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Biomedical subjects

A A Shandra

Publications and source records attributed to A A Shandra.

At least 55 records · Page 3Linked to original sources
PubMed1988

[The effect of delta sleep-inducing peptide on the convulsive activity in corasol kindling].

The influence of intraperitoneal delta-sleep inducing peptide (DSIP) injection (100 micrograms/kg) on the epileptic activity was investigated in the experiments on Wistar rats and (CBA X C57B1/6)F1 mice. The model of chronically developing epileptic activity--the model of pharmacological kindling--was created by daily repeated corasole injections in subconvulsive doses (30 mg/kg). It has been shown that DSIP injection delayed the manifestation of generalized seizures during kindling, led to the suppression of seizure activity and reduced the mortality rate of animals that developed kindled seizures. The antiepileptic effect of DSIP was observed throughout the period of 5 minutes to 24 hours after the injection. Naloxone (2.5 mg/kg) did not change the antiepileptic effect of DSIP.

Animals↗
PubMed1987

[Modelling of the parkinsonian syndrome by the administration of kainic acid into the caudate nucleus].

The experiments on rats have shown that bilateral administration of kainic acid (0.1-0.15 microgram) into the rostral parts of caudate nuclei led to the development of hypokinesia and rigidity. An increase in the electrical activity--the formation of the generator of pathologically increased excitement (GPIE) was noted in a zone of kainic acid injection. Rigidity and hypokinesia were attenuated and the GPIE activity was depressed after cyclodol (1-10 mg/kg) or L-DOPA (100-200 mg/kg) administration. Combined administration of cyclodol (2 mg/kg) and L-DOPA (50 mg/kg) induced potentiated antiparkinsonian effect. Dopamine microinjections into the GPIE area depressed its activity and abolished rigidity and hypokinesia. These data suggest that the Parkinson syndrome develops under the influence of GPIE induced by kainic acid administration into caudate nuclei.

Animals↗
PubMed1987

[Effect of the delta sleep peptide on epileptic activity in the cerebral cortex of rats and cats].

In free behaviour experiments on rats it has been shown that the intraperitoneal injection of delta sleep-inducing peptide (DSIP) (100 micrograms/kg) suppressed penicillin-induced relatively moderate epileptic foci which generated spike potentials as well as severe foci with ictal epileptic discharges. In the experiments on cats it was shown that intravenous DSIP injection (100 micrograms/kg) suppressed strychnine-induced epileptic focus and complexes of epileptic foci.

Animals↗
PubMed1987

[Changes of the dehydrogenase activity in the hippocampus in the korazol-induced kindling phenomenon].

The activity of glutamate, succinate, malate and lactate dehydrogenases in neuronal and glial hippocampal cells during corazol kindling has been cytophotometrically assessed in the experiments on (CBA X C57BL/6)F1 mice. The kindling was induced by regular intraperitoneal corazol injections in subliminal dose of 30 mg/kg. Histochemical investigations were performed 30 min, 24 hours and 30 days after the corazol injections were discontinued. The changes in the enzymatic activity revealed suggest the biphasic nature of the disturbances in energy metabolism. During the first phase (24 hours after the last injection) the enzymatic changes do not have a noticeable influence on the predominant aerobic type of oxidation. In the second phase (30 days after the last injection) lactate dehydrogenase activity significantly increases, while the activity of other enzymes under study reduces.

Animals↗
PubMed1986

[Changes in the dehydrogenase and GABA transaminase activity in the cerebral cortex during corazol kindling].

The experiments on (CBA X C57BL/6)F1 mice have shown that regular corazol injections in subliminal doses stimulated seizure susceptibility (pharmacological kindling). Cytophotometric assay of the activity of oxidative metabolism enzymes (glutamate dehydrogenase, malate dehydrogenase, succinate dehydrogenase, alpha-oxoglutarate dehydrogenase, lactate dehydrogenase) and GABA-transaminase in the sensorimotor cortex of kindled mice in post-convulsive period, and 24 hours or 30 days after corazol injections were discontinued, has revealed some specific alterations of the enzymes under study, that suggest the existence of two phases of energy metabolism disturbances. The first phase (24 hours after corazol injections were discontinued) is characterized by intensified succinic acid oxidation, while the second phase (30 days after the last injection) is characterized by anaerobic glycolysis in neuronal and glial cells. Inhibition of GABA-transaminase activity was particularly marked in postconvulsive period. From a molecular point of view these data may be considered as enzyme disturbances during stimulation of seizure susceptability or seizure activity and as a compensation component ensuring anticonvulsive mechanisms and reparative processes (antagonistic principle of molecular mechanism regulation) during activation of antiepileptic system.

