Efeitos da variação térmica no sistema pigmentar extracutâneo do anuro Eupemphix nattereri (Anura: Leiuperidae)
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Data
2010-06-02
Autores
Santos, Lia Raquel de Souza [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Os vertebrados ectotérmicos apresentam um desenvolvido sistema de células com pigmentos melânicos em seu citoplasma, localizadas em diversos órgãos e estruturas formando um sistema pigmentar extracutâneo. Esses tipos celulares são grandes e irregulares, com o citoplasma abundante e intensamente pigmentado e variam de um aspecto estrelado ao puntiforme. São encontrados também associados ao aparelho reprodutor de algumas espécies de anuros, conferindo uma tonalidade escura. Esta característica anatômica de coloração testicular faz parte da arquitetura somática do órgão e na literatura não há qualquer dado que aponte para uma inter-relação entre estes componentes. Células contendo pigmentos melânicos são encontradas também no fígado, onde apresentam atividade fagocítica, sendo denominadas melanomacrófagos ou células de Kupffer, e não eram incluídas na classificação de célula pigmentar, pois se pensava que os macrófagos presentes no fígado e baço apenas fagocitavam os melanossomos, e não os sintetizavam. Entretanto, análises sobre a função melanogênica das células pigmentares nesses órgãos em algumas espécies demonstraram que há melanogênese. Para os anfíbios anuros, os estudos relativos aos melanócitos viscerais e aos melanomacrófagos são recentes e se referem à poucas espécies. Alguns estudos demonstraram que alterações do sistema melanogênico pode estar relacionado ao aumento da pigmentação no fígado e a hemocaterese hepática. Há também, trabalhos que relatam modificações metabólicas e estruturais das células hepáticas durante o inverno, não sendo descritas funções para as células pigmentares presentes nos demais órgãos. Assim, neste trabalho objetivamos analisar a resposta das células...
Ectothermic vertebrates present a well-developed system composed of cells with melanin in its cytoplasm. These cells are distributed in several organs and tissues constituting an extracutaneous pigmentary system. These cells types are big and irregular, with shapes that vary from a star-shaped to a punctiform format. In addition, its cytoplasm is abundantly pigmented. In anuran amphibians this pigmented cells are also found associated to the reproductive system, what gives to the gonads a dark coloration. This coloration makes part of the somatic architecture of the organ, but there is no data in the literature that suggest a function for this pigmentation. Melanin-contemning cells are also found on the liver, where show phagocytic activity, being called melanomacrophages or Kupffer cells, and were not included in the classification of pigmentary cell, since it was thought that the macrophages in the liver and spleen only phagocyted the melanosomes, not synthesizing them. However, some analysis about the melanogenic function of these pigmentary cells in these organs show that melanogenesis indeed takes place. To anuran amphibians, the studies concerning to the viceral melanocytes and to the melanomacrophages are recent and refer to just a few species. Some studies show that changes in the melanogenic system can be related to the increase in the pigmentation on the liver and to the hepatic hemocateresis. Furthermore, some studies report modifications both metabolic and structural in hepatic cells during the winter, but not designating any function for the pigmented cells present in other organs. Our aim in this study was to analyze the response of the cells of the extracutaneous pigmentar system of the anuran Eupemphix nattereri to a varying thermal condition... (Complete abstract click electronic access below)
Ectothermic vertebrates present a well-developed system composed of cells with melanin in its cytoplasm. These cells are distributed in several organs and tissues constituting an extracutaneous pigmentary system. These cells types are big and irregular, with shapes that vary from a star-shaped to a punctiform format. In addition, its cytoplasm is abundantly pigmented. In anuran amphibians this pigmented cells are also found associated to the reproductive system, what gives to the gonads a dark coloration. This coloration makes part of the somatic architecture of the organ, but there is no data in the literature that suggest a function for this pigmentation. Melanin-contemning cells are also found on the liver, where show phagocytic activity, being called melanomacrophages or Kupffer cells, and were not included in the classification of pigmentary cell, since it was thought that the macrophages in the liver and spleen only phagocyted the melanosomes, not synthesizing them. However, some analysis about the melanogenic function of these pigmentary cells in these organs show that melanogenesis indeed takes place. To anuran amphibians, the studies concerning to the viceral melanocytes and to the melanomacrophages are recent and refer to just a few species. Some studies show that changes in the melanogenic system can be related to the increase in the pigmentation on the liver and to the hepatic hemocateresis. Furthermore, some studies report modifications both metabolic and structural in hepatic cells during the winter, but not designating any function for the pigmented cells present in other organs. Our aim in this study was to analyze the response of the cells of the extracutaneous pigmentar system of the anuran Eupemphix nattereri to a varying thermal condition... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Biologia animal, Anuro - Morfologia, Eupemphyx nattereri, Pigmentary system, Temperature, Liver, Testicle, Anuran
Como citar
SANTOS, Lia Raquel de Souza. Efeitos da variação térmica no sistema pigmentar extracutâneo do anuro Eupemphix nattereri (Anura: Leiuperidae). 2010. 126 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências, Letras e Ciências Exatas, 2010.