title: Dynamics of murine B lymphocytes is modulated by in vivo treatment with steroid ouabain.
abstract: Ouabain (OUA) is a steroid hormone capable of inhibiting the protein Na+K+ATPase present in the plasma membrane of cells. Ouabain was initially extracted from the roots of African trees such as Acocanthera ouabaio and Strophantus gratus seeds and later described as an endogenous component found in higher mammals. The adrenal gland is the main site of synthesis of ouabain and it is released in stressful situations, conditions similar to those where there is secretion of corticosteroids. Immunological functions have been shown to be regulated by ouabain. In order to understand the effects of ouabain on B lymphocyte populations in different lymphoid organs, mice received intraperitoneal injections of ouabain for 3 consecutive days. Twenty-four hours after the last injection, cells were analyzed by flow cytometry. In the spleen, ouabain modulated especially follicular B cells, inducing a significant decrease in the percentage and absolute numbers of those cells. Ouabain also reduced the absolute number of marginal zone B lymphocytes. No difference in the percentage or absolute number of B lymphocytes in the spleen forty-eight hours after the last injection was observed. An increase in the number of B cells was seen in mesenteric lymph nodes and this retention appears to be directly related to increased expression of CXCR5 chemokine receptor and reduction of CD62L, which also explains the observed reduction of B cells in the spleen. Our results indicate that ouabain regulates the dynamics of B lymphocytes in peripheral organs but production of total IgM and IgG in the serum of animals treated in vivo with ouabain was not affected.
authors.affiliation: Departamento de Imunobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil; Programa de Pós Graduação em Patologia/UFF, Niterói, Brazil.
authors.forename: Joyle Moreira Carvalho
authors.initials: JM
authors.lastname: da Silva
authors.affiliation: Departamento de Imunobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.
authors.forename: Augusto
authors.initials: A
authors.lastname: das Neves Azevedo
authors.affiliation: Departamento de Imunobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.
authors.forename: Rebeca Pinheiro
authors.initials: RP
authors.lastname: dos Santos Barbosa
authors.affiliation: Departamento de Imunobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.
authors.forename: Thais Andressa Gonçalves
authors.initials: TA
authors.lastname: Vianna
authors.affiliation: Departamento de Imunobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.
authors.forename: Juliana
authors.initials: J
authors.lastname: Fittipaldi
authors.affiliation: Instituto de Bioquímica Médica Leopoldo De Meis, Universidade Federal do Rio de Janeiro, Brazil.
authors.forename: Mariana Pires
authors.initials: MP
authors.lastname: Teixeira
authors.affiliation: Departamento de Imunobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.
authors.forename: Fábio Barrozo
authors.initials: FB
authors.lastname: do Canto
authors.affiliation: Departamento de Imunobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil; Instituto de Bioquímica Médica Leopoldo De Meis, Universidade Federal do Rio de Janeiro, Brazil.
authors.forename: Kelli Monteiro
authors.initials: KM
authors.lastname: da Costa
authors.affiliation: Departamento de Imunobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.
authors.forename: Rodrigo Roitman
authors.initials: RR
authors.lastname: Pozzatti
authors.affiliation: Faculdade de Educação, Departamento de Fundamentos Pedagógicos, Universidade Federal Fluminense, Niterói, Brazil.
authors.forename: Vinicius Ribeiro
authors.initials: VR
authors.lastname: Cabral
authors.affiliation: Instituto de Bioquímica Médica Leopoldo De Meis, Universidade Federal do Rio de Janeiro, Brazil.
authors.forename: Vivian Mary
authors.initials: VM
authors.lastname: Rumjanek
authors.affiliation: Departamento de Imunobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil. Electronic address: luspaiva@yahoo.com.br.
authors.forename: Luciana Souza
authors.initials: LS
authors.lastname: de Paiva
mesh_terms: D000818:Animals; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D002316:Cardiotonic Agents / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D016130:Immunophenotyping; D007274:Injections, Intraperitoneal; D019041:L-Selectin / Q000235:genetics / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010042:Ouabain / Q000494:pharmacology*; D054380:Receptors, CXCR5 / Q000235:genetics / Q000276:immunology; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000187:drug effects* / Q000276:immunology
chemical_list: C513179:CXCR5 protein, mouse; D002316:Cardiotonic Agents; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D054380:Receptors, CXCR5; D019041:L-Selectin; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase
keywords: Immunoregulation; Lymph nodes; Spleen