a School of Pharmaceutical Sciences , Southern Medical University , Guangzhou , PR China.
b College of Pharmacy , Fujian University of Traditional Chinese Medicine , Fuzhou , PR China.
Pharm Biol. 2019 Dec;57(1):280-286. doi: 10.1080/13880209.2019.1598445.
Currently, there is no cure or early preclinical diagnostic assay available for depression. Recently, depression has been observed in association with metabolic abnormalities of the glutamate (Glu)-glutamine (Gln) cycling, which is regulated by Glu, Gln and γ-aminobutyric acid (GABA) amino acids.
The purpose of this study is to determine the changes of Glu, Gln and GABA in blood and brain of chronic unpredictable mild stress (CUMS) induced mice and to clarify the depression biomarkers in the Glu-Gln cycling.
Male Kunming mice were divided into model group and control group randomly (n = 12). The depression model of mice was established by CUMS stimulation for 56 days. The liquid chromatography-fluorescence method was used for simultaneous determination of Glu, Gln and GABA in the plasma and brain of mice. o-Phthalaldehyde and β-mercaptoethanol were used as pre-column derivatization reagents. Neurotransmitters were analysed on high performance liquid chromatography (HPLC) on an HPH C18 column in combination with a fluorescence detector.
The method was simple, highly sensitive and showed excellent linearity with regression coefficients higher than 0.999, good accuracy (95-108%) and good inter-day precision (RSD <15%) for all analytes. Limit of quantification (LOQ) values were established as 0.01, 0.01 and 0.005 μg/mL for Glu, Gln and GABA. The GABA in the CUMS mouse brain (p < 0.01) was significantly increased and Gln in plasma (p < 0.01) and brain (p < 0.01) were both decreased.
Our study demonstrates that the Gln in plasma can be used as a biological marker of depression.
目前，尚无治疗或早期临床前诊断检测方法可用于治疗抑郁症。最近，人们观察到抑郁症与谷氨酸（Glu）-谷氨酰胺（Gln）循环的代谢异常有关，该循环受 Glu、Gln 和 γ-氨基丁酸（GABA）氨基酸调节。
本研究旨在确定慢性不可预测轻度应激（CUMS）诱导的小鼠血液和大脑中 Glu、Gln 和 GABA 的变化，并阐明 Glu-Gln 循环中的抑郁生物标志物。
雄性昆明小鼠随机分为模型组和对照组（n=12）。采用 CUMS 刺激 56 天建立小鼠抑郁模型。采用液相色谱-荧光法同时测定小鼠血浆和脑组织中 Glu、Gln 和 GABA。邻苯二醛和β-巯基乙醇用作柱前衍生试剂。在 HPH C18 柱上进行高效液相色谱（HPLC）分析，结合荧光检测器分析神经递质。
该方法简单、灵敏，具有良好的线性，所有分析物的回归系数均高于 0.999，准确度良好（95-108%），日内精密度良好（RSD<15%）。Glu、Gln 和 GABA 的定量限（LOQ）分别定为 0.01、0.01 和 0.005μg/mL。CUMS 小鼠大脑中的 GABA（p<0.01）显著增加，血浆（p<0.01）和大脑中的 Gln（p<0.01）均减少。
我们的研究表明，血浆中的 Gln 可作为抑郁症的生物标志物。
