The role of membrane bound sialic acid of rat mast cells in histamine release induced by compound 48/80 and derivatives as well as calcium

Histamine release induced by compound 48/80 from rat mast cells is not dependent on extracellular Ca2+. Preincubation of mast cells with trypsin has only little effects on histamine release induced by this polycation. This work also demonstrates that histamine release induced by compound 48/80 and its analogues in the absence of extracellular Ca2+ depends on membrane bound sialic acid of the mast cell. Neuraminidase treatment of the cells in the presence of extracellular Ca2+ leads to histamine liberation. These findings suggest that sialic acid residues of the mast cell membrane constitute the site at which polycations exert their stimulatory actions of histamine liberation.     

Effect of chloroquine on isolated mast cells.

Chloroquine liberated a relatively low amount of histamine from isolated rat mast cells. In a dose-dependent way, this drug inhibited histamine liberation from mast cells stimulated with compound 48/80, A23187, concanavalin A plus phosphatidylserine (Con A + PS) and abolished histamine liberation induced by exaprolol. The degranulation was decreased in cells stimulated with 48/80, Con A + PS and exaprolol. Chloroquine significantly inhibited the formation of thromboxane B2 in mast cells stimulated with 48/80, Con A + PS and A23187. We assume that chloroquine interferes with mast cells at a plasmic membrane site as well as intracellularly.     

The effect of beta-adrenoceptor blocking drugs on histamine liberation, prostaglandin synthesis and phospholipid turnover in isolated mast cells stimulated with concanavalin A.

Exaprolol, metipranolol and propranolol decreased significantly histamine liberation, degranulation, 45Ca uptake and thromboxane B2 formation in isolated rat mast cells stimulated with concanavalin A and phosphatidylserine. Moreover, exaprolol and metipranolol decreased 32P incorporation into membrane phospholipids and metipranolol and propranolol reduced the liberation of arachidonic acid from membrane phospholipids of stimulated mast cells. Exaprolol significantly increased the arachidonic acid liberation from these cells. Possible mechanisms of interaction of beta-adrenoceptor blocking drugs with isolated mast cells are discussed.     

Histamine liberation and membrane fluidisation of mast cells exposed to the beta-adrenoceptor blocking drug propranolol

Propranolol liberates histamine from isolated mast cells and decreases the uptake of extracellular histamine in a dose-dependent way. Histamine liberation due to propranolol is accompanied by calcium displacement from intracellular storage sites. The significant increase in membrane fluidity due to propranolol is temperature dependent. The perturbation of membranes is most probably the explanation of propranolol's interaction with isolated rat mast cells which results in altered histamine transportation.     

Atenolol, exaprolol and mast cell membranes.

Lipophilic exaprolol and hydrophilic atenolol differ in their interaction with mast cell membranes. Exaprolol, as compared with atenolol, significantly decreased 32P incorporation into, but increased arachidonic acid liberation from, membrane phospholipids. Moreover, exaprolol significantly decreased phosphate incorporation in compound 48/80 and ConA-PS treated cells and decreased thromboxane formation in stimulated cells. On the other hand, atenolol decreased significantly only arachidonate liberation from stimulated mast cells. These results corroborate to some extent the effect of exaprolol and atenolol on histamine liberation which correlates with their membrane perturbing properties.     

Evidence for intracellular histamine liberation in isolated rat mast cells

The beta-adrenoceptor blocking drug exaprolol liberated histamine from isolated rat mast cells in a dose- and time-dependent way. Histamine was liberated within seconds and was not followed by a parallel granule liberation. The inhibition of histamine liberation was induced with low temperature, low pH, high concentration of Ca2+, TTD, suramin and EDTA. Subcellular distribution of 3H-exaprolol demonstrated a quantitative relationship between histamine depletion against exaprolol uptake in isolated rat mast cell granules. A nonspecific mechanism of action in the effect of exaprolol on mast cells is discussed. It is proposed that the drug acts on mast cells due to the direct and indirect ion exchange mechanism resulted in disproportion between histamine and granule liberation.     

