title: Reduced monoamine oxidase activity in platelets: a possible genetic marker for vulnerability to schizophrenia.
abstract: Monoamine oxidase activity in blood platelets was measured, with [(14)C]tryptamine as substrate, in 13 monozygotic twin pairs discordant for schizophrenia and in 23 normal volunteers. The monoamine oxidase activity of both schizophrenic and nonschizophrenic co-twins was significantly lower than it was for the normals, and it was highly correlated between twins. In addition, there was a significant inverse correlation between a measure of the degree of the schizophrenic disorder and the monoamine oxidase activity. These data suggest, but do not prove, that reduced platelet monoamine oxidase activity may provide a genetic marker for vulnerability to schizophrenia.
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000201:enzymology*; D002247:Carbon Isotopes; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008995:Monoamine Oxidase / Q000097:blood* / Q000378:metabolism; D010640:Phenothiazines / Q000627:therapeutic use; D012559:Schizophrenia / Q000097:blood / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics*; D012563:Schizophrenia, Paranoid / Q000201:enzymology / Q000235:genetics; D014363:Tryptamines / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D010640:Phenothiazines; D014363:Tryptamines; D008995:Monoamine Oxidase