Effect of endothelin-1 on DNA synthesis in tracheal epithelium and smooth muscle cells in newborn albino rats

Repeated (5-fold) intraperitoneal injections of 5×10⁻⁹ mol/kg endothelin-1 inhibited DNA synthesis in tracheal epitheliocytes and activated lipid peroxidation in the lungs of newborn rats. Endothelin-1 in a dose of 5×10⁻⁸ mol/kg stimulated proliferative activity of tracheal smooth muscle cells and intensified lipid peroxidation in the blood, which aggravated observed changes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 3, pp. 294–296, March. 2000     

Expression patterns of type II pneumocyte apical surface glycoconjugates in lung adenocarcinoma cells

 Monoclonal antibodies and lectins were used to examine the expression patterns of apical membrane oligosaccharide sequences specific to type II pneumocytes in atypical adenomatous hyperplasia (AAH) and lung cancer. Atypical cells of AAH and papillary adenocarcinoma cells expressed abundant sialyl Thomsen-Friedenreich (TF) antigen: this was not observed in acinar adenocarcinoma, bronchioloalveolar carcinoma with mucin production or squamous cell carcinoma. Sialyl Tn antigens was also detected on a few cells in AAH and papillary adenocarcinomas. Asialo TF and Tn antigen were not observed on the surface of carcinoma cells of any type. Alpha(α)2,3-linked sialic acids predominated in type II pneumocyte, AAH and papillary adenocarcinoma, whereas ciliated columnar cells expressed α2,6-linked sialic acids. Lewis^x and sialyl Lewis^x antigens capped the TF antigen in both O- and N-linked side chains on the surface of AAH and papillary adenocarcinoma cells, but were not expressed by type II pneumocytes. The findings demonstrate that papillary adenocarcinoma cells resemble type II pneumocytes in that they express abundant sialyl TF surface antigen, but they also express TF-related antigens not found in type II pneumocytes. Apical surface glycoconjugates of AAH have structural characteristics shared by both type II pneumocytes and papillary adenocarcinoma cells. Received: 6 July 1998 / Accepted: 25 September 1998     

Enhanced adhesion of endothelial cells onto a polypropylene hollow-fiber membrane by plasma discharge treatment and high inoculum cell density

The effect of plasma discharge treatment of a microporous polypropylene hollow-fiber membrane commonly used for gas exchange in a conventional artificial lung on the adhesion of endothelial cells was investigated with the aim of constructing a hybrid artificial lung bearing endothelial cells on the membrane. The initial adhesion density and growth rate of the cells on the membrane were markedly increased following plasma discharge treatment (13.56 MHz, 30W) of the membrane for 5 to 20 min in the presence of 0.05 mmHg of various gases, such as ammonia, oxygen, and water vapor. Treatment of the membrane with ammonia for 5 min resulted in the highest increase in the cell adhesion density on 5 days from 1.4×10² to 2.0×10³ cells/cm², and the cell density reached 5.0×10³ cells/cm² after cultivation for 14 days. Increasing the inoculum cell concentration from 3.3×10⁵ to 3.2×10⁶ cells/ml resulted in an initial cell adhesion of 0.9×10⁵ cells/cm², even after 1 day. It was observed under a microscope that the cells were distributed uniformly to cover almost all of the surface area of the membrane. After the plasma discharge treatment, the permeability of the membrane to water increased to 9% of that of a polyethylene hollow fiber having pore diameters larger than 0.4 μm.     

Histidine increases β-adrenoreactivity of myocardium in frogs

Histidine (3×10⁻⁵ g/ml) had no effect on contractility and chronoinotropic relationship in frog myocardium, but rapidly and reversibly increased myocardial β-adrenoreactivity (increased myocardial response to 7×10⁻⁸, 3×10⁻⁷, and 4×10⁻⁷ g/ml epinephrine) and potentiated the positive effect of epinephrine (7×10⁻⁸, 3×10⁻⁷ g/ml) on chronoinotropic relationships in the myocardium. Histidine is considered to be a component of endogenous sensitizer of β-adrenoceptors in human blood modulating the function of cardiomyocytes. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 138, No. 8, pp. 144–147, August, 2004     

Roles of tyrosine kinase in insulin action on cell volume of fetal rat type II pneumocyte

