Lysophosphatidic acid is detectable in human bronchoalveolar lavage fluids at baseline and increased after segmental allergen challenge.

BACKGROUND: Lysophosphatidic acid (LPA) is a biologically active lysophospholipid and a component of normal plasma. LPA binds to receptors expressed on circulating and structural lung cells and affects cell growth and activation. Whether LPA is present in the lung has not been previously reported. OBJECTIVE: To develop an assay to measure LPA in bronchoalveolar lavage (BAL) fluids, and to study the association between LPA and allergic airway inflammation. METHODS: Seventeen allergic subjects underwent bronchoscopy and segmental allergen challenge, followed 18 h later by BAL. Supernatants were analysed for LPA content using liquid chromatography and mass spectroscopy. Expression of LPA receptors on primary bronchial epithelial cells was analysed by immunolabelling, and the effects of LPA on epithelial cell barrier function was investigated by measuring transepithelial resistance. RESULTS: LPA was detectable in BAL from control lung segments, and significantly increased 18 h after allergen challenge. Polyunsaturated species of LPA were especially increased following segmental allergen challenge. LPA levels did not strongly correlate with the number or percentages of eosinophils, neutrophils of lymphocytes, whereas MIP-3alpha (CCL20) levels correlated significantly with the allergen-driven influx of lymphocytes. The levels of LPA from control sites correlated inversely with BAL protein content, suggesting that LPA promoted epithelial barrier integrity at baseline. Experiments using primary human bronchial epithelial cells confirmed that LPA tightened the epithelial cell barrier. CONCLUSION: Lysophosphatidic acid is detectable in human BAL fluids at baseline and its expression increases during allergic inflammation. LPA does not appear to be a dominant chemoattractant for eosinophils or lymphocytes during allergic airway inflammation. In the absence of ongoing inflammation, LPA may promote epithelial barrier integrity.

[Effect of pantogam on visual function and hemodynamic of eyes in patients with primary open-angle glaucoma]. / Vliianie pantogama na zritel'nye funktsii i gemodinamiku glaz bol'nykh pervichnoi otkrytougol'noi glaukomoi.

The complex therapy in patients with primary open-angle glaucoma, with normalized intraocular pressure but with declined visual functions included the use of the Russian neurometabolic preparation pantogam. The improvement of the visual function appeared as enlargement of the borders of visual fields, decreased area and sensitivity deficit (according to computer perimetric data). Doppler ultrasonography has demonstrated an increase in the mean blood velocity in the orbital vessels and a decrease in eyeball blood supply defects after pantogam therapy which is a favourable sign of a glaucomatous process. The authors consider the use of pantogam to be rational in the complex therapy of patients with glaucoma.

[Psychophysiological effects of combined administration of pantogam and potassium orotate in patients with neurotic disorders]. / Psikhofiziologicheskie éffekty kombinirovannogo primeneniia pantogama i orotata kaliia u bol'nykh s nevroticheskimi rasstroistvami.

The paper presents a complex psychophysiological analysis of the effect of a combined administration of pantogam and potassium orotate (kalii orotas) on the dynamics of cognitive function in patients with neurotic disorders. The investigation was conducted in an 8-stage consecutive cycle and employed computer-aided diagnostic system. It was established that the combined use of pantogam and potassium orotate produces a positive effect upon the dynamics of restoration of the attention and memory mechanisms in neurotic patients.

Halenaquinol, a natural cardioactive pentacyclic hydroquinone, interacts with sulfhydryls on rat brain Na(+),K(+)-ATPase.

