In vitro screening of psychoactive drugs by [(35)S]GTPgammaS binding in rat brain membranes.
We constructed a reproducible, simple, and small-scale determination method of the psychoactive drugs that acted directly on the monoamine receptor by measuring the activation of [(35)S]guanosine-5'-O-(3-thio)-triphosphate binding to guanine nucleotide-binding proteins (G proteins). This method can simultaneously measure the effects of three monoamines, namely dopamine (DA), serotonin (5-HT), and norepinephrine (NE), in rat brain membranes using a 96-well microplate. Activation of D(1) and D(2) receptors in striatal membranes by DA as well as 5-HT and NEalpha(2) receptors in cortical membranes could be measured. Of 12 tested phenethylamines, 2,5-dimethoxy-4-chlorophenethylamine (2C-C), 2,5-dimethoxy-4-ethylphenethylamine (2C-E), and 2,5-dimethoxy-4-iodophenethylamine (2C-I) stimulated G protein binding. The other phenethylamines did not affect G protein binding. All 7 tryptamines tested stimulated G protein binding with the following rank order of potency; 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT)>5-methoxy-N,N-diallyltryptamine (5-MeO-DALT)>5-methoxy-alpha-methyltryptamine (5-MeO-AMT)>or=5-methoxy-N,N-methylisopropyltryptamine (5-MeO-MIPT)>5-methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT)>N,N-dipropyltryptamine (DPT)>or=alpha-methyltryptamine (AMT). This assay system was able to designate psychoactive drugs as prohibited substances in accordance with criteria set forth by the Tokyo Metropolitan government.
Nonaka
Ryouichi
R
Department of Environmental Health and Toxicology, Tokyo Metropolitan Institute of Public Health, 3-24-1 Hyakunincho, Shinjuku-ku, Tokyo 169-0073, Japan. Ryouichi_Nonaka@member.metro.tokyo.jp
Nagai
Fumiko
F
Ogata
Akio
A
Satoh
Kanako
K
D000498:Allyl Compounds / Q000378:metabolism; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D010627:Phenethylamines / Q000378:metabolism; D010879:Piperazines / Q000378:metabolism; D011619:Psychotropic Drugs / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism; D013329:Structure-Activity Relationship; D013462:Sulfur Radioisotopes; D014363:Tryptamines / Q000378:metabolism
D000498:Allyl Compounds; D010627:Phenethylamines; D010879:Piperazines; D011619:Psychotropic Drugs; D013462:Sulfur Radioisotopes; D014363:Tryptamines; D012701:Serotonin; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D019204:GTP-Binding Proteins; C578955:N,N-diallyl-5-methoxytryptamine; D009638:Norepinephrine