statistically significant differences were found in comparisons of AFC responses. Isolated statistically significant differences from control were observed in MF-exposed mice in the DTH assay, although no clear dose-related pattern of altered activity was seen. Splenic lymphocyte subset parameters examined were within normal limits in all groups, and no differences between control and MF-exposed mice were found. Host resistance to bacterial infection was not altered at any MF exposure examined in this study. Finally, although apparently dose-related, statistically significant alterations were observed in an initial study of NK cell function, repeat studies failed to demonstrate a consistent pattern of alteration.

  1. Reproduction, growth, and development of rats during chronic exposure to multiple field strengths of 60-Hz electric fields

    SciTech Connect

    Rommereim, D.N.; Rommereim, R.L.; Sikov, M.R.; Buschbom, R.L.; Anderson, L.E. )

    1990-04-01

    A study with multiple exposure groups and large group sizes was performed to establish whether exposure to 60-Hz electric fields would result in reproductive and developmental toxicity. A response model was developed from previous results and tested in groups of rats exposed to electric fields at various field strengths. Female rats were mated, and sperm-positive animals randomly distributed among four groups: sham-exposed or exposed to 10, 65, or 130 kV/m, 60-Hz vertical electric fields. Animals were exposed for 19 hr/day throughout the experiment. During gestation, exposure to the higher field strengths resulted in slightly depressed weight gains of dams. Offspring were born in the field and remained with their dams through the suckling period. Numbers of pups per litter and pup mortality did not differ among the exposure groups. Dams exposed at 65 kV/m lost slightly more weight through the lactation period than the control group. Male pups exposed to higher field strengths gained slightly less weight from 4 to 21 days of age than did sham-exposed animals. At weaning, two F1 females per litter (randomly selected) continued on the same exposure regimen were mated at 11 weeks of age to unexposed males, and euthanized at 20 days of gestation. Uterine contents were evaluated, and all live fetuses were weighed and examined for external, visceral, and skeletal malformations. Fertility and gestational weight gain of F1 females were not affected by exposure, nor was prenatal viability or fetal body weight. No significant increase in the incidence of litters with malformations was observed. Although no developmental toxicity was detected, exposures produced physical changes in the dams, evidenced as a rust-colored deposit on the muzzle and ears (chromodacryorrhea) that increased in incidence and severity at 65 and 130 kV/m.

  2. Catecholamine release from cultured bovine adrenal medullary chromaffin cells in the presence of 60-Hz magnetic fields.

    PubMed

    Craviso, Gale L; Chatterjee, Indira; Publicover, Nelson G

    2003-04-01

    Effects of powerline frequency (50/60 Hz) electric and magnetic fields on the central nervous system may involve altered neurotransmitter release. This possibility was addressed by determining whether 60-Hz linearly polarized sinusoidal magnetic fields (MFs) alter the release of catecholamines from cultured bovine adrenal chromaffin cells, a well-characterized model of neural-type cells. Dishes of cells were placed in the center of each of two four-coil Merritt exposure systems that were enclosed within mu-metal chambers in matched incubators for simultaneous sham and MF exposure. Following 15-min MF exposure of the cells to flux densities of 0.01, 0.1, 1.0 or 2 mT, norepinephrine and epinephrine release were quantified by high-performance liquid chromatography (HPLC) coupled with electrochemical detection. No significant differences in the release of either norepinephrine or epinephrine were detected between sham-exposed cells and cells exposed to MFs in either the absence or presence of Bay K-8644 (2 microM) or dimethylphenylpiperazinium (DMPP, 10 microM). Consistent with these null findings is the lack of effect of MF exposure on calcium influx. We conclude that catecholamine release from chromaffin cells is not sensitive to 60-Hz MFs at magnetic flux densities in the 0.01-2 mT range.

  3. Constraints of thermal noise on the effects of weak 60-Hz magnetic fields acting on biological magnetite.

    PubMed Central

    Adair, R K

    1994-01-01

    Previous calculations of limits imposed by thermal noise on the effects of weak 60-Hz magnetic fields on biological magnetite are generalized and extended to consider multiple signals, the possibility of anomalously large magnetosome structures, and the possibility of anomalously small cytoplasm viscosities. The results indicate that the energies transmitted to the magnetite elements by fields less than 5 microT, characteristic of the electric power distribution system, will be much less than thermal noise energies. Hence, the effects of such weak fields will be masked by that noise and cannot be expected to affect biology or, therefore, the health of populations. PMID:8159681

  4. Electric fields induced in chicken eggs by 60-Hz magnetic fields and the dosimetric importance of biological membranes

    SciTech Connect

    Miller, D.L. )

    1991-01-01

    Chicken eggs are convenient models for observing the effects of inhomogeneities and variations, such as those found in biological membranes and in cellular conductivities, on the distribution of internal electric fields as induced by exposure to magnetic fields. The vitelline membrane separates the yolk, which has a conductivity of 0.26 S/m, from the white, which has a conductivity of 0.85 S/m. A miniaturized probe with 2.4-mm resolution was used to measure induced fields in eggs placed in a uniform, 1-mT magnetic field at 60 Hz. The E fields induced in eggs with homogenized contents agreed with expectations based on simple theory. Results were similar to intact eggs unless the probe moved the yolk off-center, which greatly perturbed the induced fields. A more reproducible arrangement, which consisted of saline-agar filled dishes with a hole cut for test samples, was developed to enhance definition of electrical parameters. With this test system, the vitelline membrane was found to be responsible for most of the perturbation of the induced field, because it electrically isolates the yolk from the surrounding white. From a theoretical viewpoint, this dosimetry for the macroscopic egg yolk is analogous to the interaction of fields with microscopic cells. These findings may have important implications for research on biological effects of ELF electromagnetic fields, especially for studies of avian embryonic development.

  5. Chronic exposure to a 60-Hz electric field: effects on synaptic transmission and peripheral nerve function in the rat.

    PubMed

    Jaffe, R A; Laszewski, B L; Carr, D B; Phillips, R D

    1980-01-01

    Several reports have suggested that the nervous system can be affected by exposure to electric fields and that these effects may have detrimental health consequences for the exposed organism. The purpose of this study was to investigate the effects of chronic (30-day) exposure of rats to a 60Hz, 100-kV/m electric field on synaptic transmission and peripheral-nerve function. One hundred forty-four rats, housed in individual polycarbonate cages were exposed to uniform, vertical, 60-Hz electric fields in a system free of corona discharge and ozone formation and in which the animals did not receive spark discharges or other shocks during exposure. Following 30 days of exposure to the electric field, superior cervical sympathetic ganglia, vagus and sciatic nerves were removed from rats anesthetized with urethan, placed in a temperature-controlled chamber, and superfused with a modified mammalian Ringer's solution equilibrated with 95% O2 and 5% CO2. Several measures and tests were used to characterize synaptic transmission and peripheral-nerve function. These included amplitude, area, and configuration of the postsynaptic or whole-nerve compound-action potential; conduction velocity; accommodation; refractory period; strength-duration curves; conditioning-test (C-T) response, frequency response; post-tetanic response; and high-frequency-induced fatigue. The results of a series of neurophysiologic tests and measurements indicate that only synaptic transmission is significantly and consistently affected by chronic (30-day) exposure to a 60-Hz, 100-kV/m electric field. Specifically, and increase in synaptic excitability was detected in replicated measurements of the C-T response ratio. In addition, there are trends in other data that can be interpreted to suggest a generalized increase in neuronal excitability in exposed animals.

  6. Effects of 60 Hz electric fields on operant and social stress behavior of nonhuman primates. Quarterly technical progress report No. 20, September 28-December 20, 1985

    SciTech Connect

    Rogers, W.R.

    1986-01-03

    This research program will evaluate the aversive character of exposure to 60 Hz electric fields by determining the threshold intensity which produces avoidance or escape responses, will estimate the threshold intensity for detection of 60 Hz electric fields, will assess effects of chronic exposure to 60 Hz electric fields on the performance of two operant conditioning tasks, fixed ratio and differential reinforcement of low rate responding, will investigate, using the systematic quantitative observational sampling methods of primatology, the possible stress-inducing effects of chronic exposure to 60 Hz electric fields on the behavior of baboons living in small social groups. In all experiments, the electric fields will be described, characterized, and controlled to account for recognized artifacts associated with high intensity 60 Hz electric fields and the health of all subjects will be described using the methods of primate veterinary medicine.

  7. Effects of 60 Hz electric fields on operant and social stress behaviors of nonhuman primates. Project technical status report, November 23, 1985-January 17, 1986. [Papio cynocephalus

    SciTech Connect

    Not Available

    1986-01-24

    The objective was to investigate, using baboons (superspecies Papio cynocephalus) as surrogates, possible behavioral effects associated with exposure to high intensity 60 Hz electric fields. This program consists of four major projects. The first will evaluate the potential aversive character of exposure to 60 Hz electric fields by determining the threshold intensity which produces avoidance or escape responses. The second project will estimate the threshold intensity for detection of 60 Hz electric fields. The third will assess effects of chronic exposure to 60 Hz electric fields on the performance of two operant conditioning tasks, fixed ratio (FR) and differential reinforcement of low rate responding (DRL). The fourth will investigate the possible stress-inducing effects of chronic exposure to 60 Hz electric fields on the behavior of baboons living in small social groups.

  8. Effects of 60 Hz electric fields on operant and social stress behaviors of nonhuman primates: Projects 3 and 4

    SciTech Connect

    Rogers, W.R.; Coelho, A.M. Jr.; Easley, S.P.; Orr, J.L.; Smith, H.D.; Taylor, L.L.; Tuttle, M.L.

    1987-01-01

    The objective of this program is to investigate, using the baboon as a nonhuman primate surrogate for the human, possible hehavioral effects associated with exposure to high intensity 60 Hz electric fields. Results from this program, along with information from experiments conducted elsewhere, will be used by the Department of Energy (DOE) to estimate and evaluate the likelihood of deleterious consequences resulting from exposure of humans to the electric fields associated with power transmission over high voltage lines. This research program consists of four major research projects, all of which have been successfully completed. The third project assessed, in separate experiments conducted at 30 and 60 kV/m, effects of chronic exposure to electric fields on the performance of two operant conditioning tasks, fixed ratio (FR), and differential reinforcement of low rate (DRL). In the same two experiments, the fourth project investigated, using the systematic quantitative observational sampling methods of primatology, the possible stress-inducing effects of chronic exposure to 60 Hz electric fields on the behavior of baboons living in small social groups. This volume contains only appendices for projects 3 and 4. 81 figs., 67 tabs.

  9. Effects on micronuclei formation of 60-Hz electromagnetic field exposure with ionizing radiation, hydrogen peroxide, or c-Myc overexpression.

    PubMed

    Jin, Yeung Bae; Kang, Ga-Young; Lee, Jae Seon; Choi, Jong-Il; Lee, Ju-Woon; Hong, Seung-Cheol; Myung, Sung Ho; Lee, Yun-Sil

    2012-04-01

    Epidemiological studies have demonstrated a possible correlation between exposure to extremely low-frequency magnetic fields (ELF-MF) and cancer. However, this correlation has yet to be definitively confirmed by epidemiological studies. The principal objective of this study was to assess the effects of 60 Hz magnetic fields in a normal cell line system, and particularly in combination with various external factors, via micronucleus (MN) assays. Mouse embryonic fibroblast NIH3T3 cells and human lung fibroblast WI-38 cells were exposed for 4 h to a 60 Hz, 1 mT uniform magnetic field with or without ionizing radiation (IR, 2 Gy), H(2)O(2) (100 μM) and cellular myelocytomatosis oncogene (c-Myc) activation. The results obtained showed no significant differences between the cells exposed to ELF-MF alone and the unexposed cells. Moreover, no synergistic effects were observed when ELF-MF was combined with IR, H(2)O(2), and c-Myc activation. Our results demonstrate that ELF-MF did not enhance MN frequency by IR, H(2)O(2) and c-Myc activation.

  10. Effects of intermittent 60-Hz high voltage electric fields on metabolism, activity, and temperature in mice

    SciTech Connect

    Rosenbergy, R.S; Duffy, P.H.; Sacher, G.A.

    1981-01-01

    Transient effects of 100-kV/m extremely low frequency electric fields were studied in the white footed deermouse, Peromyscus leucopus. Gross motor activity, carbon dioxide production, oxygen consumption, and core body temperature were monitored before, during, and after intermittent field exposures (four hour-long exposures, at one-hour intervals). Thirty-four mice were exposed in cages with plastic floors floating above ground potential, and 21 mice were exposed in cages with grounded metal floor plates. The first field exposure produced an immediate, transient increase of activity and gas measures during the inactive phase of the circadian cycle. All measures returned to baseline levels before the second exposure and were not significantly changed throughout the remainder of the exposures. The rapid habituation of field-induced arousal suggests that significant metabolic changes will not be measured in experiments in which the interval between exposure and measurement is greater than two hours.

  11. Case-control study of childhood cancer and exposure to 60-Hz magnetic fields

    SciTech Connect

    Savitz, D.A.; Wachtel, H.; Barnes, F.A.; John, E.M.; Tvrdik, J.G.

    1988-07-01

    Concern with health effects of extremely low frequency magnetic fields has been raised by epidemiologic studies of childhood cancer in relation to proximity to electric power distribution lines. This case-control study was designed to assess the relation between residential exposure to magnetic fields and the development of childhood cancer. Eligible cases consisted of all 356 residents of the five-county 1970 Denver, Colorado Standard Metropolitan Statistical Area aged 0-14 years who were diagnosed with any form of cancer between 1976 and 1983. Controls were selected by random digit dialing to approximate the case distribution by age, sex, and telephone exchange area. Exposure was characterized through in-home electric and magnetic field measurements under low and high power use conditions and wire configuration codes, a surrogate measure of long-term magnetic field levels. Measured magnetic fields under low power use conditions had a modest association with cancer incidence; a cutoff score of 2.0 milligauss resulted in an odds ratio of 1.4 (95% confidence interval (CI) = 0.6-2.9) for total cancers and somewhat larger odds ratios (ORs) for leukemias (OR = 1.9), lymphomas (OR = 2.2), and soft tissue sarcomas (OR = 3.3). Neither magnetic fields (OR = 1.0) nor electric fields (OR = 0.9) under high power use conditions were related to total cancers. Wire codes associated with higher magnetic fields were more common among case than control homes. The odds ratio to contrast very high and high to very low, low, and buried wire codes was 1.5 (95% CI = 1.0-2.3) for total cases, with consistency across cancer subgroups except for brain cancer (OR = 2.0) and lymphomas (OR = 0.8). Contrasts of very high to buried wire code homes produced larger, less precise odds ratios of 2.3 for total cases, 2.9 for leukemias, and 3.3 for lymphomas.

  12. Melatonin metabolite levels in workers exposed to 60-Hz magnetic fields: work in substations and with 3-phase conductors.

    PubMed

    Burch, J B; Reif, J S; Noonan, C W; Yost, M G

    2000-02-01

    Melatonin suppression by 50/60-Hz magnetic fields represents a plausible biological mechanism for explaining increased health risks in workers. Personal exposure to magnetic fields and ambient light, and excretion of the melatonin metabolite 6-hydroxymelatonin sulfate (6-OHMS), were measured over 3 consecutive workdays in electric utility workers. There was a magnetic field-dependent reduction in adjusted mean nocturnal and post-work 6-OHMS levels among men working more than 2 hours per day in substation and 3-phase environments and no effect among those working 2 hours or less. No changes were observed among men working in 1-phase environments. The results suggest that circular or elliptical magnetic field polarization, or another factor linked to substations and 3-phase electricity, is associated with magnetic field induced melatonin suppression in humans.

  13. Cancer promotion in a mouse-skin model by a 60-Hz magnetic field: I. Experimental design and exposure system

    SciTech Connect

    Stuchly, M.A.; Lecuyer, D.W.; McLean, J. )

    1991-01-01

    The rationale for selection of an animal model, the experimental design, and the design and evaluation of an exposure system used in studies of 60-Hz magnetic fields are described. The studies were conceived to assay development of cancer and immune responsiveness in mice exposed to magnetic fields. The exposure system utilized a quadrupole-coil configuration to minimize stray magnetic fields. Four square-wound coil provided a uniform field within a volume occupied by 16 animal cages. The magnetic field had a mean flux density of 2 mT that varied less than {plus minus} 10% within the volume occupied by animals' cages. The flux density decreased to less than 0.1 microT at a distance of 2 m from the coils. In each exposure system 32 animals could be housed in plastic cages.

  14. Effects of 60-Hz electric and magnetic fields on operant and social behavior and on neuroendocrine system of nonhuman primates

    SciTech Connect

    Rogers, W.R.; Coelho, A.M.; Easley, S.P.; Orr, J.L.; Reiter, R.J.; Rhodes, J.W.

    1992-09-24

    A series of pioneering electric and magnetic field experiments were completed using nonhuman primates and a unique, well-engineered, and reliable exposure facility. Effects of operant behavior, social behavior, and serum melatonin concentration were examined using 60 Hz field combinations of other 6 W/m and 0.6 G or 30 W/m and 1.0 G. Observations noted in the course of this study include: Combines electric and magnetic field exposure does not have any important effect on short-term memory; the transitory increases in social behavior observed in previous electric fields did not occur; combined electric and magnetic field exposure might lead to reduced behavioral frequency in baboon social groups; three experiments clearly establish that one set of exposure conditions does not produce molatonin suppression in nonhuman primates; and a small pilot experiment suggests that a different exposure protocol might result in melatonin suppression.

  15. Growth rate and mitotic index analysis of Vicia faba L. roots exposed to 60-Hz electric fields

    SciTech Connect

    Inoue, M.; Miller, M.W.; Cox, C.; Carstesen, E.L.

    1985-01-01

    Growth, mitotic index, and growth rate recovery were determined for Vicia faba L. roots exposed to 60-Hz electric fields of 200, 290, and 360 V/m in an aqueous inorganic nutrient medium (conductivity 0.07-0.09 S/m). Root growth rate decreased in proportion to the increasing strength; the electric field threshold for a growth rate effect was about 230 V/m. The induced transmembrane potential at the threshold exposure was about 4-7 mV. The mitotic index was not affected by an electric field exposure sufficient to reduce root growth rate to about 35% of control. Root growth rate recovery from 31-96% of control occurred in 4 days after cessation of the 360 V/m exposure. The results support the postulate that the site of action of the applied electric fields is the cell membrane. 10 references, 4 figures, 4 tables.

  16. Immunological and biochemical effects of 60-Hz electric and magnetic fields in humans

    SciTech Connect

    Graham, C.; Cohen, H.D.

    1988-01-08

    Public concern has been expressed about possible health risks arising from exposure to powerline electric and magnetic fields. This project is addressing this concern through a research program designed to evaluate the effects of exposure to known field conditions on multiple measures of human function. The present phase of project activities began in October 1985, and will end in September 1988. Two of the three tasks to be accomplished in this phase have now been completed. During the present reporting period, project staff designed and began preparations for Task 3. These plans were reviewed at the two project review meetings held in the present reporting period, and data collection on the Task 3 study is scheduled to begin in the next reporting period. Project goals during this reporting period were to: complete analysis of intermittent exposure study; attend the annual DOE/EPRI contractors review meeting; participate in project review meetings; and design and prepare for Task 3. Data collection for this study ended in the previous reporting period. The following activities were performed to complete the required statistical analyses: electrophysiological data were screened for artifacts, scored, and entered into the compute data base; urine samples were assayed for cortisol, dopamine, epinephrine, and norepinephrine; performance data were verified and entered into the data base; subjective data were verified and entered into the data base; and multivariate and univariate statistical tests were performed to evaluate the effects of the exposure conditions on the above measures.

  17. Effects of exposure to a 60-kV/m, 60-Hz electric field on the social behavior of baboons

    SciTech Connect

    Easley, S.P.; Coelho, A.M. Jr.; Rogers, W.R. )

    1991-01-01

    The authors found in a previously reported study that exposure to a 30-kV/m, 60-Hz electric field had significant effects on the social behavior of baboons. However, it was not established whether or not the effects were related specifically to the 30-kV/m intensity of the field. A new experiment was conducted to determine whether or not exposure to a 60-Hz electric field at 60 kV/m would produce like changes in the baboons' social behavior. They exposed one group of eight male baboons to an electric field 12 hours a day, 7 days a week, for 6 weeks. A second group of eight animals was maintained under sham-exposure (control) conditions. Rates of performing on each of six categories of social behavior and on four categories of nonsocial behavior were used as criteria for comparing exposed with unexposed subjects and for within-group comparisons during three six-week experimental periods: Pre-Exposure, Exposure, and Post-Exposure. The results indicate that (1) during the exposure period, exposed animals exhibited statistically significant differences from controls in means of performance rates based on several behavioral categories; (2) across all three periods, within-group comparisons revealed that behaviors of exposed baboons were significantly affected by exposure to the electric field; (3) changes in performance levels probably reflect a stress response to the electric field; and (4) the means of response rates of animals exposed at 60 kV/m were higher, but not double, those of animals exposed at 30 kV/m. As in the 30-kV/m experiment, animals exposed at 60 kV/m exhibited significant differences in performances of Passive Affinity, Tension, and Stereotypy. Mean rates of performing these categories were 122% (Passive Affinity), 48% (Tension), and 40% (Stereotypy) higher in the exposed group than in the control group during exposure to the 60-kV/m field.

  18. BIGEL analysis of gene expression in HL60 cells exposed to X rays or 60 Hz magnetic fields

    NASA Technical Reports Server (NTRS)

    Balcer-Kubiczek, E. K.; Zhang, X. F.; Han, L. H.; Harrison, G. H.; Davis, C. C.; Zhou, X. J.; Ioffe, V.; McCready, W. A.; Abraham, J. M.; Meltzer, S. J.

    1998-01-01

    We screened a panel of 1,920 randomly selected cDNAs to discover genes that are differentially expressed in HL60 cells exposed to 60 Hz magnetic fields (2 mT) or X rays (5 Gy) compared to unexposed cells. Identification of these clones was accomplished using our two-gel cDNA library screening method (BIGEL). Eighteen cDNAs differentially expressed in X-irradiated compared to control HL60 cells were recovered from a panel of 1,920 clones. Differential expression in experimental compared to control cells was confirmed independently by Northern blotting of paired total RNA samples hybridized to each of the 18 clone-specific cDNA probes. DNA sequencing revealed that 15 of the 18 cDNA clones produced matches with the database for genes related to cell growth, protein synthesis, energy metabolism, oxidative stress or apoptosis (including MYC, neuroleukin, copper zinc-dependent superoxide dismutase, TC4 RAS-like protein, peptide elongation factor 1alpha, BNIP3, GATA3, NF45, cytochrome c oxidase II and triosephosphate isomerase mRNAs). In contrast, BIGEL analysis of the same 1,920 cDNAs revealed no differences greater than 1.5-fold in expression levels in magnetic-field compared to sham-exposed cells. Magnetic-field-exposed and control samples were analyzed further for the presence of mRNA encoding X-ray-responsive genes by hybridization of the 18 specific cDNA probes to RNA from exposed and control HL60 cells. Our results suggest that differential gene expression is induced in approximately 1% of a random pool of cDNAs by ionizing radiation but not by 60 Hz magnetic fields under the present experimental conditions.

  19. BIGEL analysis of gene expression in HL60 cells exposed to X rays or 60 Hz magnetic fields

    NASA Technical Reports Server (NTRS)

    Balcer-Kubiczek, E. K.; Zhang, X. F.; Han, L. H.; Harrison, G. H.; Davis, C. C.; Zhou, X. J.; Ioffe, V.; McCready, W. A.; Abraham, J. M.; Meltzer, S. J.

    1998-01-01

    We screened a panel of 1,920 randomly selected cDNAs to discover genes that are differentially expressed in HL60 cells exposed to 60 Hz magnetic fields (2 mT) or X rays (5 Gy) compared to unexposed cells. Identification of these clones was accomplished using our two-gel cDNA library screening method (BIGEL). Eighteen cDNAs differentially expressed in X-irradiated compared to control HL60 cells were recovered from a panel of 1,920 clones. Differential expression in experimental compared to control cells was confirmed independently by Northern blotting of paired total RNA samples hybridized to each of the 18 clone-specific cDNA probes. DNA sequencing revealed that 15 of the 18 cDNA clones produced matches with the database for genes related to cell growth, protein synthesis, energy metabolism, oxidative stress or apoptosis (including MYC, neuroleukin, copper zinc-dependent superoxide dismutase, TC4 RAS-like protein, peptide elongation factor 1alpha, BNIP3, GATA3, NF45, cytochrome c oxidase II and triosephosphate isomerase mRNAs). In contrast, BIGEL analysis of the same 1,920 cDNAs revealed no differences greater than 1.5-fold in expression levels in magnetic-field compared to sham-exposed cells. Magnetic-field-exposed and control samples were analyzed further for the presence of mRNA encoding X-ray-responsive genes by hybridization of the 18 specific cDNA probes to RNA from exposed and control HL60 cells. Our results suggest that differential gene expression is induced in approximately 1% of a random pool of cDNAs by ionizing radiation but not by 60 Hz magnetic fields under the present experimental conditions.

  20. BIGEL analysis of gene expression in HL60 cells exposed to X rays or 60 Hz magnetic fields.

    PubMed

    Balcer-Kubiczek, E K; Zhang, X F; Han, L H; Harrison, G H; Davis, C C; Zhou, X J; Ioffe, V; McCready, W A; Abraham, J M; Meltzer, S J

    1998-12-01

    We screened a panel of 1,920 randomly selected cDNAs to discover genes that are differentially expressed in HL60 cells exposed to 60 Hz magnetic fields (2 mT) or X rays (5 Gy) compared to unexposed cells. Identification of these clones was accomplished using our two-gel cDNA library screening method (BIGEL). Eighteen cDNAs differentially expressed in X-irradiated compared to control HL60 cells were recovered from a panel of 1,920 clones. Differential expression in experimental compared to control cells was confirmed independently by Northern blotting of paired total RNA samples hybridized to each of the 18 clone-specific cDNA probes. DNA sequencing revealed that 15 of the 18 cDNA clones produced matches with the database for genes related to cell growth, protein synthesis, energy metabolism, oxidative stress or apoptosis (including MYC, neuroleukin, copper zinc-dependent superoxide dismutase, TC4 RAS-like protein, peptide elongation factor 1alpha, BNIP3, GATA3, NF45, cytochrome c oxidase II and triosephosphate isomerase mRNAs). In contrast, BIGEL analysis of the same 1,920 cDNAs revealed no differences greater than 1.5-fold in expression levels in magnetic-field compared to sham-exposed cells. Magnetic-field-exposed and control samples were analyzed further for the presence of mRNA encoding X-ray-responsive genes by hybridization of the 18 specific cDNA probes to RNA from exposed and control HL60 cells. Our results suggest that differential gene expression is induced in approximately 1% of a random pool of cDNAs by ionizing radiation but not by 60 Hz magnetic fields under the present experimental conditions.

  1. Effect of 60 Hz electromagnetic fields on the activity of hsp70 promoter: an in vivo study

    PubMed Central

    Rodríguez-De la Fuente, Abraham O.; Alcocer-González, Juan M.; Heredia-Rojas, J. Antonio; Rodríguez-Padilla, Cristina; Rodríguez-Flores, Laura E.; Santoyo-Stephano, Martha A.; Castañeda-Garza, Esperanza; Taméz-Guerra, Reyes S.

    2012-01-01

    Exposure to EMFs (electromagnetic fields) results in a number of important biological changes, including modification of genetic expression. We have investigated the effect of 60 Hz sinusoidal EMFs at a magnetic flux density of 80 μT on the expression of the luciferase gene contained in a plasmid labelled as pEMF (EMF plasmid). This gene construct contains the specific sequences for the induction of hsp70 (heat-shock protein 70) expression by EMFs, as well as the reporter for the luciferase gene. The pEMF vector was electrotransferred into quadriceps muscles of BALB/c mice that were later exposed to EMFs. Increased luciferase expression was observed in mice exposed to EMFs 2 h daily for 7 days compared with controls (P<0.05). These data along with other reports in the literature suggest that EMFs can have far-reaching effects on the genome. PMID:23124775

  2. Study of the behavioral and biological effects of high strength 60 HZ electric fields. Quarterly technical progress report No. 15, 12 May 1984-3 August 1984

    SciTech Connect

    Not Available

    1984-08-15

    Progress is reported in the construction of a test facility for studying the effects of high intensity, 60 Hz electric fields on baboons. Effects to be studied include operant out social behaviors. (ACR)

  3. Cancer promotion in a mouse-skin model by a 60-Hz magnetic field: II. Tumor development and immune response.

    PubMed

    McLean, J R; Stuchly, M A; Mitchel, R E; Wilkinson, D; Yang, H; Goddard, M; Lecuyer, D W; Schunk, M; Callary, E; Morrison, D

    1991-01-01

    This paper describes preliminary findings on the influence of 60-Hz (2-mT) magnetic fields on tumor promotion and co-promotion in the skins of mice. The effect of magnetic fields on natural killer (NK) cell activity in spleen and blood was also examined. Groups of 32 juvenile female mice were exposed to the magnetic field as described in part I. The dorsal skin of all animals was treated with a subthreshold dose of the carcinogen 7,12-dimethyl-benz(a)anthracene (DMBA). One week after the treatment, two groups were sham exposed (group A) or field exposed at 2 mT (group B) 6 h/day for 21 weeks, to test whether the field would act as a tumor promoter. No tumors developed in these two groups of mice. To test whether the magnetic field would modify tumor development by directly affecting tumor growth or by suppressing immune surveillance, two additional groups of mice were treated weekly with the tumor promoter 12-0-tetradecanoylphorbol-13-acetate (TPA) and then either sham exposed (group C) or field exposed (group D). The time to appearance of tumors was shorter (but not statistically so) in the group exposed to magnetic fields and TPA. Some differences in NK cell activity and spleen size were observed between the sham- and field-exposed groups.

  4. No effect of 60 Hz electromagnetic fields on MYC or {beta}-actin expression in human leukemic cells

    SciTech Connect

    Lacy-Hulbert, A.; Wilkins, R.C.; Hesketh, T.R.

    1995-10-01

    Epidemiological studies have shown weak correlations between exposure to extremely low-frequency electromagnetic fields (ELF EMFs) and the incidence of several cancers, particularly childhood leukemias, although negative studies have also been reported. These observations have prompted a broad range of in vitro cellular studies in which effects of ELF EMFs have been observed. However, no reported response has been replicated widely in independent laboratories. One potentially important response is the rapid activation of proto-oncogenes and other genes in human leukemic (HL60) cells and a wide variety of other eukaryotic cells, because of the role of these genes in cell proliferation. We describe quantitative Northern analysis of MYC and {beta}actin mRNAs from HL60 cells exposed to fields under conditions very similar to those reported previously to activate these genes, namely 60 Hz sinusoidal magnetic fields of 0.57, 5.7 or 57 {mu}T for 20 min. In addition we have used a new design of field-exposure system and introduced a number of other modifications to the protocol to optimize any response. We have also developed a novel method providing enhanced accuracy for the quantitative measurement of mRNA. No significant effect of ELF EMFs on gene expression was observed using any of these systems and analytical methods. 70 refs., 2 figs., 1 tab.

  5. Biological studies of swine exposed to 60-Hz electric fields. Volume 1. Overview and summary. Final report

    SciTech Connect

    Not Available

    1985-12-01

    Over a three-year period, three generations of female miniature swine and their offspring were exposed to a 30-kV/m, 60-Hz electric field. Such a field approximates the 12-kV/m field that a human would experience under a 765-kV line. After swine exposures varying from 6 to 36 months, project personnel analyzed a wide range of biological parameters including growth, blood cell and serum biochemistry, blood immunoglobulin levels, behavior, peripheral nerve function, cell-mediated immunity, cytogenetics, and reproduction and development. There were no significant differences in health effects between the exposed and sham-exposed swine, except in the area of fetal development. The first breeding produced no significant difference between exposed and control offspring. When those offspring were bred after 18 months of exposure, the fetuses of exposed sows had an increased incidence of morphological malformations and lower body weight than fetuses from control sows. The live-born had lower body weights and increased birth defects. Several factors suggest that electric fields per se may not have caused these reproductive changes. For example, similar types of malformations occurred in control pigs. Also, in second-generation sows, the incidence of fetal malformations was similar for both exposed and control groups. It is possible that other factors such as housing, inbreeding, disease, or treatment of disease may have produced the observed effects. 64 refs., 13 figs., 25 tabs.

  6. Effect of 60 Hz electromagnetic fields on the activity of hsp70 promoter: an in vitro study.

    PubMed

    Rodríguez de la Fuente, Abraham O; Alcocer-González, Juan M; Antonio Heredia-Rojas, J; Balderas-Candanosa, Isaías; Rodríguez-Flores, Laura E; Rodríguez-Padilla, Cristina; Taméz-Guerra, Reyes S

    2009-03-01

    We have evaluated the effect of 60 Hz sinusoidal magnetic fields (MF) at 8 and 8 microT on expression of the luciferase gene contained in a gene construct labelled as Electromagnetic Field-plasmid (pEMF). The vector included the hsp70 promotor containing the 3 nCTCTn sequences previously described for the induction of hsp70 expression by magnetic fields, as well as the reporter of the luciferase gene. We also replicated the study of Lin et al. [Lin H, Blank M, Rossol-Haseroth K, Goodman R. Regulating genes with electromagnetic response elements. J Cell Biochem 2001;81(1):143-48]. The pEMF plasmid was transfected into HeLa and BMK16 cell lines that were later exposed to either MF or thermal shock (TS). An increased luciferase expression was found in both the cells exposed to MF and TS compared with their control groups (P < 0.05). Furthermore, the combined effect of MF and TS was also analyzed. A synergistic effect between two factors was observed for this co-exposure condition in terms of luciferase gene expression.

  7. Effects of exposure to 30 kV/m, 60-Hz electric fields on the social behavior of baboons

    SciTech Connect

    Coelho, A.M. Jr.; Easley, S.P.; Rogers, W.R. )

    1991-01-01

    The authors tested the hypothesis that exposure to a 30-kV/m, 60-Hz electric field produces significant change (stress) in the social behavior of adult male baboons (Papio cynocephalus anubis). One group of eight baboons was exposed to an electric field (12 hours per day, 7 days per week for 6 weeks) while a second group of eight baboons was maintained in a sham-exposure (control) condition. Exposed subjects and control subjects were compared over three, six-week experimental periods (pre-exposure, exposure, and post-exposure). Performance rates of six categories of social behaviors (passive affinity, active affinity, approach, tension, threat, and attack) and four categories of nonsocial behaviors (forage, manipulate, posture, and stereotypy) were used to compare the two groups. The results of our study indicate that (1) there were no significant differences between the two groups during the pre-exposure or post-exposure periods; (2) during the exposure period, experimental and control groups exhibited statistically significant differences in the mean performance rates of three behavior categories; (3) within-group comparisons across periods indicate that the experimentally exposed group exhibited statistically significant changes in passive affinity, tension, and stereotypy; and (4) changes in behavior performance among the exposed subjects reflect a stress response to the electric field.

  8. A 60 Hz electric and magnetic field exposure facility for nonhuman primates: Design and operational data during experiments

    SciTech Connect

    Rogers, W.R.; Lucas, J.H.; Cory, W.E.; Orr, J.L.; Smith, H.D.

    1995-12-31

    A unique exposure facility was designed and constructed to generate large-scale vertical electric fields (EF) of up to 65 kV/m and horizontal magnetic fields (MF) of up to 100 {micro}T (1G), so that the behavioral and neuroendocrine effects of 60 Hz EF or combined electric and magnetic field (E/MF) exposure could be examined using nonhuman primates as subjects. Facility design and operational problems and their solutions are presented, and representative operational data from four sets of experiments are provided. A specially designed, optically isolated, 4 cm spherical-dipole EF probe and a commercially available MF probe were used to map the EF and MF within the fiberglass animal cages. In addition, amplifiers, signal conditioners, and A/D converters provided EF, MF, and transformer signals to a microcomputer at 15 min intervals. The apparatus produced homogeneous, stable E/MF at the desired intensities, and the fiberglass cages did not produce appreciable distortion or attenuation. Levels of recognized EF artifacts such as corona and ozone were negligible. The facility worked as intended, providing a well-characterized and artifact-controlled environment for experiments with baboons (Papio cynocephalus).

  9. Inhibitory effects of 60-Hz magnetic fields on opiate-induced "analgesia" in the land snail, Cepaea nemoralis, under natural conditions.

    PubMed

    Tysdale, D M; Lipa, S M; Ossenkopp, K P; Kavaliers, M

    1991-01-01

    There is accumulating laboratory evidence that magnetic fields can affect a variety of opioid-mediated behavioral and physiological functions in both vertebrates and invertebrates. The present study examined the effects of various durations (0.50, 1.0 and 2.0 h) of exposure to a low intensity (1.0 gauss rms) 60-Hz magnetic field on opioid-mediated aversive thermal ("nociceptive") responses and morphine-induced "analgesia" in the land snail, Cepaea nemoralis, under natural environmental conditions. Exposure to the powerline-related 60-Hz magnetic fields significantly attenuated morphine-induced analgesia and the basal nociceptive responses of Cepaea, with the degree of attenuation being related to the duration of exposure to the magnetic fields. These results with Cepaea show that 60-Hz magnetic fields can affect opioid-mediated behavioral responses outside the laboratory under natural environmental conditions.

  10. Study of the behavioral and biological effects of high-strength 60-Hz electric fields. Quarterly progress report, 11 October 1981-10 January 1982. [Research plan

    SciTech Connect

    Rogers, W.R.

    1982-01-01

    The primary objective of this research is to study the effects of high intensity, 60 Hz electric fields on baboon behavior to obtain information which will assist in the determination of the degree of risk of deleterious consequences for humans exposed to such fields. The generalization of results obtained with the baboon to predictions concerning humans will be aided by the development of computer models relating the surface electric field intensities and internal current densities produced in baboons and humans by exposure to high intensity, 60 Hz electric fields. Research plans are described.

  11. Study of the behavioral and biological effects of high-strength 60-Hz electric fields. Quarterly technical progress report number 10, 18 December 1982-18 March 1983

    SciTech Connect

    Not Available

    1983-04-20

    The objective of this contract is to use the baboon as a surrogate for the human in studies of the possible deleterious effects of exposure to high strength, 60 Hz electric fields. The specific aims of this contract are to (1) design and construct an exposure facility in which baboons can be exposed to an electric field up to 60 kV/m in intensity for experiments and (2) to develop computer models relating the fields and currents produced in both baboons and humans by exposure to high strength, 60 Hz electric fields.

  12. Biological studies of swine exposed to 60-Hz electric fields. Volume 4: growth, reproduction, and development. Final report

    SciTech Connect

    Not Available

    1985-12-01

    Swine were exposed to uniform, vertical, 60-Hz, 30-kV/m electric fields for 20 hours/day, 7 days/week. The parental generation (F/sub 0/ gilts) was bred after 4 months on study; some were killed for teratologic study at 100 days of gestation (dg), and the others produced a first-generation (F/sub 1/) of offspring. The pooled incidence of terata in these litters was similar in the exposed and sham-exposed groups. The F/sub 0/ females, which produced the F/sub 1/ generation, were rebred after 18 months of exposure and were killed at 100 dg: malformation incidence in exposed litters (75%) was significantly greater than in sham-exposed litters (29%). Types of malformations were not dissimilar between the two groups. The F/sub 1/ gilts were bred at 18 months of age; there were indications of impaired copulatory behavior and decreased fertility in the exposed animals. Defective offspring were found in significantly more of the exposed litters (71%) than in sham-exposed litters (33%). The F/sub 1/ sows were bred again 10 months later, and teratologic evaluations were performed on their second litters at 100 dg. The percentage of litters with malformed fetuses was essentially identical in the exposed and sham-exposed groups (70 and 73%, respectively). The change in malformation incidences between generations and between the first and second breedings makes it difficult to unequivocally conclude that chronic exposure to a strong electric field caused developmental effects in swine, although it appears there may be an association. It is also possible that other factors, such as housing, inbreeding, disease or its treatment may have contributed to the results. 22 refs., 9 figs., 28 tabs.

  13. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates

    SciTech Connect

    Rhodes, J.W.

    1992-09-24

    The objective of this program is to investigate behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields (E/MF), using the baboon (Papio cynocephalus) as a nonhuman primate surrogate for the human. Results from this program, along with information from experiments conducted elsewhere, could be used to estimate and evaluate the likelihood of deleterious consequences of human exposure to the electric and magnetic fields associated with electric power transmission. This report covers a series of three experiments (Experiments III, IV, and IVA) on the effect of combined 60-Hz E/MF on operant behavior. These experiments were a continuation of previous investigations of 60-Hz electric field exposure on baboons.

  14. Effects of 60 Hz electromagnetic fields on early growth in three plant species and a replication of previous results.

    PubMed

    Davies, M S

    1996-01-01

    In an attempt to replicate the findings of Smith et al., seeds of Raphanus sativus L. (radish), Sinapsis alba L. (mustard), and Hordeum vulgare L. (barley) were grown for between 9 and 21 days in continuous electromagnetic fields (EMFs) at "ion-cyclotron resonance" conditions for stimulation of Ca(2+) (B(H) = 78.3 mu T, B(HAC) = 40 mu T peak-peak at 60 Hz, B(V) = 0). On harvesting, radish showed results similar to those of Smith et al. Dry stem weight and plant height were both significantly greater (Mann-Whitney tests, Ps < 0.05) in EMF-exposed plants than in control plants in each EMF experiment. Wet root weight was significantly greater in EMF-exposed plants in two out of three experiments, as were dry leaf weight, dry whole weight, and stem diameter. Dry root weight, wet leaf weight, and wet whole weight were significantly greater in EMF-exposed plants in one of three experiments. All significant differences indicated an increase in weight or size in the EMF-exposed plants. In each of the sham experiments, no differences between exposed and control plants were evident. Mustard plants failed to respond to the EMFs in any of the plant parameters measured. In one experiment, barley similarly failed to respond; but in another showed significantly greater wet root weight and significantly smaller stem diameter and dry seed weight at the end of the experiment in exposed plants compared to control plants. Although these results give no clue about the underlying bioelectromagnetic mechanism, they demonstrate that, at least for one EMF-sensitive biosystem, results can be independently replicated in another laboratory. Such replication is crucial in establishing the validity of bioelectromagnetic science.

  15. Effects of 60 Hz electromagnetic fields on early growth in three plant species and a replication of previous results

    SciTech Connect

    Davis, M.S.

    1996-05-01

    In an attempt to replicate the findings of Smith et al., seeds of Raphanus sativus L. (radish), Sinapsis alba L. (mustard), and Hordeum vulgare L. (barley) were grown for between 9 and 21 days in continuous electromagnetic fields (EMFs) at ion-cyclotron resonance conditions for stimulation of Ca{sup 2+} (B{sub H} = 78.3 {micro}T, B{sub HAC} = 40 {micro}T peak-peak at 60 Hz, B{sub v} = 0). On harvesting, radish showed results similar to those of Smith et al. Dry stem weight and plant height were both significantly greater (Mann-Whitney tests, Ps < 0.05) in EMF-exposed plants than in control plants in each EMF experiment. Wet root weight was significantly greater in EMF-exposed plants in two out of three experiments, as were dry leaf weight, dry whole weight, and stem diameter. Dry root weight, wet leaf weight, and wet whole weight were significantly greater in EMF-exposed plants in one of three experiments. All significant differences indicated an increase in weight or size in the EMF-exposed plants. In each of the sham experiments, no differences between exposed and control plants were evident. Mustard plants failed to respond to the EMFs in any of the plant parameters measured. In one experiment, barley similarly failed to respond; but in another showed significantly greater wet root weight and significantly smaller stem diameter and dry seed weight at the end of the experiment in exposed plants compared to control plants. Although these results give no clue about the underlying bioelectromagnetic mechanism, they demonstrate that, at least for one EMF-sensitive biosystem, results can be independently replicated in another laboratory. Such replication is crucial in establishing the validity of bioelectromagnetic science.

  16. Effects of 60 Hz Magnetic Field Exposure on the Pineal and Hypothalamic-Pituitary-Gonadal Axis in the Siberian Hamster (Phodopus Sungorus)

    SciTech Connect

    Wilson, Bary W. ); Matt, Kathleen S.; Morris, James E. ); Sasser, Lyle B. ); Miller, Douglas L. ); Anderson, Larry E. )

    1999-11-15

    Experiments using the dwarf Siberian hamster Phodopus sungorus were carried out to determine possible neuroendocrine consequences of one-time and repeated exposures to 60 Hz magnetic fields (MF). Animals were maintained in either a short-light (SL, 8 h light:16 h dar) or long-light (LL, 16 h light:8h dark) photoperiod.

  17. [Effects of 50 to 60 Hz and of 20 to 50 kHz magnetic fields on the operation of implanted cardiac pacemakers].

    PubMed

    Frank, R; Souques, M; Himbert, C; Hidden-Lucet, F; Petitot, J C; Fontaine, G; Lambrozo, J; Magne, I; Bailly, J M

    2003-04-01

    The effect of 50 Hz and 60 Hz (frequencies of current distribution) and 20 kHz to 50 kHz (frequencies of induction cooktop) magnetic interference on implanted pacemakers have been assessed with the present generation of device technology. Sixty patients implanted in 1998 and 1999 with dual chamber pacemakers from 9 different manufacturers were monitored with telemetry while passing through, and standing between a system of two coils. They generated a 50 Hz or a 60 Hz magnetic field at 50 microT. Then, patients used a cooktop at different power. The recordings were made with the standard setting of "medically correct" sensing parameters chosen for the patients. Then pacemakers were reprogrammed to the unipolar mode, with the highest atrial (A) and ventricular (V) sensitivity that did not induce muscular inhibition while moving. Between each exposure (50 Hz, 60 Hz or 20 kHz to 50 kHz), the pacemaker programmation was controlled. At the end of the tests, pacemakers will be reprogrammed with the standard setting. The medical observer being blind to the existence or not of the magnetic field. No pacemaker was influenced by the vicinity of the magnetic field at medically correct settings. At unipolar high sensitivity, no inhibition nor reprogramming was observed. Transient reversion to interference mode was observed in 6 cases, 3 transient acceleration due to atrial detection of the interference, and one T wave detection by the ventricular lead. All were observed with the 60 Hz, and only 3 with the 50 Hz magnetic field. One device (Biotronik) shifted out of its special program (hysteresis research) during the tests with the induction cooktop, but it maintained its standard program, and the event could not be repeated despite further testing. Actual pacemakers do not present any electromagnetic interference with 50 Hz and 60 Hz or induction cooktop frequency working. They are insensitive with medically correct settings. Unusual high sensitivity leads only to noise

  18. Effects of a 30 kV/m, 60 Hz electric field on the social behavior of baboons: A crossover experiment

    SciTech Connect

    Easley, S.P.; Coelho, A.M. Jr.; Rogers, W.R. )

    1992-01-01

    Using a crossover experimental design, we evaluated our earlier findings that exposure to a 30 kV/m, 60 Hz electric field for 12 hours per day, 7 days per week for 6 weeks produced significant changes in the performance rates of social behaviors among young adult male baboons. In the crossover experiment, the former control group was exposed to a 30 kV/m, 60 Hz electric field for 3 weeks. Only an extremely small, incidental magnetic field was generated by the exposure apparatus. We found that electric-field exposure again produced increases in the performance rates that index Passive Affinity, Tension, and Stereotypy. These findings, combined with results from our other electric-field experiments, indicate that exposure to strong electric fields, in the absence of associated magnetic fields, consistently produces effects that are expressed as increases in rates of performance of social behaviors in young adult male baboons.

  19. Intracellular Ca2+ Mobilization and Beta-hexosaminidase Release Are Not Influenced by 60 Hz-electromagnetic Fields (EMF) in RBL 2H3 Cells

    PubMed Central

    Hwang, Yeon Hee; Song, Ho Sun; Kim, Hee Rae; Ko, Myoung Soo; Jeong, Jae Min; Kim, Yong Ho; Ryu, Jeong Soo; Sohn, Uy Dong; Gimm, Yoon-Myoung; Myung, Sung Ho

    2011-01-01

    The effects of extremely low frequency electromagnetic fields (EMF) on intracellular Ca2+ mobilization and cellular function in RBL 2H3 cells were investigated. Exposure to EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h did not produce any cytotoxic effects in RBL 2H3 cells. Melittin, ionomycin and thapsigargin each dose-dependently increased the intracellular Ca2+ concentration. The increase of intracellular Ca2+ induced by these three agents was not affected by exposure to EMF (60 Hz, 1 mT) for 4 or 16 h in RBL 2H3 cells. To investigate the effect of EMF on exocytosis, we measured beta-hexosaminidase release in RBL 2H3 cells. Basal release of beta-hexosaminidase was 12.3±2.3% in RBL 2H3 cells. Exposure to EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h did not affect the basal or 1 µM melittin-induced beta-hexosaminidase release in RBL 2H3 cells. This study suggests that exposure to EMF (60 Hz, 0.1 or 1 mT), which is the limit of occupational exposure, has no influence on intracellular Ca2+ mobilization and cellular function in RBL 2H3 cells. PMID:22128265

  20. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates

    SciTech Connect

    Orr, J.L.

    1990-04-01

    The objective of this program is to investigate, using the baboon as a nonhuman primate surrogate for the human, behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields. Results from this program, along with information from experiments conducted elsewhere, could be used to estimate and evaluate the likelihood of deleterious consequences resulting from exposure of humans to the electric and magnetic fields associated with electric power transmission. Activities this quarter extended those of the first project year: the modification of the facility to include 60-Hz magnetic fields, and development of the capability for studies of neuroendocrine parameters by obtaining blood samples from baboons during electric and magnetic field exposure. 18 figs., 7 tabs.

  1. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine systems of nonhuman primates

    SciTech Connect

    Orr, J.L.

    1990-01-01

    The objective of this program is to investigate, using the baboon as a nonhuman primate surrogate for the human, behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields. Results from this program, along with information from experiments conducted elsewhere, could be used to estimate and evaluate the likelihood of deleterious consequences resulting from exposure of humans to the electric and magnetic fields associated with electric power transmission. Activities this quarter extended those of the first project year which focused on two technical areas: the modification of the facility to include 60-Hz magnetic fields, and development of the capability for studies of neuroendocrine parameters by obtaining blood samples from baboons during electric and magnetic field exposure. 25 figs., 11 tabs.

  2. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates

    SciTech Connect

    Smith, H.D.

    1993-01-22

    The objective of this program is to investigate behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields (E/MF), using the baboon (Papio cynocephalus) as a nonhuman primate surrogate for the human. Results from this program, along with information from experiments conducted elsewhere, could be used to estimate and evaluate the likelihood of deleterious consequences of human exposure to the electric and magnetic fields associated with electric power transmission.

  3. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates. Annual report, FY1992

    SciTech Connect

    Smith, H.D

    1993-01-22

    The objective of this program is to investigate behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields (E/MF), using the baboon (Papio cynocephalus) as a nonhuman primate surrogate for the human. Results from this program, along with information from experiments conducted elsewhere, could be used to estimate and evaluate the likelihood of deleterious consequences of human exposure to the electric and magnetic fields associated with electric power transmission.

  4. Effects of 3 Hz and 60 Hz Extremely Low Frequency Electromagnetic Fields on Anxiety-Like Behaviors, Memory Retention of Passive Avoidance and Electrophysiological Properties of Male Rats

    PubMed Central

    Rostami, Amin; Shahani, Minoo; Zarrindast, Mohammad Reza; Semnanian, Saeed; Rahmati Roudsari, Mohammad; Rezaei Tavirani, Mostafa; Hasanzadeh, Hadi

    2016-01-01

    Introduction: The effects of electromagnetic fields on biological organisms have been a controversial and also interesting debate over the past few decades, despite the wide range of investigations, many aspects of extremely low frequency electromagnetic fields (ELF/EMFs) effects including mechanism of their interaction with live organisms and also their possible biological applications still remain ambiguous. In the present study, we investigated whether the exposures of ELF/EMF with frequencies of 3 Hz and 60 Hz can affect the memory, anxiety like behaviors, electrophysiological properties and brain’s proteome in rats. Methods: Male rats were exposed to 3 Hz and 60 Hz ELF/EMFs in a protocol consisting of 2 cycles of 2 h/day exposure for 4 days separated with a 2-day interval. Short term memory and anxiety like behaviors were assessed immediately, 1 and 2 weeks after the exposures. Effects of short term exposure were also assessed using electrophysiological approach immediately after 2 hours exposure. Results: Behavioral test revealed that immediately after the end of exposures, locomotor activity of both 3 Hz and 60 Hz exposed groups significantly decreased compared to sham group. This exposure protocol had no effect on anxiety like behavior during the 2 weeks after the treatment and also on short term memory. A significant reduction in firing rate of locus coeruleus (LC) was found after 2 hours of both 3 Hz and 60 Hz exposures. Proteome analysis also revealed global changes in whole brain proteome after treatment. Conclusion: Here, some evidence regarding the fact that such exposures can alter locomotor activity and neurons firing rate in male rats were presented. PMID:27330708

  5. Modelling fields induced in humans by 50/60 Hz magnetic fields: reliability of the results and effects of model variations

    NASA Astrophysics Data System (ADS)

    Caputa, K.; Dimbylow, P. J.; Dawson, T. W.; Stuchly, M. A.

    2002-04-01

    This paper presents a comparison of anatomically realistic human models and numerical codes in the dosimetry of power frequency magnetic fields. The groups at the University of Victoria and the National Radiological Protection Board have calculated the induced electric fields in both their 'UVic' and 'NORMAN' models using independently developed codes. A detailed evaluation has been performed for a uniform magnetic field at 60 Hz. Comparisons of all dosimetric metrics computed in each particular model agree within 2% or less. Since in situ measurements cannot be performed in humans, and achievable accuracy of measurements in models and animals is not likely to be better than 10-15%, the comparisons presented should provide confidence limits on computational dosimetry. An evaluation of the effect of model size, shape and resolution has also been performed and further illuminated the reasons for differences in induced electric fields for various human body models.

  6. Regularly scheduled, day-time, slow-onset 60 Hz electric and magnetic field exposure does not depress serum melatonin concentration in nonhuman primates

    SciTech Connect

    Rogers, W.R.; Smith, H.D.; Orr, J.L.; Reiter, R.J.; Barlow-Walden, L.

    1995-12-31

    Experiments conducted with laboratory rodents indicate that exposure to 60 Hz electric fields or magnetic fields can suppress nocturnal melatonin concentrations in pineal gland and blood. In three experiments employing three field-exposed and three sham-exposed nonhuman primates, each implanted with an indwelling venous cannula to allow repeated blood sampling, the authors studied the effects of either 6 kV/m and 50 {micro}T (0.5 G) or 30 kV/m and 100 {micro}T (1.0 G) on serum melatonin patterns. The fields were ramped on and off slowly, so that no transients occurred. Extensive quality control for the melatonin assay, computerized control and monitoring of field intensities, and consistent exposure protocols were used. No changes in nocturnal serum melatonin concentration resulted from 6 weeks of day-time exposure with slow field onset/offset and a highly regular exposure protocol. These results indicate that, under the conditions tested, day-time exposure to 60 Hz electric and magnetic fields in combination does not result in melatonin suppression in primates.

  7. Assessment of genetic damage in peripheral blood of human volunteers exposed (whole-body) to a 200 muT, 60 Hz magnetic field.

    PubMed

    Albert, Genevieve C; McNamee, James P; Marro, Leonora; Bellier, Pascale V; Prato, Frank S; Thomas, Alex W

    2009-02-01

    To investigate the extent of damage in nucleated cells in peripheral blood of healthy human volunteers exposed to a whole-body 60 Hz, 200 microT magnetic field. In this study, 10 male and 10 female healthy human volunteers received a 4 h whole-body exposure to a 200 microT, 60 Hz magnetic field. In addition, five males and five females were treated in a similar fashion, but were exposed to sham conditions. For each subject, a blood sample was obtained prior to the exposure period and aliquots were used as negative- (pre-exposure) and positive- [1.5 Gray (Gy) (60)Cobalt ((60)Co) gamma-irradiation] controls. At the end of the 4 h exposure period, a second blood sample was obtained. The extent of DNA damage was assessed in peripheral human blood leukocytes from all samples using the alkaline comet assay. To detect possible clastogenic effects, the incidence of micronuclei was assessed in phytohemagglutinin (PHA)-stimulated lymphocytes using the cytokinesis-block micronucleus assay. There was no evidence of either increased DNA damage, as indicated by the alkaline comet assay, or increased incidence of micronuclei (MN) in the magnetic field exposed group. However, an in vitro exposure of 1.5 Gy gamma-irradiation caused a significant increase in both DNA damage and MN induction. This study found no evidence that an acute, whole-body exposure to a 200 microT, 60 Hz magnetic field for 4 hours could cause DNA damage in human blood.

  8. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates

    SciTech Connect

    Rhodes, J.W.

    1992-07-14

    This volume contains detailed experimental data to accompany quarterly report, dated July 14, 1992, by this group entitled Investigation of Effects of 60-Hz Electric Fields on Operant and Social Behavior and on the Neuroendocrine System of Nonhuman Primates.'' This volume is a collection of Appendices which are entitled: Appendix A- Field Mapping Data Forms, Appendix B- Exposure Area (East Side) Electric Field Data, Appendix C- Exposure Area (East Side) Magnetic Field Data, Appendix D- Sham Area (West Side) Magnetic Field Data, Appendix E- Memoranda Concerning Field Onset During Experiment IV and the Crossover Experiment, Appendix F- Exposure Area (East Side) Electric Field Data, Appendix G- Exposure Area (East Side) Magnetic Field Data, Appendix H- Sham Area (west Side) Magnetic Field Data, Appendix I- Compiled Data and Anovas for Experiment III Social Data, Appendix J -Written Comments Provided by Statistician Dr. Robert Mason, and Appendix K- Reference Text Provided by Dr. Coelho.

  9. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates

    SciTech Connect

    Rogers, W.R.; Rhodes, J.W.

    1992-09-01

    A cohort of sixteen male baboons were assigned to electric and magnetic field (E/MF) exposure and sham-exposure. The social behavior subjects were simultaneously exposed to 60 Hz E/MF. Ten behavioral categories were measured. Each behavioral category was comprised of multiple molecular behaviors that could be objectively identified and counted. Six of the behavior categories were social'', in that interactions between subjected were involved. The remaining four were non-social'' and pertained to individual behaviors such as movements or postural stances.

  10. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates

    SciTech Connect

    Orr, J.L.

    1989-10-01

    The objective of this program is to investigate, using the baboon as a nonhuman primate surrogate for the human, behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields. Results from this program could be used to estimate and evaluate the likelihood of deleterious consequences resulting from exposure of humans to the electric and magnetic fields associated with electric power transmission. This program is being conducted at Southwest Research Institute (SwRI) as part of an international collaborative information exchange and scientific research effort. This annual report marks the completion of the first year of the four year research program. This project year has focused on two technical areas: the modification of the facility to include 60-Hz magnetic fields, and development of the capability for studies of neuroendocrine parameters by obtaining blood samples from baboons during electric and magnetic field exposure. Activities in the social behavior, operant behavior, and laboratory animal sciences during this project year have been in preparation for the start of Experiment 3. 7 figs., 10 tabs.

  11. 60 Hz electric field changes the membrane potential during burst phase in pancreatic β-cells: in silico analysis.

    PubMed

    Neves, Gesilda F; Silva, José R F; Moraes, Renato B; Fernandes, Thiago S; Tenorio, Bruno M; Nogueira, Romildo A

    2014-06-01

    The production, distribution and use of electricity can generate low frequency electric and magnetic fields (50-60 Hz). Considering that some studies showed adverse effects on pancreatic β-cells exposed to these fields; the present study aimed to analyze the effects of 60 Hz electric fields on membrane potential during the silent and burst phases in pancreatic β-cells using a mathematical model. Sinusoidal 60 Hz electric fields with amplitude ranging from 0.5 to 4 mV were applied on pancreatic β-cells model. The sinusoidal electric field changed burst duration, inter-burst intervals (silent phase) and spike sizes. The parameters above presented dose-dependent response with the voltage amplitude applied. In conclusion, theoretical analyses showed that a 60 Hz electric field with low amplitudes changes the membrane potential in pancreatic β-cells.

  12. Exposure of baboons to combined 60 Hz electric and magnetic fields does not produce work stoppage or affect operant performance on a match-to-sample task

    SciTech Connect

    Orr, J.L.; Rogers, W.R.; Smith, H.D.

    1995-12-31

    The authors examined the effects of combined 60 Hz electric and magnetic field (EMF) exposure on performance of delayed match-to-sample (MTS) procedure involving the flash rate of a light as the stimulus. Six baboons (Papio cynocephalus) fully acquired the task; four others functioned accurately only when cued. All ten subjects were assigned to EMF-exposed or sham-exposed groups of five and were used to test for a work-stoppage effect that was previously observed with initial exposure to electric fields (EF) of 30 or 60 kV/m. Here, the authors report the results of two experiments, each consisting of 6 week preexposure, exposure, and postexposure periods. They found no evidence of work stoppage with fields of 6 kV/m and 50 {micro}T (0.5 G) or with 30 kV/m and 100 {micro}T (1.0 G). In neither experiment was there evidence of an adverse effect of 60 Hz EMF exposure on MTS performance.

  13. Rapid-onset/offset, variably scheduled 60 Hz electric and magnetic field exposure reduces nocturnal serum melatonin concentration in nonhuman primates

    SciTech Connect

    Rogers, W.R.; Smith, H.D.; Reiter, R.J.; Barlow-Walden, L.

    1995-12-31

    Experiments with rodents indicate that power-frequency electric field (EF) or magnetic field (MF) exposure can suppress the normal nocturnal increase in melatonin concentration in pineal gland and blood. In a separate set of three experiments conducted with nonhuman primates, the authors did not observe melatonin suppression as a result of 6 weeks of day-time exposure to combined 60 Hz electric and magnetic fields (E/MF) with regularly schedule ``slow`` E/MF onsets/offsets. The study described here used a different exposure paradigm in which two baboons were exposed to E/MF with ``rapid`` E/MF onsets/offsets accompanied by EF transients not found with slowly ramped E/MF onset/offset; profound reductions in nocturnal serum melatonin concentration were observed in this experiment. If replicated in a more extensive experiment, the observation of melatonin suppression only in the presence of E/MF transients would suggest that very specific exposure parameters determine the effects of 60 Hz E/MF on melatonin.

  14. Absence of DNA damage after 60-Hz electromagnetic field exposure combined with ionizing radiation, hydrogen peroxide, or c-Myc overexpression.

    PubMed

    Jin, Yeung Bae; Choi, Seo-Hyun; Lee, Jae Seon; Kim, Jae-Kyung; Lee, Ju-Woon; Hong, Seung-Cheol; Myung, Sung Ho; Lee, Yun-Sil

    2014-03-01

    The principal objective of this study was to assess the DNA damage in a normal cell line system after exposure to 60 Hz of extremely low frequency magnetic field (ELF-MF) and particularly in combination with various external factors, via comet assays. NIH3T3 mouse fibroblast cells, WI-38 human lung fibroblast cells, L132 human lung epithelial cells, and MCF10A human mammary gland epithelial cells were exposed for 4 or 16 h to a 60-Hz, 1 mT uniform magnetic field in the presence or absence of ionizing radiation (IR, 1 Gy), H(2)O(2) (50 μM), or c-Myc oncogenic activation. The results obtained showed no significant differences between the cells exposed to ELF-MF alone and the unexposed cells. Moreover, no synergistic or additive effects were observed after 4 or 16 h of pre-exposure to 1 mT ELF-MF or simultaneous exposure to ELF-MF combined with IR, H(2)O(2), or c-Myc activation.

  15. Effect of 60 Hz magnetic fields on the activation of hsp70 promoter in cultured INER-37 and RMA E7 cells.

    PubMed

    Heredia-Rojas, J Antonio; Rodríguez de la Fuente, Abraham Octavio; Alcocer González, Juan Manuel; Rodríguez-Flores, Laura E; Rodríguez-Padilla, Cristina; Santoyo-Stephano, Martha A; Castañeda-Garza, Esperanza; Taméz-Guerra, Reyes S

    2010-10-01

    It has been reported that 50-60 Hz magnetic fields (MF) with flux densities ranging from microtesla to millitesla are able to induce heat shock factor or heat shock proteins in various cells. In this study, we investigated the effect of 60 Hz sinusoidal MF at 8 and 80 μT on the expression of the luciferase gene contained in a plasmid labeled as electromagnetic field-plasmid (pEMF). This gene construct contains the specific sequences previously described for the induction of hsp70 expression by MF, as well as the reporter for the luciferase gene. The pEMF vector was transfected into INER-37 and RMA E7 cell lines that were later exposed to either MF or thermal shock (TS). Cells that received the MF or TS treatments and their controls were processed according to the luciferase assay system for evaluate luciferase activity. An increased luciferase gene expression was observed in INER-37 cells exposed to MF and TS compared with controls (p < 0.05), but MF exposure had no effect on the RMA E7 cell line.

  16. (Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates)

    SciTech Connect

    Orr, J.L.

    1989-03-24

    The objective of this program is to investigate, using the baboon as a nonhuman primate surrogate for the human, behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields. Results from this program, along with information from experiments conducted elsewhere, could be used to estimate and evaluate the likelihood of deleterious consequences resulting from exposure of humans to the electric and magnetic fields associated with electric power transmission. The test facility is being modified to include combined electric and magnetic field capability. This will be accomplished by the installation of a magnetic field exposure system and modification of the electric field exposure equipment. The purpose of this document is to provide information on the design. 14 figs., 5 tabs.

  17. Effects of 60-Hz electric and magnetic fields on operant and social behavior and on nueroendocrine system of nonhuman primates

    SciTech Connect

    Rogers, W.R.

    1993-01-22

    This series of experiments, using a well-characterized exposure facility and employing a variety of control procedures to study behavior and the neuroendocrine system of nonhuman primates, does not provide any evidence that exposure to power-frequency electric fields, or electric and magnetic fields in combination, for 12 hours per day for six weeks produces any deleterious effects in young-adult males. The primate experiments summarized here confirm the general conclusion indicated by experiments with rodents; although biological and behavioral changes can occur, there are no clear results establishing the occurrence of adverse effects in experiments involving relatively short-term exposure to environmentally-relevant electric or magnetic fields. Given the general agreement of the primate and rodent results, conclusions from the laboratory animal studies therefore presumably generalize well to humans.

  18. Reduction of the nocturnal rise in pineal melatonin levels in rats exposed to 60-Hz electric fields in utero and for 23 days after birth

    SciTech Connect

    Reiter, R.J.; Anderson, L.E.; Buschbom, R.I.; Wilson, B.W.

    1988-02-01

    Rats exposed to 60-Hz electric fields of either 10, 65, or 130 kV/m from conception to 23 days of age exhibited reduced peak nighttime pineal melatonin contents compared to unexposed controls. As a group, the exposed rats also exhibited a phase delay, estimated at approximately 1.4 hours, in the occurrence of the nocturnal melatonin peak. No clear dose-response relationship was noticed over the range of electric field strengths used as treatments in these experiments. These are the first studies concerned with the effects of electric field exposure on the pineal melatonin rhythm in immature rats and the findings are generally consistent with those obtained using adult rats, where electric field exposure has been shown to abolish the nighttime rhythm in pineal melatonin concentrations. 15 refs., 1 fig., 1 tab.

  19. Reduction of the nocturnal rise in pineal melatonin levels in rats exposed to 60-Hz electric fields in utero and for 23 days after birth

    SciTech Connect

    Reiter, R.J.; Anderson, L.E.; Buschbom, R.L.; Wilson, B.W.

