title: Expression of angiotensin I-converting enzymes and bradykinin B2 receptors in mouse inner medullary-collecting duct cells.
abstract: We described in mouse inner medullary-collecting duct cells (mIMCD-3) the somatic and the N-domain ACE synthesis and its interaction with the kallikrein-kinin system co-localized in the same cells. We purified two ACE forms from culture medium, M1 (130 kDa) and M2 (N-domain, 60 kDa), and cellular lysate, C1 (130 kDa) and C2 (N-domain, 60 kDa). Captopril and enalaprilat inhibited the purified enzymes. The immunofluorescence studies indicated that ACE is present in the membrane, cytoplasm and in the cell nucleus. Kinin B1 and B2 receptors were detected by immunofluorescence and showed to be activated by BK and DesR9 BK, increasing the acidification rate which was enhanced in the presence of enalaprilat. The presence of secreted and intracellular ACE in mIMCD-3 confirmed the hypothesis previously proposed by our group for a new site of ACE secretion in the collecting duct.
authors.affiliation: Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Medicina, Disciplina de Nefrologia, 04023-900, São Paulo, SP, Brazil.
authors.forename: Beata Marie
authors.initials: BM
authors.lastname: Redublo Quinto
authors.forename: Maria Claudina
authors.initials: MC
authors.lastname: Camargo de Andrade
authors.forename: Fernanda Aparecida
authors.initials: FA
authors.lastname: Ronchi
authors.forename: Edson Lucas
authors.initials: EL
authors.lastname: Santos
authors.forename: Silvana Aparecida
authors.initials: SA
authors.lastname: Alves Correa
authors.forename: Suma Imura
authors.initials: SI
authors.lastname: Shimuta
authors.forename: João Bosco
authors.initials: JB
authors.lastname: Pesquero
authors.forename: Renato Arruda
authors.initials: RA
authors.lastname: Mortara
authors.forename: Dulce Elena
authors.initials: DE
authors.lastname: Casarini
mesh_terms: D000818:Animals; D002216:Captopril / Q000494:pharmacology; D002478:Cells, Cultured; D015773:Enalaprilat / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D007679:Kidney Medulla / Q000201:enzymology*; D007685:Kidney Tubules, Collecting / Q000201:enzymology*; D051379:Mice; D007703:Peptidyl-Dipeptidase A / Q000032:analysis / Q000302:isolation & purification*; D043782:Receptor, Bradykinin B2 / Q000032:analysis*
chemical_list: D043782:Receptor, Bradykinin B2; D002216:Captopril; D007703:Peptidyl-Dipeptidase A; D015773:Enalaprilat