Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresources and Bioenvironmental Sciences, Kyushu University, Higashi, Fukuoka, Japan.
Anim Sci J. 2009 Aug;80(4):428-32. doi: 10.1111/j.1740-0929.2009.00647.x.
L-cysteine (L-Cys) is a non-essential and glycogenic amino acid. Previously, we reported that the intracerebroventricular (i.c.v.) injection of L-Cys induced sedative effects under isolation-induced stress in neonatal chicks. L-Cys has an optical isomer, D-Cys. The aim of this study was to clarify the effect of L-Cys and D-Cys during a stressful condition in chicks. The i.c.v. injection of L-Cys and D-Cys (0.84 micromol) decreased both distress vocalization and spontaneous activity induced by isolation. However, the two cysteine isomers induced different behaviors. L-Cys increased sleep-like behavior while D-Cys caused abnormal behavior including syncope as well as sleep-like behavior. In conclusion, while both L-Cys and D-Cys caused a sedative effect when injected i.c.v, D-Cys caused abnormal behavior and may be detrimental to neonatal chicks.
L-半胱氨酸（L-Cys）是一种非必需的和糖基化氨基酸。以前，我们报道过脑室注射 L-Cys 在新生小鸡的隔离诱导应激下会产生镇静作用。L-Cys 具有光学异构体 D-Cys。本研究的目的是阐明 L-Cys 和 D-Cys 在小鸡应激状态下的作用。脑室注射 L-Cys 和 D-Cys（0.84 微摩尔）可减少隔离引起的痛苦发声和自发活动。然而，两种半胱氨酸异构体引起了不同的行为。L-Cys 增加了类似睡眠的行为，而 D-Cys 则导致了异常行为，包括晕厥和类似睡眠的行为。总之，虽然脑室注射 L-Cys 和 D-Cys 都会产生镇静作用，但 D-Cys 会导致异常行为，可能对新生小鸡有害。
