Evidence for distinct phencyclidine and SKF10047 receptors following detergent treatment of rat brain membranes

The sigma-selective ligand NE-100 attenuates the effect of phencyclidine in a rat diving model

1. Phencyclidine (PCP) reduces the latency of rats diving into a water-filled pool from a hidden platform, without stereotyped behavior. 2. The sigma-selective ligand, NE-100 (N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)phenyl]-ethyl-amine monohydrochloride), attenuates the effects of PCP in this procedure. 3. The serotonin2 (5-HT2) antagonist, ritanserin, and the sigma receptor ligands, 1-(cyclopropylmethyl)-4-[2'(4"-fluorophenyl)-2'-oxoethyl]- piperidine HBr (Dup734), 4-[2'-(4"-cyanophenyl)-2'-oxoethyl]-1- (cyclopropylmethyl)piperidine (XJ448), alpha-(4-fluorophenyl)-4-(5-fluoro-2-pyrimidinyl)-1-piperazine butanol (BMY14802) and rimcazole similarly attenuate the effects of PCP. 4. The dopamine D2/sigma ligands, haloperidol and cis-N-(1-benzyl-2-methyl-pyrrolidin-3-yl)-2-methoxy-5-chloro-4- methylaminobenzamide (YM-09151-2) completely reverse the effects of PCP, whereas the same dose ranges of these drugs produce sedation. 5. The dopamine D2-selective antagonist, sulpiride, has no apparent effect on the PCP latency to the rat dive. 6. Thus, PCP-induced diving behavior was improved by sigma ligands and the 5-HT2 antagonist. This model of negative symptoms in an experimental animal will facilitate experiments on drug treatments for schizophrenia.

Effect of NE-100, a novel sigma receptor ligand, on phencyclidine-induced cognitive dysfunction

N,N-Dipropyl-2-[4-methoxy-3-(2-phenylethoxy)phenyl]-ethylamine monohydrochloride (NE-100) is a selective and potent sigma receptor ligand. We investigated the effects of NE-100 on phencyclidine (PCP)-induced cognitive dysfunction in rats in a water maze task. NE-100 significantly shortened the PCP-induced prolonged swimming latency as did 1-(cyclopropylmethyl)-4-[2'(4"-fluorophenyl)-2'-oxoethyl]- piperidine monohydrobromide (Dup 734), 4-[2'-(4"-cyanophenyl)-2'-oxoethyl]-1-(cyclopropyl-methyl)pi peridine (XJ 448), alpha-(4-fluorophenyl)-4-(5-fluoro-2-pyrimidinyl)-1-piperazine butanol (BMY 14802) and rimcazole, all of which are sigma receptor ligands and possibly antagonists. Ritanserin, a 5-HT2 receptor antagonist, also showed a tendency to shorten swimming latencies. Latencies of haloperidol-, cis-N-(1-benzyl-2-methyl-pyrrolidin-3-yl)-2-methoxy-5-chloro-4-met hyl- aminobenzamide (YM-09151-2)- and sulpiride-, dopamine D2 receptor antagonists, treated groups did not differ from that seen in the PCP-treated group. Thus, PCP-induced cognitive dysfunction may be improved by sigma receptor ligands.

NE-100, a novel sigma receptor ligand: effect on phencyclidine-induced behaviors in rats, dogs and monkeys

Phencyclidine (PCP)-induced psychosis is a useful animal model for studies on schizophrenia. N, N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)-phenyl]- ethylamine monohydrochloride (NE-100) had no effect on conditioned avoidance responses (CAR) in rats, whereas, the PCP-induced impairment of avoidance inhibition was attenuated by NE-100. The PCP-induced ataxia or decreased attention in rhesus monkeys was to some extent overcome by NE-100. In dogs, PCP-induced either head-weaving behavior or ataxia, effects which were blocked by NE-100. Administration of PCP led to an increase in beta-2 and a decrease in delta relative power (RP) activity in cortical background spectral electroencephalographics (ECoG) in dogs. While NE-100 in itself showed no significant change in beta-2 and delta RP, NE-100 did block the PCP-induced beta-2 increase and delta decrease. These findings indicate that NE-100 attenuates the effect of PCP in experimental animals. This drug is being considered as a therapeutic for the treatment of patients in the schizophrenia.