    1988-01-01

    Rats exposed to 60-Hz electric fields of either 10, 65, or 130 kV/m from conception to 23 days of age exhibited reduced peak nighttime pineal melatonin contents compared to unexposed controls. As a group, the exposed rats also exhibited a phase delay, estimated at approximately 1.4 hours, in the occurrence of the nocturnal melatonin peak. No clear dose-response relationship was noticed over the range of electric field strengths used as treatments in these experiments. These are the first studies concerned with the effects of electric field exposure on the pineal melatonin rhythm in immature rats. The findings are generally consistent with those obtained using adult rats, where electric field exposure has been shown to abolish the nighttime rhythm in pineal melatonin concentrations.

  20. (Study of the behavioral and biological effects of high intensity 60 Hz electric fields): Quarterly technical progress report No. 29

    SciTech Connect

    Orr, J.L.

    1989-07-14

    Activities this quarter involved all phases of the project plus a meeting of the Joint Committee in Tokyo. Detailed mapping of the exposure facility is scheduled to be completed during the week of August 14, 1989. Both electric and magnetic fields should be available for tests of the components of the tether and blood sampling system for the neuroendocrine pilot study in September 1989. The groups for the social behavior study are stabilizing appropriately. Details on the formation of the groups and their status has been provided. Dr. Coelho has included information related to aspects of the social experiment ranging from age estimation in baboons through the cardiovascular consequences of psychosocial stress. In addition, a draft manuscript is included on the data from the previous experiments which describes the effects of 30 and 60 kV/m electric fields on the social behavior of baboons. Tests of the blood handling procedures and analysis methods have been completed. With the exception of the catecholamine analyses, the handling procedures and variability in replicate measurements are satisfactory. Logistic and practical considerations now weigh strongly against including the analysis of the blood samples for catecholamines. Preliminary tests indicate that a sampling procedure which will work for the other compounds is probably not satisfactory for the catecholamines.

  1. Effects of concurrent exposure to 60 Hz electric and magnetic fields on the social behavior of baboons

    SciTech Connect

    Coelho, A.M. Jr.; Easley, S.P.; Rogers, W.R. |

    1995-12-31

    Previous research has demonstrated that 30 or 60 kV/m electric fields (EF) reliably produce temporary increases in the performance of three categories of baboon social behavior: Passive Affinity, Tension, and Stereotypy. The experimental design included 6 week preexposure, exposure, and postexposure periods with experimental and control groups, each with eight subjects. Here, the authors report two experiments that evaluated the effects of combined EF and magnetic fields (MF) on baboon social behavior. One experiment demonstrated that exposure to 6 kV/m EF and 50 {micro}T (0.5 G) MF produced Period {times} Group interactions for Stereotypy and Attack, but the previously observed increases in Passive Affinity, Tension, and Stereotypy did not occur. A second experiment demonstrated that exposure to 30 kV/m EF and 100 {micro}T 1.0 G MF did not produce the same magnitude of increases in Passive Affinity, Tension, and Stereotypy observed previously with 30 kV/m EF alone. The exposed group exhibited decreased performance rates for several behavior categories during exposure with further declines during postexposure. The control group showed fewer downward trends across periods.

  2. Protein kinase C activity is altered in HL60 cells exposed to 60 Hz AC electric fields

    SciTech Connect

    Holian, O.; Reyes, H.M.; Attar, B.M.; Walter, R.J.; Astumian, R.D.; Lee, R.C.

    1996-12-31

    The authors examined the effects of electric fields (EFs) on the activity and subcellular distribution of protein kinase C (PKC) of living HL60 cells. Sixty Hertz AC sinusoidal EFs (1.5--1,000 mV/cm p-p) were applied for 1 h to cells (10{sup 7}/ml) in Teflon chambers at 37 C in the presence or absence of 2 {micro}M phorbol 12-myristate 13-acetate (PMA). PMA stimulation alone evoked intracellular translocation of PKC from the cytosolic to particulate fractions. In cells that were exposed to EFs (100--1,000 mV/cm) without PMA, a loss of PKC activity from the cytosol, but no concomitant rise in particulate PKC activity, was observed. In the presence of PMA, EFs (33--330 mV/cm) also accentuated the expected loss of PKC activity from the cytosol and augmented the rise in PKC activity in the particulate fraction. These data show that EFs alone or combined with PMA promote down-regulation of cytosolic PKC activity similar to that evoked by mitogens and tumor promoters but that it does not elicit the concomitant rise in particulate activity seen with those agents.

  3. Are the stray 60-Hz electromagnetic fields associated with the distribution and use of electric power a significant cause of cancer?

    PubMed Central

    Jackson, J D

    1992-01-01

    The putative causal relation between ambient low-frequency (50 or 60 Hz) electromagnetic fields (necessarily present in living and working environments because of our ever increasing use of electrical devices) and cancer, especially leukemia, can be tested on the large scale by examining historical data on the growth of the generation and consumption of electric power since 1900 and corresponding data on cancer death and incidence rates. The United States per capita generation and residential consumption of electric power have grown roughly exponentially since 1900; total per capita generation has increased by a factor of 10 since 1940, and per capita residential consumption has increased by a factor of 20 in the same period. The ubiquitous stray fields from power distribution lines and internal and external wiring in buildings have grown in the same proportions. In contrast to the explosive increase in the generation and use of electricity, the age-adjusted cancer death rate for the population as a whole shows only a slight rise since 1900. When respiratory cancers (largely caused by tobacco use) are subtracted, the remaining death rate has actually fallen since 1940. That the death rate may have fallen because of better diagnosis and treatment, despite a rising incidence rate, is not substantiated, especially for leukemia, including childhood leukemia, where the incidence rate has been constant or declining slightly for the past 25 yr. The absence of any appreciable change in the national cancer incidence rates during a period in which residential use of electric power has increased dramatically shows that the associated stray 50- or 60-Hz electromagnetic fields pose no significant hazard to the average individual. PMID:1565645

  4. Are the stray 60-Hz electromagnetic fields associated with the distribution and use of electric power a significant cause of cancer?

    PubMed

    Jackson, J D

    1992-04-15

    The putative causal relation between ambient low-frequency (50 or 60 Hz) electromagnetic fields (necessarily present in living and working environments because of our ever increasing use of electrical devices) and cancer, especially leukemia, can be tested on the large scale by examining historical data on the growth of the generation and consumption of electric power since 1900 and corresponding data on cancer death and incidence rates. The United States per capita generation and residential consumption of electric power have grown roughly exponentially since 1900; total per capita generation has increased by a factor of 10 since 1940, and per capita residential consumption has increased by a factor of 20 in the same period. The ubiquitous stray fields from power distribution lines and internal and external wiring in buildings have grown in the same proportions. In contrast to the explosive increase in the generation and use of electricity, the age-adjusted cancer death rate for the population as a whole shows only a slight rise since 1900. When respiratory cancers (largely caused by tobacco use) are subtracted, the remaining death rate has actually fallen since 1940. That the death rate may have fallen because of better diagnosis and treatment, despite a rising incidence rate, is not substantiated, especially for leukemia, including childhood leukemia, where the incidence rate has been constant or declining slightly for the past 25 yr. The absence of any appreciable change in the national cancer incidence rates during a period in which residential use of electric power has increased dramatically shows that the associated stray 50- or 60-Hz electromagnetic fields pose no significant hazard to the average individual.

  5. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates

    SciTech Connect

    Smith, H.D.

    1992-11-02

    The objective of this program is to investigate behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields (E/MF), using the baboon surrogate for the human. Baboon social groups were scanned and electronically monitored during Experiments IV and IVA. The social scan, form that the technicians used to identify baboon locations and proximity to other baboons: was used to gain a simple snapshot of the position of the baboons in their cage. The scans were taken hourly every morning and evening for a total of eight scans per side per day. This report covers in detail the scan and activity data-gathering process. A set of appendices is attached which include printouts of the data sets and adjunct material pertinent to interpreting the data. The supporting material is comprised of calendars and listings of major events that occurred during the scan and activity data collection.

  6. Electric field of the power terrestrial sources observed by microsatellite Chibis-M in the Earth's ionosphere in frequency range 1-60 Hz

    NASA Astrophysics Data System (ADS)

    Dudkin, Fedir; Korepanov, Valery; Dudkin, Denis; Pilipenko, Vyacheslav; Pronenko, Vira; Klimov, Stanislav

    2015-07-01

    The power line emission (PLE) 50/60 Hz and the Schumann resonance (SR) harmonics were detected by the use of a compact electrical field sensor of length 0.42 m during microsatellite Chibis-M mission in years 2012-2014. The initial orbit of Chibis-M has altitude 500 km and inclination 52°. We present the space distribution of PLE and its connections with the possible overhead power lines. PLE has been recorded both in the shade and sunlit parts of the orbits as opposed to SR which have been recorded only in the nightside of the Earth. The cases of an extra long distance of PLE propagation in the Earth's ionosphere and increased value of SR Q factor have been also observed. These results should stimulate the ionosphere model refinement for ultralow frequency and extremely low frequency electromagnetic wave propagation as well as a study on new possibility of the ionosphere diagnostics.

  7. Experimental evidence for 60 Hz magnetic fields operating through the signal transduction cascade. Effects on calcium influx and c-MYC mRNA induction.

    PubMed

    Liburdy, R P; Callahan, D E; Harland, J; Dunham, E; Sloma, T R; Yaswen, P

    1993-11-22

    We tested the hypothesis that early alterations in calcium influx induced by an imposed 60 Hz magnetic field are propagated down the signal transduction (ST) cascade to alter c-MYC mRNa induction. To test this we measured both ST parameters in the same cells following 60 Hz magnetic field exposures in a specialized annular ring device (220 G (22 mT), 1.7 mV/cm maximal E(induced), 37 degrees C, 60 min). Ca2+ influx is a very early ST marker that precedes the specific induction of mRNA transcripts for the proto-oncogene c-MYC, an immediate early response gene. In three experiments influx of 45Ca2+ in the absence of mitogen was similar to that in cells treated with suboptimal levels of Con-A (1 micrograms/ml). However, calcium influx was elevated 1.5-fold when lymphocytes were exposed to Con-A plus magnetic fields; this co-stimulatory effect is consistent with previous reports from our laboratory [FEBS Lett. 301 (1992) 53-59; FEBS Lett. 271 (1990) 157-160; Ann. N.Y. Acad. Sci. 649 (1992) 74-95]. The level of c-MYC mRNA transcript copies in non-activated cells and in suboptimally-activated cells was also similar, which is consistent with the above calcium influx findings. Significantly, lymphocytes exposed to the combination of magnetic fields plus suboptimal Con-A responded with an approximate 3.0-fold increase in band intensity of c-MYC mRNA transcripts. Importantly, transcripts for the housekeeping gene GAPDH were not influenced by mitogen or magnetic fields. We also observed that lymphocytes that failed to exhibit increased calcium influx in response to magnetic fields plus Con-A, also failed to exhibit an increase in total copies of c-MYC mRNA. Thus, calcium influx and c-MYC mRNA expression, which are sequentially linked via the signal transduction cascade in contrast to GAPDH, were both increased by magnetic fields. These findings support the above ST hypothesis and provide experimental evidence for a general biological framework for understanding magnetic field

  8. Increased mortality in land snails (Cepaea nemoralis) exposed to powerline (60-Hz) magnetic fields and effects of the light-dark cycle.

    PubMed

    Ossenkopp, K P; Kavaliers, M; Lipa, S

    1990-06-22

    The effects of various durations (0.5, 2, 12, 48, or 120 h) of day- and night-time exposures to a 1.0 gauss (rms) 60-Hz magnetic field or sham field on mortality levels in the nocturnally-crepuscularly active land snail, Cepaea nemoralis, were examined. These snails were injected with morphine or saline vehicle and tested for reaction to an aversive thermal stimulus as part of another study. Mortality levels were monitored over a 2-week period following the initial exposure to the fields and were shown not to be differentially affected by the drug injection procedures. Mortality levels increased linearly as a function of increased length of exposure to the magnetic fields (P less than 0.001) but not when exposed to the sham fields. As well, night-time exposures resulted in greater mortality levels than day-time exposures (P less than 0.025). These results indicate that day-night rhythms are important in determining the magnitude of the magnetic field exposure effect. It is speculated that the magnetic fields may disrupt endogenous opioid- and calcium-modulated homeostatic mechanisms and augment stress effects, modifying a variety of systems including immunocompetence.

  9. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates

    SciTech Connect

    Rhodes, J.W.

    1992-07-14

    The objective of this program is to investigate behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields, using the baboon (Papio cynocephalus). Results from this program are used to estimate consequences of human exposure to the electric and magnetic fields associated with electric power transmission. Electric and magnetic field measurements for Experiment IIIA (Confirmatory), Experiment IV and Social Behavior portion of Experiment III are presented. The systems for the production and monitoring of the fields performed satisfactorily during Experiment IIIA and during all but the last part of Experiment IV. In Experiment III, two-way repeated analyses of variance revealed statistically significant Group (Exposed and Sham Exposed) and Period (Baseline. Exposure, and Post-Exposure) main effects. Two significant Period by Group interactions were also found. Seven of the ten behavioral categories showed a main effect of Period. Two-sample t-test comparisons of the two groups for each period indicated that performance rates in two behavioral categories (Stereotypy and Posture) were significantly lower in the Exposure Group. In general, the Exposed subjects exhibited a trend of progressively lower performance rates across the three periods. Specific accomplishments reported in this document were: measurement of electric and magnetic fields for Experiments IIIA and IV, completed analysis of the Social Behavioral data from Experiment III, and a detailed discussion of statistical methods employed on the Social Behavioral portion of Experiment III, and hematology data were collected and recorded for Operant and Social Behavioral subjects for Experiment IV.

  10. Non-Hodgkin's lymphoma among electric utility workers in Ontario: the evaluation of alternate indices of exposure to 60 Hz electric and magnetic fields.

    PubMed

    Villeneuve, P J; Agnew, D A; Miller, A B; Corey, P N

    2000-04-01

    To examine associations between non-Hodgkin's lymphoma (NHL) and exposures to 60 Hz magnetic and electric fields in electric utility workers with a series of indices that capture a variety of aspects of field strength. The study population consisted of 51 cases of NHL and 203 individually matched controls identified from within a cohort of male electric utility workers in Ontario. Odds ratios were calculated for several exposure indices with conditional logistic regression models. Aspects of exposure to electric and magnetic fields that were modelled included: the percentage of time spent above selected threshold field intensities, mean transitions in field strength, SD, and the arithmetic and geometric mean field intensities. For the most part, there was a lack of an association between exposure indices of magnetic fields and the incidence of NHL. Subjects in the upper tertile of percentage of time spent above electric field intensities of 10 and 40 V/m had odds ratios of 3.05 (95% confidence interval (95% CI) 1. 07 to 8.80) and 3.57 (1.30 to 9.80), respectively, when compared with those in the lowest tertile. Moreover, the percentages of time spent above these electric field thresholds were significant predictors of case status over and above the association explained by duration of employment and the arithmetic or geometric mean exposure. These data suggest that exposures above electric field threshold intensities of 10 and 40 V/m are important predictors of NHL. Consequently, the findings support the hypothesis that electric fields may play a promoting part in the aetiology of this cancer. Further occupational studies that include assessment of exposure to electric fields and measures of field strength above similar threshold cut off points are needed to confirm these findings.

  11. Evaluation of the possible copromoting effect of a 60 Hz magnetic field during chemically induced carcinogenesis in skin of SENCAR mice. Final report

    SciTech Connect

    DiGiovanni, J.; Walborg, E.F.; Anderson, L.E.; Sasser, L.B.; Morris, J.E.; Miller, D.L. |

    1997-11-01

    It has been hypothesized that exposure to extremely low frequency (ELF) magnetic fields can enhance tumorigenesis through a copromotional mechanism. Equivocal support for this hypothesis was provided by experiments performed by Stuchly et al. using a mouse skin model; i.e. the induction of skin tumors in SENCAR mice exposed to a single subcarcinogenic dose of 7,12-dimethylbenz(a)anthracene (DMBA) and promotion by repetitive doses of 12-O-tetradecanoylphorbol-13-acetate (TPA). The mice were exposed to a 2 mT (60 Hz) magnetic field during the entire promotion phase of the experiment. The Stuchly study, which utilized single weekly doses of TPA, demonstrated a statistically significant increase in skin tumors after 16--18 weeks of promotion; however, by 23 weeks of promotion, the difference was not statistically significant. The study was designed to provide definitive evidence to confirm or refute a copromotional role of ELF magnetic field exposure on DMBA/TPA-induced skin carcinogenesis in SENCAR mice. This study was modeled after the study of Stuchly et al., (1992), including the animal model and exposure conditions. However, three different promoting doses of TPA, within the linear dose response range for induction of skin tumors, were utilized.

  12. Chronically indwelling venous cannula and automatic blood sampling system for use with nonhuman primates exposed to 60 Hz electric and magnetic fields

    SciTech Connect

    Rogers, W.R.; Lucas, J.H.; Smith, H.D.; Orr, J.L.; Mikiten, B.C.

    1995-12-31

    An automated blood sampling system was developed for use with tethered baboons (Papio cynocephalus) during concurrent exposure to 60 Hz 30 kV/m electric fields and 0.1 mT (1.0 G) magnetic fields. The system was controlled by a FORTH-based microcomputer, which operated a pump, a fraction collector, and two pinch valves. A swivel mechanism at the end of the tether allowed the baboons to move freely in their cages. The hardware and software were designed for fail-safe operation. Heparinized saline was infused at a rate of 0.5 ml/min until a sample cycle was initiated. Then, blood was drawn from the animal into a storage tube at a rate of 12.5 ml/min, a sample of undiluted blood was taken from the end of the storage tube near the baboon, and the blood remaining in the storage tube was then flushed back into the animal. Use of the storage tube prevented the peristaltic pump rollers from pressing on tubing containing blood, and return of the blood diluted with saline limited the blood wasted per sample to less than 0.5 ml. The system functioned reliably in three experiments, collecting samples as scheduled 97% of the time. Although it was initially designed for and used successfully with primates in an electric and magnetic field environment, this type of system could be employed in many areas of biomedical research or medical treatment.

  13. Initial studies on the effects of combined 60 Hz electric and magnetic field exposure on the immune system of nonhuman primates

    SciTech Connect

    Murthy, K.K.; Rogers, W.R.; Smith, H.D.

    1995-12-31

    In a pilot immunology experiment, peripheral blood samples from six baboons (Papio cynocephalus) housed as a social group were collected during week 5 of preexposure, exposure, and postexposure periods that were each 6 weeks in duration. The subjects were exposed to vertical 6 kV/m and horizontal 50 {micro}T (0.5 G) fields for 12 h per day. Lymphocytes collected during the exposure period displayed statistically significant (P < .05) reductions in CD3{sup +} and CD4{sup +} counts, interleukin 2 receptor expression, and proliferative response to pokeweed mitogen. A second experiment was conducted using samples from seven subjects exposed to 30 kV/m and 100 {micro}T (1.0 G) and eight sham-exposed subjects. Statistically significant Period {times} Group interactions occurred for total white blood cell count and CD4{sup +} to CD8{sup +} ratio, but the pattern of results was not suggestive of an exposure-related effect. Although components of the nonhuman primate immune system appear to be affected by 60 Hz electric and magnetic field exposure in one of two experiments, additional experiments are required to evaluate this possibility.

  14. Influence of a 60 Hz, 3 microT, electromagnetic field on the reflex maturation of Wistar rats offspring from mothers fed a regional basic diet during pregnancy.

    PubMed

    Anselmo, Caroline W S F; Santos, Ana A A; Freire, Conciana M A; Ferreira, Lúcia M P; Cabral Filho, José E; Catanho, Maria Teresa J A; Medeiros, Maria Do Carmo

    2006-01-01

    The aim of the present study was to observe how the exposition of the pregnant rats to the electromagnetic field (EMF), with frequency of 60 Hz, magnetic field of 3 microT for 2 h per day and/or using the so-called regional basic diet (RBD) influenced the reflex maturation in their offspring. Four groups were formed: Group A (casein), B (casein and EMF), C (RBD) and D (RBD and EMF). The diet manipulation occurred during the pregnancy. The reflexes--assessed daily between 12:00 and 14:00--were: palm grasp (PG), righting reflex (RR), cliff avoidance (CA), vibrissae placing (VP), negative geotaxis (NG), auditory startle (AS) and free-fall righting (FFR). The association between EMF and deficient diet caused a delay in all reflexes when compared with Group A. When the diets were compared with both groups exposed to EMF, the delay occurred in the RR, VP, NG and CA in Group D. In the Groups C and A, the delay was observed in RR, CA, VP, NG, AS and PG. In relation to the EMF, Group B differed from Group A in CA, AS, FFR and PG and Group D differed from C in the PG. In conclusion, all the reflexes studied in this research were delayed by the association of the EMF with undernutrition during pregnancy.

  15. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates. Quarterly report 40, Operant behavior: Experiments 3, 4, and 4A

    SciTech Connect

    Rhodes, J.W.

    1992-09-24

    The objective of this program is to investigate behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields (E/MF), using the baboon (Papio cynocephalus) as a nonhuman primate surrogate for the human. Results from this program, along with information from experiments conducted elsewhere, could be used to estimate and evaluate the likelihood of deleterious consequences of human exposure to the electric and magnetic fields associated with electric power transmission. This report covers a series of three experiments (Experiments III, IV, and IVA) on the effect of combined 60-Hz E/MF on operant behavior. These experiments were a continuation of previous investigations of 60-Hz electric field exposure on baboons.

  16. Initial exposure to 30 kV/m or 60 kV/m 60 Hz electric fields produces temporary cessation of operant behavior of nonhuman primates

    SciTech Connect

    Rogers, W.R.; Orr, J.L.; Smith, H.D.

    1995-12-31

    In two separate experiments, the authors examined the effects of a 60 Hz electric field (EF) on performance of an operant schedule consisting of two signaled components: fixed-ratio (FR30) and differential reinforcement of low-rate (DRL20). In each experiment, 12 naive baboons (Papio cynocephalus) were assigned randomly to either an EF-exposed experimental group or a sham-exposed control group. A homogeneous vertical EF of 30 kV/m was used in one experiment; 60 kV/m was used in the other. The experimental design for both experiments included 6 week preexposure, exposure, and postexposure periods. The planned analyses indicated no evidence of statistically significant (P < .05) effects of EF exposure. However, exploratory analyses comparing performance during the last week of preexposure and the first week of exposure revealed statistically significant acute effects (work stoppage): The mean response rates of the EF-exposed groups were greatly reduced on day 1 of exposure but were normal by the end of day 2 of EF exposure. The authors hypothesize that introduction of a highly unusual stimulus, the EF, temporarily interfered with normal operant behavior to produce a primary work stoppage. Supplementary cross-over experiments added at the end of each main experiment indicated that work stoppage occurred again when formerly EF-exposed subjects served as sham-exposed controls, while other subjects received their first EF exposure. Presumably, reoccurrence of other stimuli correlated with initial exposure to the EF became sufficient to subsequently cause secondary work stoppage in the absence of direct EF exposure. The primary and secondary work-stoppage effects were reproducible.

  17. Ntp technical report on toxicity, reproductive, and developmental studies of 60-Hz magnetic fields, administered by whole body exposure to F344/N rats, Sprague-Dawley rats, and B6C3F1 mice. Toxicity report series

    SciTech Connect

    Boorman, G.A.

    1996-09-01

    Electric and magnetic fields are associated with the production, transmission, and use of electricity; thus the potential for human exposure is high. These electric and magnetic fields are predominantly of low frequency (60 Hz) and generally of low intensity. The prevailing view among physicists is that exposure to these low-frequency, low-intensity fields does not pose a health hazard. However, this view has been challenged by reports linking magnetic field exposure to the development of leukemia and other cancers. Because multiple epidemiologic studies suggested a potential for increased cancer rates with increasing exposure, and because of public concern, the effects of 60-Hz magnetic field exposure were examined in F344/N rats and B6C3F1 mice in 8-week full-body-exposure studies. Animals were evaluated for hematology and clinical chemistry (rats only) parameters, pineal gland hormone concentrations, and histopathology. Additional studies were performed in Sprague-Dawley rats to examine teratologic and reproductive effects of magnetic field exposure.

  18. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates. Quarterly report 37 - Part 2, Appendices

    SciTech Connect

    Rhodes, J.W.

    1992-07-14

    This volume contains detailed experimental data to accompany quarterly report, dated July 14, 1992, by this group entitled ``Investigation of Effects of 60-Hz Electric Fields on Operant and Social Behavior and on the Neuroendocrine System of Nonhuman Primates.`` This volume is a collection of Appendices which are entitled: Appendix A- Field Mapping Data Forms, Appendix B- Exposure Area (East Side) Electric Field Data, Appendix C- Exposure Area (East Side) Magnetic Field Data, Appendix D- Sham Area (West Side) Magnetic Field Data, Appendix E- Memoranda Concerning Field Onset During Experiment IV and the Crossover Experiment, Appendix F- Exposure Area (East Side) Electric Field Data, Appendix G- Exposure Area (East Side) Magnetic Field Data, Appendix H- Sham Area (west Side) Magnetic Field Data, Appendix I- Compiled Data and Anovas for Experiment III Social Data, Appendix J -Written Comments Provided by Statistician Dr. Robert Mason, and Appendix K- Reference Text Provided by Dr. Coelho.

  19. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates. Social behavior portions of Experiments III and IV: Quarterly report No. 39

    SciTech Connect

    Rogers, W.R.; Rhodes, J.W.

    1992-09-01

    A cohort of sixteen male baboons were assigned to electric and magnetic field (E/MF) exposure and sham-exposure. The social behavior subjects were simultaneously exposed to 60 Hz E/MF. Ten behavioral categories were measured. Each behavioral category was comprised of multiple molecular behaviors that could be objectively identified and counted. Six of the behavior categories were ``social``, in that interactions between subjected were involved. The remaining four were ``non-social`` and pertained to individual behaviors such as movements or postural stances.

  20. Effects of 60 Hz electric fields on operant and social stress behaviors of nonhuman primates. Annual report, August 5, 1984-October 25, 1985

    SciTech Connect

    Rogers, W.R.; Lucas, J.H.; Moore, G.T.; Orr, J.L.

    1985-01-01

    Operant behavioral methods have been used to assess the aversiveness of intense electric fields. One aspect of the aversiveness of a stimulus is the ability to act as a negative reinforcer. A negative reinforcer is a stimulus whose response contingent termination maintains behavior. Baboons were trained to perform an operant task to obtain food rewards, determined that the addition of an intense electric field did not disrupt performance, measured the background level of responding in the absence of any primary reinforcers, assessed the ability of electric field termination to maintain operant responding, and verified that the electric field could serve as a discriminative stimulus.

  1. Long-term effects of 60-Hz electric vs. magnetic fields on IL-1 and other immune parameters in sheep: Phase 4 study. Final report

    SciTech Connect

    Hefeneider, S.H.; McCoy, S.L.; Hausman, F.A.

    1998-10-01

    This study was designed to assess the effect of exposure to long-term low-frequency electric and magnetic fields (EMF) from an environmental 500-kV transmission line on immune function in sheep. The primary hypothesis tested was that the reduction in IL-1 activity observed in two previous short-term studies (9 months) was due to exposure to EMF from this transmission line. The secondary hypothesis was that long-term exposure (27 months) would impact immune function and animal health. To characterize the components of the EMF environment responsible for the previously observed reduction in IL-1 activity, the experiment was designed not only to examine the effect of exposure to electric and magnetic fields, but also to examine the magnetic field component alone. This was done by constructing a third pen (MF) which was shielded with wire to effectively eliminate the electric field while not significantly affecting the magnitude of the magnetic field.

  2. Residential exposures to indoor air pollutants could yield childhood leukemia risk levels similar to those associated with 60 Hz magnetic fields

    SciTech Connect

    Easterly, C.E.

    1992-12-31

    Over a decade ago Easterly suggested that electromagnetic fields may be able to participate in a cooperative process leading to the expression of cancer. Evidence derived from the literature is presented to support the suggestion that potentially cooperative factors other than electromagnetic fields are present in homes in sufficient quantities to result in approximately the same risk levels as are being measured in epidemiology studies of childhood leukemia and electromagnetic fields. Generally these odds ratios vary from 1.5 to 2.5.

  3. Residential exposures to indoor air pollutants could yield childhood leukemia risk levels similar to those associated with 60 Hz magnetic fields

    SciTech Connect

    Easterly, C.E.

    1992-01-01

    Over a decade ago Easterly suggested that electromagnetic fields may be able to participate in a cooperative process leading to the expression of cancer. Evidence derived from the literature is presented to support the suggestion that potentially cooperative factors other than electromagnetic fields are present in homes in sufficient quantities to result in approximately the same risk levels as are being measured in epidemiology studies of childhood leukemia and electromagnetic fields. Generally these odds ratios vary from 1.5 to 2.5.

  4. Effects of 60-Hz electric and magnetic fields on operant and social behavior and on neuroendocrine system of nonhuman primates. Draft final report, October 1, 1988--December 31, 1992

    SciTech Connect

    Rogers, W.R.; Coelho, A.M.; Easley, S.P.; Orr, J.L.; Reiter, R.J.; Rhodes, J.W.

    1992-09-24

    A series of pioneering electric and magnetic field experiments were completed using nonhuman primates and a unique, well-engineered, and reliable exposure facility. Effects of operant behavior, social behavior, and serum melatonin concentration were examined using 60 Hz field combinations of other 6 W/m and 0.6 G or 30 W/m and 1.0 G. Observations noted in the course of this study include: Combines electric and magnetic field exposure does not have any important effect on short-term memory; the transitory increases in social behavior observed in previous electric fields did not occur; combined electric and magnetic field exposure might lead to reduced behavioral frequency in baboon social groups; three experiments clearly establish that one set of exposure conditions does not produce molatonin suppression in nonhuman primates; and a small pilot experiment suggests that a different exposure protocol might result in melatonin suppression.

  5. Long-term effects of 60-Hz electric vs. magnetic fields on IL-1 and other immune parameters in sheep: Phase 5 study. Final report

    SciTech Connect

    Hefeneider, S.H.; McCoy, S.L.; Hausman, F.A.

    1998-10-01

    This study was designed to assess the effect of exposure to long-term low-frequency electric and magnetic fields (EMF) from a 500-kV transmission line on immune function in sheep. The primary hypothesis was that the reduction in IL-1 activity observed in two previous short-term studies (9 months) was due to EMF exposure from this transmission line. The secondary hypothesis was that long-term exposure (27 months) would impact immune function and animal health. To characterize the components of EMF responsible for the previously observed reduction in IL-1 activity, the experiment was designed not only to examine the effect of exposure to electric and magnetic fields, but also to examine the magnetic field component alone.

  6. Effects of 60-Hz electric and magnetic fields on operant and social behavior and on nueroendocrine system of nonhuman primates. Final report, October 1, 1988--December 31, 1992

    SciTech Connect

    Rogers, W.R.

    1993-01-22

    This series of experiments, using a well-characterized exposure facility and employing a variety of control procedures to study behavior and the neuroendocrine system of nonhuman primates, does not provide any evidence that exposure to power-frequency electric fields, or electric and magnetic fields in combination, for 12 hours per day for six weeks produces any deleterious effects in young-adult males. The primate experiments summarized here confirm the general conclusion indicated by experiments with rodents; although biological and behavioral changes can occur, there are no clear results establishing the occurrence of adverse effects in experiments involving relatively short-term exposure to environmentally-relevant electric or magnetic fields. Given the general agreement of the primate and rodent results, conclusions from the laboratory animal studies therefore presumably generalize well to humans.

  7. Effects of 60 Hz electric fields on operant and social stress behaviors of nonhuman primates. Technical status report, June 8-August 2, 1985

    SciTech Connect

    Not Available

    1985-08-02

    Progress made at calibrating the electric field distribution within and around cages used for behavorial testing of baboons is described. It is concluded that all of the parts of the ''system'' are rather constant in their readings. The only component which seems to show appreciable variability is the 4 cm probe. Although the optically coupled 4 cm spherical dipole probe usually performs well, it is becoming apparent that sometimes it can produce misleading results. Although we do not yet understand the situation completely, it appears as though there are at least two variables affecting the probe, battery voltage and humidity. 2 figs., 9 tabs.

  8. [The present state of knowledge concerning the effect of electromagnetic fields of 50/60 Hz on the circulatory system and the autonomic nervous system].

    PubMed

    Indulski, J A; Bortkiewicz, A; Zmyślony, M

    1997-01-01

    Diseases of the circulatory system together with neoplastic diseases are recognised as the major health problem in the contemporary world. Their origin and aggravation may be related to the exposure to electromagnetic fields (EMFs) since theoretically, disorders in the functioning of the circulatory system are most likely due to electric impulses generated in it by external magnetic fields. The nervous system, including its autonomic part which regulates, among others, the functioning of the circulatory system, because of its electric nature is another system which may be disturbed by EMFs. From the 1960s, biological studies on the effects of power-line frequency EMFs have been carried out in many countries. In view of the applied study model, four main directions of these studies can be identified: in vitro and in vivo animal experiments, experimental studies on humans, clinical and epidemiological studies. Experimental studies on animals and humans have yielded ambiguous and very often contradictory results. Some of them indicate that EMF contributes to slowing down the cardiac rhythm and the stroke volume of the left ventricle, other results suggest their acceleration, and still other show no differences. The results of clinical studies performed in many countries in different groups of workers exposed to power-line frequency EMFs have not produced the evidence for drawing unequivocal conclusions. Again some studies reveal that those exposed show disorders in neurovegetative and blood pressure regulations (hypotension or hypertension) as well as in cardiac rhythm (bradycardia or tachycardia). Other studies do not confirm harmful effect of EMF on the circulatory system. Therefore, it is not feasible to find out, on the basis of these studies, whether and how chronic exposure to power-line frequency EMFs influences the functioning of the circulatory system, the more so as ECG standard recording has been to date the only diagnostic method, and according to the

  9. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates: Neuroendocrine portion of Experiment IV

    SciTech Connect

    Rogers, W.R.; Rhodes, J.W.

    1992-08-31

    This quarterly report covers the neuroendocrine Portion of Experiment IV. Serum melatonin concentration was measured in individual baboons, each implanted with a chronically indwelling venous cannula. As in Experiment III the system of six automatic blood samplers was used to achieve undisturbed, 24 hr per day, simultaneous blood sampling from six individual subjects. The objective of the neuroendocrine portion of Experiment IV was to determine if 30 kV/m electric and 1.0 G magnetic field (E/MF) exposure produced a 50% decline in nocturnal serum melatonin concentration. Other groups of subjects were tested concurrently during Experiment IV to assess E/MF effects on group social and individual operant behavior. The results of these experiments will be covered respectively in the next two quarterly reports. The results of Experiment IV, as was the case with the result of Experiments III and IIIA, provide little or no evidence that E/MF exposure, under the conditions of these experiments, affects nocturnal serum melatonin concentrations of nonhuman primates. Together the negative results of Experiments III, IIA and IV indicate that day-time exposure of primates to slow-onset/offset, regularly-scheduled E/MF does not produce melatonin suppression, strongly suggesting that such exposure would not affect human melatonin either. However, before concluding that E/MF exposure in general has no effect on primate melatonin, nightime exposure needs to be examined, and the possibility, suggested by the Pilot Experiment, that fast onset/offset, irregularly-scheduled E/MF can completely suppress melatonin needs to be investigated.

  10. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates. Quarterly report 37 - Part 1, Text

    SciTech Connect

    Rhodes, J.W.

    1992-07-14

    The objective of this program is to investigate behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields, using the baboon (Papio cynocephalus). Results from this program are used to estimate consequences of human exposure to the electric and magnetic fields associated with electric power transmission. Electric and magnetic field measurements for Experiment IIIA (Confirmatory), Experiment IV and Social Behavior portion of Experiment III are presented. The systems for the production and monitoring of the fields performed satisfactorily during Experiment IIIA and during all but the last part of Experiment IV. In Experiment III, two-way repeated analyses of variance revealed statistically significant Group (Exposed and Sham Exposed) and Period (Baseline. Exposure, and Post-Exposure) main effects. Two significant Period by Group interactions were also found. Seven of the ten behavioral categories showed a main effect of Period. Two-sample t-test comparisons of the two groups for each period indicated that performance rates in two behavioral categories (Stereotypy and Posture) were significantly lower in the Exposure Group. In general, the Exposed subjects exhibited a trend of progressively lower performance rates across the three periods. Specific accomplishments reported in this document were: measurement of electric and magnetic fields for Experiments IIIA and IV, completed analysis of the Social Behavioral data from Experiment III, and a detailed discussion of statistical methods employed on the Social Behavioral portion of Experiment III, and hematology data were collected and recorded for Operant and Social Behavioral subjects for Experiment IV.

  11. Involvement of protein kinase C in the modulation of morphine-induced analgesia and the inhibitory effects of exposure to 60-hz magnetic fields in the land snail, Cepaea nemoralis

    SciTech Connect

    Kavaliers, M.; Ossenkopp, K.P. )

    1990-02-26

    One of the more consistent and dramatic effects of exposure to magnetic fields is the attenuation of morphine-induced analgesia. Results of previous studies have implicated alterations in calcium channel functioning and Ca{sup ++} flux in the mediation of these effects. It is generally accepted that Ca{sup ++}-activated-phospholipid-dependent protein kinase (Protein kinase C; PKC) plays an important role in relaying trans-membrane signaling in diverse Ca{sup ++} dependent cellular processes. In experiment 1 we observed that morphine-induced analgesia in the land snail, Cepaea nemoralis, as measured by the latency of an avoidance behavior to a warmed surface, was reduced by the PKC activator, SC-9, and was enhanced by the PKC inhibitors, H-7 and H-9. In contrast, HA-10004, a potent inhibitor of other protein kinases, but only a very weak inhibitor of PKC, had no effect on morphine-induced analgesia. In experiment 2 exposure of snails for 30 minutes to a 1.0 gauss (rms) 60-Hz magnetic field reduced morphine-induced analgesia. This inhibitory effect of the magnetic field was reduced by the PKC inhibitors, H-7 and H-9, and was augmented by the PKC activator SC-9. These results suggest that: (i) PKC is involved in the modulation of morphine-induced analgesia and, (ii) the inhibitory effects of magnetic fields involve PKC.

  12. Effects on g2/m phase cell cycle distribution and aneuploidy formation of exposure to a 60 Hz electromagnetic field in combination with ionizing radiation or hydrogen peroxide in l132 nontumorigenic human lung epithelial cells.

    PubMed

    Jin, Hee; Yoon, Hye Eun; Lee, Jae-Seon; Kim, Jae-Kyung; Myung, Sung Ho; Lee, Yun-Sil

    2015-03-01

    The aim of the present study was to assess whether exposure to the combination of an extremely low frequency magnetic field (ELF-MF; 60 Hz, 1 mT or 2 mT) with a stress factor, such as ionizing radiation (IR) or H2O2, results in genomic instability in non-tumorigenic human lung epithelial L132 cells. To this end, the percentages of G2/M-arrested cells and aneuploid cells were examined. Exposure to 0.5 Gy IR or 0.05 mM H2O2 for 9 h resulted in the highest levels of aneuploidy; however, no cells were observed in the subG1 phase, which indicated the absence of apoptotic cell death. Exposure to an ELF-MF alone (1 mT or 2 mT) did not affect the percentages of G2/M-arrested cells, aneuploid cells, or the populations of cells in the subG1 phase. Moreover, when cells were exposed to a 1 mT or 2 mT ELF-MF in combination with IR (0.5 Gy) or H2O2 (0.05 mM), the ELF-MF did not further increase the percentages of G2/M-arrested cells or aneuploid cells. These results suggest that ELF-MFs alone do not induce either G2/M arrest or aneuploidy, even when administered in combination with different stressors.

  13. Biomedical effects associated with energy-transmission systems: effects of 60-Hz electric fields on circadian and ultradian physiological and behavioral functions in small rodents. Period covered: January 1, 1980-December 31, 1980

    SciTech Connect

    Ehret, C.F.; Rosenberg, R.S.; Sacher, G.A.; Duffy, P.H.; Groh, K.R.; Russell, J.J.

    1980-01-01

    The effects of extremely low frequency (ELF) electric fields on transient patterns of circadian rhythms of physiological and behavioral end points are being investigated. This project is developing a data base to determine the exposure conditions that disturb the highly characteristic waveforms of ultradian, circadian, and infradian rhythms. The project has taken the following approach: (1) small rodents are exposed to well-defined ELF horizontal or vertical electric fields at nominal field strengths as high as 100 kV/m in individual residential facilities; (2) exposures follow a variety of schedules ranging from brief (one minute) to continuous, and including variations of circadian periodicities; (3) end points such as metabolism, activity, core body temperature, operant performance, and weight gain are continuously recorded for long intervals by microprocessor-controlled data acquisition systems; (4) the characteristic waveforms are analyzed by several statistical procedures for deviations from their unperturbed ultradian and circadian patterns; and (5) when and if exposures induce distrubances of the patterns, a search for concomitant neurochemical changes will begin. The following conclusions were reached: under a variety of exposure conditions the circadian regulatory system of the rat remained intact; brief ELF exposures at field strengths above 35 kV/m, presented during the inactive phase of the circadian cycle, produced a transient arousal in mice, characterized by increases in motor activity, carbon dioxide production, and oxygen consumption; the transient arousal habituated rapidly; no significant effects were seen in the second, third, or fourth exposure of mice using a one hour on, one hour off protocol; and there were no circadian aftereffects of the intermittent ELF stimulus in mice, based on measuresof rhythms of activity and gas metabolism.

  14. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates: Neuroendocrine portion of Experiment IV. Quarterly report No. 38

    SciTech Connect

    Rogers, W.R.; Rhodes, J.W.

    1992-08-31

    This quarterly report covers the neuroendocrine Portion of Experiment IV. Serum melatonin concentration was measured in individual baboons, each implanted with a chronically indwelling venous cannula. As in Experiment III the system of six automatic blood samplers was used to achieve undisturbed, 24 hr per day, simultaneous blood sampling from six individual subjects. The objective of the neuroendocrine portion of Experiment IV was to determine if 30 kV/m electric and 1.0 G magnetic field (E/MF) exposure produced a 50% decline in nocturnal serum melatonin concentration. Other groups of subjects were tested concurrently during Experiment IV to assess E/MF effects on group social and individual operant behavior. The results of these experiments will be covered respectively in the next two quarterly reports. The results of Experiment IV, as was the case with the result of Experiments III and IIIA, provide little or no evidence that E/MF exposure, under the conditions of these experiments, affects nocturnal serum melatonin concentrations of nonhuman primates. Together the negative results of Experiments III, IIA and IV indicate that day-time exposure of primates to slow-onset/offset, regularly-scheduled E/MF does not produce melatonin suppression, strongly suggesting that such exposure would not affect human melatonin either. However, before concluding that E/MF exposure in general has no effect on primate melatonin, nightime exposure needs to be examined, and the possibility, suggested by the Pilot Experiment, that fast onset/offset, irregularly-scheduled E/MF can completely suppress melatonin needs to be investigated.

  15. Investigation of effects of 60-Hz electric and magnetic fields on operant and social behavior and on the neuroendocrine system of nonhuman primates. Quarterly report, Scan and activity data for experiments 4 and 4A, [July 1, 1992--September 30, 1992

    SciTech Connect

    Smith, H.D.

    1992-11-02

    The objective of this program is to investigate behavioral and neuroendocrine effects associated with exposure to 60-Hz electric and magnetic fields (E/MF), using the baboon surrogate for the human. Baboon social groups were scanned and electronically monitored during Experiments IV and IVA. The social scan, form that the technicians used to identify baboon locations and proximity to other baboons: was used to gain a simple snapshot of the position of the baboons in their cage. The scans were taken hourly every morning and evening for a total of eight scans per side per day. This report covers in detail the scan and activity data-gathering process. A set of appendices is attached which include printouts of the data sets and adjunct material pertinent to interpreting the data. The supporting material is comprised of calendars and listings of major events that occurred during the scan and activity data collection.

  16. Improvement of both dystonia and tics with 60 Hz pallidal deep brain stimulation.

    PubMed

    Hwynn, Nelson; Tagliati, Michele; Alterman, Ron L; Limotai, Natlada; Zeilman, Pamela; Malaty, Irene A; Foote, Kelly D; Morishita, Takashi; Okun, Michael S

    2012-09-01

    Deep brain stimulation has been utilized in both dystonia and in medication refractory Tourette syndrome. We present an interesting case of a patient with a mixture of disabling dystonia and Tourette syndrome whose coexistent dystonia and tics were successfully treated with 60 Hz-stimulation of the globus pallidus region.

  17. Investigation of Potential Behavioral Effects of Exposure to 60 Hz Electromagnetic Fields.

    DTIC Science & Technology

    1985-12-01

    chlorpromazine was not altered by exposure to microwaves. A lhough, the above current literature indicates that under many con- ditions the effects of various...Oct 20-23, 1975, Vol. 1, DHEW Publ. ( FDA )77-8010, pp. 311-322, Washington, D.C.: U. S. Government Printing Office, 1975. % % 6. deLorge, J. Operant...In: Symposium on Biological Effects and Measurement of Radio Frequency/Microwaves, D. G. Hazzard (Ed.), pp. 62-68, HEW Publ ( FDA )77-8026, Washington

  18. Deficits in high- (>60 Hz) gamma-band oscillations during visual processing in schizophrenia

    PubMed Central

    Grützner, Christine; Wibral, Michael; Sun, Limin; Rivolta, Davide; Singer, Wolf; Maurer, Konrad; Uhlhaas, Peter J.

    2013-01-01

    Current theories of the pathophysiology of schizophrenia have focused on abnormal temporal coordination of neural activity. Oscillations in the gamma-band range (>25 Hz) are of particular interest as they establish synchronization with great precision in local cortical networks. However, the contribution of high gamma (>60 Hz) oscillations toward the pathophysiology is less established. To address this issue, we recorded magnetoencephalographic (MEG) data from 16 medicated patients with chronic schizophrenia and 16 controls during the perception of Mooney faces. MEG data were analysed in the 25–150 Hz frequency range. Patients showed elevated reaction times and reduced detection rates during the perception of upright Mooney faces while responses to inverted stimuli were intact. Impaired processing of Mooney faces in schizophrenia patients was accompanied by a pronounced reduction in spectral power between 60–120 Hz (effect size: d = 1.26) which was correlated with disorganized symptoms (r = −0.72). Our findings demonstrate that deficits in high gamma-band oscillations as measured by MEG are a sensitive marker for aberrant cortical functioning in schizophrenia, suggesting an important aspect of the pathophysiology of the disorder. PMID:23532620

  19. Aliasing of 60-Hz Artifact as a Result of Compressed Time Base.

    PubMed

    Bolen, Robert D; Edwards, Jonathan C; Halford, Jonathan J

    2017-09-01

    Digital EEG has brought about greater flexibility in data interpretation but has also resulted in new and unique artifacts. As digital EEG has evolved, an increase in intensive care unit monitoring has occurred, bringing more sources of artifact to light. Aliasing as a result of a combination of compressed time base and display monitor resolution can result in appearance of spurious waveforms that can potentially skew interpretation. A portion of a digital EEG from an intensive care unit patient acquired at a sample rate of 1,024 Hz was reviewed at a time base of 15 mm/second on a monitor with a resolution of 1,920 × 1,080. At a time base of 15 mm/second, a 60-Hz artifact resulted in the appearance of a 4-Hz delta artifact that resolved when the time base was changed to a more standard 30 mm/second. A software malfunction of the digital antialiasing filter for display resulted in the appearance of a novel 4-Hz artifact.

  20. Power line emission 50/60 Hz and Schumann resonances observed by microsatellite Chibis-M in the Earth's ionosphere

    NASA Astrophysics Data System (ADS)

    Dudkin, Denys; Pilipenko, Vyacheslav; Dudkin, Fedir; Pronenko, Vira; Klimov, Stanislav

    2015-04-01

    The overhead power lines are the sources of intense wideband electromagnetic (EM) emission, especially in ELF-VLF range, because of significant length (up to a few thousand kilometers) and strong 50/60 Hz currents with noticeable distortion. The radiation efficiency of the power line emission (PLE) increases with the harmonic order, so they are well observed by ground-based EM sensors. However their observations by low orbiting satellites (LEO) are very rare, particularly at basic harmonic 50/60 Hz, because of the ionospheric plasma opacity in ELF band. The Schumann resonance (SR) is the narrow-band EM noise that occurs due to the global thunderstorm activity in the Earth-ionosphere cavity. The first five eigenmodes of the SR are 7.8, 14.3, 20.8, 27.3 and 33.8 Hz and, thus, SR harmonics are also strongly absorbed by the Earth ionosphere. The published numerical simulations show that the penetration depth of such an ELF emission into the Earth's ionosphere is limited to 50-70 km for electric field and 120-240 km for magnetic field. From this follows, that PLE and SR can hardly ever be detected by LEO satellites, i.e. above the F-layer of ionosphere. In spite of this fact, these emissions were recently observed with use of the electric field antennas placed on the satellites C/NOFS (USA) and Chibis-M (Russia). Microsatellite Chibis-M was launched on January 24, 2012, at 23:18:30 UTC from the cargo ship "Progress M-13M" to circular orbit with altitude ~500 km and inclination ~52° . Chibis-M mass is about 40 kg where one third is a scientific instrumentation. The dimensions of the microsatellite case are 0.26x0.26x0.54 m with the outside mounted solar panels, service and scientific instrumentation. The main scientific objective of Chibis-M is the theoretical model verification for the atmospheric gamma-ray bursts. It requires the study of the accompanying EM processes such as the plasma waves produced by the lightning discharges in the VLF band. Chibis-M decayed on 15

  1. Effects of field-manure applications on stratified 17B-estradiol concentrations

    USDA-ARS?s Scientific Manuscript database

    The estrogenic hormone, 17'-estradiol (E2), is a potent endocrine disrupting compound found in animal manures. The objective of this study was to assess the occurrence of manure-borne E2 stratified through soil in fields that receive swine (Sus scrofa domestica) manure slurry as fertilizer. Soil cor...

  2. Ankle variability is amplified in older adults due to lower EMG power from 30-60 Hz.

    PubMed

    Kwon, MinHyuk; Baweja, Harsimran S; Christou, Evangelos A

    2012-12-01

    The purpose of this study was to determine the neuromuscular mechanisms of the involved muscles that contribute to the greater positional variability at the ankle joint in older adults compared with young adults. Eleven young adults (25.6±4.9 years) and nine older adults (76.9±5.9 years) were asked to accurately match and maintain a horizontal target line with 5° dorsiflexion of their ankle for 20 s. The loads were 5 and 15% of the one repetition maximum load (1 RM). The visual gain was kept constant at 1° for all trials. Positional variability was quantified as the standard deviation (SD) of the detrended position signal. The neural activation of the tibialis anterior and soleus muscles was quantified as the normalized EMG amplitude, power spectrum density (PSD; EMG oscillations) and coactivation of the two muscles. As expected, positional variability was greater in older adults (older: 0.11±0.06° vs. young: 0.04±0.02°; p=.003). The only significant neural difference occurred for the PSD of the tibialis anterior muscle, where young adults exhibited significantly greater power than older adults from 30-60 Hz. The amplified positional variability of ankle joint in older adults was associated with lower power from 30-60 Hz oscillations in the tibialis anterior muscle (r(2)=.3, p=.01). These results provide novel evidence that older adults exhibit greater positional variability with the ankle joint relative to young adults likely due to their inability to activate the tibialis anterior muscle from 30-60 Hz. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. 17-β-Estradiol Counteracts the Effects of High Frequency Electromagnetic Fields on Trophoblastic Connexins and Integrins

    PubMed Central

    Cervellati, Franco; Lunghi, Laura; Fabbri, Elena; Valbonesi, Paola; Marci, Roberto; Biondi, Carla; Vesce, Fortunato

    2013-01-01

    We investigated the effect of high-frequency electromagnetic fields (HF-EMFs) and 17-β-estradiol on connexins (Cxs), integrins (Ints), and estrogen receptor (ER) expression, as well as on ultrastructure of trophoblast-derived HTR-8/SVneo cells. HF-EMF, 17-β-estradiol, and their combination induced an increase of Cx40 and Cx43 mRNA expression. HF-EMF decreased Int alpha1 and β1 mRNA levels but enhanced Int alpha5 mRNA expression. All the Ints mRNA expressions were increased by 17-β-estradiol and exposure to both stimuli. ER-β mRNA was reduced by HF-EMF but augmented by 17-β-estradiol alone or with HF-EMF. ER-β immunofluorescence showed a cytoplasmic localization in sham and HF-EMF exposed cells which became nuclear after treatment with hormone or both stimuli. Electron microscopy evidenced a loss of cellular contact in exposed cells which appeared counteracted by 17-β-estradiol. We demonstrate that 17-β-estradiol modulates Cxs and Ints as well as ER-β expression induced by HF-EMF, suggesting an influence of both stimuli on trophoblast differentiation and migration. PMID:23819010

  4. Transport of 17ß-Estradiol and Testosterone in a Field Lysimeter

    USDA-ARS?s Scientific Manuscript database

    17ß-estradiol (E2) and testosterone (T) are naturally present in manures and have the potential to disrupt aquatic organisms at low concentrations. Laboratory studies have indicated that E2 and T would have limited mobility and would attenuate rapidly in soils; however, these hormones are consistent...

  5. Transport of 17beta-estradiol and testosterone in a field lysimeter

    USDA-ARS?s Scientific Manuscript database

    17ß-estradiol (E2) and testosterone (T) are present in sources such as waste treatment effluent and manures, and can potentially disrupt aquatic organisms at low concentrations. Laboratory studies consistently indicate limited mobility and rapid attenuation of E2 and T in soils; however, these hormo...

  6. Further studies of 60-Hz exposure effects on human function. Final report summary, July 3, 1989--September 15, 1993

    SciTech Connect

    Graham, C.; Cohen, H.D.

    1994-03-29

    The objective of the exploratory study was to determine whether the electric or magnetic field, presented separately in an intermittent fashion, would produce the same pattern of heart rate increases and decreases seen in the original intermittent exposure study. In addition, time of day and baseline heart rate were explored in an attempt to clarify design issues that arose from previous studies. Twenty-four healthy young men 21 to 35 years of age participated in the study. Half were exposed to a 9-kV/m electric field, and half to a 200-mG magnetic field. Within each of these groups, half were exposed in the morning and half in the afternoon.

  7. 17beta-Estradiol potentiates field excitatory postsynaptic potentials within each subfield of the hippocampus with greatest potentiation of the associational/commissural afferents of CA3.

    PubMed

    Kim, M T; Soussou, W; Gholmieh, G; Ahuja, A; Tanguay, A; Berger, T W; Brinton, R D

    2006-08-11

    We sought to determine the impact of 17beta-estradiol throughout the hippocampal trisynaptic pathway and to investigate the afferent fiber systems within CA1 and CA3 in detail. To achieve this objective, we utilized multielectrode arrays to simultaneously record the field excitatory postsynaptic potentials from the CA1, dentate gyrus, and CA3 of rat hippocampal slices in the presence or absence of 100 pM 17beta-estradiol. We confirmed our earlier findings in CA1, where 17beta-estradiol significantly increased field excitatory postsynaptic potentials amplitude (20%+/-3%) and slope (22%+/-7%). 17beta-Estradiol significantly potentiated the field excitatory postsynaptic potentials in dentate gyrus, amplitude (15%+/-4%) and slope (17%+/-5), and in CA3, amplitude (15%+/-4%) and slope (19%+/-5%). Using a high-density multielectrode array, we sought to determine the source of potentiation in CA1 and CA3 by determining the impact of 17beta-estradiol on the apical afferents and the basal afferents within CA1 and on the mossy fibers and the associational/commissural fibers within CA3. In CA1, 17beta-estradiol induced a modest increase in the amplitude (7%+/-2%) and slope (9%+/-3%) following apical stimulation with similar magnitude of increase following basal stimulation amplitude (10%+/-2%) and slope (12%+/-3%). In CA3, 17beta-estradiol augmented the mossy fiber amplitude (15%+/-3%) and slope (18%+/-6%) and the associational/commissural fiber amplitude (31%+/-13%) and slope (40%+/-15%). These results indicate that 17beta-estradiol potentiated synaptic transmission in each subfield of the hippocampal slice, with the greatest magnitude of potentiation at the associational/commissural fibers in CA3. 17beta-Estradiol regulation of CA3 responses provides a novel site of 17beta-estradiol action that corresponds to the density of estrogen receptors within the hippocampus. The implications of 17beta-estradiol potentiation of the field potential in each of the hippocampal subfields

  8. Increased voluntary drive is associated with changes in common oscillations from 13 to 60 Hz of interference but not rectified electromyography.

    PubMed

    Neto, Osmar P; Baweja, Harsimran S; Christou, Evangelos A

    2010-09-01

    The purpose of this study was to compare the capability of interference and rectified electromyography (EMG) to detect changes in the beta (13-30-HZ) and Piper (30-60-HZ) bands when voluntary force is increased. Twenty adults exerted a constant force abduction of the index finger at 15% and 50% of maximum. The common oscillations at various frequency bands (0-500 HZ) were estimated from the first dorsal interosseous muscle using cross wavelets of interference and rectified EMG. For the interference EMG signals, normalized power significantly (P < 0.01) increased with force in the beta (9.0 +/- 0.9 vs. 15.5 +/- 2.1%) and Piper (13.6 +/- 0.9 vs. 21 +/- 1.7%) bands. For rectified EMG signals, however, the beta and Piper bands remained unchanged (P > 0.4). Although rectified EMG is used in many clinical studies to identify changes in the oscillatory drive to the muscle, our findings suggest that only interference EMG can accurately capture the increase in oscillatory drive from 13 to 60 HZ with voluntary force.

  9. Very Broadband Rayleigh-Wave Dispersion (0.06 - 60 Hz) and Shear-Wave Velocity Structure Under Yucca Flat, Nevada Test Site

    NASA Astrophysics Data System (ADS)

    Schramm, K. A.; Bilek, S. L.; Patton, H. J.; Abbott, R. E.; Stead, R.; Pancha, A.; White, R.

    2009-12-01

    Earth structure plays an important role in the generation of seismic waves for all sources. Nowhere is this more evident than at near-surface depths where man-made sources, such as explosions, are conducted. For example, short-period Rayleigh waves (Rg) are excited and propagate in the upper 2 km of Earth's crust. The importance of Rg in the generation of S waves from explosion sources through near-source scattering depends greatly on the shear-wave velocity structure at very shallow depths. Using three distinct datasets, we present a very broadband Rayleigh-wave phase velocity dispersion curve for the Yucca Flat (YF) region of the Nevada Test Site (NTS). The first dataset consists of waveforms of historic NTS explosions recorded on regional seismic networks and will provide information for the lowest frequencies (0.06-0.3 Hz). The second dataset is comprised of waveforms from a non-nuclear explosion on YF recorded at near-local distances and will be used for mid-range frequencies (0.2-1.5 Hz). The third dataset contains high-frequency waveforms recorded from refraction microtremor surveys on YF. This dataset provides information between 1.5 and 60 Hz. Initial results from the high frequency dataset indicate velocities range from 0.45-0.9 km/s at 1.5 Hz and 0.25-0.45 km/s at 60 Hz. The broadband nature of the dispersion curve will allow us to invert for the shear-wave velocity structure to 10 km depth, with focus on shallow depths where nuclear tests were conducted in the YF region. The velocity model will be used by researchers as a tool to aid the development of new explosion source models that incorporate shear wave generation. The new model can also be used to help improve regional distance yield estimation and source discrimination for small events.

  10. [Interhemispheric relations of the EEG power of cortical potentials in the band of 1-60 Hz during formation and testing of cognitive set to facial expression].

    PubMed

    Dumenko, V N; Kozlov, M K; Kurova, N S; Cheremushkin, E A

    2009-01-01

    Interhemispheric relations of the EEG power in the 1-60 frequency band were studied at the stages of formation and testing of the cognitive set to facial expression. Different topographic asymmetry patterns were revealed in subjects with different set plasticity. In subjects without behavioral actualization (n = 11) of the set at the stage of set formation, EEG power in the gamma band (21-40 and 41-60 Hz) prevailed in the frontal areas of the right hemisphere, whereas the power of electrical oscillations in the bands of 2-7 and 8-13 Hz was higher also in the frontal areas but of the left hemisphere. At the stage of set testing, this basic topographical asymmetry pattern persisted. Formation of the set in subjects with pronounced actualization (n = 18) was characterized by another topographical asymmetry pattern: a significant excess of the power of gamma oscillations was observed in the posterotemporal and occipital areas of the left hemisphere, whereas the power of oscillations in the bands 2-7, 8-13, and 14-20 Hz was higher also in the posterior areas but of the right hemisphere. No asymmetry in the EEG power was observed in these subjects at the stage of set testing.

  11. c-Fos induction by a 14T magnetic field in visceral and vestibular relays of the female rat brainstem is modulated by estradiol

    PubMed Central

    Cason, Angie M.; Kwon, Bumsup; Smith, James C.; Houpt, Thomas A.

    2010-01-01

    There is increasing evidence that high magnetic fields interact with the vestibular system of humans and rodents. In rats, exposure to high magnetic fields of 7T or above induces locomotor circling and leads to a conditioned taste aversion if paired with a novel taste. Sex differences in the behavioral responses to magnetic field exposure have been found, such that female rats show more locomotor circling and enhanced conditioned taste aversion compared to male rats. To determine if estrogen modulates the neural response to high magnetic fields, c-Fos expression after 14T magnetic field exposure was compared in ovariectomized rats and ovariectomized rats with estradiol replacement. Compared to sham exposure, magnetic field exposure induced significantly more c-Fos positive cells in the nucleus of the solitary tract and the parabrachial, medial vestibular, prepositus, and supragenualis nuclei. Furthermore, there was a significant asymmetry in c-Fos induction between sides of the brainstem in several regions. In ovariectomized rats, there was more c-Fos expressed in the right side compared to left side in the locus coeruleus and parabrachial, superior vestibular, and supragenualis nuclei; less expression in the right compared to left side of the medial vestibular; and no asymmetry in the prepositus nucleus and the nucleus of the solitary tract. Chronic estradiol treatment modulated the neural response in some regions: less c-Fos was induced in the superior vestibular nucleus and locus coeruleus after estradiol replacement; estradiol treatment eliminated the asymmetry of c-Fos expression in the locus coeruleus and supragenualis nucleus, created an asymmetry in the prepositus nucleus and reversed the asymmetry in the parabrachial nucleus. These results suggest that ovarian steroids may mediate sex differences in the behavioral responses to magnetic field exposure at the level of visceral and vestibular nuclei of the brainstem. PMID:20553875

  12. A simple dye-sensitized solar cell sealing technique using a CO 2 laser beam excited by 60 Hz AC discharges

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Gil; Hong, Ji-Tae; Xu, Guo-Cheng; Kim, Ho-Sung; Lee, Kyoung-Jun; Park, Sung-Joon; Kim, Whi-Young; Kim, Hee-Je

    2010-09-01

    Dye-sensitized solar cells (DSSCs) use two glass substrates (photo electrode and counter electrode) coated with fluorine-doped tin oxide (FTO) to harvest light into the cell and to collect electrons. The space between the photo electrode and the counter electrode are filled with a liquid type electrolyte for electron transfer into the cell. Therefore, an appropriate sealing method is required to prevent the liquid electrolyte leaking out. In this paper, a simple CO 2 laser beam with TEM 00 mode excited by a 60 Hz AC discharge was used to seal two glass substrates coated with FTO for the fabrication of DSSCs. The sealing technique improved the durability and stability of the DSSCs. The optimal conditions for the sealing of the DSSCs are related to the pin-hole diameter, the discharge current and the moving velocity of the target. Especially, the CO 2 laser beam is used as a heat source that is precisely controlled by the pin-hole, which plays an important role in adjusting its spot size. From these results, the maximum laser power was found to be 40 W at 18 Torr and 35 mA. In order to achieve the best sealing quality, the following parameters are required: a pin-hole diameter of 4 mm, input voltage of 10.73 kV, discharge current of 9.31 mA, moving velocity of 1 mm/s and distance from the target surface of 26.5 cm. Scanning electron microscope images show that the sealing quality obtained using the CO 2 laser beam is superior to that obtained using a hot press or soldering iron.

  13. Blood Test: Estradiol

    MedlinePlus

    ... 2-Year-Old Blood Test: Estradiol KidsHealth ... measures the level of the hormone estradiol in the bloodstream. Estradiol plays an important role in sexual development: It's the most important form of the hormone ...

  14. Estradiol Transdermal Patch

    MedlinePlus

    Most brands of estradiol transdermal patches are used to treat hot flushes (hot flashes; sudden strong feelings of heat ... different medication that does not contain estrogen. Most brands of estradiol transdermal patches are also sometimes used ...

  15. [Polish regulations on maximum admissible intensities for electric and magnetic frequencies of 60 Hz and the European Union recommendations for electrical power engineering].

    PubMed

    Groszko, Marian

    2003-01-01

    Electric and magnetic fields of 50 Hz from electric power devices affect not only workers, but also the general population, as these devices are also located in populated areas, hence the duality of regulations on maximum admissible intensities. This paper presents these regulations and discusses in detail the changes of 2001. Based on the Polish regulations, hygienic evaluation of electric power devices has been attempted. The Polish regulations on the 50 Hz electromagnetic fields were compared with relevant international regulations of CENELEC and the European Union recommendations. Our maximum admissible intensities have been found to conform with the international standards.

  16. Blood Test: Estradiol

    MedlinePlus

    ... work so closely with one another, doctors often perform the estradiol test with tests for LH, FSH, testosterone (the male sex hormone — but teen and adult females produce some, too), and progesterone ( ...

  17. Drospirenone/ethinyl estradiol.

    PubMed

    Rapkin, Andrea J; Sorger, Shelley N; Winer, Sharon A

    2008-02-01

    Drospirenone 3 mg/ethinyl estradiol 20 microg (24/4) is a new unique oral contraceptive formulation that combines in a novel dosing regimen the lowest dosage of ethinyl estradiol commonly used today with drospirenone, an innovative progestin. Drospirenone is a compound closely resembling progesterone, but with the antimineralocorticoid and antiandrogenic properties of a related therapeutic agent, the diuretic, antihypertensive and androgen receptor antagonist, 17alpha-spironolactone. The prolongation of hormonally active pills in the monthly drospirenone/ethinyl estradiol cycle from 21 days to 24 days, followed by 4 days of inactive pills, is an interesting variant of the recently developed extended pill regimens (1). Recent contraceptive research has focused on improving side effect profiles and providing noncontraceptive health and lifestyle advantages. Many of these benefits are now supported with evidence-based medicine (2). Most available oral contraceptives improve cycle regularity, menstrual pain, excessive menstrual flow and acne. However, weight gain, bloating, food cravings, breast tenderness and mood alterations (especially irritability and depression and the complex of affective, behavioral and somatic symptoms of premenstrual syndrome [PMS] and the severe form of PMS, premenstrual dysphoric disorder [PMDD]) are not generally improved with the traditional oral contraceptive formulations (3). Drospirenone/ethinyl estradiol 24/4 is currently the only hormonally based contraceptive regimen with large, randomized, controlled trials demonstrating efficacy for PMDD. It has received U.S. Food and Drug Administration (FDA) indications not only for the prevention of pregnancy but also for PMDD and for moderate acne vulgaris in women who choose oral contraception for birth control (4, 5). Copyright 2008 Prous Science, S.A.U. or its licensors. All rights reserved.

  18. Estradiol and the Developing Brain

    PubMed Central

    McCarthy, Margaret M.

