Stimulated elastase release from human leukocytes: Influence of anti-asthmatic, anti-inflammatory and calcium antagonist drugsin vitro

In the present study the effects of drugs, with different modes of action, on FMLP-stimulated release of elastase from human leukocytes were investigatedin vitro. Anti-asthmatic and anti-allergic drugs were compared to well-known anti-inflammatory and anti-histamine agents. The anti-asthmatic/anti-allergic compounds azelastine, astemizole and oxatomide, and the 5-lipoxygenase inhibitor NDGA, were able to suppress the release of elastase from human leukocytes in concentrations between 10 and 100 M. NSAIDs such as indomethacin, diclofenac and piroxicam and the glucocorticoids dexamethasone and hydrocortisone showed little or no activity. The histamine H1 antagonists mepyramine and ketotifen and the calcium antagonists verapamil, nifedipine and TMB-8 were also ineffective in suppressing FMLP-induced elastase release. Reduction in elastase release by azelastine, that accumulates in lung tissue during long-term treatment in animals, may contribute to its anti-inflammatory and anti-allergic effects which are thought to be central to its use in asthma therapy.     

Oxatomide inhibits the release of chemical mediators from human lung tissues and from granulocytes

The effects of oxatomide on the release of histamine and leukotriene C4 (LTC4) from human lung fragments and granulocytes were examined and the findings compared with the effects of the antiallergic drugs ketotifen, azelastine and tranilast. Oxatomide inhibited the release of both histamine and LTC4 from human lung fragments in cases of passive sensitization with human IgE myeloma serum upon anti-epsilon stimulation. IC50 values for the release of LTC4 from human lung fragments were as follows: oxatomide, 2.35 x 10(-5) M; azelastine, 27.2 x 10(-5) M; ketotifen, 52.1 x 10(-5) M; tranilast, 62.9 x 10(-5) M. Oxatomide also inhibited the release of both histamine and LTC4 from human mixed leukocytes stimulated by the calcium ionophore A23187. IC50 values for the release of LTC4 from human mixed leukocytes were as follows: oxatomide, 1.67 x 10(-5) M; azelastine, 3.65 x 10(-5) M; ketotifen, 12.2 x 10(-5) M; tranilast, 15.1 x 10(-5) M. The effects of oxatomide on the release of LTC4 from purified human neutrophils and eosinophils were also given attention. Oxatomide inhibited the release of LTC4 from eosinophils more effectively than from neutrophils and mixed leukocytes. As there is evidence that eosinophils play an important role in the development of late asthmatic responses and/or in the aggravation of asthma, oxatomide is expected to be an effective treatment for such conditions.     

Cyclosporin A inhibits histamine release from human peripheral basophils and human skin mast cells

Cyclosporin A (CSA) is a strong immunosuppressive substance which is widely used for prevention of transplant rejection. Moreover, this compound is clinically active in different cutaneous inflammatory reactions. In the present study the effects of CSA on mediator release from activated human basophils and isolated human skin mast cells, as important effector cells of such skin diseases, were investigated. CSA exterted a dose-dependent inhibition of the IgE-mediated histamine release from both cell populations. The maximum inhibition was 64.4±9.3% and 85.8±14.2% for basophils and skin mast cells, respectively. Non-immunological histamine release induced by calcium ionophore A23817 was also inhibited. The present data suggest, therefore, that the anti-allergic properties of CSA on basophils and skin mast cells may be partially responsible for the strong anti-inflammatory effects of CSAin vivo.

     

Influences of anti-allergic drugs on superoxide generation from the hypoxanthine-xanthine oxidase system or polymorphonuclear leukocytes

