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1.
Hum Reprod ; 30(3): 692-700, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25609240

RESUMO

STUDY QUESTION: Does polycystic ovary syndrome (PCOS) in women without pregnancy complications affect placental signal transducer and activator of transcription 3 (STAT3) and mechanistic target of rapamycin (mTOR) signaling? SUMMARY ANSWER: Placental STAT3 signaling is activated but mTOR signaling is unaffected in PCOS. WHAT IS KNOWN ALREADY: Women with PCOS have increased risk of poor pregnancy outcomes (e.g. restricted or accelerated fetal growth), indicating placental dysfunction. Placental STAT3 and mTOR pathways regulate placental function and indirectly affect fetal growth. STUDY DESIGN, SIZE, DURATION: In a case-control study, placental tissue and maternal blood were collected at delivery from 40 control pregnant women and 38 PCOS women with uncomplicated pregnancy. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with PCOS were recruited at two medical centers and pregnant controls were recruited at one of these centers. Placental mRNA expression of genes encoding proteins related to steroid action, metabolic pathways and cytokines was analyzed by quantitative RT-PCR. Phosphorylated placental STAT3 (P-STAT3) and mTOR targets was measured by western blot. Levels of sex steroids in serum were determined by mass spectrometry. MAIN RESULTS AND THE ROLE OF CHANCE: Placental P-STAT3 (Tyr-705) was increased in women with PCOS (P < 0.05) versus controls. Placental mTOR signaling was not affected in PCOS women when compared with controls. Circulating levels of androstenedione, androst-5-ene-3ß, 17ß-diol, testosterone, 5α-dihydrotestosterone and etiocholanolone glucuronide were higher and estradiol lower in women with PCOS than in controls (all P < 0.05). No correlation between sex steroid levels in serum and P-STAT3 was observed. LIMITATIONS, REASONS FOR CAUTION: Women with PCOS and pregnancy complications were excluded to avoid the confounding effects of placental pathologies, which could modify STAT3 and mTOR signaling. Moreover, 97.4% of women with PCOS in the study displayed oligoamenorrhea at diagnosis. Thus, the current findings could be restricted to PCOS women with the oligo-anovulatory phenotype without pregnancy complications. WIDER IMPLICATIONS OF THE FINDINGS: Phosphorylation of STAT3 is increased in the placenta from women with PCOS and uncomplicated pregnancies, indicating that specific metabolic placental pathways are activated in the absence of obstetric and perinatal complications. STUDY FUNDING/COMPETING INTERESTS: The work was supported by the Swedish Medical Research Council (Project No. 2011-2732 and 2014-2775); Jane and Dan Olsson Foundation, Wilhelm and Martina Lundgrens's Science Fund; Hjalmar Svensson Foundation (E.S.-V and M.M.); Adlerbert Research Foundation; Swedish federal government under the LUA/ALF agreement ALFFGBG-136481 and 429501 and the Regional Research and Development agreement (VGFOUREG-5171, -11296 and -7861). MM thanks the Becas Chile Programme (Chile) and University of Chile for financial support through a postdoctoral fellowship. There are no competing interests.


Assuntos
Síndrome do Ovário Policístico/metabolismo , Fator de Transcrição STAT3/metabolismo , Adulto , Estudos de Casos e Controles , Feminino , Expressão Gênica , Humanos , Fosforilação , Gravidez , Resultado da Gravidez , RNA Mensageiro/metabolismo , Transdução de Sinais , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Serina-Treonina Quinases TOR/metabolismo
2.
Climacteric ; 18(6): 817-25, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26517756

RESUMO

OBJECTIVE: The aim was to analyze the opinion of the male partner of women treated for vulvovaginal atrophy (VVA) with intravaginal 0.50% DHEA (prasterone), thus providing information on both members of the couple. METHODS: On a voluntary basis, in a prospective, randomized, double-blind and placebo-controlled phase-III clinical trial, the male partner filled a questionnaire at baseline and at 12 weeks stating his observations related to his penis and intercourse before and after VVA treatment. RESULTS: Sixty-six men having a partner treated with intravaginal DHEA and 34 others having a partner treated with placebo answered the questionnaires. Concerning the feeling of vaginal dryness of their female partner, the severity score following DHEA treatment improved by 81% (0.76 units) over placebo (p = 0.0347). Thirty-six percent of men having a partner treated with DHEA did not feel the vaginal dryness of the partner at the end of treatment compared to 7.8% in the placebo group. When analyzing the situation at 12 weeks compared to baseline, an improved score of 1.09 units was the difference found for the DHEA group compared to 0.76 for the placebo group (p = 0.05 vs. placebo). In the DHEA group, 38% of men scored very improved compared to 18% in the placebo group. No adverse event has been reported. CONCLUSION: The male partner had a very positive evaluation of the treatment received by his female partner.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Desidroepiandrosterona/administração & dosagem , Doenças do Pênis/etiologia , Parceiros Sexuais , Vagina/patologia , Vulva/patologia , Administração Intravaginal , Adulto , Idoso , Idoso de 80 Anos ou mais , Atrofia/complicações , Atrofia/tratamento farmacológico , Coito , Método Duplo-Cego , Dispareunia/etiologia , Eritema/etiologia , Feminino , Fricção/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensação/efeitos dos fármacos , Índice de Gravidade de Doença , Inquéritos e Questionários , Resultado do Tratamento , Vagina/efeitos dos fármacos , Vulva/efeitos dos fármacos
3.
Climacteric ; 18(4): 590-607, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25511551

