55 resultados para progesterone
Vascular endothelial growth factor-A and aldosterone: relevance to normal pregnancy and preeclampsia
Resumo:
Aldosterone levels are markedly elevated during normal pregnancy but fall even though volume contracts when preeclampsia occurs. The level of aldosterone in either condition cannot be explained solely by the activity of the renin-angiotensin II system. In normal gestation, vascular endothelial growth factor (VEGF) is thought to maintain vascular health, but its role in adrenal hormone production is unknown. We hypothesized that the role of VEGF in the adrenal gland is to maintain vascular health and regulate aldosterone production. Here, we demonstrate that supernatant of endothelial cells grown in the presence of VEGF enhanced aldosterone synthase activity in human adrenocortical cells. VEGF either alone or combined with angiotensin II increased aldosterone production in adrenal cells. These data suggest that endothelial cell-dependent and independent activation of aldosterone is regulated by VEGF. In contrast to angiotensin II, VEGF did not upregulate the steroidogenic acute regulatory protein. Consistent with this observation, angiotensin II stimulated both aldosterone and cortisol synthesis from progesterone, whereas VEGF stimulated selectively aldosterone production. In rats, overexpression of soluble fms-like tyrosine kinase-1, an endogenous VEGF inhibitor, led to adrenocortical capillary rarefaction and fall in aldosterone concentrations that correlated inversely with soluble fms-like tyrosine kinase-1 levels. These findings may explain why aldosterone increases so markedly during normal gestation and why preeclampsia, a condition characterized by high soluble fms-like tyrosine kinase-1, is associated with inappropriately low aldosterone levels in spite of relatively lower plasma volumes.
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BACKGROUND: Delayed uterine involution has negative effects on the fertility of cows; use of prostaglandin F2alpha alone as a single treatment has not been shown to consistently improve fertility. Combined administration of PGF2alpha and PGE2 increased uterine pressure in healthy cows. We hypothesized, that the combination of both prostaglandins would accelerate uterine involution and have, therefore, a positive effect on fertility variables. In commercial dairy farming, the benefit of a single post partum combined prostaglandin treatment should be demonstrated. METHODS: 383 cows from commercial dairy farms were included in this study. Uterine size and secretion were evaluated at treatment 21-35 days post partum and 14 days later. Cows were randomly allocated to one of three treatment groups: PGF2alpha and PGE2, PGF2alpha or placebo. For every animal participating in the study, the following reproduction variables were recorded: Interval from calving to first insemination, days open, number of artificial inseminations (AI) to conception; subsequent treatment of uterus, subsequent treatment of ovaries. Plasma progesterone level at time of treatment was used as a covariable. For continuous measurements, analysis of variance was performed. Fisher's exact test for categorical non-ordered data and exact Kruskal-Wallis test for ordered data were used; pairwise group comparisons with Bonferroni adjustment of significance level were performed. RESULTS: There was no significant difference among treatment groups in uterine size. Furthermore, there was no significant difference among treatments concerning days open, number of AI, and subsequent treatment of uterus and ovaries. Days from calving to first insemination tended to be shorter for cows with low progesterone level given PGF2alpha and PGE2 in combination than for the placebo-group (P = 0.024). CONCLUSION: The results of this study indicate that the administration of PGF2alpha or a combination of PGF2alpha and PGE2 21 to 35 days post partum had no beneficial effect upon measured fertility variables. The exception was a tendency for a shorter interval from calving to first insemination after administration of the combination of PGF2alpha and PGE2, as compared to the placebo group. Further research should be done in herds with reduced fertility and/or an increased incidence of postpartum vaginal discharge.