Halenaquinol inhibited the partial reactions of ATP hydrolysis by rat brain cortex Na(+),K(+)-ATPase, such as [3H]ATP binding to the enzyme, Na(+)-dependent front-door phosphorylation from [gamma-(33)P]ATP, and also Na(+)- and K(+)-dependent E(1)<-->E(2) conformational transitions of the enzyme. Halenaquinol abolished the positive cooperativity between the Na(+)- and K(+)-binding sites on the enzyme. ATP and sulfhydryl-containing reagents (cysteine and dithiothreitol) protected the Na(+),K(+)-ATPase against inhibition. Halenaquinol can react with additional vital groups in the enzyme after blockage of certain sulfhydryl groups with 5,5'-dithio-bis-nitrobenzoic acid. Halenaquinol inhibited [3H]ouabain binding to Na(+),K(+)-ATPase under phosphorylating and non-phosphorylating conditions. Binding of fluorescein 5'-isothiocyanate to Na(+),K(+)-ATPase and intensity of fluorescence of enzyme tryptophanyl residues were decreased by halenaquinol. We suggest that interaction of halenaquinol with the essential sulfhydryls in/or near the ATP-binding site of Na(+),K(+)-ATPase resulted in a change of protein conformation and subsequent alteration of overall and partial enzymatic reactions.

The distribution of free sterols, polyhydroxysteroids and steroid glycosides in various body components of the starfish Patiria (=Asterina) pectinifera.

The distribution of free sterols, polyhydroxysteroids and steroid glycosides in different body components of the Far-eastern starfish Patiria (=Asterina) pectinifera has been studied. It was shown that free sterol fractions from aboral and oral body walls, gonads, stomach and pyloric ceca contained Delta(7) sterols with a preponderance of 5alpha-cholest-7-en-3beta-ol. All these body components had also toxic steroid oligoglycosides. However, polyhydroxysteroids and related low molecular weight steroid glycosides were found in stomach and pyloric ceca only. In pyloric ceca, the sulfated monoside 'asterosaponin' P(1) was identified as a main polar steroid, whereas 6-sodium sulfate of cholestane-3beta,4beta,6alpha,7alpha,8,15beta,16beta,26-octaol predominated in the stomach. Probable biological functions of polar steroids and free sterols in this starfish were discussed. It was suggested that some polyhydroxysteroids and related monoglycosides play the same biological role as bile alcohols and bile acids do in vertebrates.

Inhibition of membrane transport ATPases by halenaquinol, a natural cardioactive pentacyclic hydroquinone from the sponge Petrosia seriata.

Halenaquinol, a natural cardioactive pentacyclic hydroquinone from the sponge Petrosia seriata, was found to be a powerful inhibitor of the rat brainstem and of the rat brain cortex Na+, K(+)-ATPases and the rabbit muscle sarcoplasmic reticulum Ca(2+)-ATPase with I50 values of 7.0 x 10(-7), 1.3 x 10(-6) and 2.5 x 10(-6) M, respectively. Halenaquinol also inhibited K(+)-phosphatase activity of the rat brain cortex Na+, K(+)-ATPase with an I50 value of 3 x 10(-6) M. Ouabain-insensitive Mg(2+)-ATPase activity of the microsomal fraction of the rat brain cortex was weakly inhibited by halenaquinol. Inhibition was irreversible, dose- and time-dependent. Naphthohydroquinone fragment in structures of halenaquinol, related natural and model compounds was very important for an inhibiting effect.

Two different modes of inhibition of the rat brain Na+, K(+)-ATPase by triterpene glycosides, psolusosides A and B from the holothurian Psolus fabricii.

Effects of two triterpene glycosides, isolated from the holothurian Psolus fabricii, on rat brain Na+, K(+)-ATPase (Na, K-pump; EC 3.6.1.3) were investigated. Psolusosides A and B (PsA and PsB) inhibited rat brain Na+, K(+)-ATPase with I50 values of 1 x 10(-4) M and 3 x 10(-4) M, respectively. PsA significantly stimulated [3H]ATP binding to Na+, K(+)-ATPase, weakly increased [3H]ouabain binding to the enzyme, and inhibited K(+)-phosphatase activity to a smaller degree than the total reaction of ATP hydrolysis. In contrast, PsB decreased [3H]ATP binding to Na+, K(+)-ATPase, and had no effect on [3H]ouabain binding to the enzyme. K(+)-Phosphatase activity was inhibited by PsB in parallel with Na+, K(+)-ATPase activity. The fluorescence intensity of tryptophanyl residues of Na+, K(+)-ATPase was increased by PsA and decreased by PsB in a dose-dependent manner. The excimer formation of pyrene, a hydrophobic fluorescent probe, was decreased by PsA only. The different characteristics of inhibition mode for these substances were explained by peculiarities of their chemical structures and distinctive affinity to membrane cholesterol.