RESUMO

OBJECTIVE: While daily intravaginal administration of 0.50% (6.5 mg) dehydroepiandrosterone (DHEA, prasterone) for 12 weeks has shown clinically and statistically significant effects on moderate to severe (MS) dyspareunia as the most bothersome symptom (MBS), the present study analyzes the effect of a reduced dosing regimen on MBS vaginal dryness. METHOD: Daily intravaginal 0.50% prasterone for 2 weeks followed by twice weekly for 10 weeks versus placebo. RESULTS: Maximal beneficial changes in vaginal parabasal and superficial cells and pH were observed at 2 weeks as observed for intravaginal 10 µg estradiol (E2). This was followed by a decrease or lack of efficacy improvement after switching to twice-weekly dosing. The decrease in percentage of parabasal cells, increase in percentage of superficial cells and decrease in vaginal pH were all highly significant (p < 0.0001 to 0.0002 over placebo) at 12 weeks. In parallel, the statistical significance over placebo (p value) on MBS vaginal dryness at 6 weeks was 0.09 followed by an increase to 0.198 at 12 weeks. For MBS dyspareunia, the p value of 0.008 at 6 weeks was followed by a p value of 0.077 at 12 weeks, thus illustrating a decrease of efficacy at the lower dosing regimen. The improvements of vaginal secretions, color, epithelial integrity and epithelial surface thickness were observed at a p value < 0.01 or 0.05 over placebo at 2 weeks, with a similar or loss of statistical difference compared to placebo at later time intervals. No significant adverse event was observed. Vaginal discharge related to the melting of Witepsol was reported in 1.8% of subjects. CONCLUSION: The present data show that daily dosing with 0.50% DHEA for 2 weeks followed by twice-weekly dosing is a suboptimal treatment of the symptoms/signs of vulvovaginal atrophy resulting from a substantial loss of the efficacy achieved at daily dosing.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Desidroepiandrosterona/administração & dosagem , Doenças Vaginais/tratamento farmacológico , Doenças da Vulva/tratamento farmacológico , Adjuvantes Imunológicos/uso terapêutico , Administração Intravaginal , Adulto , Idoso , Atrofia/complicações , Atrofia/tratamento farmacológico , Desidroepiandrosterona/uso terapêutico , Método Duplo-Cego , Esquema de Medicação , Dispareunia/tratamento farmacológico , Dispareunia/etiologia , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa , Resultado do Tratamento , Doenças Vaginais/complicações , Doenças da Vulva/complicações
4.
Climacteric ; 16(2): 205-13, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23126249

RESUMO

Menopause has been chosen by evolution as the convergence of three factors, namely cessation of ovarian function (reproduction and estrogen secretion), high circulating dehydroepiandrosterone (DHEA), and intracrine enzymes able to convert DHEA into active sex steroids in peripheral tissues. The arrest of estrogen secretion by the ovaries at menopause causes a decrease of circulating estradiol below the threshold of biological activity, thus eliminating stimulation of the endometrium and risk of endometrial cancer. As much as the arrest of secretion of estradiol by the ovaries is essential to protect the uterus, it is of major importance that sex steroids continue to be made available in most other tissues which need estrogens and/or androgens for their normal functioning. Evolution, through 500 million years, has progressively provided the peripheral tissues with the enzymes able to make androgens and estrogens while high levels of DHEA, the precursor of all sex steroids, have appeared much later with the primates approximately 20 million years ago. All elements were thus in place for the functioning of intracrinology or the cell-specific formation of estrogens and androgens in peripheral tissues from the inactive precursor DHEA, with no significant release of active sex steroids in the circulation, thus eliminating the risks of adverse effects in the other tissues, especially the uterus. The presence of subthreshold levels of circulating estradiol combined with the formation of sex steroids from DHEA in specific peripheral tissues (intracrinology) makes menopause a positive characteristic supporting many years of good-quality postmenopausal life, useful for taking care of children and grandchildren. DHEA, however, decreases with age and is present at very different concentrations between different women, with the consequence that approximately 75% of postmenopausal women have too low circulating DHEA levels and suffer from symptoms/signs of hormone deficiency.


