722 resultados para Female hormones


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This study was designed to evaluate the effects of certain orally active contraceptive steroids on the eye, related to the tolerance of a corneal contact lens. An oestrogen, ethinyloestradiol BP. 0.05 mg, a progestogen, norethisterone acetate BP. 2.50 mg and a control tablet (vitamin C, 50 mg) were utilised. The effect of these preparations on corneal curvature, lacrimal fluid volume and protein composition and directly on corneal lens tolerance was monitored in a group of 23 volunteer patients. The progestogen was found to produce a significant (P≥ 0.05) decrease in tear volume as measured by a 3 minute Schirmer test. A smaller volume reduction was observed with ethinyloestradiol. A normal cornea appears unaffected, within the measurement limits available, by the use of either hormone. However, in the presence of a corneal lens, oestrogen was found to induce substantial corneal steepening, indicative of tissue oedema, during the initial 2-3 weeks of medication. Progestogen occasionally produced a similar effect, which could recur with either hormone shortly after the end of the treatment period. A new method of acrylamide gel electrophoresis was developed for examination of the protein concentration and composition of lacrimal fluid. This allowed much greater resolution of microquantities of unconcentrated fluid than anything previously reported. Quantitation by densitometry has permitted the recording of medication and lens-induced changes in the protein pattern. Tear albumin has been shown to differ from serum albumin and to consist of up to 3 subfractions, 7 further protein fractions may also be resolved. The concentration and probable origin of these proteins have been established and the overall effects of hormone administration described. Individual idiosyncratic responses are also discussed. The study has established tbenature of some effects of contraceptive steroids on the anterior eye, and the probable reasons for resultant corneal lens intolerance.

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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.

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The diuretic and natriuretic responses to exogenous synthetic atrial natriuretic peptide (ANP) were evaluated in patients with chronic renal failure (CRF) or nephrotic syndrome (NS). Patients were studied after an oral water load (8 ml/kg in CRF and 20 ml/kg in NS patients). A short intravenous bolus of either a placebo or ANP was administered when urine output was stable. In each group of patients, three doses of ANP were injected at 24 h intervals, i.e., 1.0, 1.5, and 2.0 micrograms/kg in the CRF and 1.0, 1.5, and 3.0 micrograms/kg in the NS group. Blood pressure and heart rate were monitored throughout the study and urinary volume and electrolyte excretion were measured every 20 min up to 3 h after the bolus. An acute and transient fall in blood pressure was observed immediately after the ANP injection. It was more pronounced in CRF than in NS patients. In CRF patients, ANP caused only a slight increase in urinary volume (13.5-44% over baseline) but a significant increase in urinary sodium excretion (45-114% over baseline). In NS patients, significant increases in both urine volume (60-105%) and sodium excretion (149-248%) were also found. In these latter patients, the renal response to ANP appeared to be better preserved. The hemodynamic and renal changes induced by ANP occurred mainly during the first 20 min following the ANP administration, when the peak plasma ANP levels were obtained. However, no clear dose-response effect could be evidenced in either group with the three doses of ANP chosen in this study.

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This study evaluated the spirometry and respiratory static pressures in 17 young women, twice a week for three successive ovulatory menstrual cycles to determine if such variables changed across the menstrual, follicular, periovulatory, early-tomid luteal and late luteal phases. The factors phases of menstrual cycle and individual cycles had no significant effect on the spirometry variables except for peak expiratory flow (PEF) and respiratory static pressures. Significant weak positive correlations were found between the progesterone:estradiol ratio and PEF and between estrogen and tidal volume (r = 0.37), inspiratory time (r = 0.22), expiratory time (r = 0.19), maximal inspiratory pressure (r = 0.25) and maximal expiratory pressure (r = 0.20) and for progesterone and maximal inspiratory pressure (r = 0.32) during the early-to-mid luteal phase. Although most parameters of the spirometry results did not change during the menstrual cycle, the correlations observed between sexual hormones and respiratory control variables suggest a positive influence of sexual female hormones controlling the thoracic pump muscles in the luteal phase