The aim of the present study was to investigate the roles of tyrosine kinase (TK) in the insulin action on cell volume in fetal rat (20-day gestational age) type II pneumocyte. Insulin (100 nmol/l) increased cell volume, and this insulin (100 nmol/l) action was completely blocked by 50 μmol/l bumetanide (BMT) and 10 μmol/l amiloride (AML). This observation indicates that 100 nmol/l insulin activates BMT-sensitive Na⁺/K⁺/2Cl^? cotransporter and AML-sensitive pathways. The stimulatory action of 100 nmol/l insulin on BMT-sensitive Na⁺/K⁺/2Cl^? cotransporter was completely abolished by 10 μmol/l lavendustin A (LAV-A, an inhibitor of TK), however 100 nmol/l insulin could stimulate AML-sensitive pathways even in LAV-A (10 μmol/l)-treated cells. These observations indicate that the insulin (100 nmol/l) action on the BMT-sensitive Na⁺/K⁺/2Cl^? cotransporter is mediated through TK-dependent pathways, while 100 nmol/l insulin requires a TK-independent pathway to show the stimulatory action on the AML-sensitive pathways. From these observations we conclude that TK-dependent and -independent pathways are involved in the insulin (100 nmol/l) signaling in fetal rat type II pneumocyte.     

Correction effect of ATP on platelet aggregation and blood coagulation <Emphasis Type="Italic">In Vitro</Emphasis> and in the presence of circulating thrombin in rats

ATP added to plasma samples in concentrations of 5×10⁻³−5×10⁻⁵ M in vitro decreased ADP-induced platelet aggregation. Platelet aggregation stimulated with thrombin under similar experimental in vitro conditions significantly decreased in the presence of 5×10⁻⁶ M ATP and tended to decrease under the influence of ATP in concentrations of 5×10⁻³ and 5×10⁻⁷−5×10⁻⁹ M ATP. When endogenous thrombin in the circulation was stimulated by intravenous infusion of tissue thromboplastin, pretreatment with ATP (4 intramuscular injections, 0.75 mg/kg) produced a correction effect and normalized disturbed anticoagulant activity and platelet aggregation. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 4, pp. 364–366, April, 2007     

EDTA-blood filtration: A positive correlation with lymphocyte number

Blood is filtered through nuclear filters with pore diameter 5 μ under a pressure of 0.1×10⁵ dyn/cm² and 0.4×10⁵ dyn/cm². Correlation analysis of the dependence of blood filterability on blood cell count and blood cell adhesiveness is performed. There is a negative correlation between the erythrocyte count and the number of adherent granulocytes. A significant positive correlation is established between blood filterability and the lymphocyte count at a pressure of 0.4×10⁵ dyn/cm² but not at a pressure of 0.1×10⁵ dyn/cm². Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 9, pp. 262–264, September, 1994 Presented by Yu. M. Lopukhin, Member of the Russian Academy of Medical Sciences     

Correlation between the content of albumin and carotenoids in human vitreous body during prenatal development

The dynamics of the content albumin and carotenoids in human fetal vitreous body during weeks 16–31 of gestation was studied. The maximum values of total albumin (1.42 mg) and carotenoids (276 ng) during the studied period were recorded on weeks 20–22. Albumin concentration peaked during week 17 (2.11×10⁻⁴ mol/liter) and carotenoids during weeks 16–17 (about 0.045×10⁻⁴ mol/liter) of prenatal development. By week 31, the concentrations and total content of albumin and carotenoids in the vitreous body decreased. The physiological role of the studied components of the vitreous body for prenatal development of human eye is discussed. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 11, pp. 522–525, November, 2007     

Temporal pattern of accelerated lung growth after tracheal occlusion in the fetal rabbit.