    2009-01-01

    Estradiol is the most potent and ubiquitous member of a class of steroid hormones called estrogens. Fetuses and newborns are exposed to estradiol derived from their mother, their own gonads, and synthesized locally in their brains. Receptors for estradiol are nuclear transcription factors that regulate gene expression but also have actions at the membrane, including activation of signal transduction pathways. The developing brain expresses high levels of receptors for estradiol. The actions of estradiol on developing brain are generally permanent and range from establishment of sex differences to pervasive trophic and neuroprotective effects. Cellular end points mediated by estradiol include the following: 1) apoptosis, with estradiol preventing it in some regions but promoting it in others; 2) synaptogenesis, again estradiol promotes in some regions and inhibits in others; and 3) morphometry of neurons and astrocytes. Estradiol also impacts cellular physiology by modulating calcium handling, immediate-early-gene expression, and kinase activity. The specific mechanisms of estradiol action permanently impacting the brain are regionally specific and often involve neuronal/glial cross-talk. The introduction of endocrine disrupting compounds into the environment that mimic or alter the actions of estradiol has generated considerable concern, and the developing brain is a particularly sensitive target. Prostaglandins, glutamate, GABA, granulin, and focal adhesion kinase are among the signaling molecules co-opted by estradiol to differentiate male from female brains, but much remains to be learned. Only by understanding completely the mechanisms and impact of estradiol action on the developing brain can we also understand when these processes go awry. PMID:18195084

  19. Effects of repeated 9 and 30-day exposure to extremely low-frequency electromagnetic fields on social recognition behavior and estrogen receptors expression in olfactory bulb of Wistar female rats.

    PubMed

    Bernal-Mondragón, C; Arriaga-Avila, V; Martínez-Abundis, E; Barrera-Mera, B; Mercado-Gómez, O; Guevara-Guzmán, R

    2017-02-01

    We investigated the short- and long-term effects of extremely low-frequency electromagnetic fields (EMF) on social recognition behavior and expression of α- and β-estrogen receptors (ER). Rats were exposed to 60-Hz electromagnetic fields for 9 or 30 days and tested for social recognition behavior. Immunohistochemistry and western blot assays were performed to evaluate α- and β-ER expression in the olfactory bulb of intact, ovariectomized (OVX), and ovariectomized+estradiol (E2) replacement (OVX+E2). Ovariectomization showed impairment of social recognition after 9 days of EMF exposure and a complete recovery after E2 replacement and so did those after 30 days. Short EMF exposure increased expression of β-ER in intact, but not in the others. Longer exposure produced a decrease in intact but an increase in OVX and OVX+E2. Our findings suggest a significant role for β-estrogen receptors and a lack of effect for α-estrogen receptors on a social recognition task. EMF: extremely low frequency electromagnetic fields; ERs: estrogen receptors; OB: olfactory bulb; OVX: ovariectomized; OVX + E2: ovariectomized + estradiol replacement; IEI: interexposure interval; β-ER: beta estrogen receptor; E2: replacement of estradiol; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; WB: Western blot; PBS: phosphate-buffer saline; PB: phosphate-buffer.

  20. Estradiol and neurodegenerative oxidative stress.

    PubMed

    Nilsen, Jon

    2008-10-01

    Estradiol is a potent preventative against neurodegenerative disease, in part, by activating antioxidant defense systems scavenging reactive oxygen species, limiting mitochondrial protein damage, improving electron transport chain activity and reducing mitochondrial DNA damage. Estradiol also increases the activity of complex IV of the electron transport chain, improving mitochondrial respiration and ATP production under normal and stressful conditions. However, the high oxidative cellular environment present during neurodegeneration makes estradiol a poor agent for treatment of existing disease. Oxidative stress stimulates the production of the hydroperoxide-dependent hydroxylation of estradiol to the catecholestrogen metabolites, which can undergo reactive oxygen species producing redox cycling, setting up a self-generating toxic cascade offsetting any antioxidant/antiapoptotic effects generated by the parent estradiol. Additional disease-induced factors can further perpetuate this cycle. For example dysregulation of the catecholamine system could alter catechol-O-methyltransferase-catalyzed methylation, preventing removal of redox cycling catecholestrogens from the system enhancing pro-oxidant effects of estradiol.

  1. delta 9-THC and 17-beta-estradiol in hippocampus.

    PubMed

    Foy, M R; Teyler, T J; Vardaris, R M

    1982-04-01

    Electrophysiological field potentials recorded from in vitro hippocampal slice preparations show dose-dependent differences in response to 17-beta-estradiol (E2) and delta-9-tetrahydrocannabinol (THC) added to the incubation medium. Using a wide range of doses (1 pM-10 nM), it was found that mid-range concentrations of estradiol (100 pM) and THC (10 pM) tended to increase field potentials in CA1 of rodents. Higher dose levels of each agent were found to depress neuronal activity. In the context of prior findings, these results suggest that the two compounds share a common mechanism of action in the hippocampus.

  2. 77 FR 31722 - New Animal Drugs; Change of Sponsor; Estradiol; Estradiol Benzoate and Testosterone Propionate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-30

    ...). ENCORE (COMPUDOSE 400) 522.840 (estradiol benzoate). 135-906 COMPONENT E-H 522.842 (estradiol benzoate... COMPONENT E-C 522.1940 (progesterone and estradiol benzoate) with TYLAN (tylosin tartrate). COMPONENT E-S... estradiol) with TYLAN (tylosin tartrate). 200-224 COMPONENT T-H 522.2476 (trenbolone acetate) with TYLAN...

  3. Effects of 17 b-estradiol and extremely low-frequency electromagnetic fields on social recognition memory in female rats: a possible interaction?

    PubMed

    Reyes-Guerrero, Gloria; Vázquez-García, Mario; Elias-Viñas, David; Donatti-Albarrán, Olga A; Guevara-Guzmán, Rosalinda

    2006-06-20

    We have investigated a potential memory-enhancing effect of exposure to extremely low-frequency electromagnetic fields (ELF EMF) in female rats and its dependence on estrogen, using a social recognition task. A juvenile social recognition paradigm was used and memory retention tested at 30 and 300 min after an adult was exposed to a juvenile during two 4-min trials. Results showed that an intact social recognition memory was present at 30 min in both gonadally intact and ovariectomized rats with, or without, ELF-EMF. However, whereas gonadally intact control females failed to show retention of the recognition memory at 300 min, those additionally exposed to ELF EMF did. This shows that the enhanced duration effect of ELF EMF on social recognition memory occurs in gonadally intact females as well as in males. In addition, results showed that the ELF EMF facilitation of memory retention was prevented by ovariectomy but restored by exogenous treatment with estrogen. This suggests that this ELF EMF effect on social recognition memory is estrogen-dependent.

  4. [Oral combined contraception: is there any difference between ethinyl-estradiol and estradiol?].

    PubMed

    Trémollieres, F

    2012-02-01

    Estradiol 17-β, which is the natural estrogen in women, offers an alternative to ethinyl-estradiol to be used in combined oral contraceptives. Thanks to its biochemical structure, estradiol has a far lesser impact on the synthesis of hepatic proteins than ethinyl-estradiol, which is likely to result in a better metabolic and vascular profile. However and until lately, the different clinical trials that had investigated estradiol-containing oral contraceptives were limited by bleeding disturbances, with breakthrough and irregular bleeding and higher rates of discontinuation. Development of anti-gonadotropic progestins with a potent endometrial activity is likely to make possible their combination with estradiol in oral contraceptives. The objective of this current review is to provide an overview of the development of combined oral contraceptives containing natural estrogen from the respective biochemical and pharmacological characteristics of ethinyl-estradiol and estradiol.

  5. Effect of ambient levels of power-line-frequency electric fields on a developing vertebrate

    SciTech Connect

    Blackman, C.F.; House, D.E.; Benane, S.G.; Joines, W.T.; Spiegel, R.J.

    1988-01-01

    Fertilized eggs of Gallus domesticus were exposed continuously during their 21-day incubation period to either 50- or 60-Hz sinusoidal electric fields at an average intensity of 10 Vrms/m. The exposure apparatus was housed in an environmental room maintained at 37 degrees C and 55-60% relative humidity (RH). Within 1.5 days after hatching, the chickens were removed from the apparatus and tested. The test consisted of examining the effect of 50- or 60-Hz electromagnetic fields at 15.9 Vrms/m and 73 nTrms (in a local geomagnetic field of 38 microT, 85 degrees N) on efflux of calcium ions from the chicken brain. For eggs exposed to 60-Hz electric fields during incubation, the chicken brains demonstrated a significant response to 50-Hz fields but not to 60-Hz fields, in agreement with the results from commercially incubated eggs. In contrast, the brains from chicks exposed during incubation to 50-Hz fields were not affected by either 50- or 60-Hz fields. These results demonstrate that exposure of a developing organism to ambient power-line-frequency electric fields at levels typically found inside buildings can alter the response of brain tissue to field-induced calcium-ion efflux. The physiological significance of this finding has yet to be established.

  6. Environmental magnetic fields: Influences on early embryogenesis

    SciTech Connect

    Cameron, I.L.; Hardman, W.E.; Winters, W.D.; Zimmerman, S.; Zimmerman, A.M. )

    1993-04-01

    A 10-mG, 50 to 60-Hz magnetic field is in the intensity and frequency range that people worldwide are often exposed to in homes and in the workplace. Studies about the effects of 50- to 100-Hz electromagnetic fields on various species of animal embryos (fish, chick, fly, sea urchin, rat, and mouse) indicate that early stages of embryonic development are responsive to fluctuating magnetic fields. Chick, sea urchin, and mouse embryos are responsive to magnetic field intensities of 10-100 mG. Results from studies on sea urchin embryos indicate that exposure to conditions of rotating 60-Hz magnetic fields, e.g., similar to those in our environment, interferes with cell proliferation at the morula stage in a manner dependent on field intensity. The cleavage stages, prior to the 64-cell stage, were not delayed by this rotating 60-Hz magnetic field suggesting that the ionic surges, DNA replication, and translational events essential for early cleavage stages were not significantly altered. Studies of histone synthesis in early sea urchin embryos indicated that the rotating 60-Hz magnetic field decreased zygotic expression of early histone genes at the morula stage and suggests that this decrease in early histone production was limiting to cell proliferation. Whether these comparative observations from animal development studies will be paralleled by results from studies of human embryogenesis, as suggested by some epidemiology studies, has yet to be established. 38 refs.

  7. 21 CFR 522.840 - Estradiol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Estradiol. 522.840 Section 522.840 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.840 Estradiol....

  8. 21 CFR 522.840 - Estradiol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Estradiol. 522.840 Section 522.840 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.840 Estradiol....

  9. 21 CFR 522.840 - Estradiol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Estradiol. 522.840 Section 522.840 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.840 Estradiol....

  10. 21 CFR 522.840 - Estradiol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Estradiol. 522.840 Section 522.840 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.840 Estradiol....

  11. 21 CFR 522.840 - Estradiol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Estradiol. 522.840 Section 522.840 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.840 Estradiol....

  12. Effect of ambient levels of power-line-frequency electric fields on a developing vertebrate (journal version)

    SciTech Connect

    Blackman, C.F.; House, D.E.; Benane, S.G.; Joines, W.T.; Spiegel, R.J.

    1988-01-01

    Fertilized eggs of Gallus domesticus were exposed continuously during their 21-day incubation period to either 50 or 60-Hz sinusoidal electric fields at an average intensity of 10 Vrms/m. Within 1.5 days after hatching, the chickens were removed from the apparatus and tested. The test consisted of examining the effect of 50- or 60-Hz electromagnetic fields at 15.9 Vrms/m and 73 nTrms (in a local geomagnetic field of 38 uT, 85 deg N) on efflux of calcium ions from the chicken brain. For eggs exposed to 60-Hz electric fields during incubation, the chicken brains demonstrated a significant response to 50-Hz fields but not to 60-Hz fields, in agreement with the results from commercially incubated eggs. In contrast, the brains from chicks exposed during incubation to 50-Hz fields were not affected by either 50- or 60-Hz fields. These results demonstrate that exposure of a developing organism to ambient power-line-frequency electric fields at levels typically found inside buildings can alter the response of brain tissue to radiation-induced calcium-ion efflux.

  13. 21 CFR 556.240 - Estradiol and related esters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Estradiol and related esters. 556.240 Section 556... Tolerances for Residues of New Animal Drugs § 556.240 Estradiol and related esters. No residues of estradiol, resulting from the use of estradiol or any of the related esters, are permitted in excess of the following...

  14. 21 CFR 556.240 - Estradiol and related esters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Estradiol and related esters. 556.240 Section 556... Tolerances for Residues of New Animal Drugs § 556.240 Estradiol and related esters. No residues of estradiol, resulting from the use of estradiol or any of the related esters, are permitted in excess of the...

  15. 21 CFR 556.240 - Estradiol and related esters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Estradiol and related esters. 556.240 Section 556... Tolerances for Residues of New Animal Drugs § 556.240 Estradiol and related esters. No residues of estradiol, resulting from the use of estradiol or any of the related esters, are permitted in excess of the...

  16. Ethinyl Estradiol and Etonogestrel Vaginal Ring

    MedlinePlus

    ... a class of medications called combination hormonal contraceptives (birth control medications). Etonogestrel is a progestin and ethinyl estradiol ... contraceptive ring is a very effective method of birth control but does not prevent the spread of human ...

  17. Estradiol: a rhythmic, inhibitory, indirect control of meal size.

    PubMed

    Eckel, Lisa A

    2004-08-01

    The classic analyses of the inhibitory effects of cholecystokinin (CCK) on meal size, conducted by Professor Gerard P. Smith and his colleagues at the Bourne Laboratory, inspired my initial interest in this field. My current research, which investigates the role of estradiol in the control of meal size, continues to be guided by Gerry's thoughtful, scientific approach to the study of ingestive behavior. In 1996, the year I arrived as a Postdoctoral Fellow at the Bourne Laboratory, Gerry published a new theory of the controls of meal size. In this important paper, Gerry proposed that the controls of meal size can be either direct or indirect. He argued that direct controls of meal size interact with peripheral, preabsorptive receptors that are sensitive to the chemical, mechanical, and colligative properties of ingested food and that indirect controls of meal size function to modulate the activity of direct controls. The purpose of this review is to illustrate how Gerry's theory has guided much of what is known about the mechanism by which estradiol inhibits food intake in female rats. I will provide evidence, primarily from behavioral studies of gonadally intact and ovariectomized rats, that estradiol exerts phasic and tonic inhibitory effects on food intake by acting as a rhythmic, inhibitory, indirect control of meal size.

  18. Analysis of magnetic field levels at KSC

    NASA Technical Reports Server (NTRS)

    Christodoulou, Christos G.

    1994-01-01

    The scope of this work is to evaluate the magnetic field levels of distribution systems and other equipment at Kennedy Space Center (KSC). Magnetic fields levels in several operational areas and various facilities are investigated. Three dimensional mappings and contour are provided along with the measured data. Furthermore, the portion of magnetic fields generated by the 60 Hz fundamental frequency and the portion generated by harmonics are examined. Finally, possible mitigation techniques for attenuating fields from electric panels are discussed.

  19. Calcium signaling in lymphocytes and ELF fields. Evidence for an electric field metric and a site of interaction involving the calcium ion channel.

    PubMed

    Liburdy, R P

    1992-04-13

    Calcium influx increased during mitogen-activated signal transduction in thymic lymphocytes exposed to a 22 mT, 60 Hz magnetic field (E induced = 1.7 mV/cm, 37 degrees C, 60 min). To distinguish between an electric or a magnetic field dependence a special multi-ring annular cell culture plate based on Faraday's Law of Induction was employed. Studies show a dependence on the strength of the induced electric field at constant magnetic flux density. Moreover, exposure to a pure 60 Hz electric field or to a magnetically-induced electric field of identical strength resulted in similar changes in calcium transport. The first real-time monitoring of [Ca2+]i during application of a 60 Hz electric field revealed an increase in [Ca2+]i observed 100 s after mitogen stimulation; this suggests that the plateau phase rather than the early phase of calcium signaling was influenced. The hypothesis was tested by separating, in time, the early release of calcium from intracellular stores from the influx of extracellular calcium. In calcium-free buffer, 60 Hz field exerted little influence on the early release of calcium from intracellular stores. In contrast, addition of extracellular calcium during exposure enhanced calcium influx through the plasma membrane. Alteration of the plateau phase of calcium signaling implicates the calcium channel as a site of field interaction. In addition, an electric field exposure metric is mechanistically consistent with a cell-surface interaction site.

  20. Cognitive effects of estradiol after menopause

    PubMed Central

    St. John, Jan A.; Hodis, Howard N.; McCleary, Carol A.; Stanczyk, Frank Z.; Shoupe, Donna; Kono, Naoko; Dustin, Laurie; Allayee, Hooman; Mack, Wendy J.

    2016-01-01

    Objective: To test the hypothesis that effects of estrogen-containing hormone therapy on cognitive abilities differ between postmenopausal women near to, and further from, menopause. Methods: In this randomized, double-blind, placebo-controlled trial, healthy women within 6 years of menopause or 10+ years after menopause were randomly assigned to oral 17β-estradiol 1 mg/d or placebo. Women with a uterus received cyclic micronized progesterone vaginal gel or placebo. The primary outcome assessed at 2.5 and 5 years, compared between treatment groups, was change in a standardized composite of neuropsychological test scores assessing verbal episodic memory. Secondary outcomes assessed executive functions and global cognition. Results: A total of 567 women were included in modified intention-to-treat analyses after a mean treatment duration of 57 months. For verbal memory, the mean estradiol minus placebo standardized difference in composite scores (−0.06, 95% confidence interval −0.22 to 0.09) was not significant (2-tailed p = 0.33). Differences were similar in early and late postmenopause groups (2-tailed interaction p = 0.88). Interactions between postmenopause groups and differences between treatment groups were not significant for executive functions or global cognition. Conclusions: Estradiol initiated within 6 years of menopause does not affect verbal memory, executive functions, or global cognition differently than therapy begun 10+ years after menopause. Estradiol neither benefits nor harms these cognitive abilities regardless of time since menopause. Classification of evidence: This study provides Class I evidence that estradiol initiated within 6 years of menopause does not affect cognition at 2.5 years differently than estradiol initiated 10+ years after menopause. PMID:27421538

  1. Copper and endogenous mediators of estradiol action.

    PubMed

    Fishman, J H; Fishman, J

    1988-04-29

    Divalent copper increases by severalfold specific estradiol binding in rat uterine cytosol at 37 degrees C. Two endogenous substances have now been isolated from the cytosol one of which sharply inhibits the copper effect while the other sharply promotes it. The inhibitor is thermostable, it is adsorbed by dextran coated charcoal and elutes from Sephadex columns with water. The promoter is thermolabile at 60 degrees C, it is not readily adsorbed by the charcoal and elutes from Sephadex columns with KCl. The two substances are thought to be mediators of estradiol action.

  2. Estradiol and raloxifene modulate hippocampal gamma oscillations during a spatial memory task.

    PubMed

    Schroeder, Anna; Hudson, Matthew; Du, Xin; Wu, Yee Wen Candace; Nakamura, Jay; van den Buuse, Maarten; Jones, Nigel C; Hill, Rachel A

    2017-04-01

    Previous work suggests that estradiol regulates the expression of hippocampal parvalbumin as well as hippocampus-dependent spatial memory in mice. Parvalbumin interneurons generate neuronal oscillatory activity in the gamma frequency range (30-80Hz) and gamma oscillations are closely linked with higher cognitive functions. Raloxifene, a selective estrogen receptor modulator, shows beneficial effects on human cognitive performance, and has few peripheral side effects unlike estradiol, but the biological mechanisms which underpin these benefits are not clear. This study aimed to investigate whether estradiol and raloxifene modulate hippocampal gamma-band oscillations during spatial memory performance. Prepubescent female mice were ovariectomized (OVX) and implanted with a subcutaneous pellet of either estradiol (E2), raloxifene or placebo. During adulthood, local field potentials were recorded from the dorsal hippocampus while mice were performing the Y-maze hippocampus-dependent spatial memory task. Ovariectomy caused deficits in spatial memory, accompanied by a significant reduction in hippocampal gamma oscillations, specifically during decision making. Estradiol as well as raloxifene rescued both behavioural and electrophysiological deficits. These data have significant implications for disorders of cognitive impairment where altered gamma oscillations are apparent, such as schizophrenia.

  3. 21 CFR 556.240 - Estradiol and related esters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.240 Estradiol and related esters. No residues of estradiol... increments above the concentrations of estradiol naturally present in untreated animals: (a) In uncooked...

  4. 21 CFR 522.842 - Estradiol benzoate and testosterone propionate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Estradiol benzoate and testosterone propionate... ANIMAL DRUGS § 522.842 Estradiol benzoate and testosterone propionate. (a) Sponsors. See sponsors in... testosterone propionate (one implant consisting of 8 pellets, each pellet containing 2.5 mg estradiol...

  5. 21 CFR 522.842 - Estradiol benzoate and testosterone propionate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Estradiol benzoate and testosterone propionate... ANIMAL DRUGS § 522.842 Estradiol benzoate and testosterone propionate. (a) Sponsors. See sponsors in... testosterone propionate (one implant consisting of 8 pellets, each pellet containing 2.5 mg estradiol...

  6. 21 CFR 522.842 - Estradiol benzoate and testosterone propionate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Estradiol benzoate and testosterone propionate... ANIMAL DRUGS § 522.842 Estradiol benzoate and testosterone propionate. (a) Sponsors. See sponsors in... testosterone propionate (one implant consisting of 8 pellets, each pellet containing 2.5 mg estradiol...

  7. 21 CFR 522.842 - Estradiol benzoate and testosterone propionate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Estradiol benzoate and testosterone propionate... ANIMAL DRUGS § 522.842 Estradiol benzoate and testosterone propionate. (a) Sponsors. See sponsors in... testosterone propionate (one implant consisting of 8 pellets, each pellet containing 2.5 mg estradiol...

  8. 21 CFR 522.842 - Estradiol benzoate and testosterone propionate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Estradiol benzoate and testosterone propionate... ANIMAL DRUGS § 522.842 Estradiol benzoate and testosterone propionate. (a) Sponsors. See sponsors in... testosterone propionate (one implant consisting of 8 pellets, each pellet containing 2.5 mg estradiol...

  9. Inhibition of Estradiol Synthesis Impairs Fear Extinction in Male Rats

    ERIC Educational Resources Information Center

    Graham, Bronwyn M.; Milad, Mohammed R.

    2014-01-01

    Emerging research has demonstrated that the sex hormone estradiol regulates fear extinction in female rodents and women. Estradiol may also regulate fear extinction in males, given its role in synaptic plasticity in both sexes. Here we report that inhibition of estradiol synthesis during extinction training, via the aromatase inhibitor fadrozole,…

  10. Inhibition of Estradiol Synthesis Impairs Fear Extinction in Male Rats

    ERIC Educational Resources Information Center

    Graham, Bronwyn M.; Milad, Mohammed R.

    2014-01-01

    Emerging research has demonstrated that the sex hormone estradiol regulates fear extinction in female rodents and women. Estradiol may also regulate fear extinction in males, given its role in synaptic plasticity in both sexes. Here we report that inhibition of estradiol synthesis during extinction training, via the aromatase inhibitor fadrozole,…

  11. 21 CFR 522.2477 - Trenbolone acetate and estradiol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... milligrams (mg) trenbolone acetate and 24 mg estradiol (one implant consisting of 6 pellets, each pellet containing 20 mg trenbolone acetate and 4 mg estradiol) per implant dose. (B) 120 mg trenbolone acetate and 24 mg estradiol (one implant consisting of 7 pellets, each of 6 pellets containing 20 mg...

  12. 21 CFR 522.1940 - Progesterone and estradiol benzoate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...: (1) Suckling beef calves—(i) Amount—(A) 100 milligrams (mg) progesterone and 10 mg estradiol benzoate (one implant consisting of 4 pellets, each pellet containing 25 mg progesterone and 2.5 mg estradiol benzoate) per implant dose. (B) 100 mg progesterone and 10 mg estradiol benzoate (one implant consisting...

  13. 21 CFR 522.2477 - Trenbolone acetate and estradiol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... milligrams (mg) trenbolone acetate and 24 mg estradiol (one implant consisting of 6 pellets, each pellet containing 20 mg trenbolone acetate and 4 mg estradiol) per implant dose. (B) 120 mg trenbolone acetate and 24 mg estradiol (one implant consisting of 7 pellets, each of 6 pellets containing 20 mg...

  14. EFFECTS OF 17B ESTRADIOL AND ETHINYL ESTRADIOL ON REPRODUCTIVE INDICATORS IN LABORATORY-EXPOSED CUNNER, TAUTOGOLABRUS ADPERSUS

    EPA Science Inventory

    Cunner (Tautogolabrus adspersus) are being studied in our laboratory to evaluate how 17 - estradiol and ethinyl estradiol affect their reproductive success. Cunner was selected because this species spawns daily, is common in estuarine areas, is easily obtainable, and is amenable ...

  15. EFFECTS OF 17B ESTRADIOL AND ETHINYL ESTRADIOL ON REPRODUCTIVE INDICATORS IN LABORATORY-EXPOSED CUNNER, TAUTOGOLABRUS ADPERSUS

    EPA Science Inventory

    Cunner (Tautogolabrus adspersus) are being studied in our laboratory to evaluate how 17 - estradiol and ethinyl estradiol affect their reproductive success. Cunner was selected because this species spawns daily, is common in estuarine areas, is easily obtainable, and is amenable ...

  16. THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN

    EPA Science Inventory

    THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN.
    Harland and Liburdy (1) reported that 1.2-uT, 60-Hz magnetic fields could significantly block the inhibitory action of pharmacological levels of tamoxifen (10-7 M) on the growth of MCF-7 human br...

  17. THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN

    EPA Science Inventory

    THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN.
    Harland and Liburdy (1) reported that 1.2-uT, 60-Hz magnetic fields could significantly block the inhibitory action of pharmacological levels of tamoxifen (10-7 M) on the growth of MCF-7 human br...

  18. Sorption and degradation of 17ß-estradiol-17sulfate in agricultural soils

    USDA-ARS?s Scientific Manuscript database

    17ß-estradiol (E2) can induce endocrine disruptions at low concentrations. Laboratory studies have indicated low potential for persistence and mobility of E2 in the environment, and yet field studies measure estrogens at concentrations of concern. Humans and animals eliminate E2 primarily as a conju...

  19. Modeling sorption and degradation of 17B-estradiol-17-sulfate in agricultural soils

    USDA-ARS?s Scientific Manuscript database

    The natural steroid hormone, 17B-estradiol (E2), can be an endocrine disruptor at part-per trillion levels. Laboratory studies indicate a low potential for E2 persistence and mobility in the environment; however, field studies consistently indicate the presence of E2 and its primary metabolite, estr...

  20. ELEVATION OF SERUM 17-B-ESTRADIOL IN CHANNEL CATFISH FOLLOWING INJECTION OF 17-B-ESTRADIOL, ETHYNYL ESTRADIOL, ESTRONE, ESTRIOL, AND ESTRADIOL-17B- GLUCURONIDE

    EPA Science Inventory

    17-b-Estradiol is naturally converted in numerous organisms to various derivatives/metabolites, which may be excreted from the organism into its immediate external environment. There is a paucity of data regarding the biological effects of the derivatives/metabolites on aquatic o...

  1. Circulating Estradiol Regulates Brain-Derived Estradiol via Actions at GnRH Receptors to Impact Memory in Ovariectomized Rats

    PubMed Central

    Black, Katelyn L.; Daniel, Jill M.

    2016-01-01

    Abstract Systemic estradiol treatment enhances hippocampus-dependent memory in ovariectomized rats. Although these enhancements are traditionally thought to be due to circulating estradiol, recent data suggest these changes are brought on by hippocampus-derived estradiol, the synthesis of which depends on gonadotropin-releasing hormone (GnRH) activity. The goal of the current work is to test the hypothesis that peripheral estradiol affects hippocampus-dependent memory through brain-derived estradiol regulated via hippocampal GnRH receptor activity. In the first experiment, intracerebroventricular infusion of letrozole, which prevents the synthesis of estradiol, blocked the ability of peripheral estradiol administration in ovariectomized rats to enhance hippocampus-dependent memory in a radial-maze task. In the second experiment, hippocampal infusion of antide, a long-lasting GnRH receptor antagonist, blocked the ability of peripheral estradiol administration in ovariectomized rats to enhance hippocampus-dependent memory. In the third experiment, hippocampal infusion of GnRH enhanced hippocampus-dependent memory, the effects of which were blocked by letrozole infusion. Results indicate that peripheral estradiol-induced enhancement of cognition is mediated by brain-derived estradiol via hippocampal GnRH receptor activity. PMID:28032117

  2. AC photovoltaic module magnetic fields

    SciTech Connect

    Jennings, C.; Chang, G.J.; Reyes, A.B.; Whitaker, C.M.

    1997-12-31

    Implementation of alternating current (AC) photovoltaic (PV) modules, particularly for distributed applications such as PV rooftops and facades, may be slowed by public concern about electric and magnetic fields (EMF). This paper documents magnetic field measurements on an AC PV module, complementing EMF research on direct-current PV modules conducted by PG and E in 1993. Although not comprehensive, the PV EMF data indicate that 60 Hz magnetic fields (the EMF type of greatest public concern) from PV modules are comparable to, or significantly less than, those from household appliances. Given the present EMF research knowledge, AC PV module EMF may not merit considerable concern.

  3. Sex differences in episodic memory: minimal influence of estradiol.

    PubMed

    Yonker, Julie E; Eriksson, Elias; Nilsson, Lars Göran; Herlitz, Agneta

    2003-07-01

    Sex differences exist for several cognitive tasks and estrogen has been suggested to influence these differences. Eighteen men and 18 women were matched on age and estradiol level. Potential sex differences were assessed in episodic memory, semantic memory, verbal fluency, problem solving, and visuospatial ability. Significant sex differences, favoring women, were found for tasks assessing episodic memory. Correlations between estradiol level and cognitive performance were significant for face recognition in females. Since sex differences remained in verbal episodic memory tasks and face recognition despite matched levels of estradiol, circulating estradiol does not appear to be of paramount consequence for observed sex differences in episodic memory.

  4. Effect of ethynyl estradiol on the secretion of hepatic triglyceride.

    PubMed

    Weinstein, I; Seedman, S; Veldhuis, M

    1975-05-01

    The concentrations of triglyceride in the blood of female rats increased 2- and 4-fold during treatment with 5 and 15 mug/kg of ethynyl estradiol, respectively. The rate of secretion of triglyceride increased 66% over controls with livers obtained from the rats administered ethynyl estradiol. Ethynyl estradiol induced a hypocholesterolemia in the donor animals but the secretion of cholesterol into the perfusate from livers obtained from these animal was not affected. Adrenal corticosterone levels were depressed 48% in animals receivint of ethynyl estradiol on the liver or secondary to other hormonal changes.

  5. Final report on key comparison CCQM-K55.a (estradiol): An international comparison of mass fraction purity assignment of estradiol

    NASA Astrophysics Data System (ADS)

    Westwood, Steven; Josephs, Ralf; Daireaux, Adeline; Wielgosz, Robert; Davies, Stephen; Wang, Hongjie; Rodrigues, Jainana; Wollinger, Wagner; Windust, Anthony; Kang, Ma; Fuhai, Su; Philipp, Rosemarie; Kuhlich, Paul; Wong, Siu-kay; Shimizu, Yoshitaka; Pérez, Melina; Avila, Marco; Fernandes-Whaley, Maria; Prevoo, D.; de Vos, J.; Visser, R.; Archer, M.; LeGoff, Thierry; Wood, Steve; Bearden, Dan; Bedner, Mary; Boroujerdi, Arezue; Duewer, David; Hancock, Diane; Lang, Brian; Porter, Barbara; Schantz, Michele; Sieber, John; White, Edward; Wise, Stephen A.

    2012-01-01

    purity. The relative expanded uncertainties reported by laboratories having results consistent with the KCRV ranged from 0.2% to 0.8%. The review of results that were biased from the KCRV showed that two major analytical challenges are posed by the material: the measurement of its water content and controlling for related substance artefact formation during the analysis process. The results displaying a positive bias relative to the KCRV (overestimation of estradiol content) were due to underestimation of the water content of the material, while those with a negative bias (underestimation of estradiol) overestimated the total related substance impurities through a failure to detect and control for artefact formation arising from in situ oxidative dimerization of estradiol in neutral solution prior to analysis. There was however good agreement between all participants in the identification and the quantification of the individual related structure impurities actually present in the sample. The comparison also demonstrated the utility of high-field 1H NMR for both quantitative and qualitative analysis of high purity compounds. It is noted that all the participants who used qNMR as a major or contributing technique and included it as part of, combined it or confirmed it with a conventional 'mass balance' data estimate, obtained results consistent with the KCRV. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  6. The Binding Constant of Estradiol to Bovine Serum Albumin: An Upper-Level Experiment Utilizing Tritium-Labeled Estradiol and Liquid Scintillation Counting

    ERIC Educational Resources Information Center

    Peihong Liang; Adhyaru, Bhavin; Pearson, Wright L.; Williams, Kathryn R.

    2006-01-01

    The experiment used [to the third power]H-labeled estradiol to determine the binding constant of estradiol to bovine serum albumin. Estradiol must complex with serum proteins for the transport in the blood stream because of its low solubility in aqueous systems and estradiol-protein binding constant, where K[subscript B] is important to understand…

  7. The Binding Constant of Estradiol to Bovine Serum Albumin: An Upper-Level Experiment Utilizing Tritium-Labeled Estradiol and Liquid Scintillation Counting

    ERIC Educational Resources Information Center

    Peihong Liang; Adhyaru, Bhavin; Pearson, Wright L.; Williams, Kathryn R.

    2006-01-01

    The experiment used [to the third power]H-labeled estradiol to determine the binding constant of estradiol to bovine serum albumin. Estradiol must complex with serum proteins for the transport in the blood stream because of its low solubility in aqueous systems and estradiol-protein binding constant, where K[subscript B] is important to understand…

  8. Effect of endogenous androgens on 17beta-estradiol-mediated protection after spinal cord injury in male rats.

    PubMed

    Kachadroka, Supatra; Hall, Alicia M; Niedzielko, Tracy L; Chongthammakun, Sukumal; Floyd, Candace L

    2010-03-01

    Several groups have recently shown that 17beta-estradiol is protective in spinal cord injury (SCI). Testosterone can be aromatized to 17beta-estradiol and may increase estrogen-mediated protection. Alternatively, testosterone has been shown to increase excitotoxicity in models of central nervous system (CNS) injury. These experiments test the hypothesis that endogenous testosterone in male rats alters 17beta-estradiol-mediated protection by evaluating a delayed administration over a clinically relevant dose range and manipulating testicular-derived testosterone. Adult male Sprague Dawley rats were either gonadectomized or left gonad-intact prior to SCI. SCI was produced by a midthoracic crush injury. At 30 min post SCI, animals received a subcutaneous pellet of 0.0, 0.05, 0.5, or 5.0 mg of 17beta-estradiol, released over 21 days. Hindlimb locomotion was analyzed weekly in the open field. Spinal cords were collected and analyzed for cell death, expression of Bcl-family proteins, and white-matter sparing. Post-SCI administration of the 0.5- or 5.0-mg pellet improved hindlimb locomotion, reduced urinary bladder size, increased neuronal survival, reduced apoptosis, improved the Bax/Bcl-xL protein ratio, and increased white-matter sparing. In the absence of endogenous testicular-derived androgens, SCI induced greater apoptosis, yet 17beta-estradiol administration reduced apoptosis to the same extent in gonadectomized and gonad-intact male rats. These data suggest that delayed post-SCI administration of a clinically relevant dose of 17beta-estradiol is protective in male rats, and endogenous androgens do not alter estrogen-mediated protection. These data suggest that 17beta-estradiol is an effective therapeutic intervention for reducing secondary damage after SCI in males, which could be readily translated to clinical trials.

  9. Estradiol-induced promotion of hepatocarcinogenesis in medaka: Relationship of foci of cellular alteration to neoplasia

    SciTech Connect

    Cooke, J.B.; Hinton, D.E.

    1995-12-31

    In some laboratory and field studies, female fish have higher prevalences of liver tumors than do males. The authors hypothesize gender and site-specific differences in prevalence are due to variable exposures of previously initiated fish to tumor modulating compounds. Estradiol, a growth promoter, increases incidences of hepatic tumors in carcinogen-treated rainbow trout and medaka (Oryzias latipes). Estradiol also increases incidences of hepatic foci of cellular alteration (FCA) in medaka. FCA are found in subadults of tumor-bearing feral populations. Lack of knowledge about the relationship of various phenotypes of FCA to eventual tumors, however, has prevented use of FCA as a biomarker. The authors examined fate and growth of liver FCA using a 2-step, initiation-promotion protocol. Three week old medaka were exposed to 200 ppm diethylnitrosamine (DEN) for 24 hr. and then fed 0.1 ppm 17-{beta}-estradiol (E2) continuously through sampling at weeks 4--26. Percent volume of FCA and morphometric characteristics of normal and focal hepatocytes, including numerical density and average hepatocyte volume were quantified using computer-assisted stereology. E2 increased percentage of liver occupied by DEN-initiated amphophilic, basophilic and eosinophilic FCA in both sexes. Focal parameters of young, DEN-initiated and estradiol-treated medaka were not reached until much later in fish given only DEN. Non-focal hepatocytes in estradiol-treated medaka were smaller and more numerous than in DEN-only counterparts. Morphometric analysis is quantitatively tracking the fate of specific phenotypes of FCA to determine their role in progression to cancer.

  10. Estradiol and hemodynamics during ovulation induction.

    PubMed

    Veille, J C; Morton, M J; Burry, K; Nemeth, M; Speroff, L

    1986-09-01

    Left ventricular size and stroke volume increase in human pregnancy and during estrogen administration in laboratory animals. In order to determine if elevated levels of endogenous estrogens in humans produce hemodynamic changes similar to those that occur during pregnancy, 14 patients were studied during ovulation induction at day 8 +/- 2 (SD) (proliferative phase) and at day 14 +/- 4 (midcycle) of their cycles. M-mode echocardiography was carried out with the patient in the left lateral decubitus, head down and head up positions. The mean serum estradiol level was 294 +/- 234 (SD) pg ml-1 at day 8 +/- 2 (treatment day) and it increased to 1503 +/- 531 pg ml-1 at day 14 +/- 4 (cycle day) of the same cycle. This change in serum estradiol was significant (P less than 0.001), associated with an increase in left ventricle diastolic dimension of 2.3 +/- 1.1 mm (P less than 0.001). During the same time period stroke volume and cardiac index correspondingly increased. Heart rate, fractional shortening, and blood pressure did not change and systemic vascular resistance decreased. Many of the cardiovascular adaptations of pregnancy are duplicated by high levels of endogenous estrogens and these changes are evident in as few as 6 days. Thus, we conclude that changes in endogenous estrogen correlate with certain cardiovascular parameters, the most striking of which is the left ventricular size. This may be one of the adaptive mechanisms by which the maternal circulation adapts to pregnancy.

  11. Pure crystalline estradiol pellet implantation for contraception.

    PubMed

    Asch, R H; Greenblatt, R B; Mahesh, V B

    1978-01-01

    The subcutaneous implantation of estradiol pellets was found to be a simple and effective contraceptive method with good patient acceptance and minimal untoward effects. The pellets (25 mg each) were implanted through a Kearn's trocar into the abdominal wall, 2.5 to 5 cm above and parallel to Poupart's ligament. The regimen began with four pellets, and the dose was maintained or decreased by one pellet every 6 months (four, three, two, one). A potent progestogen was utilized monthly for induction of withdrawal bleeding. Altogether, 236 patients were followed for a total of 1,060 courses in 6,360 cycles (489,02 woman-years). Two pregnancies occurred during therapy. Pearl's index was 0.37. No significant alterations occurred in body weight and blood pressure. Glucose tolerance test, standard blood profiles, and Papanicolaou smears were normal during therapy. No cases of thrombophlebitis, blurred vision, headaches, gastric symptoms, or amenorrhea-galactorrhea were observed. The suppression of ovulation was confirmed by endometrial biopsies, basal body temperature, and serum follicle-stimulating hormone, luteinizing hormone, estradiol, and progesterone in a selected group of patients.

  12. The development of female sexual behavior requires prepubertal estradiol.

    PubMed

    Brock, Olivier; Baum, Michael J; Bakker, Julie

    2011-04-13

    The classic view of brain and behavioral sexual differentiation holds that the neural mechanisms controlling sexual behavior in female rodents develop in the absence of ovarian sex hormone actions. However, in a previous study, female aromatase knock-out (ArKO) mice, which cannot convert testosterone to estradiol, showed deficient male-oriented partner preference and lordosis behaviors in response to adult ovarian hormones, raising the possibility that estradiol may contribute to the development of these female sexual behaviors. In the present experiments, administering estradiol prepubertally [between postnatal day 15 (P15) and P25] significantly enhanced the ability of ArKO female mice to display lordosis behavior in response to ovarian hormones administered later in adulthood, whereas treatment with estradiol over an earlier postnatal period (P5-P15) had no such effect. Treatment of ArKO females with estradiol between P15 and P25 also rescued their later preference to approach distal cues from an intact male over an estrous female. ArKO females also displayed significantly less female-directed (male-typical) mounting behavior than wild-type control females when treated with testosterone in adulthood. Prepubertal estradiol treatment failed to reverse this deficit in ArKO females, whereas earlier postnatal estradiol augmented later mounting in both genotypes. Our results provide new evidence for an organizing role of prepubertal estradiol in the development of neural mechanisms that control female-typical sexual behavior.

  13. 21 CFR 522.2477 - Trenbolone acetate and estradiol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... acetate and 4 mg estradiol, and 1 pellet containing 29 mg tylosin tartrate) per implant dose. (C) 200 mg... containing 29 mg tylosin tartrate) per implant dose. (F) 80 mg trenbolone acetate and 16 mg estradiol (one..., and 1 pellet containing 29 mg tylosin tartrate) per implant dose. (G) 200 milligram (mg) trenbolone...

  14. 21 CFR 522.2477 - Trenbolone acetate and estradiol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... acetate and 4 mg estradiol, and 1 pellet containing 29 mg tylosin tartrate) per implant dose. (C) 200 mg... containing 29 mg tylosin tartrate) per implant dose. (F) 80 mg trenbolone acetate and 16 mg estradiol (one..., and 1 pellet containing 29 mg tylosin tartrate) per implant dose. (G) 200 milligram (mg) trenbolone...

  15. 21 CFR 522.2477 - Trenbolone acetate and estradiol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... acetate and 4 mg estradiol, and 1 pellet containing 29 mg tylosin tartrate) per implant dose. (C) 200 mg... containing 29 mg tylosin tartrate) per implant dose. (F) 80 mg trenbolone acetate and 16 mg estradiol (one..., and 1 pellet containing 29 mg tylosin tartrate) per implant dose. (G) 200 milligram (mg) trenbolone...

  16. Long-acting estrogenic responses of estradiol fatty acid esters.

    PubMed

    Vazquez-Alcantara, M A; Menjivar, M; Garcia, G A; Díaz-Zagoya, J C; Garza-Flores, J

    1989-12-01

    Estradiol esters at C-17 and C-3 with palmitic, stearic and oleic acids were chemically synthesized and then evaluated for their long-acting estrogenic responses in ovariectomized rats. The duration of the biological effects was measured after a single subcutaneous dose of 0.1 mumol of each ester and compared with those observed with 17 beta-estradiol, estradiol 3-benzoate and estradiol 17-enanthate. Vaginal citology, uterophyc action, serum gonadotropins inhibition and 17 beta-estradiol levels were measured 0, 5, 10, 20, 30 and 60 days after injection. The results disclosed that most of the estradiol derivatives evaluated exhibited a long-acting estrogenic action. However, the monoesters at C-17 showed longer effects that monoesters at C-3, while the estradiol diesters exhibited the shortest effects. In addition as shown by its low serum levels, all estradiol esters with unsaturated fatty acids show a decreased E2 absorption. The overall results indicated that esterification of E2 with long chain fatty acids provided long-acting properties to it, being higher with C-17 esters. Whether some of these compounds could be employed in substitutive endocrine therapy remains to be established.

  17. Estradiol release kinetics determine tissue response in ovariectomized rats.

    PubMed

    Otto, Christiane; Kantner, Ingrid; Nubbemeyer, Reinhard; Schkoldow, Jenny; Fuchs, Iris; Krahl, Elisabeth; Vonk, Richardus; Schüler, Christiane; Fritzemeier, Karl-Heinrich; Erben, Reinhold G

    2012-04-01

    Estrogen replacement is an effective therapy of postmenopausal symptoms such as hot flushes, bone loss, and vaginal dryness. Undesired estrogen effects are the stimulation of uterine and mammary gland epithelial cell proliferation as well as hepatic estrogenicity. In this study, we examined the influence of different estradiol release kinetics on tissue responsivity in ovariectomized (OVX) rats. Pulsed release kinetics was achieved by ip or sc administration of estradiol dissolved in physiological saline containing 10% ethanol (EtOH/NaCl) whereas continuous release kinetics was achieved by sc injection of estradiol dissolved in benzylbenzoate/ricinus oil (1+4, vol/vol). Initial 3-d experiments in OVX rats showed that pulsed ip estradiol administration had profoundly reduced stimulatory effects on the uterus and the liver compared with continuous release kinetics. On the other hand, both administration forms prevented severe vaginal atrophy. Based on these results, we compared the effects of pulsed (sc in EtOH/NaCl) vs. continuous (sc in benzylbenzoate/ricinus oil) estradiol release kinetics on bone, uterus, mammary gland, and liver in a 4-month study in OVX rats. Ovariectomy-induced bone loss was prevented by both administration regimes. However, pulsed estradiol resulted in lower uterine weight, reduced induction of hepatic gene expression, and reduced mammary epithelial hyperplasia relative to continuous estradiol exposure. We conclude that organ responsivity is influenced by different hormone release kinetics, a fact that might be exploited to reduce undesired estradiol effects in postmenopausal women.

  18. Dissipation of 17B-estradiol in composted poultry litter

    USDA-ARS?s Scientific Manuscript database

    The effects of heated composting and ambient temperature poultry waste decomposition on the fate of 17ß-estradiol and testosterone were determined in separate experiments. A mixture of poultry litter, wood chips and straw was amended with [14C]17ß-estradiol or [14C]testosterone and allowed to under...

  19. THE DEVELOPMENT OF FEMALE SEXUAL BEHAVIOR REQUIRES PREPUBERTAL ESTRADIOL

    PubMed Central

    Brock, Olivier; Baum, Michael J.; Bakker, Julie

    2011-01-01

    The classic view of brain and behavioral sexual differentiation holds that the neural mechanisms controlling sexual behavior in female rodents develop in the absence of ovarian sex hormone actions. However, in a previous study, female aromatase knockout (ArKO) mice, which cannot convert testosterone to estradiol, showed deficient male-oriented partner preference and lordosis behaviors in response to adult ovarian hormones, raising the possibility that estradiol may contribute to the development of these female sexual behaviors. In the present experiments, administering estradiol prepubertally (between postnatal days P15–P25) significantly enhanced the ability of ArKO female mice to display lordosis behavior in response to ovarian hormones administered later in adulthood whereas treatment with estradiol over an earlier postnatal period (P5–P15) had no such effect. Treatment of ArKO females with estradiol between P15–P25 also rescued their later preference to approach distal cues from an intact male over an estrous female. ArKO females also displayed significantly less female-directed (male-typical) mounting behavior than wild type control females when treated with testosterone in adulthood. Prepubertal estradiol treatment failed to reverse this deficit in ArKO females whereas earlier postnatal estradiol augmented later mounting in both genotypes. Our results provide new evidence for an organizing role of prepubertal estradiol in the development of neural mechanisms that control female-typical sexual behavior. PMID:21490197

  20. Sex reversal by estradiol in three reptilian orders.

    PubMed

    Bull, J J; Gutzke, W H; Crews, D

    1988-06-01

    Administration of exogenous estradiol caused embryos to develop ovaries rather than testes in alligators, softshell turtles, and leopard geckos. Alligators and leopard geckos are known to have environmental sex determination; softshell turtles lack both environmental sex determination and heteromorphic sex chromosomes. Sensitivity to gonadal feminization by estradiol thus appears to be widespread in amniotes.

  1. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... consists of: (1) 8 pellets, each pellet containing 25 milligrams (mg) trenbolone acetate and 3.5 mg estradiol benzoate. (2) 4 pellets, each pellet containing 25 mg trenbolone acetate and 3.5 mg estradiol...) For an implant as described in paragraph (a)(1) of this section: (A) Amount. 200 mg trenbolone...

  2. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... consists of: (1) 8 pellets, each pellet containing 25 milligrams (mg) trenbolone acetate and 3.5 mg estradiol benzoate. (2) 4 pellets, each pellet containing 25 mg trenbolone acetate and 3.5 mg estradiol...) For an implant as described in paragraph (a)(1) of this section: (A) Amount. 200 mg trenbolone...

  3. DIBROMOACETIC ACID-INDUCED ELEVATIONS OF ESTRADIOL IN THE CYCLING AND OVARIECTOMOZED/ESTRADIOL-IMPLANTED FEMALE RAT

    EPA Science Inventory

    Goldman, JM and Murr, AS. Dibromoacetic Acid-induced Elevations of Estradiol in Both Cycling and Ovariectomized / Estradiol-implanted Female Rats

    ABSTRACT
    Haloacetic acids are one of the principal classes of disinfection by-products generated by the chlorination of mun...

  4. DIBROMOACETIC ACID-INDUCED ELEVATIONS OF ESTRADIOL IN THE CYCLING AND OVARIECTOMOZED/ESTRADIOL-IMPLANTED FEMALE RAT

    EPA Science Inventory

    Goldman, JM and Murr, AS. Dibromoacetic Acid-induced Elevations of Estradiol in Both Cycling and Ovariectomized / Estradiol-implanted Female Rats

    ABSTRACT
    Haloacetic acids are one of the principal classes of disinfection by-products generated by the chlorination of mun...

  5. Effects of exposure to estradiol and estradiol plus testosterone on the Mongolian gerbil (Meriones unguiculatus) female prostate.

    PubMed

    Da Silva, Diego Augusto Lopes; Zanatelli, Marianna; Shinohara, Filipe Zardini; Góes, Rejane Maira; Dos Santos, Fernanda Cristina Alcântara; Vilamaior, Patricia Simone Leite; Taboga, Sebastião Roberto

    2013-05-01

    The female prostate is a differentiated organ found in several mammal species, including humans and rodents. This gland has been related to important functions on female reproductive biology. Although the factors, which regulate prostate's development and activity are not well known, its functionality has been related to steroid hormones. It is well established that cyclic changes of estradiol and progesterone levels promote histophysiological adaptations of the whole female body. In contrast, only a few is found about those adaptations in female prostate. Thus, this study aimed to evaluate the effect of estradiol and estradiol + testosterone association on gerbil female prostate in order to verify, which hormonal associations are necessary to its homeostasis. For this, adult females had the ovaries surgically removed. After recovering, they received estradiol and estradiol + testosterone doses through 30 days, each 48 h. The prostatic tissue underwent morphological and morphometric-estereological analysis. Hormonal restriction caused great gland involution and decreased secretory activity, aspects that were reverted by exposure to estradiol and estradiol + testosterone. However, these hormones were not able to re-establish the normal prostate histoarchitecture. The immunoreaction of steroid receptors (ER-α, ER-β, and AR) responded differently among the experimental and control groups, and PCNA assay showed a decrease in epithelial cell proliferation within groups that had hormone privation. Therefore, we conclude that estradiol and testosterone are able to influence prostate morphophysiology and the maintenance of gland homeostasis depends on a balance among these and other hormones. Copyright © 2013 Wiley Periodicals, Inc.

  6. Halogenated 17ß-estradiol surrogates: synthesis, estrogenic activity, and initial investigations of fate in soil/water systems

    USDA-ARS?s Scientific Manuscript database

    17ß-Estradiol (E2) is a natural, endocrine-disrupting, steroid hormone excreted by all vertebrates that can enter the environment from domestic animal and wildlife wastes. Multiple field studies using food animal manures as E2 sources suggest significant background concentrations of E2 (e.g., wildli...

  7. Response of dairy cattle to transient voltages and magnetic fields

    SciTech Connect

    Reinemann, D.J.; Laughlin, N.K.; Stetson, L.E.

    1995-07-01

    Stray voltages in dairy facilities have been studied since the 1970`s. Previous research using steady-state ac and dc voltages has defined cow-contact voltage levels which may cause behavior and associated production problems. This research was designed to address concerns over possible effects of transient voltages and magnetic fields on dairy cows. Dairy cows response to transient voltages and magnetic fields was measured. The waveforms of the transient voltages applied were: 5 cycles of 60-Hz ac with a total pulse time of 83 ms, 1 cycle of 60-Hz ac with a total pulse time of 16 ms, and 1 cycle of an ac square wave (spiking positive and negative) of 2-ms duration. Alternating magnetic fields were produced by passing 60-Hz ac fundamental frequency with 2nd and 3rd harmonic and random noise components in metal structures around the cows. The maximum magnetic field associated with this current flow was in excess of 4 G. A wide range of sensitivity to transient voltages was observed among cows. Response levels from 24 cows to each transient exposure were normally distributed. No responses to magnetic fields were observed.

  8. Ethinyl estradiol and 17β-estradiol in combined oral contraceptives: pharmacokinetics, pharmacodynamics and risk assessment.

    PubMed

    Stanczyk, Frank Z; Archer, David F; Bhavnani, Bhagu R

    2013-06-01

    The need to seek improved combined oral contraceptive (COC) efficacy, with fewer health risks and better acceptability, has been ongoing since the introduction of COCs more than 50 years ago. New progestin formulations combined with lower doses of ethinyl estradiol (EE), the predominant estrogenic component of COCs, have reduced the incidence of venous thromboembolism and other negative outcomes of COC treatment. Previous attempts to use endogenous 17β-estradiol (E₂) instead of EE were limited primarily by poor cycle control. The recent introduction of E₂-based formulations has renewed interest to determine if there are potential benefits of using E₂ in COCs. These formulations have been shown to have similar efficacy and cycle control as EE-based COCs. This review provides a brief summary of the pharmacology of EE and E₂, including metabolism, pharmacokinetics and pharmacodynamics, as well as adverse effects of these estrogens.

  9. The hyperventilation of cirrhosis: progesterone and estradiol effects.

    PubMed

    Lustik, S J; Chhibber, A K; Kolano, J W; Hilmi, I A; Henson, L C; Morris, M C; Bronsther, O

    1997-01-01

    Progesterone and estradiol are metabolized in the liver and are elevated in patients with cirrhosis. Progesterone stimulates ventilation by activating progesterone receptors in the central nervous system; estradiol may facilitate progesterone's actions by increasing progesterone receptors. This study evaluated whether progesterone and estradiol contribute to the respiratory alkalosis common in cirrhotic patients. Arterial blood gases and progesterone and estradiol levels were obtained in 50 patients with cirrhosis. Multiple linear regression revealed a statistically significant correlation between PaCO2 and progesterone and estradiol (r = .54, P < .05). Patients with severe hyperventilation (PaCO2 < or = 30 mm Hg) had statistically higher levels of progesterone and estradiol than did patients with mild hyperventilation (30 < PaCO2 < or = 35) or normal ventilation (PaCO2 > 35) (P < .05). Although the progesterone levels were two orders of magnitude lower than those associated with hyperventilation in pregnant patients, the increased ventilatory effect may be because of the altered blood-brain barrier (BBB) present in cirrhotic patients. Progesterone and estradiol appear to contribute to the hyperventilation in cirrhotic patients.

  10. Vasomotor symptoms, estradiol levels and cardiovascular risk profile in women.

    PubMed

    Gast, Gerrie-Cor M; Samsioe, Göran N; Grobbee, Diederick E; Nilsson, Peter M; van der Schouw, Yvonne T

    2010-07-01

    We investigated whether menopausal vasomotor symptoms (VMS) are related to an adverse cardiovascular risk profile. Furthermore, we examined the association between estradiol levels and VMS, and whether an association between VMS and cardiovascular risk factors can be explained by estradiol levels. We used data from a Swedish population-based sample of 5857 women, aged 50-64 years. Data on VMS and potential confounders were collected by questionnaires. Body mass index (BMI), waist hip ratio (WHR), glucose, blood pressure, lipid profile and estradiol levels were measured. Symptoms of flushing/sweats were reported by 55% and sweats by 31% of all women. Estradiol concentrations were significantly lower in women with VMS. After multivariate adjustment, women with symptoms of sweats had a statistically significantly higher BMI, waist hip ratio, total cholesterol level, LDL level, triglycerides level, glucose level, systolic and diastolic blood pressure. These patterns did not change after correction for estradiol. The associations between flushing/sweats combined and cardiovascular risk factors were less pronounced. Women with VMS have a less favorable cardiovascular risk profile. Although estradiol levels were significantly lower among women with VMS, the increased cardiovascular risk profile cannot be explained by circulating estradiol levels. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  11. Nongenomic effects of estradiol on aggression under short day photoperiods

    PubMed Central

    Laredo, Sarah A.; Landeros, Rosalina Villalon; Dooley, James C.; Steinman, Michael Q.; Orr, Veronica; Silva, Andrea L.; Crean, Katie K.; Robles, Cindee F.; Trainor, Brian C.

    2013-01-01

    In several vertebrate species, the effects of estrogens on male aggressive behavior can be modulated by environmental cues. In song sparrows and rodents, estrogens modulate aggression in the nonbreeding season or winter-like short days, respectively. The behavioral effects of estrogens are rapid, which generally is considered indicative of nongenomic processes. The current study further examined the hypothesis that estradiol acts nongenomically under short days by utilizing a protein synthesis inhibitor, cycloheximide (CX). Mice were housed in either short or long day photoperiods, and treated with an aromatase inhibitor. One hour before resident-intruder testing mice were injected with either CX or saline vehicle, and 30 minutes later were treated orally with either cyclodextrin conjugated estradiol or vehicle. Under short days, mice treated with estradiol showed a rapid decrease in aggressive behavior, independent of CX administration. CX alone had no effect on aggression. These results show that protein synthesis is not required for the rapid effects of estradiol on aggression, strongly suggesting that these effects are mediated by nongenomic processes. We also showed that estradiol suppressed c-fosimmunoreactivity in the caudal bed nucleus of the stria terminalis under short days. No effects of estradiol on behavior or c-fos expression were observed in mice housed under long days. Previously we had also demonstrated that cage beddinginfluenced the directional effects of estrogens on aggression. Here, we show that the phenomenon of rapid action of estradiol on aggression under short days is a robust result that generalizes to different bedding conditions. PMID:23763907

  12. Involvement of CART in estradiol-induced anorexia.

    PubMed

    Dandekar, Manoj P; Nakhate, Kartik T; Kokare, Dadasaheb M; Subhedar, Nishikant K

    2012-01-18

    Since estradiol exercises inhibitory effect on food intake, we wanted to find out if this influence of estradiol is mediated by cocaine- and amphetamine-regulated transcript peptide (CART), a well established anorectic agent in the brain. Ovariectomized (OVX) rats, replaced with estradiol to produce estrous-phase like conditions, showed a significant decrease in food intake as compared with that in OVX controls. Intracerebroventricular (icv) administration of CART (0.5-1 μg/rat) to OVX rats, resulted in a dose-dependent reduction in the food intake. The lower dose (0.25 μg) had no effect, and was considered subeffective. In estradiol replaced OVX rats, CART at subeffective dose, further reduced food intake. However, CART failed to reduce food intake in estradiol replaced OVX rats pretreated with anti-estrogenic agent tamoxifen (3 mg/kg, subcutaneous). Administration of CART antibody (1:500 dilution/rat, i.c.v.) significantly attenuated estradiol-induced anorexia in the OVX rats. While estradiol replacement significantly increased CART-immunoreactivity in the cells/fibers of paraventricular nucleus (PVN) of OVX rats, fibers in the anteroventral periventricular nucleus (AVPV), and cells/fibers in the arcuate nucleus (ARC) showed considerable reduction. These changes were attenuated following concurrent injection of tamoxifen to the estradiol replaced OVX rats. However, CART-immunoreactive cells/fibers in the periventricular area did not respond to any of the treatments. We suggest that estradiol treatment might influence the hypothalamic CART system in a site specific manner. While increased CART activity in the PVN might produce anorexia, reduction of CART in ARC and AVPV might represent a compensatory homeostatic response. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Endotoxin disrupts the estradiol-induced luteinizing hormone surge: interference with estradiol signal reading, not surge release.

    PubMed

    Battaglia, D F; Beaver, A B; Harris, T G; Tanhehco, E; Viguié, C; Karsch, F J

    1999-06-01

    Three experiments were conducted to investigate whether the immune/inflammatory stimulus endotoxin disrupts the estradiol-induced LH surge of the ewe. Ovariectomized sheep were set up in an artificial follicular phase model in which luteolysis is simulated by progesterone withdrawal and the follicular phase estradiol rise is reproduced experimentally. In the first experiment, we tested the hypothesis that endotoxin interferes with the estradiol-induced LH surge. Ewes were either infused with endotoxin (300 ng/kg/h, i.v.) for 30 h beginning at onset of a 48-h estradiol stimulus or sham infused as a control. Endotoxin significantly delayed the time to the LH surge (P < 0.01), but did not alter surge amplitude, duration, or incidence. The second experiment tested the hypothesis that the delaying effects of endotoxin on the LH surge depend on when endotoxin is introduced relative to the onset of the estradiol signal. Previous work in the ewe has shown that a 14-h estradiol signal is adequate to generate GnRH and LH surges, which begin 6-8 h later. Thus, we again infused endotoxin for 30 h, but began it 14 h after the onset of the estradiol signal. In contrast to the first experiment, endotoxin given later had no effect on any parameter of the LH surge. In the third experiment, we tested the hypothesis that endotoxin acts during the first 14 h to disrupt the initial activating effects of estradiol. Estradiol was delivered for just 14 h, and endotoxin was infused only during this time. Under these conditions, endotoxin blocked the LH surge in five of eight ewes. In a similar follow-up study, endotoxin again blocked the LH surge in six of seven ewes. We conclude that endotoxin can disrupt the estradiol-induced LH surge by interfering with the early activating effects of the estradiol signal during the first 14 h (reading of the signal). In contrast, endotoxin does not disrupt later stages of signal processing (i.e. events during the interval between estradiol signal

  14. Feasibility of using near-infrared spectroscopy for rapid quantification of 17β-estradiol sorption coefficients in soil.

    PubMed

    Singh, Baljeet; Malley, Diane F; Farenhorst, Annemieke; Williams, Phil

    2012-10-10

    Livestock manure contains natural steroid hormones, with the most potent being 17β-estradiol. The transport of steroid hormones from agricultural fields to adjacent water bodies can result in 17β-estradiol environmental contamination impacting aquatic organisms. Sorption coefficients are useful input into models that estimate risk of water contamination. The feasibility of applying near-infrared spectroscopy (NIRS) for determining sorption coefficients of 17β-estradiol in soil was investigated for two irregular undulating to hummocky terrain landscapes in Manitoba and Saskatchewan, Canada. A total of 609 soil samples in 140 soil profiles were collected from several horizons to a depth of 1 m. Air-dried and sieved (2 mm) soil samples were analyzed for soil organic carbon (SOC), soil pH, and soil texture. Sorption coefficients of 17β-estradiol were determined by a batch equilibrium process. Spectral data were collected from soil samples (25 g) using two instruments, the 45VISNIR Zeiss Corona (wavelength range 700-1690 nm) and the Foss NIRSystems 6500 (wavelength range 1100-2500 nm). Regardless of the site and instrument, the predictive models were excellent for both SOC and 17β-estradiol sorption coefficients. The data thus generated can be used as input parameters in fate models for efficient risk assessments and decision-making programs for environmental safety where soils are at risk of receiving inputs of 17β-estradiol. Calibration results for soil pH were also adequate with Corona outperforming the Foss instrument. Soil texture predictions were relatively unsuccessful regardless of the instrument and site.

  15. [Photodegradation of 17beta-estradiol induced by Chlorella vulgaris].

    PubMed

    Ge, Liyun; Deng, Huanhuan; Wu, Feng; Weng, Yue; Deng, Nansheng

    2004-07-01

    The study showed that when exposed to high-pressure Hg-lamp (HPML, lambda(max) > or = 365 nm), and the concentration of Chlorella vulgaris was 4.0 x 10(10) cells x L(-1), the photodegradation rate of 17beta-estradiol could reach to 37%. When the concentration of Chlorella vulgaris was 4.2 x 10(10) cells x L(-1), the photodegradation of 1.5 x 10(-5) - 6.0 x 10(-5) mol x L(-1) 17beta-estradiol in aqueous solutions was pseudo-first order reaction. Increasing the initial concentration of 17beta-estradiol could lower its photodegradation rate. The influence of light intension and Chlorella vulgaris concentration on the photodegradation of 17beta-estradiol was also studied in this paper.

  16. 3D model of amphioxus steroid receptor complexed with estradiol

    SciTech Connect

    Baker, Michael E.; Chang, David J.

    2009-08-28

    The origins of signaling by vertebrate steroids are not fully understood. An important advance was the report that an estrogen-binding steroid receptor [SR] is present in amphioxus, a basal chordate with a similar body plan as vertebrates. To investigate the evolution of estrogen-binding to steroid receptors, we constructed a 3D model of amphioxus SR complexed with estradiol. This 3D model indicates that although the SR is activated by estradiol, some interactions between estradiol and human ER{alpha} are not conserved in the SR, which can explain the low affinity of estradiol for the SR. These differences between the SR and ER{alpha} in the steroid-binding domain are sufficient to suggest that another steroid is the physiological regulator of the SR. The 3D model predicts that mutation of Glu-346 to Gln will increase the affinity of testosterone for amphioxus SR and elucidate the evolution of steroid-binding to nuclear receptors.

  17. Neuroprotective effects of estradiol-17beta: implications for psychiatric disorders.

    PubMed

    Kölsch, H; Rao, M L

    2002-11-01

    Estradiol-17beta is the most potent female sex hormone. In addition to its role in the control of primary and secondary sexual characteristics, it also influences the development of the brain. Furthermore, estradiol-17beta possesses neuroprotective properties that are mediated via receptor action and also independently of receptors. Several processes that are regulated by estradiol-17beta might influence the expression of Alzheimer's disease and schizophrenia. Differences between the sexes have been described in both disorders, and it has been suggested that these may be due to the action of oestrogens. Long-term oestrogen replacement has proved to be beneficial in the prevention and treatment of Alzheimer's disease and schizophrenia. The results, however, are controversial. Preliminary in vitro and in vivo findings, which are summarised in this review, encourage further studies with estradiol-17beta or its analogues as potential adjunctive interventions particularly in "negative syndrome" schizophrenia and in Alzheimer's disease.

  18. Estradiol and cognitive function: Past, present and future

    PubMed Central

    Luine, Victoria N.

    2014-01-01

    A historical perspective on estradiol’s enhancement of cognitive function is presented, and research, primarily in animals, but also in humans, is reviewed. Data regarding the mechanisms underlying the enhancements are discussed. Newer studies showing rapid effects of estradiol on consolidation of memory through membrane interactions and activation of inter-cellular signaling pathways are reviewed as well as studies focused on traditional genomic mechanisms. Recent demonstrations of intra-neuronal estradiol synthesis and possible actions as a neurosteroid to promote memory are discussed. This information is applied to the critical issue of the current lack of effective hormonal (or other) treatments for cognitive decline associated with menopause and aging. Finally, the critical period hypothesis for estradiol effects is discussed along with novel strategies for hormone/drug development. Overall, the historical record documents that estradiol positively impacts some aspects of cognitive function, but effective therapeutic interventions using this hormone have yet to be realized. PMID:25205317

  19. Free estradiol and sex hormone-binding globulin.

    PubMed

    Rosner, William

    2015-07-01

    SHBG is a plasma protein that participates in the regulation of free estradiol and free testosterone in plasma. We discuss the concept of the nature of a free estradiol and how best to ascertain its value. It can be measured or calculated; the ways in which this can be done are explored along with the advantages and disadvantages of each. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Fate and transport of 17beta-estradiol in soil-water systems.

