Características morfológicas estruturais e ultraestruturais do epitélio palatino de guinea pig (Cavia porcellus - Linnaeus, 1758)
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Data
2019
Autores
Tomiate, André Neri [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A Cavia porcellus, popularmente conhecida como guinea pig, consiste em uma espécie de roedor domesticado amplamente difundido como modelo experimental e, como outros exemplares da Ordem Rodentia, caracteriza-se pela dentição especializada, incisivos longos, caninos ausentes e pelo prolongamento na cavidade oral entre os dentes incisivos e pré-molares ou molares, denominado de diastema. A cavidade oral consiste na primeira região do sistema digestório e é responsável pela triagem e processamento dos alimentos, além da secreção salivar para a formação inicial do bolo alimentar, e dentro da região, destacam-se a língua e epitélio do palato, que apresentam funcionalidade somatossensitiva, identificam a textura, temperatura e consistência dos alimentos. O epitélio palatino apresenta duas regiões principais, a primeira denominada de palato duro consiste no epitélio localizado acima do osso palatino, enquanto a região do palato mole carece de suporte ósseo. Na maior parte dos mamíferos, o palato duro é caracterizado pelo epitélio queratinizado, estratificado com a presença de longas papilas da lâmina própria projetadas no epitélio e o palato mole pode possuir o epitélio queratinizado ou paraqueratinizado, estratificado, com a presença de papilas associadas a botões gustativos ou papilas da lâmina própria invaginando na região do epitélio, além da presença de ductos de secreção salivar e glândulas ácinas. O epitélio palatino da guinea pig não apresenta descrição microscópica na literatura e sua caracterização possibilita a melhor compreensão da biologia e taxonomia, portanto o objetivo do presente trabalho foi descrever a morfologia estrutural e ultraestrutural do epitélio palatino da Cavia porcellus. Foram utilizados 12 epitélios palatinos de C. porcellus fêmeas provenientes do acervo do Laboratório de Morfologia e Atividade Física da Universidade Estadual Paulista - Campus de Rio Claro, SP. Para análise sob microscopia de luz (ML), os epitélios palatinos (n=4) foram corados em hematoxilinaeosina e Picrosírius red. Para descrição sob microscopia eletrônica de varredura as amostras (n=6) foram preparados para análise da superfície epitelial (n=3) e do tecido conjuntivo associado da lâmina própria (n=3), através da remoção do epitélio sob técnica de maceração. Para a análise sob microscopia eletrônica de transmissão foram utilizados epitélios palatinos (n=2) para descrever a ultraestrutura. O palato duro da C. porcellus caracteriza-se espesso e queratinizado e assim como em outros mamíferos, é composto por camadas córnea, granulosa, espinhosa e lâmina basal. Na superfície do epitélio palatino localizam-se papilas cônicas na porção rostral, papilas filiformes na região medial e no palato mole existem projeções epiteliais diminutas que envolvem ductos salivares. Após a técnica de maceração do epitélio foi possível verificar que a região rostral apresenta projeções da lâmina própria caracterizadas como processos espinhosos delgados e densos, que diminuem de tamanho e densidade em direção a região caudal do palato duro até apresentarem aspecto laminar na transição palato duro-mole. O palato mole possui poros de secreção angulados na direção da orofaringe associados a glândulas salivares. Em relação a literatura, as papilas filiformes centralizadas no palato duro estão situadas em mesmo local que as pregas palatinas de outros roedores e assim como em outros mamíferos, as camadas mais profundas do epitélio apresentam mecanorreceptores responsáveis pela somatossensação, na guinea pig foi encontrado um corpúsculo lamelar, sugerindo assim função análoga das rugas e papilas filiformes palatinas.