Tracheal occlusion in utero is a potent stimulus of fetal lung growth. We describe the early growth mechanics of fetal lungs and type II pneumocytes after tracheal ligation (TL). Fetal rabbits underwent TL at 24 days gestational age (DGA; late pseudoglandular stage; term = 31 to 33 days) and were sacrificed at time intervals ranging from 1 to 5 days after TL. Lung growth was measured by stereological volumetry and bromodeoxyuridine (BrdU) pulse labeling. Pneumocyte II population kinetics were analyzed using a combination of anti-surfactant protein A and BrdU immunohistochemistry and computer-assisted morphometry. Nonoperated littermates served as controls. TL resulted in dramatically enhanced lung growth (lung weight/body weight was 5.00 +/- 0.81% in TL versus 2.52 +/- 0.13% in controls at 29 DGA; P < 0.001, unpaired Student's t-test). Post-TL lung growth was characterized by a 3-day lag-phase typified by relative stagnation of growth, followed by distension of airspaces, increased cell proliferation, and accelerated architectural and cellular maturation by postligation days 4 and 5. During the proliferation phase, the replicative activity of type II cells was markedly increased (type II cell BrdU labeling index was 10.0 +/- 4.1% in TL versus 1.1 +/- 0.3% for controls at 29 DGA; P < 0.02), but their numerical density decreased (3.0 +/- 0.5 x 10(-3)/microm2 in TL versus 4.5 +/- 0.3 x 10(-3)/microm2 in controls at 29 DGA; P < 0.02), suggesting accelerated terminal differentiation to type I cells. In conclusion, post-TL lung development is characterized by a well defined temporal pattern of lung growth and maturation. The rabbit model lends itself well to study the regulatory mechanisms underlying accelerated fetal lung growth after TL.     

Epidermal growth factor transcription, translation, and signal transduction by rat type II pneumocytes in culture.

Epidermal growth factor (EGF) is known to induce fetal lung maturation and its receptor is present in the lungs of several species. Recently, EGF has been immunolocalized in type II pneumocytes in rat lung. We postulated that EGF is synthesized in type II pneumocytes and that, because of its position-restricted distribution within the alveolus, EGF might act as an autocrine regulator of type II pneumocyte function. Herein, we have tested the hypothesis using adult rat type II pneumocytes in primary culture. In situ hybridization, using an oligonucleotide probe corresponding to amino acid residues 1070 to 1081 of mouse EGF precursor, demonstrated the presence of EGF precursor mRNA. Upon S-200 Sephacryl gel chromatography of type II pneumocyte extracts, EGF-reactive protein eluted as a high-molecular-weight form (greater than 100 kD). EGF immunoreactivity was localized within type II pneumocytes in the periphery of groups of 10 to 15 cells in culture. The type II pneumocytes bound [125I]EGF in a specific manner, indicating the presence of EGF receptors. Scatchard plots gave an apparent affinity constant (Ka) of 1 x 10(9) liters/mol, and the number of receptors was estimated to be 4.8 x 10(11) mg protein (50 per cell). EGF receptor binding specificity was confirmed by the absence of an autoradiographic signal for cells incubated in the presence of a 100-fold excess concentration of transforming growth factor-alpha. Binding of [125I]EGF could also be downregulated 95% by incubation with 0.2 nM transforming growth factor-alpha.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lung growth response after tracheal occlusion in fetal rabbits is gestational age-dependent.

In utero tracheal occlusion (TO) is a potent stimulus of fetal lung growth, and is currently being applied in clinical trials to treat severe forms of pulmonary hypoplasia. The aim of this study was to examine the effect of timing of TO on pulmonary growth and maturation rates. Fetal rabbits (term = 31 d) were subjected to in utero tracheal clipping at 24 (late pseudoglandular stage) or 27 d of gestation (late canalicular/early terminal sac stage). Sham-operated littermates served as controls (C). Animals were killed at time intervals ranging from 1 to 6 d (early group) or 1 to 3 d (late group) after occlusion. Lung growth was measured by computerized stereologic volumetry and 5'-bromo-2'-deoxyuridine (BrdU) pulse labeling. Pneumocyte II population kinetics were analyzed using a combination of anti-surfactant protein-A and BrdU immunohistochemistry and computer-assisted morphometry. Statistical analysis was performed using unpaired Student's t test. Early TO was followed by an initial 3-d stagnation of growth and subsequently a dramatic acceleration of growth (BrdU-labeling index [LI] 10.1 +/- 0. 6% in TO versus 2.7 +/- 0.5% in C at 29 d, P < 0.001). In contrast, late TO induced an immediate and sustained moderate increase of lung growth (BrdU-LI 2.8 +/- 0.9% in TO versus 1.1 +/- 0.2% in C at 30 d, P < 0.05), associated with relatively more pronounced air-space distension. Whereas late TO caused no significant alterations in type II cell density or proliferation, early TO was followed by a marked increase in type II cell proliferation, paradoxically associated with dramatic reduction of type II cell density after 29 d. The effects of intrauterine TO on fetal lung growth and type II cell kinetics critically depend on the gestational age, and thus on the maturity of the lungs at the time of surgery. These findings have important clinical implications with respect to the timing of fetal interventions aimed at promoting lung growth. The fetal rabbit provides an invaluable model to study the mechanics and age dependency of TO-induced lung growth.     

