[Hypocoagulant effect of the novel dipeptide NGF mimetic GK-2].

The effect of an original dimeric dipeptide NGF mimetic, GK-2 (hexamethylenediamide bis-N-monosuccinyl-L-glutamyl-L-lysine, designed on the basis of the beta-turn of the 4th NGF loop) on the hemostasis and fibrinolysis was studied in intact and diabetic Wistar rats in various periods of disorder development. Model diabetes was induced by single streptozotocin (40 mg/kg i.p.

[The study of procognitive effect of the potential antipsychotic, Dilept and its main metabolite, GZR-125 at the novel objects recognition test in rats].

The effect of dipeptidal neurotensine mimetic, N-caproyl-L-prolyl-L-tyrosine methyl ester (GZR-123, Dilept) and its main metabolite N-caproyl-L-prolyl-L-tyrosine (GZR-125) was evaluated at novel objects recognition test (NOR) in the male outbred rats. NOR was chosen from many cognitive test as those involving the selective action on the attention and episodic memory and considering as translational model for the study of cognition deficiency in schizophrenics. M-cholinoblocking agent scopolamine (0.

[The efficacy of human NGF dipeptide mimetic on the streptozotocin-induced model of diabetes in rats].

The effect of a new dimeric dipeptide mimetic GK-2 of the loop-4 human NGF (hexamethylendiamide-bis-N-monosuccinyl-glycil-L-lysine) was investigated for the first time on the dynamics of hyperglycemia and body weight loss caused in Wistar rats by streptozotocin (45 mg/kg i.p.) Prophylactic (2 weeks before streptozotocin) daily administration combined with therapeutic (4 weeks after STZ) administration of GK-2 (0.

[Neuroprotective effects of a dipeptide mimetic on the GK-2 nerve growth factor in model of permanent common carotid artery occlusion in rats].

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 search of small molecules with antipsychotic activity on the background of neurotensin].

Tridecapeptide neurotensin (NT) is known to exert the neuroleptic-like effects in case of its intracerebral administration. The group of systemically active dipeptides , acylprolyltyrosines, was constructed on the background of NT. Methyl ester of N-caproyl-L-prolyl-L-tyrosine (Dilept) was chosen for further development.

[Effect of dipeptide neurotensin analog dilept on extracellular concentrations of glutamate, GABA and HVA in N. accumbens of rat brain].

The influence of dilept (GZR-123, N-caproyl-L-prolyl-L-tyrosine methyl ester)--a dipeptide analog of neurotensin (NT)--on extracellular concentration of glutamate, gamma-aminobutyric acid (GABA) and homovanillic acid (HVA) in n. accumbens of Wistar rats has been studied. By means of microdialysis, it was shown that dilept increases the concentrations of glutamate and GABA and decreases the HVA content in n.

[On the mechanism of noopept action: decrease in activity of stress-induced kinases and increase in expression of neutrophines].

The influence of noopept (N-phenylacetyl-L-prolylglycine ethyl ester, GVS-111)--a drug combining the nootrope and neuroprotector properties--on the activity of mitogen-activated protein kinases (MAPKs) and the level of NGF and BDNF gene and protein expression in the frontal cortex, hippocampus, and hypothalamus has been studied in rats. Under conditions of chronic administration (28 days, 0.5 mg/day, i.

[Effect of the novel nootropic and neuroprotective dipeptide noopept on the streptozotocin-induced model of sporadic Alzheimer disease in rats].

Streptozotocin-intracerebroventricularly treated rats are proposed as an experimental model of sporadic Alzheimer disease (AD). Diabetogenic toxin streptozotocin (STZ) administered in both cerebral ventricles in a dose of 3 mg/kg decreases the expression of NGF and BDNF mainly in the hippocampus and increases the content of malonic dialdehyde (MDA)--a product of lipid peroxidation--in the brain tissues. These metabolic changes are accompanied by a pronounced cognitive deficiency, which is manifested by long-term memory deterioration in the passive avoidance test.

[The original nootropic and neuroprotective drug noopept potentiates the anticonvulsant activity of valproate in mice].

The influence of the original dipeptide drug noopept, known to possess nootrope, neuroprotector, and anxiolytic properties, on the anticonvulsant activity of the antiepileptic drug valproate has been studied on the model of corazole-induced convulsions in mice. Neither a single administration of noopept (0.5 mg/kg, i.

[Neurotensine dipeptide analog dilept decreases the deficiency of prestimulus startle reflex inhibition: a prognostic sign of antipsychotic activity].