Assuntos
Evolução Biológica , Desidroepiandrosterona/sangue , Menopausa/fisiologia , Adulto , Fatores Etários , Envelhecimento/fisiologia , Androgênios/biossíntese , Desidroepiandrosterona/metabolismo , Endométrio/fisiologia , Estradiol/sangue , Estrogênios/biossíntese , Feminino , Hormônios Esteroides Gonadais/metabolismo , Humanos , Pessoa de Meia-Idade , Ovário/fisiologia , Reprodução/fisiologia , Testosterona/sangue
5.
Nat Genet ; 1(4): 239-45, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1363812

RESUMO

Classical 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4-isomerase (3 beta-HSD) deficiency is an autosomal recessive form of congenital adrenal hyperplasia characterized by a severe impairment of steroid biosynthesis in both the adrenals and the gonads. We describe the nucleotide sequence of the two highly homologous genes encoding 3 beta-HSD isoenzymes in three classic 3 beta-HSD deficient patients belonging to two apparently unrelated pedigrees. No mutation was detected in the type I 3 beta-HSD gene, which is mainly expressed in the placenta and peripheral tissues. Both nonsense and frameshift mutations, however, were found in the type II 3 beta-HSD gene, which is the predominant 3 beta-HSD gene expressed in the adrenals and gonads, thus providing the first elucidation of the molecular basis of this disorder.


Assuntos
3-Hidroxiesteroide Desidrogenases/genética , Hiperplasia Suprarrenal Congênita/enzimologia , Hiperplasia Suprarrenal Congênita/genética , Isoenzimas/genética , Mutação Puntual , 3-Hidroxiesteroide Desidrogenases/metabolismo , Adulto , Sequência de Aminoácidos , Sequência de Bases , Códon/genética , Feminino , Humanos , Isoenzimas/metabolismo , Masculino , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Linhagem , Reação em Cadeia da Polimerase/métodos , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição
6.
Nat Genet ; 27(2): 172-80, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11175785

RESUMO

It is difficult to identify genes that predispose to prostate cancer due to late age at diagnosis, presence of phenocopies within high-risk pedigrees and genetic complexity. A genome-wide scan of large, high-risk pedigrees from Utah has provided evidence for linkage to a locus on chromosome 17p. We carried out positional cloning and mutation screening within the refined interval, identifying a gene, ELAC2, harboring mutations (including a frameshift and a nonconservative missense change) that segregate with prostate cancer in two pedigrees. In addition, two common missense variants in the gene are associated with the occurrence of prostate cancer. ELAC2 is a member of an uncharacterized gene family predicted to encode a metal-dependent hydrolase domain that is conserved among eukaryotes, archaebacteria and eubacteria. The gene product bears amino acid sequence similarity to two better understood protein families, namely the PSO2 (SNM1) DNA interstrand crosslink repair proteins and the 73-kD subunit of mRNA 3' end cleavage and polyadenylation specificity factor (CPSF73).


Assuntos
Cromossomos Humanos Par 17/genética , Proteínas de Neoplasias/genética , Neoplasias da Próstata/genética , Sequência de Aminoácidos , Clonagem Molecular/métodos , DNA Complementar/genética , Efeito Fundador , Ligação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Linhagem , RNA Mensageiro/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Utah
7.
Nat Genet ; 12(3): 333-7, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8589730

RESUMO

Breast carcinoma is the most common malignancy among women in developed countries. Because family history remains the strongest single predictor of breast cancer risk, attention has focused on the role of highly penetrant, dominantly inherited genes in cancer-prone kindreds (1). BRCA1 was localized to chromosome 17 through analysis of a set of high-risk kindreds (2), and then identified four years later by a positional cloning strategy (3). BRCA2 was mapped to chromosomal 13q at about the same time (4). Just fifteen months later, Wooster et al. (5) reported a partial BRCA2 sequence and six mutations predicted to cause truncation of the BRCA2 protein. While these findings provide strong evidence that the identified gene corresponds to BRCA2, only two thirds of the coding sequence and 8 out of 27 exons were isolated and screened; consequently, several questions remained unanswered regarding the nature of BRCA2 and the frequency of mutations in 13q-linked families. We have now determined the complete coding sequence and exonic structure of BRCA2 (GenBank accession #U43746), and examined its pattern of expression. Here, we provide sequences for a set of PCR primers sufficient to screen the entire coding sequence of BRCA2 using genomic DNA. We also report a mutational analysis of BRCA2 in families selected on the basis of linkage analysis and/or the presence of one or more cases of male breast cancer. Together with the specific mutations described previously, our data provide preliminary insight into the BRCA2 mutation profile.


