[Experimental study of the influence of phenozanic acid and its combination with valproic acid on the development of the epileptic system]. / Izuchenie vliyaniya fenozanovoi kisloty i ee kombinatsii s val'proevoi kislotoi na razvitie epilepticheskoi sistemy v eksperimente.

OBJECTIVE: To study the effect of phenosanic acid (PA) and its combination with valproic acid (VA) on the development of the Epi system. MATERIAL AND METHODS: A model of focal chronic epilepsy in rats was created by applying metallic cobalt to the surface of the sensorimotor area of the cortex. Long-term electrodes were implanted in the sensorimotor cortex of the left and right hemispheres, the hippocampus, and the hypothalamus. The effect of PA (80 mg/kg) and its combination with VA (200 mg/kg) on discharge activity was carried out on the 2nd day and at the stage of generalization of the Epi system - on the 6th day. The stability of the Epi system on day 10 was assessed by provoking the development of epileptic status (Epi status) in response to the administration of thiolactone homocysteine (HMC) at a dose of 5.5 mmol/kg. RESULTS: In rats treated with PA, low discharge activity is observed, which is confirmed by the absence of EEG and motor manifestations of status epilepticus caused by HMC. PA does not suppress paroxysmal activity at the stages of development of the Epi system. VA significantly suppresses paroxysmal activity, but does not affect the formation of new foci of Epi activity in subcortical structures and the contralateral cortex. The epi system of rats treated with VA is characterized by high discharge activity by the 10th day of the experiment and lability to provocation of epi status. The combination of drugs is more pronounced than PA, but less than VA, reduces the numerical characteristics of paroxysmal activity in the brain structures of rats. CONCLUSION: PA when administered alone, in combination with VA, causes a slowdown in the generalization of convulsive foci of Epi activity and prevents the formation of a stable Epi system. VA, having a pronounced anticonvulsant effect, does not weaken the development of the Epi system in the model of focal cobalt-induced epilepsy.

[Investigation of the effect of ethylmethylhydroxypyridine succinate on the effectiveness of non-steroidal anti-inflammatory drugs for visceral and somatic pain in mice and rats]. / Izuchenie vliyaniya etilmetilgidroksipiridina suktsinata na effektivnost' nesteroidnykh protivovospalitel'nykh preparatov pri vistseral'noi i somaticheskoi boli v eksperimente na myshakh i krysakh.

OBJECTIVE: To study the effect of ethylmethylhydroxypyridine succinate (EMHPS) on the analgesic effect of the non-selective cyclooxygenase (COX) inhibitor diclofenac sodium and the selective COX-2 inhibitor etoricoxib in models of acute visceral and somatic pain and to evaluate the possibility of using EMHPS in combination with COX inhibitors to reduce their doses while maintaining analgesic efficiency. MATERIAL AND METHODS: We studied the effect of EMHPS with a single oral administration on the analgesic effects of non-steroidal anti-inflammatory drugs (NSAIDs): the non-selective COX inhibitor diclofenac sodium and the selective COX-2 inhibitor etoricoxib - on models of acute visceral (vinegar writhing test) and somatic pain (formalin test and mechanical hyperalgesia during inflammation) in an experiment on mice and rats. RESULTS: In a model of acute visceral pain in mice, EMGPS (25-100 mg/kg) does not have a significant effect on its severity, but enhances the analgesic effect of diclofenac sodium (0.5 mg/kg) and etoricoxib (1 mg/kg). In the formalin test in rats, which simulates pain during surgical incisions (trauma), EMGPS (25 mg/kg) increases the severity of the analgesic effect of COX inhibitors (1 mg/kg), primarily by reducing pain in the acute phase caused by the effect of formalin on afferent neurons. In a model of mechanical hyperalgesia in rats caused by exudative inflammation after injection of a carrageenan solution into the paw, EMHPS enhances the effect of diclofenac to a greater extent than etoricoxib. CONCLUSION: The data obtained indicate the feasibility of a clinical study of the use of EMGPS in combination with NSAIDs for visceral and somatic pain in order to assess its ability to increase the therapeutic effect of NSAIDs.