Inwardly rectifying K+ currents of alveolar type II cells isolated from fetal guinea-pig lung: regulation by G protein- and Mg2+-dependent pathways

 K⁺ currents in alveolar type II cells, isolated from fetal guinea-pig lung, were studied using the whole-cell patch-clamp technique. Inwardly rectifying (IR) K⁺ currents were observed when cells were bathed in symmetrical KCl-rich solutions. When extracellular K⁺ was replaced by Na⁺, inward currents were greatly decreased and the zero-current potential moved from 0 mV to –69 mV, indicating high K⁺ selectivity. In recordings with an intracellular KCl-rich solution, containing 1.12 mM Mg²⁺ and 10^–8 M free Ca²⁺, IR K⁺ currents slowly diminished with time. Addition of the irreversible G protein activator, guanosine 5’-O-(3-thiotriphosphate) (GTP [γ-S]), to the intracellular solution accelerated the rate of current run-down. In experiments where the intracellular solution was Mg²⁺ free, current run-down was abolished. The rate of current run-down was found to increase with increasing free intracellular [Mg²⁺]. Raising the intracellular free [Ca²⁺] to 10^–6 M under Mg²⁺-free conditions had no effect on the K⁺ currents. Extracellular Ba²⁺ blocked the IR K⁺ currents in a concentration- and voltage-dependent manner. Tolbutamide, a blocker of ATP-sensitive K⁺ (K_ATP) channels, had no effect on the currents. The single channel underlying the whole-cell IR K⁺ currents displayed inward rectification and had a conductance of 31 pS in symmetrical KCl-rich solutions. We demonstate that mRNA coding for IRK1 is expressed in this cell preparation. Possible functions for this channel are discussed. Received: 28 June 1996 / Received after revision and accepted: 9 September 1996     

Peripheral erythrophagocytosis in two reptiles

Two cases of peripheral erythrophagocytosis in reptiles are presented. The first case was from an anorectic and depressed adult bearded dragon (Pogona vitticeps) that had a massively elevated white blood cell count (158×10⁹/l) due to an increase in circulating azurophils with approximately 12% of these cells exhibiting erythrophagia. The second case was from an adult Children’s python (Liasis childreni) with a protracted history of anorexia after an episode of respiratory tract disease. Blood from the snake demonstrated a moderate basophilia (2.3×10⁹/l) and a normal azurophil count (4.1×10⁹/l) but with approximately 66% of the azurophils containing phagocytosed erythrocytes. While the cause of the erythrophagocytosis could not be definitively identified in these cases, a leukemoid-type monocyte population in the bearded dragon resulted in a differential of myeloproliferative disease, while the Children’s python exhibited cytological features suggestive of acquired haemophagocytic syndrome.     

Peripheral blood serum from healthy donors contains antibodies against the fragment of transcribed region of ribosomal repeat

Enzyme immunoassay showed that blood serum from healthy donors contains specific high-affinity antibodies (apparent association constant ≥5×10⁹ M^–1) against a fragment of transcribed region of ribosomal DNA repeat of human serum, which are present in a free form or are bound to extracellular DNA. Preheating of the serum at 55°C and high ionic strength (1.5 M NaCl) had no effect on the interaction of antibodies with this fragment. Competitive binding assay showed that these antibodies recognize DNA epitopes, which differ from the epitopes recognized by most anti-DNA antibodies in systemic lupus erythematosus. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 9, pp. 277–281, September, 2007     

Localization of surfactant-associated protein C (SP-C) mRNA in fetal rabbit lung tissue by in situ hybridization.

