Hyperserotonemia in autism: activity of 5HT-associated platelet proteins.
Disturbances in serotonin (5HT) neurotransmission have been indicated as biological substrates in several neuropsychiatric disorders including autism. Blood 5HT concentrations, elevated in about one-third of autistic subjects, are regulated through the action of peripheral 5HT-associated proteins. We have measured the activity of two platelet 5HT-associated proteins: 5HT transporter (5HTT) and monoamine oxidase B (MAOB), and indirectly studied the activity of 5HT(2A) receptor (5HT(2A)r) in 15 hyperserotonemic (HS) and 17 normoserotonemic (NS) autistic subjects, and 15 healthy controls (C). While mean velocities of 5HTT kinetics did not significantly differ among the groups, significant elevation in the mean velocity of MAOB kinetics was observed in NS subjects and was even more pronounced in HS subjects in comparison to controls. Also, a decrease in adenosine 5'-diphosphate-induced platelet aggregation of borderline significance was observed in NS subjects, compared to C subjects. The results suggest a possibility of upregulation of monoaminergic synthesis/degradation and, probably consequential, downregulation of 5HT(2A)r in autistic subjects.
Hranilović
Dubravka
D
Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10 000, Zagreb, Croatia. dubravka@biol.pmf.hr
Bujas-Petković
Zorana
Z
Tomicić
Maja
M
Bordukalo-Niksić
Tatjana
T
Blazević
Sofia
S
Cicin-Sain
Lipa
L
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D001321:Autistic Disorder / Q000097:blood*; D001792:Blood Platelets / Q000378:metabolism*; D003029:Coagulants / Q000494:pharmacology; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D008995:Monoamine Oxidase / Q000097:blood*; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology; D010976:Platelet Count; D044402:Receptor, Serotonin, 5-HT2A / Q000097:blood*; D012701:Serotonin / Q000097:blood*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000097:blood*; D055815:Young Adult
D003029:Coagulants; D044402:Receptor, Serotonin, 5-HT2A; D050486:Serotonin Plasma Membrane Transport Proteins; D012701:Serotonin; D000244:Adenosine Diphosphate; D008995:Monoamine Oxidase