Quantitative correlation between histamine and 35S release from isolated rat mast cells due to the beta-adrenergic blocking drug K? 1124

An attempt was made to explain the mechanism of histamine release from isolated rat mast cells induced by the beta-adrenergic blocking drug K? 1124. This drug at the highest concentration used released 12 times more histamine than most other investigated beta-blockers. The release of histamine with K? 1124 was dose and temperature dependent. The maximal histamine release was at pH 8 and in the absence of calcium ions. Increased calcium concentration decreased histamine release significantly. The effect of K? 1124 on histamine release from mast cells was inhibited only by cocaine and 2,4-dinitrophenol; other metabolic inhibitors were ineffective. The histamine release due to K? 1124 was not followed by an equal release of 35S. Isoprenaline in equimolar concentration decreased histamine release induced by K? 1124 significantly. The release of 35S-labelled granules was decreased or blocked by isoprenaline.     

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.     

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.     

Beta-adrenoceptor blocking drugs and calcium transport in isolated rat mast cells

The beta-adrenoceptor blocking (BAB) drugs exaprolol (EXA), metipranolol (MET) and propranolol (PRO) inhibited histamine liberation and degranulation from isolated rat mast cells stimulated with the calcium ionophore A23187. MET was the most and EXA the least active. Atenolol (ATE) had no effect. Inhibition by BAB drugs of secretion induced with A23187 was not accompanied by any change in 45Ca uptake. On the other hand, EXA, MET and PRO significantly decreased 45Ca uptake by mast cells stimulated with 48/80. The effect of BAB drugs on inhibition of A23187-induced secretion from isolated mast cells was dependent on the lipid solubility of the studied drugs.     

Analysis of the adverse effects of drugs at the cellular and subcellular levels]

A release of histamine after the lipophilic betablockers exaprolol and propranolol correlates with their capability of displacing the bound membrane Ca2+ and increasing the disorder of phospholipidic membranes of the isolated mast cells. Electron microscopy confirmed intracellular displacement of histamine from granules of mast cells after exaprolol without marked structural changes on the plasmatic membrane. Hydrophilic and selective atenolol, which does not possess a histamine-liberating effect, decreases spontaneous transfer of the intracellular calcium, decreases the disorder of the mast-cell membranes, and together with exaprolol and propranolol inhibits, in dose-dependence way, the gain of extracellular histamine in cells. The inhibitory effect of EDTA, tetrodotoxine and suramine on histamine release after exaprolol explains the non-receptor mechanism of exaprolol effect, which confirms a possibility of induction of adverse effects of blockers of the beta-adrenergic receptor in the development of a bronchospasm.     

Inhibition of histamine release from dispersed human lung and tonsillar mast cells by nicardipine and nifedipine

Calcium entry blocking drugs attenuate antigen-induced bronchoconstriction in asthma which is mast cell mediated. We have investigated the effects of two calcium uptake blockers, nicardipine and nifedipine on histamine secretion from human mast cells dispersed from lung and tonsillar tissue. Mast cells were activated for secretion with anti-human IgE or calcium ionophore, A23187. Nicardipine and nifedipine caused a concentration-related inhibition of IgE-dependent histamine release from both lung (IC30 10 microM and 4.4 microM) and tonsillar (IC30 21 microM and 47 microM) mast cells. Nicardipine and nifedipine also inhibited mast cell histamine release induced by A23187 with IC30 values of 14 microM and 67 microM for lung and 15 microM and 30 microM for tonsillar mast cells. In the absence of drugs, increasing the extracellular calcium concentrations from 0.2 to 5 mM caused a concentration related increase in IgE-dependent histamine release from tonsillar mast cells. Both nicardipine and nifedipine (50 microM) displaced the concentration-effect curve to the right. Nicardipine (0.01-100 microM) caused a concentration related inhibition of rat kidney histamine methyltransferase activity used in the radioenzymatic assay of histamine (ki of 7.5-12 microM) whereas nifedipine was only a weak inhibitor. Nicardipine also interfered with the spectrofluorimetric assay after exposure to ultraviolet light. These observations demonstrate that nicardipine and nifedipine inhibit IgE-dependent and ionophore stimulated mediator secretion from human mast cells. The lack of stimulus-related specificity and the high drug concentrations required suggest that classical calcium channel blockade is not responsible for inhibition of mast cell mediator release. Furthermore, we suggest that inhibition of mast cell mediator release is unlikely to be the mechanism by which these drugs alleviate asthma.     

