title: Increased serum levels of glutamate in adult patients with autism.
abstract: 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.
authors.affiliation: Department of Psychiatry and Neurology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Shinohe
authors.forename: Kenji
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakamura
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Tsujii
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Iwata
authors.forename: Kenji J
authors.initials: KJ
authors.lastname: Tsuchiya
authors.forename: Yoshimoto
authors.initials: Y
authors.lastname: Sekine
authors.forename: Shiro
authors.initials: S
authors.lastname: Suda
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Suzuki
authors.forename: Gen-Ichi
authors.initials: G
authors.lastname: Sugihara
authors.forename: Hideo
authors.initials: H
authors.lastname: Matsuzaki
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Minabe
authors.forename: Toshiro
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kawai
authors.forename: Masaomi
authors.initials: M
authors.lastname: Iyo
authors.forename: Nori
authors.initials: N
authors.lastname: Takei
authors.forename: Norio
authors.initials: N
authors.lastname: Mori
mesh_terms: 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
chemical_list: D018698:Glutamic Acid