    PubMed

    Casey, Francis X M; Larsen, Gerald L; Hakk, Heldur; Simůnek, Jiri

    2003-06-01

    Over the past several years, there has been an increase in concern regarding reproductive hormones in the environment To date, there exists limited research on the fate and transport of these chemicals in the environment. In this study, a series of laboratory batch sorption and miscible-displacement experiments were done using radiolabeled [14C]17beta-estradiol. The 17beta-estradiol concentrations that were used were similar to those found in manures that are applied to field soils. Equilibrium batch experiments indicated high sorption affinity with correlations to mineral particle size and organic matter content. The sorption affinity appeared to be associated with the surface area and/or the cation-exchange capacity of the soil. The miscible-displacement breakthrough curves indicated chemical nonequilibrium transport, and a single highly polar metabolite was present in the column effluent along with sporadic and trace detections of estriol. Sorbed to the soil within the column were found 17beta-estradiol, estrone, and trace and sporadic detections of estriol. Two chemical nonequilibrium, miscible-displacement models were used to describe the column breakthrough curves; one without transformations and the other with transformations. Both models resulted in excellent descriptions of the data, which indicated nonunique solutions and less confidence in the parameter estimates. Nonetheless, the modeling and experimental results implied that degradation/transformation occurred in the sorbed phase and was rapid. Also, both models indicated that sorption was fully kinetic.

  1. Analysis of the 60-Hz power system at KSC: The Orsino substation

    NASA Technical Reports Server (NTRS)

    Kalu, Alex O.

    1989-01-01

    An analysis of the Orsino Substation, a component (50 percent) of the 60-Hertz electric power system at the Kennedy Space Center, is presented. Presented here are separate single-line diagrams of the sixteen feeder circuits to permit easy access to information on the individual feeders for future planning. The load condition of each feeder and load break switch are presented and a heuristic reliability analysis of the system is performed. Information is given about the system fashion useful for decision making purposes. The beauty of it is in the simplified manner by which information about the system can be obtained.

  2. Biological effects of ELF (extremely-low-frequency) electric and magnetic fields

    SciTech Connect

    Anderson, L.E.

    1989-10-01

    Studies have been conducted at the Pacific Northwest Laboratory to examine extremely-low-frequency (ELF) electromagnetic fields for possible biological effects in animals. Two areas of investigation are reported here: (1) studies on the nervous system, including behavior and neuroendocrine function, and (2) experiments on cancer development in animals. In behavioral experiments, preliminary data suggest that short term memory may be affected in albino rats exposed to combined ELF and static magnetic fields. Neuroendocrine studies were conducted to demonstrate an apparent stress-related response in rats exposed to 60-Hz electric fields. Finally, using a chemically-induced mammary tumor model, experiments were conducted in which rats, chronically exposed to 60-Hz electric fields, showed an enhancement in the number of tumors per tumor bearing animal.

  3. Association Between Preovulatory Concentrations of Estradiol and Expression of Uterine Milk Protein Precursor, Inhibin Beta A, Period 1, Proenkephalin, and Receptors for Oxytocin, Progesterone, and Estradiol

    USDA-ARS?s Scientific Manuscript database

    Eliminating the preovulatory surge of estradiol decreased uterine weight, uterine protein, RNA to DNA ratio, rate of protein synthesis, and embryo survival following embryo transfer in sheep. Furthermore, cows that did not exhibit standing estrus (decreased preovulatory concentrations of estradiol) ...

  4. ESTRADIOL RAPIDLY MODULATES ODOR RESPONSES IN MOUSE VOMERONASAL SENSORY NEURONS

    PubMed Central

    CHERIAN, S.; LAM, Y. WAI; MCDANIELS, I.; STRUZIAK, M.; DELAY, R. J.

    2014-01-01

    In rodents, many social behaviors are driven by the sense of smell. The vomeronasal organ (VNO), part of the accessory olfactory system mediates many of these chemically driven behaviors. The VNO is heavily vascularized, and is readily accessible to circulating peptide or steroid hormones. Potentially, this allows circulating hormones to alter behavior through modulating the output of the primary sensory neurons in the VNO, the vomeronasal sensory neurons (VSNs). Based on this, we hypothesized that steroid hormones, in particular 17β-estradiol, would modulate activity of VSNs. In this paper, we show that the estrogen receptors, GPR30 and ERα, were present in VSNs and that estradiol may be synthesized locally in the VNO. Our results also showed that 17β-estradiol decreased responses of isolated VSNs to dilute urine, a potent natural stimulus, with respect to current amplitudes and depolarization. Further, 17β-estradiol increased the latency of the first action potential (AP) and the AP amplitude. Additionally, calcium responses to sulfated steroids (present in the low molecular weight fraction of urine) that act as ligands for apical vomeronasal receptors were decreased by 17β-estradiol. In conclusion, we show that estradiol modulates odorant responses mediated by VSNs and hence paves the way for future studies to better understand the mechanisms by which odorant mediated behavior is altered by endocrine status of the animal. PMID:24680884

  5. Estradiol Increases Mucus Synthesis in Bronchial Epithelial Cells

    PubMed Central

    Tam, Anthony; Wadsworth, Samuel; Dorscheid, Delbert; Man, Shu-Fan Paul; Sin, Don D.

    2014-01-01

    Airway epithelial mucus hypersecretion and mucus plugging are prominent pathologic features of chronic inflammatory conditions of the airway (e.g. asthma and cystic fibrosis) and in most of these conditions, women have worse prognosis compared with male patients. We thus investigated the effects of estradiol on mucus expression in primary normal human bronchial epithelial cells from female donors grown at an air liquid interface (ALI). Treatment with estradiol in physiological ranges for 2 weeks caused a concentration-dependent increase in the number of PAS-positive cells (confirmed to be goblet cells by MUC5AC immunostaining) in ALI cultures, and this action was attenuated by estrogen receptor beta (ER-β) antagonist. Protein microarray data showed that nuclear factor of activated T-cell (NFAT) in the nuclear fraction of NHBE cells was increased with estradiol treatment. Estradiol increased NFATc1 mRNA and protein in ALI cultures. In a human airway epithelial (1HAE0) cell line, NFATc1 was required for the regulation of MUC5AC mRNA and protein. Estradiol also induced post-translational modification of mucins by increasing total fucose residues and fucosyltransferase (FUT-4, -5, -6) mRNA expression. Together, these data indicate a novel mechanism by which estradiol increases mucus synthesis in the human bronchial epithelium. PMID:24964096

  6. Social regulation of plasma estradiol concentration in a female anuran.

    PubMed

    Lynch, Kathleen S; Wilczynski, Walter

    2006-06-01

    The behavior of an individual within a social aggregation profoundly influences behavior and physiology of other animals within the aggregation in such a way that these social interactions can enhance reproductive success, survival and fitness. This phenomenon is particularly important during the breeding season when males and female must synchronize their reproductive efforts. We examined whether exposure to conspecific social cues can elevate sex steroid levels, specifically estradiol and androgens, in female túngara frogs (Physalaemus pustulosus). We compared plasma estradiol and androgen concentrations in wild-caught females before and after exposure to either natural mate choruses or random tones. After exposure to mate choruses for 10 consecutive nights, estradiol concentrations were significantly elevated whereas there was no significant elevation in estradiol concentrations in the group of females exposed to random tones for 10 nights. Plasma androgen concentrations were not significantly changed after exposure to either natural mate choruses or random tones for 10 consecutive nights. Social modulation of estradiol concentrations may be important in maintaining a female's reproductive state while males are chorusing. To our knowledge, this is the first study to demonstrate social regulation of estradiol concentration in female anurans.

  7. Conversion of estrone to estradiol in male fathead minnows ...

    EPA Pesticide Factsheets

    Estrogens are frequently observed in aquatic environments associated with anthropogenic influence, such as agricultural runoff and wastewater treatment effluent. While 17â-estradiol (E2) is the most potent naturally-occurring estrogen, estrone (E1) is often found at higher environmental concentrations. However, exogenous sources of E1 could potentially be converted to the more potent E2 through the action of endogenous 17â-hydroxysteroid dehydrogenase activity, specifically, the 17â-hydroxysteroid dehydrogenase type 1 isoform (HSD17B1). Observation of increased plasma E2 concentrations without measureable changes in aromatase (cytochrome P45019a) expression in male fish caged in ambient waters containing elevated concentrations of E1, but low or non-detectable concentrations of E2, suggested this may be occurring in the field. If so, exogenous E1 may have a greater impact on reproductive function in aquatic vertebrates than previously assumed. The present study was conducted to evaluate this hypothesis. Male fathead minnows (Pimephales promelas) exposed to aqueous concentrations of 16.7, 50, and 150 ng E1/L in the laboratory exhibit significantly (p<0.05) elevated plasma E2 concentrations relative to control. Plasma testosterone (T) was elevated at a low E1 exposure concentration (1.8 ng E1/L) and depressed at the highest level of exposure (150 ng E1/L). Additionally, vitellogenin (VTG) mRNA expression was significantly elevated at concentrations of 50 and 10

  8. Conversion of estrone to estradiol in male fathead minnows ...

    EPA Pesticide Factsheets

    Estrogens are frequently observed in aquatic environments associated with anthropogenic influence, such as agricultural runoff and wastewater treatment effluent. While 17â-estradiol (E2) is the most potent naturally-occurring estrogen, estrone (E1) is often found at higher environmental concentrations. However, exogenous sources of E1 could potentially be converted to the more potent E2 through the action of endogenous 17â-hydroxysteroid dehydrogenase activity, specifically, the 17â-hydroxysteroid dehydrogenase type 1 isoform (HSD17B1). Observation of increased plasma E2 concentrations without measureable changes in aromatase (cytochrome P45019a) expression in male fish caged in ambient waters containing elevated concentrations of E1, but low or non-detectable concentrations of E2, suggested this may be occurring in the field. If so, exogenous E1 may have a greater impact on reproductive function in aquatic vertebrates than previously assumed. The present study was conducted to evaluate this hypothesis. Male fathead minnows (Pimephales promelas) exposed to aqueous concentrations of 16.7, 50, and 150 ng E1/L in the laboratory exhibit significantly (p<0.05) elevated plasma E2 concentrations relative to control. Plasma testosterone (T) was elevated at a low E1 exposure concentration (1.8 ng E1/L) and depressed at the highest level of exposure (150 ng E1/L). Additionally, vitellogenin (VTG) mRNA expression was significantly elevated at concentrations of 50 and 10

  9. Hypothesis: The risk of childhood leukemia is related to combinations of power-frequency and static magnetic fields

    SciTech Connect

    Bowman, J.D. |; Thomas, D.C.; London, S.J.; Peters, J.M.

    1995-05-01

    The authors present a hypothesis that the risk of childhood leukemia is related to exposure to specific combinations of static and extremely-low-frequency (ELF) magnetic fields. Laboratory data from calcium efflux and diatom mobility experiments were used with the gyromagnetic equation to predict combinations of 60 Hz and static magnetic fields hypothesized to enhance leukemia risk. The laboratory data predicted 19 bands of the static field magnitude with a bandwidth of 9.1 {mu}T that, together with 60 Hz magnetic fields, are expected to have biological activity. The authors then assessed the association between this exposure metric and childhood leukemia using data from a case-control study in Los Angeles County. ELF and static magnetic fields were measured in the bedrooms of 124 cases determined from a tumor registry and 99 controls drawn from friends and random digit dialing. Although no association was found for childhood leukemia in relation to measured ELF or static magnetic fields alone, an increasing trend of leukemia risk with measured ELF fields was found for subjects within these static field bands. When the 60 Hz magnetic fields were assessed according to the Wertheimer-Leeper code for wiring configurations, leukemia risks were again greater with the hypothesized exposure conditions. Although the risk estimates are based on limited magnetic field measurements for a small number of subjects, these findings suggest that the risk of childhood leukemia may be related to the combined effects of the static and ELF magnetic fields.

  10. Estradiol valerate and tibolone: effects on memory.

    PubMed

    Aguiar, R B de; Dickel, O E; Cunha, R W; Monserrat, J M; Barros, D M; Martinez, P E

    2006-12-01

    This study investigated the effects of estradiol valerate (EV) and tibolone (TB) treatments on some memory parameters of ovariectomized young (2 months), adult (8 months) and old (20 months) female rats. A Sham-operated group was used as control and the animals were treated daily, by oral gavage, with saline (Sham and placebo NR group), EV (0.3 mg/kg) or TB (0.5 or 1 mg/kg, TB1 and TB2, respectively). In step-down inhibitory avoidance task, the latency of old TB2-treated females in the short-term test was significantly inferior (p<0.05), compared to TB2 adults. In the elevated plus maze, adult NR females spent significantly less time (p<0.05) in the open arms as compared with EV and TB2-treated animals. Additionally, adult TB2-treated females spent significantly less time in the closed arms compared to Sham, NR and TB1 groups. Finally, in the water maze retention test, young TB1-treated animals performed worse when compared to Sham, EV and TB2 females. In the old animals, EV treatment hampered subject performance as compared to all other treatments. Taken together, these results indicate that ovarian hormones differently affect female memory in an age-dependent manner.

  11. The effects of inverter magnetic fields on early seed germination of mung beans.

    PubMed

    Huang, Hsin-Hsiung; Wang, Show-Ran

    2008-12-01

    The biological effects of extremely low frequency magnetic fields (ELF MFs) on living organisms have been explored in many studies. Most of them demonstrate the biological effects caused by 50/60 Hz magnetic fields or pulsed magnetic fields. However, as the development of power electronics flourishes, the magnetic fields induced are usually in other different waveforms. This study aims to assess the effects of magnetic fields generated by inverter systems on the early growth of plants using mung beans as an example. In the experiment, an inverter which can produce sinusoidal pulsed width modulation (SPWM) voltages was used to drive 3 specially made circular coils and an AC motor. Six SPWM voltages with different fundamental frequencies (10, 20, 30, 40, 50, and 60 Hz) set on the inverter drive the circuit to produce the specific kinds of MFs. The results indicate that the magnetic field induced by a 20 or 60 Hz SPWM voltage has an enhancing effect on the early growth of mung beans, but the magnetic fields induced by SPWM voltages of other frequencies (30, 40, and 50 Hz) have an inhibitory effect, especially at 50 Hz.

  12. ELF Communications System Ecological Monitoring Program: Electromagnetic Field Measurements and Engineering Support--1989

    DTIC Science & Technology

    1990-10-01

    1985. It also allowed measurements to be taken with the NRTF-Clam Lake operating both at its secondary frequency of 44 Hz and at its primary frequency...EM fields affect vertebrate metabolism , nor which aspects of 3 exposure (i.e., intensity, duration, or both) could be important. The unmitigated 60 Hz...nominally on the same order of magnitude as the 76 Hz field values at the treatment sites during 150 ampere operation. Prior to 1990 metabolic studies

  13. Neural response dynamics of spiking and local field potential activity depend on CRT monitor refresh rate in the tree shrew primary visual cortex.

    PubMed

    Veit, Julia; Bhattacharyya, Anwesha; Kretz, Robert; Rainer, Gregor

    2011-11-01

    Entrainment of neural activity to luminance impulses during the refresh of cathode ray tube monitor displays has been observed in the primary visual cortex (V1) of humans and macaque monkeys. This entrainment is of interest because it tends to temporally align and thus synchronize neural responses at the millisecond timescale. Here we show that, in tree shrew V1, both spiking and local field potential activity are also entrained at cathode ray tube refresh rates of 120, 90, and 60 Hz, with weakest but still significant entrainment even at 120 Hz, and strongest entrainment occurring in cortical input layer IV. For both luminance increments ("white" stimuli) and decrements ("black" stimuli), refresh rate had a strong impact on the temporal dynamics of the neural response for subsequent luminance impulses. Whereas there was rapid, strong attenuation of spikes and local field potential to prolonged visual stimuli composed of luminance impulses presented at 120 Hz, attenuation was nearly absent at 60-Hz refresh rate. In addition, neural onset latencies were shortest at 120 Hz and substantially increased, by ∼15 ms, at 60 Hz. In terms of neural response amplitude, black responses dominated white responses at all three refresh rates. However, black/white differences were much larger at 60 Hz than at higher refresh rates, suggesting a mechanism that is sensitive to stimulus timing. Taken together, our findings reveal many similarities between V1 of macaque and tree shrew, while underscoring a greater temporal sensitivity of the tree shrew visual system.

  14. Enhanced osteoblast proliferation and collagen gene expression by estradiol

    SciTech Connect

    Ernest, M.; Schmid, Ch.; Froesch, E.R. )

    1988-04-01

    Estrogens play a crucial role in the development of postmenopausal osteoporosis. However, the mechanism by which estrogens exert their effects on bone is unknown. To examine possible direct effects of 17{beta}-estradiol on bone-forming cells, the authors used pure rat osteoblast-like cells in vitro as a model. Osteoblast-like cells prepared from calvaria of newborn rats were cultured serum-free in methylcellulose-containing medium for 21 days. Osteoblast-like cells proliferate selectively into clonally derived cell clusters of spherical morphorlogy. 17{beta}-Estradiol at concentrations of 0.1 nM and 1 nM enhanced osteoblast-like cell proliferation by 41% and 68% above vehicle-treated controls. The biologically inactive stereoisomer 17{alpha}-estradiol (same concentrations) had no effect. Moreover, the antiestrogen tamoxifen abolished the stimulation of osteoblast-like cell proliferation by 17{beta}-estradiol. After 21 days of culture, RNA was prepared and analyzed in a dot-hybridization assay for the abundance of pro{alpha}1(I) collagen mRNA. Steady-state mRNA levels were increased in cultures treated with 17{beta}-estradiol in a dose-dependent manner with maximal stimulation at 1 nM and 10 nM. At the same concentrations, the percentage of synthesized protein (labeled by ({sup 3}H)proline pulse) that was digestible by collagenase was increased, indicating that 17{beta}-estradiol acts as pretranslational levels to enhance synthesis of bone collagen. These data show that the osteoblast is a direct target for 17{beta}-estradiol.

  15. Urinary hydroxypyrene and estradiol in an occupationally exposed "outdoor" population.

    PubMed

    Sancini, A; Montuori, L; Chighine, A; Caciari, T; Giubilati, R; Sacco, C; Ponticiello, B G; Samperi, I; Tomei, G; Tomei, F; Rosati, M V

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are widely present in the air pollution. The urinary hydroxypyrene (1-HOPu) is considered the main biological biomarker currently available to measure the exposure to PAH. It is supposed responsible of an increase of estradiol levels in males. Aim of this study is to verify whether there is a relation between 1-HOPu and plasmatic estradiol in non-smoker male workers. The study was conducted on a sample of 122 non-smoker policemen in a large Italian city; we monitored their levels of 1-HOPu and the values of estradiol. The sample was divided into three groups according to the levels of urinary hydroxypyrene. The indices of correlation (r) and multiple linear regression (β), between levels of 1-HOPu and estradiol were calculated. It was also calculated the student's t-test among the groups to check the differences. We found statistically significant correlations and multivariate linear regressions between 1-HOPu and estradiol in the total sample and in group III (levels of 1-HOPu above the 75th percentile). The average levels of estradiol in group III was statistically and significantly higher than in the group I (levels of 1-HOPu below the 25th percentile) and group II (levels 1-HOPu between 25th and the 75th percentile). 1-HOPu in non-smoker male workers is related with an increase of plasmatic estradiol. We believe that PAHs, of which 1-HOPu is the main biomarker, can interact with the hypothalamic-pituitary axis. The preliminary results suggest that the topic needs further research on male and female as well.

  16. 17β-Estradiol enhances sulforaphane cardioprotection against oxidative stress.

    PubMed

    Angeloni, Cristina; Teti, Gabriella; Barbalace, Maria Cristina; Malaguti, Marco; Falconi, Mirella; Hrelia, Silvana

    2017-01-12

    The lower incidence of ischemic heart disease in female with respect to male gender suggests the possibility that female sex hormones could have specific effects in cardiovascular protection. 17β-Estradiol is the predominant premenopausal circulating form of estrogen and has a protective role on the cardiovascular system. Recent evidences suggest that gender can influence the response to cardiovascular medications; therefore, we hypothesized that sex hormones could also modulate the cardioprotective effects of nutraceutical compounds, such as the isothiocyanate sulforaphane, present in Brassica vegetables. This study was designed to explore the protective effects of sulforaphane in the presence of 17β-estradiol against H2O2-induced oxidative stress in primary cultures of rat cardiomyocytes. Interestingly, 17β-estradiol enhanced sulforaphane protective activity against H2O2-induced cell death with respect to sulforaphane or 17β-estradiol alone as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyl-tetrazolium bromide and lactate dehydrogenase assays. Moreover, 17β-estradiol boosted sulforaphane ability to counteract oxidative stress, reducing intracellular reactive oxygen species and 8-hydroxy-2'-deoxyguanosine levels and increasing the expression of phase II enzymes. Using specific antagonists of estrogen receptor α and β, we observed that these effects are not mediated by estrogen receptors. Otherwise, ERK1/2 and Akt signaling pathways seem to be involved, as the presence of specific inhibitors of these kinases reduced the protective effect of sulforaphane in the presence of 17β-estradiol. Sulforaphane and 17β-estradiol co-treatment counteracted cell morphology alterations induced by H2O2 as evidenced by transmission electron microscopy. Our results demonstrated, for the first time, that estrogens could enhance sulforaphane protective effects, suggesting that nutraceutical efficacy might be modulated by sex hormones.

  17. Estradiol-sertraline synergy in ovariectomized rats.

    PubMed

    Sell, Stacy L; Craft, Rebecca M; Seitz, Patricia K; Stutz, Sonja J; Cunningham, Kathryn A; Thomas, Mary L

    2008-09-01

    This study investigated estradiol (E(2)) modulation of the antidepressant effects of a selective serotonin (5-HT) reuptake inhibitor (SSRI; sertraline) and a tricyclic antidepressant (imipramine) as measured by the forced swim test (FST) followed by assessment of gene and protein expression for the 5-HT transporter (SERT) and multiple 5-HT receptors. Female Sprague-Dawley rats were ovariectomized (OVX) and two-thirds of the rats received E(2) implants (OVE). 4 weeks later, implants were withdrawn in half of the OVE rats (OVW) to capture a time point when E(2) levels were rapidly declining. Rats in each hormone group were treated with vehicle, sertraline (10 mg/kg) or imipramine (10 mg/kg), 24, 5 and 1h before the FST. Immediately after the FST, midbrain, hippocampus and prefrontal cortex tissue was removed and frozen for analysis of gene expression via quantitative real-time PCR (midbrain tissue) and protein expression via Western blot (prefrontal cortex and hippocampal tissue). In the FST, sertraline decreased immobility and increased swimming in OVE rats, as well as increased swimming in OVW rats. In contrast, no sertraline effect was observed in OVX rats. Rats treated with imipramine showed increased climbing but no changes in immobility or swimming. No changes in protein expression were detected in any treatment group. However, in vehicle-treated rats, E(2) increased midbrain SERT mRNA expression, with no effect on midbrain mRNA for the 5-HT receptors. In sertraline-treated rats, E(2) decreased 5-HT(2A) receptor mRNA, and E(2)-withdrawal increased 5-HT(1A), 5-HT(2A) and 5-HT(2C) receptor mRNA. In imipramine-treated rats, E(2) (and E(2)-withdrawal) did not affect mRNA expression for any of the target genes. Thus, E(2) synergized behaviorally and neurochemically with an SSRI but not a tricyclic antidepressant.

  18. Possible role of resveratrol targeting estradiol and neprilysin pathways in lipopolysaccharide model of Alzheimer disease.

    PubMed

    El-Sayed, Nesrine S; Bayan, Yasmeen

    2015-01-01

    Alzheimer's disease (AD) is an irreversible, progressive neurodegenerative brain disease that slowly destroys memory and thinking skills. It is the most common cause of dementia among older people. One of the most important hallmarks of AD is the presence of amyloid beta (Aβ) peptide in the brain that suggests that it is the primary trigger for neuronal loss. Herbal extracts have been studied over the years for their potential therapeutic effect in AD. Resveratrol (RSV), one of the most important phytoestrogens, is considered to be useful as estrogen plays an important role in AD. One of the most important amyloid degrading enzymes is neprilysin (NEP), which plays a major role in degrading Aβ, and mainly affected by estrogen. So, the aim of the present study is investigating the possible role of resveratrol in lipopolysaccharide model of AD and the implication of its possible role in regulating the estradiol and neprilysin pathways. Mice were divided into four groups: Control group (0.9 % saline), LPS group (0.8 mg/kg i.p once), Treatment group with RSV (mice were once injected with LPS then after 30 min given a dose of {4 mg/kg} RSV for 7 days), and RSV group only (mice received 4 mg/kg i.p for 7 days only). After 7 days mice were subjected to different behavioral tests using Y-maze, object recognition test, and open field tests. Estradiol and NEP level were measured using ELISA kit. Results showed RSV was able to reverse the decline in different types of memory (working, nonspatial, and locomotor functions) caused by LPS induction in mice. Moreover RSV was able to significantly increase both the estradiol level and NEP level and that may have a great role to decrease Aβ deposition as it has been confirmed that there is a link between NEP and estradiol level; by upregulation of estradiol level this consequently leads to increase in the level of NEP level, and by increasing the NEP level in brain, this lead to decrease in Aβ deposition and enhancing its

  19. Dydrogesterone does not reverse the cardiovascular benefits of percutaneous estradiol.

    PubMed

    Kuba, V M; Teixeira, M A M; Meirelles, R M R; Assumpção, C R L; Costa, O S

    2013-02-01

    To evaluate the influence of dydrogesterone on estimated cardiovascular risk of users of hormone replacement therapy (HRT) (with percutaneous 17β-estradiol in monotherapy and in combination with dydrogesterone) and HRT non-users through the Framingham score tool for a period of 2 years. Framingham scores were calculated from the medical records of patients treated for at least 2 years with 17β-estradiol alone or in combination with dydrogesterone, along with HRT non-users, through the analysis of patient medical records, followed for at least 2 years at Instituto Estadual de Diabetes e Endocrinologia Luiz Capriglione. Improvements in lipid profile, glucose and blood pressure levels, which reduced the estimated cardiovascular risk, were observed in the 17β-estradiol group. Similar changes were observed in the users of 17β-estradiol + dydrogesterone, suggesting that this progestogen does not attenuate the effects caused by 17β-estradiol. Both HRT groups showed a reduction in their Framingham score. In contrast to data from other HRT investigations on cardiovascular risk, these formulations proved to be safe, even in the first year of use.

  20. Incidence of Venous Thromboembolism in Transgender Women Receiving Oral Estradiol.

    PubMed

    Arnold, Justin D; Sarkodie, Eleanor P; Coleman, Megan E; Goldstein, Deborah A

    2016-11-01

    One of the most serious known adverse effects of feminizing cross-sex hormone therapy (CSHT) is venous thromboembolism (VTE); however, no study has assessed the incidence of VTE from the hormone therapies used in the United States because previous publications on this topic have originated in Europe. CSHT in the United States typically includes estradiol with the antiandrogen spironolactone, whereas in Europe estradiol is prescribed with the progestin cyproterone acetate. To estimate the incidence of VTE from the standard feminizing CSHTs used in the United States. A retrospective chart review of transgender women who had been prescribed oral estradiol at a District of Columbia community health center was performed. The primary outcomes of interest were deep vein thrombosis or pulmonary emboli. From January 1, 2008 through March 31, 2016, 676 transgender women received oral estradiol-based CSHT for a total of 1,286 years of hormone treatment and a mean of 1.9 years of CSHT per patient. Only one individual, or 0.15% of the population, sustained a VTE, for an incidence of 7.8 events per 10,000 person-years. There was a low incidence of VTE in this population of transgender women receiving oral estradiol. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  1. The role of estradiol in male reproductive function

    PubMed Central

    Schulster, Michael; Bernie, Aaron M; Ramasamy, Ranjith

    2016-01-01

    Traditionally, testosterone and estrogen have been considered to be male and female sex hormones, respectively. However, estradiol, the predominant form of estrogen, also plays a critical role in male sexual function. Estradiol in men is essential for modulating libido, erectile function, and spermatogenesis. Estrogen receptors, as well as aromatase, the enzyme that converts testosterone to estrogen, are abundant in brain, penis, and testis, organs important for sexual function. In the brain, estradiol synthesis is increased in areas related to sexual arousal. In addition, in the penis, estrogen receptors are found throughout the corpus cavernosum with high concentration around neurovascular bundles. Low testosterone and elevated estrogen increase the incidence of erectile dysfunction independently of one another. In the testes, spermatogenesis is modulated at every level by estrogen, starting with the hypothalamus-pituitary-gonadal axis, followed by the Leydig, Sertoli, and germ cells, and finishing with the ductal epithelium, epididymis, and mature sperm. Regulation of testicular cells by estradiol shows both an inhibitory and a stimulatory influence, indicating an intricate symphony of dose-dependent and temporally sensitive modulation. Our goal in this review is to elucidate the overall contribution of estradiol to male sexual function by looking at the hormone's effects on erectile function, spermatogenesis, and libido. PMID:26908066

  2. Cellular mechanisms of estradiol-mediated masculinization of the brain.

    PubMed

    Schwarz, Jaclyn M; McCarthy, Margaret M

    2008-04-01

    The sexual differentiation of reproductive physiology and behavior in the rodent brain is largely determined by estradiol aromatized from testicular androgens. The cellular mechanisms by which estradiol masculinizes the brain are beginning to emerge and revealing novel features of brain development that are highly region-specific. In the preoptic area, the major site controlling male sexual behavior, estradiol increases the level of the COX-2 enzyme and its product, prostaglandin E2 which promotes dendritic spine synaptogenesis. In the ventromedial nucleus of the hypothalamus, the major site controlling female reproductive behavior, estradiol promotes glutamate release from synaptic terminals, activating NMDA receptors and the MAP kinase pathway. In the arcuate nucleus, a major regulator of anterior pituitary function, estradiol increases GABA synthesis, altering the morphology of neighboring astrocytes and reducing formation of dendritic spines synapses. Glutamate, GABA and the importance of neuronal-astrocytic cross-talk are emerging as common aspects of masculinization. Advances are also being made in the mechanistic basis of female brain development, although the challenges are far greater.

  3. The role of estradiol in male reproductive function.

    PubMed

    Schulster, Michael; Bernie, Aaron M; Ramasamy, Ranjith

    2016-01-01

    Traditionally, testosterone and estrogen have been considered to be male and female sex hormones, respectively. However, estradiol, the predominant form of estrogen, also plays a critical role in male sexual function. Estradiol in men is essential for modulating libido, erectile function, and spermatogenesis. Estrogen receptors, as well as aromatase, the enzyme that converts testosterone to estrogen, are abundant in brain, penis, and testis, organs important for sexual function. In the brain, estradiol synthesis is increased in areas related to sexual arousal. In addition, in the penis, estrogen receptors are found throughout the corpus cavernosum with high concentration around neurovascular bundles. Low testosterone and elevated estrogen increase the incidence of erectile dysfunction independently of one another. In the testes, spermatogenesis is modulated at every level by estrogen, starting with the hypothalamus-pituitary-gonadal axis, followed by the Leydig, Sertoli, and germ cells, and finishing with the ductal epithelium, epididymis, and mature sperm. Regulation of testicular cells by estradiol shows both an inhibitory and a stimulatory influence, indicating an intricate symphony of dose-dependent and temporally sensitive modulation. Our goal in this review is to elucidate the overall contribution of estradiol to male sexual function by looking at the hormone's effects on erectile function, spermatogenesis, and libido.

  4. Behavioral effects of electric and magnetic fields

    SciTech Connect

    Laties, V.G.

    1992-04-01

    Two set of behavioral studies were conducted. (1) Electric field: Three procedures were used to determine how aversive a 100 kV/m 60-Hz electric field is for the rat. Each of the procedures enabled rats to respond in order to reduce exposure to the field. The rats did reduce exposure slightly with one, but not with the other two, whereas they reduced their exposure to moderate illumination in all three procedures. The results show that while the procedures were appropriate for assessing stimulus aversiveness, 100 kV/m is not a generally aversive stimulus for the rat. (2) Magnetic Field: Thomas, Schrot and Liboff (Bioelectromagnetics: 7: 349--357 (1986)) reported that immediately after exposure for 30 min to a horizontal 60-Hz, 5 {times} 10{sup {minus}5}T field combined with a total static field of 2.61 {times} 10{sup {minus}5}T, the rate of lever pressing by rats increased during the DRL component of a multiple fixed ratio, DRL schedule of food reinforcement. This project failed to confirm those observations in an experiment that duplicated the behavioral baseline and the magnetic field exposure conditions, with the exception that the total DC vector was greater in these Rochester experiments than it was in Thomas et al, which was done in Bethesda, MD.

  5. Exercise testing in the evaluation of human responses to powerline frequency fields.

    PubMed

    Maresh, C M; Cook, M R; Cohen, H D; Graham, C; Gunn, W S

    1988-12-01

    The present study used exercise testing to examine the effects of 60-Hz electric and magnetic field exposure. Eleven males, 21-29 years, were tested during four experimental sessions (counterbalanced order and double-blind design). These included either 45-min exercise (50% of VO2 max) or no-exercise periods followed by either real field (9-kV/m, 16-A/m) or sham exposure for 2 h in a 60-Hz human exposure facility. Exercise produced a decrease in plasma volume and increases (p less than 0.05) in lactic acid, cortisol, growth hormone and testosterone levels, but these were not different under real and sham field conditions during the 2-h recovery periods. During no-exercise sessions, cardiac interbeat interval was increased (p less than 0.05), i.e., heart rate was slower, when subjects were exposed to real fields. Our results suggest that future studies should focus on evaluation of the effects of 60-Hz fields on the entire process of exercise-induced activation and recovery.

  6. Electric and magnetic fields and tumor progression. Final report

    SciTech Connect

    Keng, P.C.; Grota, L.J.; Michaelson, S.; Lu, S.T.

    1994-12-01

    This laboratory study has rigorously investigated two previously reported biological effects of 60-Hz electric and magnetic fields. The first effect involves nighttime suppression of melatonin synthesis in the pineal glands of rats exposed to high electric fields. The second concerns the increase in colony forming ability of human colon cancer cells exposed to 1.4-G magnetic fields. Neither effect was detected in the present study. A series of published laboratory studies on rats reported that 60-Hz electric fields at various field levels up to 130 kV/m suppress the nighttime synthesis of melatonin, a hormone produced by the pineal gland. Since melatonin is known to modulate the immune system and may inhibit cancer cell activity, changes in physiological levels of melatonin may have significant health consequences. In the repeat experiments, field exposure did not alter nighttime levels of melatonin or enzyme activities in the pineal gland. A small but statistically significant reduction of about 20% in serum melatonin was seen in exposed animals. Pineal melatonin was also unaffected by the presence of red light as a cofactor with field exposure or by time-shifting the daily field exposure period. Another study reported that 60-Hz magnetic fields can affect the colony forming ability of human cancer cells after exposure in a culture medium. In the repeat experiments, field exposure did not alter the colony forming ability of human Colo 205 cells in two different cell concentrations at plating or in two different incubation conditions. Field exposure also did not affect cell cycling in any of the four cell lines tested.

  7. β-Estradiol and ethinyl-estradiol contamination in the rivers of the Carpathian Basin.

    PubMed

    Avar, Péter; Zrínyi, Zita; Maász, Gábor; Takátsy, Anikó; Lovas, Sándor; G-Tóth, László; Pirger, Zsolt

    2016-06-01

    17β-Estradiol (E2) and 17α-ethinyl estradiol (EE2), which are environmental estrogens, have been determined with LC-MS in freshwater. Their sensitive analysis needs derivatization and therefore is very hard to achieve in multiresidue screening. We analyzed samples from all the large and some small rivers (River Danube, Drava, Mur, Sava, Tisza, and Zala) of the Carpathian Basin and from Lake Balaton. Freshwater was extracted on solid phase and derivatized using dansyl chloride. Separation was performed on a Kinetex XB-C18 column. Detection was achieved with a benchtop orbitrap mass spectrometer using targeted MS analysis for quantification. Limits of quantification were 0.05 ng/L (MS1) and 0.1 ng/L (MS/MS) for E2, and 0.001 ng/L (MS1) and 0.2 ng/L (MS/MS) for EE2. River samples contained n.d.-5.2 ng/L E2 and n.d.-0.68 ng/L EE2. Average levels of E2 and EE2 were 0.61 and 0.084 ng/L, respectively, in rivers, water courses, and Lake Balaton together, but not counting city canal water. EE2 was less abundant, but it was still present in almost all of the samples. In beach water samples from Lake Balaton, we measured 0.076-0.233 E2 and n.d.-0.133 EE2. A relative high amount of EE2 was found in river Zala (0.68 ng/L) and in Hévíz-Páhoki canal (0.52 ng/L), which are both in the catchment area of Lake Balaton (Hungary).

  8. Testosterone, estradiol, ACTH and musical, spatial and verbal performance.

    PubMed

    Hassler, M; Gupta, D; Wollmann, H

    1992-01-01

    Testosterone, estradiol, and ACTH were determined in blood serum of 26 healthy males aged 19.16 and of 25 healthy females aged 18.77 years on average, and results were correlated with test scores of three spatial tests, a verbal fluency measure, and a test measuring general musical ability. In addition, hemispheric lateralization for verbal material and handedness was assessed. While testosterone and estradiol alone were not significantly related to any of the cognitive or musical tests, testosterone/estradiol ratio was significantly negatively correlated with spatial tests, and ACTH was significantly positively correlated with spatial and musical tests. Correlations were stronger in females than in males. The laterality index was significantly negatively correlated with testosterone in males indicating that right hemisphere involvement in verbal processing was associated with high testosterone levels.

  9. Sympathetic regulation of estradiol secretion from the ovary.

    PubMed

    Uchida, Sae

    2015-01-01

    It is well known that hormone secretion from endocrine glands is regulated by hierarchical feedback mechanisms. However, although Cannon revealed in the 1920s that sympathoadrenal medullary function increased during emergency situations, no studies on the autonomic nervous regulation of hormone secretion have been undertaken for many years. In the past 40 years, the autonomic nervous regulation of insulin secretion from the pancreas, gastrin secretion from the stomach, glucocorticoid secretion from the adrenal cortex, etc., has been demonstrated. Estradiol secretion from the ovary is strongly controlled by the hypothalamic-pituitary-ovarian axis, and its possible regulation by autonomic nerves has been largely unnoticed. Some histological studies have revealed rich adrenergic sympathetic innervation in the ovary. Recently, it has been demonstrated that the activation of the sympathetic nerves to the ovary directly reduces estradiol secretion from the ovary. This article reviews physiological and morphological studies, primarily in rats, on the sympathetic regulation of estradiol secretion from the ovary.

  10. Macromolecular prodrugs. XIII. Hydrosoluble conjugates of 17β-estradiol and estradiol-17β-valerate with polyaspartamide polymer.

    PubMed

    Končič, Marijana Zovko; Zorc, Branka; Novak, Predrag

    2011-12-01

    Two hydrosoluble conjugates of 17β-estradiol (ED) and estradiol-17β-valerate (EV) with polyaspartamide polymer were prepared and characterized. ED and EV were first chemically modified and bound to poly[α,β-(N-2-hydroxyethyl-DL-aspartamide)]-poly[α,β-(N-2-aminoethyl-DL-aspartamide)] (PAHA), a hydrosoluble polyaspartamide-type copolymer bearing both hydroxyl and amino groups. ED was first converted to 17-hemisuccinate (EDS) and then bound to PAHA. In the resulting conjugate PAHA-EDS, the estradiol moiety was linked to the polymer through a 2-aminoethylhemisuccinamide spacer. On the other hand, EV was first converted to estradiol-17β-valerate-3-(benzotriazole-1-carboxylate), which readily reacted with amino groups in PAHA affording the polymer-drug conjugate PAHA-EV. In the prepared conjugate PAHA-EV, the estradiol moiety was covalently bound to the polyaspartamide backbone by carbamate linkage, through an ethylenediamine spacer. The polymer-drug conjugates were designed and prepared with the aim to increase water-solubility, bioavailability and to improve drug delivery of the lipophilic estrogen hormone.

  11. Estradiol modulates effort-based decision making in female rats.

    PubMed

    Uban, Kristina A; Rummel, Julia; Floresco, Stan B; Galea, Liisa A M

    2012-01-01

    Disorders of the dopamine system, such as schizophrenia or stimulant addiction, are associated with impairments in different forms of cost/benefit decision making. The neural circuitry (ie amygdala, prefrontal cortex, nucleus accumbens) underlying these functions receives dopamine input, which is thought to have a central role in mediating cost/benefit decisions. Estradiol modulates dopamine activity, and estrogen receptors (ERs) are found within this neurocircuitry, suggesting that decision making may be influenced by estradiol. The present study examined the contribution of estradiol and selective ERα and β agonists on cost/benefit decision making in adult female Long-Evans rats. An effort-discounting task was utilized, where rats could either emit a single response on a low-reward lever to receive two pellets, or make 2, 5, 10, or 20 responses on a high-reward lever to obtain four pellets. Ovariectomy increased the choice on the high-reward lever, whereas replacement with high (10 μg), but not low (0.3 μg), levels of estradiol benzoate reduced the choice on the high-reward lever. Interestingly, both an ERα agonist (propyl-pyrazole triol (PPT)) and an ERβ agonist (diarylpropionitrile (DPN)) increased choice on the high-reward lever when administered independently, but when these two agonists were combined, a decrease in choice for the high-reward lever was observed. The effects of estradiol, PPT, and DPN were more pronounced 24 h post-administration, suggesting that these effects may be genomic in nature. Together, these results demonstrate that estradiol modulates cost/benefit decision making in females, whereby concomitant activation of ERα and β receptors shifts the decision criteria and reduces preference for larger, yet more costly rewards.

  12. Estradiol Membrane-Initiated Signaling and Female Reproduction.

    PubMed

    Micevych, Paul E; Wong, Angela May; Mittelman-Smith, Melinda Anne

    2015-07-01

    The discoveries of rapid, membrane-initiated steroid actions and central nervous system steroidogenesis have changed our understanding of the neuroendocrinology of reproduction. Classical nuclear actions of estradiol and progesterone steroids affecting transcription are essential. However, with the discoveries of membrane-associated steroid receptors, it is becoming clear that estradiol and progesterone have neurotransmitter-like actions activating intracellular events. Ultimately, membrane-initiated actions can influence transcription. Estradiol membrane-initiated signaling (EMS) modulates female sexual receptivity and estrogen feedback regulating the luteinizing hormone (LH) surge. In the arcuate nucleus, EMS activates a lordosis-regulating circuit that extends to the medial preoptic nucleus and subsequently to the ventromedial nucleus (VMH)--the output from the limbic and hypothalamic regions. Here, we discuss how EMS leads to an active inhibition of lordosis behavior. To stimulate ovulation, EMS facilitates astrocyte synthesis of progesterone (neuroP) in the hypothalamus. Regulation of GnRH release driving the LH surge is dependent on estradiol-sensitive kisspeptin (Kiss1) expression in the rostral periventricular nucleus of the third ventricle (RP3V). NeuroP activation of the LH surge depends on Kiss1, but the specifics of signaling have not been well elucidated. RP3V Kiss1 neurons appear to integrate estradiol and progesterone information which feeds back onto GnRH neurons to stimulate the LH surge. In a second population of Kiss1 neurons, estradiol suppresses the surge but maintains tonic LH release, another critical component of the estrous cycle. Together, evidence suggests that regulation of reproduction involves membrane action of steroids, some of which are synthesized in the brain.

  13. Estradiol Membrane-Initiated Signaling and Female Reproduction

    PubMed Central

    Micevych, Paul E; Wong, Angela May; Mittelman-Smith, Melinda Anne

    2016-01-01

    The discoveries of rapid, membrane-initiated steroid actions and central nervous system steroidogenesis have changed our understanding of the neuroendocrinology of reproduction. Classical nuclear actions of estradiol and progesterone steroids affecting transcription are essential. However, with the discoveries of membrane-associated steroid receptors, it is becoming clear that estradiol and progesterone have neurotransmitter-like actions activating intracellular events. Ultimately, membrane-initiated actions can influence transcription. Estradiol membrane-initiated signaling (EMS) modulates female sexual receptivity and estrogen feedback regulating the luteinizing hormone (LH) surge. In the arcuate nucleus, EMS activates a lordosis-regulating circuit that extends to the medial preoptic nucleus and subsequently to the ventromedial nucleus (VMH)—the output from the limbic and hypothalamic regions. Here, we discuss how EMS leads to an active inhibition of lordosis behavior. To stimulate ovulation, EMS facilitates astrocyte synthesis of progesterone (neuroP) in the hypothalamus. Regulation of GnRH release driving the LH surge is dependent on estradiol-sensitive kisspeptin (Kiss1) expression in the rostral periventricular nucleus of the third ventricle (RP3V). NeuroP activation of the LH surge depends on Kiss1, but the specifics of signaling have not been well elucidated. RP3V Kiss1 neurons appear to integrate estradiol and progesterone information which feeds back onto GnRH neurons to stimulate the LH surge. In a second population of Kiss1 neurons, estradiol suppresses the surge but maintains tonic LH release, another critical component of the estrous cycle. Together, evidence suggests that regulation of reproduction involves membrane action of steroids, some of which are synthesized in the brain. PMID:26140715

  14. Extremely Low Frequency Vertical, 45-Hz Electric Field Exposure of Rats: A Search for Growth, Food, and Water Consumption, Blood Metabolite, Hematological, and Pathological Changes

    DTIC Science & Technology

    1977-06-01

    obtaining orientational and navigational information. 5 Other biological effects from ELF fields have been reported by Goodman et al. on Physarum ... polycephalum 3 and by Gavalas- Medici and Day-Magdaleno on monkeys. 2 Recently, large 60-Hz electric fields have been reported to reduce the growth of rats...Effects of ex- tremely low frequency el.;ctromagnetic fields on Physarum polyc. halum. Radiat. Res. 66:531-540, 1976. 4. Hollander, M. and Wolfe, D. A

  15. ESTRADIOL AND OSMOLALITY: BEHAVIORAL RESPONSES AND CENTRAL PATHWAYS

    PubMed Central

    Curtis, Kathleen S.

    2015-01-01

    Regulation of appropriate osmolality of body fluid is critical for survival, yet there are sex differences in compensatory responses to osmotic challenges. Few studies have focused on the role of sex hormones such as estradiol in behavioral responses to increases or decreases in systemic osmolality, and even fewer studies have investigated whether central actions of estrogens contribute to these responses. This overview integrates findings from a series of ongoing and completed experiments conducted in my laboratory to assess estradiol effects on water and NaCl intake in response to osmotic challenges, and on activity in central pathways that mediate such responses. PMID:26074202

  16. Estradiol and osmolality: Behavioral responses and central pathways.

    PubMed

    Curtis, Kathleen S

    2015-12-01

    Regulation of appropriate osmolality of body fluid is critical for survival, yet there are sex differences in compensatory responses to osmotic challenges. Few studies have focused on the role of sex hormones such as estradiol in behavioral responses to increases or decreases in systemic osmolality, and even fewer studies have investigated whether central actions of estrogens contribute to these responses. This overview integrates findings from a series of ongoing and completed experiments conducted in my laboratory to assess estradiol effects on water and NaCl intake in response to osmotic challenges, and on activity in central pathways that mediate such responses. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Animal studies on the role of 50/60-Hertz magnetic fields in carcinogenesis.

    PubMed

    Löscher, W; Mevissen, M

    1994-01-01

    A number of epidemiological studies have suggested that exposure to 50/60-Hz magnetic fields (MF) from power lines and electrical equipment may be associated with a modestly increased incidence of various types of cancer. Laboratory studies have indicated that nonionizing radiation has no mutagenic effect, i.e. does not initiate cancer. Thus, if 50/60-Hz MF are truly associated with an increased risk of cancer, then these fields must act as a promoter or co-promoter of cancer in cells that have already been initiated. This paper reviews the evidence produced by animal studies. As shown in this review, the available animal data on 50/60-Hz MF exposures seem to indicate that intermediate MF exposure exerts co-promoting effects in different tumor models, particularly cocarcinogenesis models of breast cancer, while chronic (up to life-time) exposure may exert promoting effects on "spontaneous" development of certain tumors. The tumor promoting or co-promoting effects of 50/60-Hz MF exposure found in several animal studies could relate to actions of MF on gene expression, immune surveillance, and Ca2+ homeostasis as demonstrated by in vitro experiments in cell cultures. However, the most plausible evidence for an in vivo effect of MF exposure which could be related to tumor promotion is reduction of circulating levels of melatonin, i.e. a hormone which is inhibitory to the growth of a wide range of cancers, particularly breast cancer. Animal studies have shown that 50-Hz MF exposure at flux densities as low as 0.3-1 mu Tesla significantly reduces nocturnal melatonin levels in plasma. While decrease of melatonin levels alone could explain tumor promoting or co-promoting effects of MF exposure, recent data indicate that MF exposure also impairs the effects of melatonin at the cellular level. Thus, the oncostatic effect of melatonin on cell proliferation of a human breast cancer cell line was antagonized by 60-Hz MF exposure at a flux density of about 1 mu Tesla. All these

  18. The effect of food on the bioavailability of norethindrone and ethinyl estradiol from norethindrone acetate/ethinyl estradiol tablets intended for continuous hormone replacement therapy.

    PubMed

    Boyd, Rebecca A; Zegarac, Elizabeth A; Eldon, Michael A

    2003-01-01

    As part of the development of a combination product containing norethindrone acetate and low-dose ethinyl estradiol for continuous hormone replacement therapy in postmenopausal women, a study was conducted to determine the effect of a high-fat meal on the bioavailability of norethindrone and ethinyl estradiol from tablets containing 1 mg norethindrone acetate/10 micrograms ethinyl estradiol. Eighteen healthy postmenopausal women participated in an open-label, single-dose, randomized, three-way crossover study in which 2 x 1/10 norethindrone acetate/ethinyl estradiol tablets were administered fasting and with a high-fat breakfast, and the same dose was administered in solution. Following each treatment, serial blood samples were collected for 48 hours, and plasma ethinyl estradiol and norethindrone concentrations were determined by a validated gas chromatography/mass spectrometry (GC/MS) method. Individual plasma ethinyl estradiol and norethindrone pharmacokinetic parameters were calculated by noncompartmental methods for each treatment and analyzed by ANOVA to obtain differences between least squares treatment mean values and associated 90% confidence intervals. Rates of ethinyl estradiol and norethindrone availability from tablets administered with food were slower than availability rates from tablets administered while fasting. Systemic exposure to ethinyl estradiol was unaffected by administration of tablets with food, whereas exposure to norethindrone increased by 27%. Because administration of norethindrone acetate/ethinyl estradiol 1/10 tablets with a high-fat meal did not decrease systemic exposure to norethindrone and ethinyl estradiol, this formulation can be taken without regard to meals.

  19. Endometriosis Under Estradiol Stimulation Imaged Using 18F-FDG and Its Control After Estradiol Cessation and Progesterone Hormonal Replacement.

    PubMed

    Arsenault, Frédéric; Turcotte, Éric

    2016-03-01

    Endometriosis is a frequent and benign cause of disabling abdominal pain, for which a diagnosis suspicion is clinically raised, but its confirmation necessitates a surgical exploration by laparoscopy. Foci of endometriosis proliferate under estrogen stimulation, like normal endometrium. We present a patient under estradiol stimulation for a history of endometrial cancer who underwent a PET/CT scan to assess an abdominal lesion showing a high F-FDG uptake, which normalized under progesterone hormonal replacement and cessation of estradiol. Two consecutive biopsies confirmed endometriosis. F-FDG evaluation of endometriosis under estrogen stimulation could be a promising approach to refractory endometriosis assessment.

  20. The Role of Hippocampal Estradiol Receptor-α in a Perimenopausal Affective Disorders-Like Rat Model and Attenuating of Anxiety by Electroacupuncture

    PubMed Central

    Huang, Yongheng; Ma, Shulan

    2016-01-01

    Hormone replacement therapy is the principal treatment for perimenopausal affective disorders which can cause severe side effects. The present study compared the effects of electroacupuncture (EA) and estradiol treatment on perimenopausal affective disorders at the behavioral and cellular levels. In this randomized experimental in vivo study, adult female rats were divided into intact, ovariectomy, chronic unpredictable stress (CUS), and ovariectomy and CUS combination groups. After week 6, all groups were subdivided to three subgroups of control, EA, and estradiol treatment. The behavioral parameters in the open field and the elevated plus maze tests were assessed before and after treatments. Alterations of serum steroid hormones and changes of estradiol receptor-α (ER-α) immunofluorescence neurons in the hippocampus sections were evaluated. EA treatment caused more antianxiety effects than estradiol treatment in CUS group (P < 0.05). Notably, estradiol and EA treatments had better significant behavioral effects when the models were not estrogen-deficient. Importantly, within each group, compared to the control group, the numbers of ER-α-positive neurons were significantly larger in EA subgroups. Therefore, EA had antianxiety effects on perimenopausal affective disorders caused by CUS but not by estrogen deficiency and upregulation of hippocampus ER-α neurons may contribute to its mechanism of action. PMID:28044085

  1. 9(10 leads to 19)abeo steriods. Total synthesis of abeo-estradiol, abeo-estradiol 3-methyl ether, and 17 alpha-ethynyl abeo-estradiol 3-methyl ether.

    PubMed

    Abushanab, E; Lee, D Y; Meresak, W A; Duax, W L

    1976-04-30

    Total synthesis of abeo-estradiol, abeo-estradiol 3-methyl ether, and 17alpha-ethynyl abeo-estradiol 3-methyl ether is described. Stereochemical assignments in 9(10 through 19) abeo-estradiol and its 3-methyl ether were made by X-ray analysis of the 17-keytone. Single crystals were grown by evaporation of a petroleum ether-ethanol solution and the intensities of 2619 diffraction spectra were measured, of which 1036 had intensity greater than twice the background. The structure was refined by full-matrix least-squares techniques and all hydrogen atoms were located in the Fourier difference syntheses.

  2. 21 CFR 862.1260 - Estradiol test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Estradiol test system. 862.1260 Section 862.1260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  3. [Systen--transdermal estradiol for substitution following surgical menopause].

    PubMed

    Rachev, E; Karag'ozov, I

    1995-01-01

    The authors investigate the clinical effect of transdermal system delivering 17 beta-estradiol for treatment of 23 patients after bilateral ovariectomy for benign genital tumors. During four to six months treatment Kuppermann index falls and karyopyknotic and maturation indices rise significantly. The side effects are extremely rare. The authors recommend the widely use of Systen for replacement therapy in surgically induced menopause.

  4. Fate of glucuronide conjugated estradiol in the environment

    USDA-ARS?s Scientific Manuscript database

    The fate and transport of conjugated reproductive hormones, which are polar compared to parent hormones, are little understood. Laboratory bench-scale soil (Hamar; Sandy, mixed, frigid typic Endoaquolls) sorption studies were conducted using [14C] 17ß-estradiol-3-glucuronide for a range of concentra...

  5. 21 CFR 862.1260 - Estradiol test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Estradiol test system. 862.1260 Section 862.1260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

  6. Fate of estradiol and testosterone in anaerobic lagoon digestors

    USDA-ARS?s Scientific Manuscript database

    Laboratory-scale lagoon digestors were constructed, and the fate of 14C-labelled 17ß-estradiol (E2) and testosterone (Test) were monitored for 42 d anaerobically under biological and sterile conditions. Hormone levels decreased in the liquid layer and increased in the sludge with time. At 42 d, 16-2...

  7. 21 CFR 862.1260 - Estradiol test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Estradiol test system. 862.1260 Section 862.1260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

  8. 21 CFR 862.1260 - Estradiol test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Estradiol test system. 862.1260 Section 862.1260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

  9. 21 CFR 862.1260 - Estradiol test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Estradiol test system. 862.1260 Section 862.1260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

  10. Fate of 17B-estradiol in anaerobic lagoon digesters

    USDA-ARS?s Scientific Manuscript database

    The fate of [14C]17B-estradiol ([14C]E2) was monitored for 42 d in triplicate 10 L anaerobic digesters. Total radioactive residues (TRR) decreased rapidly in the liquid layer of the digesters and reached a steady-state value of 19-24% of the initial dose after 4 days. LC/MS/MS analyses of the liqu...

  11. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ANIMAL DRUGS § 522.2478 Trenbolone acetate and estradiol benzoate. (a) Specifications. Each implant dose...) For an implant as described in paragraph (a)(1) of this section: (A) Amount. 200 mg trenbolone acetate... feed efficiency. (C) Limitations. Implant subcutaneously in ear only. Safety and effectiveness have not...

  12. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ANIMAL DRUGS § 522.2478 Trenbolone acetate and estradiol benzoate. (a) Specifications. Each implant dose...) For an implant as described in paragraph (a)(1) of this section: (A) Amount. 200 mg trenbolone acetate... feed efficiency. (C) Limitations. Implant subcutaneously in ear only. Safety and effectiveness have not...

  13. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ANIMAL DRUGS § 522.2478 Trenbolone acetate and estradiol benzoate. (a) Specifications. Each implant dose...) For an implant as described in paragraph (a)(1) of this section: (A) Amount. 200 mg trenbolone acetate... feed efficiency. (C) Limitations. Implant subcutaneously in ear only. Safety and effectiveness have not...

  14. Specificity Determinants of CYP1B1 Estradiol Hydroxylation

    PubMed Central

    Nishida, Clinton R.; Everett, Steven

    2013-01-01

    Cytochrome P450 (P450)-catalyzed oxidation of the aromatic ring of estradiol can result in 2- or 4-hydroxylation. Which of these products is formed is biologically important, as the 4-hydroxylated metabolite is carcinogenic, whereas the 2-hydroxylated metabolite is not. Most human P450 enzymes, including CYP1A1 and CYP1A2, exhibit a high preference for estradiol 2-hydroxylation, but human CYP1B1 greatly favors 4-hydroxylation. Here we show that heterologous expression of the human, monkey, dog, rat, and mouse CYP1B1 enzymes yields active proteins that differ in their estradiol hydroxylation specificity. The monkey and dog orthologs, like the human enzyme, preferentially catalyze 4-hydroxylation, but the rat and mouse enzymes favor 2-hydroxylation. Analysis of the CYP1B1 sequences in light of these findings suggested that one residue, Val395 in human CYP1B1, could account for the differential hydroxylation specificities. In fact, mutation of this valine in human CYP1B1 to the leucine present in the rat enzyme produces a human enzyme that has the 2-hydroxylation specificity of the rat enzyme. The converse is true when the leucine in the rat enzyme is mutated to the human valine. The role of CYP1B1 in estradiol carcinogenicity thus depends on the identity of this single amino acid residue. PMID:23821647

  15. Neurotensin enhances estradiol induced DNA synthesis in immature rat uterus

    SciTech Connect

    Mistry, A.; Vijayan, E.

    1985-05-27

    Systemic administration of Neurotensin, a tridecapeptide, in immature rats treated with estradiol benzoate significantly enhances uterine DNA synthesis as reflected by the incorporation of /sup 3/H-thymidine. The peptide may have a direct action on the uterus. Substance P, a related peptide, had no effect on uterine DNA synthesis. 18 references, 4 tables.

  16. 3D model of lamprey estrogen receptor with estradiol and 15alpha-hydroxy-estradiol.

    PubMed

    Baker, Michael E; Chang, David J; Chandsawangbhuwana, Charlie

    2009-06-25

    Lamprey, basal vertebrate, is an important model system for understanding early events in vertebrate evolution. Lamprey contains orthologs of the estrogen receptor [ER], progesterone receptor and corticoid receptor. A perplexing property of lamprey is that 15alpha-hydroxy-steroids are active steroids. For example, 15alpha-hydroxy-estradiol [15alpha-OH-E2] is the estrogen, instead of estradiol [E2]. To investigate how 15alpha-OH-E2 binds lamprey ER, we constructed a 3D model of the lamprey ER with E2 and 15alpha-OH-E2. We used the 3D structure of human ERalpha as a template to construct a 3D model of lamprey ER. E2 and 15alpha-OH-E2 were inserted into the 3D model of lamprey ER and 15alpha-OH-E2 was inserted into human ERalpha. Then the each steroid-protein complex was refined using Discover 3 from Insight II software. To determine if lamprey ER had some regions that were unique among vertebrate ERs, we used the ligand-binding domain of lamprey ER as a query for a BLAST search of GenBank. Our 3D model of lamprey ER with 15alpha-OH-E2 shows that Sdelta on Met-409 can form a hydrogen bond with the 15alpha-hydroxyl on 15alpha-OH-E2. In human ERalpha, the corresponding residue Ile-424 has a van der Waals contact with 15alpha-OH-E2. BLAST analysis of GenBank indicates that among vertebrate ERs, only lamprey ER contains a methionine at this position. Thus, the contact between Sdelta on Met-409 and 15alpha-OH-E2 is unique. Interestingly, BLAST finds that five New World monkeys and a sturgeon contain a valine instead of isoleucine. In addition to shedding light on the structure of the ER in a basal vertebrate, our 3D model of lamprey ER should prove useful in virtual screening of chemical libraries to identify compounds for controlling reproduction in sea lamprey, an environmental pest in Lake Michigan.

  17. 3D Model of Lamprey Estrogen Receptor with Estradiol and 15α-Hydroxy-Estradiol

    PubMed Central

    Baker, Michael E.; Chang, David J.; Chandsawangbhuwana, Charlie

    2009-01-01

    Background Lamprey, basal vertebrate, is an important model system for understanding early events in vertebrate evolution. Lamprey contains orthologs of the estrogen receptor [ER], progesterone receptor and corticoid receptor. A perplexing property of lamprey is that 15α-hydroxy-steroids are active steroids. For example, 15α-hydroxy-estradiol [15α-OH-E2] is the estrogen, instead of estradiol [E2]. To investigate how 15α-OH-E2 binds lamprey ER, we constructed a 3D model of the lamprey ER with E2 and 15α-OH-E2. Methodology We used the 3D structure of human ERα as a template to construct a 3D model of lamprey ER. E2 and 15α-OH-E2 were inserted into the 3D model of lamprey ER and 15α-OH-E2 was inserted into human ERα. Then the each steroid-protein complex was refined using Discover 3 from Insight II software. To determine if lamprey ER had some regions that were unique among vertebrate ERs, we used the ligand-binding domain of lamprey ER as a query for a BLAST search of GenBank. Principal Findings Our 3D model of lamprey ER with 15α-OH-E2 shows that Sδ on Met-409 can form a hydrogen bond with the 15α-hydroxyl on 15α-OH-E2. In human ERα, the corresponding residue Ile-424 has a van der Waals contact with 15α-OH-E2. BLAST analysis of GenBank indicates that among vertebrate ERs, only lamprey ER contains a methionine at this position. Thus, the contact between Sδ on Met-409 and 15α-OH-E2 is unique. Interestingly, BLAST finds that five New World monkeys and a sturgeon contain a valine instead of isoleucine. Significance In addition to shedding light on the structure of the ER in a basal vertebrate, our 3D model of lamprey ER should prove useful in virtual screening of chemical libraries to identify compounds for controlling reproduction in sea lamprey, an environmental pest in Lake Michigan. PMID:19557178

  18. Effect of moderate electric field frequency on growth kinetics and metabolic activity of Lactobacillus acidophilus.

    PubMed

    Loghavi, Laleh; Sastry, Sudhir K; Yousef, Ahmed E

    2008-01-01

    Moderate electric fields (MEF) have been previously shown to alter the metabolic activity of microbial cells; thus, the effect of frequency and electric field would be of considerable interest. We investigated herein the effects of MEF frequency on microbial growth kinetics and bacteriocin (Lacidin A) production of Lactobacillus acidophilus OSU 133 during fermentation. The following fermentation treatments were compared: conventional (for 40 h), MEF (1 V cm(-1), for 40 h), combination of MEF (1 V cm(-1), for the first 5 h) and conventional (for 35 h) at various frequency levels (45, 60, and 90 Hz) all at 30 degrees C, and control (conventional) fermentation at 37 degrees C. MEF treatments with purely sinusoidal waveforms at all frequencies at 30 degrees C produced a shorter lag phase than conventional fermentation. However, no lag phase reduction was found for a 60 Hz waveform that contained high-frequency harmonics. There was, however, a significant increase in the bacteriocin production under early MEF treatment at 60 Hz with high-frequency harmonics. On the basis of these observations, the fermentation process is accelerated by applying pure sinusoidal MEF at the early stage of growth while a significant increase in the bacteriocin production occurs when sinusoidal field at 60 Hz with harmonics is applied at the early stage of the growth.