4-Aminobutyrate Transaminase↗
PubMed1985

[Effect of diazepam, carbamazepine, sodium valproate and their combinations with vitamin preparations on epileptic activity].

The anticonvulsive action of diazepam, carbamazepine, sodium valproate and their combinations with pyridoxal-5-phosphate, nicotinamide, and alpha-tocopherol were investigated in acute experiments on mice with corazole-induced seizures. Diazepam (0.5 mg/kg), carbamazepine (50 mg/kg) and sodium valproate (200 mg/kg) were shown to reduce convulsive intensity and lethality. Vitamins nicotinamide (250 mg/kg), pyridoxal-5-phosphate (10 mg/kg) and alpha-tocopherol (100 mg/kg) potentiated anticonvulsive action of the above antiepileptic drugs. The results of the investigation suggest the efficacy of pathogenetic therapy and give new evidence of the advisability of using vitamins in combination with synthetic anticonvulsive drugs.

Animals↗
PubMed1985

[The hippocampus as the determinant structure generating epileptic activity during korazol kindling].

It has been shown in chronic experiments on rats that two periods of EEG and behavioral alterations may be distinguished during korazol kindling. The bursts of slow waves and spike-wave activity appear on the EEG during the first period as response to subthreshold doses of korazol, which is accompanied behaviorally by standing and myoclonuses. The second period is characterized by the appearance of high-frequency polymorphous generalized seizure discharges on the EEG accompanied by clonicotonic seizures. Interictal and ictal epileptic discharges appear primarily in the hippocamp and then in other brain structures during the development of korazol kindling. The conclusion is made that the hippocamp plays the role of a pathological determinant structure in the development of chronic brain epileptization during korazol kindling.

Animals↗
PubMed1985

[Characteristics of the electrical activity in hippocampal slices in mice with Corazol kindling].

It has been shown in experiments on hippocampal slices of (CBA X C57BL/6)F1 mice with corazol kindling that the threshold of the appearance of the induced seizure discharge (ISD) in the area CA1 was decreased by stimulation of Schaffer collaterals. Diazepam provoked an increase in seizure susceptibility to corazol and penicillin and reduction of the ISD. The data suggest that alterations in neuronal reactivity, which follow kindling, can be found in an individual hippocampal segment, thus making it possible to investigate this phenomenon at the synaptic and molecular levels.

Animals↗
PubMed1985

[Effect of destruction of the hippocampus and caudate nucleus on the development of epileptic activity during corazole kindling].

Experiments were carried out on random-bred white rats (250-350 g). Kindling was induced by daily intraperitoneal corazol injections in subthreshold (subconvulsive) doses (30 mg/kg). It has been demonstrated that bilateral hippocampal destruction did not change the seizure threshold, while bilateral caudate nucleus destruction lowered it. Hippocampal destruction delayed corazol kindling development and also accelerated the lowering of seizure susceptibility after corazol injections were discontinued, as compared to control animals. Caudate nucleus destruction induced more marked seizure reactions in the first 14 days after corazol injections were started. There were no significant differences in seizure manifestation severity in kindled and control groups. These data point to an essential role of caudate nucleus as an element of antiepileptic system and support the concept that hippocampus plays a role of pathologic determinant which is associated with the formation of an epileptic system underlying corazol kindling.

Animals↗
PubMed1984

[Antiepileptic effects of synthetic pharmacologic agents and vitamin preparations used in combination].

The effects of synthetic antiepileptic drugs (phenobarbital and diazepam) and vitamins (nicotinamide, pyridoxal-5 phosphate and alpha-tocopherol) were investigated on the model of the chronically epileptized brain in the form of corasole kindling in inbred and noninbred mice. It has been shown that both series of drugs inhibit the epileptic activity developing at the peak of brain epileptization and prevent its further development. The results of the study demonstrate the benefit of the multimodality pathogenetic therapy of epilepsy and suggest the advisability of its practical application.

Animals↗
PubMed1984

[Effect of vitamin preparations on epileptic activity].

It has been shown in experiments on mice and rats that daily administration of subthreshold doses of pentylenetetrazol led to a progressive increase in the sensitivity to the action of the epileptogen, augmentation of brain epileptization and development of the pharmacological kindling. Single administration of nicotinamide in doses of 250, 500 and 1000 mg/kg and alpha-tocopherol in a dose of 100 mg/kg exerted a pronounced antiepileptic effect under the conditions of over kindling. On combined use of nicotinamide and pyridoxal-5-phosphate, nicotinamide, pyridoxal-5-phosphate and alpha-tocopherol the antiepileptic action was more demonstrable. Daily administration of a complex of the drugs (nicotinamide, pyridoxal-5-phosphate, alpha-tocopherol) produced a substantial reduction in epileptic activity under the conditions of overt kindling. The possibility has been demonstrated of preventing the development of epileptic activity with nicotinamide under kindling.

