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Biomedical subjects

R Ovcharov

Publications and source records attributed to R Ovcharov.

At least 37 records · Page 2Linked to original sources
PubMed1981

[Interrelationship of the tranquilizers diazepam and lonetil with dopamine mediation in the central nervous system].

The tranquilizers Diazepam and Lonetyl were examined on rats for their influence on the higher nervous system, using the method of "double escape". Pharmacologic analysis of their action on dopaminergic structures in the central nervous system was performed as well. In this analysis they used dopamine agonist Apomorphine and dopamine antagonist Haloperidol. The authors established that diazepam is small doses did not inhibit dopaminergic system and its activation affected favourably its action, improving conditioned reflex activity. Inhibition of dopaminergic activity by Haloperidol reduced the effect of Diazepam. Lonetil, in contrast to diazepam, inhibited dopaminergic mediation and its sedative effect was increased considerably by Haloperidol.

Animals↗
PubMed1979

[Effect of beta-adrenergic drugs on humoral immune response factors].

The authors examined the influence of beta-adrenergic stimulators Isoprenaline and Salbutamol as well as beta-adrenergic blockers Propranolol, Practolol and Pindolol on the proliferation of cells, forming plaques, 7S-immunoglobulins, hemagglutination titres and hemolytic activity of the complement. Primary stimulation with subsequent inhibition was induced by beta-adrenergic agonists and inhibition--by beta blocker Propronanol in a base of 10 mg/kg on the proliferation of cells, forming antibodies. The results were in correlation with hemagglutination titres. Salbutamol and beta-blockers inhibited immune hemolysis. The mechanisms of the observed effect are discussed in respect to the specific and nonspecific effect of the drugs used.

Adrenergic beta-Agonists↗
PubMed1979

[Effect of halothane (narcothane) on intrauterine fetal development].

The authors examined the effect of chalotane (narcotann ne-Spofa) on the development of a rat fetus. The rats were divided into groups and were narcotised for a period of 4 hours as well as 4.5 days. One of the group was narcotised from the 8 to the 13 day of gestation. Narcosis was made in chambers with dynamic inhalatory regimen at concentration of narcotane of 10 mg/m3 and 250 mg/m3. There was blastopathogenic effect of narcotane, manifested by an early resorption of nidaded ova, by nonspecific action on the fetus, which inhibited growth and development of the fetus and raised the mortality of the fetuses. The amount of estriol was diminished in mothers, treated with 250 mg/m3 of the drug.

Alkaline Phosphatase↗
PubMed1979

[Appropriate and inappropriate use of foreign words in the language of Bulgarian experimental medical disciplines].

The authors make an attempt to indicate inappropriate usage of some frequently used words and expressions in the medical literature, adopted in the Bulgarian language most frequently from the English language. They stress to keep close to the classical languages-Greek and Latin, which are at the base of the medical terminology. The authors present examples of words from contemporary languages, which are universally accepted and in which the semantic purity of the native language could lead to pedantry and vagueness. They point out that the concepts with smaller volume could be expressed by the most suitable words from the Bulgarian language, for example the names of methods or concepts, describing private regularities.

Bulgaria↗
PubMed1978

Changes in the convulsion threshold and in the level of brain biogenic amines in rats chronically treated with phenobarbital or diazepam.

In experiments on 72 male Wistar rats, chronically treated with phenobarbital and diazepam, studies are made of the change in the convulsion threshold after sound stimulation during treatment and after withdrawal of the drugs. The level of biogenic amines in the brain at the end of the treatment (60th day) and after withdrawal of the drugs (3rd day) was also determined. The convulsion threshold was found to be considerably lower on the 3rd day after drug withdrawal in rats treated with phenobarbital and to a lesser extent (also on the 3rd day) in rats treated with diazepam. Serotonin level is considerably lower in both groups of animals. The significance of the disturbed correlation between serotonin and noradrenaline and particularly the sharp decrease of the serotonin level for the appearance of intensified convulsion activity is discussed.

Animals↗
PubMed1977

[Effect of beta-adrenergic blockaders on the uterine musculature of rats].

The authors carried out a study on beta-adrenergic blockers Proprafnolol, Pindolol and Practolol, on an isolated uterus of a rat, obtained at various phases oestrus. The Beta-adrenergic blocker Pindolol manifested inhibiting effect on the spontaneous contractility of the uterus more marked after elevated level of gestagens. The pharmacological analysis gave foundation to the authors to assume that the relaxation of Pindolol was due to direct myotropic action. Propranolol in large doses and at high gestagenic level manifested antioxytocic activity. Practolol did not affect both spontaneous uterine activity as oxytoxin contraction.

