R(-)-2,5-dimethoxy-4-77 bromoamphetamine [77Br-R(-)DOB]: a novel radioligand which labels a 5-HT binding site subtype.
R(-)-2,5-Dimethoxy-4-77Br-amphetamine [77Br-R(-)DOB], a radioligand of high specific activity (1500 +/- 200 Ci/mmol), was used to label membrane-associated recognition sites in rat brain. 77Br-R(-)DOB sites were of high affinity (KD = 0.19 nM) but low density (Bmax = 0.32 pmol/g tissue) in rat brain preparations. Competition experiments show that both 5-hydroxytryptamine (5-HT) and 5-HT2 antagonists display nanomolar potency for these sites. We conclude that 77Br-R(-)DOB labels 5-HT recognition sites in rat brain which do not fit into current classifications of 5-HT binding subtypes. This finding may be of aid in deciphering the mechanism of action of hallucinogens in man.
Wang
S S
SS
Department of Neurology, Stanford University, CA 94305.
Mathis
C A
CA
Peroutka
S J
SJ
D004290:DOM 2,5-Dimethoxy-4-Methylamphetamine / Q000031:analogs & derivatives / Q000378:metabolism*; D000662:Amphetamines / Q000378:metabolism*; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D001967:Bromine Radioisotopes; D066298:In Vitro Techniques; D011869:Radioligand Assay; D051381:Rats; D011985:Receptors, Serotonin / Q000378:metabolism*
D000662:Amphetamines; D001967:Bromine Radioisotopes; D011985:Receptors, Serotonin; D004290:DOM 2,5-Dimethoxy-4-Methylamphetamine; C003943:2,5-dimethoxy-4-bromoamphetamine