  19. Vascular Effects of Early versus Late Postmenopausal Treatment with Estradiol.

    PubMed

    Hodis, Howard N; Mack, Wendy J; Henderson, Victor W; Shoupe, Donna; Budoff, Matthew J; Hwang-Levine, Juliana; Li, Yanjie; Feng, Mei; Dustin, Laurie; Kono, Naoko; Stanczyk, Frank Z; Selzer, Robert H; Azen, Stanley P

    2016-03-31

    Data suggest that estrogen-containing hormone therapy is associated with beneficial effects with regard to cardiovascular disease when the therapy is initiated temporally close to menopause but not when it is initiated later. However, the hypothesis that the cardiovascular effects of postmenopausal hormone therapy vary with the timing of therapy initiation (the hormone-timing hypothesis) has not been tested. A total of 643 healthy postmenopausal women were stratified according to time since menopause (<6 years [early postmenopause] or ≥10 years [late postmenopause]) and were randomly assigned to receive either oral 17β-estradiol (1 mg per day, plus progesterone [45 mg] vaginal gel administered sequentially [i.e., once daily for 10 days of each 30-day cycle] for women with a uterus) or placebo (plus sequential placebo vaginal gel for women with a uterus). The primary outcome was the rate of change in carotid-artery intima-media thickness (CIMT), which was measured every 6 months. Secondary outcomes included an assessment of coronary atherosclerosis by cardiac computed tomography (CT), which was performed when participants completed the randomly assigned regimen. After a median of 5 years, the effect of estradiol, with or without progesterone, on CIMT progression differed between the early and late postmenopause strata (P=0.007 for the interaction). Among women who were less than 6 years past menopause at the time of randomization, the mean CIMT increased by 0.0078 mm per year in the placebo group versus 0.0044 mm per year in the estradiol group (P=0.008). Among women who were 10 or more years past menopause at the time of randomization, the rates of CIMT progression in the placebo and estradiol groups were similar (0.0088 and 0.0100 mm per year, respectively; P=0.29). CT measures of coronary-artery calcium, total stenosis, and plaque did not differ significantly between the placebo group and the estradiol group in either postmenopause stratum. Oral estradiol

  20. Estimating systemic exposure to ethinyl estradiol from an oral contraceptive.

    PubMed

    Westhoff, Carolyn L; Pike, Malcolm C; Tang, Rosalind; DiNapoli, Marianne N; Sull, Monica; Cremers, Serge

    2015-05-01

    This study was conducted to compare single-dose pharmacokinetics of ethinyl estradiol in an oral contraceptive with steady-state values and to assess whether any simpler measures could provide an adequate proxy of the "gold standard" 24-hour steady-state area under the curve (AUC) value. Identification of a simple, less expensive measure of systemic ethinyl estradiol exposure would be useful for larger studies that are designed to assess the relationship between an individual's ethinyl estradiol exposure and side-effects. We collected 13 samples over 24 hours for pharmacokinetic analysis on days 1 and 21 of the first cycle of a monophasic oral contraceptive that contained 30 μg ethinyl estradiol and 150 μg levonorgestrel in 17 nonobese healthy white women. We also conducted an abbreviated single-dose 9-sample pharmacokinetic analysis after a month washout. Ethinyl estradiol was measured by liquid chromatography-tandem mass spectrometry. We compared results of a full 13-sample steady-state pharmacokinetic analysis with results that had been calculated with the use of fewer samples (9 or 5) and after the single doses. We calculated Pearson correlation coefficients to evaluate the relationships between these estimates of systemic ethinyl estradiol exposure. The AUC, maximum, and 24-hour values were similar after the 2 single oral contraceptive doses (AUC; r=0.92). The steady-state 13-sample 24-hour AUC value was correlated highly with the average 9-sample AUC value after the 2 single doses (r=0.81; P=.0002). This correlation remained the same if the number of single-dose samples was reduced to 4, taken at time 1, 2.5, 4, and 24 hours. The 24-hour value at steady-state was correlated highly with the 24-hour steady-state AUC value (r=0.92; P<.0001). The average of the 24-hour values after the 2 single doses was also correlated quite highly with the steady-state AUC value (r=0.72; P=.0026). Limited blood sampling, including results from 2 single doses, gave highly

  1. ESTIMATING SYSTEMIC EXPOSURE TO ETHINYL ESTRADIOL FROM AN ORAL CONTRACEPTIVE

    PubMed Central

    WESTHOFF, Carolyn L.; PIKE, Malcolm C.; TANG, Rosalind; DINAPOLI, Marianne N.; SULL, Monica; CREMERS, Serge

    2015-01-01

    Objectives This study was conducted to compare single-dose pharmacokinetics of ethinyl estradiol in an oral contraceptive to steady-state values, and to assess whether any simpler measures could provide an adequate proxy of the ‘gold standard’ 24-hour steady-state area-under-the-curve. Identifying a simple, less expensive, measure of systemic ethinyl estradiol exposure would be useful for larger studies designed to assess the relationship between an individual’s ethinyl estradiol exposure and her side effects. Study Design We conducted a 13 samples over 24 hours pharmacokinetic analysis on day 1 and day 21 of the first cycle of a monophasic oral contraceptive containing 30 mcg ethinyl estradiol and 150 mcg levonorgestrel in 17 non-obese healthy white women. We also conducted an abbreviated single dose 9-sample pharmacokinetic analysis after a month washout. Ethinyl estradiol was measured by liquid chromatography-tandem mass spectrometry. We compared results of full 13-sample steady-state pharmacokinetic analysis with results calculated using fewer samples (9 or 5) and following the single doses. We calculated Pearson correlation coefficients to evaluate the relationships between these estimates of systemic ethinyl estradiol exposure. Results The area-under-the-curve, maximum (Cmax), and 24-hour (C24) values were similar following the two single oral contraceptive doses (area-under-the-curve, r = 0.92). The steady-state 13-sample 24-hour area-under-the-curve was highly correlated with the average 9-sample area-under-the-curve after the two single doses (r = 0.81, p = 0.0002). This correlation remained the same if the number of samples was reduced to 4, taken at time 1, 2.5, 4 and 24 hours. The C24 at steady-state was highly correlated with the 24-hour steady-state area-under-the-curve (r = 0.92, p < 0.0001). The average of the C24 values following the two single doses was also quite highly correlated with the steady-state area-under-the-curve (r = 0.72, p = 0

  2. Pregnancy-Induced Gingivitis and OMICS in Dentistry: In Silico Modeling and in Vivo Prospective Validation of Estradiol-Modulated Inflammatory Biomarkers

    PubMed Central

    Zeidán-Chuliá, Fares; Könönen, Eija; Moreira, José C. F.; Liukkonen, Joonas; Sorsa, Timo; Gürsoy, Ulvi K.

    2014-01-01

    Abstract Pregnancy-associated gingivitis is a bacterial-induced inflammatory disease with a remarkably high prevalence ranging from 35% to 100% across studies. Yet little is known about the attendant mechanisms or diagnostic biomarkers that can help predict individual susceptibility for rational personalized medicine. We aimed to define inflammatory proteins in saliva, induced or inhibited by estradiol, as early diagnostic biomarkers or target proteins in relation to pregnancy-associated gingivitis. An in silico gene/protein interaction network model was developed by using the STITCH 3.1 with “experiments” and “databases” as input options and a confidence score of 0.700 (high confidence). Salivary estradiol, interleukin (IL)-1β and -8, myeloperoxidase (MPO), matrix metalloproteinase (MMP)-2, -8, and -9, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 levels from 30 women were measured prospectively three times during pregnancy and twice during postpartum. In silico analysis revealed that estradiol interacts with IL-1β and -8 by an activation link when the “actions view” was consulted. In saliva, estradiol concentrations associated positively with TIMP-1 and negatively with MPO and MMP-8 concentrations. When the gingival bleeding on probing percentage (BOP%) was included in the model as an effect modifier, the only association, a negative one, was found between estradiol and MMP-8. Throughout gestation, estradiol modulates the inflammatory response by inhibiting neutrophilic enzymes, such as MMP-8. The interactions between salivary degradative enzymes and proinflammatory cytokines during pregnancy suggest promising ways to identify candidate biomarkers for pregnancy-associated gingivitis, and for personalized medicine in the field of dentistry. Finally, we call for greater investments in, and action for biomarker research in periodontology and dentistry that have surprisingly lagged behind in personalized medicine compared to other fields

  3. Pregnancy-induced gingivitis and OMICS in dentistry: in silico modeling and in vivo prospective validation of estradiol-modulated inflammatory biomarkers.

    PubMed

    Gürsoy, Mervi; Zeidán-Chuliá, Fares; Könönen, Eija; Moreira, José C F; Liukkonen, Joonas; Sorsa, Timo; Gürsoy, Ulvi K

    2014-09-01

    Pregnancy-associated gingivitis is a bacterial-induced inflammatory disease with a remarkably high prevalence ranging from 35% to 100% across studies. Yet little is known about the attendant mechanisms or diagnostic biomarkers that can help predict individual susceptibility for rational personalized medicine. We aimed to define inflammatory proteins in saliva, induced or inhibited by estradiol, as early diagnostic biomarkers or target proteins in relation to pregnancy-associated gingivitis. An in silico gene/protein interaction network model was developed by using the STITCH 3.1 with "experiments" and "databases" as input options and a confidence score of 0.700 (high confidence). Salivary estradiol, interleukin (IL)-1β and -8, myeloperoxidase (MPO), matrix metalloproteinase (MMP)-2, -8, and -9, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 levels from 30 women were measured prospectively three times during pregnancy and twice during postpartum. In silico analysis revealed that estradiol interacts with IL-1β and -8 by an activation link when the "actions view" was consulted. In saliva, estradiol concentrations associated positively with TIMP-1 and negatively with MPO and MMP-8 concentrations. When the gingival bleeding on probing percentage (BOP%) was included in the model as an effect modifier, the only association, a negative one, was found between estradiol and MMP-8. Throughout gestation, estradiol modulates the inflammatory response by inhibiting neutrophilic enzymes, such as MMP-8. The interactions between salivary degradative enzymes and proinflammatory cytokines during pregnancy suggest promising ways to identify candidate biomarkers for pregnancy-associated gingivitis, and for personalized medicine in the field of dentistry. Finally, we call for greater investments in, and action for biomarker research in periodontology and dentistry that have surprisingly lagged behind in personalized medicine compared to other fields, such as cancer research.

  4. Oral contraceptives and cognition: A role for ethinyl estradiol.

    PubMed

    Beltz, Adriene M; Hampson, Elizabeth; Berenbaum, Sheri A

    2015-08-01

    This article is part of a Special Issue "Estradiol and cognition". Estrogens have been seen to play a role in human cognitive abilities, but questions remain about the cognitive impact of ethinyl estradiol, which is contained in many oral contraceptives (OCs). Inconsistencies in past studies likely reflect small samples and heterogeneous groups of OC users. The aims of the present work were to examine OC effects on sex-typed spatial and verbal abilities by (a) comparing mental rotations and expressional fluency in normally-cycling (NC) women and men to OC users considered as a heterogeneous group and then to homogeneous groups of OC users created by classifying pills according to their active constituents, and (b) determining the relation between synthetic hormone doses in OCs and mental rotations and expressional fluency. Participants were 136 men, 93 NC women, and 148 OC users, including homogeneous monophasic (n = 55) and triphasic (n = 43) OC groups, aged 18 to 30 years. Significant effects of OC use were seen in homogeneous group comparisons but not when OC users were considered as a heterogeneous group. On mental rotations, men outperformed women, and monophasic OC users outperformed NC women. The latter difference may be attributable to estradiol, as ethinyl estradiol was inversely related to spatial ability among OC users and was lower in monophasic than in triphasic users. On expressional fluency, NC women and monophasic OC users outperformed men, and monophasic users outperformed triphasic users. Thus, results show the importance of ethinyl estradiol and of considering pill constituents when studying the cognitive effects of OCs.

  5. Catalase and estradiol inhibit mitochondrial protein S-glutathionylation.

    PubMed

    Hu, Bin; Allina, Jorge; Bai, Jingxiang; Kesar, Vivek; Odin, Joseph A

    2012-08-01

    Regulation and downstream effects of mitochondrial protein S-glutathionylation in response to oxidative stress are poorly understood. The study aim was to determine whether anti-oxidants such as catalase and estradiol alter mitochondrial protein S-glutathionylation and in turn affect apoptosis following ultraviolet B (UV-B) light irradiation. HeLa cells were transduced with increasing amounts of adenovirus encoding catalase (Ad-Cat) and β-galactosidase (Ad-Lac Z) or pre-incubated with estradiol before induction of apoptosis by UV-B light exposure. Inhibition of mitochondrial protein S-glutathionylation was assessed using autoantibodies specific for the non-S-glutathionylated form of PDC-E2. The percentage of apoptotic cells following UV-B irradiation were not significantly different between mock cells (cells with no virus infection) and Ad-Cat and Ad-Lac Z infected cells at all viral doses (all p > 0.050). Autoantibody staining of non-S-glutathionylated PDC-E2 in apoptotic cells was three times greater in only Ad-Cat infected cells compared to only Ad-Lac Z infected cells (81.3 ± 16.7 vs 26 ± 7.2 %, respectively, p = 0.030). Similarly estradiol treatment (33 and 100 nM) also significantly increased PDC-E2 staining in apoptotic cells compared to non-treated cells (both p < 0.010). The percentage of apoptotic cells was not significantly different with any of the estradiol concentrations (all p > 0.100). The observed procaspase 12 cleavage following UV-B irradiation suggests that a mitochondrial-independent apoptotic pathway was activated. In conclusion, following an apoptotic stimulus, estradiol may inhibit mitochondrial protein S-glutathionylation without inhibiting apoptosis. This effect may play a role in ninefold greater prevalence of autoantibodies against PDC-E2 in women with primary biliary cirrhosis.

  6. The Stimulation of HSD17B7 Expression by Estradiol Provides a Powerful Feed-Forward Mechanism for Estradiol Biosynthesis in Breast Cancer Cells

    PubMed Central

    Shehu, Aurora; Albarracin, Constance; Devi, Y. Sangeeta; Luther, Kristin; Halperin, Julia; Le, Jamie; Mao, Jifang; Duan, Rachel W.; Frasor, Jonna

    2011-01-01

    Our laboratory has previously cloned and purified an ovarian protein found to be a novel 17β-hydroxysteroid dehydrogenase type 7 enzyme (HSD17B7) (formerly prolactin receptor-associated protein) that converts the weak estrogen, estrone, to the highly potent estradiol. The regulation of this enzyme has not yet been explored. In this report, we show high expression of HSD17B7 in human ductal carcinoma and breast cancer cell lines and present evidence for a strong up-regulation of this enzyme by estradiol at the level of mRNA, protein expression, and promoter activity in MCF-7 cells. The effect of estradiol is mediated by estrogen receptor (ER)α, whereas ERβ prevents this stimulation. ER antagonists, ICI 182,780 and 4-hydroxytamoxifen, prevent estradiol-induced stimulation of the endogenously expressed HSD17B7, suggesting that these inhibitors not only block estradiol action but also its production. We have identified a −185-bp region of the hsd17b7 promoter that is highly conserved among rat, mouse, and human and confers regulation by estradiol in MCF-7 cells. This region is devoid of a classical estradiol-response element but contains a nuclear factor 1 (NF1) site that is essential for estradiol action. We found that estradiol stimulates the recruitment and DNA binding of NF1 to this region of the hsd17b7 promoter. Furthermore, knockdown of NF1 family members, NF1B, NF1A, and NF1X, completely prevents induction of this gene by estradiol. In summary, our findings demonstrate that estradiol stimulates HSD17B7 transcriptional activity in breast cancer cells through a novel mechanism requiring NF1 and strongly suggest a positive feedback mechanism to increase local estradiol synthesis causing growth of estrogen-dependent breast cancers. PMID:21372145

  7. ESTRADIOL AND THE ESTRADIOL METABOLITE, 2-HYDROXYESTRADIOL, ACTIVATE AMP-ACTIVATED PROTEIN KINASE IN C2C12 MYOTUBES

    USDA-ARS?s Scientific Manuscript database

    Systemic loss of estradiol (E2) during menopause is associated with increased adiposity which can be prevented with E2 replacement. Rodent studies suggest that E2, or lack of, is a key mediator in menopause-related metabolic changes. We have previously demonstrated that E2 treatment produces a rap...

  8. Proportionality of ELF electric field-induced growth inhibition to induced membrane potential in Zea mays and Vicia faba roots.

    PubMed

    Brayman, A A; Megumi, T; Miller, M W

    1990-01-01

    The postulate that 60-Hz electric field-induced bioeffect severity is proportional to induced transmembrane potential [Vmi] magnitude was tested and supported using a plant root model cell system. Statistically significant correlations were obtained upon regression of the relative rates of exposed Vicia faba and Zea mays root segment growth on the average Vmi (calculated) arising in those segments under specified 60 Hz field exposure conditions. The Vmi associated with the apparent threshold for growth inhibition was similar in Zea and Vicia roots (2.5 vs 2.4 mV, respectively). At Vmi greater than this threshold, Zea root growth declined by about 9% per mV, and Vicia root growth by about 19% per mV induced potential.

  9. Estradiol-dependent modulation of auditory processing and selectivity in songbirds

    PubMed Central

    Maney, Donna; Pinaud, Raphael

    2011-01-01

    The steroid hormone estradiol plays an important role in reproductive development and behavior and modulates a wide array of physiological and cognitive processes. Recently, reports from several research groups have converged to show that estradiol also powerfully modulates sensory processing, specifically, the physiology of central auditory circuits in songbirds. These investigators have discovered that (1) behaviorally-relevant auditory experience rapidly increases estradiol levels in the auditory forebrain; (2) estradiol instantaneously enhances the responsiveness and coding efficiency of auditory neurons; (3) these changes are mediated by a non-genomic effect of brain-generated estradiol on the strength of inhibitory neurotransmission; and (4) estradiol regulates biochemical cascades that induce the expression of genes involved in synaptic plasticity. Together, these findings have established estradiol as a central regulator of auditory function and intensified the need to consider brain-based mechanisms, in addition to peripheral organ dysfunction, in hearing pathologies associated with estrogen deficiency. PMID:21146556

  10. Estradiol reduces dendritic spine density in the ventral striatum of female Syrian hamsters.

    PubMed

    Staffend, Nancy A; Loftus, Caroline M; Meisel, Robert L

    2011-01-01

    Estradiol affects a variety of brain regions by modulating physiological and cellular functions as well as neuronal morphology. Within the striatum, estradiol is known to induce physiological and molecular changes, yet estradiol's effects on striatal dendritic morphology have not yet been evaluated. Using ballistic delivery of the lipophilic dye DiI to tissue sections, we were able to evaluate estradiol's effects on striatal morphology in female Syrian hamsters. We found that estradiol significantly decreased spine density within the nucleus accumbens core, with no effect in the nucleus accumbens shell or caudate. Interestingly, estradiol treatment caused a significant deconstruction of spines from more to less mature spine subtypes in both the nucleus accumbens core and shell regardless of changes in spine density. These results are significant in that they offer a novel mechanism for estradiol actions on a wide variety of nucleus accumbens functions such as motivation or reward as well as their pathological consequences (e.g. drug addiction).

  11. ELF magnetic fields increase amino acid uptake into Vicia faba L. roots and alter ion movement across the plasma membrane.

    PubMed

    Stange, B C; Rowland, R E; Rapley, B I; Podd, J V

    2002-07-01

    Vicia faba seedlings, subjected to a 10 microT 50 Hz square wave magnetic field for 40 min together with a radioactive pulse, showed a marked increase in amino acid uptake into intact roots. A more modest increase was observed with a 100 microT 50 Hz square wave. An increase in media conductivity at low field intensities from 10 microT 50 Hz square wave, 100 microT 50 Hz sine wave, and 100 microT 60 Hz square wave fields, indicated an alteration in the movement of ions across the plasma membrane, most likely due to an increase in net outflow of ions from the root cells. Similarly, marked elevation in media pH, indicating increased alkalinity, was observed at 10 and 100 microT for both square and sine waves at both 50 and 60 Hz. Our data would indicate that low magnetic field intensities of 10 and 100 microT at 50 or 60 Hz can alter membrane transport processes in root tips. Copyright 2002 Wiley-Liss, Inc.

  12. Relationship between ovarian reserve and preovulatory estradiol during a fixed-time AI protocol in beef heifers

    USDA-ARS?s Scientific Manuscript database

    Estradiol production is essential for reproductive efficiency. This study compared numbers of follicles in beef cows that did or did not have elevated preovulatory estradiol during a fixed-time AI (FTAI) protocol. In experiment 1, 5 low estradiol (LowE2) and 5 high estradiol (HighE2) cows were slaug...

  13. Estimation of estradiol in mouse serum samples: evaluation of commercial estradiol immunoassays.

    PubMed

    Haisenleder, Daniel J; Schoenfelder, Aleisha H; Marcinko, Elizabeth S; Geddis, Lisa M; Marshall, John C

    2011-11-01

    The University of Virginia Center for Research in Reproduction Ligand Core performed an evaluation of nine commercial estradiol (E2) immunoassays for use with mouse serum. The evaluation had two components. 1) Recovery Studies: a mouse pool was spiked with E2 concentrations across the assay range, and percent recovery and parallelism to the assay standard curve were determined. 2) Correlation Studies: serum pools were collected from intact females, ovariectomized (OVX) and OVX-E2 treated mice and E2 assayed, then measured by gas chromatography/tandem mass spectrometry (GC/MSMS) for comparison to a gold standard method. Recovery results showed that E2 recovery from spiked mouse pools varied greatly (from <18% to >640%) among kits tested. However, three kits (DiaSorin Radioimmunoassay, Siemens Double Antibody RIA, and CalBiotech Enzyme Immunoassay) showed reasonable recoveries and parallelism. Data collected from the Correlation Study showed that values from intact, OVX and OVX-E2-treated mouse pools varied by several fold vs. GC/MSMS for most of the kits tested. The DiaSorin RIA and CalBiotech Enzyme Immunoassay Kits showed the best correlation to GC/MSMS. Unfortunately, while this evaluation was ongoing, the DiaSorin Kit was discontinued. In summary, the CalBiotech Kit was the only available assay tested that demonstrated good E2 parallelism to the assay standard curve and accuracy vs. a gold standard method (i.e. GC/MSMS). Also of note, the CalBiotech assay is sensitive and requires minimal sample volume. Therefore, based on these findings the CalBiotech E2 assay has been implemented for use in mouse serum samples within the Ligand Core.

  14. Estimation of Estradiol in Mouse Serum Samples: Evaluation of Commercial Estradiol Immunoassays

    PubMed Central

    Schoenfelder, Aleisha H.; Marcinko, Elizabeth S.; Geddis, Lisa M.; Marshall, John C.

    2011-01-01

    The University of Virginia Center for Research in Reproduction Ligand Core performed an evaluation of nine commercial estradiol (E2) immunoassays for use with mouse serum. The evaluation had two components. 1) Recovery Studies: a mouse pool was spiked with E2 concentrations across the assay range, and percent recovery and parallelism to the assay standard curve were determined. 2) Correlation Studies: serum pools were collected from intact females, ovariectomized (OVX) and OVX-E2 treated mice and E2 assayed, then measured by gas chromatography/tandem mass spectrometry (GC/MSMS) for comparison to a gold standard method. Recovery results showed that E2 recovery from spiked mouse pools varied greatly (from <18% to >640%) among kits tested. However, three kits (DiaSorin Radioimmunoassay, Siemens Double Antibody RIA, and CalBiotech Enzyme Immunoassay) showed reasonable recoveries and parallelism. Data collected from the Correlation Study showed that values from intact, OVX and OVX-E2-treated mouse pools varied by several fold vs. GC/MSMS for most of the kits tested. The DiaSorin RIA and CalBiotech Enzyme Immunoassay Kits showed the best correlation to GC/MSMS. Unfortunately, while this evaluation was ongoing, the DiaSorin Kit was discontinued. In summary, the CalBiotech Kit was the only available assay tested that demonstrated good E2 parallelism to the assay standard curve and accuracy vs. a gold standard method (i.e. GC/MSMS). Also of note, the CalBiotech assay is sensitive and requires minimal sample volume. Therefore, based on these findings the CalBiotech E2 assay has been implemented for use in mouse serum samples within the Ligand Core. PMID:21933867

  15. [Metabolism of lipoproteins in rats treated with ethinyl estradiol].

    PubMed

    Tvorogova, M G; Titov, V N

    1986-01-01

    Effect of ethinyl-estradiol on metabolism of lipoproteins was studied in rat blood. Administration of ethinyl-estradiol at a dose of 50 micrograms/kg of body mass led to hypocholesterolemia and to hypertriglyceridemia in blood of experimental animals as well as the hormone impaired lipid composition of all the lipoprotein classes. These alterations in lipid composition of lipoproteins occurred as a result of an increase in biosynthesis and secretion of very low density lipoproteins as well as due to impairments of lipoprotein transformation in blood serum caused by a decrease in activity of main enzymes responsible for the transformation of lipoproteins in circulation--lipoprotein lipase, liver triglyceride lipase and lecithin-cholesterol acyltransferase.

  16. Estradiol Upregulates c-FLIPlong Expression in Anterior Pituitary Cells.

    PubMed

    Jaita, G; Zárate, S; Ferraris, J; Gottardo, M F; Eijo, G; Magri, M L; Pisera, D; Seilicovich, A

    2016-04-01

    Anterior pituitary cell turnover depends on a tight balance between proliferation and apoptosis. We have previously shown that estrogens sensitize anterior pituitary cells to pro-apoptotic stimuli. c-FLIP (cellular-FLICE-inhibitory-protein) isoforms are regulatory proteins of apoptosis triggered by death receptors. c-FLIPshort isoform competes with procaspase-8 inhibiting its activation. However, c-FLIPlong isoform may have a pro- or anti-apoptotic function depending on its expression level. In the present study, we explored whether estrogens modulate c-FLIP expression in anterior pituitary cells from ovariectomized (OVX) rats and in GH3 cells, a somatolactotrope cell line. Acute administration of 17β-estradiol to OVX rats increased c-FLIPlong expression in the anterior pituitary gland without changing c-FLIPshort expression as assessed by Western blot. Estradiol in vitro also increased c-FLIPlong expression in anterior pituitary cells but not in GH3 cells. As determined by flow cytometry, the percentage of anterior pituitary cells expressing c-FLIP was higher than in GH3 cells. However, c-FLIP fluorescence intensity in GH3 cells was higher than in anterior pituitary cells. FasL increased the percentage of TUNEL-positive GH3 cells incubated either with or without estradiol suggesting that the pro-apoptotic action of Fas activation is estrogen-independent. Our results show that unlike what happens in nontumoral pituitary cells, estrogens do not modulate either c-FLIPlong expression or FasL-induced apoptosis in GH3 cells. The stimulatory effect of estradiol on c-FLIPlong expression could be involved in the sensitizing effect of this steroid to apoptosis in anterior pituitary cells. The absence of this estrogenic action in tumor pituitary cells could be involved in their tumor-like behavior.

  17. High-performance liquid chromatographic determination of 17beta-estradiol and 17beta-estradiol-3-acetate solubilities and diffusion coefficents in silicone elastromeric intravaginal rings.

    PubMed

    Russell, J A; Malcolm, R K; Campbell, K; Woolfson, A D

    2000-07-07

    A rapid, sensitive reversed-phase high-performance liquid chromatographic method has been developed for the determination of in vitro release of 17beta-estradiol and its ester prodrug, 17beta-estradiol-3-acetate, from silicone intravaginal rings. Partial hydrolysis of the acetate under the aqueous conditions provided by the 1% benzalkonium chloride release medium necessitates its conversion to 17beta-estradiol prior to HPLC analysis. Both steroid peaks have been fully resolved from the benzalkonium chloride peaks by the reported chromatographic method, which employs a C18 bonded reversed-phase column, an acetonitrile-water (50:50, v/v) mobile phase and a UV detection wavelength of 281 nm. The peak area versus 17beta-estradiol concentration was found to be linear over the range of 0.0137-1347 microkg ml(-1). The HPLC method has also been used to determine the silicone solubilities and diffusion coefficients of the two related steroids. The almost 100-fold increase in 17beta-estradiol-3-acetate release from the silicone core-type intravaginal rings compared to 17beta-estradiol is shown to be due to a 60-fold increase in silicone solubility and a one and a half-fold increase in diffusitivity. The results demonstrate that an effective estrogen replacement therapy dose of 17beta-estradiol may be administered from a silicone intravaginal reservoir device containing the labile 17beta-estradiol-3-acetate prodrug.

  18. Actions and interactions of estradiol and glucocorticoids in cognition and the brain: Implications for aging women.

    PubMed Central

    Herrera, Alexandra Ycaza; Mather, Mara

    2015-01-01

    Menopause involves dramatic declines in estradiol production and levels. Importantly, estradiol and the class of stress hormones known as glucocorticoids exert countervailing effects throughout the body, with estradiol exerting positive effects on the brain and cognition, glucocorticoids exerting negative effects on the brain and cognition, and estradiol able to mitigate negative effects of glucocorticoids. Although the effects of these hormones in isolation have been extensively studied, the effects of estradiol on the stress response and the neuroprotection offered against glucocorticoid exposure in humans are less well known. Here we review evidence suggesting that estradiol-related protection against glucocorticoids mitigates stress-induced interference with cognitive processes. Animal and human research indicates that estradiol-related mitigation of glucocorticoid damage and interference is one benefit of estradiol supplementation during peri-menopause or soon after menopause. The evidence for estradiol-related protection against glucocorticoids suggests that maintaining estradiol levels in post-menopausal women could protect them from stress-induced declines in neural and cognitive integrity. PMID:25929443

  19. Estradiol and cortisol interactions in youth externalizing psychopathology.

    PubMed

    Tackett, Jennifer L; Reardon, Kathleen W; Herzhoff, Kathrin; Page-Gould, Elizabeth; Harden, K Paige; Josephs, Robert A

    2015-05-01

    Growing evidence has indicated that gonadal and stress hormones interact to shape socially dominant behavior and externalizing psychopathology; however, such work to date has focused exclusively on the testosterone-cortisol interaction, despite expectations that estradiol should be associated with similar behavioral outcomes to testosterone. Here, we present the first empirical test of the hypothesis that adolescent males and females (N=105, ages 13-18) with high estradiol and low cortisol concentrations are at highest risk for externalizing problems, but - replicating previous work - only among adolescents high on pathological personality traits. Parents reported on youth psychopathology and personality, and hormone concentrations were measured via passive drool. Results confirmed the hypothesis: high estradiol was associated with more externalizing behaviors, but only when cortisol was low and personality traits of disagreeableness and emotional instability were high. Further, these associations held when controlling for testosterone concentrations. These findings provide the first empirical evidence of a hypothalamic pituitary adrenal (HPA)×hypothalamic pituitary gonadal (HPG) axis interaction that extends the "dual hormone" hypothesis beyond testosterone. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Actions of estradiol on discrete attributes of the luteinizing hormone pulse signal in man. Studies in postmenopausal women treated with pure estradiol.

    PubMed Central

    Veldhuis, J D; Evans, W S; Rogol, A D; Thorner, M O; Stumpf, P

    1987-01-01

    We assessed the time-dependent impact of estradiol on properties of the luteinizing hormone (LH) pulse signal in 12 hypoestrogenemic postmenopausal volunteers studied basally and after 1, 5, 10, and 30 d of estradiol delivery via an intravaginal Silastic ring. Computerized analysis of the plasma LH time series revealed a significant decrease in LH pulse frequency within 24 h of estrogen treatment, followed by a secondary increase (days 5 and 10), and then a sustained decline (day 30) in LH pulsatility. Estradiol also significantly suppressed incremental and maximal (but not fractional) LH pulse amplitudes in a biphasic manner. In contrast, LH peak duration was invariant until day 30 of estradiol replacement. These observations indicate that the well recognized biphasic actions of estradiol on mean serum LH concentrations can be modeled in relation to specific and time-dependent alterations in LH pulse frequency and amplitude. PMID:3818948

  1. The effects of 17beta estradiol, 17alpha estradiol and progesterone on oxidative stress biomarkers in ovariectomized female rat brain subjected to global cerebral ischemia.

    PubMed

    Ozacmak, V H; Sayan, H

    2009-01-01

    Neuroprotective effects of estrogens and progesterone have been widely studied in various experimental models. The present study was designed to compare possible neuroprotective effects of 17alpha-estradiol, 17beta-estradiol, and progesterone on oxidative stress in rats subjected to global cerebral ischemia. Global cerebral ischemia was induced in ovariectomized female rats by four vessel occlusion for 10 min. Following 72 h of reperfusion, levels of malondialdehyde (MDA, oxidative stress marker), and reduced glutathione (GSH, major endogenous antioxidant) were assessed in hippocampus, striatum and cortex of rats treated with either 17alpha-estradiol, 17beta-estradiol, progesterone or estradiol + progesterone beforehand. Steroid administration ameliorated ischemia-induced decrease in GSH and increase in MDA levels. Our data offers additional evidence that estrogens and progesterone or combination of two exert a remarkable neuroprotective effect reducing oxidative stress.

  2. Hemostatic effects of a novel estradiol-based oral contraceptive: an open-label, randomized, crossover study of estradiol valerate/dienogest versus ethinylestradiol/levonorgestrel.

    PubMed

    Klipping, Christine; Duijkers, Ingrid; Parke, Susanne; Mellinger, Uwe; Serrani, Marco; Junge, Wolfgang

    2011-01-01

    A novel estradiol-based combined oral contraceptive (COC) is currently available in many countries worldwide, including Europe and the US. Based on previous studies, it is expected that this estradiol-based COC will have a reduced hepatic effect compared with COCs containing ethinylestradiol with regard to proteins controlling the hemostatic balance. The aim of this study was to compare the hemostatic effects of the estradiol valerate/dienogest COC with a monophasic low-estrogen dose COC containing ethinylestradiol/levonorgestrel. Healthy women aged 18-50 years were randomized to receive a COC containing estradiol valerate/dienogest (2 days estradiol valerate 3 mg, 5 days estradiol valerate 2 mg/dienogest 2 mg, 17 days estradiol valerate 2 mg/dienogest 3 mg, 2 days estradiol valerate 1 mg, 2 days placebo) or ethinylestradiol 0.03 mg/levonorgestrel 0.15 mg in a crossover study design. Women received each treatment for three cycles, with two washout cycles between treatments. The primary efficacy variables were the intra-individual absolute changes in prothrombin fragment 1 + 2 and D-dimer from baseline to cycle three. Data from 29 women were assessed. Intra-individual absolute changes in prothrombin fragment 1 + 2 and D-dimer from baseline to cycle three were less pronounced with estradiol valerate/dienogest than with ethinylestradiol/levonorgestrel. The novel COC containing estradiol valerate/dienogest had similar or less pronounced effects on hemostatic parameters than ethinylestradiol/levonorgestrel.

  3. A randomized, double-blind, placebo-controlled, multicenter study that assessed the endometrial effects of norethindrone acetate plus ethinyl estradiol versus ethinyl estradiol alone.

    PubMed

    Portman, David J; Symons, James P; Wilborn, Walter; Kempfert, Nona J

    2003-02-01

    The purpose of this study was to determine the incidence of endometrial hyperplasia in subjects who receive continuous norethindrone acetate and ethinyl estradiol combinations versus unopposed ethinyl estradiol. Nine hundred forty-five postmenopausal women were randomly selected for 12 months of treatment with one of six blinded norethindrone acetate/ethinyl estradiol combinations (milligrams of norethindrone acetate/micrograms of ethinyl estradiol: 0/5, 0.25/5, 1/5, 0/10, 0.5/10, or 1/10) or to open-label 0.625 mg conjugated equine estrogens/2.5 mg medroxyprogesterone acetate. Endometrial hyperplasia and endometrial proliferation were assessed by biopsy at screening, months 6 and 12. Endometrial hyperplasia developed in 26 subjects: Placebo, 0/5 and 0.25/5 (1 subject each) and 0/10 (23 subjects). Significantly less endometrial proliferation was measured in the 1/5 norethindrone acetate/ethinyl estradiol and other norethindrone acetate/ethinyl estradiol combination groups and in the 0.625 mg conjugated equine estrogens/2.5 mg medroxyprogesterone acetate group, than in unopposed ethinyl estradiol groups (6 months: P <.004; 12 months: P <.001). Treatment with 1/5 norethindrone acetate/ethinyl estradiol and with other norethindrone acetate/ethinyl estradiol combinations significantly reduced endometrial proliferation compared with 0.625 mg conjugated equine estrogens/2.5 mg medroxyprogesterone acetate (6 and 12 months: P <.02). Norethindrone acetate protects the endometrium from estrogen-induced hyperplasia and changes in proliferative status. In addition, norethindrone acetate/ethinyl estradiol-treated subjects had significantly less endometrial proliferation compared with 0.625 mg conjugated equine estrogens/2.5 mg medroxyprogesterone acetate-treated subjects.

  4. Estradiol's effects on learning and neuronal morphology vary with route of administration.

    PubMed

    Garza-Meilandt, Annette; Cantu, Rebecca E; Claiborne, Brenda J

    2006-08-01

    Estrogen's effects on performance and neuronal morphology are variable, and the reasons for this variability are not yet understood. In this study, the authors compared the effects of 2 delivery routes of 17 beta-estradiol on spatial learning and dendritic spine densities in young ovariectomized rats; estradiol was administered by implanted capsules or by daily oral gavage. Estradiol treatment via capsules improved performance in the radial-arm water maze and increased spine densities on dendrites of CA1 pyramidal neurons in the hippocampal formation. In contrast, daily oral administration of estradiol did not affect either measure. These data demonstrate that estradiol delivery is a critical variable in animal studies and that clinical studies comparing the effects of different estradiol treatment routes on cognition are warranted. Copyright 2006 APA, all rights reserved.

  5. Estradiol increases consumption of a chocolate cake mix in female rats.

    PubMed

    Boswell, Karen J; Reid, Larry D; Caffalette, Christopher A; Stitt, Karen T; Klein, Lucas A; Lacroix, Aubrie M; Reid, Meta L

    2006-05-01

    Female Sprague-Dawley rats were given an opportunity to eat chocolate cake mix (CCM) using a common brand of cake mix, while standard laboratory food was also available. They took large amounts of the CCM, often taking more than 20 g in 24 h. Some animals were given a single injection of 1 of 6 doses of estradiol valerate (ranging from 0.09 to 10.0 mg/kg) and others were given vehicle. Estradiol valerate provides for sustained release of estradiol. Those receiving estradiol ate more than those receiving vehicle at doses larger than 0.09 mg/kg. Further, with a dose of 10 mg/kg, greater intake among estradiol-treated females was apparent 2 months post-injection. Methodological issues of neophobia and conditioned avoidance were addressed in the study's design and may explain why increased intakes were observed here in contrast to the consensus that estradiol reduces food intake.

  6. Central expression and anorectic effect of brain-derived neurotrophic factor are regulated by circulating estradiol levels.

    PubMed

    Zhu, Zheng; Liu, Xian; Senthil Kumar, Shiva Priya Dharshan; Zhang, Jing; Shi, Haifei

    2013-03-01

    Estrogens potently suppress food intake. Compelling evidence suggests that estradiol, the primary form of estrogens, reduces food intake by facilitating other anorectic signals. Brain-derived neurotrophic factor (BDNF), like estradiol, appears to suppress food intake by affecting meal size. We hypothesized that estradiol modulates Bdnf expression and the anorectic effect of BDNF. The first goal was to determine whether Bdnf expression was regulated by endogenous estradiol of cycling rats and by cyclic estradiol treatment using ovariectomized rats. Bdnf expression within the ventromedial nucleus of hypothalamus (VMH) was temporally elevated at estrus following the estradiol peak, which coincided with the decline in feeding at this phase of the ovarian cycle. Additionally, food intake and body weight were increased following ovariectomy with a parallel decrease in Bdnf expression in the VMH. All of these alterations were reversed by cyclic estradiol treatment, suggesting that Bdnf expression within the VMH was regulated in an estradiol-dependent manner. The second goal was to determine whether estradiol modulates the anorectic effect of BDNF. Sham-operated estrous rats and ovariectomized rats cyclically treated with estradiol responded to a lower dose of central administration of BDNF to decrease food intake than male rats and oil-treated ovariectomized rats, implying that endogenous estradiol or cyclic estradiol replacement increased the sensitivity to anorectic effect of BDNF. These data indicate that Bdnf expression within the VMH and the anorectic effect of BDNF varied depending on plasma estradiol levels, suggesting that estradiol may regulate BDNF signaling to regulate feeding.

  7. Role of an estradiol regulatory factor-hydroxysteroid dehydrogenase (HSD) in Toxoplasma gondii infection and pathogenicity.

    PubMed

    Zhang, Xiao; Liu, Jing; Li, Muzi; Fu, Yong; Zhang, Taotao; Han, Qian; Liu, Qun

    2017-09-05

    Toxoplasma gondii is an apicomplexan parasite that infects most species of warm-blooded animals, including humans, and causes abortions and severe damage to the fetal central nervous system. During pregnancy, the prevalence of toxoplasmosis increases throughout the second and third quarter of gestation, while the hormones progesterone and estradiol simultaneously increase. Thus, it has been suggested that these hormones could affect parasite reproduction. This study was mainly focused on an estradiol regulatory factor-Hydroxysteroid dehydrogenase (HSD) gene in T. gondii. Our data showed that estradiol promoted Pru (Type II) and VEG (Type III) infection and thus significantly contributed to the pathogenicity of T. gondii in mice. Subsequently, we found that this phenomenon may relate to the interplay of T. gondii and estradiol. We reported that estradiol can enter T. gondii tachyzoites. Bioinformatics analysis showed that T. gondii may have a residual estradiol metabolism-related gene HSD. To verify the gene function, HEK293T cells were transiently transfected with Tg-HSD and gene expression was induced. Then, HPLC (high-performance liquid chromatography) analysis showed that Tg-HSD can efficiently transform estrone into estradiol. Moreover, Tg-HSD -overexpressing parasites showed significantly enhanced pathogenicity and upregulation of estradiol levels in mice. In conclusion, estradiol can promote T. gondii infection in vitro and in vivo, and this may be related to its Tg- HSD gene. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Efficacy of continuous sequential transdermal estradiol and norethindrone acetate in relieving vasomotor symptoms associated with menopause.

    PubMed

    Notelovitz, M; Cassel, D; Hille, D; Furst, K W; Dain, M P; VandePol, C; Skarinsky, D

    2000-01-01

    This study was undertaken to evaluate the efficacy and tolerability of a combination estradiol plus norethindrone acetate transdermal delivery system given in a continuous sequential regimen with transdermal estradiol versus placebo in the treatment of vasomotor symptoms of menopause. This was a 12-week double-blind trial of 220 healthy postmenopausal women with > or = 8 moderate to severe hot flushes and sweating episodes per day. Women were randomly assigned to wear transdermal placebo patches or a transdermal patch releasing 50 microg/d 17beta-estradiol alone (Vivelle) for days 1 to 14 of each cycle and a combination patch releasing 50 microg/d 17beta-estradiol plus 1 of 3 dosage levels (140, 250, or 400 microg/d) of norethindrone acetate (CombiPatch) for days 15 through 28. There was a significant (P <.001) reduction by the second week in the mean number of daily hot flushes from baseline to end point with all 3 doses of estradiol plus norethindrone acetate compared with placebo. Significant (P <.001) reductions in the mean intensity of hot flushes and sweating were also noted with estradiol plus norethindrone acetate compared with placebo. The incidences of adverse events with all 3 doses of estradiol plus norethindrone acetate and with placebo were comparable. An estradiol plus norethindrone acetate transdermal delivery system administered in a continuous sequential regimen with transdermal estradiol was well tolerated and effective for the treatment of moderate to severe vasomotor symptoms in postmenopausal women.

  9. Estradiol and Progesterone have Opposing Roles in the Regulation of Fear Extinction in Female Rats

    PubMed Central

    Graham, Bronwyn M; Daher, Melissa

    2016-01-01

    Fear extinction, the laboratory basis of exposure therapy for anxiety disorders, fluctuates across the female rat estrous cycle, where extinction is enhanced during proestrus (high estradiol and progesterone), and impaired during metestrus (low estradiol and progesterone). During the estrous cycle increasing levels of estradiol precede and then overlap with increased levels of progesterone. We sought to isolate the impact of these hormonal changes on fear extinction by systematically treating ovariectomized female rats with estradiol alone, or in combination with progesterone. We found that estradiol alone facilitated extinction recall, whereas the effects of progesterone on estradiol-treated rats were biphasic and dependent on the time interval between progesterone administration and extinction training. Progesterone potentiated estradiol's facilitation of extinction recall when extinction training occurred 6 h after progesterone administration. However, progesterone abolished estradiol's facilitation of extinction recall when extinction training occurred 24 h after progesterone administration. Furthermore, in naturally cycling rats, blocking progesterone receptor activation during proestrus (when progesterone levels peak) prevented the impairment in extinction recall in rats extinguished during metestrus. These results suggest that in naturally cycling females whereas cyclical increases in estradiol facilitate fear extinction, cyclical increases in progesterone may lead to fear extinction impairments. As extinction training took place after the hormonal treatments had been metabolized, we propose that genomic mechanisms may at least partly mediate the impact of cyclic fluctuations in sex hormones on fear extinction. PMID:26156559

  10. [Oxidative destruction of estradiol after treatment with hydrogen peroxide catalyzed by horseradish peroxidase and methemoglobin].

    PubMed

    Petrenko, Iu M; Matiushin, A I; Titov, V Iu

    1999-01-01

    It is shown that estradiol in the presence of horse radish peroxidase interacts with hydrogen peroxide, which is evidenced by an increase in its optical density at 280 nm. The photometering of samples containing estradiol and horse radish peroxidase upon their titration with hydrogen peroxide indicated that the increase in optical density stops after introducing hydrogen peroxide equimolar in concentration to estradiol. The stoichiometric ratio of estradiol consumed during oxidative destruction to hydrogen peroxide was 1:1. In the presence of ascorbate, the oxidative destruction of estradiol by the action of hydrogen peroxide, catalyzed by horse radish peroxidase, was observed only after a latent period and showed the same regularities as in the absence of ascorbate. It was found by calorimetry that, during the latent period, estradiol catalyzes the degradation of hydrogen peroxide and ascorbate without undergoing oxidative destruction. The substrates of the peroxidase reaction benzidine, 1-naphthol, and phenol interact with hydrogen peroxide in the presence of ascorbate and horse radish peroxidase in a similar way. Presumably, upon interaction with hydrogen peroxide in the presence of horse radish peroxidase, estradiol, like other substrates of this reaction, undergoes oxidative destruction by the mechanism of peroxidase reaction. It is shown that oxidative destruction of estradiol by the action of hydrogen peroxide can also be catalyzed by methemoglobin by the same mechanism. These data are important for understanding the role of estradiol in the organism and the pathways of its metabolic conversions.

  11. Reflex modulation of ovarian estradiol secretion by noxious mechanical stimulation of a hindpaw in anesthetized rats.

    PubMed

    Uchida, Sae; Kagitani, Fusako; Hotta, Harumi

    2012-11-02

    Previously, we demonstrated that electrical stimulation of the superior ovarian nerve in rats reduces the ovarian estradiol secretion rate. In the present study, we examined the effect of noxious mechanical afferent stimulation (pinching) of a hindpaw on the ovarian estradiol secretion rate in rats. The rats were anesthetized on the day of estrus, and the ovarian venous blood was collected intermittently. The secretion rate of estradiol from the ovary was calculated from differences in the estradiol concentration between ovarian venous plasma and systemic arterial blood plasma, and from the flow rate of ovarian venous plasma. Pinching stimulation of a hindpaw for 5 min decreased the estradiol secretion rate from the ovary. A significant reduction of the estradiol secretion rate began at 5 min after the end of the stimulation and lasted for 20 min. The minimum decrease in estradiol secretion rate was 71.1 ± 14.0% of the prestimulus basal values at 15 min after the stimulation ended. The decrease responses of the ovarian estradiol secretion rate were abolished by bilateral severance of the superior ovarian nerves. The efferent activity of the superior ovarian nerves was increased following hindpaw pinching. After spinal transection at the second cervical level, the increased response of the superior ovarian nerve activity by hindpaw pinching was abolished. These results indicate that noxious mechanical stimulation of a hindpaw decreases the estradiol secretion rate from the ovary, and that the response is due to reflex activation of ovarian sympathetic nerves, mediated by supraspinal structures.

  12. Estradiol and Progesterone have Opposing Roles in the Regulation of Fear Extinction in Female Rats.

    PubMed

    Graham, Bronwyn M; Daher, Melissa

    2016-02-01

    Fear extinction, the laboratory basis of exposure therapy for anxiety disorders, fluctuates across the female rat estrous cycle, where extinction is enhanced during proestrus (high estradiol and progesterone), and impaired during metestrus (low estradiol and progesterone). During the estrous cycle increasing levels of estradiol precede and then overlap with increased levels of progesterone. We sought to isolate the impact of these hormonal changes on fear extinction by systematically treating ovariectomized female rats with estradiol alone, or in combination with progesterone. We found that estradiol alone facilitated extinction recall, whereas the effects of progesterone on estradiol-treated rats were biphasic and dependent on the time interval between progesterone administration and extinction training. Progesterone potentiated estradiol's facilitation of extinction recall when extinction training occurred 6 h after progesterone administration. However, progesterone abolished estradiol's facilitation of extinction recall when extinction training occurred 24 h after progesterone administration. Furthermore, in naturally cycling rats, blocking progesterone receptor activation during proestrus (when progesterone levels peak) prevented the impairment in extinction recall in rats extinguished during metestrus. These results suggest that in naturally cycling females whereas cyclical increases in estradiol facilitate fear extinction, cyclical increases in progesterone may lead to fear extinction impairments. As extinction training took place after the hormonal treatments had been metabolized, we propose that genomic mechanisms may at least partly mediate the impact of cyclic fluctuations in sex hormones on fear extinction.

  13. A Comparison of the Effects of Transdermal Estradiol and Estradiol Valerate on Endometrial Receptivity in Frozen-thawed Embryo Transfer Cycles: A Randomized Clinical Trial

    PubMed Central

    Davar, Robab; Janati, Sima; Mohseni, Fereshteh; Khabazkhoob, Mehdi; Asgari, Soheila

    2016-01-01

    Background: The purpose of this study was to determine the optimal endometrial preparation protocol by comparing the clinical outcome of two methods of endometrial preparation in frozen-thawed embryo transfer (FET) cycles, including that is, oral estradiol and 17ß-estradiol transdermal patch. Methods: In this randomized controlled trial, women underwent either conventional IVF or intracytoplasmic sperm injection (ICSI) who had at least two top-quality embryos appropriate for cryopreservation and frozen embryos from previous cycles. In the study group (n=45), 17-B estradiol transdermal patches 100 μg were applied from the second day of the cycle and continued every other day. Then, each patch was removed after four days. In the control group (n=45), oral estradiol valerate 6 mg was started at the same time and continued daily. Results: There was a significant difference in estradiol level on the day of progesterone administration and the day of embryo transfer between the two groups (p= 0.001 in both), but no significant difference was observed between them in biochemical and clinical pregnancy rates (32.6% vs. 33.3%, p=1.000 and 30.2% vs. 33.3%, p=0.810, respectively). Conclusion: It is suggested that estradiol transdermal patches be used instead of oral estradiol in FET cycles. Due to the reduced costs, drug dose, and emotional stress as well as the simplicity of the protocol for patients. PMID:27141464

  14. A vaginal estradiol softgel capsule, TX-004HR, has negligible to very low systemic absorption of estradiol: Efficacy and pharmacokinetic data review.

    PubMed

    Simon, James A; Archer, David F; Constantine, Ginger D; Pickar, James H; Amadio, Julia M; Bernick, Brian; Graham, Shelli; Mirkin, Sebastian

    2017-05-01

    This paper reviews the efficacy, safety, and systemic absorption of estradiol with TX-004HR, an investigational, low-dose 17β-estradiol vaginal softgel capsule, designed to treat vulvar and vaginal atrophy (VVA) in postmenopausal women, with an improved user experience. In phase 2 (NCT02449902) and phase 3 REJOICE (NCT02253173) studies, TX-004HR significantly improved the proportions of vaginal superficial and parabasal cells and vaginal pH, and in the phase 3 study decreased the severity of dyspareunia, vaginal dryness, and vulvar and/or vaginal itching or irritation. In two randomized, phase 1 trials, estradiol Cmax and AUC0-24 were significantly lower with 10μg and 25μg TX-004HR than with the same doses of an approved vaginal estradiol tablet. A substudy (n=72) of the REJOICE trial showed that estradiol Cavg and AUC0-24 with 4μg and 10μg TX-004HR were not different from placebo on days 1 and 14. While TX-004HR 25μg was associated with higher Cavg and AUC0-24 versus placebo on days 1 and 14, these levels remained within the postmenopausal range. Estradiol day-84 values for all three doses were not different from placebo, demonstrating no estradiol accumulation. All TX-004HR doses were well tolerated and had an acceptable safety profile in all reviewed studies. The local vaginal efficacy of TX-004HR was significantly better than that of placebo, while the overall safety profile was similar to that of placebo. Negligible to very low systemic estradiol absorption was observed whether given at 4, 10, or 25μg. If approved, TX-004HR may be an alternative option for women with symptomatic VVA without increasing mean systemic estradiol absorption above postmenopausal levels. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Trapping of Rb Atoms by ac Electric Fields

    SciTech Connect

    Schlunk, Sophie; Marian, Adela; Geng, Peter; Meijer, Gerard; Schoellkopf, Wieland; Mosk, Allard P.

    2007-06-01

    We demonstrate trapping of an ultracold gas of neutral atoms in a macroscopic ac electric trap. Three-dimensional confinement is obtained by switching between two saddle-point configurations of the electric field. Stable trapping is observed in a narrow range of switching frequencies around 60 Hz. The dynamic confinement of the atoms is directly visualized at different phases of the ac switching cycle. We observe about 10{sup 5} Rb atoms in the 1 mm{sup 3} large and several microkelvins deep trap with a lifetime of approximately 5 s.

  16. Low Doses of 17α-Estradiol and 17β-Estradiol Facilitate, Whereas Higher Doses of Estrone and 17α- and 17β-Estradiol Impair, Contextual Fear Conditioning in Adult Female Rats

    PubMed Central

    Barha, Cindy K; Dalton, Gemma L; Galea, Liisa AM

    2010-01-01

    Estrogens are known to exert significant structural and functional effects in the hippocampus of adult rodents. In particular, 17β-estradiol can improve, impair, or have no effect on hippocampus-dependent learning and memory depending on dose and time of administration. The effects of other forms of estrogen, such as estrone and 17α-estradiol, on hippocampus-dependent learning have not been as thoroughly investigated. Therefore, the purpose of this study was to investigate the effects of 17β-estradiol, estrone, and 17α-estradiol at three different doses on two different tasks: hippocampus-dependent contextual fear conditioning and hippocampus-independent cued fear conditioning. Adult ovariectomized female rats were injected with one of the estrogens at one of the three doses 30 mins before conditioning to assess the rapid effects of these estrogens on acquisition. Twenty-four hours later memory for the context was examined and 1 h later memory for the cue (tone) was assessed. Levels of synaptophysin were examined in the dorsal hippocampus of rats to identify a potential synaptic correlate of hormonal effects on contextual fear conditioning. Low 17β-estradiol and 17α-estradiol enhanced, whereas high 17β-estradiol and 17α-estradiol impaired, contextual fear conditioning. Only the middle dose of estrone severely impaired contextual fear conditioning. Estrogens did not alter performance in the hippocampus-independent cued task. Synaptophysin expression was increased by estrone (at a middle and high dose) and 17β-estradiol (at a middle dose) in the CA3 region of the hippocampus and was not correlated with cognition. The results of this study indicate that estradiol can positively or negatively influence hippocampus-dependent learning and memory, whereas estrone impairs hippocampus-dependent learning and memory in a dose-dependent manner. These results have important therapeutic implications, as estrone, a main component of a widely used hormone replacement

  17. Energy metabolism and hindbrain AMPK: regulation by estradiol.

    PubMed

    Briski, Karen P; Ibrahim, Baher A; Tamrakar, Pratistha

    2014-03-01

    Nerve cell energy status is screened within multiple classically defined hypothalamic and hindbrain components of the energy balance control network, including the hindbrain dorsal vagal complex (DVC). Signals of caudal DVC origin have a physiological role in glucostasis, e.g., maintenance of optimal supply of the critical substrate fuel, glucose, through control of motor functions such as fuel consumption and gluco-counterregulatory hormone secretion. A2 noradrenergic neurons are a likely source of these signals as combinatory laser microdissection/high-sensitivity Western blotting reveals expression of multiple biomarkers for metabolic sensing, including adenosine 5'-monophosphate-activated protein kinase (AMPK). Hypoglycemia elicits estradiol-dependent sex differences in A2 AMPK activation as phospho-AMPK (pAMPK) expression is augmented in male and ovariectomized (OVX) female, but not estrogen-replaced, OVX rats. This dichotomy may reflect, in part, estradiol-mediated up-regulation of glycolytic and tricarboxylic acid cycle enzyme expression during hypoglycemia. Our new model for short-term feeding abstinence has physiological relevance to planned (dieting) or unplanned (meal delay) interruption of consumption in modern life, which is negatively correlated with appetite control and obesity, and is useful for investigating how estrogen may mitigate the effects of disrupted fuel acquisition on energy balance via actions within the DVC. Estradiol reduces DVC AMPK activity after local delivery of the AMP mimic, 5-aminoimidazole-4-carboxamide-riboside, or cessation of feeding for 12 h but elevates pAMPK expression when these treatments are combined. These data suggest that estrogen maintains cellular energy stability over periods of suspended fuel acquisition and yet optimizes, by DVC AMPK-dependent mechanisms, counter-regulatory responses to metabolic challenges that occur during short-span feeding abstinence.

  18. Minireview: Animal studies on the role of 50/60-Hertz magnetic fields in carcinogenesis

    SciTech Connect

    Loescher, W.; Mevissen, M. )

    1994-01-01

    A number of epidemiological studies have suggested that exposure to 50/60-Hz magnetic fields (MF) from power lines and electrical equipment may be associated with a modestly increased incidence of various type of cancer. Laboratory studies have indicated that nonionizing radiation has no mutagenic effect, i.e. does not initiate cancer. Thus, if 50/60-Hz MF are truly associated with an increased risk of cancer, then these fields must act as a promoter or co-promoter of cancer in cells that have already been initiated. This paper reviews the evidence produced by animal studies. As shown in this review, the available animal data on 50/60-Hz MF exposures seem to indicate that intermediate MF exposure exerts co-promoting effects in different tumor models, particularly cocarcinogenesis models of breast cancer while chronic (up to life-time) exposure may exert promoting effects on [open quotes]spontaneous[close quotes] development of certain tumors. The tumor promoting or co-promoting effects of 50/60-Hz MF exposure found in several animal studies could relate to actions of MF on gene expression, immune surveillance, and Ca[sup 2+] homeostasis as demonstrated by in vitro experiments in cell cultures. However, the most plausible evidence of an in vivo effect of MF exposure which could be related to tumor promotion is reduction of circulating levels of melatonin, i.e. a hormone which is inhibitory to the growth of a wide range of cancers, particularly breast cancer. Animal studies have shown that 50-Hz MF exposure at fluxes as low as 0.3-1 [mu]Tesla significantly reduces nocturnal melatonin levels in plasma. While decrease of melatonin levels alone could explain tumor promoting or copromoting effects of MF exposure, recent data indicate that MF exposure also impairs the effects of melatonin at the cellular level. The oncostatic effect of melatonin on proliferation of a human breast cancer cell line was antagonized by 60-Hz MF exposure at a flux density of 1 [mu]Tesla.

  19. Methylation of the chicken vitellogenin gene: influence of estradiol administration.

    PubMed Central

    Meijlink, F C; Philipsen, J N; Gruber, M; Ab, G

    1983-01-01

    The degree of methylation of the chicken vitellogenin gene has been investigated. Upon induction by administration of estradiol to a rooster, methyl groups at specific sites near the 5'-end of the gene are eliminated. The process of demethylation is slower than the activation of the gene. Demethylation is therefore probably not a prerequisite to gene transcription. At least two other sites in the coding region of the gene are methylated in the liver of estrogenized roosters, but not in the liver of a laying hen, where the gene is naturally active. Images PMID:6298743

  20. HT update: spotlight on estradiol/norethindrone acetate combination therapy

    PubMed Central

    Casey, Colleen L; Murray, Christine A

    2008-01-01

    The goal of postmenopausal hormone therapy is to alleviate the symptoms that are associated with the loss of estrogen. Many formulations of estrogen and progestin are available, depending on the needs and circumstances of each individual woman. For postmenopausal women, the choice of whether or not to begin therapy requires knowledge of the risks and benefits of estrogen and/or progestin replacement. The purpose of this review is to describe the risks and benefits of hormonal therapy, focusing on estradiol/norethindrone acetate combination therapy. PMID:18488874

  1. HT update: spotlight on estradiol/norethindrone acetate combination therapy.

    PubMed

    Casey, Colleen L; Murray, Christine A

    2008-01-01

    Abstract: The goal ofpostmenopausal hormone therapy is to alleviate the symptoms that are associated with the loss of estrogen. Many formulations of estrogen and progestin are available, depending on the needs and circumstances of each individual woman. For postmenopausal women, the choice of whether or not to begin therapy requires knowledge of the risks and benefits of estrogen and/or progestin replacement. The purpose of this review is to describe the risks and benefits of hormonal therapy, focusing on estradiol/norethindrone acetate combination therapy.

  2. 2-Hydroxy-4-glutathion-S-yl-17beta-estradiol and 2-hydroxy-1-glutathion-S-yl-17beta-estradiol produce oxidative stress and renal toxicity in an animal model of 17beta-estradiol-mediated nephrocarcinogenicity.

    PubMed

    Butterworth, M; Lau, S S; Monks, T J

    1998-01-01

    Chronic exposure of male Syrian hamsters to a variety of estrogens has been linked with a high incidence of renal carcinoma. The basis of this species and tissue specificity remains to be resolved. We have recently shown that (i) 17beta-estradiol is nephrotoxic in the hamster in a manner dependent upon the activity of gamma-glutamyl transpeptidase and (ii) 17beta-estradiol is metabolized to a variety of catechol estrogen glutathione conjugates (Butterworth et al., Carcinogenesis, 18, 561-567, 1997). We report that the catechol estrogen glutathione conjugates exhibit redox properties similar to those of the catechol estrogens, and maintain the ability to generate superoxide radicals. Administration of 2-hydroxy-4-glutathion-S-yl-17beta-estradiol or 2-hydroxy-1-glutathion-S-yl-17beta-estradiol (0.27-5.0 micromol/kg) to Syrian hamsters, produces mild nephrotoxicity. Repeated daily administration of 2-hydroxy-4-glutathion-S-yl-17beta-estradiol causes a sustained elevation in urinary markers of renal damage and in the concentration of renal protein carbonyls and lipid hydroperoxides. Catechol estrogen oxidation and conjugation of glutathione in the liver, followed by the selective uptake of the redox active conjugates in tissues rich in gamma-glutamyl transpeptidase may contribute to 17beta-estradiol-induced renal tumors in the hamster.

  3. Numerical Analysis of Induced Current in Human Head Exposed to Nonuniform Magnetic Field Including Harmonics

    NASA Astrophysics Data System (ADS)

    Tarao, Hiroo; Hayashi, Noriyuki; Isaka, Katsuo

    In this paper, induced currents in an anatomical head model exposed to a non-uniform ELF magnetic field (B-field) including harmonics are numerically calculated, and are discussed based on the basic restriction established by International Commission on Non-Ionizing Radiation Protection (ICNIRP). A casual hair dryer of 100V and 1.2kW is chosen as a typical source of the non-uniform B-field including both the fundamental and second harmonic components. The B-field distribution around the hair dryer is estimated by using the 3-orthogonal magnetic dipole moments, which are derived from a couple of measured values around it. The high-resolution human head model used is constructed based on the MRI images of a real human, and consists of six kinds of tissues (bone, brain, eyeballs, muscle, skin and blood). So-called impedance method is used for the numerical calculation of the induced current. The numerical results show that the maximum values of the induced current of 17µA/m2, for the 60Hz component, which is about 1/120 of the ICNIRP basic restriction appear in the muscle near the eyeball when the hair dryer is used from the side of the head model, and the averaged current in the eyeballs that have the highest conductivity is the highest among the six tissues. It is also demonstrated that the induced current due to the 120Hz B-field becomes comparable to the 60Hz current although the magnitude of the 120Hz B-field is much smaller than that of the 60Hz B-field.

  4. Influence of pulsating magnetic field on softening behavior of cold rolled AISI 4340 steel at room temperature

    SciTech Connect

    Prasad, S.N.; Singh, P.N.; Singh, V.

    1996-06-15

    The mechanical behavior of a ferromagnetic material is influenced by presence of magnetic field. The rate of stress relaxation in nickel increases by a.c. magnetic field of 11 Oersted (Oe) and 60 Hz. The application of 800 Oe steady magnetic field accelerates the process of creeping in high purity iron. The purpose of the present investigation was to examine the influence of pulsating magnetic field of 942 Oe, produced by a.c. current (50Hz), on the softening behavior of AISI 4340 steel, cold rolled to 20, 60, and 80%.

  5. Dissipation and transformation of 17β-estradiol-17-sulfate in soil-water systems.

    PubMed

    Bai, Xuelian; Casey, Francis X M; Hakk, Heldur; DeSutter, Thomas M; Oduor, Peter G; Khan, Eakalak

    2013-09-15

    In the environment, estrogen conjugates can be precursors to the endocrine-disrupting free estrogens, 17β-estradiol (E2) and estrone (E1). Compared to other estrogen conjugates, 17β-estradiol-17-sulfate (E2-17S) is detected at relatively high concentrations and frequencies in animal manure and surface runoff from fields receiving manure. To elucidate the lifecycle of manure-borne estrogens and their conjugates in the environment, the fate of radiolabelled E2-17S in agricultural soils was investigated using laboratory batch studies with soils of different organic carbon (OC) content (1.29% for topsoil versus 0.26% for subsoil). E2-17S was found relatively persistent in the aqueous phase throughout the duration of the 14 d experiment. The aqueous E2-17S persisted longer in the subsoil (half-lives (DT₅₀)=64-173 h) than the topsoil (DT₅₀=4.9-26 h), and the aqueous persistence of E2-17S depended on its initial concentration. The major transformation pathway was hydroxylation, yielding mono- and di-hydroxy-E2-17S (OH-E2-17S and diOH-E2-17S). Free estrogens, E2 and E1, were only observed in the sorbed phase of the soil at low concentrations (∼1% of applied dose), which demonstrated that deconjugation and subsequent oxidation had occurred. Although deconjugation was not a major pathway, E2-17S could be a precursor of free estrogens in the environment. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Fetal Hypothalamus-Pituitary-Adrenal Responses to Estradiol Sulfate

    PubMed Central

    2011-01-01

    Estradiol (E2) is an important modifier of the activity of the fetal hypothalamus-pituitary-adrenal axis. We have reported that estradiol-3-sulfate (E2SO4) circulates in fetal blood in far higher concentrations than E2 and that the fetal brain expresses steroid sulfatase, required for local deconjugation of E2SO4. We performed the present study to test the hypothesis that chronic infusion of E2SO4 chronically increases ACTH and cortisol secretion and that it shortens gestation. Chronically catheterized fetal sheep were treated with E2SO4 intracerebroventricular (n = 5), E2SO4 iv (n = 4), or no steroid infusion (control group, n = 5). Fetuses were subjected to arterial blood sampling every other day until spontaneous birth for plasma hormone analysis. Treatment with E2SO4 attenuated preparturient increases in ACTH secretion near term without affecting the ontogenetic rise in plasma cortisol. Infusion of E2SO4 intracerebroventricularly significantly increased plasma E2, plasma E2SO4, and plasma progesterone and shortened gestation compared with all other groups. These results are consistent with the conclusion that E2SO4: 1) interacts with the hypothalamus-pituitary-adrenal axis primarily by stimulating cortisol secretion and inhibiting ACTH and pro-ACTH secretion by negative feedback; and 2) stimulates the secretion of E2 and E2SO4. We conclude that the endocrine response to E2SO4 in the fetus is not identical with the response to E2. PMID:21952234

  7. Effects of Panax ginseng, zearalenol, and estradiol on sperm function.

    PubMed

    Gray, Sandra L; Lackey, Brett R; Boone, William R

    2016-07-01

    Estrogen signaling pathways are modulated by exogenous factors. Panax ginseng exerts multiple activities in biological systems and is classified as an adaptogen. Zearalenol is a potent mycoestrogen that may be present in herbs and crops arising from contamination or endophytic association. The goal of this study was to investigate the impact of P. ginseng, zearalenol and estradiol in tests on spermatozoal function. The affinity of these compounds for estrogen receptor (ER)-alpha and beta (ERα and ERβ)-was assessed in receptor binding assays. Functional tests on boar spermatozoa motility, movement and kinematic parameters were conducted using a computer-assisted sperm analyzer. Tests for capacitation, acrosome reaction (AR), and chromatin decondensation in spermatozoa were performed using microscopic analysis. Zearalenol-but not estradiol (E2)- or ginseng-treated spermatozoa-decreased the percentage of overall, progressive, and rapid motile cells. Zearalenol also decreased spontaneous AR and increased chromatin decondensation. Ginseng decreased chromatin decondensation in response to calcium ionophore and decreased AR in response to progesterone (P4) and ionophore. Zearalenol has adverse effects on sperm motility and function by targeting multiple signaling cascades, including P4, E2, and calcium pathways. Ginseng protects against chromatin damage and thus may be beneficial to reproductive fitness.

  8. The Estradiol-Dihydrotestosterone model of prostate cancer

    PubMed Central

    Friedman, A Edward

    2005-01-01

    Background The exact relationship between hormonal activity and prostate cancer(PCa) has not yet been clearly defined. One of the key hormones associated with PCa is testosterone(T). However, both in vitro and in vivo studies have shown that under some conditions T is capable of either promoting PCa growth or death. This article proposes a theory which resolves this apparent paradox. Model The Estradiol-Dihydrotestosterone(E-D) model introduced in this paper proposes that 17β-estradiol(E2) is essential for initiating the growth of PCa cells through the formation of telomeres. It also proposes that T is responsible for increasing the expression of proteins which cause apoptosis, or programmed cell death, and that 5α-dihydrotestosterone(DHT) is essential for preventing this. In addition, it is known that some T is converted to both E2 and DHT, which means that depending on the conditions, T is capable of either promoting the growth of or the killing of PCa. PMID:15777479

  9. Human melatonin during continuous magnetic field exposure

    SciTech Connect

    Graham, C.; Cook, M.R.; Riffle, D.W.

