[An androgenic program of expression of the particular estrogen-binding protein is present in male rats in all hepatocytes]. / Androgennaia programma ékspresii osobogo éstrogensviazyvaiushchego belka imeetsia u samtsov krys vo vsekh gepatotsitakh.

Radioligand and immunohistochemical analysis was used for studying the expression of an unusual estrogen-binding protein (UEBP) in the regenerated liver of male rats poisoned with CCl4. As a result of CCl4 poisoning, most hepatocytes intensely producing UEBP and located in the central part of the liver lobules are destroyed (40 to 90% of the liver parenchymal cells). Dead cells are substituted by new hepatocytes formed due to proliferation of periportal hepatocytes in which UEBP is expressed at a low level. In regenerated liver, however, a high level of UEBP expression characteristic of the control animals is restored, as well as a gradient mode of distribution of UEBP-containing cells with the maximum UEBP concentration in hepatocytes surrounding the central vein. The results obtained with animals with either intact or removed testes were similar, except that the dynamics of liver regeneration was slower in the castrated rats. These data suggest the existence in all hepatocytes of the complete androgen-related program for UEBP expression. This program is inherited by daughter cells in the absence of an inducing hormone and is similar in all cells, independently of the extent of its phenotypic expression in hepatocytes with different localization within the liver lobule.

Inheritance of androgen program of male-specific expression of unusual estrogen-binding protein by daughter hepatocytes at rat liver regeneration.

A possibility of inheritance of androgen and basic genetic programs at the level of unusual estrogen-binding protein (UEBP) by daughter hepatocytes was investigated. Liver regeneration after partial (2/3) hepatectomy or after selective poisoning of hepatocytes of the central zone of hepatic lobules with CCl4 in adult rats were used as models of total and zonal proliferation of hepatocytes, respectively. UEBP content and the pattern of its tissue expression in the course of liver regeneration were monitored by radioligand and immunocytochemical technique. In animals of all groups possessing the androgen program of UEBP expression (intact, castrated and/or hypophysectomized males, and ovariectomized females treated with androgen) UEBP content was shown to be similarly high before initiation and after completion of liver regeneration. Unlike in males, in androgenized females a transient 4-fold increase of UEBP concentration on day 4 after partial hepatectomy was observed. In animals with a basic genetic program at the level of this protein (ovariectomized females, neonatally castrated males) only trace amounts of UEBP were observed in intact as well as in regenerated liver. The data were confirmed by immunocytochemical technique. A gradient mode of distribution of UEBP-contained cells within hepatic lobules with the highest specific staining around central veins was found by immunocytochemical technique in males. Specific staining of centrolobular and periportal hepatocytes was 7- to 10-fold in intact, and 4- to 6-fold in castrated and/or hypophysectomized males. In intact females specific staining was distributed uniformly at extremely low levels similar to that in periportal hepatocytes of males. Androgen administration to ovariectomized females stimulated a significant and stable increase of UEBP content in two layers of hepatocytes surrounding the central vein. Profiles of specific staining of hepatocytes within the hepatic lobules similar to that in control animals were observed after the completion of liver regeneration of different groups of rats. The results obtained suggest all the hepatocytes to be targets for androgen programming, natural in males or experimental in females, while the extent of expression of this program depends on the position of a hepatocyte within the liver lobules and the sex of the animal.

Endocrine mechanisms for the formation of sex-related differences in hepatic estrogen receptor content and their significance for the realization of an estrogen effect on angiotensinogen blood level in rats.

The use of a modified, adequate method of quantification of estrogen receptors has permitted us to prove the existence of sex-specific peculiarities in rat liver estrogen reception and their significance for the realization of sex-dependent changes in angiotensinogen plasma level after estrogenization. Endocrine mechanisms for the formation of sex-related differences in hepatic estrogen receptor content in rats were investigated in detail. The investigation shows that androgens have negative regulatory influence on the hepatic estrogen receptor level in rats. Estrogens and adrenal and thyroid hormones do not take part in the regulation of hepatic estrogen receptor content in rats. It has been proven that the decisive role in keeping up a certain estrogen receptor concentration in hepatocytes belongs to pituitary growth hormone. It was shown for the first time that androgens are able to inhibit the stimulatory effect of growth hormone on hepatic estrogen receptors.