Specifics of Experimental Modeling 8-OH-DPAT-Induced Perseverative Behavior in Mice.

The effect of 5-HT1A receptor agonist 8-OH-DPAT (intraperitoneal injection in doses of 1, 2, and 4 mg/kg) on spontaneous alternation behavior of mice in Y-maze was studied without and with habituation procedure and food reward. In the first case, 8-OH-DPAT administration led to a decrease in spontaneous alternation and locomotor activity in mice. At the same time, 8-OH-DPAT treatment after habituation and food deprivation increased repeated choices of goal arms without affecting locomotor activity, which was consistent with perseverative behavior. 8-OH-DPAT-induced decrease in spontaneous alternation behavior in Y-maze in mice with habituation and food reward is the most suitable procedure for experimental modeling of the perseverative behavior and studying the anticompulsive activity of new substances.

Experimental Study of Antidepressant Properties of Afobazole.

We studied the effects of oral administration of Afobazole in a dose of 10 mg/kg for 5 days on depressive-like behavior of male C57BL/6 mice in the tail suspension test in comparison with amitriptyline (10 mg/kg) or fluoxetine (20 mg/kg) treatment. Afobazole produced an antidepressant effect similar to amitriptyline, but inferior to fluoxetine. The σ1 receptor antagonist BD-1047 in a dose of 5 mg/kg blocked the antidepressant effect of Afobazole, which indicates the involvement of σ1 receptors in the antidepressant effect of the drug.

Analysis of the Involvement of NMDA Receptors in Analgesia and Hypothermia Induced by the Activation of TRPV1 Ion Channels.

NMDA glutamate receptors play an important role in normal and pathophysiological nociception. At the periphery, they can interact with TRPV1 ion channels. The blockade of TRPV1 ion channels decreases NMDA-induced hyperalgesia, and NMDA receptor antagonists suppress the pain response to the TRPV1 agonist capsaicin. Since TRPV1 ion channels and NMDA receptors can functionally interact at the periphery, it would be interesting to investigate the possibility that they interact in the CNS. A single subcutaneous injection of 1 mg/kg of capsaicin was found to raise the thermal pain threshold in the tail flick test in mice, which reproduces the spinal flexion reflex, owing to the ability of capsaicin to cause long-term desensitization of nociceptors. Preventive administration of either noncompetitive NMDA receptor antagonists (high-affinity MK-801 20 µg/kg and 0.5 mg/kg subcutaneously; low-affinity hemantane 40 mg/kg intraperitoneally) or the selective TRPV1 antagonist BCTC (20 mg/kg intraperitoneally) inhibit the capsaicin-induced increase in the pain threshold. Capsaicin (1 mg/kg, subcutaneous injection) induces transient hypothermia in mice, which is brought about by hypothalamus-triggered vegetative reactions. This effect is prevented by BCTC but not by the noncompetitive NMDA receptor antagonists.

[The role of oxidative stress in hemorrhagic stroke and restorative effects of Mexidol]. / Rol' oksidativnogo stressa pri ostrom eksperimental'nom gemorragicheskom insul'te i terapevticheskie effekty Meksidola.

