1-(1-Naphthyl)piperazine (1-NP) is a ligand for serotonin (5-hydroxytryptamine, 5-HT) receptors. It acts as an antagonist for 5-HT at 5-HT1 and 5-HT2 in rat cortical membranes with IC50 values of 6 and 1 nM, respectively. 1-NP also blocks contraction in the rat fundus induced by either 5-HT or tryptamine (IC50 = 1 nM for both agonists). 1-NP mimics the 5-HT1 agonist 1-(m-trifluoromethylphenyl)piperazine (TFMPP, ) in decreasing 5-HT receptor turnover and increasing serum corticosterone, suggesting that, in the absence of 5-HT, 1-NP may act as an agonist of the 5-HT1 receptor. However, in squirrel monkeys, 1-NP acts as a non-selective 5-HT receptor antagonist in altering operant behavior. 1-NP also binds to the human 5-HT6 receptor with an affinity comparable to that of 5-HT (Kis = 120 and 100 nM, respectively).
1-(1-Naphthyl)piperazinemiddotHCl is a mixed agonist/antagonist of the serotonin receptors.
1-np binds to human 5- ht6 (h5-ht6) serotonin receptors with a ki of 120 nm [1]. in rat cortical membranes, 1-np inhibited the activity of 5-ht1 and 5-ht2 with ic50 values of 6 and 1 nm, respectively. 1-np also blocked contraction in the rat fundus induced by either 5-ht or tryptamine with an ic50 of 1 nm [3].
in squirrel monkeys, 1-np (0.3–1.0 mg/kg) blocked the decrease of responding under fixed-interval (fi) schedules of presentation of food caused by dob (0.01–0.3 mg/kg), an agonist of 5-ht2. 1-np also antagonized the decreases in responding produced by quipazine (0.1–5.6 mg/kg), another agonist with predominant 5-ht2 actions [4].
[1] lee m, rangisetty j b, pullagurla m r, et al. 1-(1-naphthyl) piperazine as a novel template for 5-ht 6 serotonin receptor ligands[j]. bioorganic & medicinal chemistry letters, 2005, 15(6): 1707-1711.
[2] nichols d e, nichols c d. serotonin receptors[j]. chemical reviews, 2008, 108(5): 1614-1641.
[3] cohen m l, wittenauer l a. relationship between serotonin and tryptamine receptors in the rat stomach fundus[j]. journal of pharmacology and experimental therapeutics, 1985, 233(1): 75-79.
[4] mckearney j w. serotonin-antagonist effects of 1-(1-naphthyl) piperazine on operant behavior of squirrel monkeys[j]. neuropharmacology, 1989, 28(8): 817-821.
