Expression of genes for thioredoxin 1 and thioredoxin 2 in multidrug resistance ovarian carcinoma cells SKVLB.

The expression of genes for thioredoxin isoforms Trx1 and Trx2 was studied in sensitive SKOV-3 and resistant SKVLB human ovarian carcinoma cells. The development of doxorubicin resistance was accompanied by a significant increase in the expression of TRX1 gene and less pronounced increase in TRX2 gene expression.

[Role of the antioxidant system and redox-dependent regulation of transcription factors bcl-2 and p53 in forming resistance of human K562 erythroleukemia cells to doxorubicin]. / Rol' antioksidantnoi sistemy i redoks-zavisimoi reguliatsii transkriptsionnykh faktorov bcl-2 i p53 formirovanii rezistentnosti kletok K562 éritroleikemii cheloveka k doksorubitsinu.

Prooxidant effect of chemotherapeutic agents is of significant interest in connection with activation of oxidative stress in cancer cells. Role of development of adaptive antioxidant response to the rise of resistance to cytotoxical effect of doxorubicin (DOX) has been studied in human erythroleukemia K562 cells. Growth of resistance to DOX caused enhancement of antioxidant enzymes (Cu, Zn-SOD, Mn-SOD, catalase) elevation of Mn-SOD activity being predominant. Additional increasing of antioxidant level was elevation of GSH maintenance and level of GST-related enzymes (glutathione peroxidase, glutathione S-transferase, glutathione reductase) in resistance K562/DOX cells. The enhancement of antioxidant system prevented activation of lipid peroxidation. Furthermore, the antioxidant growth caused decrease of level of proteintyrosine kinases, thioredoxin, thioredoxin reductase in contrary to elevation of glutaredoxin activity. Increasing of Bcl-2 and suppression of p53 levels was found to be caused by the change of redox state of K562DOX cells. The data support the suggestion that adaptive antioxidant response to prooxidant effect of DOX promotes the development of cellular drug resistance.

[Changes in the endogenous hormonal background due to anabolic steroids]. / Izmenenie éndogennogo gormonal'nogo fona anabolicheskimi steroidami.

Studies into the effects of metandrostenolone and ecdisterone, anabolic steroids of different classes, on the content of hormones in blood plasma made it possible to establish that metandrostenolone produces appreciable changes in the hormonal background: a short-term increase in the content of corticosterone but a decline in the concentration of somatotropic hormone (STH). The long-term administration of metandrostenolone brings about a reduction of the content of testosterone. Unlike metandrostenolone, ecidsterone provoked but an increase in the content of corticosterone both on single and long-term administration. It is concluded that the rise of the content of corticosteroids in blood plasma under the influence of the tested drugs may be a factor favoring mobilization of biochemical processes in skeletal muscles in response to physical exercise. Meanwhile the change in the corticosterone:testosterone:STH ratio in blood may cause side effects due to the long-term use of metandrostenolone and other anabolic derivatives of androgens.

[The mechanism of the thymolytic action of anabolic steroids]. / Mekhanizm timoliticheskogo deistviia anabolicheskikh steroidov.

The administration of testosterone and metandrostenolone to male rats in doses of 10 and 20 mg/kg for 10 days produced a decrease of the thymus mass and a reduction of the thymic serum factor content. A phytoecdisteroid ecdisterone not possessing the androgenic activity fails to influence the thymus mass and the content of the thymic serum factor.

[Thymolytic effects of methandrostenolone]. / Izuchenie mekhanizmov timoliticheskogo éffekta metandrostenolona.

It was shown, that in castrated rats dianabol (10 mg/kg of body mass daily for 7 days) inhibits the protein synthesis in thymus. The binding analysis of 3H-dianabol showed the specific binding sites in thymic cytosol, which are identical to those for androgens. Isolated thymocytes didn't bind dianabol.

[The action of methandrostenolone and ecdysterone on the physical endurance of animals and on protein metabolism in the skeletal muscles]. / Deistvie metandrostenolona i ékdisterona na fizicheskuiu vynoslivost' zhivotnykh i obmen belkov v skeletnykh myshtsakh.

The results of the comparative study on the myotropic activity of methandrostenolone and ecdysterone and their effects on physical endurance of animals suggested that ecdysterone possessing a wider spectrum of the anabolic action on the contractile proteins of the skeletal muscles exerts a more pronounced influence on physical endurance of animals without their preliminary training.

[Evaluation of the capacity of the thymus to accumulate testosterone and of the nature of its interaction with the thymocytes]. / Otsenka sposobnosti timusa akkumulirovat' testosteron i kharaktera vzaimodeistviia ego s timotsitami.

It was found out that thymus accumulated 3H-testosterone from blood at the same degree as liver, prostate and skeletal muscle. However, hormone was quickly eliminated from the thymus and prostate accumulated it. Thymocytes bound about 5% of testosterone accumulated by the organ. The dependence of binding of 3H-testosterone by thymocytes in vitro and the absence of competition between labelled and unlabelled forms of hormone were revealed. The results obtained make it possible to conclude that thymocytes lack the systems of specific binding of androgen.

[Steroid hormones and lysosomes]. / Steroidnye gormony i lizosomy.

The data on lysosomotropic effect of steroid hormones are reviewed. The effect of steroid hormones correlated with the type of tissues and dose of hormones. A possible role of lysosomes in realization of hormonal signal in the cell biological response is discussed.

[Effect of 7 days of administration of prednisolone and methandrostenolone on the incorporation of glycine-1-c14 into liver, thymus and splenic proteins]. / Vliianie 7-dnevnogo vvedeniia prednizolona i metandrostenolona na vkliuchenie glitsina-1-C14 v belki pecheni, timusa i selezenki

Daily injections of prednisolone (10 mg/kg) for a space of 7 days to albino male-rats cause an increased synthesis of nuclear and mitochondrial proteins without changing the protein synthesis of other liver fractions. Following injection of prednisolone the protein synthesis in the spleen went up and in the thymus remained unchanged. This was paralleled by stronger decay processes of the lymphoid organs. Under identical conditions methandrostenon intensified the proteins synthesis in the nuclear fraction of the liver alone. It made run low the processes of the thymus and spleen proteins biosynthesis without affecting materially the weight of the lymphoid organs.