Role of estrogens in the regulation of prolactin receptors in liver cells of female rats

Strong expression of prolactin receptors in sinusoidal domains and cytoplasmic granules of hepatocytes, which is independent of cell location in the hepatic lobule and is positively regulated by estrogens, is revealed in pubertal female rats. In estrogen-treated animals, Prolactin receptors are also exposed in the perinuclear space of some hepatocytes surrounding the central veins. Estrogens regulate the intensity of prolactin receptors expression in hepatocytes, but not the number of cells containing these receptors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 9, pp. 264–267, September, 1994 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Effect of bromocriptine on the expression of prolactin receptors in liver cells after common bile duct ligation

Immunoperoxidase method combined with cytofluorimetry showed that in contrast to hepatocytes, enhanced expression of prolactin receptors on rat cholangiocytes induced by common bile duct ligation cannot be suppressed by the prolactin secretion inhibitor bromocriptine. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 7, pp. 52–55, July, 1998     

Regeneration of the liver after partial hepatectomy with a beam of ionized plasma

Eighty guinea pigs underwent resection of the left lateral lobe of the liver, performed with a beam of ionized plasma. Morphological analysis 32 and 45 hours after partial hepatectomy revealed minor damage to the parenchyma to a depth of 300–400 μ. Autoradiography showed proliferative activity in the organ to occur in the early post-operative period. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 431–432, April, 1995 Presented by B. T. Velichkovskii, Member of the Russian Academy of Medical Sciences     

Induction of prolactin receptors in cholangiocytes of male and female rats after ligation of the common bile duct

Intense expression of prolactin receptors in cholangiocyte nuclei, nuclear membranes, and cytoplasm was demonstrated by the indirect immunoperoxidase method in intact and gonadectomied male and female rats after ligation of the common bile duct. The intensity of staining increased during cholangiocyte proliferative response to the intervention and, in contrast to hepatocytes, did not depend on animal sex and the presence of the gonads. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 1, pp. 66–70, January, 1998     

Spectrum of histone proteins and acridine orange binding by liver cell chromatin in rats at different times after partial hepatectomy

Changes in the spectrum of hepatic histones characteristic of active chromatin were observed in rats as early as 3 h after partial hepatectomy. At 6–9 h postsurgery, acridine orange binding to deproteinized chromatin areas was considerably increased. At 13 h the histone spectrum of liver cells from operated rats did not differ from that of control samples from sham-operated animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 369–371, April, 1995     

Prolactin receptor in rat bile ducts in ontogeny

Expression of prolactin receptors (PR) in the nuclei and plasma membrane of the bile duct cells is demonstrated in 1-45-day-old male and female rats with the use of indirect immunoperoxidase technique. The intensity of PR staining in the bile duct cells is not sex-dependent; it increases from the 1st day till the 45th day and disappears by the 65th day of postnatal ontogeny. The PR-specific staining of hepatocytes also increases during the first 45 days of postnatal life and becomes sex-dependent by the 65th day. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 12, pp. 669–672, December, 1996.     

Nuclear manifestation of prolactin receptors in rat hepatocytes and effect of prolactin

Ligation of the common bile duct induced intense nuclear expression of prolactin receptors in hepatocytes of male and female rats. Bromocriptin abolished this effect in female, but not in male rats. In males with ectopic pituitary transplants, nuclear and cytoplasmic manifestations of prolactin receptors in hepatocytes decreased. It is concluded that prolactin exerted a sex-dependent effect on the content of prolactin receptors in hepatocyte nuclei in rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 5, pp. 579–582, May, 1999     

Antithrombin activity after blockage of the reticuloendothelial system,splenectomy, and partial hepatectomy

After destruction or removal of part of the liver in rats the levels of antithrombins II, III, and IV fell proportionally to the extent of the interference. Destruction of the spleen led to depression, but splenectomy led to activation of antithrombin IV. Blockade of the reticuloendothelial system caused a smaller decrease in the antithrombin level than partial hepatectomy. It is suggested that the spleen produces an inhibitor of antithrombin IV.Department of Biochemistry, Zaporozh'e Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 282–284, September, 1977.     

