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O V Smirnova

Publications and source records attributed to O V Smirnova.

At least 73 records · Page 4Linked to original sources
PubMed1981

[Production of antibodies to a specific estrogen-binding protein of rat liver and study of the reaction between isolated immunoprecipitates and estradiol].

High-selective antiserum (AS) against unusual estrogen-binding protein (UEBP) from male rat liver was obtained according to the following technique: 1) immunization of the rabbits by partially purified UEBP and isolation of polyspecific AS; 2) depletion of the latter AS by the UEBP-free fraction of female rat liver proteins prepared under the conditions similar to those employed in the procedure for isolation of the UEBP preparation. High specificity of depleted AS for UEBP was demonstrated by immunodiffusion, immunoelectrophoresis and agar-gel electrophoresis of UEBP and by the detected specific estradiol (E2)-binding capacity of immunoprecipitates obtained after the reaction of depleted AS with partially purified UEBP. Analysis of E2-binding activity of immunoprecipitates may be used for the discovery of UEBP antibodies in the polyspecific AS.

Animals↗
PubMed1980

[Multicomponent system of estrogen-binding proteins of the liver. Isolation and comparative properties of 4-5S and other rat liver high molecular weight proteins, which specifically bind estradiol].

Forms I and II of the estrogen receptors of female rat liver were isolated by desalting of the cytosol fraction desalting with 40% saturated (NH4)2SO4 with a subsequent gel-filtration through Ultragel AcA 44. In the absence of 0,3 M NaCl form I produces heavy aggregates and is eluted from Sepharose 6B in excluse volume. The molecular weight of from II under the same conditions as measured during gel-filtration and gradient centrifugation is 80 000. In the presence of 0,3 M NaCl the molecular weights of forms I and II are 63 000 and 77 000, respectively. The pH optima for the estradiol-binding activity of forms I and II are 6,8--8,5 and 7,4--9,1, respectively. Form II is more stable to heating and storage at 4 degrees. The binding activity of both forms of the receptors is eliminated by p-chloromercurybenzoate. The equilibrium constant for form II association with estradiol exceeds that of form I 2,5-fold and is equal to 2,4 x 10(10) M-1. The presence of 0,3 M NaCl does not affect this parameter in both cases. The association of forms I and II with estradiol and dissociation of the complexes are of a two-step type. The k+1 values for forms I and II are identical, whereas the k-1 value for form I is about two times that for form II. In terms of their competitive activity the hormone compounds tested can be arranged in the following order: estradiol less than or greater than hexestrol much greater than estrone congruent to estriol congruent to 17-deoxyestradiol much greater than 5 alpha-dihydroxytestosterone congruent to testosterone. Progesterone and corticosterone do not reveal competitive properties. The functional similarity of forms I and II of estrogen receptors from rat liver suggests that these proteins are isoreceptors.

Animals↗
PubMed1980

[Effect of several endocrine factors on the concentration of specific estrogen-binding protein in rat liver].

Differential determination of specific estrogen-binding protein (SEBP) content in the rat liver was made by ion-exchange sorption on DEAE-cellulose. The concentration of estradiol-binding sites of SEBP in liver cytosol of normal males was 11.1 +/- 1.1 pmole/1 mg protein. SEBP was not detected in the liver of immature males, of mature, mature ovariectomized and mature neonatal androgenized females. Testosterone propionate (TP) could induce SEBP in the liver of ovariectomized females. Maximal induction of SEBP was produced following daily injection of 0.3 mg of TP for 3 days. Single injection of TP had no effect. The induction of SEBP was more sensitive to TP than uterine response but required a more prolonged exposure to the androgen. SEBP was detectable in the liver for at least 43 days after discontinuance of TP injections into ovariectomized females and 56 days after castration of the males.

Animals↗
PubMed1978

[Properties of sex steroid-binding protein from Xenopus laevis blood serum and detection of an estradiol-binding component in frog liver cytosol which differs from sex steroid-binding protein].

