Mutações inativadoras do receptor de GnRH (GNRHR) são a causa genética mais frequente de hipogonadismo hipogonadotrófico isolado (HHI) normósmico. Os genes envolvidos da patogênese do HHI, incluindo o GNRHR, estão associados a um amplo espectro fenotípico, variando de HHI parcial a completo. O atraso constitucional do crescimento e desenvovimento (ACCD) poderia constituir uma variante fenotípica leve do HHI. Neste estudo avaliamos a frequência de mutações no gene GNRHR em pacientes com HHI normósmico e ACCD, bem como correlacionamos o genótipo/fenótipo nesses pacientes. Além disso, avaliamos o efeito fundador de uma mutação do GNRHR (p.R139H) frequente na população brasileira com HHI normósmico. Para esse estudo, selecionamos 116 pacientes com HHI normósmico e 51 com ACCD. Um grupo de 130 indivíduos com desenvolvimento puberal normal foi utilizado como controle. A região codificadora do gene GNRHR foi amplificada por PCR e sequenciada. Análises in silico e in vitro foram realizadas nas duas novas variantes (p.V134G e p.Y283H). Três marcadores de microssatélites (D4S409, D4S2387, D4S3018) foram amplificados e analisados nos pacientes portadores da mutação p.R139H, familiares e controles. No grupo de HHI normósmico, nove mutações (p.N10K,p.Q11K, p.Q106R, p.R139H, p.C200Y, p.R262Q, p.Y284C, p.Y283H, p.V134G) foram identificadas em onze pacientes (9,5%). Entre as mutações identificadas no GNRHR, duas foram descritas pela primeira vez no estudo atual: p.Y283H e p.V134G, cuja análise in vitro demonstrou inativação completa do receptor. Em geral, uma boa correlação genótipo-fenótipo foi observada. Pacientes portadores de mutações inativadoras apresentavam HHI completo e mutações com perda parcial de função causavam HHI parcial, incluindo dois pacientes que evoluíram com reversão do hipogonadismo após reposição androgênica. Por outro lado, não houve diferença fenotípica entre os casos com e sem mutação do GNRHR. Análise de ancestralidade genética da mutação p.R139H demonstrou que todos os casos brasileiros apresentaram o mesmo haplótipo, sugerindo que a mutação p.R139H possui um ancestral comum na população brasileira. Por outro lado o caso familial proveniente da Polônia apresentou apenas um marcador em comum com as famílias brasileiras e estudos mais abrangentes seriam necessários para determinar a origem da mutação p.R139H em indivíduos não Brasileiros. Na casuística de ACCD apenas a mutação p.Q106R foi identificada no gene GNRHR em heterozigose em um paciente. Em conclusão, o GNRHR foi o gene mais comumente afetado, apresentando uma boa correlação genótipo-fenótipo, e deve ser o primeiro candidato para análise genética em HHI normósmico. Os resultados sugerem que a mutação p.R139H possui um ancestral comum na população brasileira. Mutações no GNRHR parecem não estar envolvidas na patogênese do ACCD / GnRH receptor (GNRHR) inactivating mutations are the most common genetic cause of normosmic IHH. The genes involved in the IHH, including GNRHR, have been associated with a large phenotypic spectrum, varying from partial to complete IHH. Constitutional delay of growth and puberty (CDGP) might represent a mild phenotypic variant of IHH. In this study we investigated novel variants and characterized the frequency and phenotype-genotype correlation of GNRHR mutations in normosmic IHH and CDGP patients. Additionally, we determined de cause of the recurrence of GNRHR p.R139H mutation in patients with normosmic IHH. We studied 116 patients with normosmic IHH and 51 with CDGP. The control group was composed by 130 adults with normal pubertal development. The coding region of GNRHR was amplified and automatically sequenced. The two novel variants identified (p.Y283H, p.V134G) were submitted to in silico and in vitro analysis. Three microsatellite markers (D4S409, D4S2387, D4S3018) were amplified by PCR and analyzed in the patients with the p.R139H mutation. In the CDGP group, the previously described mutation p.Q106R was identified in the heterozygous state in one boy. The p.Q106R mutation has been identified in heterozygous state in individuals with normal pubertal development and does not appear be involved on the CDGP phenotype in this patient. In the normosmic IHH group, nine variants were identified (p.N10K, p.Q11K, p.Q106R, p.R139H, p.C200Y, p.R262Q, p.Y284C, p.Y283H, p.V134G) in eleven patients (9.5%). In vitro analysis of the novel variants p.Y283H and the p.V134G demonstrated that both of them cause complete loss of function of the receptor. The founder effect study revealed that all the p.R139H affected Brazilian patients presented the same haplotype, suggesting that the this mutation has a common ancestor in the Brazilian population. Nevertheless the affected Polish family presented a different haplotype, with only one marker in common with the Brazilian families and further studies would be necessary to determine the origin of the p.R139H mutation in the European population. In conclusion this study demonstrated that GNRHR was the most commonly affected gene in normosmic IHH, with a good genotype-phenotype correlation, and should be the first candidate gene for genetic screening in this condition. The results of the founder effect study suggested that the p.R139H mutation has a common ancestor in the Brazilian population. Finally, mutations in the GNRHR do not appear to be involved in the pathogenesis of CDGP

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on January 6, 2010). Thesis advisor: M. Cathleen Kuehl-Kovarik. Includes bibliographical references.

