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Biomedical subjects

G I Samokhvalov

Publications and source records attributed to G I Samokhvalov.

At least 19 recordsLinked to original sources
PubMed1992

[Effects of ubiquinone-9 on lipids of nuclei and chromatin of the rat liver under continuous irradiation].

The influence of continuous gamma irradiation on the lipids of nuclei and chromatin of rat liver at a dose-rate of 0,129 Gy/day for 155 days (a total dose of 20 Gy) and by feeding of ubiquinone-9 has been studied. The amount of phosphatidylcholine with phosphatidylserine and phosphatidyl-ethanolamine in liver nuclei of irradiated rats was found to increase. Ubiquinone-9 had a normalizing effect. A decrease of cardiolipin was observed in the liver chromatin of irradiated rats. The amount of free fatty acids had a tendency to decrease in homogenate, nuclei and liver chromatin of irradiated rats. Ubiquinone was found to increase the amount of free fatty acids up to the control level. The amount of cholesterol in nuclei was increased after irradiation and that in chromatin tended to rise. Ubiquinone-9 significantly decreased the amount of cholesterol in nuclei and chromatin of irradiated rats.

Animals↗
PubMed1991

[Cardioprotective effect of combined use of coenzyme Q9 and cyclohexyladenosine in ischemia, reperfusion and acute myocardial infarction].

Effects of coenzyme Q9 (25 mg/kg), N6-cyclohexyl adenosine (CHA, 100 micrograms/kg) and their combination were compared in rats with short-term or permanent ligation of the left coronary artery. The following parameters were evaluated in three series of experiments: 1) incidence and duration of ventricular fibrillation and tachycardia during coronary occlusion (10 min) and consecutive reperfusion (5 min); 2) contractility and electrical stability of the heart (ventricular fibrillation threshold) in animals with 2-day myocardial infarction; 3) ischemic myocardial mass after coronary occlusion (5 min) and necrotic tissue mass in 2-day myocardial infarction. The rats were given oral drugs 5 days and 2 hours before the study. All the experiments were performed in open-chest anesthetized (nembutal, 50 mg/kg) rats exposed to ventilation at room air. Both the coenzyme Q9 and CHA significantly reduced the incidence and duration of coronary occlusion and reperfusion arrhythmias, prevented cardiac contractile depression (heart rate.developed pressure) and increased ventricular fibrillation threshold). The effect of coenzyme Q9 was more marked than that of CHA. Coenzyme Q9 substantially reduced necrotic tissue mass while CHA diminished ischemic tissue mass. At the same time the total cardioprotective action of the Q9 + CHA combination was more pronounced than that of them used alone.

Adenosine↗
PubMed1985

[Effect of ubiquinone on phospholipid metabolism in radiation injury].

The synthesis and phospholipid content in the liver, intestine and spleen in normal and irradiated rats administered ubiquinone-9 were studied with the use of 3H-serine. Ubiquinone markedly activated decarboxylation of phosphatidylserine and suppressed transformation of phosphatidylethanolamine to phosphatidylcholine in rat liver and spleen. The effect was also observed in the organs of irradiated animals. In rat intestine, administration of ubiquinone normalized a sharp gamma-irradiation-induced inhibition of transformation of phosphatidylcholine from phosphatidylethanolamine. The catabolism of phospholipids under the action of ubiquinone and radiation was inhibited in the liver and, on the contrary, was activated in radiosensitive organs.

Animals↗
PubMed1984

[Effect of synthetic beta-carotene on the formation of cytolytic T-lymphocytes].

The effect of intraperitoneal injection of beta-carotene in different doses on the formation of cytolytic T lymphocytes (CTL) in a one-way mixed lymphocyte culture (MLC) of allogeneic mice was studied. The maximal cytotoxic activity of lymphocytes was attained in the MLC with splenocytes of mice which received 10 mg/kg beta-carotene 6 days before experimentation. The correlation was studied between the beta-carotene ability to stimulate CTL formation and antineoplastic activity. It was discovered that injection of beta-carotene in doses and times provoking maximal CTL induction had no effect on the animals' lifespan and the size of transplanted sarcoma 180.

Animals↗
PubMed1983

[Effect of retinoids on the development and growth of experimental tumors].

The ability of six retinoids to inhibit cancer growth was tested on mice with Lewis lung carcinoma, PRG and RSM-5 tumors. It was shown that all tumors possess individual sensitivities to retinoids. The most effective substances were: methyl retinoate (all-trans and 13-cis isomers) and a retinoid with a small side chain and an oxidated beta-iononic ring (substance 3). Each of those three retinoids was tested for an ability to prevent methylcholanthrene-induced carcinogenesis in the skin. All-trans methylretinoate had the most pronounced effect; however, it was the most toxic, too.

Animals↗
PubMed1982

[Antitumor and toxic properties of retinoid C15].