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Introduction the selective serotonin reuptake inhibitors have become the most frequently prescribed drugs for the treatment of depression. Sexual side effects have been noted to occur with this treatment on heterosexual behavior in rats. Heterosexual experience facilitates sexual orientation of male rats and decreases the latencies to first mount and first intromission. on the other hand, homosexual behavior in male rats induced by female hormones has not been evaluated.Aim the objective of this work is to evaluate the effects of heterosexual and homosexual experience in male rats long-term treated with fluoxetine (FLX) on homosexual hormone-induced behavior.Materials and Methods Male rats were treated with FLX or saline solution (10 mg/kg for 65 days). At days 36, 50, and 65 of the treatment, the rats were evaluated for homosexual behavior. Other rats treated with FLX or saline solution for 60 consecutive days were submitted to heterosexual behavior at 14, 21, and 28 days of the treatment. After this, they were orquiectomized and homosexual hormone-induced behavior was observed at 45 and 60 days of the treatment.Results (1) Only treatment with FLX did not affect the homosexual behavior. (2) the homosexual experience facilitated the homosexual behavior mainly on the animals from the control group. (3) the heterosexual experience facilitated the homosexual behavior on both groups.Conclusions Only long-term administration of FLX does not interfere with the homosexual behavior in male rats. The homosexual and the heterosexual experience facilitated the homosexual behavior on the control and experimental groups. We suggested that learning aspects related to sexual behavior are responsible by these results.

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The objective was to analyze and report field data focusing on the effect of type of progesterone-releasing vaginal insert and dose of pLH on embryo production, following a superstimulatory protocol involving fixed-time artificial insemination (FTAI) in Nelore cattle (Bos taurus indicus). Donor heifers and cows (n = 68; 136 superstimulations over 2 years) received an intravaginal, progesterone-releasing insert (CIDR® or DIB®, with 1.9 or 1.0 g progesterone, respectively) and 3-4 mg of estradiol benzoate (EB) i.m. at random stages of the estrous cycle. Five days later (designated Day 0), cattle were superstimulated with a total of 120-200 mg of pFSH (Folltropin-V®), given twice daily in decreasing doses from Days 0 to 3. All cattle received two luteolytic doses of PGF2α at 08:00 and 20:00 h on Day 2 and progesterone inserts were removed at 20:00 h on Day 3 (36 h after the first PGF2α injection). Ovulation was induced with pLH (Lutropin-V®, 12.5 or 25 mg, i.m.) at 08:00 h on Day 4 with FTAI 12, 24 and in several cases, 36 h later. Embryos were recovered on Days 11 or 12, graded and transferred to synchronous recipients. Overall, the mean (±S.E.M.) number of total ova/embryos (13.3 ± 0.8) and viable embryos (9.4 ± 0.6) and pregnancy rate (43.5%; 528/1213) did not differ among groups, but embryo viability rate (overall, 70.8%) was higher in donors with a DIB (72.3%) than a CIDR (68.3%, P = 0.007). In conclusion, the administration of pLH 12 h after progesterone removal in a progestin-based superstimulatory protocol facilitated fixed-time AI in Nelore donors, with embryo production, embryo viability and pregnancy rates after embryo transfer, comparable to published results where estrus detection and AI was done. Results suggested a possible alternative, which would eliminate the need for estrus detection in donors. © 2006 Elsevier Inc. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Ciências da Motricidade - IBRC

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Background. Primary liver cancer, the majority of which is hepatocellular carcinoma, is the third most common cause of mortality from cancer. It has one of the worst prognosis outcomes and an overall 5-year survival of only 5-6%. Hepatocellular carcinoma has been shown to have wide variations in geographic distribution and there is a marked difference in the incidence between different races and gender. Previously low-rate countries, including the US, have shown to have doubled the incidence of HCC during the past two decades. Even though the incidence of HCC is higher in males as compared to females, female hormones, especially estrogens have been postulated to have a role in the development of hepatocellular carcinoma on a molecular level. Despite the frequent usage of oral contraceptive pills (OCP) and previously, hormone replacement therapy (HRT), their role on HCC development has not been studied thoroughly. We aim to examine the association between exogenous hormone intake (oral contraceptives and post-menopausal hormone replacement therapy) and the development of HCC. Methods. This study is part of an ongoing hospital-based case-control study which is conducted at the Department of Gastrointestinal Oncology at The University of Texas M. D. Anderson Cancer Center. From January 2005 up to January 2008, a total of 77 women with pathologically confirmed hepatocellular carcinoma (cases) and 277 healthy women (controls) were included in the investigation. Information about the use of hormonal contraceptives, hormone replacement therapy and risk factors of hepatocellular cancer was collected by personal interview. Univariate and multivariate logistic regression analyses were done to estimate the crude odds ratios (OR) and adjusted odds ratios (AOR). Results. We found statistically significant protective effect for the use of HRT on the development of HCC, AOR=0.42 (95% CI, 0.21, 0.81). The significance was observed for estrogen replacement, AOR=0.43 (95% CI, 0.22, 0.83) and not for progesterone replacement, AOR=0.49 (95% CI, 0.10, 2.35). On the other hand, any hormonal contraceptive use, which encompasses oral contraceptive pills, implants and injections, did not show a statistical significance either in the crude OR=0.58 (95% CI, 0.33, 1.01) or AOR=0.56 (95% CI 0.26, 1.18). Conclusions. As corroborated by previous studies, HRT confers 58% HCC risk reduction among American women. The more important question of the association between hormonal contraceptives and HCC remains controversial. Further studies are warranted to explore the mechanism of the protective effect of HRT and the relationship between hormonal contraception and HCC.^

