S. Kostic-Rajacic, V. Soskic, J. Joksimović
Jan 1, 1998
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0
Influential Citations
5
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Quality indicators
Journal
Archiv der Pharmazie
Abstract
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‐propyl‐amino)ethyl]‐1,2‐diaminobenzenes. They were evaluated for in vitro binding affinity at the D1 and D2 dopamine and 5‐HT1A serotonin receptors using synaptosomal membranes of the bovine caudate nuclei and hippocampi, respectively. Tritiated SCH 23390 (D1 receptor‐selective), spiperone (D2 receptor selective) and 8‐OH‐DPAT (5‐HAT1A receptor selective) were employed as the radioligands. Only compound 6 expressed a moderate binding affinity at the dopamine D1 receptor, while the remaining ligands were inefficient or weak competitors of [3H]SCH 23390. Compound 12 was an absolutely inactive competitor of all three radioligands. Also, compound 7 was an inefficient displacer of [3H]‐8‐OH‐DPAT. Compound 19 with a Ki value of 3.5 nM was the most potent competitor of [3H]spiperone and compound 13 (Ki = 3.3 nM) was the most efficient in displacing [3H]‐8‐OH‐DPAT from the 5‐HAT1A 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.