competition of [ 3h ] 5-ht ( 15 nm ) binding by three 5-ht agonists ( 5-methoxytryptamine , 5-ht , and d-lysergic acid diethylamide ) was adequately described by a single-component system in the presence of gtp as well , even though all three agonists produced biphasic inhibition curves in the absence of the guanine nucleotide .
C0000589
5-methoxytryptamine
C0036751
5-ht