Analysis of Amino Acids in Sarcosine Treated Rat Brain by Liquid Chromatography – Mass Spectrometry with Fluorescence Detection
Date Issued
2016
Date
2016
Author(s)
Shih, Min-Han
Abstract
Amino acids analysis in biological samples is a challenging task due to complex matrix and low concentrations of amino acids. The standard analytical technique for amino acids relies on derivatization with O-phthalaldehyde (OPA), followed by HPLC and fluorescence detection. In my thesis, this technique was applied to the study of amino acid neurotransmitters in rat model of schizophrenia. Schizophrenia is a pervasive and debilitating mental disorder that severely affects more than 1 % of the population worldwide. More effective therapeutic treatments of schizophrenia are greatly required. A new hypothesis, based on the hypofunction of the N-methyl-d-aspartate receptor (NMDAR) transmission, a subtype of glutamate receptors, has emerged as a promising target on developing alternative medications to ameliorate schizophrenia symptoms. Enhance the activity of NMDAR via glycine modulation site (GMS) can improve the schizophrenia symptoms. Clinical evidence suggests that increasing synaptic glycine levels at the GMS of NMDARs is a possible approach in the treatment of schizophrenia. Unfortunately, due to the poor penetration across the blood-brain barrier, a high dosage of glycine is needed, which leads to concomitant peripheral side effects. An alternative approach to increase GMS agonist availability is to block glycine reuptake by introducing sarcosine, a naturally occurring glycine transport inhibitor, which may increase extra-synaptic glycine levels in a relatively safe manner. In this study, glycine levels in cerebrospinal fluids (CSF) of sarcosine-treated rats were detected using the OPA method. After a single dose of sarcosine, we measured CSF amino acids at two different time points (20, 80 minutes), and compared with the control group that received a single dose of saline. We found that both glycine and serine became significantly elevated after 80 minutes. Since D-serine and glycine both bind to the GMS site on NMDAR in vivo, our data provided very strong evidence to support the therapeutic effects of sarcosine.
Subjects
schizophrenia
NMDAR
sarcosine
CSF
amino acids analysis
OPA
HPLC
fluorescence detection
mass spectrometry
SDGs
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-105-R03223119-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):39e4a800cb9034cecc4f26910dd4222d