Animals↗
PubMed1984

[Cytophotometric study of changes in glutamate dehydrogenase and GABA transaminase in the cerebral cortex during corazole kindling].

It has been demonstrated in (CBA X C57BL/6) F1 mice that daily corazole injections (30 mg/kg) lead to the development of pharmacological kindling that manifests in a progressive increase of seizure susceptibility, seizure occurrence in response to the subthreshold convulsant dose and in demonstrable seizures. Cytophotometric study of the histological specimens of the sensorimotor cortex discovered the reduced enzymatic activity of glutamate dehydrogenase and GABA transaminase in the neurons. In the neuroglial cells, the activity of glutamate dehydrogenase also declined, whereas that of GABA transaminase tended on the contrary, towards increase.

4-Aminobutyrate Transaminase↗
PubMed1983

[Effect of electric stimulation of the dentate nucleus on focal complexes of epileptic activity in the cerebral cortex].

Acute experiments on cats were made with the use of an experimental multifocal epileptic complex (MEC) which was created by local application of different concentrations of penicillin to different zones of the neocortex. At the early stages of the MEC the epileptic activity in the seizure foci increased during electrical stimulation (ES, 100-300 Hz) of the contralateral dentate nucleus. As the epileptic activity of the MEC descended up to the disappearance of some of the dependent foci, ES elicited the suppression of the epileptic discharges in the remaining foci. ES of the dentate nucleus did not affect the overall duration of MEC existence. It is inferred that the dentate nucleus belongs to the antiepileptic system of the brain.

Animals↗
PubMed1983

[Effect of electric stimulation of the dentate nucleus of the cerebellum on epileptogenic foci in the cerebral cortex].

It has been shown in acute experiments on cats that electrical stimulation (ES, 100-300 Hz) of the dentate nucleus leads to suppression of interictal discharges elicited by application of low concentrated penicillin solution to the neocortex. ES of the nucleus causes activation of discharges in a more powerful focus of seizures. As its activity gradually attenuates the seizure discharges are suppressed during ES. The period of focus existence is shortened by ES of the nucleus. ES of the ipsilateral nucleus produces no marked effect, leading only to the decreased frequency of seizure discharges. It is concluded that the dentate nucleus plays a significant role as part of the brain antiepileptic system.

Animals↗
PubMed1982

[Effect of pantogam, nicotinamide, and phenazepam on seizure activity].

Effects of different doses of nicotinamide, pantogam, pnenazepam, and their combined actions on generalized seizures induced by pentylenetetrazole (60-100 mg/kg) were studied in acute experiments on mice. It was shown that pantogam (500 mg/kg) doubled the latent period of seizures, considerably attenuated the intensity of attacks and lethality, whereas given in a dose of 1000 mg/kg it completely prevented the animals' death. Nicotinamide (250-500 mg/kg) increased the latent period of seizures without affecting the intensity of seizures or lethality. Nicotinamide (1000 mg/kg) prevented the development of clonico-tonic attacks and lethality. The antiseizure effects of nicotinamide depended on the time of its injection. Phenazepam (1.4 mg/kg) abolished seizures and in a dose of 0.1-0.7 mg/kg protected the animals from death and considerably relieved seizure manifestations. During combined injections of these compounds, the antiseizure effect was more pronounced and could be attained by decreasing the drug doses.

Animals↗
PubMed1981

[Further study of the antiepileptic properties of nicotinamide].

Acute experiments on cats have shown that nicotinamide (100-500 mg/kg) injected intravenously suppresses the epileptic activity in solitary foci produced in the cortex by application for several seconds of a 0.5% solution of penicillin as well as in the complex of foci produced by application of a 0.1--3% solution of strychnine to various cortical zones. Nicotinamide (500-100 mg/kg) does not affect the character of the epileptic activity of foci created by application of 1% penicillin to the cerebral cortex or on the generalized epileptic activity produced by application of concentrated solutions of strychnine or penicillin. In an epileptic focus produced by application of 5-10% acetylcholine and 0.5% proserine, injection of nicotinamide leads at first to the disappearance of after-effect discharge and then of spike potential. It is concluded that nicotinamide has an antiepileptic activity.

3-Mercaptopropionic Acid↗