TY - JOUR
T1 - Intracerebroventricular injection of l-pipecolic acid exerts hypnotic effects without activating nmda receptors in neonatal chicks under social isolation-induced stress
AU - Shigemura, Asako
AU - Chowdhury, Vishwajit S.
AU - Furuse, Mitsuhiro
PY - 2020
Y1 - 2020
N2 - L-Pipecolic acid is an intermediate of L-lysine catabolism. Its central injection exerted a hypnotic effect on the brain, which was partially mediated by the activation of γ-aminobutyric acid-A and γ-aminobutyric acid-B receptors. L-Proline has also been shown to exert a similar effect on N-methyl-D-aspartate receptors. Furthermore, L-pipecolic acid is known as L-homoproline, and both L-pipecolic acid and L-proline belong to the imino acid group; therefore, it is plausible that they share certain commonalities, including similar functions. However, the role of N-methyl-D-aspartate receptors with respect to the effects of L-pipecolic acid has not been examined yet. In the present study, the relationship between N-methyl-D-aspartate receptors and the central function of L-pipecolic acid was investigated in neonatal chicks. The behavioral postures for active wakefulness and standing/sitting motionless with eyes opened were significantly affected after intracerebroventricular injection of L-pipecolic acid; whereas, sitting motionless with head drooped (sleeping posture) was significantly enhanced. However, the N-methyl-D-aspartate receptor antagonist, MK-801, did not affect these changes. In conclusion, the central administration of L-pipecolic acid did not exert hypnotic effects through the activation of N-methyl-D-aspartate receptors in neonatal chicks. These results suggest that the imino group is not a determinant for activating N-methyl-D-aspartate receptors.
AB - L-Pipecolic acid is an intermediate of L-lysine catabolism. Its central injection exerted a hypnotic effect on the brain, which was partially mediated by the activation of γ-aminobutyric acid-A and γ-aminobutyric acid-B receptors. L-Proline has also been shown to exert a similar effect on N-methyl-D-aspartate receptors. Furthermore, L-pipecolic acid is known as L-homoproline, and both L-pipecolic acid and L-proline belong to the imino acid group; therefore, it is plausible that they share certain commonalities, including similar functions. However, the role of N-methyl-D-aspartate receptors with respect to the effects of L-pipecolic acid has not been examined yet. In the present study, the relationship between N-methyl-D-aspartate receptors and the central function of L-pipecolic acid was investigated in neonatal chicks. The behavioral postures for active wakefulness and standing/sitting motionless with eyes opened were significantly affected after intracerebroventricular injection of L-pipecolic acid; whereas, sitting motionless with head drooped (sleeping posture) was significantly enhanced. However, the N-methyl-D-aspartate receptor antagonist, MK-801, did not affect these changes. In conclusion, the central administration of L-pipecolic acid did not exert hypnotic effects through the activation of N-methyl-D-aspartate receptors in neonatal chicks. These results suggest that the imino group is not a determinant for activating N-methyl-D-aspartate receptors.
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U2 - 10.2141/jpsa.0190067
DO - 10.2141/jpsa.0190067
M3 - Article
AN - SCOPUS:85078948597
VL - 57
SP - 84
EP - 87
JO - Journal of Poultry Science
JF - Journal of Poultry Science
SN - 1346-7395
IS - 1
ER -