Search

To study brain free amino acids and their relation with dementia we measured, by high-performance liquid chromatography (HPLC), the concentration of eight free amino acids, amines and related compounds. We used temporal cortex (TC) samples obtained from 13 Alzheimer's disease (AD) patients and an equal number of age-matched controls (AC). The patterns of free amino acids, amines and related compounds showed significant quantitative changes in AD conditions with respect to healthy ones. In Alzheimer patients, lower levels of GABA were found in the TC (-57 %). Amino acids glutamate (Glu), and aspartate (Asp) concentrations, also appeared significantly reduced in the TC of AD patients (Glu: -30 %; Asp: -40 %) when compared with controls. The significant gap between methionine (Met: -30 %) and cystathionine (Cysta: +60 %) levels in TC of AD people to controls, might suggest an under/over activity of the transmethylation and transsulphuration pathways, respectively. Glutamine (Gln) and Urea were an exception to this trend because their content was higher in AD patients than in controls. Albeit these compounds may have particular physiological roles, including the possible mediation of synaptic transmission, changes in amino acid levels and related compounds (detected in steady state) suggest a modified metabolic status in brains of AD patients that reveals a reduced function of synaptic transmission. Because several evidences show that patients might display quite different concentrations of neurotransmitters in brain areas, assessing metabolites in different and well-characterized AD stages should be investigated further.

Blood levels of total homocysteine (tHcy), cysteine (Cys), total and reduced glutathione (tGSH and rGSH), folic acid (FA), and vitamin B12 (B12) change during ischemic stroke as accompaniment of the tissue damage. The relationship between these changes remains scantly investigated. We evaluated the variation of these molecules in the 48 h after acute large artery atherothrombotic stroke (LAAS) and searched for the presence of matched variation of them. The study involved 50 subjects affected by acute LAAS and 49 healthy controls. Plasma levels of tHcy and Cys were significantly higher and serum levels of FA and B12 and plasma levels of rGSH were significantly lower in the patients than in the control group. Acute LAAS was associated with increased Hcy-decreased tGSH and decreased FA/tGSH. Pathways involved in cellular stress and in tissue repair are activated during acute LAAS.