Made available in DSpace on 2015-03-26T13:46:51Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1801039 bytes, checksum: 20f5b40d56b71da169bd9632bf56a82a (MD5) Previous issue date: 2010-02-22 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This experiment has been developed in order to verify the thyroxine effect in the presence or absence of follicle stimulating hormone (FSH) on survival and growth of sheep preantral follicles. Fragments of ovarian tissue were grown for 1 or 7 days in a situation with a minimum essential (α-MEM +) alone or containing thyroxine (10, 20, 50 µg/mL) in the presence or absence of rFSH (50 ng/mL). The ovarian tissue non-grown (fresh control) and grown in different treatments were processed for analysis using the classical histology technique. When the days of culture were compared to the non-cultivated control, on the first day was found that the treatment with α-MEM+, FSH, T20 and T50 showed follicular survival percentages similar to control. When the treatments have been compared between each other within the growing season was identified that only on the 7th day, the treatment containing T50 presents a percentage of normal follicles significantly superior to the treatment with T10F. Related to the follicular diameter, the follicle in culture has not grown, since all treatments have had a similar behavior when controlling non-grown and α- MEM+, except the T10 treatment. When comparing the treatments within each growing season, it has been observed that on the first day, treatments T50, T10F and T50F have showed a follicular diameter greater when compared to T10 treatment. Similar to what happenedto follicular growth, oocitário growth has not grown either. For oocitário diameter, on the first day, there was a reduction for T10 and T20F treatments when compared to non-grown. On the 7th day of grown, FSH, T10F and T50F treatments have reduced oocitário diameter, with a progression of culture from the first day to the 7th one and even when compared to control non-grown and α-MEM+. It was concluded that high T4 concentrations (50 g / ml) have provided promising about the survival and follicular development in vitro. The association of T4 with FSH, have not presented positive results in the survival and follicular development in vitro. Although it is known the thyroxine action on ovarian physiology, there is a need to verify its importance for the in vitro development of preantral sheep follicles. / O presente experimento foi desenvolvido a fim de se verificar o efeito da tiroxina na presença ou ausência do hormônio folículo estimulante (FSH) sobre a sobrevivência e o crescimento de folículos pré-antrais de ovinos. Fragmentos de tecido ovariano foram cultivados por 1 e 7 dias em meio essencial mínimo (α-MEM+) suplementado ou não com diferentes concentrações de tiroxina (10, 20, 50 µg/mL) na presença ou ausência de rFSH (50 ng/mL). O tecido ovariano não-cultivado (controle fresco) e os fragmentos cultivados no dia 1 e 7 nos diferentes tratamentos foram processados e analisados utilizando a técnica de histologia clássica. Quando os dias de cultivo foram comparados ao controle não-cultivado, somente no dia 1 foi verificado que os tratamentos contendo α- MEM+, FSH, T20 e T50 mostraram percentuais de sobrevivência folicular semelhantes ao controle. Quando os tratamentos foram comparados entre si dentro de cada período de cultivo, foi observado que apenas no dia 7, o tratamento contendo T50 apresentou um percentual de folículos normais superior ao tratamento T10F. Com relação ao diâmetro folicular, não houve crescimento dos folículos em cultivo, uma vez que todos os tratamentos comportaram-se de maneira semelhante ao controle não-cultivado e ao α- MEM+, exceto o tratamento T10. Ao se comparar os tratamentos, dentro de cada período de cultivo, foi observado que no dia 1 os tratamentos T50, T10F e T50F apresentaram diâmetro folicular superior quando comparados ao tratamento T10. Semelhante ao crescimento folicular também não houve crescimento oocitário. Para o diâmetro oocitário, no dia 1, foi verificada uma redução para os tratamentos T10 e T20F quando comparados ao não cultivado. Já no dia 7 de cultivo os tratamentos FSH, T10F e T50F reduziram o diâmetro oocitário, com a progressão do cultivo do dia 1 para o dia 7 e ainda quando comparados ao controle não-cultivado e ao α-MEM+. Concluiu-se que altas concentrações de T4 (50 μg/ml) proporcionaram resultados promissores no que diz respeito à sobrevivência e desenvolvimento folicular in vitro. Quanto a associação da T4 com o FSH não demonstrou resultados positivos na sobrevivência e no desenvolvimento folicular in vitro. Embora seja conhecida a atuação da tiroxina na fisiologia ovariana são necessárias mais pesquisas que verifiquem sua importância para o desenvolvimento in vitro de folículos pré-antrais ovinos.

