Central L-arginine reduced stress responses are mediated by L-ornithine in neonatal chicks.
Amino Acids
; 35(1): 107-13, 2008 Jun.
Article
en En
| MEDLINE
| ID: mdl-18219550
ABSTRACT
Recently, we observed that central administration of L-arginine attenuated stress responses in neonatal chicks, but the contribution of nitric oxide (NO) to this response was minimal. The sedative and hypnotic effects of L-arginine may be due to L-arginine itself and/or its metabolites, excluding NO. To clarify the mechanism, the effect of intracerebroventricular (i.c.v.) injection of L-arginine metabolites on behavior under social separation stress was investigated. The i.c.v. injection of agmatine, a guanidino metabolite of L-arginine, had no effect during a 10 min behavioral test. In contrast, the i.c.v. injection of L-ornithine clearly attenuated the stress response in a dose-dependent manner, and induced sleep-like behavior. The L-ornithine concentration in the telencephalon and diencephalon increased following the i.c.v. injection of L-arginine. In addition, several free amino acids including L-alanine, glycine, L-proline and L-glutamic acid concentrations increased in the telencephalon. In conclusion, it appears that L-ornithine, produced by arginase from L-arginine in the brain, plays an important role in the sedative and hypnotic effects of L-arginine observed during a stress response. In addition, several other amino acids having a sedative effect might partly participate in the sedative and hypnotic effects of L-arginine.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ornitina
/
Arginina
/
Estrés Fisiológico
/
Conducta Animal
/
Química Encefálica
/
Hipnóticos y Sedantes
Límite:
Animals
Idioma:
En
Revista:
Amino Acids
Asunto de la revista:
BIOQUIMICA
Año:
2008
Tipo del documento:
Article
País de afiliación:
Japón