IQUIFIB   02644
INSTITUTO DE QUIMICA Y FISICOQUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Unidad Ejecutora - UE
artículos
Título:
Urodilatin and dopamine: A new interaction in the kidney.
Autor/es:
CITARELLA MR, CHOI MR, GIRONACCI MM, MEDICI C, CORREA AH, FERNÁNDEZ BE
Revista:
REGULATORY PEPTIDES
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2009 vol. 153 p. 19 - 24
ISSN:
0167-0115
Resumen:
Since renal natriuretic peptide urodilatin (URO) exerts similar natriuretic and diuretic actions to those of atrial natriuretic factor (ANF), we hypothesized that URO regulates renal dopamine (DA) availability, contributing  to Na+, K+-ATPase inhibition. URO (1–100 nM) increased 3H-DA uptake in outer and juxtamedullar renal  cortex and medulla slices from Sprague Dawley rats. Hydrocortisone blocked URO-stimulated DA  uptake, demonstrating that DA uptake was extraneuronal. The natriuretic peptide receptor type A antagonist anantin blocked URO-dependent increase of 3H-DA uptake, while the natriuretic peptide receptor type C agonist ANF -amide did not modify URO effect on DA uptake, suggesting that only  natriuretic receptors type A are involved. Co-incubation of URO and ANF did not show additive effects on DA uptake. To test whether URO effect involves changes in Na+, K+-ATPase activity we performed experiments in renal cortex samples of  rats with DA synthesis and neuronal uptake inhibited by carbidopa and nomifensine, respectively. When endogenous DA synthesis was inhibited, URO or DA decreased Na+, K+-ATPase activity. URO and DA added together, further decreased Na+, K+-ATPase activity showing an additive effect on the sodium pump. Moreover, hydrocortisone reversed URO-DA over-inhibition of the enzyme, confirming that this inhibition is closely related to URO-stimulation on renal DA uptake. URO and DA could act via a common intracellular pathway to decrease sodium and water tubular reabsorption, contributing to its natriuretic and diuretic effects.