Dipeptide "alaptide" prevented impairments in spontaneous behavior produced with trimethyltin in male rats

On the animal model of trimethyltin (TMT) induced behavioral deficits the effect of chronic treatment with spirocyclic dipeptide cyclo/alanyl-l-amino-l-cyclopentane-carbonyl (alaptide, AL) was evaluated in adult male rats.

Changes in the spontaneous behavioral repertoire were investigated in the open-field test on Day 21 (Session 1) and Day 28 (Session 2) after a single oral TMT administration.

In Experiment 1, rats given the highest TMT dose (7.5 mg/kg) exhibited significantly increased total number of behavioral patterns, the floor sniffing being the most frequent pattern. While the medium TMT dose (5 mg/kg) had a similar effect only in Session 1, the lowest TMT dose (2.5 mg/kg) was entirely ineffective. In Experiment 2, an explicit beneficial influence of both AL doses (5 and 10 mg/kg) given for 10 days before and 10 days after TMT (7.5 mg/kg) on the spontaneous behavior repertoire was observed in both Session 1 and Session 2. The total number of patterns and the time spent in individual patterns of AL+TMT treated animals did not differ from the controls and those given AL alone.

We conclude that sufficiently long AL treatment interfered with deleterious effects of TMT and forestalled changes in the structure and timing of spontaneous behavioral patterns. Thus, AL can be designated as a substance having "neuroprotective" effects.