title: Orally administered L-ornithine elevates brain L-ornithine levels and has an anxiolytic-like effect in mice.
abstract: Intracerebroventricular injection of L-ornithine has demonstrated sedative and hypnotic effects in neonatal chicks exposed to acute stressful conditions. However, whether orally administered L-ornithine can reduce acute mental stress remains to be defined. To clarify the nutritional importance of L-ornithine in controlling the stress response, in Experiment 1 we first investigated whether orally administered L-ornithine can be transported into the brain of mice. Mice were orally administered L-ornithine (3 mmol/water 10 ml/kg, per os). L-Ornithine levels were significantly elevated in the cerebral cortex and hippocampus at 30 and 60 minutes post-administration. In Experiment 2, the effect of orally administered L-ornithine (0, 0.1875, 0.75 and 3 mmol/water 10 ml/kg, per os) on anxiety-like behavior in mice exposed to the elevated plus-maze test was examined at 30 minutes post-administration. There was a significant increase in the percentage of time spent and entries in the open arms in the group receiving 0.75 mmol of L-ornithine compared to the control group. Furthermore, locomotion activity in a novel environment was not significantly changed between the control group and 0.75 mmol of L-ornithine group in Experiment 3. Therefore, it appears that orally administrated L-ornithine is bioavailable to the rodent brain and reduces anxiety-like behavior as demonstrated by the elevated plus-maze test.
authors: Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan.
authors: Koji
authors: K
authors: Kurata
authors: Mao
authors: M
authors: Nagasawa
authors: Shozo
authors: S
authors: Tomonaga
authors: Mami
authors: M
authors: Aoki
authors: Koji
authors: K
authors: Morishita
authors: D Michael
authors: DM
authors: Denbow
authors: Mitsuhiro
authors: M
authors: Furuse
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000378:metabolism / Q000627:therapeutic use*; D001007:Anxiety / Q000178:diet therapy* / Q000209:etiology; D001120:Arginine / Q000378:metabolism; D001522:Behavior, Animal; D001921:Brain / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D002956:Citrulline / Q000378:metabolism; D019587:Dietary Supplements; D005106:Exploratory Behavior; D006624:Hippocampus / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009952:Ornithine / Q000008:administration & dosage / Q000378:metabolism / Q000627:therapeutic use*; D013315:Stress, Psychological / Q000503:physiopathology; D013997:Time Factors
chemical_list: D014151:Anti-Anxiety Agents; D002956:Citrulline; D001120:Arginine; D009952:Ornithine