[Transcortin in rat kidney tissue: distribution in microsomal fractions]. / Transkortin v tkaniakh pochek krys: raspredelenie v mikrosomal'noi fraktsii.

During chromatography of renal tissue cytosolic proteins on DEAE-cellulose the protein specifically binding [3H]corticosterone is eluted within the potassium phosphate concentration range of 0.08-0.10 M. Analysis of kidney slices revealed the synthesis of [3H]transcortin whose electrophoretic mobility was close to that of the blood plasma protein. Using radioimmunochemical methods, it has been found that transcortin-specific [125I]IgG antibodies interact with growing polypeptide chains of membrane-bound polyribosomes. Free polyribosomes do not bind antibodies against transcortin.

[Activity of 5-alpha- and 5-beta-steroid reductases in subcellular liver structures from rats bearing Walker carcinosarcoma]. / Aktivnost' 5-alpha- i 5-beta-steroidreduktazy v subkletochnykh strukturakh pecheni krys pri roste kartsinosarkomy uokera.

Change in the activity of cytoplasmic 5 beta- and microsomal 5 alpha-steroid reductases was studied in tumor bearing rats. As shown by thin-layer chromatography conversion of 3H-corticosterone into 5-alpha and 5 beta-dihydro-compounds was decreased 3-fold in rats bearing Walker tumor. Activity of both these enzymes exceeded the initial level 2-3-fold in presence of exogenous NADPH. At the same time, activation of glucose 6-phosphate dehydrogenase was accompanied by simultaneous alteration in content of transcortin-bound corticosterone in rat blood plasma. 5 alpha-reductase was detected in membranes of liver tissue endoplasmic reticulum and in the fraction of free polyribosomes.

[Effect of transcortin on the corticosterone-transforming activity of cytosol from the rat liver]. / Vliianie transkortina na kortikosterontransformiruiushchuiu aktivnost' tsitozolia pecheni krys.

The study of transcortin role in 3H-corticosterone metabolism has shown that transcortin of blood plasma from rats bearing Walker carcinosarcoma preserves the hormone conversion to dihydrocompounds 4 time less intensively than transcortin taken from healthy rats. Inactivated transcortin exerts no effect on the rate of formation of 5 beta-metabolites. Under the influence of homogeneous transcortin samples, a decrease in the content of 5 beta-reduced corticosterone metabolites is revealed to occur depending on transcortin concentration in the system. It is shown that in incubation systems where hormone is in the bound state the metabolism preserving capacity of transcortin depends on the temperature degree. The transcortin activity on corticosterone metabolism is supposed to be closely related to the intensity of its complexing with transcortin.

[Interaction of glucocorticoids with receptors of rat liver cells during the growth of Walker carcinosarcoma]. / Analiz vzaimodeistviia gliukokortikoidov s retseptorami kletok pecheni krys pri roste kartsinosarkomy Uokera.

Specific glucocorticoid hormone receptors with Kass = 1.23 X 10(8) M-1 and the content of binding sites 5.59 X 10(-13) moles per mg of protein were found in liver cytosol of intact rats. During growth of Walker carcinosarcoma concentration of binding sites decreased approximately by 40%, whereas the affinity of receptors to the hormone did not mainly altered. At the same time, a considerable decrease was noticed in the content of free binding sites not bound with endogenous corticosteroids. After thermoactivation about 50% of 3H-dexamethasone receptor complexes acquired the ability to bind DNA, while in the same experimental conditions only about 20% of the complexes were activated in cytosol of tumor-bearing rats. With growing of the tumor thermal inactivation of the hormone-receptor complexes was not practically altered both in presence and in absence of molybdate ions. In a solution with low ion strength at 25 degrees a half-life dissociation of 3H-dexamethasone-receptor complexes was equal to 0.042 and 0.084 min-1, respectively, in cytosols of healthy and tumor-bearing rats.

[Characterization of cytosol and nuclear glucocorticoid receptors from rat liver tissue in hepatocarcinogenesis]. / K kharakteristike tsitozol'nykh i iadernykh retseptorov gliukokortikoidov v pecheni krys pri gepatokantserogeneze.

Specific receptors with high affinity for dexamethasone (Kass = 2.03 = 4.04 . 10(8) M-1) were found in liver cytosole of control rats as well as in animals with hepatocarcinogenesis caused by diethylnitrosamine and in cytosole of primary hepatomas. Amount of the binding sites for dexamethasone varied depending on severity of the blastomatous process (3.4 = 0.17 X X 10(-13) M/mg protein). The receptors from liver tissue of control rats, malignant liver and hepatomas were similar in their binding patterns and in chromatigraphic properties. Content of dexamethasone-receptor complexes accepted by chromatin was decreased by 50% in cytosole of malignant liver cells as compared with controls. The same alteration in binding of cytosole-receptor complexes of DNA from malignant liver tissue was found by means of affinity chromatography.

[Chromatographic transcortin analysis of the blood plasma in tumor-bearing rats]. / Khromatograficheskii analiz transkortina plazymy krovi krys-opukholenositelei.

The binding of 3H corticosterone was studied comparatively in partly purified preparations of blood plasma transcortin in intact and tumor-bearing rats at the 12th day after transplantation. By means of chromatography on DEAE-cellulose and hydroxylapatite transcortin was purified about 200 times. It was demonstrated that the content of bound 3H corticosterone in 1 mg of protein in blood plasma preparations from tumor-bearing animals is 3.5 times less than in the plasma of intact rats. The observed reduction of the transcortin binding capacity in the blood plasma of rats with Walker carcinosarcoma is retained also in purified preparations of the blood plasma tanscortin of tumor-bearing rats.