Pigmentação testicular em Physalaemus nattereri (Steindachner) (Amphibia, Anura) com observações anatômicas sobre o sistema pigmentar extracutâneo
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Data
2005-06-01
Autores
Oliveira, Classius de [UNESP]
Zieri, Rodrigo [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zoologia
Resumo
O presente estudo foi realizado com o intuito de relatar a ocorrência e morfologia de células pigmentares viscerais constituintes do sistema pigmentar extracutâneo em Physalaemus nattereri (Steindachner, 1863) (Leptodactylidae). Foram utilizados dez exemplares machos para a análise macroscópica e obtenção de fragmentos testiculares incluídos em resina e corados com H/E. Os anuros, dentre outros animais exotérmicos, possuem células especiais, os melanócitos, que se caracteriza por intensa pigmentação e sintetiza melanina, além de melanomacrófagos, que se caracteriza por atividade fagocítica e muitas vezes apresentam intensa pigmentação. A nomenclatura destas células não é consensual e, por isso, várias denominações são apresentadas, principalmente nos seguintes órgãos: fígado (como sinônimo de células de Kupffer), rins, baço e menos freqüentemente em outras localizações, com os termos - células pigmentares, células pigmentares extracutâneas, macrófagos pigmentados, melanomacrófagos, melanófagos, melanóforos e melanócitos. Para os anuros os estudos são recentes e relatam células pigmentares em poucas espécies. em Physalaemus nattereri e alguns anuros, os pigmentos melânicos são encontrados, além da cútis, em outros órgãos constituindo um sistema pigmentar extracutâneo, com diferentes ocorrências, tipos e quantidade em distintas espécies. Associados ao aparelho reprodutor de P. nattereri, os melanócitos foram observados nas gônadas, na albugínea e no interstício, especialmente associado com vasos sangüíneos. A notória presença de numerosas células com pigmento distribuídas no testículo confere uma coloração que varia do preto mesclado com branco ao preto intenso. Trata-se de uma rara peculiaridade e não há informações sobre seu significado funcional ou valor biológico.
The testes in the anurans are paired ovoid organs constituted by seminiferous structures surrounded by the fibrous connective tissue, commonly unprovided of pigments. This study tried to analyze the morphological characteristics of rare and conspicuous pigment-containing cells and their relationship with other structures. The pigment cells are variously and indistinctly also termed Kuppfer cells in the liver, pigment cells, extracutaneous pigment cells, pigmented macrophages, melanomacrophages, melanophage, melanophores and melanocytes in the liver, spleen and kidney and other visceral structures of exothermic vertebrates. Ten male samples of Physalaemus nattereri (Steindachner, 1863) (Leptodactylidae) were used. After macroscopic analyses, the testicular fragments were submitted to the histological routine, fixed with karnovisky, embedded Historesin and coloration with Haematoxylin/Eosin. A rare peculiarity was the presence of numerous pigment-containing cells (melanocytes) randomly distributed in the albuginea tunic and testicular interstitium, giving the testes a dark brown coloration. This unusual characteristic has been rarely described and in other lower vertebrates, the pigment cells can be found in different organs, constituting an extracutaneous pigmentary system of unknown function. Further, it was identified a conspicuous variation, as to presence and distribution pattern due to possible species-specific aspects. However, histologically there is no difference in the germ epithelium arrangement. Between the seminiferous locules, there is an inter-locular tissue composed by Leydig interstitial cells, fibroblasts, efferent ductules, melanocytes and blood vessels. This inter-locular tissue is relatively scarce, presenting melanocytes in all specimens analyzed intimate associated with blood vessels. They are irregular cells with numerous melanosomes and long cytoplasmic processes.
The testes in the anurans are paired ovoid organs constituted by seminiferous structures surrounded by the fibrous connective tissue, commonly unprovided of pigments. This study tried to analyze the morphological characteristics of rare and conspicuous pigment-containing cells and their relationship with other structures. The pigment cells are variously and indistinctly also termed Kuppfer cells in the liver, pigment cells, extracutaneous pigment cells, pigmented macrophages, melanomacrophages, melanophage, melanophores and melanocytes in the liver, spleen and kidney and other visceral structures of exothermic vertebrates. Ten male samples of Physalaemus nattereri (Steindachner, 1863) (Leptodactylidae) were used. After macroscopic analyses, the testicular fragments were submitted to the histological routine, fixed with karnovisky, embedded Historesin and coloration with Haematoxylin/Eosin. A rare peculiarity was the presence of numerous pigment-containing cells (melanocytes) randomly distributed in the albuginea tunic and testicular interstitium, giving the testes a dark brown coloration. This unusual characteristic has been rarely described and in other lower vertebrates, the pigment cells can be found in different organs, constituting an extracutaneous pigmentary system of unknown function. Further, it was identified a conspicuous variation, as to presence and distribution pattern due to possible species-specific aspects. However, histologically there is no difference in the germ epithelium arrangement. Between the seminiferous locules, there is an inter-locular tissue composed by Leydig interstitial cells, fibroblasts, efferent ductules, melanocytes and blood vessels. This inter-locular tissue is relatively scarce, presenting melanocytes in all specimens analyzed intimate associated with blood vessels. They are irregular cells with numerous melanosomes and long cytoplasmic processes.
Descrição
Palavras-chave
Leptodactylidae, melanina, melanócitos, pigmento, testículo, Leptodactylidae, Melanin, Melanocytes, pigment, testis
Como citar
Revista Brasileira de Zoologia. Sociedade Brasileira de Zoologia, v. 22, n. 2, p. 454-460, 2005.