Mixed Dopaminergic/Serotonergic Properties of Several 2-Substituted 4-[2-(5-Benzimidazole)ethyl]-1-arylpiperazines
作者:Sladjana Kostic-Rajacic、Vukic Šoškic、Jelena Joksimovic
DOI:10.1002/(sici)1521-4184(199801)331:1<22::aid-ardp22>3.0.co;2-q
日期:1998.1
A series of substituted 4-[2-(5-benzimidazole)ethyl]-arylpiperazines was synthesized by introducing different substituents into position 2 of benzimidazole ring of 4-[2-(N,N-di-n-propylamino)ethyl]-1,2-diaminobenzenes. They were evaluated for in vitro binding affinity at the D-1 and D-2 dopamine and 5-HT1A serotonin receptors using synaptosomal membranes of the bovine caudate nuclei and hippocampi, respectively. Tritiated SCH 23390 (D-1 receptor-selective), spiperone (D-2 receptor selective) and 8-OH-DPAT (5-HT1A receptor selective) were employed as the radioligands. Only compound 6 expressed a moderate binding affinity at the dopamine D-1 receptor, while the remaining ligands were inefficient or weak competitors of [H-3]SCH 23390. Compound 12 was an absolutely inactive competitor of all three radioligands. Also, compound 7 was an inefficient displacer of [H-3]-8-OH-DPAT. Compound 19 with a K-i value of 3.5 nM was the most potent competitor of [H-3]spiperone and compound 13 (K-i = 3.3 nM) was the most efficient in displacing [H-3]-8-OH-DPAT from the 5-HT1A serotonin receptor. Ligands 5, 6, 8-11, and 13-20 expressed mixed dopaminergic/serotonergic activity in nanomolar range of concentrations with varying affinity ratios which strongly depended on the properties of the substituents introduced into position 2 of benzimidazole ring of the parent compounds.