Morfologia, ultra-estrutura e imunohistoquímica do intestino médio de Triatoma vitticeps (Hemiptera, Triatominae)

• Ano de defesa: 2009
• Autor(a) principal: Rocha, Lamara Laguardia Valente
• Orientador(a): Serrão, José Eduardo
• Banca de defesa: Martins, Gustavo Ferreira , Lisboa, Luciane Cristina Oliveira , Alves, Stênio Nunes
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Biologia Celular e Estrutural
• Departamento: Análises quantitativas e moleculares do Genoma; Biologia das células e dos tecidos
• País: BR
• Palavras-chave em Português: Intestino médio; Morfofisiologia; Hemíptero; FMRFamide; Triatoma vitticeps
• Palavras-chave em Inglês: Midgut; Morphophysiology; Hemiptera; FMRFamide; Triatoma vitticeps
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: http://locus.ufv.br/handle/123456789/235

The insects success is due, among other factors, to adaptation for different food resources. Usually, the gut of the insect is divided into foregut, midgut and hindgut. The midgut is responsible for key roles in the digestive process, the enzymes synthesis, digestion and absorption. This study describes the morphology, ultrastructure and the occurrence of regenerative and endocrine cells in different midgut regions of the hematophagous Hemiptera, Triatoma vitticeps, at different periods after blood meal. Twenty- seven adult insects of both sexes were dissected at different periods after feeding and the midguts were analyzed in light and transmission electron microscopes. One hundred fields for each midgut region (anterior, middle and posterior) for each animal and at different times after meal were used for morphometric analysis and for counting the number of nuclei of digestive, endocrine and regenerative cells. The digestive cells are characterized by the presence of apical microvilli, basal plasma membrane invaginations and central nucleus. The perimicrovillar membrane was present in all specimens analyzed. The anterior portion of the midgut showed digestive cells with lipid droplets, glycogen granules, developed basal labyrinth associated with mitochondria suggesting its role in processes of storage, fluid flux and ions exchange. The cells of middle and posterior regions of the midgut are rich in rough endoplasmic reticulum, lysosomes, vesicles and granules with different electron-densities. Moreover, cells of the posterior portion of the midgut are rich in electron-dense granules that are similar to hemozoyn and mitochondria located at the base of microvilli suggesting its participation in blood digestion and absorption of nutrients. The similarity between the midgut of T. vitticeps with other Hemiptera suggests that they arose from a common ancestor and that the morphological features of the midgut is more related to monophyletic origin than the type of food. The results showed in the midgut occurrence of endocrine cells characterized as the type open and positive for FMRFamide. They also show a possible association between the food cycle, sex and region of the midgut with the frequency of endocrine, digestive and regenerative cells in this Triatominae.