Chronic Ethanol Consumption by Rats before Mating Affects Working Memory in the Offspring.

Parameters of non-spatial and spatial memory were evaluated in sexually mature offspring of outbred rats (females and males F0) consuming a 10% ethanol solution for 30 weeks before mating. We found a significant increase in the recognition index in F1 males and its decrease in F1 females in the novel object recognition test. During the first days of the experiment in T-maze, a decrease in spatial memory was revealed in F1 males, which remained at the trend level until the end of testing; no significant deviations were detected in F1 females. Memory impairment in F1 females was accompanied by a decrease in BDNF level in the hippocampus, but not in the prefrontal cortex. Thus, ethanol consumption by F0 rats before mating led to impairment of long-term working memory only in female F1 offspring.

Pharmacogenetic Analysis of the Interaction of the Low-Molecular-Weight BDNF Mimetic Dipeptide GSB-106 with TRK Receptors.

Using TrkA or TrkB receptor gene knockout HT-22 cells, the selectivity of the interaction of the low-molecular-weight dipeptide BDNF mimetic GSB-106 (hexamethylenediamide bis(N-monosuccinyl-L-seryl-L-lysine)) with TrkB receptors was shown.

The First Dipeptide Mimetic of Neurotrofin-3: Design and Pharmacological Properties.

The dimeric dipeptide mimetic hexamethylenediamide bis-(N-monosuccinyl-L-asparaginyl-L-asparagine) (GTS-301) was created on the basis of the structure of the exposed region of the neurotrophin-3 4th loop. The new compound, as well as the full-length neurotrophin, activated the TrkC and TrkB receptors. GTS-301 showed neuroprotective activity in experiments on HT-22 mouse hippocampal cells under conditions of oxidative stress and glutamate toxicity at concentrations of 10-12 and 10-8 M, respectively, and antidepressant-like activity in the forced swimming test on mice with 7-day intraperitoneal administration in doses of 10-40 mg/kg.

Dipeptide Mimetics of Different NGF and BDNF Loops Activate PLC-γ1.

Previously, we designed and synthesized dipeptide mimetics of individual loops of the nerve growth factor (NGF) and the brain-derived neurotrophic factor (BDNF). It was shown that these mimetics activate the corresponding tyrosine kinase (Trk) receptors and have different patterns of activation of the PI3K/AKT and MAPK/ERK postreceptor signaling pathways in vitro. In the present study, it was shown on HT-22 cells that all these compounds activate the phospholipase C-γ1 (PLC-γ1) cascade.

[COMPARISON OF CYTOPROTECTIVE EFFECTS OF HEMANTANE AND AMANTADINE UNDER CONDITIONS OF 6-HYDROXYDOPAMINE NEUROTOXIN ACTION ON CULTURED HUMAN NEUROBLASTOMA CELLS].

Potential neuroprotective activity of the novel antiparkinsonian drug hemantane (hydrochloride N-2-(adamantyl)-hexamethylenimine) in comparison to amantadine has been studied in various regimes of administration on human neuroblastoma SH-SY5Y cell line injury induced by 6-hydroxydopamine (6-OHDA), which is used as in vitro model of dopaminergic neurons for Parkinson's disease. Two regimes of hemantane and amantadine administration in a range of final concentrations 10⁻6-10⁻8 M were used either prior to or immediately after 6-OHDA introduction. MTT colorimetric assay was used to assess the viability of test cells. Significant decrease in viability of SH-SY5Y cells treated with 6-OHDA was observed. The addition of hemantane to cell medium produced cytoprotective effects in both regimes of administration--before and after 6-OHDA--at concentrations 10⁻7 M and 10⁻6-10⁻8 M, respectively. Amantadine in con- centrations 10⁻7-10⁻8 M was effective to increase cell survival only when administered after 6-OHDA. These results show that hemantane has a greater neu-roprotective potential in comparison to amantadine.

Neuroprotective and Antioxidant Effects of Neuroglutam in Cerebral Ischemia.

We studied in vitro and in vivo neuroprotective and antioxidant properties of neuroglutam, a new glutamic acid derivative. In experiments on immortalized mouse hippocampal cell line HT22, neuroglutam exhibited a neuroprotective effect in the model of oxidative stress after its introduction, both before and after H2O2. In vivo study on animals treated with neuroglutam against the background of cerebral ischemia modeled by irreversible occlusion of the common carotid arteries showed that plasma level of TBA-active products was significantly lower and activities of cell antioxidant enzymes (superoxide dismutase and catalase) were higher than in control animals receiving saline under the same conditions.

[Neuroprotective effect of neuroglutam under conditions of activated free radical oxidation].

The neuroprotective properties of the novel glutamic acid derivative neiroglutam have been studied in vitro and in vivo. Neiroglutam demonstrated the protective action on 6-OH-dopamine neurotoxicity model in vitro, where free radical oxidation is a basic part of pathogenesis. In control rats, focal brain ischemia caused significant increase in thiobarbituric acid reactive species (TBARS) level and decrease in superoxide dismutase (SOD) enzyme activity. In two-year-old rats, preventive administration of the neiroglutam caused a significant reduction in the TBARS plasma concentration (34.5%, p < 0.05), increased SOD activity, and increased the time of acid-induced hemolysis of erythrocytes (40%, p < 0.05).

