zimeldine and pirenperone

The mechanism of action of 5-hydroxytryptophan (5-HT, 10 mg/kg), quipazin (7 mg/kg), zimelidin (15 mg/kg) and m-chlorophenylpiperazine (5 mg/kg) was examined with the aid of some analyzer substances. The avoidance behavior under stress was used as criterion of estimation. The optimizing effect of 5-HT on the avoidance behavior was demonstrated to be a consequence of serotonin synthesis activation and its release with activation of postsynaptic 5-HT-1-receptors. An adverse effect of quipazin on the avoidance behavior was, to a greater degree, due to the activation of 5-HT-2-autoreceptors rather than of dopamine receptors. The inhibitory effect of m- chlorphenylpiperazine was reversed by administration of pyrenepyrone , a blocker of 5-HT-2-receptors. The inhibitory effect of zimelidine on the avoidance behavior was not removed by clonidin . The positive effect on the avoidance behavior under stress occurs as a result of exposures that activate the synthesis and release of 5-HT as well as of activation of postsynaptic 5-HT-1 receptors.

Topics: 5-Hydroxytryptophan; Acute Disease; Animals; Avoidance Learning; Cyproheptadine; Humans; Hydrazines; Male; Piperazines; Piperidines; Quinolines; Quipazine; Rats; Rats, Inbred Strains; Stress, Psychological; Tranquilizing Agents; Zimeldine

The data are provided on the effect of some serotoninergic substances on the avoidance behavior under acute stress. 5-Hydroxytryptophan, zimelidine (low doses), pyrenepyron, ciproheptadine, trazodon (high doses), produced a noticeable positive action on the behavior pattern under study. Quipazin and zimelidine (high doses) provoked an increase in the number of affective manifestations and a rise of the latent avoidance time. Regardless of an appreciable fall in the number of affective manifestations, the powerful sedative effect of m-chlorphenylpiperazine led to an increase in the latent response periods. It was shown that substances that produced a direct or mediated activation effect on the serotoninergic system had an appreciable favourable influence on the avoidance behavior, which was a consequence of a decrease in the animals' emotional excitement. Combination of serotonin-blocking properties (action on S2-autoreceptors) and dopaminergic properties brought about optimal results, provided that pyrenepyron was applied.

Topics: 5-Hydroxytryptophan; Animals; Antidepressive Agents; Brompheniramine; Cyproheptadine; Escape Reaction; Humans; Male; Piperazines; Piperidines; Quipazine; Rats; Rats, Inbred Strains; Serotonin; Stress, Psychological; Tranquilizing Agents; Trazodone; Zimeldine