title: [Composition, structure and mode of formation of mineral concretions in the midgut of the Cercopid (Homoptera)].
abstract: The granules which occur in the cells of a part of the midgut wall in Cercopid larvae and adults (Homoptera) have been studied by biochemical and cytochemical methods and by electron microscopy. The granules have a diameter up to about 2micro and contain calcium, magnesium, iron, carbonates, and phosphates. Protein and acid mucopolysaccharide have also been detected. A chromatographic study shows that uric acid and guanine are not present. The young concretions occur primarily in ergastoplasmic cisternae. They are first wholly electron-opaque, but their center becomes more and more clear. In very old spheres, only a thin shell of electron-opaque material remains. The spheres which have reached about 1micro in diameter are all associated with myelin figures. The granule-containing cells, which nearly occlude the lumen of the midgut in larvae, are eliminated in the very young adults, but the storage excretion still continue in adults.
mesh_terms: D000818:Animals; D002118:Calcium / Q000032:analysis; D002254:Carbonates / Q000032:analysis; D002845:Chromatography; D003594:Cytoplasmic Granules; D004721:Endoplasmic Reticulum; D006025:Glycosaminoglycans / Q000032:analysis; D006147:Guanine / Q000032:analysis; D006651:Histocytochemistry; D007313:Insecta / Q000166:cytology*; D007422:Intestines / Q000166:cytology*; D007501:Iron / Q000032:analysis; D008274:Magnesium / Q000032:analysis; D008854:Microscopy, Electron; D010710:Phosphates / Q000032:analysis; D014527:Uric Acid / Q000032:analysis
chemical_list: D002254:Carbonates; D006025:Glycosaminoglycans; D010710:Phosphates; D014527:Uric Acid; D006147:Guanine; D007501:Iron; D008274:Magnesium; D002118:Calcium
vernacular_title: Composition, structure, et mode de formation des concrétions minérales dans l'intestin moyen des Homopteres Cercopides.