title: The effect of age on concentrations of monoamines, amino acids, and their related substances in the cerebrospinal fluid.
abstract: We studied age-related changes in the concentrations of monoamines, amino acids, and their related substances in the cerebrospinal fluid on 144 neurologically normal subjects. The concentrations of tyrosine, 3-O-methyldopa, dopamine (total), norepinephrine (total), homovanillic acid, p-hydroxyphenylacetic acid, and 5-hydroxytryptophan increased significantly with age (p < 0.05), and the concentration of 3.4-dihydroxyphenylacetic acid displayed a non-significant trend to decrease, whereas concentrations of other monoamine precursors and metabolites were unchanged. We found the significant positive correlations between the concentrations of HVA and 5-HIAA (p < 0.001), between tyrosine and tryptophan (p < 0.001), and between tyrosine and 3-O-methyldopa (p < 0.001). The concentrations of asparagine, glycine, taurine, and alanine increased significantly with age (p < 0.05), while glutamine, arginine, and threonine concentrations did not change with age. The aspartate, glutamate, and GABA concentrations displayed the non-significant trends to decrease in the elderly subjects. The concentrations of aspartate, glutamate, and GABA had mutually significant positive correlations (p < 0.05), but had significant negative correlations with the concentrations of some neutral amino acids. The urate and xanthine concentrations increased significantly with age (p < 0.01). These findings suggest that the concentrations of monoamine and amino acid transmitters and their related compounds in the cerebrospinal fluid reflect age-related changes in the synthesis, release, and reuptake mechanisms of the transmitters and their transport mechanisms across the blood-brain barrier.
authors.affiliation: Department of Neurology, Iwate Medical University, Morioka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tohgi
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Abe
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000134:cerebrospinal fluid*; D000596:Amino Acids / Q000134:cerebrospinal fluid*; D015306:Biogenic Monoamines / Q000134:cerebrospinal fluid*; D001812:Blood-Brain Barrier; D001923:Brain Chemistry / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011687:Purines / Q000134:cerebrospinal fluid; D014527:Uric Acid / Q000134:cerebrospinal fluid; D014970:Xanthines / Q000134:cerebrospinal fluid
chemical_list: D000596:Amino Acids; D015306:Biogenic Monoamines; D011687:Purines; D014970:Xanthines; D014527:Uric Acid