[Agonistic effects of ring opened serotonin analogs of the 3-(2-aminophenyl)-3-oxopropanamine type. Pharmacology of ring opened serotonin analogs].

Intrinsic activity and affinity of various synthesized ring-opened serotonin (5-HT) analogues including 3-(2-amino-5-hydroxy-phenyl)-3-oxo-propaneamine (I) were studied using the isolated gastric fundus of the rat. For I a relative intrinsic activity of 0.83 was measured while the affinity was nearly equal to 5-HT. For the N,N-dimethyl derivative of I (V) both intrinsic activity and affinity were identical to those of bufotenine (= N,N-dimethyl serotonin). The obtained results support the postulated three-point binding of 5-HT at its D receptor.