[The anxiolytic action of an analog of the endogenous peptide tuftsin on inbred mice with different phenotypes of the emotional stress reaction].

The anxiolytic effect of the synthetic analogue of the endogenous peptide tuftsin (Thr-Lys-Pro-Arg-Pro-Gly-Pro) was studied in inbred mice Balb/c (C) and C57B1/6 (B6) with different heritable types of emotional-stress reaction. In C strain with genetically high level of anxiety and "passive" type of behaviour under conditions of avoidable and unavoidable stress (open field, elevated plus-maze, light-dark chamber) the heptapeptide prevented manifestations of anxiety being administered intraperitoneally in a wide range of active doses (200-3000 mcg/kg). The drug did not change the behaviour of B6 mice with low level of anxiety and active type of emotional-stress reaction. The described effect is comparable with tranquilizing-activatory action of low doses of benzodiazepine tranquillizers, however, in contrast to the latter, the heptapeptide has no side inhibitory behavioural effects even in high doses. The heptapeptide may be considered as a promising new anxioselective drug without side inhibitory behavioural effects which are typical for benzodiazepine tranquillizers.