Р.А. Кim, O.G. Voskresenskaya, A.A. Kamensky, V.P. Martinovich, V.P. Golubovich

Effects of arguinine-vasopressin (AVP) and its structural synthetic analogue Ac-D-MPRG on the white rats exploratory activity and anxiety level were studied. Peptides were administrated chronically from the 8th to the 14th days of life intranasally in the following doses: AVP - 10 mcg per kg, Ac-D-MPRG - 10 and 0,01 mcg per kg. AVP and its analogue in big dose have a pronounced anxiolytic effect in adolescent and adult rats, and both of them also decrease the level of animal emotional tensity in all age-specific groups. Administration of Ac-D-MPRG in the dose of 0,01 mcg per kg doesn-t have relative effects on anxiety-like behavior. AVP hasn-t effects on exploratory activity in both unstress and stress conditions. In the same time Ac-D-MPRG influence on this type of behavior in unstress conditions: in the dose of 10 mcg per kg it decreases the level of exploratory activity of adolescent rats and during the puberty, and in dose 0,01 mcg per kg AVP analogue has opposite effects. These changes are made conditional upon modulations of vertical and no horizontal locomotor activity. In the stress conditions effects of Ac-D-MPRG in the small dose are relative to those in the unstress environment, and in the large dose it has its own specific effects. So, in adolescent rats it increases horizontal locomotor activity, during the puberty it decreases level of exploratory behavior and has no influence on adult animals. In conclusion we can say that neonatal chronical administration of AVP and Ac-D-MPRG had postponed behavioral effects of relative direction in white rats depending on their age and on the dose of pharmacological agent.