Adrenergic beta-Antagonists↗
PubMed1977

Quantitative determination of drugs by means of densitometry of thin-layer chromatograms. Part 6 Determination of 1-benzhydril-4-allypiperazine dihydrochloride in biological media.

A quantitative method for determination of 1-benzhydril-4-allypiperazine dihydrochloride (As-2) in blood is proposed, based on direct densitometry of t.l.c. plates. The main advantage of the method consists in the fact that it can be applied for determination of As-2 in biological samples in the presence of its metabolites and other components of the investigated samples. The statistical treatment of results obtained from ten analyses shows that the method has no systematic error and the relative percentage error is +/- 8.5%. The lowest concentration which can be determined is 5 microng/1 ml plasma. It has been established that As-2 administered intravenously in the maximally tolerable dose of 22 mg/kg can be detected in the blood after the first min (RF = 0.45). Ten min after application one major metabolite (RF = 0.35) is observed under UV-light. When administered per os in the maximally tolerable dose of 100 mg/kg, As-2 is established in the blood after 15 min while the metabolite mentioned above is detected by the thirtieth min.

Animals↗
PubMed1976

Pharmacological analysis of certain mechanisms of morphine addiction.

The effects of L-Dopa, Methysergid, Diphenhydramine hydrochloride and LSD on the development of morphine dependence and the abstience syndrome after its withdrawal, were tested in experiments on 200 male Wistar albino rats. L-Dopa had no efect on the development of physical morphine dependence, while Methysergid prevented its development. Applied in rats during the abstinence syndrome, LSD intensified their aggressivity with no influence on the analgesic effect of morphine. Diphenhydramine reduced the aggressiveness of the rats during the abstinence syndrome. Biochemical tests show that in morphine-tolerant rats there was an increase in the content of brain serotonin, less of dopamine and no changes in noradrenaline. The significance of the brain levels of serotonin, dopamine and noradrenaline for the development of physical morphine-dependence is discussed. It is pointed out that serotonin and dopamine play an important role both for the origin of the physical morphine dependence, and in the abstinence syndrome after its withdrawal.

Animals↗
PubMed1976

[Effect of beta-adrenergic blockers on complement].

The authors, examined the effect of beta-adrenergic blockers Propranolol, Pindolol, Practonol and P11 on complement in the serum of guinea pigs after continuous administration. The follow-up was made dynamicaly: on the 10th, 20th and 30th day. There was a considerable lowering of the complement level on the 20th and 30th day in all animals treated with beta-adrenergic blockers. The experiments in vitro showed that the effect of Propranolol and and P11 on the serum of persons, guinea pigs and rabbits presented data on the complement inhibition, having the direct effect on the first component of the complementary systems.

Adrenergic beta-Antagonists↗
PubMed1975

[The effect of apamine on the inflammatory process].

The authors examined the effect of apamine on rats, rabbits and guinea pigs with experimental inflammation. Apamine inhibited serotonine and dextrane oedema on the hind paw of a rat as well as the excudative reaction in inflammation, induced by Croton oil. Apamine manifested antiserotomine effect on an isolated ileum of a guinea pig. It inhibited the increase of haptoglobulin and mucoprotein in serum of animals with experimental inflammation.

Animals↗
PubMed1975

[Morphine interaction with reserpine and amphetamine on prolonged administration to rats].

The authors carried out studies on 300 white rats of the Wistar strain and examined the influence of reserpien and amphetamine on creating physical dependence to morphine in rats after sixty days of combined application. Resepine, used continuosty with morphine, hindered the development of tolerance to the analgetic and toxic effect of morphine. However on the background of a three-day administration in rats with reserpine the morphine revealed considerably less toxicity. The amphetamine did not stop the development of the morphine dependence. The amphetamine, administered tere singly for a period of sixty days, created dependence in the rats. The results are discussed in view of the participation of cerebral catecholamines and serotonine in the creotion of morphine dependence.

Amphetamine↗
PubMed1975

[Effect of beta-adrenergic blockaders on the bioelectrical activity of the mesenchephalic reticular formation].

The authors examined the beta-adrenergic structures in the mesencephalic formation (MSF) in view of establishing their role on the activity of MSF in view of establishing the in rols on the activity of MSF itself and the relationship of the same formation with the cerebral cortex and the lymbic system. It was established that beta-adrenergic blockers after their local application in MSF could inhibit its function. The data from the effect on the induced bioelectrical activity indicated also diminution in the functional activity of MSF. The authors found that the inhibiting influences of beta-blockers were abolished by their antagonist isoprenalite. An inference is made that there are beta-adrenergic structures, which act excitatory.

Adrenergic beta-Antagonists↗