[Study of structure-activity relationship in series of Gsb-106 analogues-dipeptide mimetics of brain-derived neurotrophic factor].

In previous work we have obtained a dimeric dipeptide mimetic of 4th loop of BDNF - hexamethylenediamide bis-(N-monosuccinil-L-seryl-L-lysine) (GSB-106), having a neuroprotective activity in vitro in a concentration range 10(-5)-10(-8) M and an antidepressant activity in vivo at doses 0.1 and 1 mg/kg i.p. in rats. We have investigated the structural and functional relationships among analogues of GSB-106. Glycine scan was performed and a number of appropriate compounds were synthesized: GT-105 (here lysine is replaced by glycine), GT-107 (here serine is replaced by glycine), GT-106Ac (here monosuccinic radical is replaced by acetyl group). We have studied the dependence of activity of following compounds from the configuration of amino acid residues: GT-107D (D-enantiomer of the GT-107), GT-106DL (L-serine was replaced by D-serine), GT-106LD (L-lysine was replaced by D-lysine). The investigation of these compounds using the HT22 cell culture in conditions of oxidative stress has approved only two analogues of GSB-106 to have a neuroprotective effect: in the case of replacement of serine to glycine and of replacment of succinic radical to acetic group. A disappearance of this effect was observed in event of the replacement of lysine residue to glycine in GT-105, L-lysine residue to D-lysine and also by conversion of serine configuration. These results show that lysine residue is crucial for the neuroprotective activity of GSB-106. L-Configuration of the lysine and serine residues required. Configuration of lysine residue becomes critical in absence of serine side group. Thus, the the following fragment is a minimum pharmacophore of beta-turn of 4 loop of BDNF: HOOC-CH2-CH-CO-NH-(S)-CH(CH2OH)-CO-NH-(S)-CH((CH2)4NHz)-CO-NH-(CH2)3-. Only one (GT-106Ac) out of two analogues of GSB-106 with neuroprotective activity possesses antidepressant activity too. This fact indicates about a necessity of more stringent structural requirements for exposure of antidepressant activity. The results obtained can be useful for designing of new active mimetics of BDNE

Neuroprotective effects of dipeptide analogue of brain-derived neurotrophic factor GSB-106 in in vitro experiments.

Dimeric dipeptide GSB-106, a novel structural analogue of neurotrophin BDNF, in doses from 10(-5) to 10(-8) M protected cultured immortalized mouse hippocampal HT-22 neurons from H2O2 or glutamate damage. The neuroprotective effect of GSB-106 was also shown on cultured SH-SY5Y human neuroblastoma cells after treatment with neurotoxin 6-hydroxidopamine. These data attest to functional similarity of GSB-106 and neurotrophin BDNF.

[Design and synthesis of dipeptide mimetics of brain-derived neurotrophic factor].

Low-molecular mimetics of brain-derived neurotrophic factor (BDNF) loops 1 and 4 representing to monomeric and dimeric amides of N-acyldipeptides were constructed and synthesized. The sequence of these dipeptides coinside with the central regions of beta-turns of corresponding loops of neurotrophine sequence, and acyl groups are bioisosters of preceding amino acid residues. Hexa- and heptamethylenediamine were used as spacers linking C-terminus ofdipeptides in BDNF dimeric mimetics. These substances were synthesized by classic peptide synthesis methods in solution and got laboratory codes GSB-104 (HO-Suc-Ser-Lys-NH2), GSB-106 ([HO-Suc-Ser-Lys-NH-(CH2)3-]2), GSB-207 (HO-Suc-Met-Ser-NH2) and GSB-214 ([HO-Suc-Met-Ser-NH-(CH2)7/2-]2). By using the culture of immortalized hippocampal cell line HT-22 on the oxidative stress conditions it was shown that dimeric mimetics of both loops demonstrated neuroprotective activity in the concentration rage of 10(-5)-10(-8) M. Monomeric loop 1 mimetic GSB-207 was inactive in the same concentrations and monomeric loop 4 mimetic GSB-104 in a concentration of 10(-7) M decreased survival of neurons. Presence of neuroprotective activity only for dimeric mimetics correlates with the data that BDNF is active only in homodimeric form. As opposed to dimeric mimetic of loop 1 GSB-214, dimeric mimetic of loop 4 GSB-106 demonstrates specific for BDNF antidepressive activity in Porsolt test on rats in doses 0.1 and 1 mg/kg i.p. It is suggested that antidepressive activity of BDNF is associated with its loop 4. We consider that compounds obtained will be useful for investigation of BDNF action mechanism and can lead to creation of a new group of medicinal substances with antidepressive and neuroprotective activities.

[A comparative study of hemantane and amantadine effects on dopamine transporter expression in brain of normal and MPTP-treated C57BL/6 mice].

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.

[Effects of afobazole on the stress protein HSP70 level in the brain tissue of rats with global transient ischemia].

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.