A study was made of antitumor and toxic properties of retinoid C15 which has some characteristic structural features of retinoic acid natural metabolites; such as ethyl-2E, 4E-3-methyl-5-/2,6-dimethyl-6-ethoxycarbonyl-/3-oxo-1-cyclohexene-1-yl/-2,4-pentadienoate. The substance inhibited the growth of transplantable tumors of the uterine cervix. Lewis carcinoma and rumen cancer. This ability was dependent on the tumor growth rate. The substance proved less toxic then retinoic acid or methyl retionate. Injection of retinoid C15 was accompanied by the widening of the paracortical zone of the mesenterial lymph node and by the increased number of lymphoid follicles in the spleen.

Animals↗
PubMed1977

[Effect of hexahydroubiquinone-4 (KoQ4) on the bioenergetics and functional activity of the myocardium in ischemia].

The effect of KoQ4 on the energetics, contractility, and electrogram of the ischemized myocardium was studied in acute experiments on dogs with induced myocardial ischemia. Intracornoary administration of KoQ4, 1.3 mg/kg, directly into the focus of ischemia for 15 min promoted a decrease in the lactate level in blood draining from the ischemic zone as compared to the control data in the absence of a difference in the dynamics of the pyruvic acid content. In distinction to the control experimental series, there was no decrease in the concentration of glucose in samples of venous blood draining from the focus of ischemia. Under the effect of KoQ4 the amplitude of left ventricular pressure and the maximum rate of its growth (dp/dt) increased moderately and the ST segment and ST/R coefficient of the epicardial electrogram from the border zone of ischemia decreased. It was shown in the rat experiments that preliminary intravenous administration of KoQ4 (14 mg/kg) increased myocardial resistance to oxygen deficiency under conditions of diacetylcholine-induced apnoe.

Acute Disease↗
PubMedDate not supplied

[Radioprotective properties of ubiquinones during acute and chronic irradiation of rats].

Protective and therapeutic effect of ubiquinone-8 was demonstrated on rats exposed to 8 Gy radiation. There was a 16-20% increase in the survival rate of the irradiated rats as compared with the controls. The per os administration of ubiquinone-8 during a five-month period in conditions of chronic exposure arrested the radiation-induced accumulation of lipids in rat liver and somewhat improved the dynamics of the body mass growth in the exposed rats.

Acute Disease↗
PubMedDate not supplied

[Comparative study of the biological activity and toxic effect of 1alpha-hydroxycholecalciferol and ergocalciferol in rats].

Single administration of 0.25 microgram of sunthetic Ialpha-hydroxycholecalciferol (IalphaOHD3) into nephrectomized rats, maintained at D-avitaminous diet, improved the active transport of calcium ions against the concentration gradient in small intestine of these animals, whereas ergocalciferol was biologically inactive under the same conditions. Administration of IalphaOHD3 during 5 days at a dose 0.025 microgram normalized calcium content in blood serum of rats with D-avitaminosis, Increased doses of IalphaOHD3, administered into intact animals, caused transient hyperphosphatemia, hypercalcemia, calcinosis of internal tissues (kidney heart, aorta) as well as death of some animals. IalphaOHD3 exceeded 400-fold the hypercalcemic and calcinose effects of ergocalciferol. LD50 for IalphaOHD3 was equal to 100 microgram/kg, if it was administered during 5 days per os. Tissue calcinosis was developed after administration of a daily dose 10 microgram/kg, moderate hypercalcemia was caused by a daily dose 1 microgram/kg or 0.25 microgram per an animal; this amount is only 10-fold higher as compared with the physiologic requirement. Ergocalciferol caused hypercalcemia and metastatic calcification only at a dose 4000 microgram/kg. Clinical use of IalphaOHD3 at doses, exceeding the physiologic requirements, has to be prohibited due to high activity of the preparation and to toxicity of its increased doses.

Animals↗
PubMedDate not supplied

[Effect of ubiquinone-9 on the blood coagulation system].

The effect of a single and 2-week administration of ubiquinone-9 on the blood coagulation system and the functional activity of platelets was studied in the experiments in vitro and in vivo on rats. It was shown that a single dose of 150 mg/kg of ubiquinone decreased adhesion and that of 5 mg/kg decreased aggregation of platelets. Both with a single and 2-week drug administration in doses of 5, 50 and 150 mg/kg an insignificant decrease of coagulability was observed.

Animals↗
PubMedDate not supplied

[Effect of three retinoids on the growth of experimental tumors].

Influence of retinoid C17-diester retinyldimedone and L-tocopherylretinoate on the growth of transplanted tumors was investigated in F1 (C57Bl/6 X CBA) strain of mice. The retinoids studied proved to be less toxic than retinoic acid. Both retinoid C17-diester and L-tocopherylretinoate reduced growth of cervical cancer, while retinyldimedone inhibited growth of Lewis carcinoma (lung tumor) and of stomach carcinoma.

Animals↗
PubMedDate not supplied

[Ubiquinone-9 and ergosterol from Candida paralipolytica yeasts].

Ubiquinone-9 and ergosterol were extracted with hexane from the yeast Candida paralipolytica after hydrolysis with KOH in EtOH with the yield 0.026 and 0.14%, respectively. Ubiquinone-9 was purified by chromatography and recrystallization from absolute alcohol.

Candida↗