Amine transport in isolated rat mast cells treated with betaadrenoceptor blocking drugs

Histamine and serotonin uptake in isolated rat mast cells is decreased in the presence of betaadrenoceptor blocking (BAB) drugs. Such inhibition is dose-dependent and is evidently higher for the inhibition of serotonin uptake. The most potent drugs were the highly lipophilic compounds K? 1124 and propranolol. No difference was found among the various BAB drugs in their ability to decrease histamine uptake. It is evident from the ratio between histamine and serotonin liberation on one side, to the uptake of both amines in mast cells on the other side, that with the exception of K? 1124, all investigated BAB drugs possesses higher inhibition of extracellular amine uptake in comparison with histamine and serotonin liberation. Such an effect might be a result of a primary interaction of BAB drugs with mast cells at the plasma membrane.     

Membrane perturbing activity of beta-adrenoceptor blocking drugs in isolated rat mast cells

Beta-adrenoceptor blocking (BAB) drugs perturb the membranes of isolated rat mast cells. Membrane fluidisation was temperature dependent and was determined by the liposolubility of the BAB drugs. The secretory index, evaluated as the ratio between histamine liberation and degranulation, correlated with the membrane order parameter of the mast cell membranes. The rank order of potency for mast cell activation and membrane fluidisation was: exaprolol greater than propranolol greater than metipranolol greater than atenolol.     

On the interaction of beta-adrenoceptor-blocking drugs with isolated mast cells

The interaction of beta-adrenoceptor blocking drugs (BAB drugs) with isolated mast cells resulted, according to the compound, in either a liberation of biogenic amines or an inhibition of stimulated amine release. The liberatory drugs exaprolol and K? 1124 decreased the level of cAMP, stimulated the activity of cyclic nucleotide-phosphodiesterase, decreased the incorporation of orthophosphate into membrane phospholipids and rapidly displaced calcium from binding sites in mast cells. The inhibitory drugs alprenolol, metipranolol, oxprenolol, practolol and propranolol, possessing lower liposolubility, produced opposite effects. Drugs from both groups displaced histamine from binding sites in isolated mast cell granules. The interaction of BAB drugs with mast cells is a result of non-specific rather than specific receptor interactions. Inhibitory drugs interfere with mast cells at membrane sites while liberatory drugs penetrate the membrane, thus acting both at the level of membrane and intracellularly.     

Effect of stobadine on stimulated isolated mast cells

Stobadine, an antiarrhythmic drug with antihistaminic properties, did not liberate histamine from mast cells in vitro. Compound 48/80-stimulated histamine liberation and degranulation was decreased in the presence of stobadine in a dose-dependent way. The spontaneous as well as stimulated calcium displacement in mast cells was significantly decreased by stobadine. Stobadine most probably possesses a membrane-stabilizing effect on isolated rat mast cells.     

Release of gastric histamine in patients with urticaria and food allergy

In a clinical study the participation of histamine in the allergenic response of patients with food allergy was investigated. The resting levels of gastric tissue and plasma histamines of 10 patients were slightly higher than the respective values of normal volunteers. 5 minutes after local intragastral allergenic provocation a decline of the mucosal histamine content of the allergen-treated area was noticed. Parallel investigations on the mast cell content of the stomach mucosa revealed a parallel decrease of the o-phthaldialdehyde stained cells, whereas the number of toluidine blue stained cells remained unchanged. These data are in accordance with an antigen-induced IgE-dependent liberation of the mast cell histamine stores.     

Disodiumcromoglycate and histamine liberation by cotton dust extract in the rat (author's transl)]

1. Disodiumcromoglycate (DSCG) had no influence on the microscopical appearance of rat peritoneal mast cells either by i.p. injection (2 times 10(-5) g/ml) or by i.v. infection (10 mg/kg) nor by local application (2 times 10(-5)/1 times 10(-4) g/ml). 2. A particular effect of DSCG (2 times 10(-6)/2 times 10(-5) on the tonus of guinea pig ileum or an interaction with contractor activity due to histamine (3 times 10(-8)/1 times 10(-7) g/ml) has not been established. 3. Histamine liberation from rat peritoneal mast cells by i.p. injection of aqueous cotton dust extract was not inhibited by DSCG (2 times 10(-8)/2 times 10(-7) g/ml), histamine liberation was rather increased.     

The effect of beta-adrenergic blocking drugs and inhibitors of phosphodiestease on histamine release from isolated mast cells.