Assuntos
Cromossomos Humanos Par 13 , Mutação , Proteínas de Neoplasias/genética , Fatores de Transcrição/genética , Proteína BRCA2 , Sequência de Bases , Neoplasias da Mama Masculina/genética , Linhagem Celular , Clonagem Molecular , Primers do DNA , Éxons , Feminino , Expressão Gênica , Ligação Genética , Humanos , Masculino , Dados de Sequência Molecular , Neoplasias Ovarianas/genética , Reação em Cadeia da Polimerase , Polimorfismo Genético , Deleção de Sequência
8.
Osteoporos Int ; 22(5): 1513-23, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21052641

RESUMO

SUMMARY: The influence of age and sex steroids on bone density and geometry of the radius was examined in two European Caucasian populations. Age-related change in bone density and geometry was observed. In older men, bioavailable oestradiol may play a role in the maintenance of cortical and trabecular bone mineral density (BMD). INTRODUCTION: To examine the effect of age and sex steroids on bone density and geometry of the radius in two European Caucasian populations. METHODS: European Caucasian men aged 40-79 years were recruited from population registers in two centres: Manchester (UK) and Leuven (Belgium), for participation in the European Male Ageing Study. Total testosterone (T) and oestradiol (E(2)) were measured by mass spectrometry and the free and bioavailable fractions calculated. Peripheral quantitative computed tomography was used to scan the radius at distal (4%) and midshaft (50%) sites. RESULTS: Three hundred thirty-nine men from Manchester and 389 from Leuven, mean ages 60.2 and 60.0 years, respectively, participated. At the 50% radius site, there was a significant decrease with age in cortical BMD, bone mineral content (BMC), cortical thickness, and muscle area, whilst medullary area increased. At the 4% radius site, trabecular and total volumetric BMD declined with age. Increasing bioavailable E(2) (bioE(2)) was associated with increased cortical BMD (50% radius site) and trabecular BMD (4% radius site) in Leuven, but not Manchester, men. This effect was predominantly in those aged 60 years and over. In older Leuven men, bioavailable testosterone (Bio T) was linked with increased cortical BMC, muscle area and SSI (50% radius site) and total area (4% radius site). CONCLUSIONS: There is age-related change in bone density and geometry at the midshaft radius in middle-aged and elderly European men. In older men bioE(2) may maintain cortical and trabecular BMD. BioT may influence bone health through associations with muscle mass and bone area.


Assuntos
Envelhecimento/fisiologia , Densidade Óssea/fisiologia , Hormônios Esteroides Gonadais/fisiologia , Rádio (Anatomia)/fisiologia , Adulto , Idoso , Estudos Transversais , Estradiol/sangue , Estradiol/fisiologia , Hormônios Esteroides Gonadais/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Rádio (Anatomia)/anatomia & histologia , Testosterona/sangue , Testosterona/fisiologia
9.
Climacteric ; 14(2): 282-8, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21244215

RESUMO

OBJECTIVE: To examine the effect of intravaginal dehydroepiandrosterone (DHEA) on pain at sexual activity (dyspareunia) identified as the most bothersome symptom of vaginal atrophy in postmenopausal women at both screening and day 1. METHODS: This prospective, randomized, double-blind and placebo-controlled phase III clinical trial studied the effect of prasterone (DHEA) applied locally in the vagina on the severity of dyspareunia in 114 postmenopausal women who had identified dyspareunia as their most bothersome symptom of vaginal atrophy, while meeting the criteria for superficial cells ≤ 5% and pH > 5.0 at both screening and day 1. RESULTS: At the standard duration of 12 weeks of treatment, increasing doses of 0.25%, 0.5% and 1.0% DHEA decreased the percentage of parabasal cells by 48.6  ±â€Š 6.78%, 42.4  ±  7.36% and 54.9  ±â€Š 6.60% (p < 0.0001 vs. placebo for all) with no change with placebo (p = 0.769). The effects on superficial cells and pH were also highly significant compared to placebo at all DHEA doses. The severity score of pain at sexual activity decreased by 0.5, 1.4, 1.6 and 1.4 units in the placebo and 0.25%, 0.5% and 1.0% DHEA groups, respectively, with the p value of differences from placebo ranging from 0.0017 to < 0.0001. CONCLUSIONS: Intravaginal DHEA, through local estrogen and androgen formation, causes a rapid and highly efficient effect on pain at sexual activity without systemic exposure of the other tissues, thus avoiding the recently reported systemic effects of estrogens.