Stimulatory effects of starfish sapogenins (Asterias amurensis and Lethasterias nanimensis chelifera) on molluscan heart (Spisula sachalinensis).

Sapogenins from the starfish Asterias amurensis and Lethasterias nanimensis chelifera, 5 alpha-pregn-9(11)-ene-3 beta,6 alpha-diol-20-one, 5 alpha-cholest-9(11)-ene-3 beta,6 alpha-diol-23-one, 5 alpha-cholesta-9(11),24(25)-diene-3 beta,6 alpha-diol-23-one, (20E)-5 alpha-cholesta-9(11),20(22)-diene-3 beta,6 alpha-diol-23-one and 24 zeta-methyl-5 alpha-cholesta-9(11),20(22)-diene-3 beta,6 alpha-diol-23-one, stimulated the contractile force of the heart of the mollusk Spisula sachalinensis at concentration of 5 x 10(-5) M. Ouabain, a specific inhibitor of Na+,K(+)-ATPase, at concentration of 5 x 10(-5) M had no effect on this physiological model. Starfish sapogenins of the cholestane series moderately inhibited rat brain cortex Na+,K(+)-ATPase and decreased Ca2+ influx into Ehrlich carcinoma cells. In contrast, pregnane asterogenin asterone did not inhibit Na+,K(+)-ATPase and increased the influx of Ca2+ into cells. These effects were not the result of cell membrane damage, because none of the compounds tested have hemolytic activity.

[A new class of cardiotonic steroids]. / Novyi klass kardiotonicheskikh steroidov.

A series of 23-oxosteroid derivatives have been synthesized and tested for their inhibiting Na+, K(+)-dependent ATPase from rat brain in the 1 x 10(-6)-1 x 10(-4) M concentrations. Natural 23-oxogenins from sea star Asterias amurensis and synthetic monoesters showed the inhibiting activity upto 50-55%. These compounds caused heart contraction in frogs at the level of the known cardiotonic strophanthin G, and inotropic activity on isolated heart of mollusk Spisula sachalinensis.

Inhibition of rat brain Na+-K+-ATPase by triterpene glycosides from holothurians.

The effect of triterpene glycosides from holothurians on Na+-K+-ATPase of rat brain was investigated. The marine glycosides are irreversible inhibitors of the enzyme with an average I50 value of 10(-4) M. ATP had a low protective effect against inhibition. The inhibitory effect was increased by preincubation with MgCl2. There was alteration of the activation curve of Na+-K+-ATPase by NaCl and KCl in the presence of glycosides. Triterpene glycosides inhibited the K+-phosphatase activity, but to a smaller degree than the ATPase activity. Na+-K+-ATPase of pig kidney was less sensitive to the marine triterpene glycosides than the brain enzyme. The marine glycosides did not alter the specific binding of [3H]-ouabain to the Na+-K+-ATPase.

Physicochemical characteristics of interaction of toxic triterpene glycosides from holothurians with rat brain Na+-K+-ATPase.

High-angle X-ray diffraction spectra showed that triterpene glycosides form crystalline complexes with membrane cholesterol. Electron microscopy demonstrated a decreased vesicle size, of the membrane preparation from rat brain which is enriched in Na+-K+-ATPase, by the triterpene glycosides. The Arrhenius plot was linear in the presence of triterpene glycosides. The half-width of the phosphatidylcholine N-methyl proton line in proton NMR spectra was not altered in the presence of marine glycosides. The excimer formation of pyrene, a hydrophobic fluorescent probe, was significantly decreased by triterpene glycosides. The increase of tryptophanyl residue fluorescence demonstrated a change of the Na+-K+-ATPase conformation after treatment with cytotoxic glycosides.

