title: Insight of EDX analysis and EFTEM: are spherocrystals located in Strombidae digestive gland implied in detoxification of trace metals?
abstract: Digestive tubules of Strombidae are composed by three cell types: digestive cells, vacuolated cells, and crypt cells. The last one is characterized by the presence of intracellular granules identified as spherocrystals. Such structures are known to occur in basophilic cells of gastropod digestive gland, where they are supposed to be involved in the regulation of some minerals and in detoxification. In this study, energy-dispersive X-ray analysis (EDX) and energy filtered transmission electron microscopy (EFTEM) were used to determine the elemental content of spherocrystals in two Strombidae, Strombus gigas and Strombus pugilis. In freshly collected individuals of both species, the following elements were detected: Ca, Fe, Mg, P, and Zn. Aluminum and Mn were also detected in S. gigas. Their presence in spherocrystals indicates that, in Strombidae, spherocrystals are involved in the regulation of minerals and essential trace metals. In order to answer the question "are spherocrystals involved in nonessential trace metals scavenging?," artificial cadmium and lead exposure by both waterborne and dietary pathways was applied to S. pugilis. No evidence of cadmium (Cd(NO(3))(2)) or lead (Pb(NO(3))(2)) provided by food was found in spherocrystals. Cadmium provided in water (Cd(NO(3))(2) and CdCl(2)) causes structural modifications of the digestive gland; however, this element was not trapped in spherocrystals. These results suggest that spherocrystals are not involved in detoxification of such nonessential trace metals.
authors.affiliation: UMR 7138 SAE, Equipe Biologie de la mangrove, Université des Antilles et de la Guyane, U.F.R des Sciences Exactes et Naturelles, Département de Biologie, B.P. 592. 97159 Pointe-à-Pitre Cedex, Guadeloupe, France. jmvollan@univ-ag.fr
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Volland
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Lechaire
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Frebourg
authors.forename: Dalila Aldana
authors.initials: DA
authors.lastname: Aranda
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Ramdine
authors.forename: Olivier
authors.initials: O
authors.lastname: Gros
mesh_terms: D000818:Animals; D019187:Cadmium Compounds / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000737:chemistry / Q000166:cytology / Q000502:physiology / Q000648:ultrastructure; D049851:Gastropoda / Q000737:chemistry / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D008658:Inactivation, Metabolic; D008670:Metals / Q000032:analysis / Q000493:pharmacokinetics*; D046032:Microscopy, Energy-Filtering Transmission Electron / Q000379:methods*; D009566:Nitrates / Q000378:metabolism; D010758:Phosphorus; D013052:Spectrometry, X-Ray Emission / Q000379:methods*
chemical_list: D019187:Cadmium Compounds; D008670:Metals; D009566:Nitrates; D010758:Phosphorus; C035196:cadmium nitrate