Assuntos
Desidroepiandrosterona/administração & dosagem , Dispareunia/tratamento farmacológico , Administração Intravaginal , Desidroepiandrosterona/uso terapêutico , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Pós-Menopausa , Resultado do Tratamento
10.
Osteoporos Int ; 21(8): 1331-9, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20012940

RESUMO

SUMMARY: The influence of sex steroids on calcaneal quantitative ultrasound (QUS) parameters was assessed in a population sample of middle-aged and elderly European men. Higher free and total E(2) though not testosterone, were independently associated with higher QUS parameters. INTRODUCTION: The aim of this study was to investigate the association between QUS parameters and sex steroids in middle-aged and elderly European men. METHODS: Three thousand one hundred forty-one men aged between 40 and 79 years were recruited from eight European centres for participation in a study of male ageing: the European Male Ageing Study. Subjects were invited by letter to attend for an interviewer-administered questionnaire, blood sample and QUS of the calcaneus (Hologic-SAHARA). Blood was assessed for sex steroids including oestradiol (E(2)), testosterone (T), free and bio-available E(2) and T and sex hormone binding globulin (SHBG). RESULTS: Serum total T was not associated with any of the QUS parameters. Free T and both free and total E(2) were positively related to all QUS readings, while SHBG concentrations were negatively associated. These relationships were observed in both older and younger (<60 years) men. In a multivariate model, after adjustment for age, centre, height, weight, physical activity levels and smoking, free E(2) and SHBG, though not free T, remained independently associated with the QUS parameters. After further adjustment for IGF-1, however, the association with SHBG became non-significant. CONCLUSION: Higher free and total E(2) are associated with bone health not only among the elderly but also middle-aged European men.


Assuntos
Calcâneo/diagnóstico por imagem , Hormônios Esteroides Gonadais/sangue , Adulto , Idoso , Envelhecimento/sangue , Envelhecimento/fisiologia , Estatura/fisiologia , Peso Corporal/fisiologia , Calcâneo/fisiologia , Estradiol/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora/fisiologia , Globulina de Ligação a Hormônio Sexual/metabolismo , Fumar/sangue , Testosterona/sangue , Ultrassonografia
11.
Br J Dermatol ; 163(5): 968-76, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20698844

RESUMO

BACKGROUND: Although low dehydroepiandrosterone (DHEA) is suspected to have a role in skin ageing, little information is available on the mechanisms potentially involved. OBJECTIVES: To obtain information on androgen receptor (AR) and procollagen expression in ageing skin during DHEA treatment. METHODS: A placebo-controlled, randomized, prospective study was performed with 75 postmenopausal women aged 60-65 years. The women were treated twice daily for 13 weeks with 3·0 mL of placebo or 0·1%, 0·3%, 1% or 2% DHEA cream applied on the face, arms, back of hands, upper chest and right thigh where 2-mm biopsies were collected before and after treatment. RESULTS: Although the overall structure of the epidermis was not significantly affected at the light microscopy level, AR expression examined by immunocytochemistry was markedly increased by DHEA treatment. In the dermis, the expression levels of procollagen 1 and 3 mRNA estimated by in situ hybridization were increased by DHEA treatment. In addition, the expression of heat shock protein (HSP) 47, a molecule believed to have chaperone-like functions potentially affecting procollagen biosynthesis, was also found by immunocytochemistry evaluation to be increased, especially at the two highest DHEA doses. CONCLUSION: These data suggest the possibility that topical DHEA could be used as an efficient and physiological antiageing skin agent.


Assuntos
Desidroepiandrosterona/farmacologia , Fármacos Dermatológicos/farmacologia , Derme/efeitos dos fármacos , Epiderme/efeitos dos fármacos , Envelhecimento da Pele/efeitos dos fármacos , Administração Tópica , Idoso , Biópsia , Derme/metabolismo , Derme/patologia , Epiderme/metabolismo , Epiderme/patologia , Feminino , Proteínas de Choque Térmico HSP47/metabolismo , Humanos , Imuno-Histoquímica , Hibridização In Situ , Pessoa de Meia-Idade , Pós-Menopausa/efeitos dos fármacos , Pós-Menopausa/fisiologia , Pró-Colágeno/metabolismo , Estudos Prospectivos , RNA Mensageiro/metabolismo , Receptores Androgênicos/metabolismo , Envelhecimento da Pele/fisiologia
12.
J Cell Biol ; 86(2): 377-87, 1980 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6772648

