Interaction between steroid hormones and membranes of hepatocytes and erythrocytes

The uptake of tritiated steroid hormones and their passage through the dense layer of the plasma membranes of rat hepatocytes and rabbit ghost erythrocytes was investigated. The degree of uptake of steroid hormones by the plasma membranes diminishes in the following order: progesterone > testosterone > estrone > prednisolone > estriol. The degree of uptake of the hormones correlates with their solubility in lipids and with the resulting release of enzymes from the lysosomes. Meanwhile it shows negative correlation with the rate of passage through the dense layer of the membranes. The character of uptake of steroid hormones is independent of the role of the plasma membranes.N. I. Pirogov Second Moscow 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. 85, No. 1, pp. 31–33, January, 1978.     

Binding of prostaglandins E by plasma membranes of thyroid cells

The ability of the plasma membranes of human and bovine thyrocytes to bind prostaglandins of the E group (PGE) was investigated by the use of material from kits for the radioimmunological determination of PGE. Sites for specific binding of PGE with high and low affinity constants for prostaglandins were found to exist on the plasma membranes of human and bovine thyrocytes. Binding of PGE by the membrane is under the influence of thyrotrophin and cyclic nucleotides.Laboratory of Radiology, Kiev Research Institute of Endocrinology and Metabolism. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Gorev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 3, pp. 224–227, March, 1979.     

Correlation between antiarrhythmic activity of acyl derivatives of phenothiazine and their affinity for phospholipid membranes

Binding constants for thirteen 10-acylaminopropionyl derivatives of phenothiazine possessing antiarrhythmic activity with model phospholipid membranes were determined by the fluorescent probe method. For ten of these substances significant correlation was observed between the binding constant and antiarrhythmic activity: Activity increased with an increase in the constant; three substances, those with the highest binding constants, however, possess low activity. The results are evidence that interaction between antiarrhythmic drugs and lipids of target membranes in vivo may be an important element in the molecular mechanism of their action. Meanwhile, very high affinity for lipids may evidently lead to delocalization of the drug in the body and to a reduction in its antiarrhythmic activity.Department of Biophysics, Research Center, N. I. Pirogov Second Moscow Medical Institute. Laboratory of Pharmacology of the Cardiovascular System, Institute of Pharmacology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 311–313, September, 1977.     

Effect of estradiol on spontaneous single unit activity in the arcuate region of the rat hypothalamus at various stages of the estrous cycle

Microiontophoretic injection of estradiol into the arcuate region of the hypothalamus in the overwhelming majority of experiments enhanced single unit activity. The response was more marked in diestrus-1 and diestrus-2 than in proestrus. It is suggested that changes in the predominant response of arcuate neurons to injection of estradiol in the course of the sex cycle are determined by the level of endogenous estrogens and pituitary gonadotropic hormones in the peripheral blood.Laboratory of Physiology of the Endocrine System, Institute of Experimental Endocrinology and Hormone Chemistry, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Yudaev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 220–223, February, 1977.     

Immunohistochemical study of cardiolipin and phosphatidylinositol in mouse liver

The localization of phospholipid haptens (cardiolipin and phosphatidylinositol) in frozen and paraffin sections of mouse liver fixed in acetone and in an acetone-buffer-formalin mixture was studied by the indirect fluorescent antibodies method. Antiphospholipid sera specifically stained the plasma membranes of the hepatocytes, especially the region of the membrane facing the blood sinus. Detection of phospholipid haptens in liver sections with the aid of antiphospholipid sera depends on the method of obtaining and fixing the sections. Depending on the method of immunization, two types of antiphospholipid sera are obtained; they differ in their stability, in the possibility of isolating antibodies on lipid immunosorbents from them, and in their ability to stain liver sections.Laboratory of Immunochemistry and Diagnosis of Tumors, Oncologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Blokhin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 9, pp. 332–335, September, 1978.     

Synthesis of α-fetoprotein and albumin by human embryonic hepatocytes

Population aspects of the production of specific secreted proteins (serum albumin and -fetoprotein) were studied in cultures of hepatocytes from human embryos at 6–12 weeks of development. A method based on local hemolysis in gel using sheep's erythrocytes conjugated with antibodies against the proteins for testing, was used. The overwhelming majority of hepatocytes were shownto synthesize both proteins.Laboratory of Human Cytogenetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR. Laboratory of Immunochemistry and Diagnosis of Tumors, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of, Medical Sciences of the USSR, Moscow. (Presented, by Academician of the Academy of Medical Sciences of the USSR L.M. Shabad.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 6, pp. 711–713, June, 1977.     