Inhibitory characteristics of 3,5-dibromo-1-acetoxy-4-oxo-2,5-cyclohexadien-1-acetonitrile, a semisynthetic derivative of aeroplysinin-1 from sponges (Aplysinidae), on Na+ - K+-ATPase.

3,5-Dibromo-1-acetoxy-4-oxo-2,5-cyclohexadien-1-acetonitrile (dienone A) inhibited Na+ - K+-ATPase with a half-maximal inhibition concentration (I50) equal to 2.9 X 10(-6)M. Inhibition was time- and pH-dependent and complete after 20-30 min preincubation within a range of pH from 7.0 to 9.0. Kinetic evaluation of the cationic substrate activation of Na+ - K+-ATPase indicated mixed type inhibition with regard to Na+ and K+ and competitive inhibition with regard to ATP activation of the enzyme. The presence of Mg2+ caused an increased inhibition. Also, K+-p-nitrophenyl phosphatase activity was altered by dienone A and mixed type inhibition with regard to p-nitrophenyl phosphate and K+ was demonstrated. Inhibition was partially restored by repeated washing. Preincubation with sulfhydryl reagents protected the enzyme from inhibition. A significant linear correlation between reactive enzyme sulfhydryl contents [SH] and Na+ - K+-ATPase activity in the presence of varying concentrations of dienone A was observed. One of the factors causing cytotoxic activity of this compound might be its interaction with some thiol groups of the membrane-bound Na+ - K+-ATPase.

[Pituitary gonadotropic function in uterine trophoblastic tumor]. / Gonadotropnaia funktsiia gipofiza u bol'nykh s trofoblasticheskimi opukholiami matki.

A simultaneous determination of 3 gonadotropic hormones of the hypophysis (follitropin, lutronin and prolactin) using a radioimmunoassay in 33 patients with trophoblastic uterine tumors and 22 women on the 1st-8th day after normal delivery, has shown that there are not only significant differences in the nature of the secretion of hypophyseal gonadotropic hormones in pathology as compared to the normal postnatal period but also differences in different forms of trophoblastic tumors. These differences were characterized by a progressive, according to the severity of disease, independence between trophoblastic tissue function and gonadotropic function of the hypophysis. A marked suppression of follicle-stimulating function of the hypophysis after normal delivery decreased hydatidiform mole and trophoblastic tumors and was not observed in patients with chorioepithelioma of the uterus.

Effect of marine glycosides on adenosinetriphosphatase activity.

Marine glycosides from the sea cucumbers Actinopyga agassizi, Holothuria atra, Bohadschia argus, Cucumaria fraudatrix, Astichopus multifidus and Thelenota ananas inhibit both Na+-K+ ATPase and Mg2+-ATPase of rat brain in vitro. The glycoside-cholesterol complex of these compounds does not influence ATPase activity. Asterosaponins from starfishes Linckia guildingi and Linckia laevigata possess a slight inhibiting effect. The triterpene glycosides from sea cucumbers are more powerful inhibitors than steroidal glycosides from starfishes.

Inhibiting effect of cytotoxic bromine-containing compounds from sponges (Aplysinidae) on Na+ -K+-ATPase activity.

The bromine-containing compounds from sponges of the Aplysinidae family inhibit, in vitro, the Na+ -K+ -ATPase activity of the rat brain microsomal fraction. The extent of inhibition is dependent on concentration and chemical structure of the compounds. The substances containing the dienone fragment, such as 3,5-dibromo-1-hydroxy-4-oxo-2,5-cyclohexadien-1-acetamide (IV), 3,5-dibromo-1-acetoxy-4-oxo-2,5-cyclohexadien-1-acetonitrile (V) and 3,5-dibromo-1-hydroxy-4-oxo-2,5-cyclohexadien-1-ethylacetate (VI), are powerful inhibitors of Na+ -K+ -ATPase.