Hermaphroditism, associated with territoriality and dominance behavior, is common in the marine environment. Male sex-specific coloration patterns and behavior are particularly evident in species where males are territorial and guard harems of females such as wrasses and groupers. Protogynous hermaphrodites that change sex from female to male are good models to study sexual behavior and related changes in the brain due to their abilities to reorganize their sexual phenotype as adults. Two hormones produced in the brain and implicated in the process of sex-specific behavior and reproductive development are arginine vasotocin (AVT) and gonadotropin releasing hormone (GnRH). While a wealth of data exists regarding these hormone systems separately, little is known about linkage between these two systems. Especially there is no data tracking these two systems together in any protogynous fish. This study was conducted to test the hypothesis that coordinated interactions between AVT and GnRH facilitate the process of behavioral and gonadal sex change in the rock hind Epinephelus adscensionis. Four topics were addressed to investigate the relationship between behavior and reproduction: i) rock hind sex change, sexual characteristics and conditions causing sex change to occur in captivity were detailed as a basis for examining the AVT system and GnRH during this process, ii) the distribution of a vasotocin V1a type receptor identified in rock hind brain was examined for the first time in a fish species using a custom designed antibody then the receptor protein was co-localized with GnRH producing cells within the brain to confirm that a pathway exists for AVT action on GnRH, iii) levels of AVT, AVT receptors, and GnRH messenger RNA (mRNA) were compared between male and female rock hind phenotypes, and iv) female rock hind at early stages of sex change were compared for brain mRNA expression of AVT, AVT receptors, and GnRH to determine the order of hormonal change during the process of sexual inversion in this species. This study provides a better understanding of the relationship between sex-specific behavior and reproductive development via AVT and GnRH systems that are conserved in all vertebrates. / text

Die Implantation einer Blastozyste im Uterus stellt für den maternalen Organismus eine große Herausforderung dar. Neben morphologischen Veränderungen des Endometriums sind Anpassungen auch im Immun- und Gefäßsystem notwendig. Kenntnisse über die verantwortlichen Faktoren für diese Prozesse sind bei Menschen und anderen Primaten noch immer unvollständig. Dabei sind Implantationsstörungen oftmals Ursache von Fruchtbarkeitsproblemen (SHARKEY und SMITH 2003). Besonders im Bereich der assistierten Reproduktion stellen implantationsbedingte Probleme eine Hauptursache für geringe Erfolgsraten dar (APLIN und KIMBER 2004). Das Ziel der Erforschung von Mechanismen im Zusammenhang mit der Implantation ist es, ein besseres Verständnis für die physiologischen und auch pathologischen Vorgänge zu erlangen. In dessen Folge die Erkenntnisse für die Behandlung von Implantationsstörungen genutzt werden könnten. Anhand des in der reproduktionsbiologischen Forschung etablierten Primatenmodells des Weißbüschelaffen (Callithrix jacchus) wurde in der vorliegenden Arbeit die Expression ausgewählter Faktoren in verschiedenen Zyklusphasen mit dem Schwerpunkt der Implantationsphase untersucht. Dafür wurden zeitlich genau terminierte Uterusproben von konzeptiven und nicht-konzeptiven Tieren entnommen und molekularbiologisch, histologisch und immunhistochemisch analysiert. Erstmals konnte im Uterus von Weißbüschelaffen die zeitliche und räumliche Regulierung von Choriongonadotropin (CG), Östradiolrezeptor-α (ERα), Östradiolrezeptor-ß (ERß), Progesteronrezeptor (PR), Aromatase (ARO), 17β-Hydroxysterois-Dehydrogenase Typ 7 (17β-HSD7) sowie Relaxin (RLN) und Relaxinrezeptor (RXFP1) auf Gen- und Proteinebene in verschiedenen Zyklusphasen in der vorliegenden Vollständigkeit dargestellt werden. Alle in dieser Arbeit untersuchten Faktoren zeigten eine rezeptorspezifische Veränderung der Expressionsmuster, auf räumlicher und zeitlicher Ebene im Verlauf des Implantationsprozesses. Es konnte dargestellt werden, dass die feto-maternale Kommunikation bereits vor dem direkten Kontakt der Blastozyste mit dem Endometrium beginnt. So wurde bei konzeptiven Tieren eine verstärkte Expression von CG, ERα, PR, 17β-HSD7 und RXFP1 in der Implantationsphase