The role of the adrenals in the restoration of the vital functions after clinical death

Summary The restoration of vital functions (Professor V. A. Negovskii's method) was studied following lethal desanguination in adrenalectomized cats.Several groups of animals were experimented upon: observation of the first group of animals was conducted 16–17 hours after adrenalectomy, adrenalectomy with administration of saline solution and cortisone (30 mg/kg of body weight per course), on the third —4 days after adrenalectomy with administration of saline solution and large doses of cortisone (70 mg/kg of body weight per course).The restoration of vital functions was best in adrenalectomized animals which received large doses of cortisone. The authors believe that cortisone is of value in the therapy of terminal conditions.Presented by Active Member AMN SSSR V. N. ChernigovskiiThe subject matter of this paper was presented at the conference of the Novosibirsk Medical Institute on April 10, 1958.     

On certain biological properties of mouse tumors subjected to heterotransplantation for prolonged periods of time

Summary Some biological characteristics of mouse tumor strains RSM, 298, and 180 transplanted to rats treated with cortisone were studied during 15–16 generations (over 100 days). Tumor biological characteristics were not significantly changed by heterotransplantation. Tumors grew after retransplantation on mice and did not grow on rats which were not treated with cortisone. The main character of sensitivity of mouse tumors to chemotherapeutic preparations from the groups of chlorethylamines and ethylenimine remained. Some insignificant alterations in the properties of tumors were also revealed. The author also noted some decrease of linear specificity, intensification of growth rate of heterotransplanted tumors during the series of passages and some diminution of sensitivity of tumors to chemotherapeutic preparations.(Presented by Active Member of the Akad. Med. Nauk SSSR N. N. Blokhin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 55, No. 2, pp. 91–95, February, 1963Doctor of Medical Sciences Yu. M. Vasil'ev assisted in directing the work.     

Interaction between nonachlazine and noradrenalin on a model phospholipid membrane

The binding of nonachlazine (NON), imipramine (IMI), and noradrenalin (NA) with model phospholipid membrane vesicles (liposomes) was investigated. Binding was determined by the quenching effect of these substances on a 3-methoxybenzanthrone (MBA) fluorescent probe present in the membrane. The method of calculating the parameters of binding of the substances with the membrane based on a change in intensity of fluorescence of MBA was developed. The binding constants of NON, IMI, and NA, with the membrane were (4.3±10.3)·10³ M^–1, (2.7±0.2)·10³ M^–1, and (0.7±0.15)·10³ M^–1 respectively. NON and IMI were shown to be able to compete with NA for the binding sites. These competitive interactions can be regarded as the probable mechanism of the blocking of reverse NA transport through the axonal and vesicular membranes characteristic of NON and IMI.Laboratory of Pharmacology of the Cardiovascular System, Institute of Pharmacology, Academy of Medical Sciences of the USSR. Department of Biophysics, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 9, pp. 1084–1086, September, 1976.     

Binding of LPS and LPS—LDL Complexes to Rat Hepatocytes

We studied binding of ³H-LPS toxin and LPS complexes with serum ¹²⁵I-LDL to primary culture of rat hepatocytes. Receptor binding of LPS and LDL—LPS complex was ∼50 and 77% of the total, respectively. Scatchard plot was linear in both cases. LDL and LDL—LPS complexes were inessential for LPS binding, while LDL—LPS binding was appreciably suppressed by LPS (−30%) and LDL (−65%).__________Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 139, No. 4, pp. 436–438, April, 2005     

Autoimmune response to injection of a protein preparation from bovine caudate nuclei into rabbits

The plasma membranes of bovine caudate nuclei were solubilized with the aid of Triton X-100. Membrane proteins extracted by the detergent were fractionated by chromatography on DEAE-cellulose and the affinity adsorbent suggested for separation of nicotinic cholinergic receptor protein (N-ChR) from the electric organ ofTorpedo. Immunization of rabbits with the purified protein preparation caused half of them to develop a syndrome of myasthenia type. This effect resembles the autoimmune response of the electric organ of the fish to N-ChR. The presence of an N-ChR in the caudate nuclei possessing similar antigenic determinants to the N-ChR of electric organs and skeletal muscles is postulated.Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR S. N. Golikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 12, pp. 687–690, December, 1977.     

Shortening of the prereplicative period of the mitotic cycle of hepatocytes during repeated stimulation of division

Repeated stimulation of division at a short interval (2–3 days) after the first division causes shortening of the prereplicative period of the mitotic cycle of hepatocytes in the regenerating rat liver to 9–10 h. Cells dividing a second time after one stimulation passed through the G₁ period of the second mitotic cycle in the same length of time. It is suggested that cells with the minimal duration of the prereplicative period do not pass through a period of transformation. With an increase in the time between successive stimulations of division (to 4–5 days) the duration of stay in a resting state was increased for most hepatocytes and they lost their ability to maintain a shortened prereplicative period.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. 85, No. 1, pp 64–67, January, 1978.     

