title: Effects of ammonia stress in the Amazon river shrimp Macrobrachium amazonicum (Decapoda, Palaemonidae).
abstract: We evaluate the effects of total ammonia nitrogen-N (TAN) exposure for 72h on (Na(+),K(+))- and V(H(+))-ATPase activities and on their subunit expressions in gills of the diadromous freshwater shrimp Macrobrachium amazonicum. Specific (Na(+),K(+))- and V(H(+))-ATPase activities increased roughly 1.5- to 2-fold, respectively, after exposure to 2.0mmolL(-1) TAN. Quantitative RT-PCR analyses revealed a 2.5-fold increase in V(H(+))-ATPase B subunit mRNA expression while (Na(+),K(+))-ATPase α-subunit expression was unchanged. Immunohistochemical analyses of the gill lamellae located the (Na(+),K(+))-ATPase throughout the intralamellar septal cells, independently of TAN concentration, while the V(H(+))-ATPase was located in both the apical pillar cell flanges and pillar cell bodies. Systemic stress parameters like total hemocyte count decreased by 30% after exposure to 2.0mmolL(-1) TAN, accompanied by increased activities of the oxidative stress enzymes superoxide dismutase, glutathione reductase and glucose-6-phosphate dehydrogenase in the gills. The stress responses of M. amazonicum to elevated TAN include increases in gill (Na(+),K(+))- and V(H(+))-ATPase activities that are accompanied by changes in oxidative stress enzyme activities, immune system effects and an increase in gill V(H(+))-ATPase gene expression. These findings likely underpin physiological effects in a crustacean like M. amazonicum that exploits multiple ecosystems during its life cycle, as well as under culture conditions that may significantly impact shrimp production by the aquaculture industry.
authors.affiliation: Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto/USP, Brazil.
authors.forename: Marcelo R
authors.initials: MR
authors.lastname: Pinto
authors.affiliation: Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto/USP, Brazil.
authors.forename: Malson N
authors.initials: MN
authors.lastname: Lucena
authors.affiliation: Departamento de Biologia -Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto/USP, Brazil.
authors.forename: Rogério Oliveira
authors.initials: RO
authors.lastname: Faleiros
authors.affiliation: Universidade Estadual Paulista Júlio de Mesquita Filho - Campus de São José do Rio Preto, Brazil.
authors.forename: Eduardo Alves
authors.initials: EA
authors.lastname: Almeida
authors.affiliation: Departamento de Biologia -Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto/USP, Brazil.
authors.forename: John C
authors.initials: JC
authors.lastname: McNamara
authors.affiliation: Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto/USP, Brazil. Electronic address: fdaleone@ffclrp.usp.br.
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Leone
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000641:Ammonia / Q000633:toxicity*; D000818:Animals; D002452:Cell Count; D004781:Environmental Exposure / Q000032:analysis; D005880:Gills / Q000187:drug effects / Q000201:enzymology; D006434:Hemocytes / Q000166:cytology / Q000187:drug effects; D007700:Kinetics; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology; D010084:Oxidation-Reduction; D033541:Palaemonidae / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D045483:Rivers; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D025262:Vacuolar Proton-Translocating ATPases / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D012333:RNA, Messenger; D014874:Water Pollutants, Chemical; D000641:Ammonia; D000255:Adenosine Triphosphate; D025262:Vacuolar Proton-Translocating ATPases; D000254:Sodium-Potassium-Exchanging ATPase
keywords: (Na(+),; Ammonia exposure; Gene expression; Gill microsome; K(+))-ATPase; Macrobrachium amazonicum; Oxidative enzymes; V(H(+))-ATPase