nachgewiesen. Diese Faktoren sind geeignete Kandidaten für weiterführende Untersuchungen und Evaluierung von Markern für die Präimplantationsphase und rezeptiven Uteri von Weißbüschelaffen. Die ebenfalls untersuchten Faktoren ERβ, ARO und RLN zeigten Expressionsmuster, welche erst nach der Implantation bei konzeptiven Tieren Unterschiede aufwiesen. Aus diesem Grund sind diese Faktoren nicht als frühe Marker der Implantationsphase geeignet, gleichwohl sie wichtige Funktionen in der Postimplantationsphase übernehmen. Die Ergebnisse dieser Arbeit verdeutlichen, dass nicht alleine ein einzelner Faktor eine herausragende Bedeutung im Implantationsprozess hat, sondern vielmehr ein äußerst komplexes Netzwerk von Signalen nötig ist, um eine erfolgreiche Gravidität zu gewährleisten. Die Aufgabe der Steroidrezeptoren ERα und PR liegt in der grundlegenden Bereitstellung eines rezeptiven Uterus während des Implantationszeitfensters. Gleichzeitig erfolgt eine sehr genau koordinierte Regulation dieser Steroidrezeptoren über die lokal produzierten Faktoren CG, ARO, 17β-HSD7, RLN und der Rezeptoren RXFP1 und ERβ. Neben den morphologischen Veränderungen des Endometriums, sind einzelne Faktoren auch bei der Angiogenese und Entwicklung der maternalen Immuntoleranz beteiligt. Es kann demnach davon ausgegangen werden, dass die präzise Regulation dieser Faktoren eine essentielle Voraussetzung für den Erfolg der Implantation und Gravidität ist.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Made available in DSpace on 2015-04-09T12:28:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-03Bitstream added on 2015-04-09T12:48:07Z : No. of bitstreams: 1 000815988.pdf: 670904 bytes, checksum: df849f5b7af31dd25a1aabd5ab80b4cd (MD5) / O Brasil é o país com a maior diversidade de psitacídeos do mundo, abrigando 72 espécies reconhecidas, com 16 espécies presentes no “Livro Vermelho da Fauna Brasileira Ameaçada de Extinção”. O papagaio-verdadeiro (Amazona aestiva) se destaca por sua popularidade como animal de estimação, sendo coletado na natureza em grande número para atender ao mercado ilegal de animais silvestres. Sua reprodução em cativeiro pode se tornar uma ferramenta para a conservação das populações na natureza, porém isso exige uma criação baseada em conhecimentos científicos e técnicas avançadas de reprodução. Esta tese teve como objetivos apresentar o perfil anual endócrino dos esteroides sexuais do Amazona aestiva e realizar um ensaio de estímulo hormonal através da aplicação de análogo de GnRH de liberação lenta na espécie. Utilizamos 10 casais e 4 machos adultos da espécie Amazona aestiva mantidos em viveiros suspensos, pertencentes ao Criadouro da Brisa, situado Jaboticabal/SP. As excretas foram coletadas ao menos uma vez por semana entre junho de 2011 e julho de 2012 para entendimento dos processos endócrinos que regem a reprodução da espécie e entre agosto de 2012 e dezembro de 2012 no ensaio de estímulo hormonal. O monitoramento da atividade gonadal foi feita de forma não invasiva por mensuração de metabólitos de andrógenos nas excretas dos machos e de progestágenos nas excretas de fêmeas. Foram coletadas amostras frescas de excretas, sempre no período entre 14h as 17h, e mantidas congeladas até o processamento. As amostras foram secas em estufa a 57oC, trituradas e os hormônios extraídos utilizando metanol a 80%. A dosagem hormonal foi realizada no Laboratório de Endocrinologia do NUPECCE (Núcleo de Pesquisa e Conservação de Cervídeos) utilizando ensaio imunoenzimático com o anticorpo para andrógenos e progestágenos. No ensaio de estimulo hormonal exógeno com analago de GnRH foi aplicado ... / Brazil is the country with the greatest diversity of parrots in the world , with to 72 recognized species , with 16 species in the Red List of Endangered Brazilian Wild Animals . The blue-fronted amazon parrot ( Amazona aestiva ) stands out for its popularity as a pet , being collected from the wild in large numbers to attend the illegal market for wildlife. His captive breeding can become a tool for the conservation of populations in nature , but this requires a creation based on scientific knowledge and advanced breeding techniques . This thesis aimed to present the annual endocrine profile of sex steroids of Amazona aestiva and a test of hormonal stimulation by applying GnRH analogue of the slow release. It was used 10 couples and 4 adult males of Amazona aestiva kept in suspended cages, properties