Immunohistochemical localization of somatotropin receptors in rat liver cells. Effect of sex and hormonal status

Peculiarities of cell and tissue distribution of somatotropin receptors in liver cells of male rats and intact, pregnant, and estrogenized female rats is studied using an indirect immunohistochemical method. Experiments reveal equal and positively regulated by female hormones expression of somatotropin receptors in all hepatocytes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 10, pp. 432–435, October, 1997     

Autostimulation of prolactin receptors in adrenal cortex of guinea pigs

Prolactin injected to male guinea pigs for 7 days considerably enhanced binding of¹²⁵I-prolactin by adrenal cortex microsomes. Scatchard analysis showed that this rise is due to an increase in the receptor binding capacity but not in their affinity. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 5, pp. 548–550, May, 1997     

Adaptation of the membrane receptor apparatus of blood cells after the combined use of cryodestruction and plasma beam in experimental cirrhosis of the liver

It is shown that cryodestruction combined with resection with a plasma beam aggravates alterations of the functions of the blood cell receptor complex affected by cirrhosis, leading to hypoinsulinemia, inhibited capacity of cells to utilize glucose, a lowered metabolic activity of insulin receptors, and other changes. Three weeks after surgery the energy metabolism of the blood cells returns to the normal level, while the activity of insulin receptors and of hexokinase exceeds the control level. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 647–650, June, 1995 Presented by V. N. Yarygin, Member of the Russian Academy of Medical Sciences     

Expression of an unusual estrogen-binding protein in the liver of androgenized adult female rats during liver regeneration after carbon tetrachloride poisoning

The expression of an unusual estrogen-binding protein induced in the liver of ovariectomized adult rats by androgen was greatly reduced after their pericentrally located hepatocytes were poisoned with carbon tetrachloride, but was partially restored in the course of subsequent liver regeneration. It is suggested that the androgen program established in the periportal hepatocytes of postpubertal animals is defective. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 7, pp. 28–31, July, 1996     

Ultrastructure of rat liver cells after exhausting physical training

In rats, running of the maximum intensity caused death of some hepatocytes, an increase in the number of phagosomes in Kuppfer cells, and the emergence of connective tissue fibers in the space of Disse. Ultrastructural investigation of hepatocytes showed delayed release of bile products into bile capillaries, decrease in glycogen content, increase in the number of mitochondria (many of them were divided by the cristae), and irregular distribution of ribosomes in the rough endoplasmic reticulum. Accumulation of erythrocytes in the sinusoids, fragments of dead hepatocytes, Kuppfer cells with numerous phagosomes, and connective tissue fibers in the space of Disse were observed in rat liver after exhausting swimming. Study of hepatocyte ultrastructure revealed intense protein synthesis (as evidenced by increased number of ribosomes and unchanged mitochondria and cisternae of the rough endoplasmic reticulum), separation of cytoplasmic fragments with ribosomes into sinusoids, absence of glycogen, and lipid accumulation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 7, pp. 101–104, July, 1998     

Effects of preadministration of phenobarbital and Zyxorin on repair of rat liver parenchyma after ischemic injury

Optic and electron microscopy and morphometry demonstrate that phenobarbital aggravates postischemic injury of the liver to a greater degree than Zyxorin. Repair regeneration processes proceed in induced liver much more intensively, but are most marked after Zyxorin. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 185–188, February, 1994 Presented by Yu. I. Borodin, Member of the Russian Academy of Medical Sciences     

Effect of repeated partial hepatectomy on cell division in the regenerating rat liver

Repeated partial hepatectomy (PH), performed 24 h after a 70% PH, had the following effect on the mitotic cell cycle in the regenerating rat liver: it delayed (by about 2 h) the cells in the G₂ period, left the S period almost unchanged, and delayed the cells for 6–8 h in the G₁ period. A mock repeated operation had a similar effect. This indicates that the influence of the repeated PH on the mitotic cell cycle in the regenerating liver is due to operation stress. Additional stimulation of division by repeated PH affects the character of the regeneration process as a whole.Laboratory of Chemical Factors of Regulation of Growth and Cell Division, Institute of Biological and Medical Chemistry, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 488–491, October, 1977.     