RESUMO

The secretion of prolactin in cultured pituitary cells was studied in correlation with the cellular changes induced by stimulatory or inhibitory agents. The techniques used in this study were: radioimmunoassay, immunocytochemistry, scanning (SEM) as well as transmission (TEM) electron microscopy. Prolactin secretion was stimulated by 17 beta-estradiol (10 nM) as well as thyrotropin-releasing hormone (TRH) (3 nM) and inhibited by 2-Br-alpha-ergocryptine (CB-154) (1 muM). The total prolactin (release and cell content) increased between 2 and 8 d of estradiol treatment, indicating an increase of both synthesis and release of prolactin. This finding was in agreement with TEM observations because, in estradiol-treated prolactin cells, the Golgi saccules were distended and Golgi elements were increased, thus indicating increased synthetic activity of these cells. The addition of TRH over a 4-h period resulted in a significant degranulation of prolactin cells. In contrast, prolactin secretory granules became accumulated in the cells after CB-154 treatment for a period ranging from 4 to 24 h. In agreement, light microscope immunocytochemistry showed an increased reaction for prolactin after short-term (< 24 h) incubation with CB-154. Because prolactin cells represent approximately 70% of the glandular cell population as revealed by immunocytochemistry, it was then possible to observe the changes of cell surface by SEM. In most cells, estradiol and TRH led to an increase in the number and prominence of microvilli and blebs, whereas CB-154 treatment resulted in a slightly decreased number of microvilli and an increased occurrence of membrane foldings. This report thus provides morphological evidence for the stimulatory effects of estradiol and TRH, and the inhibitory effects of CB-154 on prolactin secretion in pituitary cells in primary culture. These data, moreover, show that acute changes in secretory activity of prolactin-secreting cells are accompanied by marked changes of their morphological characteristics.


Assuntos
Bromocriptina/farmacologia , Estradiol/farmacologia , Adeno-Hipófise/efeitos dos fármacos , Prolactina/metabolismo , Hormônio Liberador de Tireotropina/farmacologia , Animais , Núcleo Celular/ultraestrutura , Células Cultivadas , Interações Medicamentosas , Técnicas Imunológicas , Microscopia Eletrônica , Adeno-Hipófise/citologia , Adeno-Hipófise/metabolismo , Ratos
13.
Science ; 200(4346): 1173-5, 1978 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-418505

RESUMO

Prior incubation of rat anterior pituitary cells with 17beta-estradiol led to an almost complete reversal of the inhibitory effect of two dopamine agonists, dihydroergocornine and RU 24213, on both basal prolactin release and thyrotropin releasing hormone-induced prolactin release. These experiments thus demonstrate a direct interference of dopamine action by a peripheral hormone. Prolactin secretion by pituitary cells in primary culture could possibly serve as an easily accessible model of a system under dopaminergic control.


Assuntos
Antagonistas de Dopamina , Estradiol/farmacologia , Adeno-Hipófise/efeitos dos fármacos , Prolactina/metabolismo , Animais , Células Cultivadas , Di-Hidroergotoxina/antagonistas & inibidores , Feminino , Fenetilaminas/antagonistas & inibidores , Adeno-Hipófise/metabolismo , Ratos , Hormônio Liberador de Tireotropina/farmacologia
14.
Science ; 217(4554): 62-3, 1982 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-6283632

RESUMO

Administration of synthetic ovine corticotropin-releasing factor led to rapid, parallel increases in adrenocorticotropin and alpha-melanocyte-stimulating hormone concentrations in rat plasma. Prior treatment with dexamethasone almost completely blocked the adrenocorticotropin response but not the increase in melanocyte-stimulating hormone. These data demonstrate that corticotropin-releasing factor is a potent stimulator not only of adrenocorticotropin secretion from the corticotrophs of the anterior pituitary gland but also of peptide secretion from the intermediate lobe. Such data suggest that melanocyte-stimulating hormone and beta-endorphin play a role in the physiological response to stress.


Assuntos
Hormônio Liberador da Corticotropina/farmacologia , Hormônios Estimuladores de Melanócitos/metabolismo , Hipófise/metabolismo , Hormônio Adrenocorticotrópico/sangue , Animais , Castração , Dexametasona/farmacologia , Feminino , Hormônios Estimuladores de Melanócitos/sangue , Hipófise/efeitos dos fármacos , Adeno-Hipófise/metabolismo , Ratos , Ratos Endogâmicos
15.
Science ; 216(4549): 1007-8, 1982 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-6281886

RESUMO

The presence of synthetic ovine corticotropin-releasing factor leads to a rapid and marked stimulation of adenosine 3', 5'-monophosphate accumulation in an enriched population of rat pituitary corticotrophs in primary culture. The increase, observed as early as 60 seconds after the addition of corticotropin-releasing factor, suggests that changes in the intracellular concentration of the cyclic nucleotide coincide with or precede the secretion of adrenocorticotropic hormone in response to corticotropin-releasing factor.


