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Biomedical subjects

E E Evartau

Publications and source records attributed to E E Evartau.

15 recordsLinked to original sources
PubMedDate not supplied

[Antagonists of ionotropic glutamate receptors as the object of research in psychopharmacology].

Ionotropic glutamate receptors antagonists are now widely considered as potential medications for a variety of disorders, such as seizures, neurodegenerative diseases, stroke, and opiate tolerance and dependence. There is a growing body of evidence suggesting that the safest drugs are to be found amongst antagonists acting at glycine and polyamine sites of NMDA-receptor complex, low-affinity channel blockers, subtype-selective competitive NMDA-receptor antagonists, as well as non-NMDA glutamate receptors antagonists. These antagonists exhibit little or no abuse liability and are less likely to induce phencyclidine-like attention deficits and disruption of sensomotor gating. Meanwhile, these drugs retain most of the potentially useful properties, including anxiolytic and antidepressant effects.

Animals↗
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[The effect of N-methyl-D,L-aspartic acid on the nociceptive reaction of mice].

Intraperitoneal NMDLA was pharmacologically studied in mice for effects by using the hot-plate test. The agent given in a subconvulsive dose of 50 mg/kg showed a biphasic action: 5 minutes after administration there was hyperalgesia (Phase I) followed by hypoalgesia (Phase II) 15 minutes later. The effects of phencyclidine, ketamine, morphine, naloxone, bromocriptine and isradipine on NMDLA's analgetic action were also examined. Bearing in mind the fact that the action of NMDLA is decreased by isradipine in Phase I and by receptor-acting agents in Phase II it is suggested that there is a great difference in the patterns of the two phases of the analgetic action of NMDLA systemically used.

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PubMedDate not supplied

[The psychopharmacology of narcotics: a preclinical study].

Simple and economic tests for estimating addictive potential of drugs using conditioned place preference and intravenous self-administration paradigms have been developed. Various groups of substances were revealed among 12 opioids which differed by their potencies in analgesics and reinforcing tests. Index of "narcological safety" and "addictive index" were proposed for comparative evaluation of therapeutic and adverse (addictive) effects. Using the self-administration procedure a group of addictive psychostimulants were investigated and quantitative criteria for the reinforcing action of them were derived. The analgesic and reinforcing effects of morphine have been dissociated by administration of the calcium-channel blocker isradipine.

Animals↗
PubMedDate not supplied

[The intravenous self-administration of narcotics in mice].

Four commonly and largely abused drugs morphine, cocaine, amphetamine, cathinone and sympathomimetic ephedrine were investigated, using intravenous self-administration by naive mice, with special regard to methodological aspects of these techniques. All drugs showed a similar bell-shaped concentration response curves, which are typical of compounds with high addictive potential. A new method of analysis of the reinforcing properties allowing to disregard motor side effects of drugs nas been proposed. Procedure and analysis aspects of described techniques as well as the possibilities of its application for screening of addictive substances are discussed.

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PubMedDate not supplied

[Effect of chronic morphine administration on the "reward" system in rats].

The influence of morphine on lateral hypothalamic self-stimulation in rats was studied, The drug was injected in stepwise increasing doses from 20 to 60 and 120 mg/kg per injection. A total of 30 injections were performed in 15 days. Initial doses of every new drug injection period exerted predominantly a suppressive action upon self-stimulation, while additional injections resulted in a stable and clearcut activation of the central mechanisms mediating "rewards".

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[Rat behavior in an "open field" when chronically administered morphine].

15-day long administration of morphine in doses of 20 to 120 mg/kg, injected twice daily produced initially a depression followed by an increased locomotor activity, more pronounced grooming behavior and less so--rearing. Abnormal forms of behavior like combined arrests and rapid movements, circling, stereatyped gnawing were also observed. Abstinence provoked by withdrawal of morphine or nalophine was characterized predominantly by the stimulation of locomotion and grooming with depressed rearing.

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PubMedDate not supplied

[Influence of naloxone on the activating effect on emotionally positive brain systems of substances that induce dependence].

Influence of naloxone on emotionally positive reactions facilitation produced by drugs with a dependence potential has been studied in rats. Lateral hypothalamic self-stimulation activated by heroin dropped to the initial level or was depressed. Some of the animals showed symptoms of opiate withdrawal. The effects of cocaine and amphetamine remained unchanged after the blockade of opiate receptors. Naloxone exerted a partial antagonistic action toward the activation of reward after diazepam and pentobarbital administration.

Amphetamine↗
PubMedDate not supplied

[Self-stimulation reaction of the hypothalamus in single and repeat administrations of ethaminal sodium].

Pentobarbital facilitated hypothalamic self-stimulation in doses from 1 to 10 mg/kg intraperitoneally. Under concurrent self-stimulation and intravenous self-administration two phases of pentobarbital action were distinctly revealed--activating and inhibitory. The facilitating effect of pentobarbital was blocked by the antiadrenergic drugs, butyroxane, pyrroxane and carbidine as well as was partially antagonized by naloxone. After chronic treatment (20 mg/kg daily) initial inhibition of self-stimulation was replaced by facilitation by days 3-4 of the experiment. Injection of pentobarbital in a daily dose of 3 mg/kg resulted in gradual development of tolerance to the facilitation action of the drug on self-stimulation and in that of dependence. Two types of abstinence reactions after pentobarbital withdrawal are described. The method proposed appears to be sensitive for studying barbiturate dependence.

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PubMedDate not supplied

[Effect of psychotropic agents on the manifestation of the morphine abstinence syndrome in mice].

Abstinence syndrome pattern produced by withdrawal of morphine injections in doses of 240 mg/kg daily was studied in experiments on mice. Pirroksan, butyroxan and carbidine (10 mg/kg intraperitoneally) inhibited manifestations of morphine withdrawal in an "open field" situation and depressed jumping activity. Phenazepam (20 mg/kg) depressed emotional hyperactivity in abstinent animals.

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PubMedDate not supplied

[The effect of the NMDA-receptor antagonist (+/-)-CPP on the conditioned-reflex activation of an operant reaction in the brain electrical self-stimulation test in rats].

Self-stimulation behaviour was studied in rats with implanted bipolar electrodes in ventral tegmental area (VTA) and guide cannulae in nuclei accumbens septi (NAC). Conditioned activation of the operant response was induced by the stimuli associated with rewarding electrical stimulation of VTA, i.e., light or subthreshold stimulation. Bilateral administration of NMDA receptor antagonist ( +/- )-CPP (2.5 mcg in each cannula) significantly attenuated the facilitating effect of the conditioned stimuli. These data provide evidence for the role of glutamatergic transmission in NAC in realization of responses with conditioned reinforcement.

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