Morphological and functional changes in the immune system during reparative regeneration of the liver

During reparative regeneration in the liver functional activity of the immune system is increased. Resection of the liver is accompanied by sharp changes in the structure of the thymus and spleen. The thymus-dependent parts of the spleen are particularly reactive. Resection of the liver in rats is accompanied by an increase in the number of stem cells in the bone marrow, as determined by the splenic colonies method. The number of colony-forming cells in the spleen of recipients of lymphocytes taken from the hepatectomized animals is significantly greater than in the spleen of recipients of lymphocytes from intact rats. If the limb is screened, ability to form endogenous colonies also is increased in partially hepatectomized rats compared with intact animals. Resection of the liver in rabbits is accompanied by a significant increase in immunological reactivity on the first to third days after the operation. The reactions of leukergia and leukocytolysis are sharply intensified during this period.Department of General Biology and Central Research Laboratory, S. M. Kirov Gor'kii Medical Institute, (Presented by Academician of the Academy of Medical Sciences of the USSR, A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 480–484, October, 1977.     

Role of prolactin in the regulation of some liver cell functions after ligation of common bile duct

In rats with ligated common bile duct, the inhibitor of prolactin secretion bromocriptine inhibited proliferation of bile ducts in males, reduced Na⁺ concentration in bile in females, and elevated blood bilirubin. In males with pituitary transplants, proliferation of bile ducts increased. It was concluded that the effects of prolactin on cholangiocyte proliferation and bile ion content after ligation of the common bile duct are sex-dependent. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny Vol. 127, No. 5, pp. 573–575, May, 1999     

Changes in rat liver mitochondria after bilateral subdiaphragmatic vagotomy

Changes in the liver mitochondria of rats after bilateral subdiaphragmatic vagotomy were studied. Two stages were distinguished in the dynamics of the response of the mitochondrial system to denervation. During the first stage (0.5–3 days after vagotomy) reversible functional disturbances due to postoperative stress took place in the mitochondria. The second stage (7–60 days after denervation) is characterized by more marked structural and functional changes with some common features with those observed in hypoxia and resulting from vagotomy itself.Department of Histology, Therapeutic Faculty, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR S. S. Debov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 4, pp. 420–422, April, 1977.     

Thermostable hepatocyte growth factor and energy metabolism in rats after partial hepatectomy

The relationship between energy metabolism in the remaining liver tissue after 60% hepatectomy and the activity of low-molecular-weight thermostable hepatocyte growth factor was studied in rats. The energy status of the liver was markedly reduced 6 h and to a greater degree 12 h after the operation, judging from the levels of ATP, ADP, AMP, and energy potential. The energy status improved (energy potential increased to 95% of the initial level) 24–72 h after the operation. This coincided with a decrease in hexokinase and phosphofructokinase activities and an increase in glucose-6-phosphate dehydrogenase and isocitrate dehydrogenase activities, indicating suppressed glycolysis and activation of the Krebs' cycle. High activity of low-molecular-weight thermostable hepatocyte growth factor was detected 24–72 h after resection of the liver (with maximum activity after 48 h). The activity of the hepatocyte growth factor increased if the range of energy potential surpassed the level sufficient for maintaining protein production, which is an energy-consuming process, but lower than the normal level. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 1, pp. 53–56, January, 1999     

Repopulation of the liver after dipin-induced damage

The alkylating preparation dipin in combination with partial hepatectomy induces genomic damage and apoptosis of hepatocytes with total replacement of parenchyma at the expense of the stem reserve cells. This model was employed to study the responses of the cell cycle to genetic damage, mechanisms of cell survival and death, and the sources of cells repopulating liver parenchyma. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 10, pp. 364–368, October, 1997