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This study evaluated the spirometry and respiratory static pressures in 17 young women, twice a week for three successive ovulatory menstrual cycles to determine if such variables changed across the menstrual, follicular, periovulatory, early-tomid luteal and late luteal phases. The factors phases of menstrual cycle and individual cycles had no significant effect on the spirometry variables except for peak expiratory flow (PEF) and respiratory static pressures. Significant weak positive correlations were found between the progesterone:estradiol ratio and PEF and between estrogen and tidal volume (r = 0.37), inspiratory time (r = 0.22), expiratory time (r = 0.19), maximal inspiratory pressure (r = 0.25) and maximal expiratory pressure (r = 0.20) and for progesterone and maximal inspiratory pressure (r = 0.32) during the early-to-mid luteal phase. Although most parameters of the spirometry results did not change during the menstrual cycle, the correlations observed between sexual hormones and respiratory control variables suggest a positive influence of sexual female hormones controlling the thoracic pump muscles in the luteal phase

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This study evaluated the spirometry and respiratory static pressures in 17 young women, twice a week for three successive ovulatory menstrual cycles to determine if such variables changed across the menstrual, follicular, periovulatory, early-tomid luteal and late luteal phases. The factors phases of menstrual cycle and individual cycles had no significant effect on the spirometry variables except for peak expiratory flow (PEF) and respiratory static pressures. Significant weak positive correlations were found between the progesterone:estradiol ratio and PEF and between estrogen and tidal volume (r = 0.37), inspiratory time (r = 0.22), expiratory time (r = 0.19), maximal inspiratory pressure (r = 0.25) and maximal expiratory pressure (r = 0.20) and for progesterone and maximal inspiratory pressure (r = 0.32) during the early-to-mid luteal phase. Although most parameters of the spirometry results did not change during the menstrual cycle, the correlations observed between sexual hormones and respiratory control variables suggest a positive influence of sexual female hormones controlling the thoracic pump muscles in the luteal phase

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We have previously demonstrated that blockade of β-adrenoreceptors (β-AR) located in the temporomandibular joint (TMJ) of rats suppresses formalin-induced TMJ nociceptive behaviour in both male and female rats, but female rats are more responsive. In this study, we investigated whether gonadal hormones modulate the responsiveness to local β-blocker-induced antinociception in the TMJ of rats. Co-administration of each of the selective β1 (atenolol), β2 (ICI 118.551) and β3 (SR59230A)-AR antagonists with equi-nociceptive concentrations of formalin in the TMJ of intact, gonadectomized and hormone-treated gonadectomized male and female rats. Atenolol, ICI 118.551 and SR59230A significantly reduced formalin-induced TMJ nociception in a dose response fashion in all groups tested. However, a lower dose of each β-AR antagonist was sufficient to significantly reduce nociceptive responses in gonadectomized but not in intact and testosterone-treated gonadectomized male rats. In the female groups, a lower dose of β1 -AR antagonist was sufficient to significantly reduce nociceptive responses in gonadectomized but not in intact or gonadectomized rats treated with progesterone or a high dose of oestradiol; a lower dose of β2 -AR antagonist was sufficient to significantly reduce nociceptive responses in gonadectomized but not in intact and gonadectomized rats treated with low or high dose of oestradiol. Gonadal hormones may reduce the responsiveness to local β-blocker-induced antinociception in the TMJ of male and female rats. However, their effect depends upon their plasma level, the subtype of β-AR and the dose of β-blockers used.