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.     

The inhibition of histamine release from rat peritoneal mast cells by non-steroid anti-inflammatory drugs and its reversal by calcium.

1 The non-steroid anti-inflammatory drugs, indomethacin, flufenamate and meclofenamate, inhibited the release of histamine from rat peritoneal mast cells induced by pharmacological or immunological challenge in vitro. 2 Anti-inflammatory steroids had little effect on histamine release from the mast cells. 3 Th inhibition of histamine release by the aspirin-like drugs was not prevented by incubation with glucose, unlike the inhibition of 2,4,dinitrophenol or antimycin-A. This suggests that the non-steroid anti-inflammatory compounds do not act by preventing the energy production from oxidative metabolism, required for histamine release. 4 The inhibition of the calcium ionophore A23187-induced histamine release by the aspirin-like drugs was reversed by an increase in the calcium concentration of the incubation medium. 5 The results suggest that the non-steroid anti-inflammatory compounds inhibit histamine release by actions on calcium influx into the mast cell, or on calcium mobilization or utilization within the mast cell.     

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.     

Adrenergic activity on rat pleural and peritoneal mast cells. Loss of beta-receptors during the purification procedure

Adrenergic agonists inhibit the release of histamine from rat pleural and peritoneal mast cells stimulated with compound 48/80 to a degree dependent on their beta-activity. Isoprenaline takes part in a stereoselective inhibitory action in the range 10(-7)-10(-4) M. Adrenaline induces a similar response pattern, with inhibition at higher concentrations. The response profile, but not the maximum values of inhibition, is clearly dependent on the concentration of the histamine releaser. Noradrenaline by itself is a histamine releaser, no stereoselectivity being observed. In the presence of compound 48/80 it takes part in a non-stereoselective inhibitory reaction at low concentrations. Inhibition of histamine release by isoprenaline was antagonized by 10 or 100 microM propranolol except at the highest isoprenaline concentration (1 mM). Both atenolol and propranolol nullified the inhibitory activity of noradrenaline, but not the increased histamine release it induces at higher concentrations (at least when acting in conjunction with compound 48/80). When rat mast cells are purified through Percoll, a change in their response profiles is observed. Isoprenaline and adrenaline by themselves elicit non-specific release of histamine; with compound 48/80, release is additive in the case of isoprenaline and supra-additive in the case of adrenaline. Results point to the loss of beta-adrenergic inhibitory activity after purification.     

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.     

Substance P-induced histamine release from rat peritoneal mast cells and its inhibition by antiallergic agents and calmodulin inhibitors.

Substance P-induced histamine release and Ca2+ release from the intracellular Ca store of rat peritoneal mast cells were inhibited by both antiallergic drugs and microtubule inhibiting agents. It was found that in the case of antiallergic compounds, histamine release inhibition may be intimately related to the inhibition of Ca2+ release from the intracellular store in which the microtubules play an important role. When mast cells were pretreated with either theophylline or dibutyryl cAMP, the inhibition of histamine release was closely related to the inhibition of Ca2+ release from the intracellular Ca store. Calmodulin inhibitors were also effective in inhibiting histamine release from mast cells induced by substance P. The inhibitory potencies of calmodulin inhibitors on histamine release from mast cells were closely correlated with those exerted on calmodulin activity.     

Potential anti-anaphylactic activity of clenbuterol, a beta-agonist with calcium antagonist properties

Clenbuterol 10(-8) to 10(-6) M inhibited antigen-induced histamine release from passively sensitized human lung tissue. This inhibition was not antagonized by propranolol, whereas the inhibitions observed with isoprenaline and fenoterol were reduced by propranolol. Clenbuterol also inhibited compound 48/80-induced histamine release and immunological histamine secretion from actively sensitized peritoneal rat mast cells. High concentrations of clenbuterol were required (10(-5) to 10(-3) M) and propranolol did not antagonize these inhibitions of histamine release. Isoprenaline and salbutamol did not modify the secretion from rat mast cells. The potential anti-anaphylactic activity of clenbuterol, might be partly related to its calcium antagonist property.     

