title: Low concentrations of serum tyrosine in neuroleptic-free schizophrenics with an early onset.
abstract: The concentrations of serum tyrosine, phenylalanine and tryptophan have been determined in 23 male neuroleptic-free patients with schizophrenia and 28 male healthy control subjects. Tyrosine was significantly lower in neuroleptic-free patients with an early onset (starting before adulthood) than in healthy control subjects (p < 0.05), and the ratio of tyrosine to phenylalanine was significantly lower in neuroleptic-free patients with an early onset than in those with a late onset (starting at adulthood). No significant differences in these three amino acids were found between the patients with a late onset and healthy control subjects. The present findings suggest that there may be a disturbance of balance between tyrosine and phenylalanine in early-onset patients with schizophrenia.
authors.affiliation: Institute of Biological Psychiatry, Schizophrenia Association of Great Britain, Bangor, Gwynedd, UK.
authors.forename: J
authors.initials: J
authors.lastname: Wei
authors.forename: H
authors.initials: H
authors.lastname: Xu
authors.forename: C N
authors.initials: CN
authors.lastname: Ramchand
authors.forename: G P
authors.initials: GP
authors.lastname: Hemmings
mesh_terms: D000328:Adult; D017668:Age of Onset; D001921:Brain / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D006719:Homovanillic Acid / Q000097:blood / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010649:Phenylalanine / Q000097:blood / Q000378:metabolism; D012559:Schizophrenia / Q000097:blood* / Q000378:metabolism; D014364:Tryptophan / Q000097:blood / Q000378:metabolism; D014443:Tyrosine / Q000097:blood*
chemical_list: D014443:Tyrosine; D010649:Phenylalanine; D014364:Tryptophan; D006719:Homovanillic Acid