Differences in the histamine liberation from isolated rat mast cells after beta-adrenergic blocking drugs were demonstrated. In equimolar concentrations histamine release was induced by K? 1124, K? 1500, K? 1560, K? 1561 and propranolol. Alprenolol, oxprenolol, propranolol, and trimepranol significantly decreased thehistamine release induced by compound 48-80. The release of granules from cells was inhibited quantitatively more than the release of histamine. This enabled us to surmise the selective effect of beta-adrenergic blocking drugs on cell membranes of mast cells. The possible mechanisms of release reaction are discussed.     

EFFECTS OF VARIOUS DRUGS ON THE OSMOTIC LYSIS OF RAT MAST CELLS

1. Rat mast cells were exposed to low osmotic pressures to produce a ‘nonspecific’ disruption of the mast cell, with release of histamine along with other intracellular contents. 2. The effect of non-steroidal anti-inflammatory drugs and various other drugs upon osmotically induced histamine release was examined. 3. Representative non-steroidal anti-inflammatory drugs indomethacin, phenylbutazone and flufenamic acid, the acidic compounds ethacrynic acid, iopanoic acid and probenecid, and the local anaesthetic lignocaine, all caused a dose-dependent facilitation of osmotically induced histamine release compared to controls. All drugs were active at 0.1 mmol/1. 4. The previously observed inhibition of compound 48/80 and the antigen-induced histamine release from rat mast cells by similar concentrations of the drugs used in the present study are unlikely to be due to mast cell plasma membrane stabilization.     

System of pharmacologic control of histamine release by mast cells on exposure to different agents

A scheme has been devised that makes it possible to assess a specific mechanism of action of any histamine-releasing agent. The scheme suggests a switch off of different stages of histamine secretion--interaction of a histamine liberator with surface cell receptors, entry of Ca2+ into the cell, temperature- and energy-dependent stages of histamine liberation, a stage that depends on microtubules, a system regulating histamine liberation with cyclic nucleotides. The scheme was made use of in clarification of the mechanism of histamine liberation on exposure of the mast cell to a specific antigen, to different doses of heavy metal salts, prednisolone and alkylating cross-binding agents.     

The inhibition of mast cell damage and histamine release in anaphylaxis by pyridine and diphosphopyridine nucleotidase inhibitors. Comparison with compound 48/80

In rats and guinea-pigs both mast cell damage and histamine release in anaphylaxis were inhibited by pyridine, nicotinamide, diethylnicotinamide, nicotinic acid, isonicotinic acid and isonicotinic acid hydrazide, which are known to be inhibitors of diphosphopyridine nucleotidases. On the other hand these compounds potentiated histamine release and mast cell damage by compound 48/80 in guinea-pigs although inhibiting the same phenomena in rats. The relationship of these findings with the mechanism of histamine liberation in anaphylaxis is discussed.     

The action of local anaesthetics on histamine release.

The effect of the local anaesthetics lidocaine, procaine and tetracaine on compound 48/80-induced histamine release from isolated rat mast cells has been investigated. They inhibited histamine release in a dose-dependent manner; at a concentration of 20 mM there was almost total inhibition of histamine release by lidocaine and about 75% inhibition by procaine. Tetracaine exerted a biphasic effect: at concentrations below 1 mM it inhibited, but at concentrations above 1 mM it potentiated histamine release. The inhibitory effect of lidocaine on compound 48/80-evoked histamine release was dependent upon the time of preincubation of mast cells with this anaesthetic and it persisted after washing the cells and resuspension in a lidocaine-free medium. An increase of calcium ions antagonized the inhibitory action of lidocaine. These results can be explained by (1) blockade of membrane receptors for calcium binding which leads to a decrease in intracellular calcium concentration and (2) increase of cellular cyclic AMP content which subsequently inhibits the releasing process.     