of the commercial breeder “Criadouro da Brisa”, located in Jaboticabal / SP. The droppings were collected at least once a week between June 2011 and July 2012 for the understanding of endocrine processes of the reproduction in this specie and between August 2012 and December 2012 for testing hormonal stimulation . The monitoring of gonadal activity was noninvasively by measuring androgen metabolites in droppings of males and females of droppings progestogens. Fresh droppings samples were collected , always in between 14h to 17h , and kept frozen until processing . The samples were dried at 57oC, crushed and hormones were extracted using 80% methanol . The hormone dosage was performed at the Laboratory of Endocrinology, NUPECCE ( Center for Research and Conservation of Deer ) using enzyme immunoassay with antibody to androgens and progestins . In exogenous hormone stimulation test with GnRH was applied analago buserelin slow release in 5 couples and 5 couples were used to control the following excreta collection , processing and hormonal dosage previously described . The results of the annual listing of androgens in males ...

Orientador: José Mauricio Barbanti Duarte / Banca: Lindsay Unno Gimenes / Banca: Eveline dos Santos Zanetti / Banca: Denise Calisto Bongalhardo / Banca: Ricardo José Garcia Pereira / Resumo: O Brasil é o país com a maior diversidade de psitacídeos do mundo, abrigando 72 espécies reconhecidas, com 16 espécies presentes no "Livro Vermelho da Fauna Brasileira Ameaçada de Extinção". O papagaio-verdadeiro (Amazona aestiva) se destaca por sua popularidade como animal de estimação, sendo coletado na natureza em grande número para atender ao mercado ilegal de animais silvestres. Sua reprodução em cativeiro pode se tornar uma ferramenta para a conservação das populações na natureza, porém isso exige uma criação baseada em conhecimentos científicos e técnicas avançadas de reprodução. Esta tese teve como objetivos apresentar o perfil anual endócrino dos esteroides sexuais do Amazona aestiva e realizar um ensaio de estímulo hormonal através da aplicação de análogo de GnRH de liberação lenta na espécie. Utilizamos 10 casais e 4 machos adultos da espécie Amazona aestiva mantidos em viveiros suspensos, pertencentes ao Criadouro da Brisa, situado Jaboticabal/SP. As excretas foram coletadas ao menos uma vez por semana entre junho de 2011 e julho de 2012 para entendimento dos processos endócrinos que regem a reprodução da espécie e entre agosto de 2012 e dezembro de 2012 no ensaio de estímulo hormonal. O monitoramento da atividade gonadal foi feita de forma não invasiva por mensuração de metabólitos de andrógenos nas excretas dos machos e de progestágenos nas excretas de fêmeas. Foram coletadas amostras frescas de excretas, sempre no período entre 14h as 17h, e mantidas congeladas até o processamento. As amostras foram secas em estufa a 57oC, trituradas e os hormônios extraídos utilizando metanol a 80%. A dosagem hormonal foi realizada no Laboratório de Endocrinologia do NUPECCE (Núcleo de Pesquisa e Conservação de Cervídeos) utilizando ensaio imunoenzimático com o anticorpo para andrógenos e progestágenos. No ensaio de estimulo hormonal exógeno com analago de GnRH foi aplicado ... / Abstract: Brazil is the country with the greatest diversity of parrots in the world , with to 72 recognized species , with 16 species in the " Red List of Endangered Brazilian Wild Animals " . The blue-fronted amazon parrot ( Amazona aestiva ) stands out for its popularity as a pet , being collected from the wild in large numbers to attend the illegal market for wildlife. His captive breeding can become a tool for the conservation of populations in nature , but this requires a creation based on scientific knowledge and advanced breeding techniques . This thesis aimed to present the annual endocrine profile of sex steroids of Amazona aestiva and a test of hormonal stimulation by applying GnRH analogue of the slow release. It was used 10 couples and 4 adult males of Amazona aestiva kept in suspended cages, properties of the commercial breeder "Criadouro da Brisa", located in Jaboticabal / SP. The droppings were collected at least once a week between June 2011 and July 2012 for the understanding of endocrine processes of the reproduction in this specie and between August 2012 and December 2012 for testing hormonal stimulation . The monitoring of gonadal activity was noninvasively by measuring androgen metabolites