Intracerebroventricular injection of L-arginine induces sedative and hypnotic effects under an acute stress in neonatal chicks.
L-arginine participates in many important and diverse biochemical reactions associated with the normal physiology of the organism. In the present study, we investigated the effect of central administration of L-arginine on the stress response and its mechanism in neonatal chicks. Intracerebroventricular (i.c.v.) injection of L-arginine clearly attenuated the stress response in a dose-dependent manner, and induced sleep-like behavior during 10 min. To clarify the mechanism by which L-arginine induces sedative and hypnotic effects in chicks, we investigated the effects of nitric oxide (NO) synthase (NOS) inhibitors on L-arginine-induced sedative and hypnotic effects, and as well as the effects of a NO donor. L-Arginine-induced (1.9 micromol) sedative and hypnotic effects were attenuated by i.c.v. co-injection with a non-selective NOS inhibitor N(G)-nitro-L-arginine methyl ester HCl (400 nmol). In addition, the effects of L-arginine were slightly attenuated by the inactive isomer of the NOS inhibitor N(G)-nitro-D-arginine methyl ester HCl (400 nmol). The i.c.v. injection of 3-morpholinosylnomine hydrochloride, a spontaneous NO donor, had little effect on postures. The i.c.v. injection of L-arginine had no effect on NOx concentration at various brain sites. These results suggested that the contribution of NO generation via NOS may be low in the sedative and hypnotic actions of L-arginine. Therefore, L-arginine and/or its metabolites, excluding NO, may be necessary for these actions.
Suenaga
R
R
Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresources and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan.
Tomonaga
S
S
Yamane
H
H
Kurauchi
I
I
Tsuneyoshi
Y
Y
Sato
H
H
Denbow
D M
DM
Furuse
M
M
D000208:Acute Disease; D000818:Animals; D000831:Animals, Newborn; D001120:Arginine / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects*; D001923:Brain Chemistry / Q000187:drug effects*; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013312:Stress, Physiological / Q000201:enzymology*
D004791:Enzyme Inhibitors; D006993:Hypnotics and Sedatives; D009569:Nitric Oxide; D001120:Arginine; D052248:Nitric Oxide Synthase Type I; D019331:NG-Nitroarginine Methyl Ester