RESUMO

O hormônio antimulleriano é secretado pelas células da granulosa dos folículos que estão em desenvolvimento no ovário. Por meio da sua dosagem, é possível avaliar a reserva ovariana. A mulher tem seu número máximo de oócitos no perío- do fetal, mas, conforme o tempo passa, existe uma queda do número de células germinativas. Desse modo, para mulheres que têm o desejo de engravidar, a dosa- gem de hormônios e a avaliação da reserva ovariana podem ajudar no processo. O objetivo do estudo foi encontrar evidências na literatura que comprovem que o hormônio antimulleriano é o melhor marcador da reserva ovariana. Para isso, foi realizada uma revisão integrativa, classificada como qualitativa; a busca de da- dos foi realizada no PubMed, utilizando a seguinte palavra-chave: "hormônio anti- mulleriano (HAM)". Foram encontrados oito artigos que abordavam diretamente o tema, e há evidências que corroboram a hipótese de que o hormônio antimulleria- no é um bom marcador da reserva ovariana, sendo necessários mais estudos para determinar a sua superioridade.

The anti-mullerian hormone is secreted by the granulosa cells of follicles that are developing in the ovary. Though its dosage is possible to evaluate the ovarian re- serve. Women have their maximum number of oocytes in the fetal period, but there is a decrease in the number of germinative cells as time goes by. Thus, women that desire to get pregnant can have hormones dosed and the ovarian reserve evalua- ted to help them with this process. The objective of this study was to find evidence in the literature that proves that the anti-mullerian hormone is the best marker of ovarian reserve. For this purpose, an integrative review was conducted, using the key word: "anti-mullerian hormone (AMH)". Eight articles were found on the subject and there is evidence that proves the hypothesis of the anti-mullerian hormone as a good marker, however more studies are needed to determine its superiority.

Assuntos

RESUMO

Anti-Müllerian hormone (Amh) is a member of the transforming growth factor-ß (Tgf-ß) superfamily required in the regression of Müllerian ducts during gonadal sex differentiation of higher vertebrates. Teleost fish lack Müllerian ducts, but identified Amh orthologs have been shown to exert crucial functions during sex determination and differentiation of several species of teleosts. However, the function of Amh during gametogenesis in adult fish remains poorly investigated. Therefore, to expand present knowledge on the role of Amh in teleosts, the present study aimed to isolate and clone full-length amh cDNA in the common carp, Cyprinus carpio, and examine its expression levels throughout the male reproductive cycle and in response to different hormone treatments of testicular explants. Molecular cloning and characterization showed that the common carp Amh precursor amino acid sequence shared common features to other fish Amh precursors, including a conserved C-terminus (Tgf-ß domain) and a double proteolytic cleavage site (R-X-X-R-X-X-R) upstream to the Tgf-ß domain. Expression analysis showed amh dimorphic expression in the adult gonads with higher expression in the testes than ovaries. In testes, amh mRNA was detected in Sertoli cells contacting different types of germ cells, although the expression was greatest in Sertoli cells associated with type A undifferentiated spermatogonia. Expression analysis during the reproductive cycle showed that amh transcripts were down-regulated during the developing phase, which is characterized by an increased proliferation of type A undifferentiated spermatogonia and Sertoli cells and appearance of spermatocytes (meiosis) in the testes. Furthermore, ex vivo experiments showed that a 7 day exposure to Fsh or estrogens was required to decrease amh mRNA levels in common carp testicular explants. In summary, this study provided information on the molecular characterization and transcript abundance of amh in common carp adult testes. Altogether, these data will be useful for further investigations on sex determination and differentiation in this species, and also to improved strategies for improved carp aquaculture, such as inhibiting precocious maturation of males.

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RESUMO

The persistent Müllerian duct syndrome (PMDS) is a 46,XY disorder of sexual development characterized by the persistence of Müllerian duct derivatives, uterus and tubes, in otherwise normally masculinized males. The condition, transmitted as a recessive autosomal trait, is usually due to mutations in either the anti-Müllerian hormone (AMH) gene or its main receptor. Many variants of these genes have been described, all targeting the coding sequences. We report the first case of PMDS due to a regulatory mutation. The AMH promoter contains two binding sites for steroidogenic factor 1 (SF1), one at -102 and the other at -228. Our patient carries a single base deletion at -225, significantly decreasing its capacity for binding SF1, as measured by the electrophoresis mobility shift assay. Furthermore, by linking the AMH promoter to the luciferase gene, we show that the transactivation capacity of the promoter is significantly decreased by the mutation, in contrast to the disruption of the -102 binding site. To explain the difference in impact we hypothesize that SF1 could partially overcome the lack of binding to the -102 binding site by interacting with a GATA4 molecule linked to a nearby response element. We show that disruption of both the -102 SF1 and the -84 GATA response elements significantly decreases the transactivation capacity of the promoter. In conclusion, we suggest that the distance between mutated SF1 sites and potentially rescuing GATA binding motifs might play a role in the development of PMDS.

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