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BACKGROUND: Tumor levels of steroid hormone receptors, a factor used to select adjuvant treatment for early-stage breast cancer, are currently determined with immunohistochemical assays. These assays have a discordance of 10%-30% with previously used extraction assays. We assessed the concordance and predictive value of hormone receptor status as determined by immunohistochemical and extraction assays on specimens from International Breast Cancer Study Group Trials VIII and IX. These trials predominantly used extraction assays and compared adjuvant chemoendocrine therapy with endocrine therapy alone among pre- and postmenopausal patients with lymph node-negative breast cancer. Trial conclusions were that combination therapy provided a benefit to pre- and postmenopausal patients with estrogen receptor (ER)-negative tumors but not to ER-positive postmenopausal patients. ER-positive premenopausal patients required further study. METHODS: Tumor specimens from 571 premenopausal and 976 postmenopausal patients on which extraction assays had determined ER and progesterone receptor (PgR) levels before randomization from October 1, 1988, through October 1, 1999, were re-evaluated with an immunohistochemical assay in a central pathology laboratory. The endpoint was disease-free survival. Hazard ratios of recurrence or death for treatment comparisons were estimated with Cox proportional hazards regression models, and discriminatory ability was evaluated with the c index. All statistical tests were two-sided. RESULTS: Concordance of hormone receptor status determined by both assays ranged from 74% (kappa = 0.48) for PgR among postmenopausal patients to 88% (kappa = 0.66) for ER in postmenopausal patients. Hazard ratio estimates were similar for the association between disease-free survival and ER status (among all patients) or PgR status (among postmenopausal patients) as determined by the two methods. However, among premenopausal patients treated with endocrine therapy alone, the discriminatory ability of PgR status as determined by immunohistochemical assay was statistically significantly better (c index = 0.60 versus 0.51; P = .003) than that determined by extraction assay, and so immunohistochemically determined PgR status could predict disease-free survival. CONCLUSIONS: Trial conclusions in which ER status (for all patients) or PgR status (for postmenopausal patients) was determined by immunohistochemical assay supported those determined by extraction assays. However, among premenopausal patients, trial conclusions drawn from PgR status differed--immunohistochemically determined PgR status could predict response to endocrine therapy, unlike that determined by the extraction assay.
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OBJECTIVE: Only a few studies have investigated variations of different markers for inflammatory processes during the physiological menstrual cycle. The results are conflicting, particularly concerning the correlation between the marker leptin and steroid hormones. The aim of the study was to investigate the inflammatory markers C-reactive protein (CRP) and leptin in the serum of healthy, normally ovulating women and to correlate these with each other and with the hormones of the gonadal axis. A cycle-dependence of the markers studied would imply an exact timing of the blood sampling for clinical needs. DESIGN: Observational study investigating the two inflammatory markers CRP and leptin in relation to the hormonal pattern of the gonadal axis during the normal cycle. METHODS: Ovulatory cycles of 36 healthy, young, normo-androgenic women, having a normal body mass index were evaluated. Serum concentrations of leptin and CRP, as well as of follicle-stimulating hormone, luteinising hormone, 17beta-oestradiol, progesterone, prolactin (PRL) and free testosterone were measured every 1-2 days during one full cycle. RESULTS: Serum levels of leptin and CRP behaved differently during ovulatory cycles, with higher concentrations for leptin only during certain phases. Significant correlations were found in the follicular phase between leptin and PRL and leptin and free testosterone. CONCLUSIONS: Leptin levels change during the menstrual cycle. Leptin levels are more stable on cycle days 1-5 than later in the cycle. For precise cycle-independent measurements, these fluctuations have to be taken into account. There is no similar cyclic pattern for CRP.
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OBJECTIVE: Postmenopausal bone loss and osteoporotic fractures can be prevented by hormone replacement therapy (HRT). However, opposed HRT may increase the risk of breast cancer above that associated with estrogen alone and in non-hysterectomized women estrogen substitution alone increases the risk of uterine cancer, which triggered renewed interest in long-cycle HRT regimens (estrogen replacement therapy with progesterone-free intervals up to 6 months). The effects on bone of such long-cycle HRT regimens are unknown. The objective of the present study was to compare the effects on bone and the endometrium of long-cycle HRT and conventional HRT. METHODS: Seventy-three healthy non-hysterectomized postmenopausal women were randomized to either conventional HRT (estradiol (E2) 2 mg/d during 12 days, E2 2 mg/d plus 1 mg/d of norethisterone acetate (NETA) during 10 days, E2 1 mg/d for 6 days) or long-cycle HRT treatment (two cycles with E2 2 mg/d during 28 days, followed by one cycle of conventional HRT and repeated every 3 months). Primary endpoint was the change in bone mineral density (BMD) at the lumbar spine (LS) over 24 months. RESULTS: BMD at LS increased significantly versus baseline in both treatment groups (conventional HRT +3.8 +/- 0.6%, long-cycle HRT +3.3 +/- 0.5%, p < 0.0001 for both) with no significant difference between treatment groups over 24 months. Similar significant BMD increases versus baseline were observed at the femoral neck, while biochemical markers of bone turnover (osteocalcin and deoxypyridinoline) were significantly decreased over 24 months. There were no endometrial or breast related adverse events reported. CONCLUSION: Long-cycle HRT may be a valid alternative to conventional HRT with regard to protection against postmenopausal bone loss.