The antipsychotic properties of dilept, a new drug representing substituted dipeptide based on a beta-rotational structure of the main metabolite of endogenous neuroleptic NT8-13, have been studied using the test for prestimulus inhibition (PSI) of the acoustic startle reflex in rats. It is established that dilept eliminates the PSI deficiency caused by the introduction of a noncompetitive NMDA receptor blocker ketamine, which is evidence for pronounced neuroleptic properties of the drug. Effective doses of dilept for intraperitoneal administration were 1.

[Experimental pharmacokinetics of the new neurotensine-derived antipsychotic drug dilept].

The metabolism and pharmacokinetics of a new neurotensine-derived dipeptide drug dilept (N-caproyl-L-prolyltyrosine methyl ester) and its tentative metabolites after intravenous and peroral administration of the parent drug and its tabletized form in rats have been studied by HPLC-ESI(-)-MS/MS method. It is established that unchanged dilept (detected in the blood plasma for no less than 30 min) as well as N-caproyl-L-proline and N-caproyl-L-prolyl-L-tyrosine (both detected in the blood over more than 4 h) are the major metabolites in the bloodstream upon peroral administration of the drug. The proposed structures of metabolites were confirmed by countersynthesis.

[Interstrain differences in the content of excitatory and inhibitory amino acids in the brain of DBA/2J, Balb/c and C57BL/6 mice: characteristics of the effect of a dipeptide antipsychotic drug dilept].

We have performed a comparative study of the content of glutamate (Glu), aspartate (Asp), taurine (Tau), glycine (Gly) and gamma-amino-butyric acid (GABA) in the cortex, hippocampus, and striatum of the DBA/2J, Balb/c and C57BL/6 mice brain. The levels of Glu, Tau and GABA in DBA/2J hippocampus was lower than those in other experimental strains. These findings are consistent with published data on the specific neurophysiological properties of DBA/2J (neuroleptic sensitive prepulse inhibition, deficit), thus allowing this strain to be used in modeling schizophrenia.

[Genotype-dependent mice behavior in cognitive tasks. Effect of noopept].

The interstrain differences in performance of C57BL/6J, BALB/c and DBA/2J male mice in two cognitive tasks were found. Mice C57BL/6J showed good learning ability and preservation of memory traces tested 10 days after performance in a simplified version of Morris water maze. Mice BALB/c learned the task but, virtually, no long-term memory traces were revealed, whereas DBA/2J demonstrated poor learning.

[Behavior of mice from different strains: modifications produced by noopept].

Genotype-dependent behavioral effects were demonstrated in BALB/c, C57BL/6J [Russian character: see text] DBA/2J mice after injections of nootropic drug Noopept. In an elevated plus maze, drug administration induced an increase in the number of enterings into bright arms in BALB/c mice, whereas the opposite effect was observed in C57BL/6J. After the Noopept administration, animals from all the three strains increased the number of active avoidance reactions in stress-inducing slip-funnel test.

[Decrease in the glutamate release may contribute to the neuroprotective action of the novel neuroleptic drug dilept].

Dilept (GZR-123, N-caproyl-L-prolyl-L-tyrosine methyl ester), designed and synthesized at the Zakusov Institute of Pharmacology, was chosen as one of the most effective compounds from a series of N-acylprolyltyrosine derivatives having common pharmacophores with beta-turn of neurotensin (NT(8-13)) and repeating the structure of a nonpeptide prototype, the atypical neuroleptic sulpiride. The aim of this study was to evaluate the effect of dilept on the level of spontaneous and K(+)-stimulated release of glutamate. The experiments were performed in vitro on the cortical brain slices of male Wistar rats.

[Analysis of passive avoidance learning in a modified three-compartment setup].

Passive avoidance conditioning is analyzed in a three-compartment apparatus comprising the central light compartment, the dark dangerous compartment in which the electric foot shock was delivered, and the dark safe compartment where the rats were not punished. The passive avoidance performance was characterized, in addition to the latent period duration, by the number of visits into the safe compartment. The experimental data indicate that the latency of the passive avoidance response and the safe compartment preference obey different laws.

[Neuroprotective activity of the proline-containing dipeptide noopept on the model of brain ischemia induced by the middle cerebral artery occlusion].

The influence of noopept (N-phenylacetyl-L-prolylglycine ethyl ester, GVS-111) on the extent of ischemic cortical stroke was investigated in experiments on white mongrel male rats with ischemia induced by a combination of the middle cerebral artery occlusion with ipsilateral common carotid artery ligation. Animals were treated with noopept (0.5 mg/kg, i.