The influences of anti-allergic drugs on superoxide generation from the hypoxanthine-xanthine oxidase system or polymorphonuclear leukocytes (PMN) were studied by an electron spin resonance assay using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trapper. The intensity of DMPO-OOH signal generated from the hypoxanthine-xanthine oxidase system was not influenced by the presence of azelastine, ketotifen, disodium cromoglycate, mequitazine, or methylprednisolone, but it decreased in the presence of AA-673. A kinetic study showed that the second order rate constant for reaction between AA-673 and superoxide anion at pH 7.4 was 2.9 x 10(8)M-1S-1. The relative intensity of DMPO-OOH spin adduct generated from PMN stimulated with phorbol myristate acetate (PMA) or opsonized zymosan (OZ) significantly decreased in the presence of azelastine: from the PMN-PMA system, with 10.7 microM concentration of molar concentration causing 50% reduction of the signal intensity (IC50), while from the PMN-OZ system, with 10.5 microM concentration of IC50, and also decreased in the presence of mequitazine: from the PMN-PMA system, with 10.8 microM concentration of IC50, while from the PMN-OZ system, less than 2.0 microM concentration of IC50. These results suggest that some anti-allergic drugs may have anti-inflammatory and anti-oxidative actions due to scavenging superoxide radicals or due to inhibiting superoxide production.     

Biochemical study on anti-inflammatory action of anti-allergic drugs--with regard to NADPH oxidase]

The effects of anti-allergic drugs with or without H1-receptor antagonism on the NADPH oxidase from human neutrophils in both whole-cell and fully soluble (cell-free) systems were investigated. Three anti-allergic drugs with H1-receptor antagonism, azelastine, ketotifen and oxatomide, were found to inhibit the superoxide generation of human neutrophils exposed to phorbol myristate acetate in a whole-cell system and the activation of superoxide-generating NADPH oxidase by sodium dodecyl sulfate in a cell-free system. The concentrations of three drugs required for 50% inhibition of the oxidase (IC50) were as follows: azelastin--0.7 microM in the whole-cell system and 0.5 microM in the cell-free system, ketotifen--60 microM in the whole-cell system and 6.8 microM in the cell-free system, and oxatomide--25 microM in the whole-cell system and 9.7 microM in the cell-free system. In addition, in the cell-free system, these drugs did not change the Km values for the NADPH of the oxidase. However, micromoles of tranilast, an anti-allergic drug without H1-receptor antagonism, did not inhibit neutrophil NADPH oxidase in the whole-cell and cell-free systems. The IC50 of hydrocortisone in the cell-free system was 60 microM. These results suggest that anti-allergic drugs with H1-receptor antagonism inhibit reconstitution of the solubilized membrane-bound enzyme by sodium dodecyl sulfate in cell-free systems and that they have a strong anti-inflammatory action. Anti-allergic drugs are not the drugs of first choice for asthma, but these drugs, especially basic anti-allergic drugs, should be used more frequently for the treatment of chronic asthma, infectious-typed asthma and mixed-typed asthma closely associated with acute and chronic inflammation of the airways as well as atopic asthma.     

Inhibition of allergic histamine release by azelastine and selected antiallergic drugs from rabbit leukocytes

The ability of azelastine to inhibit allergic histamine release from rabbit mixed leukocytes was studied and compared with selected antiallergic drugs. Azelastine, ketotifen, diphenhydramine, theophylline and disodium cromoglycate (DSCG) produced concentration-dependent inhibition of allergic histamine release from rabbit basophils. The concentrations inhibiting histamine release by 50% (IC50; microM) were as follows: azelastine = 4.5; ketotifen = 9.5; diphenhydramine = 18.9; theophylline = 56.9; DSCG = greater than 1,000. DSCG was added to the cells immediately prior to antigen challenge. All other drugs were preincubated for a period of 10 min prior to antigen challenge. At the IC50 level, azelastine is about 2, 4, 13 and greater than 200 times as effective as ketotifen, diphenhydramine, theophylline and DSCG, respectively. The IC50 of azelastine following 0, 10 and 30 min preincubation were 2.4, 1.9 and 3.5 microM, respectively. These observations showed: (1) azelastine is capable of acting rapidly on basophils and of inhibiting allergic histamine secretion, and (2) the prolongation of the preincubation time of azelastine up to 30 min with rabbit leukocytes did not exhibit any sign of tachyphylaxis (loss of activity). In conclusion, azelastine is a potent inhibitor of allergic histamine secretion from the leukocytes of ragweed-sensitized rabbits.     