Assuntos
Hormônio Adrenocorticotrópico/metabolismo , Hormônio Liberador da Corticotropina/farmacologia , AMP Cíclico/metabolismo , Adeno-Hipófise/efeitos dos fármacos , Adeno-Hipófise/metabolismo , Animais , Feminino , Cinética , Ratos
16.
Endocr Rev ; 7(1): 67-74, 1986 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3514203

RESUMO

It is now well established that chronic treatment with GnRH agonists offers an advantageous alternative to orchiectomy and estrogens for the treatment of prostate cancer. Castration levels of androgens can thus be easily achieved without side effects other than those related to castration levels of serum androgens. However, man is unique among species in having a high secretion rate of precursor adrenal steroids which are converted into active androgens in the normal prostate and prostatic cancer. All the enzymes required for the transformation of dehydroepiandrosterone sulfate, dehydroepiandrosterone, androstenedione, and androst-5-ene-3 beta, 17 beta-diol are present in prostatic tissue. Moreover, as shown in many systems, castration levels of serum testosterone (T) at 0.2-0.4 ng/ml exert significant androgenic activity in target tissues. In order to inhibit the action of androgens of both testicular and adrenal origin, GnRH agonists have been administered in association with the pure antiandrogen Flutamide in patients having clinical stage D2 (bone metastases) prostate cancer. A positive objective response assessed according to the criteria of the United States National Prostatic Cancer Project (USNPCP) has been observed in 84 of the 88 patients who had received no previous treatment (95.4%). After 2 yr of treatment, the probability of continuing response is 70% compared to 0-10% by previous approaches. In addition, the death rate at 2 yr is at 10.9% as compared to approximately 50% after standard hormonal therapy. When the same treatment was applied to patients who had received previous hormonal therapy (orchiectomy, estrogens or GnRH agonists alone) before showing a relapse, the response rate decreased to 62.9% and the death rate at 2 yr was 52%.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Hormônios Liberadores de Hormônios Hipofisários/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Antagonistas de Androgênios/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Di-Hidrotestosterona/análise , Estrogênios/uso terapêutico , Flutamida/administração & dosagem , Humanos , Hormônio Luteinizante/sangue , Masculino , Orquiectomia , Hormônios Liberadores de Hormônios Hipofisários/administração & dosagem , Radioimunoensaio , Testosterona/sangue
17.
J Steroid Biochem Mol Biol ; 108(1-2): 102-8, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17933518

RESUMO

Dehydroepiandrosterone (DHEA), the major steroid precursor of androgens and estrogens produced in peripheral tissues in primates, has been shown to exert chemopreventive effect on the development of carcinogen-induced rat mammary tumors. Since little is known on the effect of DHEA administration on mammary gland physiology and histology, we have studied the effect of long-term administration of DHEA to normal female monkey and rat on mammary gland histology as well as on serum DHEA, DHEA sulphate (DHEA-S), testosterone and estradiol levels. In monkeys, DHEA treatment (2 or 10 mg/(kg b.w.day)) induced a dose-related increase in serum DHEA and DHEA-S (above 20-fold) levels. At the highest dose of DHEA, serum testosterone levels were significantly increased (three- to fourfold), while serum estradiol concentration was not modified. DHEA treatment did not modify the histological characteristics of monkey mammary glands. In the rat, following DHEA administration (10 or 100 mg/(kg b.w.day)), a dose-related marked increase in serum DHEA and DHEA-S was observed. Serum testosterone was also increased in DHEA-treated animals, while no significant changes in serum estradiol levels were detected. As in the monkey, the histology of the female rat mammary gland remained unchanged following long-term treatment with any of the two doses of DHEA.


Assuntos
Desidroepiandrosterona/farmacologia , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/efeitos dos fármacos , Administração Oral , Animais , Desidroepiandrosterona/administração & dosagem , Desidroepiandrosterona/sangue , Avaliação Pré-Clínica de Medicamentos , Feminino , Macaca fascicularis , Ratos , Ratos Sprague-Dawley , Esteroides/sangue , Fatores de Tempo
18.
J Steroid Biochem Mol Biol ; 112(4-5): 186-93, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19013239

RESUMO

The objective of this study was to explore, for the first time, the changes in the pangenomic profile induced in human skin in women treated with dehydroepiandrosterone (DHEA) applied locally. Sixty postmenopausal women participated in this phase II prospective, randomized, double-blind and placebo-controlled study. Women were randomized to the twice daily local application of 0% (placebo), 0.3%, 1% or 2% DHEA cream. Changes in the pangenomic expression profile were studied using Affymetrix Genechips. Significant changes (p<0.05) in sixty-six DHEA-responsive probe sets corresponding to 52 well-characterized genes and 9 unknown gene sequences were identified. A dose-dependent increase in the expression of several members of the collagen family was observed, namely COL1, COL3 and COL5 as well as the concomitant modulation of SPARC, a gene required for the normal deposition and maturation of collagen fibrils in the dermis. Several genes involved in the proliferation and differentiation of keratinocytes were also modulated. In addition, topical DHEA reduced the expression of genes associated with the terminal differentiation and cornification of keratinocytes. Our results strongly suggest the possibility that DHEA could exert an anti-aging effect in the skin through stimulation of collagen biosynthesis, improved structural organization of the dermis while modulating keratinocyte metabolism.