The mobilization of plasma lipids by histamine in dogs

The aim of the present work was to study the mechanism of the mobilization of plasma lipids produced by histamine in the dog, in vivo. The increase of plasma lipids by histamine in vivo was suppressed by cimetidine, but not by diphenhydramine. Although, histamine increased the level of plasma adrenaline, adrenaline does not appear to contribute to the lipolysis stimulated by histamine, because propranolol and alprenolol, beta-adrenergic blocking agents, did not affect the lipolysis stimulated by histamine. From these data it is concluded that the increase of plasma lipids in vivo is not attributable to the release of adrenaline from adrenal glands by histamine, but is produced by the stimulation through H2-receptors in fat cells.     

The roles of calmodulin and protein kinase C in histamine secretion from mast cells.

The effect of a new calmodulin-antagonist, 5-iodo-1-C8, with a high selectivity for calmodulin in comparison to protein kinase C, has been investigated on histamine secretion from mast cells. It has been found to be much more sensitive for the inhibition of histamine secretion than the earlier calmodulin-antagonists, trifluoperazine and W7. The effect of four inhibitors of protein kinase C, viz. staurosporine, K252a, tamoxifen and sphingosine, has also been studied on histamine secretion from mast cells. All of them caused dose-dependent inhibition of histamine secretion induced by the three secretagogues used: antigen, compound 48/80 and the calcium ionophore A23187. K252a was tested against histamine release, induced by the stimulation of protein kinase C alone with the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) or the synthetic diacylglycerol, 1-oleoyl-2-acetyl-rac-glycerol (OAG). In both the cases K252a caused dose-dependent inhibition of histamine release. Staurosporine was also tested against TPA and was found to inhibit the release induced by it. Potentiation and inhibition (modulation) of secretagogue-induced histamine release by simultaneous protein kinase C stimulation with TPA or OAG have been demonstrated before. The potentiation and inhibition are shown to be antagonized by staurosporine. The observations point to the involvement of both calmodulin and protein kinase C in the histamine secretion process from mast cells.     

Physiological concentrations of zinc inhibit the release of histamine from human basophils and lung mast cells

We have previously shown that physiological concentrations of zinc (congruent to 7 X 10(-6) M) inhibit the release of histamine from human basophil leukocytes (Marone et al., J. Pharmacol. Exp. Ther. 217: 292, 1981). In these experiments we compared the effect of zinc chloride on the release of chemical mediators from human basophils and mast cells isolated from human lung. Preincubation (5 min, 37 degrees C) of human basophils and lung mast cells with zinc chloride (10(-6)-3 X 10(-5) M) caused dose-related inhibition of histamine and peptide leukotriene C4 (LTC4) release induced by anti-IgE. Increase Ca2+ concentrations (0.3 to 6 mM) in the extracellular medium completely reversed the inhibitory effect of zinc on anti-IgE-mediated histamine secretion. Zinc chloride was a competitive antagonist of the action of Ca2+ in histamine secretion induced by anti-IgE with a dissociation constant (Kd) of about 10(-5) M in both the basophil and mast cell systems. Thus physiological concentrations of zinc inhibit the release of histamine from human basophils and lung mast cells, presumably by blocking Ca2+ uptake induced by anti-IgE activation.     

Histamine release from rat neutrophils and mast cells as induced by ionophore--a pharmacological approach--.