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OBJECTIVE: The purpose of this study was to evaluate whether pregnancy-associated plasma protein A, glycodelin, osteoprotegerin, and soluble CD163 are possible peritoneal fluid markers for endometriosis and to compare them with the established chemokine markers interleukin-8 and regulated on activation, normal T-cell expressed and secreted. STUDY DESIGN: Determination of the concentrations of interleukin-8, regulated on activation, normal T-cell expressed and secreted, pregnancy-associated plasma protein A, glycodelin, CD163, osteoprotegerin, and progesterone in the peritoneal fluid collected from women undergoing laparoscopy. RESULTS: From a total of 132 women, 77 women were diagnosed with endometriosis, and 55 women were free of the disease and served as control subjects. Pregnancy-associated plasma protein A and osteoprotegerin showed significantly (P < 0.05) elevated peritoneal fluid concentrations as a function of the severity of the disease, together with interleukin-8 and regulated on activation, normal T-cell expressed and secreted (P < .001). Glycodelin and CD163 did not differ between cases and control subjects. Many of these marker concentrations were intercorrelated strongly. CONCLUSION: Pregnancy-associated plasma protein A and osteoprotegerin may play a role in the inflammation process of endometriosis, but interleukin-8 and regulated on activation, normal T-cell expressed and secreted are superior peritoneal fluid markers.
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Primary renal tumors are rare neoplasms in nonhuman primates. This report describes a mixed epithelial and stromal tumor of the kidney (MESTK) in a 14.5-year-old female ringtail lemur. The well-demarcated, solid, and cystic mass was located in the pelvis of the left kidney and consisted histologically of both epithelial and mesenchymal components. The mesenchymal cells were arranged in fascicles around cysts lined by a well-differentiated epithelium. Neither the mesenchymal nor the epithelial parts showed significant nuclear atypia or mitotic figures. To our knowledge, only 1 similar case, classified as adenoleiomyofibromatous hamartoma, has been reported in a ringtail lemur. In humans this tumor affects predominantly perimenopausal women and can express estrogen and progesterone receptors. However, neither estrogen nor progesterone receptors could be identified by immunohistochemistry in the tumor of the present ringtail lemur. Therefore, a hormonal mechanism could not be demonstrated in this case.
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Pollakisuria in adult goats can be caused by diseases of the urinary tract and by distension of parts of the genital tract leading to irritation of the bladder. Hydrometra is the most common cause of uterine distension in goats and usually can be resolved by prostaglandin injections. But other pathologies of the uterus can generate a similar syndrome. A dwarf goat was presented at the clinic with a history of chronic pollakisuria and tenesm. An initial ultrasonographic examination of the abdomen led to the suspicion of hydrometra, but treatment with injections of prostaglandin were not successful. Blood samples revealed low progesterone and high oestrogen values. A laparotomy was performed and an enlarged uterus with 1.5 L of mucous content and cystic ovaries were found and partially removed. A single solid leiomyoma was diagnosed histologically in the uterine wall. Two months later the goat's condition had deteriorated and therefore she was euthanized. Necropsy and pathohistological examination revealed the presence of a metastasized adenocarcinoma of the uterus. In this case, the pollakisuria provoqued by distension of the uterus was not caused by hydrometra, but by neoplasia. The syndrome and the pathogenesis of the adenocarcinoma in consideration of the hormonal status of the patient is discussed.
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Preeclampsia is a hypertensive disorder unique to pregnancy and remains the leading cause of maternal and fetal morbidity and mortality. Despite active research, the etiology of this disease remains still an enigma. There is increasing evidence that a combination of several factors is responsible for the development of preeclampsia. In this review, we discuss the role of aldosterone in the regulation of body fluid in pregnancy and preeclampsia. Aldosterone is produced by the enzyme aldosterone synthase and competes with cortisol and progesterone for the mineralocorticoid receptor, thus affecting sodium reabsorption and maternal volume expansion. Aldosterone seems to play a pivotal role in controlling blood pressure during pregnancy and to contribute to the well-being of the mother-to-be. Novel findings in understanding the underlying causes of preeclampsia provide a rationale for future novel prophylactic and therapeutic interventions in the treatment of this pregnancy-associated disease.