Binding and physico-chemical properties of sex steroid-binding protein (SBP) from blood serum and those of estrogen-binding components from liver cytosol of pubertal male and female species of clawed frog Xenopus laevis were studied. It was shown that SBP from both sex species of X. laevis specifically binds estradiol (E2) (Ka=5 . 10(6) M-1). Concentration of SBP binding sites for E2 is 7 . 10(-12) mole per mg of protein. Testosterone 5alpha-dihydrotestosterone and E2 effectively compete with [3H]-E2 for SBP binding sites. Hexestrol, progesterone and corticosterone are weak competitors; estrone and E2-17-hemisuccinate do not compete at all. The Strokes radius of SBP is 4.4 nm; sedimentation coefficient is 4.6S. Molecular weight of SBP is 88000; f/f0 is 1.5 SBP from male frog sera has been purified 8.6-fold with 13% yield. Gel-filtration of [3H]-E2 complexes with liver cytosol proteins shows that the livers of male and female frog X. laevis consol proteins shows that the livers of male and female frog X. laevis contain very low amounts of macromolecular component, which specifically binds E2; this component differs from serum SBP in size and in hormonal specificity. It is assumed that this component is a receptor for estrogens.

Animals↗
PubMed1978

[Multicomponent system of estrogen-binding proteins of liver cytosol: species differences in rats, mice and guinea pigs].

Estradiol (E2) binding proteins from the liver cytoso-of mature male and female rats, mice, guinea pigs, and rabbits were investigated by gel filtration on Sepharose 6B columns. Components with Stokes radii (a) 6--7 and 2.5 nm which form specific stable complexes with E2 were found in female rats and female and male mice. The liver of male rats and male and female guinea pigs contain specific E2-binding proteins with a-about 6--7, 2.5 and less than 2.0 nm. E2 complexes with components having a values 6--7 and less than 2.0 nm relatively stable, whereas E2 complex with a component possessing a value about 2.5 nm is capable of dissociating completely within 45 minutes. It is suggested that at least some of the components of the discovered heterogenic populations of E2-binding proteins could participate in the estrogen signal reception by the liver.

Animals↗
PubMed1977

[Detection and preliminary characterization of a particular estrogen-binding protein in the liver of male rats].

Properties and isolation possibilities of an estradiol (E2) binding protein from male rat liver cytosol as possible estrogen receptor are studied. The protein is found to differ considerably in a number of characteristics from well-known receptor and non-receptor rat proteins, specifically binding estrogen. Equilibrium constant of E2-protein interaction is 1-10(8) M-1, the concentration of protein binding sites is 1.3 million per cell. Processes of E2 association with protein and the complex dissociation proceed with a very high rate. E2 and, at lesser degree, estrone, testosterone and 5-alpha-dihydrotestosterone compete for binding sites of protein with 3H-E2. Progesterone, corticosterone and a synthetic estrogen, hexestrol, denot compete. The protein studied is thermolabile and sensitive to the effect of pronase and sulfhydryl reagents. Characteristics of the protein are as follows: sedimentation coefficient--3.6S; Stockes' radius--23--25 A; friction coefficients ratio--1.05--1.12; molecular weight--36000--39000. The protein is not revealed in the liver of female rats. Ammonium sulphate precipitation, gel filtration and ionic exchange chromatography made possible to obtain 50-fold purified protein preparation.

Animals↗
PubMed1977

[Multi-component system of proteins binding estradiol in rat liver cytosol. Relationship to sex steroids].

Marked sex differences in estradiol-binding capacity ratio of components with Stokes radii (a) 7.0 and 2.5 nm in the liver cytosol of mature intact rats were found to be diminished, but not fully eliminated by gonadectomy. Prolonged administration of estradiol (50 microgram/animal for 8 days) to gonadectomized rats led to inhibition of the estradiol-binding activity of all the components in the liver cytosol of male and female animals. Administration of testosterone-propionate (2 mg/animal for 8 days) to gonadectomized animals stimulated selectivity the peculair estrogen-binding protein with a 2.5 nm not only in male, in which this protein was normally found, but also in female rats. It is supposed that sex differences in the system of estradiol-binding proteins in rat liver cytosol are determined by sex differentiation of the system at the early stages of ontogenesis, on the one hand, and by the active regulating influence of estrogens and androgens at the late stages of ontogenesis, on the other hand.

Animals↗
PubMed1976

[Nuclear estradiol receptors in several "non-target" organs of rats].