[Features of the formation, expression and transmission of basic genetic and androgen programs of the level of unusual estrogen-binding protein in sexually mature female rat hepatocytes under experimental conditions]. / Osobennosti formirovaniia, ékspressii i peredachi bazisnoi geneticheskoi i androgennoi programm urovnia osobogo éstrogensviazyvaiushchego belka v gepatotsitakh polovozrelykh samok krys v éksperimente.

Some features of the formation, expression and inheritance of basic genetic and androgen programs of the level of unusual estrogen-binding protein (UEBP) in mature female rat hepatocytes under experimental conditions were investigated. Liver regeneration after partial (2/3) hepatectomy of mature rats was used for generation of a new population of differentiated hepatocytes. The UEBP content was determined by radioligand technique in control liver and at 2, 4, 14 days of liver regeneration and related to the total DNA content as an indicator of cell proliferative activity. It was revealed that the basic genetic program of low UEBP level of hepatocytes of ovariectomized females was fully transferred to daughter cell during cell proliferation and characterized by a temporary elevation of its expression during initial steps of liver regeneration. It was shown that the androgen program of a high UEBP level was completely and stably formed after androgen action in hepatocytes of ovariectomized females and was fully transferred to daughter cells during hepatocyte proliferation. However experimentally formed androgen program of a high UEBP level in female hepatocytes was completely revealed only during early steps of liver regeneration (the 4th day), its expression was essentially declined after regeneration process was over.

Evidence for direct action of testosterone on rat liver cells: in vivo and in vitro induction of unusual estrogen-binding protein.

We demonstrate that on the rat liver, testosterone (T) induced differentiated functions and enhanced unusual estrogen-binding protein (UEBP) content through mechanisms dependent on cell activation by androgens, the presence of growth hormone (GH) and the hormonal status of the animal. To determine whether liver cells are a target for androgens, we measured T effects on UEBP in gonadectomized adult male and female rats in vivo and in vitro. In ovariectomized rats, T increased 8- to 9-fold UEBP levels that remained constant during 10 days. Also in vitro, using hepatocytes from ovariectomized rats, T alone increased UEBP levels 3-fold in a dose-response pattern. Combining a fixed low dose of GH with different concentrations of T increased UEBP 2-fold above T alone. Whereas GH alone had no effects in ovariectomized rats, hepatocytes were responsive to GH, in a dose dependent pattern that was abolished when T was used together with GH. On the other hand, T alone had no effect in hypophysectomized-ovariectomized animals. The latter group was rendered T responsive after the simultaneous injection of GH with T that increased UEBP content 6.6-fold in vivo. Castrated males revealed a marked responsiveness to T and GH in vivo and in vitro, when added separately or in combination. The results obtained suggest a complex regulatory system and we conclude that T acts directly on rat liver as: (1) an inducer of sex differentiation; and (2) a regulator of UEBP production in males. In addition, liver regeneration studies in castrated-hypophysectomized males revealed the UEBP phenotype in daughter cells in the absence of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of sex steroids in the formation of sex-differentiated concentrations of corticosteroid-binding globulin in rats.

The role of sex steroids in the programming of the level of serum corticosteroid-binding globulin (CBG) in the rat has been studied at different stages of ontogenesis. The CBG content in the serum of mature female rats was 2.5 times higher than that in male rats. Sexual dimorphism of CBG content was absent in immature animals of 3-4 weeks of age. Castration of mature rats led to a 40-50% increase in CBG content. The CBG concentration in mature females or castrated adult males treated with testosterone propionate (TP; 3 mg/day for 4 days) was decreased by 40-50% compared with vehicle-treated rats. Oestradiol injection (1 microgram/day for 4 days) had no influence on CBG levels in mature male and ovariectomized adult female rats. Immature rats were castrated on days 1, 7, 14, 21, 28 or 35 of age and the CBG level was determined at 10-12 weeks of age. The CBG content of rats castrated up to day 28 of age was 2.5 times higher than that in mature males and did not differ from that in mature females. The CBG content of male rats castrated on day 35 of age was the same as that of adult castrated males. The CBG level in castrated rats treated with TP (1.25 mg for days 1-3 or 300 micrograms/day for 5 days after castration at day 7 up to day 26) did not differ from that in controls (i.e. vehicle-treated rats).(ABSTRACT TRUNCATED AT 250 WORDS)

[Role of the pituitary gland in the sex differentiation of the level of corticosteroid-binding globulin in rats]. / Rol' gipofiza v polovoi differentsirovke urovnia kortikosteroid- sviazyvaiushchego globulina u krys.