Cavia porcellus, popularly known as guinea pig, consists in a domesticated specie of rodent widespread as a experimental model and like other specimens of the Order Rodentia, it is characterized by specialized dentition, long incisors, missing canines and by the espace in oral cavity between incisors and pre-molars or molars, called diastema. The oral cavity consists in the first region of digestory system and is responsable for screening and process food, besides saliva secretion for the inicial formation of the bolus, in this region, contrats tougue and palatine epithelium, these structures has somatosensitive function, they identify food texture, temperature and consistency. The palatine epithelium has two main regions, the first called hard palate consistis in the epithelium localized above palatine bone, while the soft palate region lacks bone support. In most mammals, hard palate is characterized by keratinized epithelium stratified with the presence of long papillae of lamina propria projected into the epithelium and the soft palate may have stratified, keratinized or parakeratinized epithelium with the presence of taste bud associated or papillae of lamina propria itself invaginating in the epithelium region, in addition to the presence of salivary secretion ducts and acid glands. The guinea pig palatine epithelium doesn’t have microscopic description in the literature, so the objective of the present study was to describe the structural and ultrastructural morphology of the palatine epithelium of Cavia porcellus. The palatine epithelium of twelve female C. porcellus from the collection of Morphology and Physical activity Laboratory of Paulista Estate University – Campus of Rio Claro, SP. Under light microscopy analysis, palatine epithelium (n=4) were stained with hematoxylin-eosine solution and pircrosirius red. For description uneder scanning electron microscope samples (n=6) were prepared for analysis of ephitelial surface (n=3) and connective tissue core of lamina propria (n=3) by epithelial removal under maceration techinique. For analysis under transmission elecron microscope were used palatine epithelium (n=2) for ultrastructure description. Hard palate of C. porcellus is characterized thick and keratinized as in other mammals, it is composed by corneum, granulosum, spinosum and basale layer. On the surface of palatine epithelium are conical papillae in the rostral portion, filiform papillae in the medial region and on the soft palate there are epithelial projections involving salivary ducts. After the epithelial maceration techinique, it was possible to verify that the rostral region presents projections of the lamina propria characterized as thin and dense spinous processes, which decrease in size and density towards the caudal region of the hard palate until they appear laminar in the hard-soft palate transition. The soft palate has angled pores of secretion toward the oropharynx associated with salivary glands. In relation to the literature, the hard palate-centered filiform papillae are located in the same place as the palatine folds of other rodents and, as in other mammals, the deeper layers of the epithelium have mechanoreceptors responsible for somatosensation. In the guinea pig a corpuscle was found. lamellar, thus suggesting analogous function of the palatine filiform wrinkles and papillae.
Cavia porcellus, popularly known as guinea pig, consists in a domesticated specie of rodent widespread as a experimental model and like other specimens of the Order Rodentia, it is characterized by specialized dentition, long incisors, missing canines and by the espace in oral cavity between incisors and pre-molars or molars, called diastema. The oral cavity consists in the first region of digestory system and is responsable for screening and process food, besides saliva secretion for the inicial formation of the bolus, in this region, contrats tougue and palatine epithelium, these structures has somatosensitive function, they identify food texture, temperature and consistency. The palatine epithelium has two main regions, the first called hard palate consistis in the epithelium localized above palatine bone, while the soft palate region lacks bone support. In most mammals, hard palate is characterized by keratinized epithelium stratified with the presence of long papillae of lamina propria projected into the epithelium and the soft palate may have stratified, keratinized or parakeratinized epithelium with the presence of taste bud associated or papillae of lamina propria itself invaginating in the epithelium region, in addition to the presence of salivary secretion ducts and acid glands. The guinea pig palatine epithelium doesn’t have microscopic description in the literature, so the objective of the present study was to describe the structural and ultrastructural morphology of the palatine epithelium of Cavia porcellus. The palatine epithelium of twelve female C. porcellus from the collection of Morphology and Physical activity Laboratory of Paulista Estate University – Campus of Rio Claro, SP. Under light microscopy analysis, palatine epithelium (n=4) were stained with hematoxylin-eosine solution and pircrosirius red. For description uneder scanning electron microscope samples (n=6) were prepared for analysis of ephitelial surface (n=3) and connective tissue core of lamina propria (n=3) by epithelial removal under maceration techinique. For analysis under transmission elecron microscope were used palatine epithelium (n=2) for ultrastructure description. Hard palate of C. porcellus is characterized thick and keratinized as in other mammals, it is composed by corneum, granulosum, spinosum and basale layer. On the surface of palatine epithelium are conical papillae in the rostral portion, filiform papillae in the medial region and on the soft palate there are epithelial projections involving salivary ducts. After the epithelial maceration techinique, it was possible to verify that the rostral region presents projections of the lamina propria characterized as thin and dense spinous processes, which decrease in size and density towards the caudal region of the hard palate until they appear laminar in the hard-soft palate transition. The soft palate has angled pores of secretion toward the oropharynx associated with salivary glands. In relation to the literature, the hard palate-centered filiform papillae are located in the same place as the palatine folds of other rodents and, as in other mammals, the deeper layers of the epithelium have mechanoreceptors responsible for somatosensation. In the guinea pig a corpuscle was found. lamellar, thus suggesting analogous function of the palatine filiform wrinkles and papillae.
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Palavras-chave
Morfologia animal, Cavidade oral, Epitélio palatino, Palato, Cavia porcellus, Morfologia, Morphology, Oral cavity, Palate, Palatine epithelium