Some properties of the macromolecules of the KCl-extracts of the nuclei of the uterus, kidney, liver, testis and prostate, specifically binding estradiol (E2), were studied. These macromolecules of the uterus and the liver were found to be maximally extracted from chromatin by the 0.6 M KCl concentration. The capacity of the macromolecules of the uterine, kidney and liver nuclear extracts to bind E2 specifically is destroyed completely by pronase, but not by RNA-ASe and DNA-ase, pointing to the protein nature of these macromolecules. Only estrogenic compounds, but not testosterone, 5alpha-dihydrotestosterone, progesterone or corticosterone were capable to compete with H3--E2 for the E2--binding sites of the macromolecules of the nuclear extracts of all the organs investigaeted. It is assumed that macromolecules of the nuclei of the investigated nontarget organs specifically binding E2 are estrogen receptors.

Animals↗
PubMedDate not supplied

[Determination of Stokes' radii of the cytoplasmic receptor molecules for estradiol in various organs of rats].

A method of gel-filtration of Sepharose 6B was used; Stoke's radii (a) of some forms of cytoplasmic receptors of estrogens of the uterus, kidneys, and the liver of male and female rats were determined. In the initial cytozol in elution with buffer of low ionic strength estrogenic uterine receptors were presented chiefly by the form with a congruent to 70A, and the receptors of the male and female kidneys--by the form with a congruent to 30 A; receptors of the liver of males and females were represented by both forms, in females the content of the form with a congruent to 70 A somewhat exceeded the content of the form with a congruent to 30 A. At the same time in the males the form with a congruent to 30 A prevailed. In elution with a buffer of a high ionic strength the receptors of all the organs under study eluated with a congruent to 20--26 A. Formation of a form with a congruent 20--26 A in case of receptors of the liver of males and the uterus was reversible under the action of a high salt concentration. Receptors of all the organs under study were capable of forming Ca2+-stabilized form with a congruent to 35 A in elution with a buffer of low ionic power and a congruent to 21-26 A in elution with a buffer of high ionic strength.

Animals↗
PubMedDate not supplied

[Certain properties of estrogen receptors in the cell nuclei of different organs of rats].

Some properties of the macromolecules, specifically binding estradiol (E2) of salt chromatin extracts of the nuclei of the kidneys, liver, prostate, testes and the uterus of rats were studied. Examination of competition of various unlabeled hormonal preparations with 3H-E2 for the binding sites demonstrated the E2-binding macromolecules of the nuclei of all the organs under study to have a high hormonal stereo-specificity. The E2-binding macromolecules of the nuclear extracts of the kidney, liver and the uterus were sensitive to the action of pronase. In sedimentation with ammonium sulfate of proteins from the 0.3 M NaCl extracts of the nuclei of the kidneys and liver, but not of the uterus, the supernatent fraction of the salt-treated extracts showed an additional (in comparison with control) specifically E2-binding macromolecule activity, sensitive to the action of pronase. An analogous effect of the appearance of additional binding activity could be obtained in heating of the nuclear extracts of the kidney and the liver at 60--100 degress C for 5 minutes.

Ammonium Sulfate↗
PubMedDate not supplied

[The effect of a periovulatory prolactin imbalance on prolactin receptor expression in rat ovary cell].

Using the technique of immunohistochemistry in combination with cytophotometry, we have studied the effect of periovulatory hyper- and hypoprolactinemia on the expression of prolactin receptors in various cell types of rat ovaries during early estrus. It has been shown that intense specific staining of oocytes is positively controlled by prolactin. The maximal intensity of specific staining was found in cells of the cumulus and the inner layer of granulosa cells in mature follicles; staining intensity gradually diminished towards the outer boundary cell layer. Postovulatory follicles are distinct from those mature follicles in which there was no ovulation in their more intense manifestation of prolactin receptors in cells of the inner layer and cumulus, as well as in increased positive staining (after prolactin administration) only in the granulosa layer cells closest to theca. In follicles which did not ovulate by the time of the early estrus, prolactin administration leads to a proportional growth of specific immunoreactivity in all cell layers of the granulosa. The administration of bromocryptin, an inhibitor of prolactin secretion, leading to a 10-fold decrease in prolactin level in blood, results in a twofold decrease in the intensity of specific staining of all cell layers of the granulosa in either type of follicle. Corpora lutea of the previous cycle have irregularly positioned luteocytes with weak and strong specific staining, the intensity of which is not changed in response to prolactin and diminishes slightly after the administration of bromocryptin. We conclude that the most intense changes in the content of prolactin receptors under the conditions of imbalance of this hormone during the periovulatory period are observed in those follicles where the oocyte did not ovulate by the time of early estrus.

Animals↗