Dextromethorphan inhibits 5-hydroxytryptamine uptake by human blood platelets and decreases 5-hydroxyindoleacetic acid content in rat brain.
The effect of dextromethorphan on the uptake and metabolism of 5-hydroxytryptamine (5-HT) was studied in human blood platelets and in rat brain. In the concentration of 120 nM dextromethorphan inhibited the uptake of 5-HT (1 mu-M) into platelets by 50%. The corresponding concentrations of imipramine and methadone under similar conditions were 22 and 590 nM, respectively. Dextromethorphan (20 to 40 mg kg-1) decreased the concentration of brain 5-hydroxyindoleacetic acid (5-HIAA) and the probenecid-induced accumulation of 5-HIAA time- and dose-dependently. However, dextromethorphan did not alter the pargyline-induced changes in brain 5-HT metabolism. Dextromethorphan-induced changes in brain 5-HT metabolism could arise from the inhibition of the re-uptake of 5-HT into neurons.
D000818:Animals; D001792:Blood Platelets / Q000378:metabolism*; D001923:Brain Chemistry / Q000187:drug effects*; D003864:Depression, Chemical; D003915:Dextromethorphan / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism*; D066298:In Vitro Techniques; D007981:Levorphanol / Q000031:analogs & derivatives*; D051381:Rats; D012701:Serotonin / Q000378:metabolism*
D007981:Levorphanol; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D003915:Dextromethorphan