Die Veränderungen des Serotonin- und Histamingehaltes der Blutplättchen unter dem Einfluß von Lokalanaesthetica

Zusammenfassung Blutplättchen geben unter der Einwirkung von Lokalanaesthetica in Abhängigkeit von der Dosis und der Wirkungsstärke der angewandten Lokalanaesthetica den größten Teil ihres Serotonins ab. Bei Einwirkung höherer Lokalanaesthetica-Konzentrationen kommt es auch zu einem Austritt von Histamin und ATP, der mit einer morphologischen Veränderung der Zelle einhergeht und Ausdruck einer Plättchenschädigung ist. Die von niedrigen Lokalanaesthetica-Konzentrationen bewirkte Serotoninabgabe ist vermutlich die Folge einer kompetitiven Hemmung des stoffwechselabhängigen Aufnahmemechanismus für Serotonin. Für Histamin konnte kein aktiver Transportvorgang nachgewiesen werden. Es diffundiert passiv in die Thrombocytenzelle hinein. Die Histaminaufnahme der Blutplättchen ist daher auch nicht hemmbar durch Lokalanaesthetica.

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Summary The major part of the serotonin content of rabbit blood platelets is liberated by local anesthetics. This release depends on dosis and activity of the used drugs. Using higher concentrations of local anesthetics, a release of histamine and adenosine triphosphate can also be observed, which is accompanied by morphological alterations or a damage of the platelets. The release of serotonin by lower concentrations of local anesthetics is probably due to a competitive inhibition of an uptake mechanism depending on the metabolism of platelets. A similar mechaniism does not exist with regard to histamine uptake. This amine seems to enter the platelet membrane by only passive diffusion. Therefore the uptake of histamine isn't inhibited by local anesthetics.

     

Local anesthetics (benzyl alcohol, lidocaine, procainamide) inhibit aminopyrine accumulation in isolated rat parietal cells

The present studies were designed to examine the effect of local anesthetics (benzyl alcohol, lidocaine, and procainamide) on the secretory response of parietal cells to histamine, dbcAMP, and carbachol. Studies were performed in vitro using isolated cells from rat stomachs, and acid production was determined by 14C-aminopyrine accumulation. In addition, the (H(+)-K+)-ATPase activity of microsomal vesicles isolated from parietal cells was determined. Lower concentrations of the drugs studied increased the basal aminopyrine accumulation and potentiated the secretory response of parietal cells to histamine and dbcAMP. At higher concentrations local anesthetics progressively inhibited both the basal 14C-aminopyrine accumulation and that stimulated by histamine, dbcAMP or carbachol. While a low concentration of local anesthetics increased gastric microsomal (H(+)-K+)-ATPase activity, higher concentrations inhibited enzyme activity to about 80% of those activities found in resting parietal cells. We conclude that increased aminopyrine accumulation may reflect the activation of membrane-bound enzyme(s) involved in the cAMP-dependent signal transduction pathway mediating acid secretion by parietal cells. In turn, it is possible that the inhibition of aminopyrine accumulation by local anesthetics at higher concentrations can relate to two different mechanisms: (1) the nonspecific effect of local anesthetics that causes simple proton neutralization (as weak bases), and (2) to a minor extent their inhibitory effect on proton pump activity.     

Biscoclaurine alkaloids inhibit receptor-mediated phospholipase A2 activation probably through uncoupling of a GTP-binding protein from the enzyme in rat peritoneal mast cells.

The mechanism underlying the inhibitory effect of biscoclaurine (bisbenzylisoquinoline) alkaloids on phospholipase A2 activation in the signalling system of stimulated rat peritoneal mast cells was studied. Cepharanthine, berbamine and isotetrandrine inhibited antigen- and compound 48/80-induced arachidonic acid liberation, but not diacylglycerol formation or histamine release. They had no effect on A23187-induced arachidonic acid liberation, which was prevented by p-bromophenacyl bromide, a known phospholipase A2 inhibitor, and also did not affect phospholipase A2 activity in a cell-free system including an exogenous phospholipid substrate. Each alkaloid also inhibited arachidonic acid liberation induced by guanosine 5'-O-(3-thiotriphosphate) in saponin-permeabilized mast cells, and by mastoparan or NaF plus AlCl3 intact cells. Furthermore, each alkaloid abolished the inhibitory effect of islet-activating protein on the compound 48/80-induced arachidonic acid liberation. These data suggest that these alkaloids suppress the receptor-mediated phospholipase A2 activation through, at least in part, uncoupling of a GTP-binding protein from the enzyme, rather than by affecting the enzyme directly.