Comparative study of antidepressive activity of N-terminal analogs of adrenocorticotropic hormone in rats

Abstract

Objective. The aim was to study of the effect of ACTH6-9-PGP on the level of depression in rats in the forced swimming test compared to ACTH4-7-PGP. 

Materials and methods. The experiments were performed on 90 mature Wistar male rats weighing 250-300 g. Animals were divided into 9 groups (8 experimental and 1 control) with 10 animals each. A physiological solution of 0.9% sodium chloride, ACTH6-9-PGP and ACTH4-7-PGP peptides synthesized in the Institute of Molecular Genetics, Russian Academy of Sciences, were used in the work. Peptides were administered once intraperitoneally 15 minutes before testing: ACTH6-9-PGP at the doses of 0.5, 5, 50, 150 and 450 μg/kg, ACTH4-7-PGP at the doses of 50, 150 and 450 μg/kg. The depressive behavior of rats was evaluated using a non-burdened forced swimming test. 

Results. The intraperitoneal administration of ACTH6-9-PGP at a dose of 450 μg/kg helps to reduce the time of animals’ immobilization and passive swimming, as well as to increase the duration of their active swimming, which indicates the presence of the antidepressant effect of the peptide. At the same time, ACTH4-7-PGP at all doses used did not significantly affect the studied indicators of behavioral activity, and its effects were limited only by an increase in the time of passive swimming. 

Conclusion. Thus, it was found that ACTH6-9-PGP, in contrast to ACTH4-7-PGP, is able to have an antidepressant effect.