    1997-05-01

    This report describes the third in a series of double-blind, laboratory-based studies that were aimed at determining the effects of nocturnal exposure to power frequency magnetic fields on blood levels of melatonin in human volunteers. The two earlier studies evaluated effects on melatonin of intermittent exposure to 60 Hz circularly polarized magnetic fields at 10 and 200 mG. No overall effects on melatonin levels were found. In the present study, men were exposed continuously rather than intermittently through the night to the same 200 mG magnetic field condition that was used previously; again, no overall effects on melatonin levels were found. The authors conclude that the intermittent and continuous exposure conditions used in the laboratory to date are not effective in altering nocturnal blood levels of melatonin in human volunteers.

  10. THE PATHOBIOLOGY OF 17B-ESTRADIOL IN SUMMER FLOUNDER, PARALICHTYS DENTATUS

    EPA Science Inventory

    Estradiol has been shown to cause increased vitellogenin (VtG) concentrations in male fish. The intent of this study was to evaluate the pathobiology associated with exposure to 17 -estradiol (E2) on liver, gonad, and kidney tissues of summer flounder, Paralichthys dentatus. Juve...

  11. Luteinizing hormone secretion as influenced by age and estradiol in the prepubertal gilt

    USDA-ARS?s Scientific Manuscript database

    The aim of this study was to determine if there is an age related reduction in the sensitivity of the negative feedback action of estradiol on luteinizing hormone (LH) secretion in the prepubertal gilt. Ovariectomized gilts at 90 (n = 12), 150 (n = 11) or 210 (n = 12) days of age received estradiol ...

  12. THE PATHOBIOLOGY OF 17B-ESTRADIOL IN SUMMER FLOUNDER, PARALICHTYS DENTATUS

    EPA Science Inventory

    Estradiol has been shown to cause increased vitellogenin (VtG) concentrations in male fish. The intent of this study was to evaluate the pathobiology associated with exposure to 17 -estradiol (E2) on liver, gonad, and kidney tissues of summer flounder, Paralichthys dentatus. Juve...

  13. Estradiol alleviates the ischemic brain injury-induced decrease of neuronal calcium sensor protein hippocalcin.

    PubMed

    Koh, Phil-Ok

    2014-10-17

    Estradiol has protective and reparative effects in neurodegenerative diseases. Hippocalcin is a neuronal calcium-sensor protein that acts as a calcium buffer to regulate the intracellular concentration of Ca(2+). This study was investigated to elucidate whether estradiol regulates hippocalcin expression in a focal cerebral ischemia model and glutamate-treated neuronal cells. An ovariectomy was performed in adult female rats, and vehicle or estradiol was administered before middle cerebral artery occlusion (MCAO). Cerebral cortex tissues were collected at 24h after MCAO. A proteomic approach revealed that hippocalcin expression decreased in vehicle-treated animals with combined MCAO, while estradiol treatment attenuated this decrease. Reverse transcription-PCR and Western blot analyses also showed that estradiol administration prevented the MCAO injury-induced decrease in hippocalcin expression. In cultured hippocampal cells, glutamate exposure increased the intracellular Ca(2+) concentration, which was rescued by the presence of estradiol. Moreover, glutamate toxicity decreased hippocalcin expression, whereas estradiol attenuated this decrease. Together, these findings suggest that estradiol has a neuroprotective function by regulating hippocalcin expression and intracellular Ca(2+) levels in ischemic brain injury.

  14. Exogenous estradiol alters gonadal growth and timing of temperature sex determination in gonads of sea turtle.

    PubMed

    Díaz-Hernández, Verónica; Marmolejo-Valencia, Alejandro; Merchant-Larios, Horacio

    2015-12-01

    Temperature sex determining species offer a model for investigating how environmental cues become integrated to the regulation of patterning genes and growth, among bipotential gonads. Manipulation of steroid hormones has revealed the important role of aromatase in the regulation of the estrogen levels involved in temperature-dependent sex determination. Estradiol treatment counteracts the effect of male-promoting temperature, but the resulting ovarian developmental pattern differs from that manifested with the female-promoting temperature. Hypoplastic gonads have been reported among estradiol-treated turtles; however the estradiol effect on gonadal size has not been examined. Here we focused on the sea turtle Lepidochelys olivacea, which develops hypoplastic gonads with estradiol treatment. We studied the effect of estradiol on cell proliferation and on candidate genes involved in ovarian pattern. We found this effect is organ specific, causing a dramatic reduction in gonadal cell proliferation during the temperature-sensitive period. Although the incipient gonads resembled tiny ovaries, remodeling of the medullary cords and down-regulation of testicular factor Sox9 were considerably delayed. Contrastingly, with ovarian promoting temperature as a cue, exogenous estradiol induced the up-regulation of the ovary factor FoxL2, prior to the expression of aromatase. The strong expression of estrogen receptor alpha at the time of treatment suggests that it mediates estradiol effects. Overall results indicate that estradiol levels required for gonadal growth and to establish the female genetic network are delicately regulated by temperature.

  15. Effects of preovulatory estradiol concentration on embryo survival and pregnancy establishment in beef cows

    USDA-ARS?s Scientific Manuscript database

    The role of estradiol during the preovulatory period on embryo survival and pregnancy establishment has not been characterized in beef cows. We hypothesized that preovulatory estradiol is important for embryo survival and pregnancy establishment in beef cows. In order to establish the importance o...

  16. 17β-Estradiol administration promotes delayed cutaneous wound healing in 40-week ovariectomised female mice.

    PubMed

    Mukai, Kanae; Nakajima, Yukari; Urai, Tamae; Komatsu, Emi; Nasruddin; Sugama, Junko; Nakatani, Toshio

    2016-10-01

    This study investigated the effect of 17β-estradiol on wound healing in 40-week ovariectomised female mice. Thirty-six-week-old female mice were divided into three groups: medication with 17β-estradiol after ovariectomy (OVX + 17β-estradiol), ovariectomy (OVX) and sham (SHAM). The mice received two full-thickness wounds, and the OVX + 17β-estradiol group was administered 17β-estradiol at 0·01 g/day until healing. In the OVX + 17β-estradiol group, the ratio of wound area was significantly smaller than those of the OVX and SHAM groups on days 1-3, 5, 6, 8-12 and 9-12, respectively, the numbers of neutrophils and macrophages were significantly smaller than those on days 3 and 7, the ratio of re-epithelialisation was significantly higher than those on days 3 and 11, the ratio of myofibroblasts was significantly higher than those on day 11 and smaller on day 14, and the ratio of collagen fibres was significantly larger than that of the OVX group on days 7-14. We found that 17β-estradiol administration promotes cutaneous wound healing in 40-week female mice by reducing wound area, shortening inflammatory response, and promoting re-epithelialisation, collagen deposition and wound contraction. Our results suggest that cutaneous wound healing that is delayed because of ageing is promoted by exogenous and continuous 17β-estradiol administration.

  17. Evaluating the role of astrocytes on β-estradiol effect on seizures of Pilocarpine epileptic model.

    PubMed

    Sarfi, Masoumeh; Elahdadi Salmani, Mahmoud; Goudarzi, Iran; Lashkar Boluki, Taghi; Abrari, Kataneh

    2017-02-15

    Epilepsy with periodic and unpredictable seizures is associated with hippocampal glutamate toxicity and tissue reorganization. Astrocytes play an important role in mediating the neuroprotective effects of estradiol and reducing seizure severity. Accordingly, the protective effects of low and high doses of estradiol on behavioral, astrocytic involvement and neuronal survival aspects of Pilocarpine-induced epilepsy were investigated. Lithium- Pilocarpine (30mg/kg) model was used to provoke epilepsy. Βeta-estradiol (2,40μg/µl) was injected subcutaneously from 48 before to 48h after seizure induction. Behavioral convulsions were then monitored and recorded on the day of induction. Four weeks later, glutamine synthetase (GS) activity and the astrocyte transporter GLT-1 expression of the hippocampus were measured. Moreover, hippocampal glutamate and GABA were evaluated to study excitability changes. Finally, neuronal counting in the hippocampus was also performed using Nissl staining. The latency for generalized clonic (GC) convulsions significantly increased while the rate of GC and death significantly reduced due to β-estradiol treatment. GS activity and GLT-1 expression increased in the groups receiving the high dose of β-estradiol and Pilocarpine. Furthermore, the amount of both GABA and glutamate content decreased due to high dose of estradiol, while only GABA increased in Pilocarpine treated rats. Finally, administration of β-estradiol with low and high doses increased and improved the density of nerve cells. It is concluded that chronic administration β-estradiol has anticonvulsant and neuroprotective properties which are plausibly linked to astrocytic activity.

  18. Application of fly ash as an adsorbent for Estradiol in animal waste.

    PubMed

    Norris, Pauline; Hagan, Stephanie; Cohron, Martin; Zhao, Houying; Pan, Wei-Ping; Li, Kawang

    2015-09-15

    The contamination of agricultural ground with estrogen compounds through application of animal wastes is a present concern. At the same time, current uses for waste fly ash having high carbon content are limited. To help mitigate these problems, we examine using waste fly ash as a useful adsorbent for Estradiol in pig waste digests. In this study, Estradiol was added to vials containing water and fly ash from several different power plants. After an extraction process, the amount of Estradiol in the water was measured. Commercial activated carbon was also used for comparison purposes. Vials containing varying concentrations of Estradiol and no trapping material were used as a control. The results from this study indicate that fly ash can be used as a trapping material for Estradiol in water, but that commercially available activated carbon can trap about an order of magnitude more Estradiol than the fly ash and that the effects of the fly ash matrix can both inhibit and promote the solvation of Estradiol into water depending possibly upon pH and cation concentration effects. In addition, preliminary extraction studies using pig waste digest indicate that fly ash can be used as adsorbent for Estradiol present in pig waste. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Dissipation and transformation of 17B-estradiol-17-sulfate in soil-water systems

    USDA-ARS?s Scientific Manuscript database

    Estrogen conjugates are known to be precursors of endocrine-disrupting free estrogens, e.g. 17B-estradiol (E2) and estrone (E1), in the environment. This study investigated the fate of a sulfate conjugated estrogen, 17B-estradiol-17-sulfate (E2-17S), in agricultural soils using laboratory batch stu...

  20. Use of a biotinyl-estradiol derivative to demonstrate estradiol-membrane binding sites on adherent human breast cancer MCF-7 cells.

    PubMed

    Germain, P S; Metezeau, P; Tiefenauer, L X; Kiefer, H; Ratinaud, M H; Habrioux, G

    1993-01-01

    A biotinyl-derivative of 17 beta-estradiol has been used to demonstrate a site of recognition and binding of estradiol located on the plasma membrane of human breast cancer MCF-7 cells by using the biotin/avidin-FITC system. The specificity of this binding has been shown by a displacement of the fluorescent label by 17 beta-estradiol. No displacement was observed when testosterone was added. Quantification of this phenomenon has been shown by laser scanning cytometry while preserving the cells adhesiveness to their growth support as well as their membrane integrity. An analysis by confocal laser scanning microscopy suggested that the fluorescence distribution on MCF-7 cells treated with estradiol-biotin was on the cell periphery. The results obtained are in favour of the recognition and binding site of 17 beta-estradiol located on the plasma membrane of MCF-7 cells and they would indicate that the biological activity of estradiol, among others, could be initiated by an interaction with the membrane.

  1. The Effect of Estradiol on the Growth Plate Chondrocytes of Limb and Spine from Postnatal Mice in vitro: The Role of Estrogen-Receptor and Estradiol Concentration

    PubMed Central

    Shi, Sheng; Zheng, Shuang; Li, Xin-Feng; Liu, Zu-De

    2017-01-01

    Objectives: Skeletal development is a complex process. Little is known about the different response of limb or spine growth plate chondrocytes (LGP or SGP) to the estrogen level and the role of estrogen receptor (ER) during postnatal stage. Methods: LGP and SGP chondrocytes were isolated from 50 one-week mice and treated with different concentrations of 17β-estradiol. Cell viability was measured by cell counting kit-8 (CCK-8). The expression of collagen II and X were evaluated by real-time PCR and Western blotting. Then, the response of LGP or SGP chondrocyte after with or without estradiol and specific ER antagonists to block the effect of ERs were also measured by Western blotting and immunofluorescence. Results: Estradiol promoted the chondrogensis of the chondrocytes in vitro and achieved the maximal expression of type II collagen at the dose of 10-7 M. Additionally, the regulatory effect of estradiol on the chondrogenesis can be mainly relied on ERα. The LGP chondrocytes were more sensitive to the estradiol treatment than SGP in the expression of type II collagen. Conclusions: Estrogen at a pharmacological concentration (10-7 M) could stimulate the maximal production of type II collagen in the growth plate chondrocytes in vitro, which exerts its activity mainly through ERα in the chondrogenesis. Furthermore, the LGP chondrocytes were more sensitive to the estradiol treatment than SGP in the chondrogenesis. PMID:28123350

  2. Human Endometrial Adenocarcinoma Transplanted into Nude Mice: Growth Regulation by Estradiol

    NASA Astrophysics Data System (ADS)

    Satyaswaroop, P. G.; Zaino, R. J.; Mortel, R.

    1983-01-01

    A model for studying the growth of primary tumors of human endometrium and its regulation by 17β -estradiol has been developed in which ovariectomized nude mice are used as recipients. The receptors for sex steroids are maintained during serial transplantation of the tumor in this system. Although the rate of growth of receptor-negative endometrial tumors transplanted into ovariectomized nude mice is unaffected by the sustained presence or absence of estradiol, the growth of receptor-positive tumors is significantly increased by estradiol. Receptor-positive tumors treated with estradiol produced elevated concentrations of progesterone receptor. That the progesterone receptor is functional in this tumor is evident from the induction of estradiol 17β -dehydrogenase activity upon progestin administration. These findings are consistent with receptor-mediated regulation of growth of endometrial carcinoma.

  3. Sexual receptivity facilitated by unesterified estradiol: Dependence on estrogen and progestin receptors and priming dose of estradiol benzoate.

    PubMed

    Domínguez-Ordóñez, Raymundo; García-Juárez, Marcos; Lima-Hernández, Francisco J; Gómora-Arrati, Porfirio; Blaustein, Jeffrey D; González-Flores, Oscar

    2015-12-01

    In some conditions, female sexual behavior in ovariectomized rats can be induced by continuous exposure of estradiol (E2) alone or by a single injection of a high dose of the long-lasting, esterified estradiol benzoate (EB). However, there are inconsistencies in the literature on the role of estrogens during priming or in the facilitation on female sexual behavior in EB-primed rats, as well as the cellular mechanisms involved. Either subcutaneous (sc) or intracerebral (icv) administration of some doses of free unesterified E2, induced lordosis in EB-primed rats. Either sc or icv injection of E2, immediately prior to testing, induced high levels of sexual receptivity when the female rats were primed with an EB sc injection of 2 μg EB. The roles of progesterone receptor (PR) and estrogen receptor on lordosis induced by sc or icv administration of E2 were explored. Tamoxifen or RU486 administrated sc or icv; each reduced lordosis induced by E2. Similarly, antisense oligonucleotides directed at PR-B or total PR (PR-A + PR-B) administrated icv immediately before EB injection inhibited lordosis induced by daily injections of EB. These results suggest that lordosis facilitated by free E2 is dependent on priming dose of EB. Furthermore both ERs and PRs are involved in this action of E2. (c) 2015 APA, all rights reserved).

  4. Degradation of endocrine disrupting chemicals bisphenol A, ethinyl estradiol, and estradiol during UV photolysis and advanced oxidation processes.

    PubMed

    Rosenfeldt, Erik J; Linden, Karl G

    2004-10-15

    The degradation of three endocrine disrupting chemicals (EDCs), bisphenol A, ethinyl estradiol, and estradiol, was investigated via ultraviolet (UV) radiation photolysis and the UV/hydrogen peroxide advanced oxidation process (AOP). These EDCs have been detected at low levels in wastewaters and surface waters in both the United States and European countries, can cause adverse effects on humans and wildlife via interactions with the endocrine system, and thus must be treated before entering the public drinking water supply. Because many EDCs can only be partially removed with conventional water treatment systems, there is a need to evaluate alternative treatment processes. For each EDC tested, direct UV photolysis quantum yields were derived for use with both monochromatic low-pressure (LP) UV lamps and polychromatic medium-pressure (MP) UV lamps and second-order hydroxyl radical rate constants were developed. These parameters were utilized to successfully model UV treatment of the EDCs in laboratory and natural waters. The polychromatic MP UV radiation source was more effective for direct photolysis degradation as compared to conventional LP UV lamps emitting monochromatic UV 254 nm radiation. However, in all cases the EDCs were more effectively degraded utilizing UV/H2O2 advanced oxidation as compared to direct UV photolysis treatment.

  5. Estradiol regulates human QT-interval: acceleration of cardiac repolarization by enhanced KCNH2 membrane trafficking.

    PubMed

    Anneken, Lars; Baumann, Stefan; Vigneault, Patrick; Biliczki, Peter; Friedrich, Corinna; Xiao, Ling; Girmatsion, Zenawit; Takac, Ina; Brandes, Ralf P; Kissler, Stefan; Wiegratz, Inka; Zumhagen, Sven; Stallmeyer, Birgit; Hohnloser, Stefan H; Klingenheben, Thomas; Schulze-Bahr, Eric; Nattel, Stanley; Ehrlich, Joachim R

    2016-02-14

    Modulation of cardiac repolarization by sexual hormones is controversial and hormonal effects on ion channels remain largely unknown. In the present translational study, we therefore assessed the relationship between QTc duration and gonadal hormones and studied underlying mechanisms. We measured hormone levels and QTc intervals in women during clomiphene stimulation for infertility and women before, during, and after pregnancy. Three heterozygous LQT-2 patients (KCNH2-p.Arg752Pro missense mutation) and two unaffected family members additionally were studied during their menstrual cycles. A comprehensive cellular and molecular analysis was done to identify the mechanisms of hormonal QT-interval regulation. High estradiol levels, but neither progesterone nor estradiol/progesterone ratio, inversely correlated with QTc. Consistent with clinical data, in vitro estradiol stimulation (60 pmol/L, 48 h) enhanced IKCNH2. This increase was mediated by estradiol receptor-α-dependent promotion of KCNH2-channel trafficking to the cell membrane. To study the underlying mechanism, we focused on heat-shock proteins. The heat-shock protein-90 (Hsp90) inhibitor geldanamycin abolished estradiol-induced increase in IKCNH2. Geldanamycin had no effect on KCNH2 transcription or translation; nor did it affect expression of estradiol receptors and chaperones. Estradiol enhanced the physical interaction of KCNH2-channel subunits with heat-shock proteins and augmented ion-channel trafficking to the membrane. Elevated estradiol levels were associated with shorter QTc intervals in healthy women and female LQT-2 patients. Estradiol acts on KCNH2 channels via enhanced estradiol-receptor-α-mediated Hsp90 interaction, augments membrane trafficking and thereby increases repolarizing current. These results provide mechanistic insights into hormonal control of human ventricular repolarization and open novel therapeutic avenues. Published on behalf of the European Society of Cardiology. All rights

  6. Estradiol regulates human QT-interval: acceleration of cardiac repolarization by enhanced KCNH2 membrane trafficking

    PubMed Central

    Anneken, Lars; Baumann, Stefan; Vigneault, Patrick; Biliczki, Peter; Friedrich, Corinna; Xiao, Ling; Girmatsion, Zenawit; Takac, Ina; Brandes, Ralf P.; Kissler, Stefan; Wiegratz, Inka; Zumhagen, Sven; Stallmeyer, Birgit; Hohnloser, Stefan H.; Klingenheben, Thomas; Schulze-Bahr, Eric; Nattel, Stanley; Ehrlich, Joachim R.

    2016-01-01

    Background Modulation of cardiac repolarization by sexual hormones is controversial and hormonal effects on ion channels remain largely unknown. In the present translational study, we therefore assessed the relationship between QTc duration and gonadal hormones and studied underlying mechanisms. Methods and results We measured hormone levels and QTc intervals in women during clomiphene stimulation for infertility and women before, during, and after pregnancy. Three heterozygous LQT-2 patients (KCNH2-p.Arg752Pro missense mutation) and two unaffected family members additionally were studied during their menstrual cycles. A comprehensive cellular and molecular analysis was done to identify the mechanisms of hormonal QT-interval regulation. High estradiol levels, but neither progesterone nor estradiol/progesterone ratio, inversely correlated with QTc. Consistent with clinical data, in vitro estradiol stimulation (60 pmol/L, 48 h) enhanced IKCNH2. This increase was mediated by estradiol receptor-α-dependent promotion of KCNH2-channel trafficking to the cell membrane. To study the underlying mechanism, we focused on heat-shock proteins. The heat-shock protein-90 (Hsp90) inhibitor geldanamycin abolished estradiol-induced increase in IKCNH2. Geldanamycin had no effect on KCNH2 transcription or translation; nor did it affect expression of estradiol receptors and chaperones. Estradiol enhanced the physical interaction of KCNH2-channel subunits with heat-shock proteins and augmented ion-channel trafficking to the membrane. Conclusion Elevated estradiol levels were associated with shorter QTc intervals in healthy women and female LQT-2 patients. Estradiol acts on KCNH2 channels via enhanced estradiol-receptor-α-mediated Hsp90 interaction, augments membrane trafficking and thereby increases repolarizing current. These results provide mechanistic insights into hormonal control of human ventricular repolarization and open novel therapeutic avenues. PMID:26271031

  7. Estradiol Attenuates Multiple Tetrodotoxin-Sensitive Sodium Currents in Isolated Gonadotropin-releasing Hormone Neurons

    PubMed Central

    Wang, Yong; Garro, Mona; Kuehl-Kovarik, M. Cathleen

    2010-01-01

    Secretion from gonadotropin-releasing hormone (GnRH) neurons is necessary for the production of gametes and hormones from the gonads. Subsequently, GnRH release is regulated by steroid feedback. However, the mechanisms by which steroids, specifically estradiol, modulate GnRH secretion are poorly understood. We have previously shown that estradiol administered to the female mouse decreases inward currents in fluorescently-labeled GnRH neurons. The purpose of this study was to examine the contribution of sodium currents in the negative feedback action of estradiol. Electrophysiology was performed on GnRH neurons dissociated from young, middle-aged, or old female mice. All mice were ovariectomized; half were estradiol replaced. The amplitude of the sodium current underlying the action potential was significantly decreased in GnRH neurons from young estradiol-treated animals. In addition, in vivo estradiol significantly decreased the transient sodium current amplitude, but prolonged the sodium current inactivation time constant. Estradiol decreased the persistent sodium current amplitude, and induced a significant negative shift in peak current potential. In contrast to results obtained from cells from young reproductive animals, estradiol did not significantly attenuate the sodium current underlying the action potential in cells isolated from middle-aged or old mice. Sodium channels can modulate cell threshold, latency of firing, and action potential characteristics. The reduction of sodium current amplitude by estradiol suggests a negative feedback on GnRH neurons, which could lead to a downregulation of cell excitability and hormone release. The attenuation of estradiol regulation in peripostreproductive and postreproductive animals could lead to dysregulated hormone release with advancing age. PMID:20580637

  8. 76 FR 75886 - Determination That DEMULEN 1/50-28 (Ethinyl Estradiol; Ethynodiol Diacetate) Tablet and Four...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ... estradiol; 4901 Searle ethynodiol diacetate) Pkwy., Skokie, Tablet, 0.05 mg; 1 mg. IL 60077. NDA 018160 DEMULEN 1/35-28 Do. (ethinyl estradiol; ethynodiol diacetate) Tablet, 0.035 mg; 1 mg. ] NDA 018168 DEMULEN 1/35-21 Do. (ethinyl estradiol; ethynodiol diacetate) Tablet, 0.035 mg; 1 mg. NDA 019190...

  9. An expansion plan for the 60 Hz power distribution system at KSC: LC-39 substations load allocation plan

    NASA Technical Reports Server (NTRS)

    Kalu, Alex

    1990-01-01

    The increasing load density in the LC-39 area of Kennedy Space Center (KSC) can be met by either modifying the existing substation and increasing its capacity or by planning an additional new substation. Evidence that the later approach is more economical, enhances the system reliability, and would produce more satisfactory performance indices is provided. Network theory is the basis for the optimal location determination of the proposed substation. A load reallocation plan which minimizes investment cost and power losses and meets other desirable system features is drafted. The report should be useful to the system designer and can be a useful guideline for future facility planners.

  10. From sunlight in space to 60 Hz on earth - The losses along the way. [satellite solar power transmission efficiency

    NASA Technical Reports Server (NTRS)

    Denman, O. S.

    1978-01-01

    The space-to-ground links for the Solar Power Satellite System are discussed in terms of worst, best, and nominal efficiency used in the development of the preliminary design. An uncertainty analysis of this design illustrates the effect of link efficiency on SPS size and mass. It is shown that a solar power satellite can deliver power to a ground-based utility for 4 to 5 cents per kWh, depending on the efficiency of the solar cells available in 1987. The overall efficiency of converting sunlight in space to electric power delivered to utilities ranged from 3.83% for the worst combination of efficiencies to 9.5% for the best, with a nominal efficiency of 7.12%.

  11. Estradiol Regulates Brown Adipose Tissue Thermogenesis via Hypothalamic AMPK

    PubMed Central

    Martínez de Morentin, Pablo B.; González-García, Ismael; Martins, Luís; Lage, Ricardo; Fernández-Mallo, Diana; Martínez-Sánchez, Noelia; Ruíz-Pino, Francisco; Liu, Ji; Morgan, Donald A.; Pinilla, Leonor; Gallego, Rosalía; Saha, Asish K.; Kalsbeek, Andries; Fliers, Eric; Bisschop, Peter H.; Diéguez, Carlos; Nogueiras, Rubén; Rahmouni, Kamal; Tena-Sempere, Manuel; López, Miguel

    2014-01-01

    Summary Estrogens play a major role in the modulation of energy balance through central and peripheral actions. Here, we demonstrate that central action of estradiol (E2) inhibits AMP-activated protein kinase (AMPK) through estrogen receptor alpha (ERα) selectively in the ventromedial nucleus of the hypothalamus (VMH), leading to activation of thermogenesis in brown adipose tissue (BAT) through the sympathetic nervous system (SNS) in a feeding-independent manner. Genetic activation of AMPK in the VMH prevented E2-induced increase in BAT-mediated thermogenesis and weight loss. Notably, fluctuations in E2 levels during estrous cycle also modulate this integrated physiological network. Together, these findings demonstrate that E2 regulation of the VMH AMPK-SNS-BAT axis is an important determinant of energy balance and suggest that dysregulation in this axis may account for the common changes in energy homeostasis and obesity linked to dysfunction of the female gonadal axis. PMID:24856932

  12. Seizure facilitating activity of the oral contraceptive ethinyl estradiol.

    PubMed

    Younus, Iyan; Reddy, Doodipala Samba

    2016-03-01

    Contraceptive management is critical in women with epilepsy. Although oral contraceptives (OCs) are widely used by many women with epilepsy, little is known about their impact on epileptic seizures and epileptogenesis. Ethinyl estradiol (EE) is the primary component of OC pills. In this study, we investigated the pharmacological effect of EE on epileptogenesis and kindled seizures in female mice using the hippocampus kindling model. Animals were stimulated daily with or without EE until generalized stage 5 seizures were elicited. EE treatment significantly accelerated the rate of epileptogenesis. In acute studies, EE caused a significant decrease in the afterdischarge threshold and increased the incidence and severity of seizures in fully-kindled mice. In chronic studies, EE treatment caused a greater susceptibility to kindled seizures. Collectively, these results are consistent with moderate proconvulsant-like activity of EE. Such excitatory effects may affect seizure risk in women with epilepsy taking OC pills.

  13. Relationship between Carotenoids, Retinol, and Estradiol Levels in Older Women.

    PubMed

    Maggio, Marcello; de Vita, Francesca; Lauretani, Fulvio; Bandinelli, Stefania; Semba, Richard D; Bartali, Benedetta; Cherubini, Antonio; Cappola, Anne R; Ceda, Gian Paolo; Ferrucci, Luigi

    2015-08-05

    In vitro evidence suggests anti-estrogenic properties for retinol and carotenoids, supporting a chemo-preventive role of these phytochemicals in estrogen-dependent cancers. During aging there are significant reductions in retinol and carotenoid concentrations, whereas estradiol levels decline during menopause and progressively increase from the age of 65. We aimed to investigate the hypothesis of a potential relationship between circulating levels of retinol, carotenoids, and estradiol (E2) in a cohort of late post-menopausal women. We examined 512 women ≥ 65 years from the InCHIANTI study. Retinol, α-caroten, β-caroten, β-criptoxantin, lutein, zeaxanthin, and lycopene levels were assayed at enrollment (1998-2000) by High-Performance Liquid Chromatography. Estradiol and testosterone (T) levels were assessed by Radioimmunometry (RIA) and testosterone-to-estradiol ratio (T/E2), as a proxy of aromatase activity, was also calculated. General linear models adjusted for age (Model 1) and further adjusted for other confounders including Body Mass Index (BMI) BMI, smoking, intake of energy, lipids, and vitamin A; C-Reactive Protein, insulin, total cholesterol, liver function, and testosterone (Model 2) were used to investigate the relationship between retinol, carotenoids, and E2 levels. To address the independent relationship between carotenoids and E2 levels, factors significantly associated with E2 in Model 2 were also included in a fully adjusted Model 3. After adjustment for age, α-carotene (β ± SE = -0.01 ± 0.004, p = 0.02) and β-carotene (β ± SE = -0.07 ± 0.02, p = 0.0007) were significantly and inversely associated with E2 levels. α-Carotene was also significantly and positively associated with T/E2 ratio (β ± SE = 0.07 ± 0.03, p = 0.01). After adjustment for other confounders (Model 2), the inverse relationship between α-carotene (β ± SE = -1.59 ± 0.61, p = 0.01), β-carotene (β ± SE = -0.29 ± 0.08, p = 0.0009), and E2 persisted whereas the

  14. Relationship between Carotenoids, Retinol, and Estradiol Levels in Older Women

    PubMed Central

    Maggio, Marcello; de Vita, Francesca; Lauretani, Fulvio; Bandinelli, Stefania; Semba, Richard D.; Bartali, Benedetta; Cherubini, Antonio; Cappola, Anne R.; Ceda, Gian Paolo; Ferrucci, Luigi

    2015-01-01

    Background. In vitro evidence suggests anti-estrogenic properties for retinol and carotenoids, supporting a chemo-preventive role of these phytochemicals in estrogen-dependent cancers. During aging there are significant reductions in retinol and carotenoid concentrations, whereas estradiol levels decline during menopause and progressively increase from the age of 65. We aimed to investigate the hypothesis of a potential relationship between circulating levels of retinol, carotenoids, and estradiol (E2) in a cohort of late post-menopausal women. Methods. We examined 512 women ≥ 65 years from the InCHIANTI study. Retinol, α-caroten, β-caroten, β-criptoxantin, lutein, zeaxanthin, and lycopene levels were assayed at enrollment (1998–2000) by High-Performance Liquid Chromatography. Estradiol and testosterone (T) levels were assessed by Radioimmunometry (RIA) and testosterone-to-estradiol ratio (T/E2), as a proxy of aromatase activity, was also calculated. General linear models adjusted for age (Model 1) and further adjusted for other confounders including Body Mass Index (BMI) BMI, smoking, intake of energy, lipids, and vitamin A; C-Reactive Protein, insulin, total cholesterol, liver function, and testosterone (Model 2) were used to investigate the relationship between retinol, carotenoids, and E2 levels. To address the independent relationship between carotenoids and E2 levels, factors significantly associated with E2 in Model 2 were also included in a fully adjusted Model 3. Results. After adjustment for age, α-carotene (β ± SE = −0.01 ± 0.004, p = 0.02) and β-carotene (β ± SE = −0.07 ± 0.02, p = 0.0007) were significantly and inversely associated with E2 levels. α-Carotene was also significantly and positively associated with T/E2 ratio (β ± SE = 0.07 ± 0.03, p = 0.01). After adjustment for other confounders (Model 2), the inverse relationship between α-carotene (β ± SE = −1.59 ± 0.61, p = 0.01), β-carotene (β ± SE = −0.29 ± 0.08, p

  15. Detection of estradiol-17β during a mass coral spawn

    NASA Astrophysics Data System (ADS)

    Atkinson, S.; Atkinson, M. J.

    1992-04-01

    The steroid estradiol-17β (E2) is associated with female gametogenesis in all vertebrates and many invertebrates. This is the first report of estrogens in scleractinian corals. Seawater and egg slicks were collected during a mass coral spawn at Ningaloo reef, Western Australia for the measurement of total phosphate (TP) and E2. Total P in the water column increased 600 times, from 0.5μM to 300μM. Concentrations of E2 increased nearly 8 fold during the spawn, from 55 to 420 pg/100 ml seawater. Coral eggs collected from egg slicks contained 368±40 pg E2/g dry wt of eggs. Estrogen may be a key hormone in a simple endocrine system of scleractinian corals that synchronizes growth and development of coral oocytes. Its potential role in triggering spawning via chemical messengers in the water column warrants further research.

  16. Behavioral effects of electric and magnetic fields. Final report, January 1, 1985--March 31, 1991

    SciTech Connect

    Laties, V.G.

    1992-04-01

    Two set of behavioral studies were conducted. (1) Electric field: Three procedures were used to determine how aversive a 100 kV/m 60-Hz electric field is for the rat. Each of the procedures enabled rats to respond in order to reduce exposure to the field. The rats did reduce exposure slightly with one, but not with the other two, whereas they reduced their exposure to moderate illumination in all three procedures. The results show that while the procedures were appropriate for assessing stimulus aversiveness, 100 kV/m is not a generally aversive stimulus for the rat. (2) Magnetic Field: Thomas, Schrot and Liboff [Bioelectromagnetics: 7: 349--357 (1986)] reported that immediately after exposure for 30 min to a horizontal 60-Hz, 5 {times} 10{sup {minus}5}T field combined with a total static field of 2.61 {times} 10{sup {minus}5}T, the rate of lever pressing by rats increased during the DRL component of a multiple fixed ratio, DRL schedule of food reinforcement. This project failed to confirm those observations in an experiment that duplicated the behavioral baseline and the magnetic field exposure conditions, with the exception that the total DC vector was greater in these Rochester experiments than it was in Thomas et al, which was done in Bethesda, MD.

  17. Estradiol, SHBG and leptin interplay with food craving and intake across the menstrual cycle.

    PubMed

    Krishnan, Sridevi; Tryon, Rebecca R; Horn, William F; Welch, Lucas; Keim, Nancy L

    2016-10-15

    To understand the association between ovarian hormones, non-acute satiety hormones and craving calorie dense foods in the luteal phase. 17 premenopausal women, mean age 23.2 y, mean BMI 22.4kg/m(2) with regular menstrual cycles were studied during late follicular (FP) and luteal phases (LP). Estradiol, progesterone, DHEAS, SHBG, insulin and leptin, were measured in fasting samples. The validated Food Craving Inventory was used to record the types of foods volunteers habitually ate - rich in fat, carbohydrate or sweet taste, as well as craved during the LP of their menstrual cycle. Estradiol was inversely associated with leptin in FP (r=-0.62, p=0.01). Leptin was inversely associated with habitual intake of sweet foods, in both phases (FP: r=-0.64, p=0.01; LP: r=-0.63, p=0.01). SHBG in LP was positively associated with craving sweet and carbohydrate rich foods. Hierarchical cluster analysis revealed two groups of women, one with high estradiol, high estradiol/leptin ratio, high sweet and carbohydrate cravings (p<0.05); the other group had lower estradiol, lower estradiol/leptin ratio, and reported less craving. The estradiol-leptin axis may be a determinant of luteal phase craving and habitual food intake in menstruating women. NCT01407692. Published by Elsevier Inc.

  18. Complication of a 2-mg estradiol vaginal ring: fibrotic vaginal adhesion.

    PubMed

    Pratts, Meghan E; Shen, Wen

    2014-11-01

    This work aims to review a novel case of a retained 2-mg estradiol vaginal ring used to treat postmenopausal urogenital atrophy. The ring was found adhered to the posterior fornix by a fibrotic band. This is the first reported case in the medical literature. We describe the case of a postmenopausal woman experiencing symptoms of urogenital atrophy. Factors predisposing her to this complication (such as inconsistent use of other forms of vaginal estradiol, initial incorrect use of the ring with two rings in place, and subsequent vaginal stenosis and irritation requiring vaginal dilator therapy at one point in her treatment course) were analyzed. A review of the medical literature was performed to examine the safety profile of estradiol vaginal rings used to treat urogenital atrophy and to investigate the incidence of complications. Two-milligram estradiol vaginal rings treat symptoms of urogenital atrophy by delivering a constant supply of estradiol to the vaginal epithelium. The ring has been shown to be as safe and effective as other forms of vaginal estrogen. Vaginal irritation is a known complication of 2-mg estradiol vaginal rings and other vaginal implants; however, none of the randomized controlled trials that have compared the ring to other vaginal estrogen forms have reported adherence of the ring to the vaginal epithelium. Providers should be aware of the possibility of ring adherence to the vaginal epithelium and should exercise caution in using the 2-mg estradiol vaginal ring in women with significant vaginal stenosis or irritation.

  19. Serum testosterone and estradiol 17-beta concentrations in 15 dogs with perineal hernia.

    PubMed

    Mann, F A; Boothe, H W; Amoss, M S; Tangner, C H; Puglisi, T A; Hobson, H P

    1989-06-01

    Serum testosterone and estradiol 17-beta concentrations, and serum testosterone-to-estradiol ratio were evaluated in 15 dogs (greater than or equal to 5 years old) with perineal hernia (9 sexually intact males and 6 castrated males) and in 9 clinically normal sexually intact male dogs greater than or equal to 5 years old. There was no significant difference in serum testosterone-to-estradiol ratio between sexually intact male dogs with perineal hernia and clinically normal sexually intact male dogs. In castrated dogs with perineal hernia, serum testosterone concentration and testosterone-to-estradiol ratio were significantly (P less than 0.05) lower, compared with those values in sexually intact dogs with perineal hernia and in clinically normal sexually intact male dogs. There was no significant difference in serum estradiol 17-beta concentration among sexually intact male dogs with perineal hernia, castrated dogs with perineal hernia, and clinically normal sexually intact male dogs. Serum testosterone and estradiol 17-beta concentrations in dogs with perineal hernia did not differ from those values in clinically normal male dogs of the same age. Castration cannot be recommended for the treatment of perineal hernia unless a castration-responsive contributing factor such as prostatomegaly is identified, unless the pelvic diaphragm of dogs with perineal hernia has high sensitivity to normal or low serum testosterone and estradiol 17-beta concentrations, or unless there is documentation that other androgens and/or estrogens are involved.

  20. Role of estradiol in cortisol-induced reduction of luteinizing hormone pulse frequency.

    PubMed

    Oakley, Amy E; Breen, Kellie M; Tilbrook, Alan J; Wagenmaker, Elizabeth R; Karsch, Fred J

    2009-06-01

    Precise control of pulsatile GnRH and LH release is imperative to ovarian cyclicity but is vulnerable to environmental perturbations, like stress. In sheep, a sustained (29 h) increase in plasma cortisol to a level observed during stress profoundly reduces GnRH pulse frequency in ovariectomized ewes treated with ovarian steroids, whereas shorter infusion (6 h) is ineffective in the absence of ovarian hormones. This study first determined whether the ovarian steroid milieu or duration of exposure is the relevant factor in determining whether cortisol reduces LH pulse frequency. Prolonged (29 h) cortisol infusion did not lower LH pulse frequency in ovariectomized ewes deprived of ovarian hormones, but it did so in ovariectomized ewes treated with estradiol and progesterone to create an artificial estrous cycle, implicating ovarian steroids as the critical factor. Importantly, this effect of cortisol was more pronounced after the simulated preovulatory estradiol rise of the artificial follicular phase. The second experiment examined which component of the ovarian steroid milieu enables cortisol to reduce LH pulse frequency in the artificial follicular phase: prior exposure to progesterone in the luteal phase, low early follicular phase estradiol levels, or the preovulatory estradiol rise. Basal estradiol enabled cortisol to decrease LH pulse frequency, but the response was potentiated by the estradiol rise. These findings lead to the conclusion that ovarian steroids, particularly estradiol, enable cortisol to inhibit LH pulse frequency. Moreover, the results provide new insight into the means by which gonadal steroids, and possibly reproductive status, modulate neuroendocrine responses to stress.

  1. Context-specific effects of estradiol on spatial learning and memory in the zebra finch.

    PubMed

    Rensel, M A; Salwiczek, L; Roth, J; Schlinger, B A

    2013-02-01

    Estradiol is known to impact cognitive function including spatial learning and memory, with studies focused largely on rodent models. Estrogens can be produced peripherally or centrally as neuroestrogens, and the specific role for neuroestrogens in memory processes remains unresolved. Many songbirds possess remarkable spatial memory capabilities and also express the estrogen synthetic enzyme aromatase abundantly in the hippocampus, suggesting that locally-produced estrogens may promote the acquisition or retrieval of spatial memories in these birds. We examined the effect of estradiol on spatial memory in three contexts in the zebra finch: retrieval after discrimination training, retrieval after familiarization but without discrimination training, and memory acquisition, using a combination of estradiol implants and oral dosing with the aromatase inhibitor fadrozole (FAD). Retrieval of spatial memory in both contexts was impaired when estradiol production was blocked. However, spatial memory acquisition was enhanced when estradiol production was inhibited whereas estradiol replacement impaired acquisition. These results provide evidence for a context-specific role of estradiol in songbird spatial memory, results that find accord with some mammalian studies but have not yet been observed in birds.

  2. Effects of estradiol on the thermoneutral zone and core temperature in ovariectomized rats.

    PubMed

    Dacks, Penny A; Rance, Naomi E

    2010-03-01

    Hot flushes represent a disorder of central thermoregulation characterized by the episodic activation of heat loss mechanisms. Although flushes are associated with estrogen withdrawal, there is little understanding of the effects of estrogen on thermoregulation in any species. It has been proposed that hormone withdrawal increases the sensitivity of hypothalamic neural pathways that control heat dissipation effectors. If so, we predicted that ovariectomized rats without estradiol treatment would activate tail skin vasodilatation (a major heat loss effector) at lower ambient temperatures and thereby lower the thermoneutral zone. The thermoneutral zone, defined as the range of ambient temperatures in which thermoregulation is achieved only by sensible (dry) heat loss, was evaluated based on properties of skin vasomotion. Core and tail skin temperatures were recorded in ovariectomized rats (with and without estradiol-17beta) exposed to ambient temperatures from 13 to 34 C in an environmental chamber. Rats without estradiol exhibited increased skin vasodilatation and a shift in the thermoneutral zone to lower ambient temperatures. Moreover, the ambient temperature threshold for skin vasodilatation was significantly lower in rats without estradiol treatment. At most ambient temperatures, average core temperature was unaffected by estradiol. However, at ambient temperatures of 32.5 C and above, untreated ovariectomized rats exhibited higher core temperatures compared with estradiol-treated rats. Thus, estradiol-17beta treatment enhanced the maintenance of core temperature during heat exposure. These findings support the hypothesis that estrogen withdrawal increases the sensitivity of thermoregulatory neural pathways and modifies the activation of heat loss mechanisms.

  3. Estradiol and progesterone influence on influenza infection and immune response in a mouse model.

    PubMed

    Davis, Sarah M; Sweet, Leigh M; Oppenheimer, Karen H; Suratt, Benjamin T; Phillippe, Mark

    2017-10-01

    Influenza infection severity may be mediated by estradiol and/or progesterone. An exploratory study was designed to evaluate 17-β-estradiol and progesterone on influenza infection and examine immune-mediated response in a mouse model. Inoculation with placebo or mouse-adapted H1N1 influenza virus occurred. Treatment groups included 17-β-estradiol, progesterone, ovariectomy, and pregnancy. Mice were assessed for morbidity and mortality. Toll-like receptor gene studies and airspace cell differentials were performed. Onset of morbidity was earlier and morbidity duration greater for progesterone. Absence of morbidity/mortality and overall survival was greater for 17-β-estradiol. Airspace cell differentials suggest improved immune cell recruitment for 17-β-estradiol. Pregnant mouse data demonstrate significant mortality during the period of increased progesterone. Select immune cell markers demonstrate patterns of regulation that may promote proper immune response to influenza infection for 17-β-estradiol. Estradiol may play a protective and progesterone a detrimental role in the pathophysiology of influenza infection. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Estradiol decreases cortical reactive astrogliosis after brain injury by a mechanism involving cannabinoid receptors.

    PubMed

    López Rodríguez, Ana Belén; Mateos Vicente, Beatriz; Romero-Zerbo, Silvana Y; Rodriguez-Rodriguez, Noé; Bellini, María José; Rodriguez de Fonseca, Fernando; Bermudez-Silva, Francisco Javier; Azcoitia, Iñigo; Garcia-Segura, Luis M; Viveros, María-Paz

    2011-09-01

    The neuroactive steroid estradiol reduces reactive astroglia after brain injury by mechanisms similar to those involved in the regulation of reactive gliosis by endocannabinoids. In this study, we have explored whether cannabinoid receptors are involved in the effects of estradiol on reactive astroglia. To test this hypothesis, the effects of estradiol, the cannabinoid CB1 antagonist/inverse agonist AM251, and the cannabinoid CB2 antagonist/inverse agonist AM630 were assessed in the cerebral cortex of male rats after a stab wound brain injury. Estradiol reduced the number of vimentin immunoreactive astrocytes and the number of glial fibrillary acidic protein immunoreactive astrocytes in the proximity of the wound. The effect of estradiol was significantly inhibited by the administration of either CB1 or CB2 receptor antagonists. The effect of estradiol may be in part mediated by alterations in endocannabinoid signaling because the hormone increased in the injured cerebral cortex the messenger RNA levels of CB2 receptors and of some of the enzymes involved in the synthesis and metabolism of endocannabinoids. These findings suggest that estradiol may decrease reactive astroglia in the injured brain by regulating the activity of the endocannabinoid system.

  5. Associations of estradiol levels and genetic polymorphisms of inflammatory genes with the risk of ischemic stroke.

    PubMed

    Hsieh, Yi-Chen; Hsieh, Fang-I; Chen, Yih-Ru; Hu, Chaur-Jong; Jeng, Jiann-Shing; Tang, Sung-Chun; Chi, Nai-Fang; Lin, Huey-Juan; Lien, Li-Ming; Peng, Giia-Sheun; Chiou, Hung-Yi

    2017-03-28

    Estrogen plays an important role as an anti-inflammatory and neuroprotective agent in ischemic stroke. In this study, we analyzed the effect of a polygenic risk score (PRS) constructed using inflammatory genes and estradiol levels on the risk of ischemic stroke. This case-control study was conducted with 624 ischemic stroke patients and 624 age- and gender-matched controls. The PRS estimated the polygenic contribution of inflammatory genes from ischemic stroke susceptibility loci. Estradiol levels were measured using a radioimmunoassay. High and low estradiol levels were defined according to the log-transformed median estradiol levels in female and male controls. Subjects in the fourth quartile of the PRS had a significant 1.57-fold risk of ischemic stroke (95% confidence interval [CI], 1.12 ~ 2.19), after adjusting for covariates compared to individuals in the lowest quartile. Compared to individuals with high estradiol levels and a low PRS as the reference group, those exposed to low estradiol levels and a high PRS had an increased risk of ischemic stroke (odds ratio, 3.35; 95% CI, 1.79 ~ 6.28). Similar results were also observed in males when the analysis was stratified by gender. Our data suggest that the PRS can be useful in evaluating a high risk of ischemic stroke among patients, especially those exposed to low estradiol levels.

  6. Influence of agricultural antibiotics and 17beta-estradiol on the microbial community of soil.

    PubMed

    Chun, Soul; Lee, Jaehoon; Radosevich, Mark; White, David C; Geyer, Roland

    2006-01-01

    Agricultural pharmaceuticals are a major environmental concern because of their hazardous effects on human and wildlife. This study analyzed phospholipid ester-linked fatty acids (PLFAs) and quinones to investigate the effects of a steroid (17beta-estradiol) and agricultural antibiotics (chlortetracycline and tylosin) on soil microbes in the laboratory. Two different types of soil were used: Sequatchie loam (0.8% organic matter) and LaDelle silt loam (9.2% organic matter). The soils were spiked with 17beta-estradiol and antibiotics, alone or in combination. In Sequatchie loam, 17beta-estradiol significantly increased the microbial biomass, especially the biomarkers for beta proteobacteria (16:1omega7c, 18:1omega7c, Cy17:0, and UQ-8). The coexistence of antibiotics decreased the stimulatory effect of 17beta-estradiol on the microbial community. In LaDelle silt loam, there were no significant differences in total microbial biomass and their microbial community structure among the treatments. Overall, 17beta-estradiol changed the microbial community of soil and the presence of antibiotics nullified the effect of 17beta-estradiol. However, the effects of 17beta-estradiol and antibiotics on soil microbes were sensitive to the soil properties, as seen in the LaDelle silt loam.

  7. Estradiol enhances the acquisition of lithium chloride-induced conditioned taste aversion in castrated male rats.

    PubMed

    Lin, Shih-Fan; Tsai, Yuan-Feen; Tai, Mei-Yun; Yeh, Kuei-Ying

    2015-10-01

    The present study examined the effects of short-term treatment with ovarian hormones on the acquisition of conditioned taste aversion (CTA). Adult male rats were castrated and randomly divided into LiCl- and saline-treated groups. Nineteen days after castration, all of the animals were subjected to 23.5-h daily water deprivation for seven successive days (day 1 to day 7). On the conditioning day (day 8), the rats received either a 4 ml/kg of 0.15 M LiCl or the same dose of saline injection immediately after administration of a 2 % sucrose solution during the 30-min water session. Starting from day 6, rats in both groups received one of the following treatments: daily subcutaneous injection of (1) estradiol alone (30 μg/kg; estradiol benzoate (E) group), (2) estradiol plus progesterone (500 μg; E + progesterone (P) group), or (3) olive oil. From day 9 to day 11, all of the rats were given daily two-bottle preference tests during the 30-min fluid session. The estradiol and estradiol plus progesterone treatments in the LiCl groups resulted in significantly lower preference scores for the sucrose solution compared with the olive oil treatment groups, but no difference in preference score was seen between these two groups. These results indicate that both the estradiol and estradiol plus progesterone treatments in the LiCl groups enhanced the acquisition of CTA learning and suggest that estradiol affects the acquisition of CTA mediated by an activational effect in male rats, whereas progesterone treatment does not influence the effects of estradiol on the acquisition of CTA.

  8. 17beta-Estradiol inhibits cytokine induction of the human E-selectin promoter.

    PubMed

    Tyree, Curtis M; Zou, Aihua; Allegretto, Elizabeth A

    2002-03-01

    Estradiol has been shown to decrease levels of the cell adhesion molecule E-selectin in cultured cells and in women on hormone replacement therapy. We set out to determine if the mechanism of estradiol action on E-selectin is at the level of its promoter. It was found that estradiol repressed the cytokine-stimulated induction of luciferase activity driven by the human E-selectin promoter in a reporter plasmid (hE-sel-LUC) in co-transfected human hepatoma cells (Hep G2) and human umbilical cord endothelial cells (ECV-304). Repression by estradiol was dependent on the presence of transfected estrogen receptor (ER) alpha or beta expression vectors. The ER antagonist ICI-182,780 blocked the repression by estradiol, confirming the receptor-dependence of the effect. The intact DNA-binding domain of ERalpha was required for estradiol repression of the cytokine-induced stimulation of the promoter in each cell line as demonstrated by the inability of an ER construct with two point mutations in the DNA-binding domain to inhibit reporter activity. Mutation of the NFK-B site at -94 to -85 within the E-selectin promoter led to less stimulation of hE-sel-LUC by interleukin one beta (IL-1beta). Estradiol did not inhibit this IL-1beta stimulated luciferase activity, indicating that the NFK-B site is necessary for ER-mediated inhibition of this promoter. Mutation of the AP-1 site at -500 to -494 within the E-selectin promoter had no effect on the ability of IL-1beta to stimulate its transcription, and estradiol repressed this activation in an ER-dependent manner with identical efficacy and potency in comparison with the wild-type promoter. Therefore, the E-selectin promoter is down-regulated by estradiol working through either ERalpha or ERbeta and requires the NFK-B site at -94 to -85 within the promoter.

  9. Estradiol enhances the acquisition of lithium chloride-induced conditioned taste aversion in castrated male rats

    NASA Astrophysics Data System (ADS)

    Lin, Shih-Fan; Tsai, Yuan-Feen; Tai, Mei-Yun; Yeh, Kuei-Ying

    2015-10-01

    The present study examined the effects of short-term treatment with ovarian hormones on the acquisition of conditioned taste aversion (CTA). Adult male rats were castrated and randomly divided into LiCl- and saline-treated groups. Nineteen days after castration, all of the animals were subjected to 23.5-h daily water deprivation for seven successive days (day 1 to day 7). On the conditioning day (day 8), the rats received either a 4 ml/kg of 0.15 M LiCl or the same dose of saline injection immediately after administration of a 2 % sucrose solution during the 30-min water session. Starting from day 6, rats in both groups received one of the following treatments: daily subcutaneous injection of (1) estradiol alone (30 μg/kg; estradiol benzoate (E) group), (2) estradiol plus progesterone (500 μg; E + progesterone (P) group), or (3) olive oil. From day 9 to day 11, all of the rats were given daily two-bottle preference tests during the 30-min fluid session. The estradiol and estradiol plus progesterone treatments in the LiCl groups resulted in significantly lower preference scores for the sucrose solution compared with the olive oil treatment groups, but no difference in preference score was seen between these two groups. These results indicate that both the estradiol and estradiol plus progesterone treatments in the LiCl groups enhanced the acquisition of CTA learning and suggest that estradiol affects the acquisition of CTA mediated by an activational effect in male rats, whereas progesterone treatment does not influence the effects of estradiol on the acquisition of CTA.

  10. De novo synthesized estradiol protects against methylmercury-induced neurotoxicity in cultured rat hippocampal slices.

    PubMed

    Yamazaki, Takeshi; Yamamoto, Megumi; Ishihara, Yasuhiro; Komatsu, Shota; Munetsuna, Eiji; Onizaki, Masahiro; Ishida, Atsuhiko; Kawato, Suguru; Mukuda, Takao

    2013-01-01

    Estrogen, a class of female sex steroids, is neuroprotective. Estrogen is synthesized in specific areas of the brain. There is a possibility that the de novo synthesized estrogen exerts protective effect in brain, although direct evidence for the neuroprotective function of brain-synthesized estrogen has not been clearly demonstrated. Methylmercury (MeHg) is a neurotoxin that induces neuronal degeneration in the central nervous system. The neurotoxicity of MeHg is region-specific, and the molecular mechanisms for the selective neurotoxicity are not well defined. In this study, the protective effect of de novo synthesized 17β-estradiol on MeHg-induced neurotoxicity in rat hippocampus was examined. Neurotoxic effect of MeHg on hippocampal organotypic slice culture was quantified by propidium iodide fluorescence imaging. Twenty-four-hour treatment of the slices with MeHg caused cell death in a dose-dependent manner. The toxicity of MeHg was attenuated by pre-treatment with exogenously added estradiol. The slices de novo synthesized estradiol. The estradiol synthesis was not affected by treatment with 1 µM MeHg. The toxicity of MeHg was enhanced by inhibition of de novo estradiol synthesis, and the enhancement of toxicity was recovered by the addition of exogenous estradiol. The neuroprotective effect of estradiol was inhibited by an estrogen receptor (ER) antagonist, and mimicked by pre-treatment of the slices with agonists for ERα and ERβ, indicating the neuroprotective effect was mediated by ERs. Hippocampus de novo synthesized estradiol protected hippocampal cells from MeHg-induced neurotoxicity via ERα- and ERβ-mediated pathways. The self-protective function of de novo synthesized estradiol might be one of the possible mechanisms for the selective sensitivity of the brain to MeHg toxicity.

  11. De Novo Synthesized Estradiol Protects against Methylmercury-Induced Neurotoxicity in Cultured Rat Hippocampal Slices

    PubMed Central

    Ishihara, Yasuhiro; Komatsu, Shota; Munetsuna, Eiji; Onizaki, Masahiro; Ishida, Atsuhiko; Kawato, Suguru; Mukuda, Takao

    2013-01-01

    Background Estrogen, a class of female sex steroids, is neuroprotective. Estrogen is synthesized in specific areas of the brain. There is a possibility that the de novo synthesized estrogen exerts protective effect in brain, although direct evidence for the neuroprotective function of brain-synthesized estrogen has not been clearly demonstrated. Methylmercury (MeHg) is a neurotoxin that induces neuronal degeneration in the central nervous system. The neurotoxicity of MeHg is region-specific, and the molecular mechanisms for the selective neurotoxicity are not well defined. In this study, the protective effect of de novo synthesized 17β-estradiol on MeHg-induced neurotoxicity in rat hippocampus was examined. Methodology/Principal Findings Neurotoxic effect of MeHg on hippocampal organotypic slice culture was quantified by propidium iodide fluorescence imaging. Twenty-four-hour treatment of the slices with MeHg caused cell death in a dose-dependent manner. The toxicity of MeHg was attenuated by pre-treatment with exogenously added estradiol. The slices de novo synthesized estradiol. The estradiol synthesis was not affected by treatment with 1 µM MeHg. The toxicity of MeHg was enhanced by inhibition of de novo estradiol synthesis, and the enhancement of toxicity was recovered by the addition of exogenous estradiol. The neuroprotective effect of estradiol was inhibited by an estrogen receptor (ER) antagonist, and mimicked by pre-treatment of the slices with agonists for ERα and ERβ, indicating the neuroprotective effect was mediated by ERs. Conclusions/Significance Hippocampus de novo synthesized estradiol protected hippocampal cells from MeHg-induced neurotoxicity via ERα- and ERβ-mediated pathways. The self-protective function of de novo synthesized estradiol might be one of the possible mechanisms for the selective sensitivity of the brain to MeHg toxicity. PMID:23405170

  12. Membrane-Initiated Estradiol Signaling Induces Spinogenesis Required for Female Sexual Receptivity

    PubMed Central

    Christensen, Amy; Dewing, Phoebe

    2011-01-01

    Estrogens have profound actions on the structure of the nervous system during development and in adulthood. One of the signature actions of estradiol is to alter the morphology of neural processes. In the hippocampus, estradiol modulates spines and cellular excitability that affect cognitive behaviors. In the hypothalamus, estradiol increases spine density in mediobasal hypothalamic nuclei that regulate reproduction. The hypothalamic arcuate nucleus (ARH), an important site for modulation of female sexual receptivity, has a sexual dimorphism in dendritic spine density that favors females. In the present study, we used both β-actin immunostaining and Golgi staining to visualize estradiol-induced changes in spine density in Long–Evans rats. Golgi impregnation was used to visualize spine shape, and then β-actin immunoreactivity was used as a semiquantitative measure of spine plasticity since actin forms the core of dendritic spines. At 4 h after estradiol treatment, both β-actin immunofluorescence and filopodial spines were increased (from 70.57 ± 1.09% to 78.01 ± 1.05%, p < 0.05). Disruption of estradiol-induced β-actin polymerization with cytochalasin D attenuated lordosis behavior, indicating the importance of estradiol-mediated spinogenesis for female sexual receptivity (81.43 ± 7.05 to 35.00 ± 11.76, p < 0.05). Deactivation of cofilin, an actin depolymerizing factor is required for spinogenesis. Membrane-initiated estradiol signaling involving the metabotropic glutamate receptor 1a was responsible for the phosphorylation and thereby deactivation of cofilin. These data demonstrate that estradiol-induced spinogenesis in the ARH is an important cellular mechanism for the regulation of female sexual behavior. PMID:22131419

  13. Low-dosage micronized 17 beta-estradiol prevents bone loss in postmenopausal women

    NASA Technical Reports Server (NTRS)

    Ettinger, B.; Genant, H. K.; Steiger, P.; Madvig, P.

    1992-01-01

    With the use of a double-blind, randomized, dose-ranging design, we tested during an 18-month period the degree of protection against postmenopausal bone loss afforded by micronized 17 beta-estradiol in dosages of 0.5, 1.0, and 2.0 mg. All subjects received supplementation to ensure a minimum of 1500 mg calcium daily. Fifty-one subjects completed at least 1 year of follow-up bone density measurements by quantitative computed tomography and by single- and dual-photon absorptiometry. In the placebo group spinal trabecular bone density decreased 4.9% annually (p less than 0.001), whereas in those taking micronized 17 beta-estradiol bone density tended to increase (annual increases of 0.3% in the 0.5 mg micronized 17 beta-estradiol group, 1.8% in the 1.0 mg micronized 17 beta-estradiol group, and 2.5% in the 2.0 mg micronized 17 beta-estradiol group). After completing the double-blind phase, 41 subjects completed an additional 18 months of follow-up while taking 1.0 mg micronized 17 beta-estradiol. During this time one third of the subjects were randomly assigned to discontinue calcium supplements. Among those who previously received placebo, trabecular bone density increased 4.3% annually, whereas among those who had used micronized 17 beta-estradiol, trabecular bone density response was inversely related to the dosage previously used. Additionally and independently, the level of calcium intake showed a statistically significant correlation with the change in spinal trabecular bone density (r = 0.37, p = 0.02). We conclude that micronized 17 beta-estradiol has a continuous skeletal dose-response effect in the range of 0.5 to 2.0 mg and that calcium intake positively modifies the skeletal response to 1.0 mg micronized 17 beta-estradiol.

  14. Increased Estradiol and Improved Sleep, But Not Hot Flashes, Predict Enhanced Mood during the Menopausal Transition

    PubMed Central

    Petrillo, Laura Fagioli; Koukopoulos, Alexia; Viguera, Adele C.; Hirschberg, April; Nonacs, Ruta; Somley, Brittny; Pasciullo, Erica; White, David P.; Hall, Janet E.; Cohen, Lee S.

    2011-01-01

    Background: The antidepressant effect of estrogen in women undergoing the menopause transition is hypothesized to be mediated by central nervous system effects of increasing estradiol on mood or through a pathway involving suppression of hot flashes and associated sleep disturbance. Estrogen therapy (ET) and the hypnotic agent zolpidem were selected as interventions in a three-arm, double-blind, placebo-controlled trial to distinguish the effects of estradiol, sleep, and hot flashes on depression. Methods: Women with depressive disorders, hot flashes, and sleep disturbance were randomly assigned to transdermal 17β-estradiol 0.05 mg/d, zolpidem 10 mg/d, or placebo for 8 wk. Changes in serum estradiol, perceived sleep quality, objectively measured sleep, and hot flashes were examined as predictors of depression improvement [Montgomery-Åsberg Depression Rating Scale (MADRS)] using multivariate linear regression. Results: Seventy-two peri/postmenopausal women with depression disorders were randomized to 17β-estradiol (n = 27), zolpidem (n = 31), or placebo (n = 14). There was no significant difference between groups in depression improvement (overall MADRS decrease 11.8 ± 8.6). Increasing estradiol (P = 0.009) and improved sleep quality (P < 0.001) predicted improved mood in adjusted models but reduced hot flashes (P = 0.99) did not. Post hoc subgroup analyses revealed that the therapeutic effect of increasing estradiol levels on mood was seen in perimenopausal (P = 0.009), but not postmenopausal, women. Conclusions: For women with menopause-associated depression, improvement in depression is predicted by improved sleep, and among perimenopausal women, by increasing estradiol levels. These results suggest that changes in estradiol and sleep quality, rather than hot flashes, mediate depression during the menopause transition. Therapies targeting insomnia may be valuable in treating menopause-associated depression. PMID:21525161

  15. Low-dosage micronized 17 beta-estradiol prevents bone loss in postmenopausal women

    NASA Technical Reports Server (NTRS)

    Ettinger, B.; Genant, H. K.; Steiger, P.; Madvig, P.

    1992-01-01

    With the use of a double-blind, randomized, dose-ranging design, we tested during an 18-month period the degree of protection against postmenopausal bone loss afforded by micronized 17 beta-estradiol in dosages of 0.5, 1.0, and 2.0 mg. All subjects received supplementation to ensure a minimum of 1500 mg calcium daily. Fifty-one subjects completed at least 1 year of follow-up bone density measurements by quantitative computed tomography and by single- and dual-photon absorptiometry. In the placebo group spinal trabecular bone density decreased 4.9% annually (p less than 0.001), whereas in those taking micronized 17 beta-estradiol bone density tended to increase (annual increases of 0.3% in the 0.5 mg micronized 17 beta-estradiol group, 1.8% in the 1.0 mg micronized 17 beta-estradiol group, and 2.5% in the 2.0 mg micronized 17 beta-estradiol group). After completing the double-blind phase, 41 subjects completed an additional 18 months of follow-up while taking 1.0 mg micronized 17 beta-estradiol. During this time one third of the subjects were randomly assigned to discontinue calcium supplements. Among those who previously received placebo, trabecular bone density increased 4.3% annually, whereas among those who had used micronized 17 beta-estradiol, trabecular bone density response was inversely related to the dosage previously used. Additionally and independently, the level of calcium intake showed a statistically significant correlation with the change in spinal trabecular bone density (r = 0.37, p = 0.02). We conclude that micronized 17 beta-estradiol has a continuous skeletal dose-response effect in the range of 0.5 to 2.0 mg and that calcium intake positively modifies the skeletal response to 1.0 mg micronized 17 beta-estradiol.

  16. Low doses of estradiol partly inhibit release of GH in sheep without affecting basal levels.

    PubMed

    Hudmon, A; Davenport, G; Coleman, E S; Sartin, J L

    2009-10-01

    Estradiol increases basal growth hormone (GH) concentrations in sheep and cattle. This study sought to determine the effects of estradiol on GH-releasing hormone (GRH)-stimulated GH release in sheep. Growth hormone secretory characteristics, the GH response to GRH, and steady-state GH mRNA concentrations were determined in castrated male lambs treated with 2 different doses of estradiol 17-beta for a 28-d experimental period. Although no differences between treatments in mean GH, basal GH, or GH pulse number were observed after 28 d of estradiol treatment, GH pulse amplitude was greater (P < 0.05) in the 2.00-cm implant-treated animals than in the control and 0.75-cm implant group. The effect of estradiol treatment on GRH-stimulated GH release revealed differences between the control and estradiol-treated animals (P < 0.05). The 15-min GH responses to 0.075 microg/kg hGRH in the control, 0.75-cm, and 2.00-cm implant groups, respectively, were 76 +/- 10, 22.6 +/- 2.1, and 43.6 +/- 15.0 ng/mL. Growth hormone mRNA content was determined for pituitary glands from the different treatment groups, and no differences in steady-state GH mRNA levels were observed. There were no differences in the mean plasma concentrations of IGF-I, cortisol, T(3), or T(4) from weekly samples. Growth hormone release from cultured ovine pituitary cells from control sheep was not affected by estradiol after 72 h or in a subsequent 3-h incubation with estradiol combined with GRH. These data suggest that estradiol has differing actions on basal and GRH-stimulated GH concentrations in plasma, but the increase in pulse amplitude does not represent an increased pituitary sensitivity to GRH.

  17. Environmental magnetic fields inhibit the antiproliferative action of tamoxifen and melatonin in a human breast cancer cell line.

