Polarization of adenosine effects on intracellular pH in A6 renal epithelial cells.
Mol Pharmacol
; 51(3): 516-23, 1997 Mar.
Article
en En
| MEDLINE
| ID: mdl-9058608
The effect of adenosine on Na+/H+ exchange activity was examined in cultured A6 renal epithelial cells. Adenosine and its analogue N6-cyclopentyladenosine (CPA) had different effects on Na+/H+ exchange activity depending on the side of addition. Basolateral CPA induced a stimulation of Na+/H+ exchange activity that was completely prevented by preincubation with an A2A-selective antagonist, 8-(3-chlorostyryl)caffeine, whereas apical CPA induced a slight but significant inhibition of Na+/H+ exchange activity that was significantly reduced by the A1-receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine. Protein kinase C activation may be involved in mediating the apical CPA inhibition of Na+/H+ exchange activity; this inhibition was prevented by the protein kinase C inhibitor calphostin C. Treatment with either forskolin or 8-bromo-cAMP significantly stimulated Na+/H+ exchange activity; only basolateral CPA addition induced an increase in cAMP level. These observations together with the finding that the CPA-dependent stimulation of exchange activity was prevented by the protein kinase A inhibitor H-89 support the hypothesis that basolateral CPA stimulates Na+/H+ exchange via adenylate cyclase/protein kinase A activation. Basolateral CPA also increased transepithelial Na+ transport, and this stimulation was prevented by the Na+/H+ exchange inhibitor HOE-694, suggesting that changes in pHi during hormone action can act as an intermediate in the second-messenger cascade.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Adenosina
/
Concentración de Iones de Hidrógeno
Límite:
Animals
Idioma:
En
Revista:
Mol Pharmacol
Año:
1997
Tipo del documento:
Article
País de afiliación:
Italia
Pais de publicación:
Estados Unidos