Influence of tetrapeptide Arg-Pro-Gly-Pro on the behaviour of rabbits in spontaneous and acute stress conditions

The influence of tetrapeptide Arg-Pro-Gly-Pro, i.e. the terminal fragment of tuftsin analogue TP-1, on the behaviour of rabbits was tested in spontaneous and heavy stress conditions incited by electric stimulation of ventromedial hypothalamic nucleus (Vmh). The experiment was carried out on male rabbits of chinchilla breed. The experimental groups included 8 animals each. The tetrapeptide was administered into the lateral cerebral ventricle. It was proved that in spontaneous conditions tetrapeptide did not influence significantly the change of behaviour of the animals, however, the substance influenced clearly the behaviour with Vmh stimulation. The peptide in heavy stress conditions caused shortening of aggression and tension phases, and extension of comfort and grooming phases. Tetrapeptide has a protective function in stressing conditions induced by electric stimulation of Vmh in the form of prolonging the emotionally positive behaviour of the animals.