Daño ultraestructural del intestino medio abdominal de Lutzomyia ovallesi (Ortiz) (Diptera: Psychodidae) ocasionado por Leishmania (Leishmania) amazonensis

Abstract

A study was done in the middle intestine of Lutzomyia ovallesi infected with Leishmania (Leishmania) amzonensis. The females were examined seven days after infection by means of high resolution light microscopy and transmission electron microscopy. Two kinds of epithelial cells, digestive and secretory, were observed in the middle intestine of L. ovallesi, in both control insects and in those infected. Results showed changes in the cytoarchitecture of the intestine as a consequence of infection with L. (L.) amazonensis. There was a great increase in the diameter of the intestine, showing signs of cellular degeneration, such as partial or total loss of microvilli and the thickening of the basal layer of the whole portion of the intestine. Epithelial cells showed damage in vacuoles and mitochondria, and epithelial waste was observable in the intestine. Cellular damage in the middle intestine of L. ovallesi produced by infection with L. (L.) amazonensis is perhaps connected with lectin secretion and formation of gel, similar to that of a matrix, in the intestinal lumen. More studies are needed to clarify important aspects of the relationship between Leishmania and the vector.