OBJECTIVE: Identification of the role of oxidative stress in the development of disorders that occur in hemorrhagic stroke (HS, post-traumatic intracerebral hematoma), and the study of the effects of Mexidol on neurological and cognitive deficits in HS with an analysis of the relationship between the therapeutic effects of the drug in HS with its antioxidant effect. MATERIAL AND METHODS: The study was carried out on mature outbred male rats weighing 260-280 g. HS was created by destruction of the brain tissue in the area of the capsula interna, with the introduction of blood into the site of injury. On the 1st, 7th, and 14th days after HS modeling, death, neurological deficits (McGrow scale, rotating rod), convulsive manifestations, and cognitive impairment were recorded in rats; blood plasma and homogenates of the cerebral cortex of rats. Mexidol was administered after the HS operation: first at a dose of 150 mg/kg, intraperitoneally, for 3 days and then 75 mg/kg, orally (from the 4th to the 14th day). RESULTS: Mexidol in rats with HS significantly increases the survival rate of animals, reduces the manifestations of neurological deficits according to the McGrow scale (playpen movements, paresis of 1-4 limbs, paralysis of the lower limbs, lateral position), eliminates individual motor convulsive manifestations, restores impaired coordination of movements (rotating rod test) and improves, impaired HS, learning and memory processes. Mexidol normalizes the concentration of TBA-active products in the blood of animals and homogenates of the cerebral cortex of rats, both a day and 7 days after HS modeling. CONCLUSION: The data obtained indicate the involvement of oxidative stress as a chain of pathogenesis in the development of disorders in HS and the ability of Mexidol to alleviate neurological deficits, convulsive manifestations and cognitive impairment in HS, which is accompanied by a decrease in oxidative stress. All this justifies the importance of the use of Mexidol in patients with hemorrhagic stroke, posttraumatic intracerebral hematoma and determines the features of its therapeutic effects.

[Comparative effect of the prolyl endopeptidase inhibitors, benzyloxycarbonyl-prolyl-prolinal and benzyloxycarbonyl-methionyl-cyanopyrrolidine, on the acute exudative inflammation and visceral pain in mice]. / Sravnenie vliianiia ingibitorov proliléndopeptidazy benziloksikarbonil-prolil-prolinalia i benziloksikarbonil-metionil-tsianopirrolidina na ostroe ékssudativnoe vospalenie i vistseral'nuiu bol' u myshei.

A selective prolyl endopeptidase (PEP) inhibitor benzyloxycarbonyl-prolyl-prolinal (IC50 = 1,61±0,12 nmol/l) and a nonselective PEP inhibitor benzyloxycarbonyl-methionyl-cyanopyrrolidine (IC50 = 2,01±0,14 nmol/l) exhibit a comparable antiexudative effect at single doses of 2 mg/kg and 5 mg/kg (intraperitoneally) in outbred mice with peritonitis induced by 1% acetic acid. However, only benzyloxycarbonyl-methionyl-cyanopyrrolidine at a dose of 5 mg/kg reduces acetic acid induced pain in animals.

Levetiracetam effect on behavioral and electrophysiological parameters in rat model of global brain ischemia.

Post-stroke paroxysmal activity is a neurophysiological indicator of epileptogenesis and increase of seizure susceptibility, so treatments with neuroprotective activity and anti-paroxysmal activity can be more beneficial during post-ischemic period. The goal of this study was evaluation of levetiracetam (100 mg/kg, 7 days of administration) effect on behavior and brain bioelectric activity changes in the post-ischemic period. Global ischemia model was carried out with bilateral ligation of carotid arteries in rats. Neurological deficit and electrophysiological changes of brain structures (striatum, cortex, hypothalamus, hippocampus) were analyzed during 28 days. Paroxysmal activity was not observed on the 1st day after ischemia and had early (2nd day) and late (28th day) onsets. Spectral analysis showed that rats, that died by the 10th day, had delta wave increase and theta decrease on the 1st day and delta activity reduction on the 2-7th days. LEV did not affect survival rate, however, it contributed to neurological disorder regression towards lighter forms on the 1st day after ischemia. It suppressed paroxysmal activity with an early onset and affected delta and theta waves on the 1st day in all structures except hippocampus. On the 7th and 28th days LEV increased delta activity due to 1-3 Hz frequency. Thus, LEV eliminates early onset post-ischemic paroxysmal activity and contributes to normalization of delta waves activity on the 1st day after ischemia, that positively affects neurological status of animals in post-ischemic period. It allows one to make a conclusion about possible LEV application in the post-ischemic period.

[Geroprotective effects of ethylmethylhydroxypyridine succinate in an experimental study]. / Geroprotektivnye effekty etilmetilgidroksipiridina suktsinata v eksperimental'nom issledovanii.