Surfactant is a lipoprotein substance that is synthesized and secreted by alveolar type II epithelial cells and acts to reduce surface tension at the air-alveolar interface. SP-C is a 5,000-D molecular weight, hydrophobic, surfactant-associated protein. In the present study, we used a ribonuclease protection assay to show that SP-C mRNA is induced in rabbit fetal lung tissue early in development, increases in relative concentration as development proceeds, and is present in maximal concentration at term (31 days of gestation). We also used the technique of in situ hybridization to localize SP-C mRNA in fetal, neonatal, and adult rabbit lung tissue. SP-C mRNA was present in all of the epithelial cells of the prealveolar region of day 19 gestational age rabbit fetal lung tissue, i.e., about 7 days before the appearance of differentiated alveolar type II cells in the fetal lung tissue. By day 27 of gestation, SP-C mRNA was restricted to epithelial cells with the morphologic characteristics of alveolar type II cells. SP-C mRNA was not detected in bronchiolar epithelium at any stage of lung development. The intensity of SP-C mRNA hybridization in the prealveolar and alveolar type II epithelial cells increased as a function of gestational age and was maximal at term. The pattern of SP-C mRNA localization in neonatal and adult rabbit lung tissue was consistent with the restriction of SP-C gene expression to differentiated alveolar type II cells. Our data are suggestive that SP-C may serve some as yet unknown function early in lung development because it is present in fetal lung prealveolar epithelial cells much earlier in gestation than are differentiated, surfactant-producing alveolar type II cells.     

Dynamics of tumor growth in Brattleboro and WAG rats injected with Walker 256 carcinosarcoma cells in different doses

The peculiarities of Walker 256 tumor growth depending on the dose of transplanted cells were studied in rats differing by vasopressin production. Transplantation of 10⁵ cells does not lead to tumor development. The dose of 7×10⁵ cells induces progressively growing tumors in WAG rats, while in Brattleboro rats tumors regressed after a short period of growth. Increasing the dose to 2.8×10⁶ cells was inessential for the dynamics of tumor growth in WAG rats, but stimulated regression of tumor growth in Brattleboro rats, producing no vasopressin. This dose dependence suggests the involvement of the immune system into the dynamics of tumor growth. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 1, pp. 88–90, January, 2008     

Mechanisms for the effect of arginine-containing dermorphin analogue on proliferative processes in the gastric mucosa of albino rats

Treatment with synthetic arginine-containing dermorphin analogue sedatin (100 mg/kg, 5 intraperitoneal injections) stimulated DNA synthesis in the gastric mucosa and decreased spontaneous and induced chemiluminescence in homogenates of the stomach from albino rats. Non-arginine sedatin analogue in the same dose had little effect on DNA synthesis and free radical oxidation. Fivefold treatment with NO synthase inhibitor L-NAME (9.3×10⁻⁵ mol/kg) suppressed DNA synthesis in the gastric mucosa. Sedatin did not modulate DNA synthesis against the background of L-NAME administration. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 9, pp. 282–284, September, 2007     

Effect of Lysophosphatidylcholine on α-Adrenoreactivity of Rat Aorta Smooth Muscles

In experiments on rat aortic ring segments, lysophosphatidylcholine in concentrations of 2 × 10⁻⁶, 2 × 10⁻⁵, and 2 × 10⁻⁴ M did not suppress the tonotropic effect of phenylephrine (6 × 10⁻⁶ and 6 × 10⁻⁵ M) and in concentration of 2 × 10⁻⁵ M even potentiated it, which was noted for phenylephrine at a concentration of 6 × 10⁻⁶ M. It was concluded that the chemomodulating effect of lysophosphatidylcholine depends on the type of receptors and cells.     

Mechanisms responsible for the resistance of tracheal smooth muscle to histamine in rats

A mechanographic study of contractile responses by tracheal smooth muscle segments of rats to a histaminergic agent showed that intact segments did not respond to histamine in the concentrations used (0.01–10 μM), whereas depolarized segments responded to histamine by dose-dependent contraction which were considerably enhanced following mechanical removal of the tracheal epithelium. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 263–264, September, 1995     

Effect of low-intensity laser radiation of the red spectrum on some properties of erythrocytes in Wistar rats

Laser radiation of different power had various effects on the properties of erythrocytes. An increase in the radiation power from 2.2 to 25 mW/cm² was accompanied by a decrease in the erythrocyte sedimentation rate and an increase in erythrocyte filtration index. Radiation of 50 mW/cm² induced abnormal erythrocyte aggregation. Increasing the time of irradiation at power intensity of 2.2 mW/cm² did not potentiate its effect on the blood. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 1, pp. 12–14, January, 2008