A study was made of the role of hypophyseal hormones in the regulation of the sex-associated level of corticosteroid-binding globulin (CBG) in the serum of female and male rats. Pituitary body removal did not change the level of CBG in males but caused its decrease in females to the level in intact males. Ectopic transplantation of the homologous pituitary body under the renal capsule increased the level of CBG in animals of both sexes. Intermittent infusion of STH did not change CBG content in hypophysectomized female rats and lowered it in intact females. A negative effect of androgens on the studied sign did not manifest itself either against a background of hypophysectomy or hypophyseal ectopy. Corticosteroids and thyroid hormones preserved their effects with regard to the level of CBG in hypophysectomized rats.

[Regularities in androgen reception in rat liver and its role in realizing direct androgenous effects]. / Zakonomernosti retseptsii androgenov v pecheni krys i ee rol' v realizatsii priamykh androgennykh éffektov.

The content of androgen receptors (AR) in the cytosol and nuclear fractions of rat liver cells was studied by using the radioligand method. It was found that the nuclear AR content depends on the sex of animals as well as on the initial level of AR in the cytosol fraction. Elevation of AR concentration (p less than 0.05) in liver nuclei of different groups of animals was noted one hour after injection of 100 micrograms of methyltrienolone (R-1881). This elevation correlated positively with the initial level of AR in the cytosol. The accumulation of AR in liver nuclei was more pronounced in intact males than in females. A direct positive correlation between the initial level of cytosol AR and the final regulatory effect of androgens on the hepatic AR content (r = 0.955, n = 6, p less than 0.02) and on the content of the hepatic unusual estrogen-binding protein (UEBP) (r = 0.957, n = 9, p less than 0.001) were found. It is concluded that androgens induce in liver nuclei the accumulation of AR whose level correlates with that of the initial cytosolic AR. The latter reflects the efficiency of the direct effect of androgens on liver cells.

[Transmission of "hormonal memory" of a unusual estrogen-binding protein during rat hepatocyte proliferation in the process of regeneration]. / Peredacha "gormonal'noi pamiati" po osobomu éstrogensviazyvaiushchemu belku pri proliferatii kletok pecheni krys vprotsesse regeneratsii.

The content of unusual estrogen-binding protein (UEBP), the level of DNA and common protein as well as the organ mass were studied over time during regeneration of the rat liver of intact males and gonadectomized males and females. In 21 days after partial hepatectomy of males with intact testes complete restoration of the UEBP content was observed simultaneously with restoration of the DNA and protein levels and the organ mass. There was no temporary decline of the UEBP content per DNA unit at the early stages of regeneration. The UEBP content in the liver grows during regeneration with the elevation of the DNA level not only in males with intact testes but also in preliminarily castrated males. Different UEBR programs were revcaled by the 21st day of liver regeneration in preliminarily gonadectomized animals: the androgen program of the elevated UEBP content in males, and the basal genetic program of the low level of UEBP expression in females. A conclusion has been made that the hormonal memory of a high UEBP content may be transferred to a new generation of hepatocytes in the absence of androgens. It has been assumed that androgens cause the real determination of masculinization of the EUBP content in liver cells.

[Role of hormones in maintaining the sex-differentiated level of estrogen receptors in rat liver cytosol]. / Rol' nekotorykh gormonov v podderzhanii poldifferentsirovannogo urovnia retseptorov éstrogenov v tsitozole pecheni krys.

A study was made of the endocrine mechanisms of the formation and maintenance of a sex-differentiated level of estrogen receptors (ER) in rat liver cytosol. The administration of testosterone-propionate (TP) at a dose of 3 mg for 3 days was shown to cause a significant decrease in the concentration of ER in the liver of gonadectomized animals to the level in intact male rats. In a week after the discontinuation of TP, a complete restoration of the basal level of receptors was observed. Neonatal and prepubertal administration of TP to gonadectomized male rats at early stages of ontogenesis made no effect on the level of ER in the liver cytosol of these animals at the age of 12-14 weeks. The removal of the adrenal and thyroid glands produced no changes in the level of ER in the liver of rats of both sexes. Hypophysectomy in rats resulted even on the 1st day in a decrease in ER concentration in the liver of male and female animals to the same basal level which later on remained unchanged. Ectopic transplantation of a homologous hypophysis and human STH administration led to a significant rise of the level of ER in hypophysectomized animals. TP inhibited a stimulating effect of STH in rats with the removed hypophysis.

