ABSTRACT
A new class of insecticide derived from fermentation of Sacharopolyspora spinosa - spinosad, has been indicated as being of low toxicity and a natural alternative to classical pesticides. In order to elucidate several aspects related to the morphophysiological changes induced by spinosad in Artibeus lituratus, the effects of a seven-day administration on plasma glucose, glycogen, protein and lipid concentrations were evaluated, and possible changes in liver cells were examined by histological analysis. Animals were fed with spinosyn-contaminated fruit through immersion in a solution. Data reporting on metabolism revealed a decrease in hind limb muscle lipid concentration in the treated group. Morphological analysis indicated a significant increase in liver cell diameter in treated animals compared to the control group. This study indicates that spinosyn, used at its recommended dose, does not affect general energy metabolism in A. lituratus but may affect some ultrastructural characteristics of liver cells.
Uma nova classe de inseticida derivado da fermentação de Sacharopolyspora spinosa - espinosade - tem sido indicada como uma alternativa natural de baixa toxicidade aos agrotóxicos clássicos. A fim de elucidar diversos aspectos relacionados às mudanças morfofisiológicas induzidas por espinosade Artibeus lituratus, os efeitos da administração durante sete dias sobre a glicose plasmática, proteína de glicogênio, e as concentrações de lipídios foram avaliados, assim como possíveis alterações nas células do fígado foram examinadas por análise histológica. Os animais foram alimentados com frutas contaminadas com espinosade por meio de imersão em uma solução. Os dados sobre o metabolismo revelaram um decréscimo na concentração de lipídios dos músculos das patas posteriores dos animais do grupo tratado. A análise morfológica indicou um aumento significativo no diâmetro das células do fígado dos animais tratados em relação ao controle. Este estudo indica que o espinosade, utilizado na dose recomendada, não afeta o metabolismo energético em geral de A. lituratus, mas pode afetar algumas características ultraestruturais das células hepáticas.
Subject(s)
Animals , Male , Chiroptera/metabolism , Energy Metabolism/drug effects , Insecticides/pharmacology , Liver/pathology , Macrolides/pharmacology , Blood Glucose/analysis , Chiroptera/classification , Drug Combinations , Glycogen/analysis , Lipids/analysis , Liver/drug effectsABSTRACT
In Hymenoptera, midgut changes begin in the last instar. At this stage, the larval epithelial digestive cells degenerate, leaving only the basal membrane and the regenerative cells which will develop into a new epithelium during the pupal stage and in the adult. Epithelium renewal is followed by changes in volume and shape of the midgut. Morphometric analysis of digestive cells and total midgut volume of Melipona quadrifasciata anthidioides (Lepeletier) were conducted to verify whether cell volume increase are sufficient to account for the total midgut volume increase that occurs during metamorphosis. An increase in midgut volume was verified in spite of the scarcity of cell proliferation found during metamorphosis. At the end of metamorphosis, the increase in cell volume was not sufficient to explain the increase in volume of the midgut, indicating that an increase in the number of digestive cells is apparently necessary. Nevertheless, the mechanism by which regenerative cells reconstitute the epithelium during metamorphosis remains unknown.