in droppings of males and females of droppings progestogens. Fresh droppings samples were collected , always in between 14h to 17h , and kept frozen until processing . The samples were dried at 57oC, crushed and hormones were extracted using 80% methanol . The hormone dosage was performed at the Laboratory of Endocrinology, NUPECCE ( Center for Research and Conservation of Deer ) using enzyme immunoassay with antibody to androgens and progestins . In exogenous hormone stimulation test with GnRH was applied analago buserelin slow release in 5 couples and 5 couples were used to control the following excreta collection , processing and hormonal dosage previously described . The results of the annual listing of androgens in males ... / Doutor

Mutações inativadoras do receptor de GnRH (GNRHR) são a causa genética mais frequente de hipogonadismo hipogonadotrófico isolado (HHI) normósmico. Os genes envolvidos da patogênese do HHI, incluindo o GNRHR, estão associados a um amplo espectro fenotípico, variando de HHI parcial a completo. O atraso constitucional do crescimento e desenvovimento (ACCD) poderia constituir uma variante fenotípica leve do HHI. Neste estudo avaliamos a frequência de mutações no gene GNRHR em pacientes com HHI normósmico e ACCD, bem como correlacionamos o genótipo/fenótipo nesses pacientes. Além disso, avaliamos o efeito fundador de uma mutação do GNRHR (p.R139H) frequente na população brasileira com HHI normósmico. Para esse estudo, selecionamos 116 pacientes com HHI normósmico e 51 com ACCD. Um grupo de 130 indivíduos com desenvolvimento puberal normal foi utilizado como controle. A região codificadora do gene GNRHR foi amplificada por PCR e sequenciada. Análises in silico e in vitro foram realizadas nas duas novas variantes (p.V134G e p.Y283H). Três marcadores de microssatélites (D4S409, D4S2387, D4S3018) foram amplificados e analisados nos pacientes portadores da mutação p.R139H, familiares e controles. No grupo de HHI normósmico, nove mutações (p.N10K,p.Q11K, p.Q106R, p.R139H, p.C200Y, p.R262Q, p.Y284C, p.Y283H, p.V134G) foram identificadas em onze pacientes (9,5%). Entre as mutações identificadas no GNRHR, duas foram descritas pela primeira vez no estudo atual: p.Y283H e p.V134G, cuja análise in vitro demonstrou inativação completa do receptor. Em geral, uma boa correlação genótipo-fenótipo foi observada. Pacientes portadores de mutações inativadoras apresentavam HHI completo e mutações com perda parcial de função causavam HHI parcial, incluindo dois pacientes que evoluíram com reversão do hipogonadismo após reposição androgênica. Por outro lado, não houve diferença fenotípica entre os casos com e sem mutação do GNRHR. Análise de ancestralidade genética da mutação p.R139H demonstrou que todos os casos brasileiros apresentaram o mesmo haplótipo, sugerindo que a mutação p.R139H possui um ancestral comum na população brasileira. Por outro lado o caso familial proveniente da Polônia apresentou apenas um marcador em comum com as famílias brasileiras e estudos mais abrangentes seriam necessários para determinar a origem da mutação p.R139H em indivíduos não Brasileiros. Na casuística de ACCD apenas a mutação p.Q106R foi identificada no gene GNRHR em heterozigose em um paciente. Em conclusão, o GNRHR foi o gene mais comumente afetado, apresentando uma boa correlação genótipo-fenótipo, e deve ser o primeiro candidato para análise genética em HHI normósmico. Os resultados sugerem que a mutação p.R139H possui um ancestral comum na população brasileira. Mutações no GNRHR parecem não estar envolvidas na patogênese do ACCD / GnRH receptor (GNRHR) inactivating mutations are the most common genetic cause of normosmic IHH. The genes involved in the IHH, including GNRHR, have been associated with a large phenotypic spectrum, varying from partial to complete IHH. Constitutional delay of growth and puberty (CDGP) might represent a mild phenotypic variant of IHH. In this study we investigated novel variants and characterized the frequency and phenotype-genotype correlation of GNRHR mutations in normosmic IHH and CDGP patients. Additionally, we determined de cause of the recurrence of GNRHR p.R139H mutation in patients with normosmic IHH. We studied 116 patients with normosmic IHH and 51 with CDGP. The control group was composed by 130 adults with normal pubertal development. The coding region of GNRHR was amplified and automatically sequenced. The two novel variants identified (p.Y283H, p.V134G) were