Immunocytochemical localization of V-H super(+)-ATPase, Na super(+)/K super(+)-ATPase , and carbonic anhydrase in gill lamellae of adult freshwater euryhaline shrimp Macrobrachium acanthurus (Decapoda, Palaemonidae)

• Published in: Journal of experimental zoology. Part A, Ecological genetics and physiology Ecological genetics and physiology, 2015-08, Vol.323 (7), p.414-421
• Main Authors: Maraschi, Anieli Cristina, Freire, Carolina Arruda, Prodocimo, Viviane
• Format: Article
• Language: English
• Subjects: Decapoda; Macrobrachium acanthurus; Palaemonidae
• ISSN: 1932-5223; 1932-5231
• DOI: 10.1002/jez.1934

Physiological (organismal), biochemical, and molecular biological contributions to the knowledge of the osmoregulatory plasticity of palaemonid freshwater shrimps has provided a fairly complete model of transporter localization in their branchial epithelium. Direct immunological demonstration of the main enzymes in the gill epithelia of adult palaemonids is, however, still incipient. The diadromous freshwater shrimp Macrobrachium acanthurus was exposed to increased salinity (25ppt for 24hr), and its responses at the systemic level were evaluated through the assays of hemolymph osmolality and muscle hydration, and at cellular and subcellular levels through the activity and localization of the V-H super(+)-ATPase, the Na super(+)/K super(+)-ATPase , and the carbonic anhydrase. Results showed an increase in hemolymph osmolality (629 plus or minus 5.3mOsm/kg H sub(2)O) and a decrease in muscle hydration (73.8 plus or minus 0.5%), comparing values after 24hr in 25ppt with control shrimps in freshwater (respectively 409.5 plus or minus 15.8mOsm/kg H sub(2)O and 77.5 plus or minus 0.4%). V-H super(+)-ATPase was localized in pillar cells, whereas Na super(+)/K super(+)-ATPase in the septal cells. The main novelty of this study was that carbonic anhydrase was localized in the whole branchial tissue, in pillar and septal cells. Exposure to high salinity for 24hr led to no detectable changes in their localization or in vitro activity. Immunolocalization data corroborated the literature and current models of palaemonid gill ion transport. The absence of changes reinforces the need for the constant expression of these enzymes to account for the euryhalinity of these shrimps. J. Exp. Zool. 323A: 414-421, 2015.