OBJECTIVE: To study an effect of mexidol on the life expectancy, weight, seizure response thresholds, and impaired cognitive and motor functions during aging in male Wistar rats. MATERIAL AND METHODS: In a long-term experiment, male Wistar rats, aged 3-26 months, were assessed for impaired cognitive functions (passive avoidance conditioned reflex test), convulsive threshold (test with pentylenetetrazole), motor deficits (tests of rotating rod and pulling on the crossbar), and life expectancy. The rats received mexidol in the form of 0,15% solution, which replaced drinking water, during two 2 month courses at the age of 18-20 and 22-24 month. A dose of mexidol consumed by the rat was 40-75 mg/kg/day. RESULTS: In old male Wistar rats, the long-term treatment with mexidol increases the life expectancy, improves learning, preservation and reproduction of the memory trace in the passive avoidance conditioned reflex test, increases the convulsive threshold and improves muscle tone and coordination of movements that are impaired during aging. CONCLUSION: Mexidol increases the threshold of convulsive reaction, restores cognitive and neurological deficits that occur during aging in male Wistar rats and increases the by its ability to influence mitochondriogenesis and antioxidant properties.

The Behavioral and Neurochemical Aspects of the Interaction between Antidepressants and Unpredictable Chronic Mild Stress.

The behavioral and neurochemical effects of amitriptyline (10 mg/kg, i.p.) and fluoxetine (20 mg/kg, i.p.) after single and chronic administration in the setting of unpredictable mild stress in outbred ICR (CD-1) mice were studied. After a 28-day exposure to stress, we observed an increase in depressive reaction in a forced swim test in mice, as well as reduced hippocampal levels of serotonin (5-hydroxytryptamine, 5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) and an increased hypothalamic level of noradrenaline (NA). Single and chronic administration of amitriptyline and fluoxetine shortened the immobility period and increased the time corresponding to active swimming in the forced swim test. The antidepressant-like effect of fluoxetine - but not of amitriptyline - after a single injection coincided with an increase in the 5-HT turnover in the hippocampus. Chronic administration of the antidepressants increased the hypothalamic levels of NA. Thus, the antidepressant- like effect of amitriptyline and fluoxetine may result from an enhancement of the stress-dependent adaptive mechanisms depleted by chronic stress.

[Effect of cyanopyrrolidine derivatives on the activity of prolylendopeptidase, acute exudative inflammation and visceral pain in mice]. / Vliianie proizvodnykh tsianopirrolidina na aktivnost' proliléndopeptidazy, ostroe ékssudativnoe vospalenie i vistseral'nuiu bol' u myshei.

Cyanopyrrolidine derivatives benzyloxycarbonyl-methionyl-cyanopyrrolidine (ZMetPrdN), benzyloxycarbonylphenylalanyl- cyanopyrrolidine (ZPhePrdN), tert-butyl-hydroxycarbonyl-glycyl-cyanopyrrolidine (BocGlyPrdN), tert-butyl-hydroxycarbonyl-methionyl-cyanopyrrolidine (BocMetPrdN) are inhibitors of prolylendopeptidase (PREP; EC 3.4.21.26) with an IC50 of 2 nM to 12 nM. ZMetPrdN, ZPhePrdN and BocMetPrdN additionally inhibited dipeptidyl peptidase IV (DPP-4; EC 3.4.14.5) with an IC50 of 1100 nM to 3200 nM. All the compounds have antinociceptive properties in the acetic acid writhing test in mice. But only cyanopyrrolidine derivatives with aromatic substituents decrease exudative inflammation. The cyanopyrrolidine derivatives also increase PREP activity and compensatorily reduce DPP-4 activity in the serum of mice three hours after the induction of inflammation. Thus, cyanopyrrolidine derivatives exhibit antinociceptive and antiexudative properties in part via their effect on PREP.

Antiexudative Effects of Finasteride and a New Pyrazolo[C]Pyridine Derivative GIZh-72 in Acetic Acid-Induced Experimental Peritonitis.

