Endocrine and regenerative cells in the midgut of Chagas' disease vector Triatoma vitticeps during different starvation periods.

Abstract

The midgut of an insect has three main cell types, viz., digestive, endocrine and regenerative cells, and a relationship between cell morphology and blood meal has been suggested. This study evaluated the occurrence of the regenerative and endocrine cells in different regions of the midgut of female and male Triatoma vitticeps during different periods after a blood meal. Adults of both sexes were dissected at 4, 72, 120, 168, 288, 360 and 600 hours after feeding and the midgut was pulled apart. The midgut was divided into the anterior, middle and posterior regions and the fragments were analyzed under a light microscope. The results showed the presence of endocrine cells of the open type and positive for FMRFamide as well as regenerative cell nests in the midgut of T. vitticeps. An association was observed between the starvation period and frequency of FMRFamide positive and regenerative cells in the midgut of T. vitticeps. Differences in the pattern of distribution of these cells between the males and females as well as in the different regions of the midgut were also discussed.