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In this phase III, multinational, randomized trial, the International Breast Cancer Study Group, Breast International Group, and the National Surgical Adjuvant Breast and Bowel Project will attempt to define the effectiveness of cytotoxic therapy for patients with locoregional recurrence of breast cancer. We will evaluate whether chemotherapy prolongs disease-free survival and, secondarily, whether its use improves overall survival and systemic disease-free survival. Quality of life measurements will be monitored during the first 12 months of the study. Women who have had a previous diagnosis of invasive breast cancer treated by mastectomy or breast-conserving surgery and who have undergone complete surgical excision of all macroscopic disease but who subsequently develop isolated local and/or regional ipsilateral invasive recurrence are eligible. Patients are randomized to observation/no adjuvant chemotherapy or to adjuvant chemotherapy; all suitable patients receive radiation, hormonal, and trastuzumab therapy. Radiation therapy is recommended for patients who have not received previous adjuvant radiation therapy but is required for those with microscopically positive margins. The radiation field must encompass the tumor bed plus a surrounding margin to a dose of >or= 40 Gy. Radiation therapy will be administered before, during, or after chemotherapy. All women with estrogen receptor-positive and/or progesterone receptor-positive recurrence must receive hormonal therapy, with the agent and duration to be determined by the patient's investigator. Adjuvant trastuzumab therapy is permitted for those with HER2- positive tumors, provided that intent to treat is declared before randomization. Although multidrug regimens are preferred, the agents, doses, and use of supportive therapy are at the discretion of the investigator.
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TRPV6 is an endothelial calcium entry channel that is strongly expressed in breast adenocarcinoma tissue. In this study, we further confirmed this observation by analysis of breast cancer tissues, which indicated that TRPV6 mRNA expression was up-regulated between 2-fold and 15-fold compared with the average in normal breast tissue. Whereas TRPV6 is expressed in the cancer tissue, its role as a calcium channel in breast carcinogenesis is poorly understood. Therefore, we investigated how TRPV6 affects the viability, apoptosis, and calcium transport in the breast cancer cell line T47D. Hormones can also affect the tumor development; hence, we determined the effects of estradiol, progesterone, and 1,25-vitamin D on TRPV6 transcription. Interestingly, the estrogen receptor antagonist tamoxifen reduced expression of TRPV6 and is able to inhibit its calcium transport activity (IC(50), 7.5 micromol/L). The in vitro model showed that TRPV6 can be regulated by estrogen, progesterone, tamoxifen, and 1,25-vitamin D and has a large influence on breast cancer cell proliferation. Moreover, the effect of tamoxifen on cell viability was enhanced when TRPV6 expression was silenced with small interfering RNA. TRPV6 may be a novel target for the development of calcium channel inhibitors to treat breast adenocarcinoma expressing TRPV6.
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Estradiol and progesterone are crucial for the acquisition of receptivity and the change in transcriptional activity of target genes in the implantation window. The aim of this study was to differentiate the regulation of genes in the endometrium of patients with recurrent implantation failure (IF) versus those who became pregnant after in vitro fertilization (IVF) treatment. Moreover, the effect of embryo-derived factors on endometrial transcriptional activity was studied. Nine women with known IVF outcome (IF, M, miscarriage, OP, ongoing pregnancy) and undergoing hysteroscopy with endometrial biopsy were enrolled. Biopsies were taken during the midluteal phase. After culture in the presence of embryo-conditioned IVF media, total RNA was extracted and submitted to reverse transcription, target cDNA synthesis, biotin labelling, fragmentation and hybridization using the Affymetrix Human Genome U133A 2.0 Chip. Differential expression of selected genes was re-analysed by quantitative PCR, in which the results were calculated as threshold cycle differences between the groups and normalized to Glyceraldehyde phosphate dehydrogenase and beta-actin. Differences were seen for several genes from endometrial tissue between the IF and the pregnancy groups, and when comparing OP with M, 1875 up- and 1807 down-regulated genes were returned. Real-time PCR analysis confirmed up-regulation for somatostatin, PLAP-2, mucin 4 and CD163, and down-regulation of glycodelin, IL-24, CD69, leukaemia inhibitory factor and prolactin receptor between Op and M. When the different embryo-conditioned media were compared, no significant differential regulation could be demonstrated. Although microarray profiling may currently not be sensitive enough for studying the effects of embryo-derived factors on the endometrium, the observed differences in gene expression between M and OP suggest that it will become an interesting tool for the identification of fertility-relevant markers produced by the endometrium.