It was shown that finasteride, a 5α-reductase inhibitor (50 mg/kg, intraperitoneally) produced analgesic and antiexudative effects in experimental peritonitis induced by intraperitoneal injection of 1% acetic acid. These results agree with published data on its anti-inflammatory properties and ability to potentiate the analgesic effect of morphine in rodents. New pyrazolo[C] pyridine derivative GIZh-72 (4,6-dimethyl-2-(4-chlorphenyl)-2,3-dihydro-1H-pyrazolo[4,3-C]pyridine-3-on, chloral hydrate) injected intraperitoneally in doses of 20-80 mg/kg produced dose-dependent antiexudative effects, but exhibited no analgesic properties.

Psychotropic Effects of a New Pyrazolo[C]Pyridine Derivate GIZh-72 are Related to Functional Activity of Atp-Sensitive Potassium Channels.

We studied the influence of intraperitoneal injection of ATP-sensitive potassium channels inhibitor glibenclamide in doses of 0.01, 0.1, 1, and 10 mg/kg on the effects of a new pyrazolo[C]pyridine derivative GIZh-72 (4,6-dimethyl-2-(4-chlorphenyl)-2,3-dihydro-1Hpyrazolo[ 4,3-C]pyridine-3-on, chloral hydrate; 20 mg/kg, intraperitoneally) in the marble burying and open-field tests in mice. It was found that glibenclamide produced an anxiolytic effect in the open-field test (in a dose of 0.01 mg/kg) and anticompulsive effect in the marble burying test (in doses of 1 and 10 mg/kg). The observed behavioral effects of glibenclamide did not depend on blood glucose level. At the same time, glibenclamide in subeffective (0.01 and 0.1 mg/kg) and effective (1 and 10 mg/kg) doses potentiated the psychotropic effects of GIZh-72 in these tests. It can be assumed that the psychotropic effects of GIZh-72 depend on functional activity of ATP-sensitive potassium channels.

[The effect of Mexidol on cerebral mitochondriogenesis at a young age and during aging]. / Vliianie Meksidola na tserebral'nyi mitokhondriogenez v molodom vozraste i pri starenii.

AIM: To study the ability of mexidol to induce cerebral mitochondriogenesis in the brain of young and aging rats. MATERIAL AND METHODS: Expression level of marker proteins of cerebral mitochondriogenesis was evaluated during treatment with mexidol (20, 40, 100 mg/kg; 20 days; intraperitoneally) in the cerebral cortex of young (3 month) and aging (6, 9, 12, and 15 month) outbred male rats, using the Western blot analysis. RESULTS: It has been shown for the first time that the course injections of mexidol in doses of 40 and 100 mg/kg is accompanied by dose-dependent induction of the succinate receptor SUCNR1 and protein markers of mitochondrial biogenesis: transcription coactivator PGC-1α, transcription factors (NRF1, TFAM), catalytic subunits of respiratory enzymes (NDUV2, NDUV2,cytb, COX2) and ATP synthase (ATP5A) in the cerebral cortex of young and aging outbred male rats. Mexidol-dependent overexpression of subunits of mitochondrial enzymes and PGC-1α is observed only with the course of the drug. CONCLUSION: The results indicate the ability of mexidol to induce cerebral mitochondriogenesis and eliminate mitochondrial dysfunction in young and aging animals and, thus, exert an effect on one of the key pathogenetic links of the development of disorders in aging and neurodegenerative diseases.

Role of GABAA Receptors in the Mechanism of In Vivo Psychotropic Activity of Amitriptyline in Rats.

Standard water-reinforced drug discrimination model was employed to train Wistar rats to discriminate the intraperitoneal injections of tricyclic antidepressant amitriptyline (5.4 mg/kg) and physiological saline. To examine the role of GABAA receptors in psychotropic action of amitriptyline, the substitution tests were performed with muscimol (0.1-1.0 mg/kg) and pregnenolone (30-50 mg/kg). Similar tests were carried out with amitriptyline interoceptive antagonists bicuculline (1 mg/kg), flumazenil (15 mg/kg), finasteride (5 mg/kg), and indomethacin (7.5 mg/kg). The study showed that interoceptive effects of amitriptyline depend on functional activity of GABAA receptors but not on the neurosteroid site of GABAA receptor complex.