    PubMed

    Harland, J D; Liburdy, R P

    1997-01-01

    We have previously reported that environmental-level magnetic fields (1.2 microT [12 milligauss], 60 Hz) block the growth inhibition of the hormone melatonin (10(-9) M) on MCF-7 human breast cancer cells in vitro. We now report that the same 1.2 microT, 60 Hz magnetic fields significantly block the growth inhibitory action of pharmacological levels of tamoxifen (10(-7) M). In biophysical studies we have taken advantage of Faraday's Law of Current Induction and tested whether the 1.2 microT magnetic field or the associated induced electric field is responsible for this field effect on melatonin and tamoxifen. We observe that the magnetic field component is associated with the field blocking effect on melatonin and tamoxifen function. To our knowledge the tamoxifen studies represent the first experimental evidence for an environmental-level magnetic field modification of drug interaction with human breast cancer cells. Together, these findings provide support to the theory that environmental-level magnetic fields can act to modify the action of a drug or hormone on regulation of cell proliferation. Melatonin and tamoxifen may act through different biological pathways to down-regulate cell growth, and further studies are required to identify a specific biological site of interaction for the 1.2 microT magnetic field.

  18. Biological Detection of Low-Level Electric Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Barnes, Frank S.

    1996-03-01

    This paper will review sources of noise in biological systems including thermal noise, shot noise, 1/f noise, signals generated by the biological system, and the background environment. These noise signals will be examined for a model nerve cell and compared with estimates for the electrical and magnetic signals which are typically generated by our power distribution systems at 60 Hz. A number of mechanisms by which biological systems may be able to extract signals from noise will be described. All of these mechanism require biological system nonlinearities and repetitive signals. The results of computer simulation show that computer models of a neural network can be trained to identify a 60-Hz signal with 97% accuracy at signal-to-noise ratios from 1 to 0.001 using a back propagation algorithm. The number of training runs increases with decreasing signal-to-noise ratio. These results will be discussed in terms of biological results which show that sharks can detect electrical signal levels approaching 10-7 V/m and bees can detect changes in magnetic field levels of 10-9 T. Some recent results from our lab on the effects of ELF magnetic fields on the growth rate of pre T cells will also be presented.

  19. Steroidal affinity labels of the estrogen receptor. 2. 17 alpha-[(Haloacetamido)alkyl]estradiols.

    PubMed

    el Garrouj, D; Aliau, S; Aumelas, A; Borgna, J L

    1995-06-23

    In a previous study, we described affinity labeling of the lamb uterine estrogen receptor by 17 alpha-[(bromoacetoxy)alkyl/alkynyl]estradiols. However, the intrinsic receptor-alkylating activities of these compounds were probably very hampered by their poor hydrolytic stability in estrogen receptor-containing tissue extracts. Therefore, (i) to develop affinity labels of the receptor not susceptible to hydrolysis and (ii) to specify the structural requirements for 17 alpha-electrophilic estradiol derivatives to be potent affinity labels of the receptor, we prepared four 17 alpha-[(haloacetamido)alkyl]estradiols. Three were bromoacetamides differing at the alkyl substituent (methyl, ethyl, or propyl), and the last was an [(iodoacetamido)propyl]estradiol prepared under both nonradioactive and 3H-labeled forms. Although their affinities for the estrogen receptor were very low (from 0.008% to 0.02% that of estradiol), they appeared to be efficient affinity labels of the receptor due to their irreversible inhibition of [3H]estradiol specific binding in lamb uterine cytosol. The effect of the compounds was time-, pH-, and concentration-dependent, with > 50% and > 80% estrogen-binding sites inactivated at 0 degrees C and pH 8.5, for the less active and more active compounds, respectively; the corresponding IC50 values varied from approximately 20 nM to approximately 10 microM. The order of efficiency was [(bromoacetamido)methyl]estradiol < [(bromoacetamido)ethyl]estradiol < [(bromoacetamido)propyl]estradiol < [(iodoacetamido)propyl]estradiol. Affinity labeling was directly demonstrated by ethanol-resistant binding of [3H][(iodoacetamido)propyl]estradiol to the receptor. The irreversible inactivation of the hormone-binding site by the four haloacetamides was prevented by treatment of the cytosol with the thiol-specific reagent methyl methanethiosulfonate, suggesting that the target of these compounds was probably the -SH of cysteines. Negative results obtained with other 17

  20. Mechanism of the Rapid Effect of 17β -Estradiol on Medial Amygdala Neurons

    NASA Astrophysics Data System (ADS)

    Nabekura, Junichi; Oomura, Yutaka; Minami, Taketsugu; Mizuno, Yuji; Fukuda, Atsuo

    1986-07-01

    The mechanism by which sex steroids rapidly modulate the excitability of neurons was investigated by intracellular recording of neurons in rat medial amygdala brain slices. Brief hyperpolarization and increased potassium conductance were produced by 17β - estradiol. This effect persisted after elimination of synaptic input and after suppression of protein synthesis. Thus, 17β -estradiol directly changes the ionic conductance of the postsynaptic membrane of medial amygdala neurons. In addition, a greater proportion of the neurons from females than from males responded to 17β -estradiol.

  1. Estrogenic potencies of resorcylic acid lactones and 17 beta-estradiol in female rats.

    PubMed

    Everett, D J; Perry, C J; Scott, K A; Martin, B W; Terry, M K

    1987-01-01

    Uterotrophic response in sexually immature female rats has been used to rank the relative estrogenic potencies of six resorcylic acid lactones (RALs) and to compare their activities with that of 17 beta-estradiol. On oral administration, the estrogenic potency relative to 17 beta-estradiol is as follows: 7 alpha-zearalenol, 10 times less; zeranol, 150 times less; taleranol, 350 times less; zearalanone, 400 times less; zearalenone, 650 times less; 7 beta-zearalenol, 3500 times less. On subcutaneous administration, zeranol is 500 times less estrogenic than 17 beta-estradiol.

  2. Electromagnetic Fields Associated with Commercial Solar Photovoltaic Electric Power Generating Facilities.

    PubMed

    Tell, R A; Hooper, H C; Sias, G G; Mezei, G; Hung, P; Kavet, R

    2015-01-01

    The southwest region of the United States is expected to experience an expansion of commercial solar photovoltaic generation facilities over the next 25 years. A solar facility converts direct current generated by the solar panels to three-phase 60-Hz power that is fed to the grid. This conversion involves sequential processing of the direct current through an inverter that produces low-voltage three-phase power, which is stepped up to distribution voltage (∼12 kV) through a transformer. This study characterized magnetic and electric fields between the frequencies of 0 Hz and 3 GHz at two facilities operated by the Southern California Edison Company in Porterville, CA and San Bernardino, CA. Static magnetic fields were very small compared to exposure limits established by IEEE and ICNIRP. The highest 60-Hz magnetic fields were measured adjacent to transformers and inverters, and radiofrequency fields from 5-100 kHz were associated with the inverters. The fields measured complied in every case with IEEE controlled and ICNIRP occupational exposure limits. In all cases, electric fields were negligible compared to IEEE and ICNIRP limits across the spectrum measured and when compared to the FCC limits (≥0.3 MHz).

  3. Estradiol reduces anxiety- and depression-like behavior of aged female mice.

    PubMed

    Walf, Alicia A; Frye, Cheryl A

    2010-02-09

    Beneficial effects of the ovarian steroid, 17beta-estradiol (E(2)), for affective behavior have been reported in young individuals, but less is known about the effects of E(2) among older individuals, and the capacity of older individuals to respond to E(2) following its decline. In the present study, the effects of acute E(2) administration to aged mice for anxiety-like and depression-like behaviors were investigated. Intact female C57BL/6 mice (N=18) that were approximately 24 months old were administered vehicle (sesame oil, n=9) or E(2) (10 microg, n=9) subcutaneously 1h prior to behavioral testing. Mice were tested for anxiety-like behavior (open field, elevated plus maze, mirror chamber, light-dark transition task, Vogel conflict task) and depression-like behavior (forced swim task). To assess the role of general motor behavior and coordination in these aged mice, performance in an activity monitor and rotarod task, and total entries made in tasks (open field, elevated plus maze, light-dark transition task) were determined. Mice administered E(2), compared to vehicle, demonstrated anti-anxiety behavior in the open field, mirror chamber, and light-dark transition task, and anti-depressive-like behavior in the forced swim task. E(2) also tended to have anti-anxiety effects in the elevated plus maze and Vogel task compared to vehicle administration, but these effects did not reach statistical significance. E(2) did not alter motor behavior and/or coordination in the activity monitor, open field, or rotarod tasks. Thus, an acute E(2) regimen produced specific anti-anxiety and anti-depressant effects, independent of effects on motor behavior, when administered to aged female C57BL/6 mice.

  4. Estradiol reduces anxiety- and depression-like behavior of aged female mice

    PubMed Central

    Walf, Alicia A.; Frye, Cheryl A.

    2013-01-01

    Beneficial effects of the ovarian steroid, 17β-estradiol (E2), for affective behavior have been reported in young individuals, but less is known about the effects of E2 among older individuals, and the capacity of older individuals to respond to E2 following its decline. In the present study, the effects of acute E2 administration to aged mice for anxiety-like and depression-like behaviors were investigated. Intact female C57BL/6 mice (N=18) that were approximately 24 months old were administered vehicle (sesame oil, n=9) or E2 (10 μg, n=9) subcutaneously 1h prior to behavioral testing. Mice were tested for anxiety-like behavior (open field, elevated plus maze, mirror chamber, light–dark transition task, Vogel conflict task) and depression-like behavior (forced swim task). To assess the role of general motor behavior and coordination in these aged mice, performance in an activity monitor and rotarod task, and total entries made in tasks (open field, elevated plus maze, light–dark transition task) were determined. Mice administered E2, compared to vehicle, demonstrated anti-anxiety behavior in the open field, mirror chamber, and light–dark transition task, and anti-depressive-like behavior in the forced swim task. E2 also tended to have anti-anxiety effects in the elevated plus maze and Vogel task compared to vehicle administration, but these effects did not reach statistical significance. E2 did not alter motor behavior and/or coordination in the activity monitor, open field, or rotarod tasks. Thus, an acute E2 regimen produced specific anti-anxiety and anti-depressant effects, independent of effects on motor behavior, when administered to aged female C57BL/6 mice. PMID:19804793

  5. Variation of lead-induced lethality in estradiol-treated mice

    SciTech Connect

    Hogan, G.R.

    1982-03-01

    Studies were undertaken to test the female sex hormone ..beta..-estradiol for its ability to modify lethality in young adult female and male mice exposed to lead acetate. Mice were injected with ..beta..-estradiol on day -1 and 0, and immediately after the second injection lead acetate was administered at four subgroup dosages ranging from 75 to 600 mg/kg body weight. Control mice were injected with only lead acetate. On day 4, 6, and 8 after Pb, the median lethal dosages (LD/sub 50/s) were calculated from the observed mortality ratios by a method for moving averages. LD/sub 50/ values were considerably lower for the Pb- and ..beta..-estradiol-injected groups than for the controls. Data from these experiments indicate that the ..beta..-estradiol treatments render both female and male mice more vulnerable to the lethal effects of lead acetate.

  6. OOCYTE ENVELOPE PROTEINS AND VITELLOGENIN IN MALE SHEEPHEAD MINNOW EXPOSED TO ESTRADIOL

    EPA Science Inventory

    Oocyte Envelope Proteins and Vitellogenin Expression in Male Sheepshead Minnows Exposed to Estradiol (Abstract). To be presented at the 22nd Annual Meeting of the Society of Environmental Toxicology and Chemistry: Changing Environmental Awareness: Societal Concerns and Scientifi...

  7. COULD ETHINYL ESTRADIOL AFFECT THE POPULATION BIOLOGY OF CUNNER, TAUTOGOLABRUS ADSPERSUS

    EPA Science Inventory

    Endocrine disrupting chemicals in the environment may disturb the population dynamics of wildlife by affecting reproductive output and embryonic development of organisms. This study used a population model to evaluate whether ethinyl estradiol (EE2 could affect cunner Tautogolabr...

  8. Determination of estradiol valerate in pharmaceutical preparations and human serum by flow injection chemiluminescence.

    PubMed

    Liu, Wenwen; Xie, Liangxiao; Liu, Hongshuang; Xu, Shichao; Hu, Bingcheng; Cao, Wei

    2013-01-01

    A novel method for the detection of trace estradiol valerate (EV) in pharmaceutical preparations and human serum was developed by inhibition of luminol chemiluminescence (CL) by estradiol valerate on the zinc deuteroporphyrin (ZnDP)-enhanced luminol-K3 Fe(CN)6 chemiluminescence system. Under optimized experimental conditions, CL intensity and concentration of estradiol valerate had a good linear relationship in the ranges of 8.0 × 10(-8) to 1.0 × 10(-5) g/mL. Detection limit (3σ) was estimated to be 3.5 × 10(-8) g/mL. The proposed method was applied successfully for the determination of estradiol valerate in pharmaceutical preparations and human serum and recoveries were 97.0-105.0% and 95.5-106.0%, respectively. The possible mechanism of the CL system is discussed.

  9. COULD ETHINYL ESTRADIOL AFFECT THE POPULATION BIOLOGY OF CUNNER, TAUTOGOLABRUS ADSPERSUS

    EPA Science Inventory

    Endocrine disrupting chemicals in the environment may disturb the population dynamics of wildlife by affecting reproductive output and embryonic development of organisms. This study used a population model to evaluate whether ethinyl estradiol (EE2 could affect cunner Tautogolabr...

  10. [Chronic administration of estradiol to ovariectomized female Wistar rats causes development of hypoxic pulmonary hypertension].

    PubMed

    Kovaleva, Iu O; Artem'eva, M M; Medvedev, O S; Medvedeva, N A

    2013-01-01

    We have studied the role of female sex hormone estradiol in the development of hypoxic pulmonary arterial hypertension. Previously, it was shown that the development of pulmonary hypertension in Wistar female rats is accompanied by a twofold increase in the estradiol level. Ovariectomy reduces the degree of pulmonary hypertension in these animals. In this work, the effect of various chronic doses of exogenous estradiol (5 and 15 microg/kg per day) on the development of hypoxic pulmonary hypertension in Wistar female rats has been studied. Pulmonary hypertension was induced by exposure to hypobaric hypoxia (10 h a day for 2 weeks) at simulated altitude of 5000 m (O2 concentration reduced to 10%). The administration of estradiol in different doses (5 and 15 microg/kg per day) for 21 day initiated the development of pulmonary hypertension in ovariectomized Wistar female rats.

  11. OOCYTE ENVELOPE PROTEINS AND VITELLOGENIN IN MALE SHEEPHEAD MINNOW EXPOSED TO ESTRADIOL

    EPA Science Inventory

    Oocyte Envelope Proteins and Vitellogenin Expression in Male Sheepshead Minnows Exposed to Estradiol (Abstract). To be presented at the 22nd Annual Meeting of the Society of Environmental Toxicology and Chemistry: Changing Environmental Awareness: Societal Concerns and Scientifi...

  12. Neuroprotective Actions of Estradiol and Novel Estrogen Analogs in Ischemia: Translational Implications

    PubMed Central

    Etgen, Anne M.; Jover-Mengual, Teresa; Suzanne Zukin, R.

    2011-01-01

    This review highlights our investigations into the neuroprotective efficacy of estradiol and other estrogenic agents in a clinically relevant animal model of transient global ischemia, which causes selective, delayed death of hippocampal CA1 neurons and associated cognitive deficits. We find that estradiol rescues a significant number of CA1 pyramidal neurons that would otherwise die in response to global ischemia, and this is true when hormone is provided as a long-term pretreatment at physiological doses or as an acute treatment at the time of reperfusion. In addition to enhancing neuronal survival, both forms of estradiol treatment induce measurable cognitive benefit in young animals. Moreover, estradiol and estrogen analogs that do not bind classical nuclear estrogen receptors retain their neuroprotective efficacy in middle-aged females deprived of ovarian hormones for a prolonged duration (8 weeks). Thus, non-feminizing estrogens may represent a new therapeutic approach for treating the neuronal damage associated with global ischemia. PMID:21163293

  13. Direct measurement of free estradiol in human serum by equilibrium dialysis-liquid chromatography-tandem mass spectrometry and reference intervals of free estradiol in women.

    PubMed

    Ray, Julie A; Kushnir, Mark M; Bunker, Ashley; Rockwood, Alan L; Meikle, A Wayne

    2012-06-14

    Measurement of free estradiol offers a better representation of the bioactive fraction of the hormone. We describe a direct equilibrium dialysis-liquid chromatography-tandem mass spectrometry (ED-LC-MS/MS) method for serum free estradiol. Two hundred fifty microliter aliquots of serum were dialyzed for 22h followed by liquid-liquid extraction and derivatization with dansyl chloride. Free estradiol was measured using LC-MS/MS with an AB SCIEX 5500 mass spectrometer in positive ion and multiple reaction monitoring (MRM) mode. The limits of detection and quantification for free estradiol were 0.25 and 0.5pg/ml (0.9 and 1.8pmol/l) respectively. Total imprecision was less than 10%. Results of method comparison showed 3 times overestimation using indirect methods of measurement. Reference intervals in pre-menopausal women in follicular, mid-cycle, and luteal phases of cycle were <2.4, <3.1 and <2.6pg/ml (8.8, 11.4, 9.5pmol/l) respectively; in post menopausal women the concentrations were ≤0.5pg/ml (1.8pmol/l). ED-LC-MS/MS is a direct method for accurately measuring free estradiol, independent of total estradiol or sex hormone binding globulin concentrations. Imprecision and sensitivity of the method are adequate for clinical diagnostic applications. The degree of variation observed in the method comparison reinforces the relevance of method specific reference ranges. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Estrus synchronization in cattle using estradiol, melengestrol acetate and PGF.

    PubMed

    Kastelic, J P; McCartney, D H; Olson, W O; Barth, A D; Garcia, A; Mapletoft, R J

    1996-11-01

    In Experiment 1, all cattle were fed MGA (0.5 mg/head/d) for 7 d (designated Days 0 to 6) and given PGF on Day 6. One-half were administered estradiol valerate (EV; 5 mg, im) on Day 0. At Location 1, a higher proportion (P < 0.005) of EV-treated heifers were detected in estrus and bred by AI between Days 7 and 13 than control heifers not receiving EV (27 of 33 versus 15 of 32), but the number of pregnancies (12 vs 10) was not significantly different. Eighty-three of 104 EV-treated and 89 of 106 control cows were inseminated, resulting in 50 and 45 pregnancies, respectively (not significant). At Location 2, cattle were similarly treated and exposed to bulls on Days 7 to 49. Fall pregnancy rate was higher (P < 0.015) for EV-treated than control heifers (44 of 48 vs 33 of 46), but was not significantly different for cows (22 of 26 vs 19 of 23). In Experiment 2, estradiol 17beta (E17beta; 5 mg, im) and progesterone (100 mg, im) were administered on Day 0 (instead of EV). In a third group (designated the PGF group), cattle were bred on Days 0 to 6, and PGF was administered on Day 6 to those not yet bred. For 213 cows, the percentage pregnant to a synchronized estrus was greater in the PGF group (72%) than in either the control group treated with MGA (49%; P = 0.005) or the group receiving MGA and E17beta (54%; P < 0.025). Fall pregnancy rates were 91, 89, and 96% for the 213 cows (not significant) and 89, 93, and 98% for 131 heifers (not significant) in the PGF, MGA and E17beta groups, respectively. In cattle without a functional CL, the average diameter of the largest follicle at Day 6 was 1 to 2 mm smaller in the E17beta + MGA group than in the MGA group (difference significant only in cows at Location 1). Combined for both locations, the synchronized pregnancy rate in heifers without a functional CL on Day 6 was higher (P < 0.05) in the E17beta + MGA group than in the MGA group (11 of 21, 52% versus 4 of 20, 20%). Estrogen treatment caused regression of ovarian

  15. Estradiol influences the mechanical properties of human fetal osteoblasts through cytoskeletal changes

    SciTech Connect

    Muthukumaran, Padmalosini; Lim, Chwee Teck; Lee, Taeyong

    2012-07-06

    Highlights: Black-Right-Pointing-Pointer Estradiol induced stiffness changes of osteoblasts were quantified using AFM. Black-Right-Pointing-Pointer Estradiol causes significant decrease in the stiffness of osteoblasts. Black-Right-Pointing-Pointer Decreased stiffness was caused by decreased density of f-actin network. Black-Right-Pointing-Pointer Stiffness changes were not associated with mineralized matrix of osteoblasts. Black-Right-Pointing-Pointer Estradiol increases inherent alkaline phosphatase activity of osteoblasts. -- Abstract: Estrogen is known to have a direct effect on bone forming osteoblasts and bone resorbing osteoclasts. The cellular and molecular effects of estrogen on osteoblasts and osteoblasts-like cells have been extensively studied. However, the effect of estrogen on the mechanical property of osteoblasts has not been studied yet. It is important since mechanical property of the mechanosensory osteoblasts could be pivotal to its functionality in bone remodeling. This is the first study aimed to assess the direct effect of estradiol on the apparent elastic modulus (E{sup Asterisk-Operator }) and corresponding cytoskeletal changes of human fetal osteoblasts (hFOB 1.19). The cells were cultured in either medium alone or medium supplemented with {beta}-estradiol and then subjected to Atomic Force Microscopy indentation (AFM) to determine E{sup Asterisk-Operator }. The underlying changes in cytoskeleton were studied by staining the cells with TRITC-Phalloidin. Following estradiol treatment, the cells were also tested for proliferation, alkaline phosphatase activity and mineralization. With estradiol treatment, E{sup Asterisk-Operator} of osteoblasts significantly decreased by 43-46%. The confocal images showed that the changes in f-actin network observed in estradiol treated cells can give rise to the changes in the stiffness of the cells. Estradiol also increases the inherent alkaline phosphatase activity of the cells. Estradiol induced stiffness

  16. Histologic study of the internal organs of rats chronically exposed to a high-intensity electric field

    SciTech Connect

    Seto, Y.J.; Majeau-Chargois, D.; Lymangrover, J.R.; Dunlap, W.P.; Hsieh, S.T.

    1985-01-01

    The effect of 120-day exposure to a high-intensity (80 kV/m), 60-Hz electric field on histology of selected internal organs of Sprague-Dawley rats was investigated. The organs examined were the pituitary, thymus, heart, lungs, liver, spleen, right and left adrenals, right and left kidneys, and right and left testes. Histological examination of 10-micron tissue sections from randomly selected animals revealed no specific evidence of histopathologic differences between field-exposed and sham-exposed animals at the light microscopic level.

  17. 17β-estradiol in runoff as affected by various poultry litter application strategies.

    PubMed

    Delaune, P B; Moore, P A

    2013-02-01

    Steroidal hormones, which are excreted by all mammalian species, have received increasing attention in recent years due to potential environmental implications. The objective of this study was to evaluate 17β-estradiol concentrations in runoff water from plots receiving poultry litter applications using various management strategies. Treatments included the effects of 1) aluminum sulfate (alum) application rates to poultry litter; 2) time until the first runoff event occurs after poultry litter application; 3) poultry litter application rate; 4) fertilizer type; and 5) litter from birds fed modified diets. Rainfall simulators were used to cause continuous runoff from fertilized plots. Runoff samples were collected and analyzed for 17β-estradiol concentrations. Results showed that increasing alum additions to poultry litter decreased 17β-estradiol concentrations in runoff water. A significant exponential decline in 17β-estradiol runoff was also observed with increasing time until the first runoff event after litter application. Concentrations of 17β-estradiol in runoff water increased with increasing litter application rate and remained above background concentrations after three runoff events at higher application rates. Management practices such as diet modification and selection of fertilizer type were also shown to affect 17β-estradiol concentrations in runoff water. Although results from these experiments typically represented a worst case scenario since runoff events generally occurred immediately after litter application, the contaminant loss from pastures fertilized with poultry litter can be expected to be much lower than continual estradiol loadings observed from waste water treatment plants. Management practices such as alum amendment and application timing can significantly reduce the risk of 17β-estradiol losses in the environment.

  18. Association of estradiol with sleep apnea in depressed perimenopausal and postmenopausal women: a preliminary study.

    PubMed

    Galvan, Thania; Camuso, Julia; Sullivan, Kathryn; Kim, Semmie; White, David; Redline, Susan; Joffe, Hadine

    2017-01-01

    Women's risk of obstructive sleep apnea (OSA) increases substantially during and after the menopausal transition, when depression risk is also elevated, raising the possibility that estrogen withdrawal contributes to OSA vulnerability, in turn contributing to mood disturbance. We examined the association between estradiol levels and OSA in depressed peri- and postmenopausal women. Thirty depressed peri-/postmenopausal women (mean body mass index [BMI] 30.82 kg/m) without known OSA completed routine polysomnography concurrent with serum estradiol levels. Estradiol in women with apnea-hypopnea indices (AHI) ≥15 indicating moderate-to-severe OSA was compared against those with AHI less than 15 using logistic regression adjusting for age and BMI. Thirteen women (43%) had AHI ≥15 (median AHI 21.6). Estradiol levels were lower (P = 0.02) in those with OSA (median 19, interquartile range 9-25 pg/mL) than without OSA (median 29, interquartile range 19-66 pg/mL). On univariate analysis, higher estradiol was associated with reduced odds of OSA (odds ratio 0.95, 95% CI 0.90-0.99, P = 0.04). After adjusting for age and BMI, estradiol levels remained associated with lower odds of OSA (odds ratio 0.90), but the association was no longer statistically significant (95% CI 0.76-1.05, P = 0.18). Montgomery Åsberg Depression Rating Scale scores did not differ between those with and without OSA. These preliminary results suggest that, in addition to higher BMI and age, lower estradiol may be associated with increased OSA risk in depressed women during the peri- and postmenopause, raising the possibility that estradiol withdrawal associated with menopause influences upper-airway patency in women.

  19. Aromatase inhibitors in obese breast cancer patients are not associated with increased plasma estradiol levels.

    PubMed

    Diorio, Caroline; Lemieux, Julie; Provencher, Louise; Hogue, Jean-Charles; Vachon, Eric

    2012-11-01

    Obesity, in postmenopausal women, has been associated to a higher breast cancer incidence and worst prognosis. Some studies suggested a decrease in aromatase inhibitors (AI) efficacy in obese postmenopausal breast cancer patients, although estradiol levels were not measured. The purpose of the present study was to verify if estradiol levels are measurable in postmenopausal women under AI. If achievable, the goal is to compare the estradiol levels in lean versus obese postmenopausal women under AI treatment for non-metastatic breast cancer. Postmenopausal women were recruited in accordance to one of these four groups: lean [body mass index (BMI) of 18-25 kg/m(2)] under AI (n = 30), obese (BMI ≥ 30 kg/m(2)) under AI (n = 30), lean AI-naïve (n = 10), and obese AI-naïve (n = 10). Lean and obese women were matched according to their age. Estradiol levels were measured in plasma using an ELISA. The Wilcoxon signed-rank test was used to assess the significance of the differences between the groups. Estradiol levels in postmenopausal women under AI varied from 0 to 94.65 pg/ml with a median value of 0.98 pg/ml. Obese AI-naïve women had higher estradiol levels than lean AI-naïve women (p = 0.03). There was no difference in estradiol levels between lean and obese women under AI (p = 0.76). Despite very low plasma levels, it is possible to measure the estradiol levels in postmenopausal women under AI treatment. Our results suggest that the known impact of obesity on recurrence risk in women under AI treatment may not be due to incomplete aromatase inhibition. Further works are needed to examine closely the aromatase-independent pathways that are linking obesity to breast cancer risk and recurrence.

  20. Effects of estradiol on uterine perfusion in anesthetized cyclic mares affected with uterine vascular elastosis.

    PubMed

    Esteller-Vico, A; Liu, I K M; Vaughan, B; Steffey, E P; Brosnan, R J

    2016-01-01

    Uterine vascular elastosis in mares is characterized by degeneration of uterine vasculature through thickening of the elastin layers. Factors commonly associated with this degeneration include age, parity, and chronic uterine endometritis. Affected mares have also been shown to exhibit decreases in uterine blood flow and perfusion of the uterus. Due to the increased thickness of the elastin layers, we hypothesize that vasodilatation of the uterine vasculature is also impaired. To test the functionality of these vessels, we evaluated the vasodilatory effects of estradiol on the uterine vascular bed in mares with normal vasculature and mares with severe elastosis. Both groups were tested in estrus and diestrus. Fluorescent microspheres were used to determine basal blood perfusion, followed by the intravenous administration of 1.0 μg/kg of 17β-estradiol. After 90 min, perfusion was measured once again to determine the vascular response to estradiol. Control mares in estrus displayed a significant increase in total uterine blood flow after the administration of estradiol when compared to baseline levels. No other group had a significant increase in total blood flow and perfusion after estradiol administration. The administration of estradiol in control mares induced regional increases in perfusion in the uterine horns and uterine body during estrus and only in the uterine horns during diestrus. Mares affected by elastosis exhibited no regional differences in perfusion levels post-estradiol administration. The difference in the vasodilatory response induced by estradiol between reproductively healthy mares and mares affected with elastosis indicates that the functionality of the affected vessels is compromised.

  1. Acute treatment with 17beta-estradiol attenuates astrocyte-astrocyte and astrocyte-neuron communication.

    PubMed

    Rao, Shilpa P; Sikdar, Sujit Kumar

    2007-12-01

    Astrocytes are now recognized as dynamic signaling elements in the brain. Bidirectional communication between neurons and astrocytes involves integration of neuronal inputs by astrocytes and release of gliotransmitters that modulate neuronal excitability and synaptic transmission. The ovarian steroid hormone, 17beta-estradiol, in addition to its rapid actions on neuronal electrical activity can rapidly alter astrocyte intracellular calcium concentration ([Ca2+]i) through a membrane-associated estrogen receptor. Using calcium imaging and electrophysiological techniques, we investigated the functional consequences of acute treatment with estradiol on astrocyte-astrocyte and astrocyte-neuron communication in mixed hippocampal cultures. Mechanical stimulation of an astrocyte evoked a [Ca2+]i rise in the stimulated astrocyte, which propagated to the surrounding astrocytes as a [Ca2+]i wave. Following acute treatment with estradiol, the amplitude of the [Ca2+]i elevation in astrocytes around the stimulated astrocyte was attenuated. Further, estradiol inhibited the [Ca2+]i rise in individual astrocytes in response to the metabotropic glutamate receptor agonist, trans-(+/-)-1-amino-1,3-cyclopentanedicarboxylic acid. Mechanical stimulation of astrocytes induced [Ca2+]i elevations and electrophysiological responses in adjacent neurons. Estradiol rapidly attenuated the astrocyte-evoked glutamate-mediated [Ca2+]i rise and slow inward current in neurons. Also, the incidence of astrocyte-induced increase in spontaneous postsynaptic current frequency was reduced in the presence of estradiol. The effects of estradiol were stereo-specific and reversible following washout. These findings may indicate that the regulation of neuronal excitability and synaptic transmission by astrocytes is sensitive to rapid estradiol-mediated hormonal control.

  2. 17β-estradiol enhances memory duration in the main olfactory bulb in CD-1 mice.

    PubMed

    Dillon, T Samuel; Fox, Laura C; Han, Crystal; Linster, Christiane

    2013-12-01

    Rodents rely heavily on odor detection, discrimination, and memory to locate food, find mates, care for pups, and avoid predators. Estrogens have been shown to increase memory retention in rodents performing spatial memory and object placement tasks. Here we evaluate the extent to which 17β-estradiol modulates memory formation and duration in the olfactory system. Adult CD-1 mice were gonadectomized and given either systemic 17β-estradiol replacement, local 17β-estradiol in the main olfactory bulb, or no replacement. Before performing the behavioral task the mice were given saline or PHTPP (an estrogen receptor β [ER-β] antagonist) via bilateral infusion into the main olfactory bulb. As the beta-type estrogen receptor (ER-β) is more abundant than the alpha-type estrogen receptor in the murine main olfactory bulb, the current study focuses on 17β-estradiol and its interactions with ERβ. Habituation, a simple, nonassociative learning task in which an animal is exposed to the same odor over successive presentations, was used to evaluate the animals' ability to detect odors and form an olfactory memory. To evaluate memory duration, we added a final trial of intertrial interval time (30 or 60 min) in which we presented the habituated odor. Neither surgical nor drug manipulation affected the ability of mice to detect or habituate to an odor. After habituation, gonadectomized 17β-estradiol-treated mice retained memory of an odor for 30 min, whereas non-estradiol-treated, 17β-estradiol+ERβ antagonist (PHTPP), and untreated male mice did not remember an odor 30 min after habituation. The results show that both systemic and local bulbar infusions of 17β-estradiol enhance odor memory duration in mice.

  3. Estradiol shows anti-skin cancer activities through decreasing MDM2 expression.

    PubMed

    Li, Li; Feng, Jianguo; Chen, Ying; Li, Shun; Ou, Mengting; Sun, Weichao; Tang, Liling

    2017-01-31

    Estradiol plays important roles in many biological responses inducing tumor genesis and cancer treatment. However, the effects of estradiol on tumors were inconsistent among a lot of researches and the mechanism is not fully understood. Our previous study indicated that splicing factor hnRNPA1 could bind to the human homologue of mouse double minute (MDM2), an oncogene which has been observed to be over-expressed in numerous types of cancers. In this research, we investigated whether and how estradiol correlate to cancer cell behaviors through heterogeneous nuclear ribonucleoprotein (hnRNPA1) and MDM2. Results showed that 10×10-13Mestradiol elevated the expression of hnRNPA1 regardless ER expression in cells, and then down-regulated the expression of MDM2. At the same time, estradiol inhibited cell proliferation, migration and epithelial-mesenchymal transition progression of A375 and GLL19 cells. While, knocking down hnRNPA1 through the transfection of hnRNPA1 siRNA led to the increase of MDM2 at both protein level and gene level In vivo experiment, subcutaneous injection with estradiol every two days near the tumor at doses of 2.5mg/kg/d suppressed tumor growth and reduced MDM2 expression. In a word, via increasing hnRNPA1 level and then reducing the expression of MDM2, estradiol prevented carcinogenesis in melanomas. We confirmed therapeutic effect of estradiol, as well as a new way for estradiol to resist skin cancer.

  4. Methods for long-term 17β-estradiol administration to mice.

    PubMed

    Ingberg, E; Theodorsson, A; Theodorsson, E; Strom, J O

    2012-01-01

    Rodent models constitute a cornerstone in the elucidation of the effects and biological mechanisms of 17β-estradiol. However, a thorough assessment of the methods for long-term administration of 17β-estradiol to mice is lacking. The fact that 17β-estradiol has been demonstrated to exert different effects depending on dose emphasizes the need for validated administration regimens. Therefore, 169 female C57BL/6 mice were ovariectomized and administered 17β-estradiol using one of the two commonly used subcutaneous methods; slow-release pellets (0.18 mg, 60-day release pellets; 0.72 mg, 90-day release pellets) and silastic capsules (with/without convalescence period, silastic laboratory tubing, inner/outer diameter: 1.575/3.175 mm, filled with a 14 mm column of 36 μg 17β-estradiol/mL sesame oil), or a novel peroral method (56 μg 17β-estradiol/day/kg body weight in the hazelnut cream Nutella). Forty animals were used as ovariectomized and intact controls. Serum samples were obtained weekly for five weeks and 17β-estradiol concentrations were measured using radioimmunoassay. The peroral method resulted in steady concentrations within--except on one occasion--the physiological range and the silastic capsules produced predominantly physiological concentrations, although exceeding the range by maximum a factor three during the first three weeks. The 0.18 mg pellet yielded initial concentrations an order of magnitude higher than the physiological range, which then decreased drastically, and the 0.72 mg pellet produced between 18 and 40 times higher concentrations than the physiological range during the entire experiment. The peroral method and silastic capsules described in this article constitute reliable modes of administration of 17β-estradiol, superior to the widely used commercial pellets.

  5. Voluntary Exercise Impairs Initial Delayed Spatial Alternation Performance in Estradiol Treated Ovariectomized Middle-Aged Rats

    PubMed Central

    Neese, Steven L.; Korol, Donna L.; Schantz, Susan L.

    2013-01-01

    Estrogens differentially modulate behavior in the adult female rodent. Voluntary exercise can also impact behavior, often reversing age associated decrements in memory processes. Our research group has published a series of papers reporting a deficit in the acquisition of an operant working memory task, delayed spatial alternation (DSA), following 17β-estradiol treatment to middle-aged ovariectomized (OVX) rats. The current study examined if voluntary exercise could attenuate the 17β-estradiol induced deficits on DSA performance. OVX 12-month old Long- Evans rats were implanted with a Silastic capsule containing 17β-estradiol (10% in cholesterol: low physiological range) or with a blank capsule. A subset of the 17β-estradiol and OVX untreated rats were given free access to a running wheel in their home cage. All rats were tested for 40 sessions on the DSA task. Surprisingly, we found running wheel access to impair initial acquisition of the DSA task in 17β-estradiol treated rats, an effect not seen in OVX untreated rats given running wheel access. This deficit was driven by an increase in perseverative responding on a lever no longer associated with reinforcement. We also report for the first time a 17β-estradiol induced impairment on the DSA task following a long intertrial delay (18-sec), an effect revealed following more extended testing than in our previous studies (15 additional sessions). Overall, running wheel access increased initial error rate on the DSA task in 17β-estradiol treated middle-aged OVX rats, and failed to prevent the 17β-estradiol induced deficits in performance of the operant DSA task in later testing sessions. PMID:24013039

  6. Leptin Signaling Is Not Required for Anorexigenic Estradiol Effects in Female Mice.

    PubMed

    Kim, Joon S; Rizwan, Mohammed Z; Clegg, Deborah J; Anderson, Greg M

    2016-05-01

    Estradiol and leptin are critical hormones in the regulation of body weight. The aim of this study was to determine whether this cross talk between leptin receptor (LepRb) and estrogen receptor-α (ERα) signaling is critical for estradiol's anorexigenic effects. Leprb-Cre mice were crossed with Cre-dependent Tau-green fluorescent protein (GFP) reporter, Stat3-flox or Erα-flox mice to generate female mice with GFP expression, signal transducer and activator of transcription 3 (STAT3) knockout (KO), or ERα KO, specifically in LepRb-expressing cells. The proportion of Leprb-GFP cells colocalizing ERα was high (∼80%) in the preoptic area but low (∼10%) in the mediobasal hypothalamus, suggesting that intracellular cross talk between these receptors is minimal for metabolic regulation. To test whether estradiol enhanced arcuate leptin sensitivity, ovarectomized mice received varying levels of estradiol replacement. Increasing estrogenic states did not increase the degree of leptin-induced STAT3 phosphorylation. LepRb-specific STAT3 KO mice and controls were ovarectomized and given either chronic estradiol or vehicle treatment to test whether STAT3 is required for estrogen-induced body weight suppression. Both groups of estradiol-treated mice showed an equivalent reduction in body weight and fat content compared with vehicle controls. Finally, mice lacking ERα specifically in LepRb-expressing neurons also showed no increase in body weight or impairments in metabolic function compared with controls, indicating that estradiol acts independently of leptin-responsive cells to regulate body weight. However, fecundity was impaired in in Leprb-ERα KO females. Contrary to the current dogma, we report that estradiol has minimal direct actions on LepRb cells in the mediodasal hypothalamus and that its anorexigenic effects can occur entirely independently of LepRb-STAT3 signaling in female mice.

  7. Estradiol Stimulates Vasodilatory and Metabolic Pathways in Cultured Human Endothelial Cells

    PubMed Central

    Sobrino, Agua; Mata, Manuel; Laguna-Fernandez, Andrés; Novella, Susana; Oviedo, Pilar J.; García-Pérez, Miguel Angel; Tarín, Juan J.; Cano, Antonio; Hermenegildo, Carlos

    2009-01-01

    Vascular effects of estradiol are being investigated because there are controversies among clinical and experimental studies. DNA microarrays were used to investigate global gene expression patterns in cultured human umbilical vein endothelial cells (HUVEC) exposed to 1 nmol/L estradiol for 24 hours. When compared to control, 187 genes were identified as differentially expressed with 1.9-fold change threshold. Supervised principal component analysis and hierarchical cluster analysis revealed the differences between control and estradiol-treated samples. Physiological concentrations of estradiol are sufficient to elicit significant changes in HUVEC gene expression. Notch signaling, actin cytoskeleton signaling, pentose phosphate pathway, axonal guidance signaling and integrin signaling were the top-five canonical pathways significantly regulated by estrogen. A total of 26 regulatory networks were identified as estrogen responsive. Microarray data were confirmed by quantitative RT-PCR in cardiovascular meaning genes; cyclooxigenase (COX)1, dimethylarginine dimethylaminohydrolase (DDAH)2, phospholipase A2 group IV (PLA2G4) B, and 7-dehydrocholesterol reductase were up-regulated by estradiol in a dose-dependent and estrogen receptor-dependent way, whereas COX2, DDAH1 and PLA2G4A remained unaltered. Moreover, estradiol-induced COX1 gene expression resulted in increased COX1 protein content and enhanced prostacyclin production. DDAH2 protein content was also increased, which in turn decreased asymmetric dimethylarginine concentration and increased NO release. All stimulated effects of estradiol on gene and protein expression were estrogen receptor-dependent, since were abolished in the presence of the estrogen receptor antagonist ICI 182780. This study identifies new vascular mechanisms of action by which estradiol may contribute to a wide range of biological processes. PMID:20011585

  8. Modulation of SHBG binding to testosterone and estradiol by sex and morbid obesity.

    PubMed

    Grasa, María Del Mar; Gulfo, José; Camps, Núria; Alcalá, Rosa; Monserrat, Laura; Moreno-Navarrete, José María; Ortega, Francisco José; Esteve, Montserrat; Remesar, Xavier; Fernández-López, José Antonio; Fernández-Real, José Manuel; Alemany, Marià

    2017-04-01

    Sex hormone-binding globulin (SHBG) binds and transports testosterone and estradiol in plasma. The possibility that SHBG is a mixture of transporting proteins has been postulated. We analyzed in parallel the effects of obesity status on the levels and binding capacity of circulating SHBG and their relationship with testosterone and estradiol. Anthropometric measures and plasma were obtained from apparently healthy young (i.e. 35 ± 7 years) premenopausal women (n = 32) and men (n = 30), with normal weight and obesity (BMI >30 kg/m(2)). SHBG protein (Western blot), as well as the plasma levels of testosterone, estradiol, cortisol and insulin (ELISA) were measured. Specific binding of estradiol and testosterone to plasma SHBG was analyzed using tritium-labeled hormones. Significant differences in SHBG were observed within the obesity status and gender, with discordant patterns of change in testosterone and estradiol. In men, testosterone occupied most of the binding sites. Estrogen binding was much lower in all subjects. Lower SHBG of morbidly obese (BMI >40 kg/m(2)) subjects affected testosterone but not estradiol. The ratio of binding sites to SHBG protein levels was constant for testosterone, but not for estradiol. The influence of gender was maximal in morbid obesity, with men showing the highest binding/SHBG ratios. The results reported here are compatible with SHBG being a mixture of at least two functionally different hormone-binding globulins, being affected by obesity and gender and showing different structure, affinities for testosterone and estradiol and also different immunoreactivity. © 2017 European Society of Endocrinology.

  9. Synchronization of estrus in beef cattle with norgestomet and estradiol valerate.

    PubMed Central

    Kastelic, J P; Olson, W O; Martinez, M; Cook, R B; Mapletoft, R J

    1999-01-01

    Fifty-six cows received a norgestomet implant and an injection of norgestomet and estradiol valerate; half (n = 28) received 500 IU equine chorionic gonadotrophin (eCG) at implant removal, 9 d later. A third group (n = 25) received 2 doses of cloprostenol (500 micrograms) 11 d apart. Estrous rate was higher (P < 0.05) for cows given norgestomet and estradiol plus 500 IU eCG (75.0%) than for those receiving cloprostenol (44.0%); for those receiving norgestomet and estradiol alone, it was intermediate (67.8%). Pregnancy rates to artificial insemination (after estrus or timed) were higher (P < 0.05) for cows given norgestomet and estradiol than for those given cloprostenol (23 of 28, 82.1% vs 13 of 25, 52.0%), and intermediate (67.8%) for those given norgestomet and estradiol plus eCG. In a second experiment, for heifers treated with norgestomet and estradiol plus eCG (n = 15) or with 2 doses of cloprostenol (n = 16), estrous rates were 66.7% vs 56.2% (P > 0.5), ovulation rates were 100.0% vs 81.2% (P = 0.08), intervals from implant removal or cloprostenol treatment to estrus were 48.0 +/- 4.4 hours vs 61.3 +/- 7.0 hours (P = 0.12) and to ovulation were 70.4 +/- 4.4 hours vs 93.2 +/- 7.5 hours (P < 0.01), respectively; pregnancy rates were 41.7 and 35.7%, respectively (P > 0.5). Norgestomet and estradiol were as good as (heifers) or superior to (cows) a 2-dose cloprostenol regimen. In cows given norgestomet and estradiol, injecting eCG at implant removal did not significantly improve estrous or pregnancy rates. PMID:10086217

  10. Powerline frequency electric and magnetic fields: a pilot study of risk perception.

    PubMed

    Morgan, M G; Slovic, P; Nair, I; Geisler, D; MacGregor, D; Fischhoff, B; Lincoln, D; Florig, K

    1985-06-01

    The perception of the potential risk arising from human exposure to 50/60 Hz electric and magnetic fields was studied with a quasi-random sample of 116 well-educated, opinion leaders using the risk perception framework previously developed by Slovic, Fischhoff, and Lichtenstein. These individuals rated exposure to fields from transmission lines and electric blankets on a variety of scales that have been found useful in characterizing people's risk attitudes and perceptions. These judgments allowed us to conjecture about the likely desire for regulation of these potential hazards and the likely response to a publicized problem (e.g., an accident or ominous research finding) involving these two sources of exposure. Various forms of detailed information about 50/60 Hz fields were supplied to respondents. The provision of information produced modest, but statistically significant, changes in perceptions in the direction of greater concern about the risks. In response to questions of public policy, participants desired modest regulatory control of field exposure from transmission lines and little or no control of field exposure from appliances like electric blankets.

  11. Brain-derived neurotrophic factor mediates estradiol-induced dendritic spine formation in hippocampal neurons.

    PubMed

    Murphy, D D; Cole, N B; Segal, M

    1998-09-15

    Dendritic spines are of major importance in information processing and memory formation in central neurons. Estradiol has been shown to induce an increase of dendritic spine density on hippocampal neurons in vivo and in vitro. The neurotrophin brain-derived neurotrophic factor (BDNF) recently has been implicated in neuronal maturation, plasticity, and regulation of GABAergic interneurons. We now demonstrate that estradiol down-regulates BDNF in cultured hippocampal neurons to 40% of control values within 24 hr of exposure. This, in turn, decreases inhibition and increases excitatory tone in pyramidal neurons, leading to a 2-fold increase in dendritic spine density. Exogenous BDNF blocks the effects of estradiol on spine formation, and BDNF depletion with a selective antisense oligonucleotide mimics the effects of estradiol. Addition of BDNF antibodies also increases spine density, and diazepam, which facilitates GABAergic neurotransmission, blocks estradiol-induced spine formation. These observations demonstrate a functional link between estradiol, BDNF as a potent regulator of GABAergic interneurons, and activity-dependent formation of dendritic spines in hippocampal neurons.

  12. Hernia fibroblasts lack β-estradiol induced alterations of collagen gene expression

    PubMed Central

    2006-01-01

    Background Estrogens are reported to increase type I and type III collagen deposition and to regulate Metalloproteinase 2 (MMP-2) expression. These proteins are reported to be dysregulated in incisional hernia formation resulting in a significantly decreased type I to III ratio. We aimed to evaluate the β-estradiol mediated regulation of type I and type III collagen genes as well as MMP-2 gene expression in fibroblasts derived from patients with or without history of recurrent incisional hernia disease. We compared primary fibroblast cultures from male/female subjects without/without incisional hernia disease. Results Incisional hernia fibroblasts (IHFs) revealed a decreased type I/III collagen mRNA ratio. Whereas fibroblasts from healthy female donors responded to β-estradiol, type I and type III gene transcription is not affected in fibroblasts from males or affected females. Furthermore β-estradiol had no influence on the impaired type I to III collagen ratio in fibroblasts from recurrent hernia patients. Conclusion Our results suggest that β-estradiol does not restore the imbaired balance of type I/III collagen in incisional hernia fibroblasts. Furthermore, the individual was identified as an independent factor for the β-estradiol induced alterations of collagen gene expression. The observation of gender specific β-estradiol-dependent changes of collagen gene expression in vitro is of significance for future studies of cellular response. PMID:17010202

  13. Promotion of human adipocyte precursor replication by 17beta-estradiol in culture.

    PubMed Central

    Roncari, D A; Van, R L

    1978-01-01

    The influence of 17beta-estradiol and 17alpha-estradiol on adult human omental adipocyte precursors grown in a propagating culture system was studied. Cells were grown in subculture in the presence or absence of hormone. 17beta-estradiol resulted in significant promotion of adipocyte precursor replication, as determined by cell counting and incorporation of radioactive thymidine into DNA. The hormone stimulated cell multiplication in the concentration range 0.5--500 ng/ml growth medium. The highest level tested was 500 ng/ml. The maximal effects were obtained at 50 ng/ml (P less than 0.001 by paired t test, 48 h after hormone addition). All 10 cell strains (five were derived from men and five from women) that were tested responded similarly to the hormone. 17beta-estradiol did not affect cell size. 17alpha-estradiol did not promote the replication of adipocyte precursors, nor did it influence cell size. Thus, 17beta-estradiol, which is the active isomer in known target tissues, stimulates the multiplication of human adipocyte precursors in culture. Images PMID:690182

  14. Modulatory Effects of Sex Steroids Progesterone and Estradiol on Odorant Evoked Responses in Olfactory Receptor Neurons

    PubMed Central

    Scholz, Paul; Mohrhardt, Julia; Gisselmann, Günter; Hatt, Hanns

    2016-01-01

    The influence of the sex steroid hormones progesterone and estradiol on physiology and behavior during menstrual cycles and pregnancy is well known. Several studies indicate that olfactory performance changes with cyclically fluctuating steroid hormone levels in females. Knowledge of the exact mechanisms behind how female sex steroids modulate olfactory signaling is limited. A number of different known genomic and non-genomic actions that are mediated by progesterone and estradiol via interactions with different receptors may be responsible for this modulation. Next generation sequencing-based RNA-Seq transcriptome data from the murine olfactory epithelium (OE) and olfactory receptor neurons (ORNs) revealed the expression of several membrane progestin receptors and the estradiol receptor Gpr30. These receptors are known to mediate rapid non-genomic effects through interactions with G proteins. RT-PCR and immunohistochemical staining results provide evidence for progestin and estradiol receptors in the ORNs. These data support the hypothesis that steroid hormones are capable of modulating the odorant-evoked activity of ORNs. Here, we validated this hypothesis through the investigation of steroid hormone effects by submerged electro-olfactogram and whole cell patch-clamp recordings of ORNs. For the first time, we demonstrate that the sex steroid hormones progesterone and estradiol decrease odorant-evoked signals in the OE and ORNs of mice at low nanomolar concentrations. Thus, both of these sex steroids can rapidly modulate the odor responsiveness of ORNs through membrane progestin receptors and the estradiol receptor Gpr30. PMID:27494699

  15. Consequences of nongenomic actions of estradiol on pathogenic genital tract response

    PubMed Central

    2013-01-01

    Estradiol is a steroid hormone that regulates the structure and function of the female reproductive system. In addition to its genomic effects, which are mediated by activated nuclear receptors, estradiol elicits a variety of rapid signaling events independently of transcriptional or genomic regulation. These nongenomic actions influence the milieu of the genital tract, which changes the ability of pathogens to infect the genital tract. This review discusses our current knowledge regarding the mechanisms and relevance of nongenomic estradiol signaling in the genital tract that could change the ability of pathogens to invade epithelial cells. PubMed was searched through January 1980 for papers related to estradiol actions in the ovary, fallopian tube, uterus and cervix. The mechanisms conveying these rapid effects consist of a multitude of signaling molecules and include cross-talk with slower transcriptional actions. The nongenomic actions of estradiol that influence the infectious abilities of pathogens occur either directly on the genital tract cells or indirectly by modulating the local and systemic immune systems. Additional in-depth characterization of the response is required before the normal and pathological reproductive functions of the nongenomic estradiol pathway can be targeted for pharmacological intervention. PMID:23351368

  16. Sex, estradiol, and spatial memory in a food-caching corvid.

    PubMed

    Rensel, Michelle A; Ellis, Jesse M S; Harvey, Brigit; Schlinger, Barney A

    2015-09-01

    Estrogens significantly impact spatial memory function in mammalian species. Songbirds express the estrogen synthetic enzyme aromatase at relatively high levels in the hippocampus and there is evidence from zebra finches that estrogens facilitate performance on spatial learning and/or memory tasks. It is unknown, however, whether estrogens influence hippocampal function in songbirds that naturally exhibit memory-intensive behaviors, such as cache recovery observed in many corvid species. To address this question, we examined the impact of estradiol on spatial memory in non-breeding Western scrub-jays, a species that routinely participates in food caching and retrieval in nature and in captivity. We also asked if there were sex differences in performance or responses to estradiol. Utilizing a combination of an aromatase inhibitor, fadrozole, with estradiol implants, we found that while overall cache recovery rates were unaffected by estradiol, several other indices of spatial memory, including searching efficiency and efficiency to retrieve the first item, were impaired in the presence of estradiol. In addition, males and females differed in some performance measures, although these differences appeared to be a consequence of the nature of the task as neither sex consistently out-performed the other. Overall, our data suggest that a sustained estradiol elevation in a food-caching bird impairs some, but not all, aspects of spatial memory on an innate behavioral task, at times in a sex-specific manner.

  17. Gender-dependent negative correlation of peripheral E2 estradiol levels with ventricular diastolic functions.

    PubMed

    Tan, Bo; Zhao, Lili; FaweiHE, Fawei

    2016-08-01

    The aim of this study to investigate the correlation of the peripheral concentrations of one representative estrogen, E2 estradiol, with various indicators reflecting different aspects of cardiac structures and functions. A total of 84 typical patients with hypertrophic cardiomyopathy (HCM) and 77 healthy subjects were enrolled. Venous blood samples were taken to test E2 estradiol contents. Echocardiographic imaging was performed to record various indices of cardiac structures and functions. Concentrations of peripheral E2 estradiol were decreased in female HCM patients, compared to female normal controls; after medical treatment, peripheral E2 estradiol levels were elevated, nearly to normal levels. Peripheral E2 estradiol concentrations were negatively correlated with LAV (r2=0.5078, P<0.001), LAVI (r2=0.4257, P<0.001), E/A ratio (r2=0.4328, P=0.006) and E/Ea ratio (r2=0.4393, P<0.001) in female controls and patients. Concentrations of peripheral E2 estradiol were negatively correlated with ventricular diastolic functions and this correlation was gender-dependent. Our study could provide clues to explore the molecular mechanisms of HCM, and clinic evidence for the diagnosis and prognostic management of HCM patients, as well as medical intervening for HCM.

  18. Altered functional brain asymmetry for mental rotation: effect of estradiol changes across the menstrual cycle

    PubMed Central

    Zhu, Xun; Kelly, Thomas H.; Curry, Thomas E.; Lal, Chitra; Joseph, Jane E.

    2015-01-01

    Mental rotation is a visuo-spatial task associated with pronounced sex differences. Performance is also affected by gonadal hormones such as testosterone and estradiol. To better understand hormonal modulation of the neural substrates of mental rotation, the present study examined the influence of estradiol using functional magnetic resonance imaging. Ten pre-menopausal women were tested on a 3D mental rotation task during the early follicular (EF) and late follicular (LF) phases of the menstrual cycle. Change in estradiol between the two phases was confirmed by hormone assays. Brain activation patterns were similar across the two phases, but the change in estradiol had different associations with the two hemispheres. Better performance in the LF than the EF phase was associated with a pattern of reduced recruitment of the right hemisphere and increased recruitment of the left hemisphere. The increased recruitment of the left hemisphere was directly associated with greater changes in estradiol. Given that the right hemisphere is the dominant hemisphere in visuo-spatial processing, our results suggest that estradiol is associated with reduced functional asymmetry, consistent with recent accounts of hormonal modulation of neurocognitive function. PMID:26222958

  19. Altered functional brain asymmetry for mental rotation: effect of estradiol changes across the menstrual cycle.

    PubMed

    Zhu, Xun; Kelly, Thomas H; Curry, Thomas E; Lal, Chitra; Joseph, Jane E

    2015-09-30

    Mental rotation is a visuospatial task associated with pronounced sex differences. Performance is also affected by gonadal hormones such as testosterone and estradiol. To better understand hormonal modulation of the neural substrates of mental rotation, the present study examined the influence of estradiol using functional MRI. Ten premenopausal women were tested on a 3D mental rotation task during the early follicular and late follicular phases of the menstrual cycle. Change in estradiol between the two phases was confirmed by hormone assays. Brain activation patterns were similar across the two phases, but the change in estradiol had different associations with the two hemispheres. Better performance in the late follicular than the early follicular phase was associated with a pattern of reduced recruitment of the right hemisphere and increased recruitment of the left hemisphere. The increased recruitment of the left hemisphere was directly associated with greater changes in estradiol. Given that the right hemisphere is the dominant hemisphere in visuospatial processing, our results suggest that estradiol is associated with reduced functional asymmetry, consistent with recent accounts of hormonal modulation of neurocognitive function.

  20. Characterization of a 7 day 17 beta-estradiol transdermal delivery system: pharmacokinetics in healthy postmenopausal women.

    PubMed

    Boyd, R A; Zegarac, E A; Eldon, M A; Sedman, A J; Forgue, S T

    1996-08-01

    To assess the delivery characteristics of a new 7 day 17 beta-estradiol transdermal delivery system (TDS), estradiol and estrone pharmacokinetics were evaluated following a single 7 d application of one TDS or two TDSs in 24 healthy, postmenopausal women in a nonblind, randomized, two-period crossover study. Serial blood samples and total urine output were collected before (baseline measurement of endogenous hormone) and during TDS application, and for 24 h (urine) or 72 h (blood) following TDS removal. Serum was assayed for estradiol and estrone by a validated radioimmunoassay (RIA) method. The combined amounts of estradiol and its conjugates, and estrone and its conjugates in urine were determined by validated RIA methods. Overall, one or two estradiol TDSs were well tolerated by healthy, postmenopausal female volunteers. Estradiol absorption from the TDS was characterized by a zero-order process and was dose proportional, resulting in average steady-state serum estradiol concentrations of 16 and 33 pg mL-1 above baseline during the 7 d application of one and two TDSs, respectively. Parallel but smaller increases in serum estrone concentrations were observed, resulting in an increase in the serum estradiol/estrone concentration ratio from approximately 0.2 at baseline to median values of 0.64 and 0.88 during application of one and two TDSs, respectively. The 7 day 17 beta-estradiol TDS delivered a nominal estradiol dose of 0.02 mg/24 h during the intended wear period.

  1. Estradiol levels in girls with Turner's syndrome compared to normal prepubertal girls as determined by an ultrasensitive assay.

    PubMed

    Wilson, Courtnay A; Heinrichs, Claudine; Larmore, Kimberly A; Craen, Marguerita; Brown-Dawson, Jacquelyn; Shaywitz, Sally; Ross, Judith; Klein, Karen Oerter

    2003-01-01

    Based on growing evidence that estradiol is produced in small amounts even in the prepubertal ovary, we hypothesized that estradiol levels in girls with Turner's syndrome (TS) are lower than in normal prepubertal girls secondary to the lack of normally functioning ovaries. Estradiol levels in untreated girls with TS have not been previously well defined because of the lack of adequate sensitivity of previously available estradiol assays. We utilized an ultrasensitive assay to study estradiol levels in 34 girls with TS and 34 normal age-matched prepubertal girls between the ages of 5 and 12 years. The average estradiol level in the girls with TS (6.4 +/- 4.9 pmol/l estradiol equivalents) was significantly lower than in the normal prepubertal girls (12.7 +/- 10.8 pmol/l estradiol equivalents; p < 0.01). Girls with TS were significantly shorter, and weighed less than the normal prepubertal girls, as expected. The estradiol level was not significantly correlated with height, bone age, or degree of bone age delay. In conclusion, girls with TS have significantly lower estradiol levels than normal age-matched prepubertal girls. This report is consistent with the hypothesis that the lack of normal ovarian function in girls with TS is evident even before puberty.

  2. Metabolism of estradiol in greyhounds and German shepherd dogs. An investigation with special reference to hip dysplasia.

    PubMed

    Beling, C G; Gustafsson, P O; Kasström, H

    1975-01-01

    Metabolism of estradiol was investigated in 5 dogs, 3 female Greyhounds with radiographically perfect hip joints and 2 female German Shepherd dogs with hip dysplasia (one pregnant and the other non-pregnant). One of the Greyhounds was studied both when pregnant and non-pregnant. The non-pregnant dogs were injected with C14-labelled estradiol-17beta i.v. and 5 mg estradiol-17beta benzoate i.m. The pregnant dogs were given only radiolabelled estradiol-17beta. Twenty-four-hour-specimens of urine were collected from the dogs for 6--8 days. Determination of urinary estrone, estradiol-17beta, and estriol was made. It was found that most of the injected estradiol was excreted unmetabolized in all dogs. A significant amount of the injected estradiol was converted to estrone and a small amount to estriol. There was no significant difference in the excretion patterns of estrone, estradiol, and estriol between the Greyhounds with perfect hip joints and the German Shepherds with hip dysplasia, regardless whether the dogs were pregnant or not. The conclusion was drawn that the capacity of dogs with hip dysplasia to metabolize estradiol and to eliminate estradiol and metabolites is not impaired.

  3. Catechol-O-methyltransferase is dispensable for vascular protection by estradiol in mouse models of atherosclerosis and neointima formation.

    PubMed

    Wilhelmson, Anna S; Bourghardt-Fagman, Johan; Gogos, Joseph A; Fogelstrand, Per; Tivesten, Asa

    2011-12-01

    Estradiol is converted to the biologically active metabolite 2-methoxyestradiol via the activity of the enzyme catechol-O-methyltransferase (COMT). Exogenous administration of both estradiol and 2-methoxyestradiol reduces experimental atherosclerosis and neointima formation, and COMT-dependent formation of 2-methoxyestradiol likely mediates the antimitogenic effect of estradiol on smooth muscle cells in vitro. This study evaluated whether 2-methoxyestradiol mediates the vasculoprotective actions of estradiol in vivo. Wild-type (WT) and COMT knockout (COMTKO) mice on an apolipoprotein E-deficient background were gonadectomized and treated with estradiol or placebo. Exogenous estradiol reduced atherosclerotic lesion formation in both females (WT, -78%; COMTKO, -82%) and males (WT, -48%; COMTKO, -53%) and was equally effective in both genotypes. We further evaluated how exogenous estradiol affected neointima formation after ligation of the carotid artery in ovariectomized female mice; estradiol reduced intimal hyperplasia to a similar extent in both WT (-80%) and COMTKO (-77%) mice. In ovarian-intact female COMTKO mice, atherosclerosis was decreased (-25%) compared with WT controls. In conclusion, the COMT enzyme is dispensable for vascular protection by exogenous estradiol in experimental atherosclerosis and neointima formation in vivo. Instead, COMT deficiency in virgin female mice with intact endogenous production of estradiol results in relative protection against atherosclerosis.

  4. Modeling Sorption and Degradation of 17β-Estradiol-17-Sulfate in Agricultural Soils

    NASA Astrophysics Data System (ADS)

    Bai, X.; Casey, F. X.; Hakk, H.; Shrestha, S. L.; DeSutter, T.; Khan, E.; Oduor, P. G.

    2011-12-01

    The natural steroid hormone, 17β-estradiol (E2), can be an endocrine disruptor at part-per trillion levels. Laboratory studies indicate a low potential for E2 persistence and mobility in the environment; however, field studies consistently indicate the presence of E2 and its primary metabolite, estrone, at levels sufficiently high to impact water quality. To facilitate urine excretion, animals may release E2 as a sulfated conjugate, which would have a higher aqueous solubility than the parent compound. We hypothesize that E2 conjugates contribute to the detection of free estrogens in the environment. The objective of this study was to determine the sorption, degradation, and mobility of a model conjugate, 17β-estradiol-17-sulfate (E2-17S), in agricultural soils. Radiolabeled E2-17S ([14C]E2-17S) was chemically synthesized in a three-step process, and then batch experiments were conducted in natural and sterile soils. Additionally, soil organic carbon (OC) was varied (1.29 and 0.26%) to investigate its effect on the fate of [14C]E2-17S. Liquid scintillation counting (LSC) was used in concert with high performance liquid chromatography (HPLC) to detect and quantitate parent compound and metabolites of E2-17S in the aqueous and bound phases. Residual soil was combusted to determine non-extractable levels of 14C. The E2-17S was relatively stable in the aqueous phase for natural and sterile soils. Mono- and di- hydroxyl E2-17S were detected as metabolites of E2-17S in the aqueous phase above both sterile and natural soil. Deconjugation to form E2 was not observed in aqueous phase; however, E2 and estrone were extracted from both natural and sterile soils. A conceptual model was developed to simulate and identify the fate and transport processes of E2-17S. Organic carbon was found to be an important factor affecting the sorption and degradation of E2-17S in soils.

  5. 17β-Estradiol attenuates the activity of the glutamate transporter type 3 expressed in Xenopus oocytes.

    PubMed

    Na, Hyo-Seok; Park, Hee-Pyeong; Kim, Chong-Sung; Do, Sang-Hwan; Zuo, Zhiyi; Kim, Chong-Soo

    2012-02-15

    Estrogen, a neuroactive sex hormone in the brain, enhances neuronal excitability and increases seizures. Glutamate transporters help in limiting the excitatory neurotransmission by uptaking glutamate from the synapses. We investigated the effects of 17β-estradiol on the activity of a glutamate transporter, excitatory amino acid transporter 3 (EAAT3), in Xenopus oocytes. EAAT3 was expressed in Xenopus oocytes by injection of rat EAAT3 mRNA. l-Glutamate (30 μM)-induced membrane currents mediated by EAAT3 were measured using the two-electrode voltage clamp technique. 17β-Estradiol reduced EAAT3 activity in a concentration- and time-dependent manner. 17β-Estradiol (10nM for 72h) significantly decreased V(max) but had no effect on K(m) of EAAT3 for glutamate. When 17β-estradiol treated oocytes were incubated with phorbol-12-myrisate-13-acetate, a protein kinase C (PKC) activator, 17β-estradiol-induced decrease in EAAT3 activity was abolished. Furthermore, in pretreatment of oocytes with chelerythrine or staurosporine, two PKC inhibitors, EAAT3 activity was significantly decreased. However, there was no statistical difference among the 17β-estradiol, PKC inhibitor, or 17β-estradiol plus PKC inhibitor groups. Likewise, wortmannin, a phosphatidylinositol 3-kinase (PI3K) inhibitor, significantly reduced basal EAAT3 activity, but the activity did not differ among the 17β-estradiol, wortmannin, or 17β-estradiol plus wortmannin groups. Estradiol receptor inhibitor, fulvestrant, did not change the reduced EAAT3 activity by 17β-estradiol. Our results suggest that 17β-estradiol decreases EAAT3 activity. PKC and PI3K seem to be involved in this effect, possibly not via estradiol receptors.

  6. Behavioral evidence that magnetic field effects in the land snail, Cepaea nemoralis, might not depend on magnetite or induced electric currents

    SciTech Connect

    Prato, F.S.; Kavaliers, M.; Carson, J.J.L.