Role of specific iodothyronine-binding proteins in nucleo-cytoplasmic relations of thyroid hormones in liver cells

The role of specific iodothyronine-binding proteins of hepatocytes in the nucleo-cytoplasmic relations of thyroid hormones in rats was investigated under normal conditions, after thyroidectomy, and in experimental thyrotoxicosis. The concentration of hormone-binding sites in the cell was shown to depend on the extracellular level of thyroid hormones. The important role of cytosol hormone-binding proteins in the accumulation and intracellular distribution of thyroid hormones is emphasized. Cytosol tri-iodothyronine-binding proteins were shown to play no part in penetration of the hormone into the nucleus. The tri-iodothyronine level in the nuclei was directly dependent on the concentration of receptor proteins in them and the degree of occupancy of the acceptor sites in the receptors themselves.Institute of Biochemistry, Academy of Sciences of the Uzbek SSR, Tashkent. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Yudaev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 1, pp. 17–19, January, 1977.     

Tityusγ toxin,a high affinity effector of the Na+ channel in muscle,with a selectivity for channels in the surface membrane

Toxin from the venom ofTityus serrulatus scorpion produces a partial block of the surface Na⁺ channel in frog muscle. This block occurs with no change in the voltage-dependence or in the kinetics of the remaining surface Na⁺ current. The partial blockade of Na⁺ channel activity occurs with no change in tubular Na⁺ currents nor in twitch tension. The maximum effect of the toxin is attained at concentrations as low as 3×10^–10 M. Hyperpolarization to potentials more negative than the resting potential (E=–90 mV) reduces or abolishes the effect of the toxin.Radioiodinated toxin binds to frog muscle membranes with a very high affinity corresponding to a dissociation constant of about 1×10^–11 M. Data obtained with both rabbit and frog muscle indicate that toxin is specific for Na⁺ channels in surface membranes. Toxin does not seem to bind to Na⁺ channels in T-tubule membranes. The biochemical data are in good agreement with electrophysiological studies and data on contraction. There is oneTityus toxin binding site per tetrodotoxin binding site in surface membranes. Competition experiments have confirmed thatTityus toxin binds to a new toxin receptor site on the Na⁺ channel structure. This site is the same that the toxin II fromCentruroides suffusus binding site, but this toxin has 100 times less affinity for the Na⁺ channel thanTityus toxin.     

Glucagon receptors along the nephron: [125I]glucagon binding in rat tubules

Binding of [¹²⁵I]glucagon was measured in microdissected pieces of tubules from the rat nephron. Specific glucagon binding sites were found only in nephron segments containing a glucagon-sensititive adenylate cyclase activity. At 7.5 nM labelled hormone, higher levels of specific binding (16–27×10^–18 mol mm^–1) were found in the thick ascending limb of the Henle's loop and in the distal convoluted tubule and lower binding levels (2–5×10^–18 mol mm^–) in the collecting tubule whereas specific binding could not be detected in the proximal tubule and in the thin segments of the Henle's loop. In the medullary thick ascending limb, Scatchard analysis of specific [¹²⁵I]glucagon binding indicated an apparent equilibrium dissociation constant of 2.4 nM. The stereospecificity of binding sites in medullary thick ascending limbs and medullary collecting tubules, was assessed by competition experiments using unlabelled glucagon, enteroglucagon and unrelated hormones (vasopressin, calcitonin, parathyroid hormone and insulin); in both segments, glucagon was more active than enteroglucagon in displacing labelled glucagon from its tubular binding sites, whereas all other hormones tested were inactive. These results indicate that tubule binding sites might be the physiological receptors for glucagon involved in adenylate cyclase activation.Abbreviations PCT proximal convoluted tubule - TDL thin descending limb - TAL thin ascending limb - MAL medullary thick ascending limb - CAL cortical ascending limb - DCT distal convoluted tubule - CCT cortical collecting tubule - MCT medullary collecting tubule     

Effect of allergic processes of immediate and delayed types on the intensity of cortisol metabolism in the guinea pig liver

The intensity of cortisol metabolism was studied during perfusion of the liver in situ with solutions containing different concentrations of cortisol. Under these circumstances metabolism was shown to take place chiefly in the direction of cortisone formation. With an increase in the cortisol concentration in the perfusion fluid the intensity of its metabolism in the liver tissue also increased. During anaphylactic changes in the liver tissue the intensity of conversion of cortisol into cortisone was reduced, indicating a disturbance of the oxidation of cortisol. In experimental allergic encephalomyelitis the intensity of cortisol metabolism also was reduced.Department of General Pathology, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 981–984, August, 1976.     

