Dopamine D-1-like receptor-mediated inhibition of Cl-/HCO3- exchanger activity in rat intestinal epithelial IEC-6 cells is regulated by G protein-coupled receptor kinase 6 (GRK 6)

• Tipo: Artigo em Revista Científica Internacional
• Data: 2006

Autores

Sonia Fraga (Autor) FFUP; Luo, YJ (Autor) Outra; Jose, PA (Autor) Outra; Zandi Nejad, K (Autor) Outra; Mount, DB (Autor) Outra; soares-da-silva, p (Autor) FMUP

Revista

Título: Cellular Physiology and Biochemistry

Vol. 18

Páginas: 347-360

ISSN: 1015-8987

Editora: Cell Physiol Biochem Press

Indexação

ISI Web of Knowledge - 8 Citações

Scopus - 7 Citações

Outras Informações

ID Authenticus: P-004-P9R

DOI: 10.1159/000097612

Abstract (EN): The present study investigated the effect of dopamine D-1-like receptor stimulation on the Cl-/HCO3- exchange activity in rat intestinal epithelial IEC-6 cells. The Cl-/ HCO3-exchange activity was found to be a chloride-dependent, DIDS-sensitive and niflumate-insensitive process. The presence of the SLC26A6 anion exchanger was detected by both RT-PCR and immunoblotting analysis in IEC-6 cells, in which three different small interfering RNAs (siRNAs) targeting SLC26A6 markedly inhibited Cl-/HCO3(-) exchange. Activation of dopamine D-1-like receptors with SKF 38393 inhibited Cl-/HCO3- exchanger activity, this being antagonized by the D 1 selective antagonist SKF 83566. However, effects of SKF 38393 were maximal at 5 min of exposure to the agonist and rapidly diminished with no effect at 15 min, suggestive of agonist-induced desensitization of D-1-like receptors. Pretreatment of cells with heparin, a non-selective inhibitor of G protein-coupled receptor kinases (GRKs), prevented the observed attenuation of SKF 38393-induced inhibition of Cl-/HCO3- exchange. Overnight pretreatment with anti-GRK6A and antiGRK6B, but not with anti-GRK4 antibodies, prevented the loss of SKF 38393-mediated effects. Both PKA and PKC signaling pathways participate in SKF 38393-mediated inhibition of Cl-/HCO3- exchange. These findings suggest that SLC26A6 is at least one of the anion exchanger's family members responsible for Cl-/HCO3- exchange in IEC-6 cells. Dopamine D-1 receptors in IEC-6 rapidly desensitize to D-1-like agonist stimulation and GRK 6, but not GRK 4, appear to be involved in agonist-mediated responsiveness and desensitization.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 14