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The behavioral and biochemical effects of a new dipeptide mimetic of the GK-2 nerve growth factor (NGF) have been studied on a model of chronic cerebral ischemia induced by permanent common carotid artery occlusion in rats. It is established that subchronic intraperitoneal injections of GK-2 (0.5 mg/kg) 4 h after surgery, followed by seven more injections made every 24 h, fully prevent the death of operated animals and reduces the development of habitation deficit (open-field test) and decrease in exploratory activity (novel object examination) two weeks after surgery, as well as fully restores the viability of cerebral cortex cells and decreases the hyperexpression of HSP70 in cerebral cortex.

The effects of acute and subchronic administration of antiparkinsonian drugs hemantane and amantadine on dopamine transporter (DAT) content in the brain of normal and MPTP-treated mice have been studied. MPTP treatment (30 mg/kg, daily for 2 days, i.p.) led to an insignificant decrease of the DAT level in striatum, while not influencing the DAT content in the frontal cortex of mice. The acute administration of hemantane (20 mg/kg, i.p.) failed to influence the DAT levels in the tested structures of mice brain, while amantadine (13.9 mg/kg, i.p) decreased the DAT level but only in striatum. The acute administration of a drug (hemantane or amantadine) simultaneously with MPTP toxin reduced the DAT levels in striatum but did change the DAT concentration in the frontal cortex. On the contrary, the subchronic injection of hemantane alone (7 x 20 mg/kg, i.p.) and in combination with the toxin increased the DAT levels in the brain structures, while amantadine (7 x 13.9 mg/kg, i.p.) led to a pronounced increase of DAT concentration only in the striatum. Thus, both similar and dissimilar trends in the neurochemical effects of hemantane and amantadine have been experimentally revealed.

Experiments in vitro showed that dimeric linear substituted dipeptide GK-2-a new mimetic of the nerve growth factor (NGF) - introduced in a concentration of 10(-5) M and 10(-8) M in the culture of immortalized murine hippocampal cell line HT-22 increases the synthesis of heat shock proteins HSP32 and HSP70 (neuroprotectors belonging to the endogenous system of cell protection) and stimulates tyrosine phosphorylation of TrkA receptor, which is specific for neurotrophins.

Experiments in anesthetized rats showed that global transient brain ischemia caused a significant decrease in cerebral blood flow in rat cerebral cortex and reduced the stress protein HSP70 level in striatum. Afobazole administration restored the cerebral blood supply disturbed by ischemia and increased the stress protein HSP70 synthesis in striatum.

Experiments on immortalized hippocampal cell culture of mice showed that afobazole increases the NGF level in a final concentration of 10(-8) M and the BDNF level in final concentrations from 10(-8) to 10(-5) M.

Cloned bovine embryos were produced at the blastocyst stage. Prior to enucleation, oocytes were freed from the zona pellucida. Fibroblasts isolated from the bovine fetus were used as nuclear donors. Pairs of fetal fibroblasts and enucleated oocytes (cytoplasts) were glued in phytohemagglutinin solution under a binocular microscope. The subsequent electrofusion of 39 fetal fibroblast-cytoplast pairs yielded 36 reconstructed one-cell embryos (92.3%). After culturing in synthetic oviduct fluid for 7.5 days, seven cloned embryos developed to the blastocyst stage (19.4%) and six blastocysts were considered fit for transplantation. The applied technique of bovine embryo growth allowed 31.1% zona-free oocytes parthenogenetically activated by to reach the blastocyst stage.