Assuntos
Desidroepiandrosterona/farmacologia , Perfilação da Expressão Gênica , Pós-Menopausa/fisiologia , Pele/metabolismo , Administração Tópica , Idoso , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Queratinócitos/citologia , Pessoa de Meia-Idade , Pós-Menopausa/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Pele/efeitos dos fármacos
19.
J Steroid Biochem Mol Biol ; 112(4-5): 194-200, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18996480

RESUMO

Estrogens play an important role in the development and progression of breast cancer. 17beta-Hydroxysteroid dehydrogenase (17beta-HSD) type 2 and type 5 are involved in sex steroid metabolism. 17beta-HSD type 2 converts estradiol to estrone while 17beta-HSD type 5 converts androstenedione to testosterone. Using immunocytochemistry, we have studied the expression of 17beta-HSD type 2 and type 5 in 50 specimens of breast carcinoma and adjacent non-malignant tissues. The results were correlated with the estrogen receptor alpha (ERalpha) and beta (ERbeta), progesterone receptor A (PRA) and B (PRB), androgen receptor and CDC47 and with the tumor stage, tumor size, nodal status and menopausal status. 17beta-HSD type 2 was expressed in 20% and 17beta-HSD type 5 in 56% of breast cancer specimens. In adjacent normal tissues, both enzymes were highly expressed in almost all the patients. No significant association could be found between the expression of 17beta-HSD type 2 and 17beta-HSD type 5 and between the expression of each enzyme and the clinicopathological parameters studied. The decrease in 17beta-HSD type 2 and 17beta-HSD type 5 expressions in breast cancer may play a predominant role in the development and/or progression of the cancer by modifying the intratumoral levels of estrogens and androgens.


Assuntos
17-Hidroxiesteroide Desidrogenases/biossíntese , Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Mama/enzimologia , 3-Hidroxiesteroide Desidrogenases , Adulto , Idoso , Membro C3 da Família 1 de alfa-Ceto Redutase , Animais , Estradiol Desidrogenases , Receptor alfa de Estrogênio/biossíntese , Receptor beta de Estrogênio/biossíntese , Feminino , Humanos , Hidroxiprostaglandina Desidrogenases , Pessoa de Meia-Idade , Coelhos , Receptores Androgênicos/biossíntese , Receptores de Progesterona/biossíntese
20.
Neuroscience ; 145(1): 110-5, 2007 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-17207581

RESUMO

The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) converts the inactive 11-dehydrocorticosterone into the active glucocorticoid corticosterone. There is accumulating evidence indicating widespread expression of 11beta-HSD1 in the brain. However, there is little information about regulation of 11beta-HSD1 expression in this tissue. Using in situ hybridization involving use of 35S-labeled cRNA probe, we have studied the distribution of cells expressing 11beta-HSD1 mRNA in the male mouse forebrain as well as the effects of adrenalectomy (ADX) and acute administration of corticosterone (3 and 24 h) on 11beta-HSD1 mRNA levels. Cells expressing 11beta-HSD1 mRNA were mostly detected in the cerebral cortex, hippocampus, amygdala and medial preoptic area, with the highest expression in the cerebral cortex (retrosplenial granular area) and hippocampus (CA3 and granular layer of the gyrus dentatus). Seven days following ADX, 11beta-HSD mRNA levels were increased by 50% in the gyrus dentatus, by 100% in the CA3 area, and 105% in the cerebral cortex. Administration of corticosterone to ADX mice induced a significant decrease in mRNA, in both the hippocampus and cerebral cortex so that, at the 24 h time interval, the levels were similar to those observed in intact mice. These results clearly indicate that circulating corticosterone is downregulating the expression of 11beta-HSD1 mRNA in the two forebrain areas studied. This downregulation might contribute to maintain low intracellular corticosterone levels in central regions and then prevent the deleterious effects induced by high glucocorticoid levels.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glucocorticoides/farmacologia , Prosencéfalo/enzimologia , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/genética , Adrenalectomia/métodos , Animais , Relação Dose-Resposta a Droga , Hibridização In Situ/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/metabolismo , Fatores de Tempo
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