Neuroprotective and Antiamnestic Effects of a New Drug Emopag in Rats.

Emopag, a new drug, preventively administered in doses of 10 and 30 mg/kg/day over 4 days produced a pronounced neuroprotective effect in the model of brain ischemia caused by gravitational overload and reduced animal mortality from 17 to 0%. The preparation more effectively corrected neurological deficit than the reference drugs Mexidol (in considerably larger doses of 30 and 90 mg/kg/day) and antihypoxic drug amtizol (30 mg/kg/day). Moreover, Emopag exhibited considerable antiamnestic activity comparable to that of Mexidol (in 3-fold higher doses); in a dose of 30 mg/kg/day Emopag was more effective than Mexidol and amtizol in the same dose. Thus, Emopag showed marked neuroprotective and antiamnestic effects in the model of gravitational overload in rats.

Afobazole Alleviates Cognitive Rigidity in Experimental Model of Autism Spectrum Disorders.

Afobazole (10 mg/kg) alleviated cognitive rigidity in BALB/c mice, a phenotypic model of autism spectrum disorders. It improved spatial memory and retraining in T-maze with drinking reinforcement and restored the retrieval of acquired skill during reversal learning in Morris water maze.

[Combined administration of mexidol with known medicines]. / Kombinirovannoe primenenie meksidola s izvestnymi lekarstvennymi sredstvami.

This review summarizes the available data on the combined administration of mexidol with medicines of different pharmacotherapeutic groups. Mexidol has a multifaceted mechanism of action and exhibits a wide range of pharmacological effects. It enhances therapeutic effects of a variety of drugs in research and clinical settings, boosts the effectiveness of therapy prescribed in accordance with the applicable federal standards and contributes to reducing the severity of complications. Effectiveness data and pathogenetic considerations underpinning combination therapy with mexidol and other drugs suggest that this is a viable approach for treating cerebrovascular and cardiovascular diseases, diseases of the nervous system, open-angle glaucoma and alcohol intoxication as well as a number of other diseases.

[Effect of afobazole and levodopa on the activity of proline-specific proteinases and adenosine deaminase in blood serum and brain structures of rats with experimental Parkinson's syndrome induced by systemic administration of rotenone]. / Vliianie afobazola i levodopy na aktivnost' prolinspetsificheskikh proteinaz i adenozindezaminazy v syvorotke krovi i strukturakh golovnogo mozga krys s éksperimental'nym parkinsonicheskim sindromom, vyzvannym sistemnym vvedeniem rotenona.

Rats with experimental Parkinson's syndrome induced by seven-day intraperitoneal administration of rotenone at a dose of 2.75 mg/kg have an increased activity of prolylendopeptidase (EC 3.4.21.26, PREP) in blood serum and a decreased activity of adenosine deaminase (EC 3.5.4.4, ADA) in serum and in the prefrontal cortex. PREP and ADA activity in other brain structures (in the striatum, hypothalamus and hippocampus) did not change; dipeptidyl peptidase IV activity (EC 3.4.14.5, DPP-4, CD26) also remained constant in serum and in all the brain structures investigated. Afobazole and levodopa, which exhibit antiparkinsonian activity in this model of Parkinson's syndrome, decrease elevated PREP activity in serum and increase reduced ADA activity in the prefrontal cortex of rats with the experimental pathology. Meanwhile, treatment with the study drugs was associated with a decrease of ADA activity in the other brain structures.

Activities of Proline-Specific Proteinases in the Serum and Cerebrospinal Fluid of Rats with the Fetal Valproate Syndrome.

In 60-day-old Wistar rats with fetal valproate syndrome, the brain to body weight ratio was higher by 9.4% and activity of dipeptidyl peptidase IV in the serum and cerebrospinal fluid was higher by 18.4 and 40.6%, respectively, than in healthy controls. Activity of prolylendopeptidase in the serum and cerebrospinal fluid in rats with the fetal valproate syndrome did not differ from the control.