Background: There is sound evidence that the hypothalamic-pituitary-thyroid axis plays a role in mood regulation. Alterations in this axis, particularly low triiodothyronine syndrome, are a common neuroendocrine adaptation to semi-starvation in patients with anorexia nervosa (AN), who also frequently suffer from co-existing depressive symptoms. We therefore aimed to investigate the associations between pituitary-thyroid function and psychopathology, in particular depressive symptoms, at different stages of AN using a combined cross-sectional and longitudinal study design. Methods: Pituitary-thyroid status (FT3, free triiodothyronine; FT4, free thyroxine; conversion ratio FT3/FT4; TSH, thyroid-stimulating hormone) was assessed in 77 young acutely underweight females with AN (acAN) and in 55 long-term weight-recovered individuals with former AN (recAN) in a cross-sectional comparison to 122 healthy controls (HC). Further, pituitary-thyroid status of 48 acAN was reassessed after short-term weight-restoration. We performed correlation analyses of pituitary-thyroid parameters with self-reported measures of psychopathology. Results: AcAN showed significantly lower FT3, FT4, FT3/FT4 ratio, and TSH levels compared to HC. Pituitary-thyroid alterations were partly reversed after short-term weight-restoration. RecAN still had lower FT3 concentrations than HC. Lower FT3 concentrations and FT3/FT4 ratios were associated with more severe depressive symptoms in acAN, occurring prominently in cases of manifest low triiodothyronine syndrome. Longitudinally increasing FT3/FT4 ratios (change scores) were inversely correlated with depressive and general psychiatric symptoms after short-term weight-restoration. Conclusions: Our results suggest a potential modulation of the severity of depressive symptoms by temporarily decreased FT3 concentrations and inhibited thyroid hormone conversion (FT3/FT4 ratios) in acutely underweight AN. Associations between conversion ratios FT3/FT4 and psychopathology seem to persist across short-term weight-restoration. The findings of our study might have relevant clinical implications, ranging from thyroid monitoring to experimental low-dose thyroid hormone supplementation in certain patients with AN showing severe psychiatric impairment and overt thyroid hormone alterations.

Thyronamine (TAM) sind eine neue Molekülklasse, die endokrinologische und metabolische Prozesse miteinander vereinen. Der biologisch aktive Metabolit 3-Iod-L-Thyronamin (3-T1AM) wird durch eine kombinierte Deiodierung und Decarboxylierung von Schilddrüsenhormonen (TH) gebildet. Existierende Methoden zum Nachweis und zur Quantifizierung von 3-T1AM im menschlichen Serum sind immer noch umstritten. Auch die an der Biosynthese vermutlich beteiligte TH-Decarboxylase konnte noch nicht identifiziert werden. Für die Identifizierung und Quantifizierung von TH und TAM Profilen wurde die Flüssigchromatographie-Tandem-Massenspektrometrie (LC-MS/MS) verwendet. In der bisherigen präanalytischen Aufarbeitung liefern weder Flüssig-Flüssig- noch Festphasenextraktionen reproduzierbare Ergebnisse des 3-T1AM-Gehalts im Serum. Mit der Entwicklung eines spezifischen Extraktionsverfahrens und nachfolgender Detektion mittels LC-MS/MS gelang der gleichzeitige Nachweis der häufigsten TH im humanen Serum. Parallel dazu wurden monoklonale Antikörper gegen 3-T1AM entwickelt, auf deren Basis ein quantitativer 3-T1AM Chemilumineszenz-Immunoassay entstand. Ergebnisse aus klinischen Kollektiven zeigen, dass 3-T1AM im Serum im nM Konzentrationsbereich vorkommt und dass 3-T1AM bei Patienten außerhalb der Schilddrüse produziert wird. Viele Forscher gehen davon aus, dass die aromatische L-Aminosäure Decarboxylase (AADC) die Synthese von TAM über Decarboxylierung von TH katalysiert. Diese Hypothese wurde durch Inkubation von rekombinanter humaner AADC mit TH getestet. In keinem der Experimente konnte AADC die Decarboxylierung von TH katalysieren. Zusammenfassend ist die Bestimmung von 3-T1AM im Serum mittels LC-MS/MS aufgrund der nicht reproduzierbaren präanalytischen Probenaufbereitung problematisch. In dieser Arbeit wird der erste MAb-basierte 3-T1AM assay vorgestellt, der 3-T1AM zuverlässig in humanem Serum quantifiziert. Die AADC ist wahrscheinlich nicht an der Biosynthese von TAM beteiligt. / Thyronamines (TAM) are a new class of molecules linking endocrinology and metabolism. Combined deiodination and decarboxylation of thyroid hormones (TH) generates a biologically active ‘cooling’ metabolite, 3-iodo-L-thyronamine (3-T1AM).. It remains controversial, which methods are able or not to reliably detect 3-T1AM in human serum, and the presumed TH decarboxylase is still elusive. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for the simultane-ous identification and quantification of TH and TAM profiles in biological samples. Several preanalytical methods were tested for complete extraction of 3-T1AM in human serum. Thus far, neither liquid-liquid nor solid-phase extraction methods allowed reproducible extraction of 3-T1AM from human serum samples in the preanalytical sample workup. Nevertheless, a rapid and sensitive extraction procedure was developed for detection of the major TH by LC-MS/MS in a single human serum sample. In parallel, monoclonal antibodies (MAb) targeting 3-T1AM were developed and characterized, and a highly specific quantitative 3-T1AM MAb-based chemiluminescence immunoassay was developed. Studies in clinical cohorts provide evidence that 3-T1AM is present in human serum in the nM concentration range and that 3-T1AM is produced extrathyroidally. Many researchers have reasoned that the aromatic L-amino acid decarboxylase (AADC) mediates TAM synthesis via decarboxylation of TH. This hypothesis was tested by incubating recombinant human AADC with several TH. In all tested conditions, AADC failed to catalyze the decarboxylation of TH. These in vitro observations are supported by the finding that 3-T1AM is also present in plasma samples of patients with AADC deficiency. In summary, 3-T1AM detection in serum using LC-MS/MS encounters preanalytical problems. The first MAb-based 3-T1AM CLIA is presented, which reliably quantifies 3-T1AM in human serum. AADC is likely not involved in TAM biosynthesis.