It was found that GK-2 at a daily dose of 1 mg/kg, intraperitoneally, during 7 days statistically significantly reduces brain infarct volume by 20-60% at the first injection from 4 to 24h, with the highest effect 6-8 hours after surgery. Thus, the 'therapeutic window' of GK-2 detected in the experiment is no less than 24 hours, which exceeds the existing neuroprotective agents.

The translocator protein (TSPO) promotes the translocation of cholesterol to the inner mitochondrial membrane and mediates steroid formation. In this study, we first report on a biological evaluation of the dipeptide GD-23 (N-carbobenzoxy-L tryptophanyl-L isoleucine amide), a structural analogue of Alpidem, the principal TSPO ligand. We show that GD-23 in a dose range of 0.05 to 0.5 mg/kg (i.p.) exhibits anxiolytic activity in the elevated plus maze test and nootropic activity in the object recognition test in scopolamine-induced amnesia in rodents. It was shown that GD-23 did not affect spontaneous locomotor activity, holding promise as a nonsedative anxiolytic agent. The anxiolytic and nootropic activities of GD-23 were abrogated by the TSPO specific ligand PK11195, which thus suggests a role for TSPO in mediating the pharmacological activity of GD-23.