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.
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
Ryouichi
R
Nonaka
Fumiko
F
Nagai
Akio
A
Ogata
Kanako
K
Satoh
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