[The characteristics of the programming action of androgens on the formation of sexual dimorphism in the level of corticosteroid-binding globulin in rats]. / Osobennosti programmiruiushchego deistviia androgenov na formirovanie polovogo dimorfizma urovnia kortikosteroidsviazyvaiushchego globulina u krys.

The role of sex steroids in the programming of the level of serum corticosteroid binding globulin (CBG) of male and female rats has been studied at different stages of ontogenesis. It was shown that castration of adult males lead to the increase of the level of CBG, but not to the elimination of sex differences. Gonadectomy of males up to 28th day of postnatal life results in complete feminization of the CBG content in these animals at the age of 10-12 weeks. The castration after 35th day of life does not prevent the formation of the male phenotype of CBG content. The results of administration of testosterone-propionate (TP) to castrated males at different periods of ontogenesis suggests that the sensitivity to irreversible negative action of androgens appears after 28th day of life and disappears after the puberty. It was concluded that short period of ontogenesis from 29th to 35th days of life is critical for the realization of the irreversible masculinization of CBG level upon the influence of androgens in the physiological conditions. It was found that injections of both synthetic estrogens diethylstilbestrol or TP in the sensitive period of ontogenesis lead to the expression of male phenotype of CBG level in a similar fashion.

[Role of corticosteroids in the regulation of the sex-differentiated level of corticosteroid-binding globulin in rats]. / Rol' kortikosteroidov v reguliatsii differentsirovannogo po polu urovnia kortikosteroidsviazyvaiushchego globulina u krys.

A study was made of the role of the adrenal cortex in the formation and modulation of the level of corticosteroid-binding globulin (CBG) in the serum of male and female rats. Corticosteroids were shown to be potent negative regulators of a CBG level in rats, the level of this protein being more sensitive to the action of these hormones in male rats than in females. Adrenalectomy in mature as well as in prepubertal rats did not level down sex differences in the level of CBG. A study of possible interdependent influence of corticosteroids and sex hormones on the level of CBG has shown that adrenocortical hormones produce an independent direct effect of the level of CBG. Producing a negative effect on the level of CBG, corticosteroids are involved in the modulation of sex dimorphism of the level of this protein in rats, enhancing sex differentiation of the CBG level in males and weakening it in female rats.

[The cellular localization of the unusual estrogen-binding protein in the liver of rats under different hormonal states]. / Kletochnaia lokalizatsiia osobogo éstrogensviazyvaiushchego belka v pecheni krys pri razlichnykh gormonal'nykh sostoianiiakh.

The localization of an unusual estrogen-binding protein (UEBP) was studied in the rat liver using indirect immunoperoxidase reaction in intact rats and after different hormonal influences. The distribution of the UEBR in normal males displays a form of a gradient with the maximum near the central veins. The gradient is absent in normal females. Castration or hypophysectomy of males, or their injection with estradiol or triiodyronine leads to a decrease in the UEBP concentration, though the gradient character of its distribution is persisting. There is a stable increase in the UEBP concentration in the first two layers of cells adjacent to the central veins in the female rat liver after ovariectomy and especially in combination with androgen injections. The revealed changes in the intensity of immunoperoxidase reaction after different hormonal influences correlate with the UEBP concentration in liver studies performed by the radioligand assay.

[Sex differences in the accumulation of estrogen receptors in nuclei of liver cells and increase of angiotensinogen concentration in the blood of rats after administration of low doses of synthetic estrogens]. / Polovye razlichiia v nakoplenii éstrogennykh retseptorov v iadrakh kletok pecheni i uvelichenii kontsentratsii angiotenzinogena v plazme krovi krys pri vvedenii niznikh doz sinteticheskikh éstrogenov.