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Sequential conversion of estradiol (E) to 2/4-hydroxyestradiols and 2-/4-methoxyestradiols (MEs) by CYP450s and catechol-O-methyltransferase, respectively, contributes to the inhibitory effects of E on smooth muscle cells (SMCs) via estrogen receptor-independent mechanisms. Because medroxyprogesterone (MPA) is a substrate for CYP450s, we hypothesized that MPA may abrogate the inhibitory effects of E by competing for CYP450s and inhibiting the formation of 2/4-hydroxyestradiols and MEs. To test this hypothesis, we investigated the effects of E on SMC number, DNA and collagen synthesis, and migration in the presence and absence of MPA. The inhibitory effects of E on cell number, DNA synthesis, collagen synthesis, and SMC migration were significantly abrogated by MPA. For example, E (0.1micromol/L) reduced cell number to 51+/-3.6% of control, and this inhibitory effect was attenuated to 87.5+/-2.9% by MPA (10 nmol/L). Treatment with MPA alone did not alter any SMC parameters, and the abrogatory effects of MPA were not blocked by RU486 (progesterone-receptor antagonist), nor did treatment of SMCs with MPA influence the expression of estrogen receptor-alpha or estrogen receptor-beta. In SMCs and microsomal preparations, MPA inhibited the sequential conversion of E to 2-2/4-hydroxyestradiol and 2-ME. Moreover, as compared with microsomes treated with E alone, 2-ME formation was inhibited when SMCs were incubated with microsomal extracts incubated with E plus MPA. Our findings suggest that the inhibitory actions of MPA on the metabolism of E to 2/4-hydroxyestradiols and MEs may negate the cardiovascular protective actions of estradiol in postmenopausal women receiving estradiol therapy combined with administration of MPA.
Resumo:
OBJECTIVE: Glycodelin (PP14) is produced by the epithelium of the endometrium and its determination in the serum is used for functional evaluation of this tissue. Given the complex regulation and the combined contraceptive and immunosuppressive roles of glycodelin, the current lack of normal values for its serum concentration in the physiological menstrual cycle, derived from a large sample number, is a problem. We have therefore established reference values from over 600 sera. DESIGN: Retrospective study using banked serum samples. SETTING: University hospital. METHODS: Measurement of blood samples daily or every second day during one full cycle. MAIN OUTCOME MEASURES: Serum concentrations of glycodelin and normal values for every such one- or two-day interval were calculated. Late luteal phase glycodelin levels were compared with ovarian hormones. Follicular phase levels were compared with stimulated cycles from patients undergoing in vitro fertilization. RESULTS: Glycodelin concentrations were low around ovulation. Highest levels were observed at the end of the luteal phase; the glycodelin serum peak was reached 6-8 days after the one for progesterone. Late luteal glycodelin levels correlated negatively with the body mass index and positively with the progesterone level earlier in the secretory (mid-luteal) phase in the same woman. No associations with other ovarian hormones were observed. Follicular phase glycodelin levels were higher in the spontaneous than in the in vitro fertilization cycles. CONCLUSIONS: Normal values taken at two- or one-day intervals demonstrate the very late appearance of high serum glycodelin levels during the physiological menstrual cycle and their correlation with progesterone occurring earlier in the cycle.
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Aldosterone is a key regulator of electrolyte and water homeostasis and plays a central role in blood pressure regulation. Hormonal changes during pregnancy, among them increased progesterone and aldosterone production, lead to the required plasma volume expansion of the maternal body as an accommodation mechanism for fetus growth. This review discusses the regulation of aldosterone production by aldosterone synthase (CYP11B2); the impact on aldosterone secretion due to the presence of a chimeric gene originating from a crossover between CYP11B1 and CYP11B2 in glucocorticoid remediable aldosteronism (GRA) - the inherited form of hypertension; enhanced aldosterone production in aldosterone-producing adenoma (APA); and idiopathic hyperaldosteronism (IHA). Features of hyperaldosteronism are also found in patients with apparent mineralocorticoid excess (AME), in which glucocorticoids exacerbate activation of the mineralocorticoid receptor (MR) because of a defect in the 11beta-hydroxysteroid dehydrogenase type 2 enzyme. Regulation of aldosterone production and tissue-specific activation of the mineralocorticoid receptor are prerequisites for optimal control of body fluids and blood pressure during pregnancy and contribute largely to the wellbeing of the mother-to-be.