    1996-05-01

    Although extremely low frequency (ELF) magnetic fields (< 300 Hz) appear to exert a variety of biological effects, the magnetic field sensing/transduction mechanism(s) remains to be established. Here, using the inhibitory effects of magnetic fields on endogenous opioid peptide-mediated analgesic response of the land snail, Cepaea nemoralis, the authors addressed the mechanism(s) of action of ELF magnetic fields. Indirect mechanisms involving both induced electric fields and direct magnetic field detection mechanisms (e.g., magnetite, parametric resonance) were evaluated. Snails were exposed to a static magnetic field (B{sub DC} = 78 {+-} 1 {micro}T) and a 60 Hz magnetic field (B{sub AC} = 299 {+-} 1 {micro}T peak) with the angle between the static and 60 Hz magnetic fields varied in eight steps between 0{degree} and 90{degree}. At 0{degree} and 90{degree}, the magnetic field reduced opioid-induced analgesia by approximately 20%, and this inhibition was increased to a maximum of 50% when the angle was between 50{degree} and 70{degree}. Because B{sub AC} was fixed in amplitude, direction, and frequency, any induced electric currents would be constant independent of the B{sub AC}/B{sub DC} angle. Also, an energy transduction mechanism involving magnetite should show greatest sensitivity at 90{degree}. Therefore, the energy transduction mechanism probably does not involve induced electric currents or magnetite. Rather, their results suggest a direct magnetic field detection mechanism consistent with the parametric resonance model proposed by Lednev.

  7. 17β-Estradiol Attenuates Poststroke Depression and Increases Neurogenesis in Female Ovariectomized Rats

    PubMed Central

    Cheng, Yifan; Su, Qiaoer; Shao, Bei; Cheng, Jianhua; Wang, Hong; Wang, Liuqing; Lin, Zhenzhen; Ruan, Linhui; ZhuGe, Qichuan; Jin, Kunlin

    2013-01-01

    Studies have linked neurogenesis to the beneficial actions of specific antidepressants. However, whether 17β-estradiol (E2), an antidepressant, can ameliorate poststroke depression (PSD) and whether E2-mediated improvement of PSD is associated with neurogenesis are largely unexplored. In the present study, we found that depressive-like behaviors were observed at the first week after focal ischemic stroke in female ovariectomized (OVX) rats, as measured by sucrose preference and open field test, suggesting that focal cerebral ischemia could induce PSD. Three weeks after middle cerebral artery occlusion (MCAO), rats were treated with E2 for consecutive 14 days. We found that E2-treated rats had significantly improving ischemia-induced depression-like behaviors in the forced-swimming test and sucrose preference test, compared to vehicle-treated group. In addition, we also found that BrdU- and doublecortin (DCX)-positive cells in the dentate gyrus of the hippocampus and the subventricular zone (SVZ) were significantly increased in ischemic rats after E2 treatment, compared to vehicle-treated group. Our data suggest that focal cerebral ischemia can induce PSD, and E2 can ameliorate PSD. In addition, newborn neurons in the hippocampus may play an important role in E2-mediated antidepressant like effect after ischemic stroke. PMID:24307996

  8. [Chlorination of ethynyl estradiol: a kinetic and mechanistic study].

    PubMed

    Wang, Bin-Nan; Liu, Guo-Qiang; Kong, De-Yang; Lu, Jun-He

    2013-06-01

    The objective of this research is to explore the fundamentals of reactions between chlorine and ethynyl estradiol (EE2), which is expected to occur during the drinking water treatment. The first step of EE2 chlorination was shown to follow the second-order kinetics with the first order to concentrations of both target compound and chlorine, respectively. Apparent rate constants of EE2 chlorination exhibit the pH-dependent profile which indicates that the phenolic ring is the preferred site of attack by Cl. The transformation of EE2 is governed by 3 elementary reactions between different species of EE2 and HClO. The deprotonated EE2 anion is significantly more reactive than its neutral conjugate. HPLC/MS analysis revealed that several Cl atoms can be incorporated into this site via complex multi-step pathways, resulting in the formation of mono and di-chlorine substituted EE2. The incorporation of the third Cl is accompanied by immediate broken down of the ring via hydrolysis. The results of this study are helpful to fully understand the behavior of EE2 in chlorinated drinking water disinfection, provide the basis for evaluating the potential exposure of this contaminant to human. The data of this work also give insights to the formation of chlorinated drinking water disinfection by-products (DBPs).

  9. Progesterone and estradiol plasma levels in neonatally irradiated cycling rats

    SciTech Connect

    Freud, A.; Sod-Moriah, U.A. )

    1990-01-01

    Female rats which were exposed to a single low dose of gamma irradiation (6R or 15R) at the age of 8 days produce smaller litters when mature than untreated controls. The possibility that the impaired fertility resulted from altered ovarian activity as reflected by changes in plasma levels of progesterone or estardiol was investigated. Plasma levels of both steroids were determined throughout the day of proestrus. Progesterone level was also determined in 6R animals on the day of weaning. The maturity of such irradiated rats was assessed by observing the time of vaginal opening. The results indicated that the preovulatory peak of progesterone was delayed in the 6R rats whereas in the 15R group its levels were significantly lower. On the other hand no differences in estradiol plasma levels were noticed between the groups. The higher level of progesterone in the 6R animals was not evident on the day of weaning and was even in both groups, but vaginal opening in the irradiated rats was significantly delayed. The elevated level of progesterone might be responsible, among other endocrine changes, for the lower fertility of neonatally irradiated mature female rats.

  10. Fecal estradiol-17β and testosterone in prepubertal domestic cats.

    PubMed

    Faya, M; Carranza, A; Miotti, R; Ponchón, T; Furlan, P; Gobello, C

    2013-10-01

    The aim of this article was to describe the time course of prepubertal sexual steroids in domestic cats. Fourteen newborn kittens were followed up until puberty (physical, behavioral, and hormonal changes). Fecal testosterone [T; males] and E estradiol 17-β [E2; females] concentrations were analyzed by repeated measures ANOVA and two consecutive time windows (TWs) were used to compare changes in both male (postnatal weeks 1-4 vs. 5-14) and females (postnatal weeks 1-5 vs. 6-13). Puberty was achieved 14.3 ± 0.3 and 13.3 ± 0.4 weeks after birth in male and female cats, respectively. In both genders, during TW-1 fecal steroids concentrations were similar (males) or even higher (females) to that previously described for mature cats. Fecal T (P < 0.01) and E2 (P < 0.01) varied throughout the weeks. Differences were found when hormonal concentrations of TW-1 were compared with those of TW-2 both for male (61.4 ± 7.9 vs. 16.9 ± 2.2 ng/g; P < 0.01) and female (78.2 ± 12.5 vs. 11.2 ± 4.0 ng/g; P < 0.01) cats. It is concluded that in domestic cats there is a sexual steroid surge during the first 4 and 5 postnatal weeks in male and female animals, respectively.

  11. Estradiol protective role in atherogenesis through LDL structure modification

    NASA Astrophysics Data System (ADS)

    Papi, Massimiliano; Brunelli, Roberto; Ciasca, Gabriele; Maiorana, Alessandro; Maulucci, Giuseppe; Palmieri, Valentina; Parasassi, Tiziana; De Spirito, Marco

    2016-07-01

    Relevant physiological functions are exerted by circulating low density lipoprotein (LDL) as well as eventual pathological processes triggering atherogenesis. Modulation of these functions can well be founded on modifications of LDL structure. Given its large dimension, multicomponent organization and strong interactions between the protein apoB-100 and lipids, determining LDL 3D structure remains a challenge. We propose a novel quantitative physical approach to this complex biological problem. We introduce a three-component model, fitted to small angle x-ray scattering data on LDL maintained in physiological conditions, able to achieve a consistent 3D structure. Unexpected features include three distinct protein domains protruding out of a sphere, quite rough in its surface, where several core lipid areas are exposed. All LDL components are affected by 17-β-estradiol (E2) binding to apoB-100. Mostly one of the three protruding protein domains, dramatically reducing its presence on the surface and with a consequent increase of core lipids’ exposure. This result suggests a structural basis for some E2 protecting roles and LDL physiological modifications.

  12. Norethindrone acetate and estradiol-induced endometrial hyperplasia.

    PubMed

    Kurman, R J; Félix, J C; Archer, D F; Nanavati, N; Arce, J; Moyer, D L

    2000-09-01

    To identify the lowest effective continuous dose of norethindrone acetate that significantly reduces 12-month incidence of endometrial hyperplasia associated with unopposed 17beta-estradiol (E2), 1 mg. In a double-masked, randomized, multicenter study, 1176 healthy postmenopausal women 45 years of age or older without evidence of endometrial abnormalities were given 12 months of treatment with unopposed E2, 1 mg, or continuous-combined regimens of E2, 1 mg, and norethindrone acetate, 0.1 mg, 0.25 mg, or 0.5 mg. Endometrial histology was evaluated at the end of the treatment period. Continuous-combined E2-norethindrone acetate regimens significantly reduced 12-month incidence of endometrial hyperplasia compared with unopposed E2 1 mg (P <.001). Endometrial hyperplasia occurred in 14.6% of women treated with unopposed E2 1 mg, whereas in all continuous-combined groups, the rate decreased to less than 1%. Among patients who received E2-norethindrone acetate 0.1 mg, incidence was 0.8%; among those who received 0.25 mg and 0.5 mg, it was 0.4%. Continuous norethindrone acetate at doses as low as 0.1 mg combined with E2 1 mg effectively negated risk for endometrial hyperplasia associated with unopposed E2 1 mg, at least for the first year of therapy.

  13. Ethinyl estradiol and levonorgestrel in a transdermal contraceptive delivery system.

    PubMed

    Sriprasert, Intira; Stanczyk, Frank Z; Archer, David F

    2015-01-01

    The new transdermal contraceptive delivery system (TCDS) developed by Agile Therapeutics containing ethinyl estradiol and levonorgestrel (EE/LNG) is a reversible contraceptive method that maintains stable serum levels of both estrogen and progestin, and has efficacy similar to that of combination oral contraceptives (COC). We provided information of this new TCDS compared with the only TCDS available on the market that contains EE and norelgestromin, and has a higher EE exposure than a COC with 35 µg of EE potentially increasing the risk of venous thromboembolism. The article will summarize finding from clinical studies Phase I, II and III of EE/LNG TCDS. The development of the lower dose EE/LNG TCDS has demonstrated less EE exposure. The serum levels of EE and LNG were stable and comparable between various application sites and daily life conditions. Moreover, the EE/LNG TCDS showed comparable efficacy among obese and non-obese users. However, the Pearl index of this EE/LNG TCDS is questionable and the problem of compliance is a potential confounder of the results. The current Phase III efficacy study will contribute to a further evaluation of compliance and efficacy and will be completed in 2016.

  14. Transdermal 17-beta estradiol replacement therapy reduces megakaryocyte GPVI expression.

    PubMed

    Geng, Hongquan; Zhang, Hui; Zhang, Wei; Nieswandt, Bernhard; Bray, Paul F; Leng, Xinghong

    2008-01-01

    The platelet-collagen interaction is a critical early event in arterial thrombus formation, and platelet GPVI is the major activating receptor for collagen. We have previously used a mouse model to demonstrate that the estrogen effects on platelets depend upon the agonist, estrogen formulation and route of administration. In the current study we used a model of transdermal estradiol (E2) administration to ovariectomized mice to address the potential inhibitory effects of E2 on platelet GPVI. Platelet GPVI expression was reduced after transdermal E2 replacement therapy (p

  15. Effect of oral contraceptives containing estradiol and nomegestrol acetate or ethinyl-estradiol and chlormadinone acetate on primary dysmenorrhea.

    PubMed

    Grandi, Giovanni; Napolitano, Antonella; Xholli, Anjeza; Tirelli, Alessandra; Di Carlo, Costantino; Cagnacci, Angelo

    2015-10-01

    To study the three cycles effect on primary dysmenorrhea of the monophasic 24/4 estradiol/nomegestrol acetate (E2/NOMAC) and of the 21/7 ethinyl-estradiol/chlormadinone acetate (EE/CMA) oral contraceptive. The tolerability and the effect of both preparations on metabolism and health-related quality of life were also evaluated. Prospective observational cohort study. Tertiary gynecologic center for pelvic pain. Subjects with primary dysmenorrhea requiring an oral contraceptive, who spontaneously selected either E2/NOMAC (n = 20) or EE/CMA (n = 20). Visual Analogue Scale (VAS) score for dysmenorrhea, Short Form-36 questionnaire for health-related quality of life, lipoproteins and days of menstrual bleeding (withdrawal bleeding during oral contraceptive). Mean age and body mass index (BMI) were similar between the two groups. The final analysis was performed on 34 women, 15 in E2/NOMAC and 19 in EE/CMA group. Compliance with treatment was significantly higher with EE/CMA (100%) than E2/NOMAC (75%) (p = 0.02). Both treatments significantly (p < 0.0001) reduced VAS of primary dysmenorrhea, similarly (E2/NOMAC by a mean of 74.7%, EE/CMA by a mean of 78.4%; p = 0.973). Only E2/NOMAC significantly increased SF-36 score (p = 0.001), both in physical (p = 0.001) and mental domains (p = 0.004). The mean number of days of menstrual bleeding was significantly reduced in E2/NOMAC group (from 4.86 ± 1.20 d to 2.64 ± 1.59 d, p = 0.0005 versus baseline, p = 0.007 versus EE/CMA group). BMI did not vary in either group. E2/NOMAC did not change lipoproteins and apoproteins while EE/CMA increased total cholesterol (p = 0.0114), HDL-cholesterol (p = 0.0008), triglycerides (p = 0.002), apoprotein-A1 (Apo-A1; p = 0.0006) and apopoprotein-B (Apo-B; p = 0.008), decreasing LDL/HDL ratio (p = 0.024). Both oral contraceptives reduced similarly primary dysmenorrhea, with E2/NOMAC also reducing withdrawal bleedings and

  16. Distinct Epidermal Keratinocytes Respond to Extremely Low-Frequency Electromagnetic Fields Differently

    PubMed Central

    Huang, Chao-Ying; Chuang, Chun-Yu; Shu, Wun-Yi; Chang, Cheng-Wei; Chen, Chaang-Ray; Fan, Tai-Ching; Hsu, Ian C.

    2014-01-01

    Following an increase in the use of electric appliances that can generate 50 or 60 Hz electromagnetic fields, concerns have intensified regarding the biological effects of extremely low-frequency electromagnetic fields (ELF-EMFs) on human health. Previous epidemiological studies have suggested the carcinogenic potential of environmental exposure to ELF-EMFs, specifically at 50 or 60 Hz. However, the biological mechanism facilitating the effects of ELF-EMFs remains unclear. Cellular studies have yielded inconsistent results regarding the biological effects of ELF-EMFs. The inconsistent results might have been due to diverse cell types. In our previous study, we indicated that 1.5 mT, 60 Hz ELF-EMFs will cause G1 arrest through the activation of the ATM-Chk2-p21 pathway in human keratinocyte HaCaT cells. The aim of the current study was to investigate whether ELF-EMFs cause similar effects in a distinct epidermal keratinocyte, primary normal human epidermal keratinocytes (NHEK), by using the same ELF-EMF exposure system and experimental design. We observed that ELF-EMFs exerted no effects on cell growth, cell proliferation, cell cycle distribution, and the activation of ATM signaling pathway in NHEK cells. We demonstrated that the 2 epidermal keratinocytes responded to ELF-EMFs differently. To further validate this finding, we simultaneously exposed the NHEK and HaCaT cells to ELF-EMFs in the same incubator for 168 h and observed the cell growths. The simultaneous exposure of the two cell types results showed that the NHEK and HaCaT cells exhibited distinct responses to ELF-EMFs. Thus, we confirmed that the biological effects of ELF-EMFs in epidermal keratinocytes are cell type specific. Our findings may partially explain the inconsistent results of previous studies when comparing results across various experimental models. PMID:25409520

  17. Distinct epidermal keratinocytes respond to extremely low-frequency electromagnetic fields differently.

    PubMed

    Huang, Chao-Ying; Chuang, Chun-Yu; Shu, Wun-Yi; Chang, Cheng-Wei; Chen, Chaang-Ray; Fan, Tai-Ching; Hsu, Ian C

    2014-01-01

    Following an increase in the use of electric appliances that can generate 50 or 60 Hz electromagnetic fields, concerns have intensified regarding the biological effects of extremely low-frequency electromagnetic fields (ELF-EMFs) on human health. Previous epidemiological studies have suggested the carcinogenic potential of environmental exposure to ELF-EMFs, specifically at 50 or 60 Hz. However, the biological mechanism facilitating the effects of ELF-EMFs remains unclear. Cellular studies have yielded inconsistent results regarding the biological effects of ELF-EMFs. The inconsistent results might have been due to diverse cell types. In our previous study, we indicated that 1.5 mT, 60 Hz ELF-EMFs will cause G1 arrest through the activation of the ATM-Chk2-p21 pathway in human keratinocyte HaCaT cells. The aim of the current study was to investigate whether ELF-EMFs cause similar effects in a distinct epidermal keratinocyte, primary normal human epidermal keratinocytes (NHEK), by using the same ELF-EMF exposure system and experimental design. We observed that ELF-EMFs exerted no effects on cell growth, cell proliferation, cell cycle distribution, and the activation of ATM signaling pathway in NHEK cells. We demonstrated that the 2 epidermal keratinocytes responded to ELF-EMFs differently. To further validate this finding, we simultaneously exposed the NHEK and HaCaT cells to ELF-EMFs in the same incubator for 168 h and observed the cell growths. The simultaneous exposure of the two cell types results showed that the NHEK and HaCaT cells exhibited distinct responses to ELF-EMFs. Thus, we confirmed that the biological effects of ELF-EMFs in epidermal keratinocytes are cell type specific. Our findings may partially explain the inconsistent results of previous studies when comparing results across various experimental models.

  18. Applied AC and DC magnetic fields cause alterations in the mitotic cycle of early sea urchin embryos

    SciTech Connect

    Levin, M.; Ernst, S.G.

    1995-09-01

    This study demonstrates that exposure to 60 Hz magnetic fields (3.4--8.8 mt) and magnetic fields over the range DC-600 kHz (2.5--6.5 mT) can alter the early embryonic development of sea urchin embryos by inducing alterations in the timing of the cell cycle. Batches of fertilized eggs were exposed to the fields produced by a coil system. Samples of the continuous cultures were taken and scored for cell division. The times of both the first and second cell divisions were advanced by ELF AC fields and by static fields. The magnitude of the 60 Hz effect appears proportional to the field strength over the range tested. the relationship to field frequency was nonlinear and complex. For certain frequencies above the ELF range, the exposure resulted in a delay of the onset of mitosis. The advance of mitosis was also dependent on the duration of exposure and on the timing of exposure relative to fertilization.

  19. Effects of electromagnetic fields (EMF) on the chemiluminescence (CL) of murine peritoneal exudate cells

    SciTech Connect

    Caren, L.D. )

    1992-02-26

    Stimulated PEC generate microbicidal free oxygen radicals which are potentially mutagenic and possibly carcinogenic. The effects of combined alternating electric and magnetic fields on oxygen radical production were measured in this study. A Helmholtz coil and parallel plate electrodes were utilized to provide uniform field characteristics. Effects were studied at combined field frequencies of 60, 600, and 6,000 Hz. Thioglycollate-elicited PEC were exposed to EMF or placed in a far corner of the lab (controls). Following the addition of zymosan, luminol-enhanced CL was measured. No differences in CL were found for exposures to 60 Hz for 18 hr; 600 Hz for 10 hr; or 6,000 Hz for 0.75 hr. PEC exposed to 6,000 Hz for 11 hr showed a 25% increase in CL over control PEC. At 600 and 6,000 Hz, the temperature of the air and a dish of saline in the EMF apparatus was 26C, vs. 25C where the controls were kept. At 60 Hz, there was no temperature difference. These preliminary experiments indicate that under these conditions, EMF fields do not have a significant effect on this immune function.

  20. Recognition and effective degradation of 17beta-estradiol by anti-estradiol-antibody-immobilized TiO(2) nanoparticles.

    PubMed

    Ogino, Chiaki; Kanehira, Koki; Sasai, Ryosuke; Sonezaki, Shuji; Shimizu, Nobuaki

    2007-10-01

    Polyelectrolyte polyacrylic acid (PAA), used in the chemical modification of titanium dioxide (TiO(2)) nanoparticles, allows TiO(2) nanoparticles to remain in suspension at neutral pH. The anti-17beta-estradiol (E2) antibody was immobilized on PAA-modified TiO(2) (PAA-TiO(2)) nanoparticles via covalent bonding between the carboxylic acid of PAA and the amino group of the antibody. The anti-E2-antibody-immobilized TiO(2) (E2Ab-PAA-TiO(2)) nanoparticles can form a suspension at neutral pH, with a particle size of less than 100 nm. The E2-PAA-TiO(2) nanoparticles caused the photocatalytic degradation of a typical TiO(2) substrate, methylene blue. The anti-E2 antibody immobilized on the TiO(2) surface recognized and bound E2 in the solution, thereby improving the efficiency of E2 degradation compared with that of PAA-TiO(2) nanoparticles. These results demonstrate that the E2Ab-PAA-TiO(2) nanoparticles developed in this study can be used in water treatment technology. Furthermore, this strategy of immobilizing proteins on nanoscale TiO(2) particles creates new applications not only in the treatment of environmental waste, but also in medical and public sanitation processes.

  1. Delineation of electric and magnetic field effects of extremely low frequency electromagnetic radiation on transcription

    SciTech Connect

    Greene, J.J.; Skowronski, W.J.; Mullins, J.M.; Nardone, R.M.; Penafiel, M.; Meister, R. )

    1991-01-31

    The relative effects of the electric and magnetic field components of extremely low frequency electromagnetic radiation (ELF) on transcription were examined in human leukemia HL-60 cells. Delineation of the individual field contributions was achieved by irradiating cells in separate concentric compartments of a culture dish within a solenoid chamber. This exposure system produced a homogeneous magnetic field with a coincident electric field whose strength varied directly with distance from the center of the culture dish. Irradiation of HL-60 cells with sine wave ELF at 60 Hz and a field strength of 10 Gauss produced a transient increase in the transcriptional rates which reached a maximum of 50-60% enhancement at 30-120 minutes of irradiation and declined to near basal levels by 18 hours. Comparison of transcription responses to ELF of cells in different concentric compartments revealed that the transcriptional effects were primarily the result of the electric field component with little or no contribution from the magnetic field.

  2. Effects of chronic estradiol treatment on the thyroid gland structure and function of ovariectomized rats.

    PubMed

    Abdel-Dayem, Menna M; Elgendy, Mohamed S

    2009-08-30

    Estrogen therapy is widely used nowadays in women to treat many postmenopausal symptoms but it may have some undesirable effects due to multiple organs affection. So, the aim of this study was to determine the effects of chronic estradiol treatment on the structure and function of the thyroid gland in ovarictomized rats as a model simulating menopause. Thirty adult female Wistar rats divided into three groups were used in this study; the first group was sham-operated, while the second and third groups were ovariectomized. The first and second groups were injected with olive oil while the third group was injected with estradiol dipropionate daily for three months, after that; hormonal assay for T3, T4, TSH and specimens of the thyroid were taken and processed to be examined by light and electron microscopy. The results of this study revealed that serum levels of T3 and T4 decreased in ovariectomized animals and significantly increased after estradiol treatment, while TSH increased in ovariectomized animals and decreased with estradiol treatment. Histological and morphometric study in ovariectomized group revealed marked accumulation of colloid in follicular lumens with decreased epithelial height in addition to increased connective tissue amount. After estradiol treatment the follicles became smaller in size, having small amount of colloid with increased epithelial height in addition to decreased connective tissue content. Ultrastructural study supported these results in addition to the presence of large amount of intracytoplasmic colloid vesicles after estradiol treatment. Low estrogen level may lead to mild thyroidal hypofunction while estradiol treatment may lead to hyperactivity so it should be used very cautiously in the treatment of postmenopausal symptoms to avoid its undesirable stimulatory effect on the thyroid.

  3. Comparison of Two Methods of Estradiol Replacement: their Physiological and Behavioral Outcomes

    PubMed Central

    Mosquera, Laurivette; Shepherd, Luz; Torrado, Aranza I; Torres-Diaz, Yvonne M; Miranda, Jorge D; Segarra, Annabell C

    2016-01-01

    Fluctuating sex steroids during the estrous or menstrual cycle of mammalian females make it difficult to determine their role on behaviors and physiology. To avoid this, many investigators ovariectomize their animals and administer progesterone, estradiol or a combination of both. Several different strategies are used to administer estradiol, which confounds interpretation of results. This study compared two methods of estradiol replacement implants: Silastic tubes filled with crystalline estradiol benzoate (E2) and commercially available estradiol benzoate pellets. Implants were placed subcutaneously in adult ovariectomized (OVX) rats and blood samples obtained weekly. Control OVX rats received empty Silastic tubes or placebo pellets. Our data shows that E2 plasma levels from rats with Silastic implants peaked after one week and decreased slowly thereafter. In contrast, plasma E2 from commercial pellets peaked after two weeks, increasing and decreasing over time. To validate hormone release, body weight was monitored. All E2 treated animals maintained a similar body weight over the four weeks period whereas an increase in body weight over time was observed in the OVX group that received empty implants, confirming E2 release and supporting the role of E2 in the regulation of body weight. Furthermore, the effects of E2 on basal locomotor activity were assessed using animal activity cages. Results showed no difference between E2 and control group in several locomotor activities. These results indicate that Silastic implants achieve more stable plasma estradiol levels than pellets and thus are a better alternative for studies of estradiol on brain function and behavior. PMID:26962471

  4. Estradiol levels modulate brain activity and negative responses to psychosocial stress across the menstrual cycle.

    PubMed

    Albert, Kimberly; Pruessner, Jens; Newhouse, Paul

    2015-09-01

    Although ovarian hormones are thought to have a potential role in the well-known sex difference in mood and anxiety disorders, the mechanisms through which ovarian hormone changes contribute to stress regulation are not well understood. One mechanism by which ovarian hormones might impact mood regulation is by mediating the effect of psychosocial stress, which often precedes depressive episodes and may have mood consequences that are particularly relevant in women. In the current study, brain activity and mood response to psychosocial stress was examined in healthy, normally cycling women at either the high or low estradiol phase of the menstrual cycle. Twenty eight women were exposed to the Montreal Imaging Stress Task (MIST), with brain activity determined through functional magnetic resonance imaging, and behavioral response assessed with subjective mood and stress measures. Brain activity responses to psychosocial stress differed between women in the low versus high estrogen phase of the menstrual cycle: women with high estradiol levels showed significantly less deactivation in limbic regions during psychosocial stress compared to women with low estradiol levels. Additionally, women with higher estradiol levels also had less subjective distress in response to the MIST than women with lower estradiol levels. The results of this study suggest that, in normally cycling premenopausal women, high estradiol levels attenuate the brain activation changes and negative mood response to psychosocial stress. Normal ovarian hormone fluctuations may alter the impact of psychosocially stressful events by presenting periods of increased vulnerability to psychosocial stress during low estradiol phases of the menstrual cycle. This menstrual cycle-related fluctuation in stress vulnerability may be relevant to the greater risk for affective disorder or post-traumatic stress disorder in women. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Peripheral microvascular vasodilatory response to estradiol and genistein in women with insulin resistance

    PubMed Central

    Wenner, Megan M.; Taylor, Hugh S.; Stachenfeld, Nina S.

    2015-01-01

    Objective Estradiol enhances vasodilation in healthy women, but vascular effects of the phytoestrogen genistein are still under investigation. Insulin resistance (IR) compromises microvascular function. We therefore examined the interaction of estradiol, genistein, and IR on microvascular vasodilatory responsiveness. Methods We hypothesized that estradiol and genistein increase microvascular vasodilation in healthy women (control, n=8, 23±2 yr, BMI 25.9±2.9 kg/m2) but not in women with IR (n=7, 20±1 yr, BMI 27.3±3.0 kg/m2). We used the cutaneous circulation as a model of microvascular vasodilatory function. We determined cutaneous vascular conductance (CVC) with laser Doppler flowmetry and beat-to-beat blood pressure during local cutaneous heating (42°C) with estradiol or genistein microdialysis perfusions. Because heat induced vasodilation is primarily an NO mediated response, we examined microvascular vasodilation with and without L-NMMA. Results In control women, estradiol enhanced CVC (94.4±2.6 % vs. saline 81.6±4.2 % CVCmax, P<0.05), which was reversed with L-NMMA (80.9±7.8 % CVCmax, P<0.05), but genistein did not affect vasodilation. Neither estradiol nor genistein altered CVC in IR, although L-NMMA attenuated CVC during genistein. Conclusions Our study does not support improved microvascular responsiveness during genistein exposure in healthy young women, and demonstrates that neither estradiol nor genistein improve microvascular vasodilatory responsiveness in women with IR. PMID:25996650

  6. Detection of estradiol at an electrochemical immunosensor with a Cu UPD|DTBP-Protein G scaffold.

    PubMed

    Liu, Xiaoqiang; Wang, Xinhai; Zhang, Jiamei; Feng, Heqing; Liu, Xiuhua; Wong, Danny K Y

    2012-05-15

    A copper monolayer was formed on a gold electrode surface via underpotential deposition (UPD) method to construct a Cu UPD|DTBP-Protein G immunosensor for the sensitive detection of 17β-estradiol. Copper UPD monolayer can minimize the non-specific adsorption of biological molecules on the immunosensor surface and enhance the binding efficiency between immunosensor surface and thiolated Protein G. The crosslinker DTBP (Dimethyl 3,3'-dithiobispropionimidate · 2HCl) has strong ability to immobilize Protein G molecules on the electrode surface and the immobilized Protein G provides an orientation-controlled binding of antibodies. A monolayer of propanethiol was firstly self-assembled on the gold electrode surface, and a copper monolayer was deposited via UPD on the propanethiol modified electrode. Propanethiol monolayer helps to stabilize the copper monolayer by pushing the formation and stripping potentials of the copper UPD monolayer outside the potential range in which copper monolayer can be damaged easily by oxygen in air. A droplet DTBP-Protein G was then applied on the modified electrode surface followed by the immobilization of estradiol antibody. Finally, a competitive immunoassay was conducted between estradiol-BSA (bovine serum albumin) conjugate and free estradiol for the limited binding sites of estradiol antibody. Square wave voltammetry (SWV) was employed to monitor the electrochemical reduction current of ferrocenemethanol and the SWV current decreased with the increase of estradiol-BSA conjugate concentration at the immunosensor surface. Calibration of immunosensors in waste water samples spiked with 17β-estradiol yielded a linear response up to ≈ 2200 pg mL(-1), a sensitivity of 3.20 μA/pg mL(-1) and a detection limit of 12 pg mL(-1). The favorable characteristics of the immunosensors such as high selectivity, sensitivity and low detection limit can be attributed to the Cu UPD|DTBP-Protein G scaffold.

  7. Regulation of prolactin synthesis in vitro by estrogenic and antiestrogenic derivatives of estradiol and estrone.

    PubMed

    Jordan, V C; Koch, R

    1989-04-01

    The estrogenic and antiestrogenic activities of derivatives of estradiol and estrone were determined in vitro using the ability of primary cultures of immature rat pituitary cells to synthesize PRL. Estradiol derivatives were the most potent estrogens in the assay. Large ethinyl substitutions in the 17 alpha position generally caused a decrease in estrogenic potency (up to 1000-fold). The 3 phenolic hydroxyl was important, but not essential, for the estrogenic activity of the estradiol molecule. Estratriene was approximately 1000 times less potent than estradiol. However, significant estrogenic activity was observed with the compound anordin (EC50, 8 x 10(-9) M), which could potentially be converted to a dihydroxylated derivative but without an aromatic A ring. Similarly, the steroid androst-5-ene-3,17-diol was weakly estrogenic (EC50, 3 x 10(-8) M). Steriods with a ketone in the A and D rings were generally inactive as estrogens and antiestrogens. Estradiol derivatives with 17 beta amines were only weak estrogens. Estrone derivatives were less active than the corresponding estradiol derivatives. 4-Nitromethoxyestrone exhibited weak antiestrogenic properties; however, 4-nitroestrone and methoxyestrone were both estrogens. The reason for the antiestrogenic properties of 4-nitromethoxyestrone is obscure, as the compound does not have structural features similar to those of known nonsteroidal antiestrogens. Minor alterations to the estradiol molecule at the 11 beta (OH) or 6 (ketone) position had little effect on estrogenic potency; however, large substitutions at the 11 beta (RU 39,411) or 7 alpha (ICI 164384) position produced antiestrogenic compounds. RU 39,411 was approximately 10 times more active as an antiestrogen than 4-hydroxytamoxifen, whereas ICI 164,384 was approximately 10 times less active than 4-hydroxytamoxifen. A series of hypothetical models is proposed that could explain the antiestrogenic properties of RU 39,411 and ICI 164,384 by an interaction

  8. Thalidomide does not alter the pharmacokinetics of ethinyl estradiol and norethindrone.

    PubMed

    Trapnell, C B; Donahue, S R; Collins, J M; Flockhart, D A; Thacker, D; Abernethy, D R

    1998-12-01

    To evaluate the effect of thalidomide on the plasma pharmacokinetics of ethinyl estradiol (INN, ethinylestradiol) and norethindrone (INN, norethisterone). Ten women who had undergone surgical sterilization were enrolled in an open-label crossover study conducted in the Georgetown University Clinical Research Center. The pharmacokinetics of single doses of 0.07 mg ethinyl estradiol and 2 mg norethindrone were measured at baseline and after 3 weeks of 200 mg thalidomide. Compliance with the thalidomide regimen was assessed with use of Medication Event Monitoring System (MEMS) caps. No changes were observed in the pharmacokinetics of ethinyl estradiol or norethindrone with thalidomide therapy. The mean +/- SD area under the plasma concentration-time curve (AUC0-infinity) for ethinyl estradiol was 6580 +/- 1100 ng.h/L at baseline and 5970 +/- 1560 ng.h/L after the thalidomide regimen (paired t test, P > .05). The values for norethindrone were 103 +/- 54 micrograms.h/L and 107 +/- 58 micrograms.h/L (paired t test, P > .05). No changes were observed for other pharmacokinetic parameters assessed for either ethinyl estradiol or norethindrone. No accumulation of thalidomide was seen after 21 days of therapy: day 1 AUC0-infinity 41.1 +/- 13.9 micrograms.h/mL; day 21 AUC0-infinity 59.6 +/- 27.3 micrograms.h/mL (paired t test, P > .05). No changes were observed for other pharmacokinetic parameters assessed for thalidomide between days 1 and 21. Thalidomide was well tolerated but caused variable degrees of sedation. The average thalidomide compliance rate was 97%. The pharmacokinetics of thalidomide do not change with 3 weeks of daily dosing. Thalidomide does not alter the pharmacokinetics of ethinyl estradiol or norethindrone. Therefore there is no drug interaction between thalidomide and these 2 drugs. The efficacy of oral contraceptives containing ethinyl estradiol and norethindrone should not be affected by concomitant thalidomide therapy.

  9. 17β-estradiol upregulates oxytocin and the oxytocin receptor in C2C12 myotubes

    PubMed Central

    Berio, Enrica; Starvaggi Cucuzza, Laura; Biolatti, Bartolomeo; Cannizzo, Francesca Tiziana

    2017-01-01

    Background The endocrinology of skeletal muscle is highly complex and many issues about hormone action in skeletal muscle are still unresolved. Aim of the work is to improve our knowledge on the relationship between skeletal muscle and 17β-estradiol. Methods The skeletal muscle cell line C2C12 was treated with 17β-estradiol, the oxytocin peptide and a combination of the two hormones. The mRNA levels of myogenic regulatory factors, myosin heavy chain, oxytocin, oxytocin receptor and adipogenic factors were analysed in C2C12 myotubes. Results It was demonstrated that C2C12 myoblasts and myotubes express oxytocin and its receptor, in particular the receptor levels physiologically increase in differentiated myotubes. Myotubes treated with 17β-estradiol overexpressed oxytocin and oxytocin receptor genes by approximately 3- and 29-fold, respectively. A decrease in the expression of fatty acid binding protein 4 (0.62-fold), a fat metabolism-associated gene, was observed in oxytocin-treated myotubes. On the contrary, fatty acid binding protein 4 was upregulated (2.66-fold) after the administration of the combination of 17β-estradiol and oxytocin. 17β-estradiol regulates oxytocin and its receptor in skeletal muscle cells and they act in a synergic way on fatty acid metabolism. Discussion Oxytocin and its receptor are physiologically regulated along differentiation. 17β-estradiol regulates oxytocin and its receptor in skeletal muscle cells. 17β-estradiol and oxytocin act in a synergic way on fatty acid metabolism. A better understanding of the regulation of skeletal muscle homeostasis by estrogens and oxytocin peptide could contribute to increase our knowledge of muscle and its metabolism. PMID:28382233

  10. Estradiol Uptake in a Combined Magnetic Ion Exchange - Ultrafiltration (MIEX-UF) Process During Water Treatment.

    PubMed

    Imbrogno, Alessandra; Biscarat, Jennifer; Schafer, Andrea Iris

    2017-01-01

    Estrogens and their synthetic analogues are widely used as pharmaceuticals. Upon oral administration these drugs are eventually excreted via urine. The persistence of these pharmaceuticals and inefficient removal by water treatment lead to accumulation in surface water and effluents with negative effects for aquatic life and human health. In this study, the uptake of estradiol by a combined magnetic ion exchange resin - ultrafiltration process (MIEX-UF) was investigated. This is a relatively common process used in drinking water treatment for the removal of natural organic matter. However, uptake of micropollutants, such as steroidal pharmaceuticals, may occur as a side effect of water treatment due to the high affinity for polymeric materials. To elucidate the mechanism governing estradiol partitioning between water, resin and membrane, the influence of different parameters, such as pH, humic acid concentration and membrane molecular-weight-cut-off (MWCO) was studied. Humic acid concentration and pH affected estradiol uptake most. At pH 11 the most significant increase of estradiol uptake was observed for MIEX-UF process (30 ng/g corresponding to 80%) compared with individual UF (17 ng/g corresponding to 12%). The presence of humic acid slightly reduced estradiol uptake at pH 11 (about 55%) due to competition for the ion exchange binding sites. Results demonstrated that the uptake of estradiol, which is amongst the most potent EDCs detected in surface water, in the MIEX-UF process can reach significant quantities (30 ng/g of resin) leading to uncontrolled accumulation of this micropollutant during drinking water treatment. This study gives a novel contribution in the understanding the mechanism of the unanticipated accumulation of pharmaceuticals, such as estradiol, in the drinking water treatment process. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. Behavioral effects of endogenous or exogenous estradiol and progesterone on cocaine sensitization in female rats

    PubMed Central

    Souza, M.F.; Couto-Pereira, N.S.; Freese, L.; Costa, P.A.; Caletti, G.; Bisognin, K.M.; Nin, M.S.; Gomez, R.; Barros, H.M.T.

    2014-01-01

    Cocaine sensitization is a marker for some facets of addiction, is greater in female rats, and may be influenced by their sex hormones. We compared the modulatory effects of endogenous or exogenous estradiol and progesterone on cocaine-induced behavioral sensitization in 106 female rats. Ovariectomized female rats received progesterone (0.5 mg/mL), estradiol (0.05 mg/mL), progesterone plus estradiol, or the oil vehicle. Sham-operated control females received oil. Control and acute subgroups received injections of saline, while the repeated group received cocaine (15 mg/kg, ip) for 8 days. After 10 days, the acute and repeated groups received a challenge dose of cocaine, after which locomotion and stereotypy were monitored. The estrous cycle phase was evaluated and blood was collected to verify hormone levels. Repeated cocaine treatment induced overall behavioral sensitization in female rats, with increased locomotion and stereotypies. In detailed analysis, ovariectomized rats showed no locomotor sensitization; however, the sensitization of stereotypies was maintained. Only females with endogenous estradiol and progesterone demonstrated increased locomotor activity after cocaine challenge. Estradiol replacement enhanced stereotyped behaviors after repeated cocaine administration. Cocaine sensitization of stereotyped behaviors in female rats was reduced after progesterone replacement, either alone or concomitant with estradiol. The behavioral responses (locomotion and stereotypy) to cocaine were affected differently, depending on whether the female hormones were of an endogenous or exogenous origin. Therefore, hormonal cycling appears to be an important factor in the sensitization of females. Although estradiol increases the risk of cocaine sensitization, progesterone warrants further study as a pharmacological treatment in the prevention of psychostimulant abuse. PMID:24878606

  12. Estradiol inhibits Ca2+ and K+ channels in smooth muscle cells from pregnant rat myometrium.

    PubMed

    Okabe, K; Inoue, Y; Soeda, H

    1999-07-02

    The purpose of this study was to investigate the actions of 17beta-estradiol on the electrical activity of pregnant rat myometrium. The longitudinal layer of the myometrium was dissected from pregnant rats (17 to 19 days of gestation), and single cells were isolated by enzymatic digestion. Calcium currents and potassium currents were recorded by the whole-cell voltage-clamp method, and the single calcium-dependent potassium current was recorded by the outside-out patch-clamp method. The effects of 17beta-estradiol on these currents were investigated. When a myometrial cell was held at -50 mV, depolarization to a potential more positive than -30 mV produced an inward current followed by a slowly developing outward current. Application of tetraethylammonium inhibited the outward current while the inward current was completely abolished in a calcium-free solution. Estradiol at high concentrations (> 3 microM) inhibited both inward and outward currents in a voltage-dependent manner. Removal of estradiol restored the amplitude of the outward but not of the inward current. Estradiol (30 microM) also inhibited the activity of single calcium-dependent potassium channels without changing single channel conductance. In conclusion, estradiol at high concentrations inhibited: (1) voltage-dependent calcium, (2) calcium-dependent potassium and (3) voltage-dependent potassium currents. These actions of estradiol would prevent action potential generation and after-hyperpolarizations. Suppression of the after-hyperpolarization might further prevent spike generation due to slowing of the calcium channel's recovery from the inactivated state.

  13. Vaginal estradiol use and the risk for cardiovascular mortality.

    PubMed

    Mikkola, Tomi S; Tuomikoski, Pauliina; Lyytinen, Heli; Korhonen, Pasi; Hoti, Fabian; Vattulainen, Pia; Gissler, Mika; Ylikorkala, Olavi

    2016-04-01

    Does the use of post-menopausal vaginal estradiol (VE) affect the mortality risk for coronary heart disease (CHD) and stroke. The use of VE reduces the risk for cardiovascular mortality. A growing number of women use VE for post-menopausal genitourinary symptoms. Although this therapy is intended to have only local effects, estrogen is absorbed into the blood circulation and thus VE use may also have systemic effects. We studied a nationwide cohort in Finland 1994-2009 during which post-menopausal women (n = 195 756) initiated the use of VE (age [mean ± SD] 65.7 ± 10.9 years). Follow-up data gathered 1.4 million women-years and we assessed the mortality risk due to CHD (n= 9656) or stroke (n = 4294). The mortality risk in VE users was compared with that in the age-matched background population (standardized mortality ratio; [SMR]; 95% confidence interval) and related to various durations of exposure to VE (1 to ≤3, >3 to ≤5, >5 to ≤10 and >10 years). The use of VE was accompanied by decreases in the risk for CHD and stroke death. The risk reduction for CHD death was highest for >3 to ≤5 years exposure (SMR 0.64; 0.57-0.70) and for stroke for >5 to ≤10 years exposure (SMR 0.64; 0.57-0.72). The risk reductions for both CHD and stroke mortality were detected in all age groups with the highest risk reduction being in women aged 50-59 years (SMR 0.43; 0.19-0.88 and SMR 0.21; 0.06-0.58, respectively). Our series lack a placebo arm and thus, may harbor a healthy woman bias. Moreover, data on clinical variables such as weight, smoking, blood pressure and family background were unobtainable for this study. Women using both VE and systemic hormone therapy (HT) were included in the comparator background population. This should not cause any significant error because the proportion of women using VE or other HT was modest (<10% in age-matched population) and because the use of systemic HT also reduces death risks in the same population. Our data cannot be directly

  14. The relationship between circulating estradiol and thyroid autoimmunity in males.

    PubMed

    Chailurkit, La-or; Aekplakorn, Wichai; Ongphiphadhanakul, Boonsong

    2014-01-01

    Although autoimmune thyroid disease is less common in males, it is unclear whether estrogen contributes to the difference in susceptibility among males. To examine whether circulating estradiol (E₂) is related to thyroid autoimmunity in males. One-thousand two-hundred and sixty-three males aged 15-94 years were studied. Serum levels of E₂, TSH receptor antibody (TRAb), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), free thyroxine (FT₄), and TSH were measured by ELISA. Circulating E₂ varied widely in males, ranging 18.4-403.7 pmol/l with a mean value of 136.2±51.7 pmol/l. E₂ increased with age (r=0.18, P<0.001). No relationship between E₂ and BMI was found. When comparing the difference in E₂ according to the test results of TRAb, TPOAb, and TgAb, it was found that E₂ was significantly higher in subjects with positive TRAb (TRAb positive, E₂=170.3±59.8 pmol/l; TRAb negative, E₂=134.0±50.6 pmol/l; P<0.001). No difference in E₂ was demonstrated according to the results of TPOAb or TgAb. Logistic regression analysis showed that E₂ was a determinant of positive TRAb, independent of age and BMI. There was no relationship between serum E₂ and TSH or FT₄. However, E₂ was negatively related to TSH (r=-0.45, P<0.01) in subjects whose TSH levels fell below the reference range (0.3-4.2 mIU/l). Higher circulating E₂ is related to thyroid autoimmunity in males as reflected by positive TRAb.

  15. Progesterone resistance in endometriosis: link to failure to metabolize estradiol.

    PubMed

    Bulun, Serdar E; Cheng, You-Hong; Yin, Ping; Imir, Gonca; Utsunomiya, Hiroki; Attar, Erkut; Innes, Joy; Julie Kim, J

    2006-03-27

    Endometriosis is the most common cause of pelvic pain and affects an estimated 5 million women in the US. The biologically active estrogen estradiol (E2) is the best-defined mitogen for the growth and inflammation processes in the ectopic endometriotic tissue that commonly resides on the pelvic organs. Progesterone and progestins may relieve pain by limiting growth and inflammation in endometriosis but a portion of patients with endometriosis and pelvic pain do not respond to treatment with progestins. Moreover, progesterone-induced molecular changes in the eutopic (intrauterine) endometrial tissue of women with endometriosis are either blunted or undetectable. These in vivo observations are indicative of resistance to progesterone action in endometriosis. The molecular basis of progesterone resistance in endometriosis may be related to an overall reduction in the levels of progesterone receptors (PRs) and the lack of the PR isoform named progesterone receptor B (PR-B). In normal endometrium, progesterone acts on stromal cells to induce secretion of paracrine factor(s). These unknown factor(s) act on neighboring epithelial cells to induce the expression of the enzyme 17beta-hydroxysteroid dehydrogenase type 2 (17beta-HSD-2), which metabolizes the biologically active estrogen E2 to estrone (E1). In endometriotic tissue, progesterone does not induce epithelial 17beta-HSD-2 expression due to a defect in stromal cells. The inability of endometriotic stromal cells to produce progesterone-induced paracrine factors that stimulate 17beta-HSD-2 may be due to the lack of PR-B and very low levels of progesterone receptor A (PR-A) observed in vivo in endometriotic tissue. The end result is deficient metabolism of E2 in endometriosis giving rise to high local concentrations of this local mitogen. The cellular and molecular mechanisms underlying progesterone resistance and failure to metabolize E2 in endometriosis are reviewed.

  16. Estradiol-induced gene expression in largemouth bass (Micropterus salmoides)

    USGS Publications Warehouse

    Bowman, C.J.; Kroll, K.J.; Gross, T.G.; Denslow, N.D.

    2002-01-01

    Vitellogenin (Vtg) and estrogen receptor (ER) gene expression levels were measured in largemouth bass to evaluate the activation of the ER-mediated pathway by estradiol (E2). Single injections of E2 ranging from 0.0005 to 5 mg/kg up-regulated plasma Vtg in a dose-dependent manner. Vtg and ER mRNAs were measured using partial cDNA sequences corresponding to the C-terminal domain for Vtg and the ligand-binding domain of ER?? sequences. After acute E2-exposures (2 mg/kg), Vtg and ER mRNAs and plasma Vtg levels peaked after 2 days. The rate of ER mRNA accumulation peaked 36-42 h earlier than Vtg mRNA. The expression window for ER defines the primary response to E2 in largemouth bass and that for Vtg a delayed primary response. The specific effect of E2 on other estrogen-regulated genes was tested during these same time windows using differential display RT-PCR. Specific up-regulated genes that are expressed in the same time window as Vtg were ERp72 (a membrane-bound disulfide isomerase) and a gene with homology to an expressed gene identified in zebrafish. Genes that were expressed in a pattern that mimics the ER include the gene for zona radiata protein ZP2, and a gene with homology to an expressed gene found in winter flounder. One gene for fibrinogen ?? was down-regulated and an unidentified gene was transiently up-regulated after 12 h of exposure and returned to basal levels by 48 h. Taken together these studies indicate that the acute molecular response to E2 involves a complex network of responses over time. ?? 2002 Elsevier Science Ireland Ltd. All rights reserved.

  17. Specific estradiol biosynthetic pathway in choriocarcinoma (JEG-3) cell line.

    PubMed

    Samson, Mélanie; Labrie, Fernand; Luu-The, Van

    2009-09-01

    Estradiol (E2) plays a crucial role in all reproduction processes. In the placenta, it is well recognized that E2 is synthesized from fetal dehydroepiandrosterone sulfate (DHEAS). However, there is some controversy about the biosynthetic pathway involved, some authors suggest that E2 is produced by aromatization of testosterone (T), while others suggest that E2 is produced by the conversion of estrone (E1) into E2 by type 1 17beta-HSD, subsequent to the aromatization of 4-androstenedione (4-dione) into E1. In the present report, using the precursor [(14)C]DHEA, inhibitors of steroidogenic enzymes (chemical inhibitors and siRNA) and a choriocarcinoma (JEG-3) cell line that expresses all the enzymes necessary to transform DHEA into E2, we could determine the sequential steps and the specific steroidogenic enzymes involved in the transformation of DHEA into E2. Quantification of mRNA expression levels using real-time PCR, strongly suggests that type 1 3beta-hydroxysteroid dehydrogenase (3beta-HSD1), aromatase and type 1 17beta-HSD (17beta-HSD1) that are highly expressed in JEG-3 cells are the enzymes responsible for the transformation of DHEA into E2. Analysis of the intermediates produced in the absence and presence of 3beta-HSD, aromatase and 17beta-HSD1 inhibitors permits to determine the following sequential steps: DHEA is transformed into 4-dione by 3beta-HSD1, then 4-dione is aromatized into E1 by aromatase and E1 is finally transformed into E2 by 17beta-HSD1. Our data are clearly in favor of the pathway in which the step of aromatization precedes the step of reduction by 17beta-HSD.

  18. Estradiol-progesterone interaction during the preparation of vaginal rings.

    PubMed

    Saleh, Saleh I; Khidr, Sayed H; Ahmed, Sayed M; Jackanicz, Theodore M; Nash, Harold A

    2003-02-01

    An unexpected enhanced release, in vitro, of estradiol (E2) was observed on the preparation of vaginal rings containing E2 and progesterone (P) in a silicone elastomer. The present work deals with exploring the reason(s) behind this enhanced E2 release. The effect of the ring design (i.e., putting P and E2 in the same compartment or in adjacent or separate compartments) was studied. The effects of the curing temperature as well as the curing time were also investigated. The possible interaction(s) between P and E2 on simple heating of their mixtures was investigated using infrared (IR), differential scanning calorimetry (DSC), and nuclear magnetic resonance (NMR) techniques. Also, the dissolution behavior of P, E2, and their mixture before and after heating was studied. The ring design, with respect to the position of the steroid layer(s), affected the release of P and E2 from the vaginal rings. Curing the rings at higher temperatures (>/=140 degrees C) for >/=30 min resulted in an enhanced release of the steroids, especially E2. The IR, DSC, phase diagram, and NMR results indicate that an interaction between P and E2, leading to the formation of a molecular complex, took place. It was concluded that putting P and E2 in the same compartment and curing by heating at a high temperature and for an extended time promoted this kind of interaction. The greater hydrophobicity of the interaction product, relative to that of E2, was considered the main reason behind the enhanced in vitro release of E2 from the vaginal rings.

  19. Transdermal Estradiol Treatment for Postpartum Depression: A Pilot Randomized Trial

    PubMed Central

    Wisner, Katherine L.; Sit, Dorothy K.Y.; Moses-Kolko, Eydie L.; Driscoll, Kara E.; Prairie, Beth; Stika, Catherine S.; Eng, Heather F.; Dills, John L; Luther, James F.; Wisniewski, Stephen R.

    2015-01-01

    Postpartum depression occurs in 14.5% of women in the first three months after birth. This study was an 8 week acute phase randomized trial with three cells (transdermal estradiol (E2), sertraline, and placebo) for the treatment of postpartum major depressive disorder. However, the study was stopped after batch analysis revealed that the E2 serum concentrations were lower than pre-study projections. This paper explores our experiences that will inform future investigations of therapeutic E2 use. Explanations for the low E2 concentrations were: 1) Study patch non-adhesion, which did not explain the low concentrations across the entire sample. 2) Ineffective transdermal patch preparations, although two different patch preparations were used and no significant main effect of patch type on E2 concentrations was found. 3) Obesity, at study entry, E2-treated women had mean ± SD BMI=32.9 ±7.4. No pharmacokinetic data comparing E2 concentrations from transdermal patches in obese women vs. normal weight controls are available. 4) Induction of Cytochrome P450 (CYP450) 3A4 and other E2 elimination pathways in pregnancy. CYP4503A4 is induced in pregnancy and is a pathway for the metabolism of E2. Conversion to estrone and Phase II metabolism via glucuronidation and sulfation, which also increase in pregnancy, are routes of E2 elimination. The time required for these pathways to normalize after delivery has not been elucidated. The observation that transdermal E2 doses greater than 100 mcg/day did not increase serum concentrations was unexpected. Another hypothesis consistent with this observation is suppression of endogenous E2 secretion with increasing exogenous E2 dosing. PMID:26061609

  20. Estradiol rapidly inhibits soluble guanylyl cyclase expression in rat uterus

    NASA Technical Reports Server (NTRS)

    Krumenacker, J. S.; Hyder, S. M.; Murad, F.

    2001-01-01

    Previous reports that investigated the regulation of the NO/soluble guanylyl cyclase (sGC)/cGMP pathway by estrogenic compounds have focused primarily on the levels of NO, NO-producing enzymes, and cGMP in various tissues. In this study, we demonstrate that 17beta-estradiol (E2) regulates the alpha(1) and beta(1) subunits of the NO receptor, sGC, at the mRNA and protein levels in rat uterus. Using real-time quantitative PCR, we found that within 1 h of in vivo E2 administration to rats, sGC mRNA levels begin to diminish. After 3 h, there is a maximal diminution of sGC mRNA expression (sGC alpha(1) 10% and sGC beta(1) 33% of untreated). This effect was blocked by the estrogen receptor antagonist, ICI 182,780, indicating that estrogen receptor is required. The effect of E2 also was observed in vitro with incubations of uterine tissue, indicating that the response does not depend on the secondary release of other hormones or factors from other tissues. Puromycin did not block the effect, suggesting the effects occur because of preexisting factors in uterine tissues and do not require new protein synthesis. Using immunoblot analysis, we found that sGC protein levels also were reduced by E2 over a similar time course as the sGC mRNA. We conclude that sGC plays a vital role in the NO/sGC/cGMP regulatory pathway during conditions of elevated estrogen levels in the rat uterus as a result of the reduction of sGC expression.

  1. Estradiol rapidly inhibits soluble guanylyl cyclase expression in rat uterus

    NASA Technical Reports Server (NTRS)

    Krumenacker, J. S.; Hyder, S. M.; Murad, F.

    2001-01-01

    Previous reports that investigated the regulation of the NO/soluble guanylyl cyclase (sGC)/cGMP pathway by estrogenic compounds have focused primarily on the levels of NO, NO-producing enzymes, and cGMP in various tissues. In this study, we demonstrate that 17beta-estradiol (E2) regulates the alpha(1) and beta(1) subunits of the NO receptor, sGC, at the mRNA and protein levels in rat uterus. Using real-time quantitative PCR, we found that within 1 h of in vivo E2 administration to rats, sGC mRNA levels begin to diminish. After 3 h, there is a maximal diminution of sGC mRNA expression (sGC alpha(1) 10% and sGC beta(1) 33% of untreated). This effect was blocked by the estrogen receptor antagonist, ICI 182,780, indicating that estrogen receptor is required. The effect of E2 also was observed in vitro with incubations of uterine tissue, indicating that the response does not depend on the secondary release of other hormones or factors from other tissues. Puromycin did not block the effect, suggesting the effects occur because of preexisting factors in uterine tissues and do not require new protein synthesis. Using immunoblot analysis, we found that sGC protein levels also were reduced by E2 over a similar time course as the sGC mRNA. We conclude that sGC plays a vital role in the NO/sGC/cGMP regulatory pathway during conditions of elevated estrogen levels in the rat uterus as a result of the reduction of sGC expression.

  2. Estradiol rapidly inhibits soluble guanylyl cyclase expression in rat uterus

    PubMed Central

    Krumenacker, Joshua S.; Hyder, Salman M.; Murad, Ferid

    2001-01-01

    Previous reports that investigated the regulation of the NO/soluble guanylyl cyclase (sGC)/cGMP pathway by estrogenic compounds have focused primarily on the levels of NO, NO-producing enzymes, and cGMP in various tissues. In this study, we demonstrate that 17β-estradiol (E2) regulates the α1 and β1 subunits of the NO receptor, sGC, at the mRNA and protein levels in rat uterus. Using real-time quantitative PCR, we found that within 1 h of in vivo E2 administration to rats, sGC mRNA levels begin to diminish. After 3 h, there is a maximal diminution of sGC mRNA expression (sGC α1 10% and sGC β1 33% of untreated). This effect was blocked by the estrogen receptor antagonist, ICI 182,780, indicating that estrogen receptor is required. The effect of E2 also was observed in vitro with incubations of uterine tissue, indicating that the response does not depend on the secondary release of other hormones or factors from other tissues. Puromycin did not block the effect, suggesting the effects occur because of preexisting factors in uterine tissues and do not require new protein synthesis. Using immunoblot analysis, we found that sGC protein levels also were reduced by E2 over a similar time course as the sGC mRNA. We conclude that sGC plays a vital role in the NO/sGC/cGMP regulatory pathway during conditions of elevated estrogen levels in the rat uterus as a result of the reduction of sGC expression. PMID:11209068

  3. Modeling the photocatalytic mineralization in water of commercial formulation of estrogens 17-β estradiol (E2) and nomegestrol acetate in contraceptive pills in a solar powered compound parabolic collector.

    PubMed

    Colina-Márquez, José; Machuca-Martínez, Fiderman; Li Puma, Gianluca

    2015-07-22

    Endocrine disruptors in water are contaminants of emerging concern due to the potential risks they pose to the environment and to the aquatic ecosystems. In this study, a solar photocatalytic treatment process in a pilot-scale compound parabolic collector (CPC) was used to remove commercial estradiol formulations (17-β estradiol and nomegestrol acetate) from water. Photolysis alone degraded up to 50% of estradiol and removed 11% of the total organic carbon (TOC). In contrast, solar photocatalysis degraded up to 57% of estrogens and the TOC removal was 31%, with 0.6 g/L of catalyst load (TiO2 Aeroxide P-25) and 213.6 ppm of TOC as initial concentration of the commercial estradiols formulation. The adsorption of estrogens over the catalyst was insignificant and was modeled by the Langmuir isotherm. The TOC removal via photocatalysis in the photoreactor was modeled considering the reactor fluid-dynamics, the radiation field, the estrogens mass balance, and a modified Langmuir-Hinshelwood rate law, that was expressed in terms of the rate of photon adsorption. The optimum removal of the estrogens and TOC was achieved at a catalyst concentration of 0.4 g/L in 29 mm diameter tubular CPC reactors which approached the optimum catalyst concentration and optical thickness determined from the modeling of the absorption of solar radiation in the CPC, by the six-flux absorption-scattering model (SFM).

  4. Mechanism of estradiol-induced block of voltage-gated K+ currents in rat medial preoptic neurons.

    PubMed

    Druzin, Michael; Malinina, Evgenya; Grimsholm, Ola; Johansson, Staffan

    2011-01-01

    The present study was conducted to characterize possible rapid effects of 17-β-estradiol on voltage-gated K(+) channels in preoptic neurons and, in particular, to identify the mechanisms by which 17-β-estradiol affects the K(+) channels. Whole-cell currents from dissociated rat preoptic neurons were studied by perforated-patch recording. 17-β-Estradiol rapidly (within seconds) and reversibly reduced the K(+) currents, showing an EC(50) value of 9.7 µM. The effect was slightly voltage dependent, but independent of external Ca(2+), and not sensitive to an estrogen-receptor blocker. Although 17-α-estradiol also significantly reduced the K(+) currents, membrane-impermeant forms of estradiol did not reduce the K(+) currents and other estrogens, testosterone and cholesterol were considerably less effective. The reduction induced by estradiol was overlapping with that of the K(V)-2-channel blocker r-stromatoxin-1. The time course of K(+) current in 17-β-estradiol, with a time-dependent inhibition and a slight dependence on external K(+), suggested an open-channel block mechanism. The properties of block were predicted from a computational model where 17-β-estradiol binds to open K(+) channels. It was concluded that 17-β-estradiol rapidly reduces voltage-gated K(+) currents in a way consistent with an open-channel block mechanism. This suggests a new mechanism for steroid action on ion channels.

  5. Estradiol-induced antinociceptive responses on formalin-induced nociception are independent of COX and HPA activation.

    PubMed

    Hunter, Deirtra A; Barr, Gordon A; Amador, Nicole; Shivers, Kai-Yvonne; Kemen, Lynne; Kreiter, Christopher M; Jenab, Shirzad; Inturrisi, Charles E; Quinones-Jenab, Vanya

    2011-07-01

    Estrogen modulates pain perception but how it does so is not fully understood. The aim of this study was to determine if estradiol reduces nociceptive responses in part via hypothalamic-pituitary-adrenal (HPA) axis regulation of cyclooxygenase (COX)-1/COX-2 activity. The first study examined the effects of estradiol (20%) or vehicle with concurrent injection nonsteroidal antiinflammatory drugs (NSAIDs) on formalin-induced nociceptive responding (flinching) in ovariectomized (OVX) rats. The drugs were ibuprofen (COX-1 and COX-2 inhibitor), SC560 (COX-1 inhibitor), or NS398 (COX-2 inhibitor). In a second study, estradiol's effects on formalin-induced nociception were tested in adrenalectomized (ADX), OVX, and ADX+OVX rats. Serum levels of prostaglandins (PG) PGE(2) and corticosterone were measured. Estradiol significantly decreased nociceptive responses in OVX rats with effects during both the first and the second phase of the formalin test. The nonsteroidal antiinflammatory drugs (NSAIDs) did not alter nociception at the doses used here. Adrenalectomy neither altered flinching responses in female rats nor reversed estradiol-induced antinociceptive responses. Estradiol alone had no effect on corticosterone (CORT) or prostaglandin levels after the formalin test, dissociating the effects of estradiol on behavior and these serum markers. Ibuprofen and NS398 significantly reduced PGE2 levels. CORT was not decreased by OVX surgery or by estradiol below that of ADX. Only IBU significantly increased corticosterone levels. Taken together, our results suggest that estradiol-induced antinociception in female rats is independent of COX activity and HPA axis activation.

  6. Mechanism of Estradiol-Induced Block of Voltage-Gated K+ Currents in Rat Medial Preoptic Neurons

    PubMed Central

    Druzin, Michael; Malinina, Evgenya; Grimsholm, Ola; Johansson, Staffan

    2011-01-01

    The present study was conducted to characterize possible rapid effects of 17-β-estradiol on voltage-gated K+ channels in preoptic neurons and, in particular, to identify the mechanisms by which 17-β-estradiol affects the K+ channels. Whole-cell currents from dissociated rat preoptic neurons were studied by perforated-patch recording. 17-β-estradiol rapidly (within seconds) and reversibly reduced the K+ currents, showing an EC50 value of 9.7 µM. The effect was slightly voltage dependent, but independent of external Ca2+, and not sensitive to an estrogen-receptor blocker. Although 17-α-estradiol also significantly reduced the K+ currents, membrane-impermeant forms of estradiol did not reduce the K+ currents and other estrogens, testosterone and cholesterol were considerably less effective. The reduction induced by estradiol was overlapping with that of the KV-2-channel blocker r-stromatoxin-1. The time course of K+ current in 17-β-estradiol, with a time-dependent inhibition and a slight dependence on external K+, suggested an open-channel block mechanism. The properties of block were predicted from a computational model where 17-β-estradiol binds to open K+ channels. It was concluded that 17-β-estradiol rapidly reduces voltage-gated K+ currents in a way consistent with an open-channel block mechanism. This suggests a new mechanism for steroid action on ion channels. PMID:21625454

  7. Accounting for human variability and sensitivity in setting standards for electromagnetic fields.

    PubMed

    Bailey, William H; Erdreich, Linda S

    2007-06-01

    Biological sensitivity and variability are key issues for risk assessment and standard setting. Variability encompasses general inter-individual variations in population responses, while sensitivity relates to unusual or extreme responses based on genetic, congenital, medical, or environmental conditions. For risk assessment and standard setting, these factors affect estimates of thresholds for effects and dose-response relationships and inform efforts to protect the more sensitive members of the population, not just the typical or average person. While issues of variability and sensitivity can be addressed by experimental and clinical studies of electromagnetic fields, investigators have paid little attention to these important issues. This paper provides examples that illustrate how default assumptions regarding variability can be incorporated into estimates of 60-Hz magnetic field exposures with no risk of cardiac stimulation and how population thresholds and variability of peripheral nerve stimulation responses at 60-Hz can be estimated from studies of pulsed gradient magnetic fields in magnetic resonance imaging studies. In the setting of standards for radiofrequency exposures, the International Commission for Non-Ionizing Radiation Protection uses inter-individual differences in thermal sensitivity as one of the considerations in the development of "safety factors." However, neither the range of sensitivity nor the sufficiency or excess of the 10-fold and the additional 5-fold safety factors have been assessed quantitatively. Data on the range of responses between median and sensitive individuals regarding heat stress and cognitive function should be evaluated to inform a reassessment of these safety factors and to identify data gaps.

  8. Estradiol receptor of calf uterus: interactions with heparin-agarose and purification.

    PubMed Central

    Molinari, A M; Medici, N; Moncharmont, B; Puca, G A

    1977-01-01

    Heparin attached covalently to agarose beads binds the "native" form of the estradiol receptor with very high affinity. Chondroitin sulfate does not bind to the receptor. When the receptor is complexed with hormone, the affinity is at least 10 times higher. Only the "native" and not the "nuclear" or the "derived" (i.e., after activation by a calcium-dependent enzyme) forms of the estradiol receptor interact with heparin. The "native" estradiol-receptor complex is purified to homogeneity after chromatography on columns of heparin-agarose, Sephadex G-200, and DEAE-cellulose, followed by two more Sephadex G-200 columns. The purified molecule is a single polypeptide of molecular weight 69,000 by polyacrylamide gel electrophoresis in sodium dodecyl sulphate. The sedimentation coefficient on sucrose gradients is 4.3 S, the Stokes radius from gel filtration is 36.5 A, and the isoelectric point is 6.4. The purified [3H]estradiol-receptor complex exchanges the radioactive hormone with