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Background: Fluctuations of estradiol and progesterone levels caused by the menstrual cycle worsen asthma symptoms. Conflicting data are reported in literature regarding pro and anti-inflammatory properties of estradiol and progesterone. Methods: Female Wistar rats were ovalbumin (OVA) sensitized 1 day after resection of the ovaries (OVx). Control group consisted of sensitized-rats with intact ovaries (Sham-OVx). Allergic challenge was performed by aerosol (OVA 1%, 15 min) two weeks later. Twenty four hours after challenge, BAL, bone marrow and total blood cells were counted. Lung tissues were used as explants, for expontaneous cytokine secretion in vitro or for immunostaining of E-selectin. Results: We observed an exacerbated cell recruitment into the lungs of OVx rats, reduced blood leukocytes counting and increased the number of bone marrow cells. Estradiol-treated OVx allergic rats reduced, and those treated with progesterone increased, respectively, the number of cells in the BAL and bone marrow. Lungs of OVx allergic rats significantly increased the E-selectin expression, an effect prevented by estradiol but not by progesterone treatment. Systemically, estradiol treatment increased the number of peripheral blood leukocytes in OVx allergic rats when compared to non treated-OVx allergic rats. Cultured-BAL cells of OVx allergic rats released elevated amounts of LTB(4) and nitrites while bone marrow cells increased the release of TNF-alpha and nitrites. Estradiol treatment of OVx allergic rats was associated with a decreased release of TNF-alpha, IL-10, LTB4 and nitrites by bone marrow cells incubates. In contrast, estradiol caused an increase in IL-10 and NO release by cultured-BAL cells. Progesterone significantly increased TNF-alpha by cultured BAL cells and bone marrow cells. Conclusions: Data presented here suggest that upon hormonal oscillations the immune sensitization might trigger an allergic lung inflammation whose phenotype is under control of estradiol. Our data could contribute to the understanding of the protective role of estradiol in some cases of asthma symptoms in fertile ans post-menopausal women clinically observed.

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Female sex hormones (FSHs) exert profound regulatory effects on the course of lung inflammation due to allergic and non-allergic immune responses. As pollution is one of the pivotal factors to induce lung dysfunction, in this study we investigated the modulatory role of FSHs on lung inflammation after a formaldehyde (FA) exposure. For this purpose, lung and systemic inflammatory responses were evaluated in terms of leukocytes countings in bronchoalveolar lavage (BAL), peripheral blood and bone marrow lavage from 7-day ovariectomized (OVx) and Sham-OVx rats subjected to FA inhalation for 3 consecutive days. The hypothesized link between effects of FSHs on expression of adhesion molecules and mast cells degranulation was also studied. Once exposed to FA, Sham-OVx rats increased the number of total cells recovered in BAL and of leukocytes in peripheral blood, and decreased the counts in bone marrow. By contrast, in OVx rats upon FA exposure there was a reduction of the total cells counts in BAL and of blood leukocytes: lung expressions of ICAM-1 and Mac-1 were depressed, but the number of bone marrow cells did not vary. Estradiol treatment of OVx rats increased the total cells in BAL and decreased the number of blood leukocytes, whereas the number of bone marrow cell remained unaltered. Progesterone treatment, in turn increased the total cells in BAL and blood leukocytes, but decreased the number of bone marrow cells. OVx rats exposed to FA developed tracheal hyperresponsiveness to methacholine (MCh). A similarly altered response was found between the tracheal segments of Sham-OVx rats after FA exposure and that found in tracheae of naive rats. Estradiol treatment prevented FA-induced tracheal hyperresponsiveness to MCh whereas progesterone was ineffective in this regard. In addition, OVx rats upon FA exposure significantly increased both, the ability of mast cell degranulation and serum corticosterone levels. In conclusion, it was found that FSHs act by distinct control mechanisms on FA-induced lung inflammation and tracheal hyperresponsiveness, since at low circulating levels of FSHs (such as those after OVx) there is some resistance to the development of a lung inflammatory response, but the cholinergic tracheal responsiveness is exacerbated. Our data also help to understand the involvement of FSHs on mast cells activity after pollutants exposure and add information regarding the role of FSHs on the mechanisms related to endothelium-leukocyte interactions. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

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The etiology of hormone-induced cancers has been considered to be a combination of genotoxic and epigenetic events. Currently, the Comet assay is widely used for detecting genotoxicity because it is relatively simple, sensitive, and capable of detecting various kinds of DNA damage. The present study evaluates the genotoxic potential of endogenous and synthetic sex hormones, as detected by the Comet assay. Blood cells were obtained from 12 nonsmoking and 12 smoking women with regular menstrual cycles and from 12 nonsmoking women taking low-dose oral contraceptives (OC). Peripheral blood samples were collected at three phases of the menstrual cycle (early follicular, mean follicular, and luteal phases), or at three different moments of oral contraceptive intake. Three blood samples were also collected from 12 healthy nonsmoking men, at the same time as oral contraceptive users. Results showed no significant difference in the level of DNA damage among the three moments of the menstrual cycle either in nonsmoking and smoking women, or between them. No significant difference in DNA damage was also observed among oral contraceptive users, nonusers, and men. Together, these data indicate lack of genotoxicity induced by the physiological level of the female sex hormones and OC as assessed by the alkaline Comet assay. In conclusion, normal fluctuation in endogenous sex hormones and use of low-doses of oral contraceptive should not interfere with Comet assay data when this technique is used for human biomonitoring.