Ouabain-insensitive acidification by dopamine in renal OK cells: primary control of the Na+/H+ exchanger

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

gomes, p (Autor) Outra; vieira-coelho, ma (Autor) FMUP; soares-da-silva, p (Autor) FMUP

Revista

Título: American Journal of Physiology - Regulatory Integrative and Comparative Physiology

Vol. 281

Páginas: R10-R18

ISSN: 0363-6119

Editora: American Physiological Society

Indexação

ISI Web of Knowledge - 40 Citações

Scopus - 40 Citações

Classificação Científica

FOS: Ciências médicas e da saúde > Medicina básica

Outras Informações

ID Authenticus: P-000-TZ9

DOI: 10.1152/ajpregu.2001.281.1.r10

Abstract (EN): The present study was aimed at evaluating the role of D-1- and D-2-like receptors and investigating whether inhibition of Na+ transepithelial flux by dopamine is primarily dependent on inhibition of the apical Na+/H+ exchanger, inhibition of the basolateral Na+-K(+)ATPase, or both. The data presented here show that opossum kidney cells are endowed with D-1- and D-2-like receptors, the activation of the former, but not the latter, accompanied by stimulation of adenylyl cyclase (EC50 =220 +/- 2 nM), marked intracellular acidification (IC50 = 58 +/- 2 nM), and attenuation of amphotericin B-induced decreases in short-circuit current (28.6 +/- 4.5% reduction) without affecting intracellular pH recovery after CO2 removal. These results agree with the view that dopamine, through the activation of D-1- but not D-2-like receptors, inhibits both the Na+/H+ exchanger (0.001933 +/- 0.000121 vs. 0.000887 +/- 0.000073 pH unit/s) and Na+-K+-ATPase without interfering with the Na+ independent HCO3- transporter. It is concluded that dopamine, through the action of D-1- like receptors, inhibits both the Na+/H+ exchanger and Na+-K+-ATPase, but its marked acidifying effects result from inhibition of the Na+/H+ exchanger only, without interfering with the Na+-independent HCO3- transporter and Na+-K+-ATPase.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9