submitted to in silico and in vitro analysis. Three microsatellite markers (D4S409, D4S2387, D4S3018) were amplified by PCR and analyzed in the patients with the p.R139H mutation. In the CDGP group, the previously described mutation p.Q106R was identified in the heterozygous state in one boy. The p.Q106R mutation has been identified in heterozygous state in individuals with normal pubertal development and does not appear be involved on the CDGP phenotype in this patient. In the normosmic IHH group, nine variants were identified (p.N10K, p.Q11K, p.Q106R, p.R139H, p.C200Y, p.R262Q, p.Y284C, p.Y283H, p.V134G) in eleven patients (9.5%). In vitro analysis of the novel variants p.Y283H and the p.V134G demonstrated that both of them cause complete loss of function of the receptor. The founder effect study revealed that all the p.R139H affected Brazilian patients presented the same haplotype, suggesting that the this mutation has a common ancestor in the Brazilian population. Nevertheless the affected Polish family presented a different haplotype, with only one marker in common with the Brazilian families and further studies would be necessary to determine the origin of the p.R139H mutation in the European population. In conclusion this study demonstrated that GNRHR was the most commonly affected gene in normosmic IHH, with a good genotype-phenotype correlation, and should be the first candidate gene for genetic screening in this condition. The results of the founder effect study suggested that the p.R139H mutation has a common ancestor in the Brazilian population. Finally, mutations in the GNRHR do not appear to be involved in the pathogenesis of CDGP

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Puberdade precoce central em meninas à definida como desenvolvimento puberal causado pela ativaÃÃo do eixo hipotÃlamo-hipÃfise-gonadal antes de 8 anos de idade. Nestas condiÃÃes, a estimulaÃÃo das gonadotrofinas produz aumento dos ovÃrios e a secreÃÃo de estrogÃnio resulta em aumento uterino. O exame de ultra-som pÃlvico prova ser um mÃtodo preciso e nÃo invasivo na investigaÃÃo da genitÃlia interna de pacientes do sexo feminino. Ultra-sonografia pÃlvica foi sistematicamente realizada em 18 meninas com diagnÃstico de puberdade precoce central idiopÃtica para avaliar o impacto do tratamento com anÃlogo de GnRH na genitÃlia interna feminina. Antes e, em mÃdia, 3 meses apÃs o inÃcio do tratamento, foram avaliados os volumes uterino e ovarianos, o diÃmetro longitudinal do Ãtero, eco endometrial e grau de maturidade de Tanner. Os nossos dados demonstraram que o Ãtero e os ovÃrios estÃo aumentados na Ãpoca do diagnÃstico. ApÃs, aproximadamente 3 meses de terapia, ambos os volumes, uterino e ovarianos, reduziram seus valores, o comprimento do Ãtero diminuiu e houve uma regressÃo quanto ao estÃgio puberal de Tunner. Quanto ao eco endometrial nÃo houve mudanÃa significativa. Os nossos resultados confirmam a ecografia pÃlvica como uma ferramenta confiÃvel para investigaÃÃo da genitÃlia interna em meninas com puberdade precoce e como valioso mÃtodo para avaliaÃÃo da eficÃcia do tratamento com anÃlogo de GnRH. / Central precociuos puberty in girls is defined as pubertal development caused by activation of the hypothalamic-pituitary-gonadal axis before 8 years old. In this condition, gonadotropin stimulation produces ovarian enlargement and estrogen secretion results in uterine enlargement. Pelvic ultrasound has proven to be an accurate and noninvasive technique for investigation of internal genitalia in female patients. Pelvic ultrasonography was systematically perfomed on 18 girls with idiopathic central precociuos puberty to investigate the impact of treatment with gonadotropin-releasing hormone analogues on female internal genitalia. Before and after three months of treatment were evaluated ovarian and uterine volumes, uterine lenght, endometrial stripe and Tanner staging. Our data demonstrated that ovaries and uterus are enlarged at the time of diagnosis. Later, average 3 months of treatment, both ovarian and uterine volumes decreased, the uterine lenght decreased and the Tanner staging regressed. The endometrial echogenicity did not showed changes. Ours results confirmed pelvic ultrasonography as a reliable tool for investigation of internal genitalia in girls with precociuos puberty and as a valid method for evaluation of the efficacy of treatment with gonadotropin-releasing hormone analogues.

