ABSTRACT
We analysed the morphology and ultrastructure of the gill apparatus of the ornate wrasse, Thalassoma pavo, under normal conditions and after exposure to a sublethal concentration of sodium lauryl sulphate (3.5 mg/l, which is one-third of the 96LC99 value). To identify the biochemical mechanisms affected by this pollutant, we evaluated and compared the localisation of Na(+)/K(+) ATPase in normal and experimental conditions. Immunocytochemical analysis revealed that this enzyme was active in the chloride cells (CCs), which were distributed in clusters in the interlamellar region of the filament. Ultrastructural analysis revealed conspicuous alterations on the epithelium after 96 and 192 h of exposure to sodium lauryl sulphate: structural features of the surface cells were lost, the appearance of intercellular lacunae changed, and cellular degeneration occurred. Statistical analysis comparing the number and dimensions of CCs in normal conditions and after 96 h of exposure showed that the CC area decreased after exposure to the detergent.
Subject(s)
Gills/drug effects , Gills/enzymology , Perciformes/metabolism , Sodium Dodecyl Sulfate/toxicity , Sodium-Potassium-Exchanging ATPase/metabolism , Animals , Dose-Response Relationship, Drug , Epithelial Cells/drug effects , Gills/ultrastructure , Immunohistochemistry , Microscopy, Confocal , Water Pollutants, Chemical/toxicityABSTRACT
We analyzed the skin of Triturus italicus (Amphibia, Urodela) histologically during the larval, pre-metamorphic and adult phases in parallel with the immunohistochemical evaluation of the expression of two nitric oxide synthase (NOS) isoforms, i.e. the inducible NOS (iNOS) and the endothelial NOS (eNOS). Our results indicate that, during the larval and adult phases, substantial changes in the intensity and localization of both iNOS and eNOS are present. In contrast, the pre-metamorphic newts show a labelling pattern similar to that found in the skin of adult individuals. These data suggest an involvement of the NOS system in the larval epidermis during functional maturation phase starting at the climax and preceding structural rearrangements during metamorphosis, emphasizing the putative functional importance of differential isoform expression related to a distinct phase of the biological cycle.