Synthesis of α-fetoproteinin vitro by human hepatocytes,singly and in microcolonies

By a combination of microelectrophoresis and precipitation in polyacrylamide gel, -fetoprotein (-FP) produced by single hepatocytes and by microcolonies of hepatocytes was determined. Liver cells from 6–13-week-old human fetuses were cultivatedin vitro for 2–5 days. -FP was found to be produced in amounts of between 70 and 800 pg per cell by 23 of 28 single hepatocytes and by 89 of 91 microcolonies consisting of 2 to 35 cellsLaboratory of Immunochemistry and Diagnosis of Tumors, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR. Laboratory of Human Cytogenetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR L. M. Shabad.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 4, pp. 481–484, April, 1977.     

Testosterone treatment of men with idiopathic hemochromatosis

Summary Patients with chronic liver disease usually exhibit low plasma levels of testosterone with loss of libido and potency; this is also valid in male patients suffering from idiopathic hemochromatosis (IHC), in whom nowadays the diagnosis is made at an earlier age. Therefore, the effect of testosterone treatment was studied in 10 patients with IHC. After the application of 250 mg testosterone enanthate i.m., the plasma testosterone (from 2.4±1.9 to 20.1±7.4 ng/ml) and estradiol (from 17.4±6.3 to 38.5±14.2 pg/ml) levels increased significantly. The rise of estradiol was in the range of controls and smaller than reported in other chronic liver diseases. In a long-term study, 250 mg testosterone enanthate was given 4-weekly for 33–96 months to 5 patients with IHC. General well-being, libido, and potency recovered almost immediately. Over a treatment period of 27.3 patient years, symptoms of hyperestrogenism (gynecomastia) or (portal vein) thrombosis were not seen, both of which had been described in patients with alcoholic liver cirrhosis. There was no deterioration of liver function. The effect of testosterone treatment on the patients' well-being and plasma hormone concentrations remained unchanged over the whole period of testosterone treatment. Thus, in male patients with IHC and lowered plasma testosterone, treatment with testosterone enanthate may be instituted. Because of the positive effects on general well-being, liver regeneration capacity, and potency, testosterone should especially be administered to younger subjects suffering from IHC.Abbreviations IHC idiopathic hemochromatosis - LH luteinizing hormone - SHBG sexual hormone binding globulin     

Endocrine response to intense interval exercise

Summary This investigation provides an insight into the physiological changes produced, and processes operating, during and after a typical interval exercise training regime. The role of interval exercise in the modulation of the plasma concentration of sex hormone binding globulin (SHBG) and the hormones -oestradiol, testosterone, prolactin and growth hormone was assessed. Eight trained male athletes [mean maximal oxygen uptake ( O_2max 64.3 (SD 3.8) ml·kg^–1·min^–1, mean age 31.5 (SD 4.5) years] undertook an intense interval exercise (treadmill running) protocol to exhaustion. Subjects completed an average of 15.6×1-min runs. This interval protocol produced significant increase in the plasma concentration of SHBG and all four hormones (all P<0.01) in the immediate post-test period. The plasma concentration of the hormones increased as indicated: -oestradiol (45%), testosterone (38%), prolactin (230%), growth hormone (2000%). These hormones have an established capacity to interact with components of many physiological systems and, as such, may provide a mechanism for the changes induced by intense exercise in many of these systems.     

3H-ouabain binding to human mononuclear leucocytes

Summary Specific binding of cardiac glycosides to intact human blood cells may be a suitable model for physiological or disease-induced changes in cardiac glycoside binding to human heart muscle. Since the erythrocyte contains no nucleus and has relatively few binding sites compared with heart muscle, intact mononuclear leucocytes were investigated in the present study. Using leucocyte suspensions from 34 normal subjects, 133 measurements of³H-ouabain binding were obtained.³H-Ouabain bound to one type of binding site with an affinity (K_D) of 2.8±1.2 × 10^–9 M, similar to that of human heart muscle. Association and dissociation were slow processes (k₊₁, 3.9×10⁴ M^–1 sec^–1; k_–1, 8.1×10^–5 sec^–1,n=2). The number of ouabain binding sites/leucocyte varied from 18,000 to 60,000 ( , 34,600±9,700), with no correlation with the proportion of monocytes present or with the serum K⁺-level of the donors. Large inter- and intra-individual differences in binding site number were measured which are probably a result of the heterogeneity of the cell suspension used. Thus, the ouabain binding site on human heart muscle and intact mononuclear leucocytes is probably identical. However, the number of binding sites in mixtures of mononuclear leucocytes shows large and inconsistent intraindividual variations, making these studies unsuitable for quantifying drug- or disease-induced changes in ouabain binding site number.Abbreviations Ci Curie - K_D Dissociation constant - (Na⁺+K⁺)-ATPase sodium and potassium-stimulated Adenosineriphosphatase (EC 3.6.1.3) - mM Millimolar Supported by the DFG (Er 65/4-4)