Submitted on August 31, 2005
Accepted on January 20, 2006
CHARACTERIZATION OF L-ARGININE TRANSPORT IN ADRENAL CELLS: EFFECT OF ACTH
Esteban M Repetto1, Vanesa Pannunzio1, Francisco Astort1, Camila Martinez Calejman1, Marcos Besio Moreno1, Omar Pignataro2, and Cora B Cymeryng1*
1 Departamento de Bioquimica Humana, Facultad de Medicina. Universidad de Buenos Aires, Buenos Aires, Argentina
2 IBYME, CONICET, Buenos Aires, Argentina
* To whom correspondence should be addressed. E-mail: cymeryng{at}fmed.uba.ar.
Nitric oxide synthesis depends on the availability of its precursor L-arginine which could be regulated by the presence of a specific uptake system. In the present report the characterization of the L-arginine transport system in mouse adrenal Y1 cells was performed. L-arginine transport was mediated by the cationic/neutral amino acid transport system y+L and the cationic amino acid transporter y+ in Y1 cells. These Na+ independent transporters were identified by its selectivity for neutral amino acids both in the presence and absence of Na+ and by the effect of N-ethylmaleimide. Transport data correlated to expression of genes encoding for CAT-1, CAT-2, CD-98 and y+LAT-2. A similar expression profile was detected in rat adrenal ZF. In addition, cationic amino acid uptake in Y1 cells was upregulated by ACTH and/or cAMP with a concomitant increase in nitric oxide (NO) production.
