Kiriyama Yoshimitsu, Nochi Hiromi
Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Sanuki, Kagawa 769-2193, Japan.
Scientifica (Cairo). 2016;2016:6494621. doi: 10.1155/2016/6494621. Epub 2016 Dec 8.
Amino acids are important components for peptides and proteins and act as signal transmitters. Only L-amino acids have been considered necessary in mammals, including humans. However, diverse D-amino acids, such as D-serine, D-aspartate, D-alanine, and D-cysteine, are found in mammals. Physiological roles of these D-amino acids not only in the nervous system but also in the endocrine system are being gradually revealed. N-Methyl-D-aspartate (NMDA) receptors are associated with learning and memory. D-Serine, D-aspartate, and D-alanine can all bind to NMDA receptors. HS generated from D-cysteine reduces disulfide bonds in receptors and potentiates their activity. Aberrant receptor activity is related to diseases of the central nervous system (CNS), such as Alzheimer's disease, amyotrophic lateral sclerosis, and schizophrenia. Furthermore, D-amino acids are detected in parts of the endocrine system, such as the pineal gland, hypothalamus, pituitary gland, pancreas, adrenal gland, and testis. D-Aspartate is being investigated for the regulation of hormone release from various endocrine organs. Here we focused on recent findings regarding the synthesis and physiological functions of D-amino acids in the nervous and endocrine systems.
氨基酸是肽和蛋白质的重要组成部分，并充当信号传递分子。在包括人类在内的哺乳动物中，仅L-氨基酸被认为是必需的。然而，在哺乳动物中发现了多种D-氨基酸，如D-丝氨酸、D-天冬氨酸、D-丙氨酸和D-半胱氨酸。这些D-氨基酸不仅在神经系统而且在内分泌系统中的生理作用正逐渐被揭示。N-甲基-D-天冬氨酸（NMDA）受体与学习和记忆相关。D-丝氨酸、D-天冬氨酸和D-丙氨酸都能与NMDA受体结合。由D-半胱氨酸产生的HS可减少受体中的二硫键并增强其活性。受体活性异常与中枢神经系统（CNS）疾病有关，如阿尔茨海默病、肌萎缩侧索硬化症和精神分裂症。此外，在松果体、下丘脑、垂体、胰腺、肾上腺和睾丸等部分内分泌系统中检测到了D-氨基酸。正在研究D-天冬氨酸对各种内分泌器官激素释放的调节作用。在此，我们重点关注了关于D-氨基酸在神经和内分泌系统中的合成及生理功能的最新研究结果。