[The new tripeptoid neurotensin analog dilept selectively affects dopamine turnover in nucleus accumbens and hypothalamus].

The effects of dilept (N-caproyl-L-prolyl-L-tyrosine methyl ester) - a new peptidomimetic of neurotensine - on the level of monoamines and their main metabolites in four functionally important brain structures has been studied upon single and subchronic administration in intact rats and in those pretreated with the NMDA receptor blocker ketamine. Repeated administration of dilept favors the accumulation of DOPAC and accelerates the dopamine (DA) turnover in nucleus accumbens, as manifested by an increase in the DOPAC/DA ratio. The opposite effect (decrease in the DOPAC/DA ratio) was observed in the hypothalamus, where the subchronic treatment with dilept completely inhibited the activating action of ketamine on the DA turnover.

[Noopept improves the spatial memory and stimulates prefibrillar beta-amyloid(25-35) antibody production in mice].

The effects of the novel proline-containing nootropic and neuroprotective dipeptide noopept (GVS-111, N-phenylacetyl-L-prolylglycine ethyl ester) were studied on NMRI mice upon olfactory bulbectomy, which had been previously shown to imitate the main morphological and biochemical signs of Alzheimer's disease (AD). The spatial memory was assessed using the Morris (water maze) test; the immunological status was characterized by ELISA with antibodies to prefibrillar beta-amyloid(25-35), S100b protein, and protofilaments of equine lysozyme, which are the molecular factors involved in the pathogenesis of AD. The control (sham-operated) animals during the Morris test preferred a sector where the safety platform was placed during the learning session.

[Dilept: a tripeptoid neurotensin analog combining neuroleptic activity with positive mnemotropic action].

The effect of N-caproyl-L-prolyl-L-tyrosine methyl ester (GZR-123, Dilept), a new antipsychotic drug with a dipeptide structure, on cognitive functions was studied using the passive avoidance conditioned reflex (PACR) test. It was found that the drug improved both the acquisition and retrieval of PACR under the conditions of undertraining and prevented the amnesic effect of transcorneal electroshock. The neurotransmitter analysis of these effects using the corresponding blockers showed the ability of dilept to facilitate the central glutamatergic (NMDA type) and cholinergic (of both muscarine and nicotine types) neurotransmission.

[Interspecies differences of noopept pharmacokinetics].

Significant interspecific differences in the pharmacokinetics of noopept are manifested by a decrease in the drug elimination rate on the passage from rats to rabbits and humans. Very intensive metabolism of noopept was observed upon intravenous administration in rats. In these animals, presystemic elimination mechanisms lead to the formation of a specific metabolite representing a product of drug biotransformation hydroxylated at the phenyl ring.

[Evolution of the neuroprotection concept].

Although the modern concept of neuroprotection has been formulated quite recently, the basis of this approach was laid about four decades ago when Zakusov initiated the study of mechanisms involved in the neuroprotector action of GABA shunt metabolites (in particular, alpha-hydroxybutyric acid and succinic semialdehyde) during hypoxia. It was suggested to consider these agents as a system of endogenous neuroprotectors. The interest of Zakusov in endogenous regulators (including oligopeptides) had stimulated research in this direction and gave impact to the investigations of A.

[The original novel nootropic and neuroprotective agent noopept].

The paper describes pharmacological properties of the new nootropic drug noopept created using an original approach based on the imitation of a nonpeptide nootrope structure by means of the short-peptide design. In particular, the structure of pyracetam was designed using dipeptide nootropes. Experimental investigations of noopept (N-phenylacetyl-L-polyglycine ethyl ester) showed that the new drug exceeds pyracetam both with respect to the effective dose level (1000 times lower for noopept than for pyracetam) and in the spectrum of mnemotropic activity.

[Anti-inflammatory properties of noopept (dipeptide nootropic agent GVS-111)].

It is established that single intravenous (0.5 and 5 mg/kg, p.o.

[Multicomponent antithrombotic effect of the neuroprotective prolyl dipeptide GVS-111 and its major metabolite cyclo-L-prolylglycine].

The experiments in vivo showed that the new nootropic prolyl-containing GVS-111 produces an antithrombotic effect, influencing various stages of the blood coagulation process. GVS-111 exhibits anticoagulant and fibrinolytic properties and enhances fibrin destabilization by reducing the XIIIa factor activity. These effects are manifested upon both intraperitoneal (1 mg/kg) and peroral (10 mg/kg) administration of GVS-111 (in both cases, a single daily treatment over a period of 10 days).