A comparative study was carried out on the histamine release from rat neutrophils and mast cells by calcium ionohpore A 23 187 (Ionophore). A maximum release of histamine from neutrophils was induced by 10(-6) g/ml Ionophore and that from mast cells was 5 x 10(-6) g/ml. A fairly good correlation was found between the 45Ca incorporation into and the histamine release from both cells. The Ionophore-induced histamine release from both cells was decreased in Ca2+-free Tyrode's solution and by pretreatment with 0.05 M EDTA. Effects of different drugs on Ionophore-induced histamine release from neutrophils were similar to those seen in mast cells. Dibutyl cyclic adenosine monophosphate, theophylline, isoproterenol and prostaglandin E1 had not or only a slight inhibition on the release. The dose dependent inhibition of release was observed with disodium cromoglycate, N-(3',4'-dimethoxycinnamoyl) anthranilic acid and disodium baicalein phosphate, in experiments using both cells. Colchicine did not inhibit the reaction in these cells, however phosphatidylserine enhanced the reaction. On the other hand, the effect of concanavalin A was different in each type of cells, the release from mast cells was inhibited while the release from neutrophils was potentiated. These findings suggest the similarity of biochemical events in Ionophore-induced histamine release from neutrophils and mast cells.     

Suppression of passive cutaneous anaphylaxis by pertussis toxin, an islet-activating protein, as a result of inhibition of histamine release from mast cells

Passive cutaneous anaphylaxis (PCA) produced by antigen challenge to antibody-sensitized rats were interfered with by prior treatment with pertussis toxin, an islet-activating protein (IAP). The degree of interference was dependent on the dose and injection time of IAP; the effect of IAP developed slowly, with a maximal effect being observed 3 days later. Inhibition of PCA by IAP was associated with a decrease in histamine release from peritoneal mast cells, making it very likely that the process affected was mast cell secretion. Much less histamine was discharged in vitro, in response to certain membrane receptor (e.g. IgE receptor) stimulation, from mast cells that had been exposed to IAP than from the cells not exposed. Such an inhibitory effect of IAP was not observed when histamine release was provoked by a calcium ionophore without mediation of membrane receptors. IAP was a stronger inhibitor of histamine release than beta-adrenergic agonists. Further inhibition was produced when a beta-agonist was added to IAP-treated mast cells. The increase in the cellular content of cyclic AMP was associated with beta-agonist-induced, but not with IAP-induced, inhibition of histamine release. Thus, IAP inhibited histamine release by a mechanism in which metabolism of cyclic AMP was not directly involved.     

The ability of thapsigargin and thapsigargicin to activate cells involved in the inflammatory response.

The ability of thapsigargin and thapsigargicin to activate mast cells and leukocytes has been investigated. The thapsigargin-induced histamine release from rat peritoneal mast cells was found to be dependent on the concentration of thapsigargin, the purity of the mast cell preparations, and the number of mast cells in suspension. Thapsigargin induced histamine release from human basophil leukocytes. Thapsigargin induced beta-glucuronidase and lysozyme release from human neutrophil leukocytes. Thapsigargin caused a release of histamine from mesentery, lung, and heart mast cells of the rat, but only to a minor extent from the corresponding guinea-pig cells. Thapsigargicin induced histamine release from mesentery, lung, and heart mast cells of the rat at concentrations from 0.1 microM but provoked only a release from the corresponding guinea-pig cells in the concentration-range 0.16 to 1.6 microM. Thapsigargin increased the cytoplasmic free calcium level in intact human blood platelets at concentrations from 3.0 nM.     

Desensitization of rat mast cells: studies of some effects of anti-allergic drugs

Peritoneal mast cells from rats immunized with dinitrophenylated ovalbumin (DNP-OA) or normal cells passively sensitized with mouse anti-DNP-OA were incubated in vitro with DNP-bovine serum albumin in the absence of Ca++. This procedure induced desensitization of the cells, such that histamine release was inhibited on subsequent challenge with OA, in the presence of Ca++. The phenomenon of desensitization is supposed to involve early stages in the histamine release process and, thus, two anti-allergic drugs, disodium cromoglycate and doxantrazole, which inhibit an early event(s), were added with the Ca++ -free antigen to investigate whether they had any effect on desensitization. The inhibition of final histamine release caused by each drug and that due to desensitization were approximately additive. It was concluded that the drugs did not influence desensitization of rat mast cells. Thus, their activity was consistent with an effect on an event in the histamine release process, occurring after the generation of the activated stage believed to be responsible for desensitization.