Concentrations of serotonin and its related substances in the cerebrospinal fluid in patients with Alzheimer type dementia.
We studied concentrations of free and total serotonin (5-hydroxytryptamine, 5-HT) and its related substances in the cerebrospinal fluid from patients with Alzheimer type dementia (ATD) compared with controls. In ATD patients, concentrations of total 5-HT, tryptophan, 5-hydroxytryptophan (5-HTP), melatonin, kynurenine, and 3-hydroxykynurenine decreased significantly. The rate of concentration of tryptophan metabolites to that of tryptophan was significantly reduced for total 5-HT and 3-hydroxykynurenine only. The 5-hydroxyindoleacetic acid (5-HIAA)/5-HT ratio was significantly larger in ATD patients than in controls. The greater reduction in the 3-hydroxykynurenine concentration (81% vs. controls) than in the total 5-HT concentration (51% vs. controls) suggests that the metabolism of tryptophan to 5-HT and 3-hydroxykynurenine is in favor of 5-HT.
Tohgi
H
H
Department of Neurology, Iwate Medical University, Morioka, Japan.
Abe
T
T
Takahashi
S
S
Kimura
M
M
Takahashi
J
J
Kikuchi
T
T
D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000523:psychology; D000596:Amino Acids / Q000134:cerebrospinal fluid; D006801:Humans; D008875:Middle Aged; D012701:Serotonin / Q000134:cerebrospinal fluid*
D000596:Amino Acids; D012701:Serotonin