The mechanisms causing luteolysis of the primate corpus luteum are unknown. There is an increase in expression of liver x receptor (LXR) target genes and reduced low density lipoprotein receptor (LDLR) during spontaneous luteolysis in primates. The LXRs belong to the nuclear receptor superfamily and increase cholesterol efflux by inducing transcription of their target genes. Uptake of cholesterol into primate luteal cells occurs primarily via LDL, and LDLR transcription is regulated by sterol regulatory element binding transcription factor 2 (SREBF2). Luteinizing hormone (LH) and human chorionic gonadotropin (hCG) maintain luteal function by binding to the LH/CG receptor (LHCGR), which stimulates progesterone (P4) synthesis via protein kinase A (PKA). It has also been previously reported that there is an increase in 27-hydroxycholesterol (27OH) concentrations during spontaneous luteolysis in primates. Pregnenolone and P4 inhibit the enzyme activity of CYP27A1 (cytochrome p450, family 27, subfamily A, polypeptide 1), which converts cholesterol into 27OH, an oxysterol that is a natural LXR agonist and SREBF2 inhibitor. Therefore, the overall hypothesis is that LXR-induced cholesterol efflux and reduced LDL uptake via inhibition of SREBF2 activity mediate luteolysis of the human CL. The objective of study 1 is to determine the effects of LXR activation and SREBF2 inhibition on P4 production, cholesterol metabolism and gene expression; and how hCG signaling via PKA regulates these effects in human luteinized granulosa cells. Basal and hCG-stimulated P4 secretion were significantly decreased by the combined actions of the LXR agonist T0901317 (T09) and the SREBF2 inhibitor fatostatin, which was associated with alterations in cholesterol metabolism leading to reduced intracellular cholesterol storage. Expression of LXR target genes in the presence of T09 was significantly reduced by hCG, while hCG significantly increased LDLR expression. These effects of hCG were reversed by a specific PKA inhibitor. Chronic hCG exposure had similar effects on LXR target gene and LDLR expression without an exogenous LXR agonist. The objective of study 2 is to determine the effects of 27OH on P4 production and cholesterol metabolism; and to determine if inhibiting the conversion of cholesterol into pregnenolone increases LXR and decreases SREBF2 target gene expression via CYP27A1 in human luteinized granulosa cells. During luteolysis in primates and sheep, CYP27A1 expression significantly increased. 27OH significantly decreased hCG-stimulated P4 secretion and enhanced cholesterol efflux. Aminoglutethimide, which inhibits the conversion of cholesterol to pregnenolone, significantly increased ABCA1 and decreased LDLR. Knock-down of CYP27A1 resulted in a significant increase in P4 secretion, but did not prevent aminoglutethimide-induced effects on ABCA1 and LDLR. Knock-down of steroidogenic acute regulatory protein (STAR), which controls cholesterol transport into the mitochondria where CYP27A1 resides, significantly decreased LDLR transcription. Collectively, the data from study 1 support the hypothesis that LXR-induced cholesterol efflux and reduced LDL uptake via inhibition of SREBF2 activity mediates luteolysis in primates, which is reversed by hCG. Data from study 2 indicates that 27OH produced via CYP27A1 may contribute to reductions in P4 synthesis during luteolysis, partially by serving as a dual LXR agonist and SREBF2 inhibitor, although other oxysterols are also likely involved.