Increased serum levels of glutamate in adult patients with autism.
BACKGROUND
Precise mechanisms underlying the pathophysiology of autism are currently unknown. Given the major role of glutamate in brain development, we have hypothesized that glutamatergic neurotransmission plays a role in the pathophysiology of autism. In this study, we studied whether amino acids (glutamate, glutamine, glycine, D-serine, and L-serine) related to glutamatergic neurotransmission are altered in serum of adult patients with autism.


METHODS
We measured serum levels of amino acids in 18 male adult patients with autism and age-matched 19 male healthy subjects using high-performance liquid chromatography.


RESULTS
Serum levels (mean = 89.2 microM, S.D. = 21.5) of glutamate in the patients with autism were significantly (t = -4.48, df = 35, p < 0.001) higher than those (mean = 61.1 microM, S.D. = 16.5) of normal controls. In contrast, serum levels of other amino acids (glutamine, glycine, d-serine, l-serine) in the patients with autism did not differ from those of normal controls. There was a positive correlation (r = 0.523, p = 0.026) between serum glutamate levels and Autism Diagnostic Interview-Revised (ADI-R) social scores in patients.


CONCLUSIONS
The present study suggests that an abnormality in glutamatergic neurotransmission may play a role in the pathophysiology of autism.
Shinohe
Atsuko
A
Department of Psychiatry and Neurology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan.
Hashimoto
Kenji
K
Nakamura
Kazuhiko
K
Tsujii
Masatsugu
M
Iwata
Yasuhide
Y
Tsuchiya
Kenji J
KJ
Sekine
Yoshimoto
Y
Suda
Shiro
S
Suzuki
Katsuaki
K
Sugihara
Gen-Ichi
G
Matsuzaki
Hideo
H
Minabe
Yoshio
Y
Sugiyama
Toshiro
T
Kawai
Masayoshi
M
Iyo
Masaomi
M
Takei
Nori
N
Mori
Norio
N
D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000097:blood* / Q000175:diagnosis / Q000523:psychology; D018698:Glutamic Acid / Q000097:blood*; D006801:Humans; D008297:Male; D008487:Medical History Taking; D011581:Psychological Tests; D012016:Reference Values
D018698:Glutamic Acid