The significance of sex differences in the level of estrogen receptors (ER) in hepatocytes for direct effects of estrogens in male and female rat livers was investigated. 4-5-fold increase in ER level and 20-30%-elevation in plasma angiotensinogen (AG) occurred after a single injection of 0.5 microgram of hexestrol (HE) in female and gonadectomized male rats. In male liver, where the cytosol ER content is two fold lower than that in female rats, nuclear ER level was shown to be very low and unchanged after HE injection, plasma AG also did not change. Injection of 0.5 microgram of ethinylestradiol produced similar effect. Injection of a greater dose of estrogen caused an enhancement in plasma AG level in males. The existence of sex differences in hepatic ER level seems to cause in some conditions different response of metabolic processes in male and female rat liver after estrogenization.

[The effect of androgens and somatotropic hormone on the expression of the level of special estrogen-binding protein in the hepatocytes]. / Vliianie androgenov i somatotropnogo gormona na ékspressiiu urovnia osobogo éstrogensviazyvaiushchego belka v gepatotsitakh.

The possibility of direct androgen determination of high unusual estrogen-binding protein (UEBP) level in female rat hepatocytes to the level typical to the males was studied. The direct effect of androgen (A) on the UEBP content in hepatocytes of ovariectomized female rats was shown by estimation in vivo and on hepatocyte culture. It has been revealed that the permissive action of growth hormone (GH) is necessary for normal expression of direct androgen effect. The latter has been stable after cessation of hormone action. High concentration of GH was found to possess positive regulatory effect on the UEBP in hepatocytes of ovariectomized rats. Effect of GH quickly disappeared after hormone withdrawal and was under negative regulation by physiological concentrations of A. It was concluded that A owing to its direct action together with permissive influence of GH is capable of determining stable expression of male phenotype of the UEBP level in hepatocytes of females.

[The effect of the administration of different estrogens on the content of estrogen receptors in the cytosol and nuclear subfractions of liver cells and on the level of angiotensinogen in the blood plasma of rats]. / Vliianie vvedeniia razlichnykh éstrogenov na soderzhanie éstrogennykh retseptorov v tsitozol'noi i iadernoi subfraktsiiakh kletok pecheni i uroven' angiotenzinogena v plazme krovi krys.

The level of estrogen receptors (ER) in the cytosol and nuclear subfractions of female rat hepatocytes was studied 1 h and plasma angiotensinogen (AG) concentration 24 h after single and multiple administration of different doses of estradiol (E2) and synthetic estrogens. Synthetic weakly metabolized estrogens, used at doses corresponding to physiological concentrations of the natural female sex steroid, were shown to be much more effective than E2 in relation to ER redistribution between the cytosol and nuclear fractions of hepatocytes as well as in relation to the stimulation of AG production by the liver. Differences in the ER level in hepatocytic nuclei 1 h after single or multiple administration of the same estrogen were undetectable. An increase in a plasma AG level after a single injection of estrogens was noted after achieving a certain threshold (more than 3-fold as compared to the normal level) level of ER accumulation in hepatocytic nuclei. The sensitivity of AG production by the liver to a stimulating effect of low doses of estrogens was on the increase as a result of their repeated effect in prolonged administration and combined administration of E2 and glucocorticoids.

[17 Beta-estradiol interaction with haptoglobin and its complex with hemoglobin]. / Issledovanie vzaimodeistviia 17 beta-éstradiola s gaptoglobinom i egokompleksom s gemoglobinom.

The estradiol-binding capacity of sheep haptoglobin and its complex with hemoglobin was investigated. It was shown that in the presence of H2O2 the haptoglobin-hemoglobin complex tightly binds 17 beta-estradiol. No dissociation of the estradiol-protein complex occurs after its precipitation with trichloroacetic acid and steroid extraction with the ester. It is supposed that the 17 beta-estradiol is bound to the protein by covalent bonds; this binding is characteristic only of the haptoglobin-hemoglobin complex but not of haptoglobin alone.

[The hormonal mechanisms of the programming and regulation of liver function differentiation by sex]. / Gormonal'nye mekhanizmy programmirovaniia i reguliatsii differentsirovki funktsii pecheni po polu.

Crucial role of androgens and estrogens in programming and regulation of the sex-dependent expression of a specific estrogen-binding protein, androgenous and estrogenous receptors and corticosteroid-binding globulin, was shown. Both types of the sex steroids effects were shown to be realized in the hepatocytes through respective hormonal receptors. The realization of physiological effects of the sex hormones demands the participation of STH as a permissive factor. Some theoretical and practical aspects of the sex differentiation of the liver functions, are discussed.