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- Para Além da Falta de Iodo: O Papel do Ambiente no HipotiroidismoPublication . Coelho, Nádia; Garcia, Patrícia; Rodrigues, ArmindoA tiroide é uma glândula do sistema endócrino em forma de borboleta situada na parte anterior do pescoço, logo à frente da traqueia (figura 1). Esta glândula encarrega-se de produzir as hormonas tetraiodotironina (tiroxina ou T4) e triiodotironina (T3). As hormonas da tiroide atuam sobre vários aspetos do metabolismo: questões como o desenvolvimento neuronal, ritmo cardíaco, ritmo respiratório, função muscular, função digestiva, manutenção dos ossos, etc., são todas controladas pela ação da T4 e da T3. Neste sentido, a perturbação do equilíbrio destas hormonas acarreta consequências para todo o organismo. A produção hormonal dá-se ao nível celular dos folículos tiroideus, os quais consistem numa camada epitelial de células cuboides disposta em forma de esfera, e em cujo interior se encontra o coloide – local onde é armazenada a proteína tiroglobulina. É a tiroglobulina que permite a síntese de T4 e T3 pelas células foliculares quando necessário.
- Histological evidence of hypothyroidism in mice chronically exposed to conventional farmingPublication . Coelho, Nádia; Camarinho, Ricardo; Garcia, Patrícia; Rodrigues, ArmindoWorldwide, disorders of the thyroid gland are a growing concern; such can be caused by exposure to contaminants, including agrochemicals used in conventional agriculture, which act as endocrine disruptors. The purpose of this study is to evaluate whether or not exposure to an environment with conventional agriculture leads to thyroid disruption. Mus musculus were used as bioindicator species, captured in two sites: a farm where conventional agriculture is practiced, and a place without agriculture. Thyroid histomorphometric and morphologic data were analyzed. The impacts of the agricultural environment over the thyroid were revealed, as indications of hypothyroidism were observed in exposed mice: the area and volume of epithelial cells were much lower. Alterations in thyroid histomorphology were also observed: lower follicular sphericity, irregularly delimited epithelium and increased exfoliation into the colloid. These results highlight the need for transition from current conventional agricultural systems towards organic systems.