The effects of anti-inflammatory and antiallergic drugs on the release of IL-1β and TNF-α in the human whole blood assay

Heparinized human whole blood was evaluated as a model to study the effects of various classes of anti-inflammatory drugs on IL-1β and TNF-α release from leukocytes. Human whole blood was stimulated with zymosan (1.5 mg/ml) or LPS (5 μg/ml) to induce significant cytokine release. As previously reported, the 5-lipoxygenase/cyclooxygenase (5-LO/CO) inhibitor, SKF86002 (30 μM), significantly inhibited both IL-1β and TNF-α release using either stimulus. In contrast, the cyclooxygenase (CO) inhibitors (naproxen and ibuprofen) and the lipoxygenase (5-LO) inhibitors (zileuton, L-663536 and BWA4C) did not effect IL-1β or TNF-α release/biosynthesis. Isoproterenol (β-agonist), rolipram (a PDE-IV inhibitor), and IBMX (a nonselective PDE inhibitor), significantly inhibited TNF-α but not IL-1β in the LPS model while having no effect in the zymosan model. This human whole blood assay is a unique and rapid method which can be used to identify novel inhibitors of IL-1β and TNF-α release/biosynthesis.

     

Azelastine is more potent than olopatadine n inhibiting interleukin-6 and tryptase release from human umbilical cord blood-derived cultured mast cells.

BACKGROUND: Mast cells are involved in early- and late-phase reactions by releasing vasoactive molecules, proteases, and cytokines. Certain histamine-1 receptor antagonists and other antiallergic drugs seem to inhibit the release of mediators from rat and human mast cells. OBJECTIVE: Azelastine and olopatadine are antiallergic agents present in the ophthalmic solutions azelastine hydrochloride (Optivar, Asta Medica/Muro Pharmaceuticals, Tewksbury, MA), and olopatadine hydrochloride (Patanol, Alcon Laboratories, Fort Worth, TX), respectively. We investigated the effect of these drugs on interleukin-6 (IL-6), tryptase, and histamine release from cultured human mast cells (CHMCs). METHODS: CHMCs were grown from human umbilical cord blood-derived CD34+ cells in the presence of stem cell factor and IL-6 for 14 to 16 weeks. Sensitized CHMCs were pretreated with various concentrations of azelastine or olopatadine for 5 minutes. CHMCs were then challenged with anti-immunoglobulin E, and the released mediators were quantitated. RESULTS: The greatest inhibition of mediator release was seen with 24 microM azelastine; this level of inhibition was matched with the use of 133 microM olopatadine. At this concentration, these drugs inhibited IL-6 release by 83% and 74%, tryptase release by 55% and 79%, and histamine release by 41% and 45%, respectively. Activated CHMCs were characterized by numerous filopodia that were inhibited by both drugs as shown by electron microscopy. CONCLUSIONS: These results indicate that azelastine and olopatadine can inhibit CHMCs activation and release of IL-6, tryptase, and histamine. On an equimolar basis, azelastine was a more potent inhibitor than olopatadine.     

Azelastine inhibits stimulated histamine release from human lung tissuein vitro but does not alter cyclic nucleotide content

To investigate the mechanism by which azelastine may be effective therapeutically in asthma, we studied its ability to inhibit anti-IgE- and calcium ionophore A23187-stimulated histamine release from human lung and to alter lung cyclic nucleotide levels. Significant inhibition of histamine release from both anti-IgE- and A23187-stimulated human tissue was aparent after 30 minutes preincubation of the lung tissue in azelastine. Significant inhibition of anti-IgE-stimulated histamine release was consistently seen in azelastine concentrations 5 M, and was dose dependent (r=0.71,p<0.05) with maximal mean inhibition of 53±11%. For A23187-stimulated lung tissue, consistent inhibition of histamine release was not found until we used 30 M azelastine, mean 35±11%. Inhibition in azelastine concentrations below 30 M was variable and not significant. Lung cyclic AMP and cyclic GMP content was not significantly altered by incubation of lung tissue in 100 M azelastine. We conclude that azelastine inhibits stimulated histamine release from human lung tissuein vitro but does not alter cyclic nucleotide content.Supported in part by a VA Merit Review Award and a grant from Wallace Laboratories, Division of Carter-Wallace.     

Phospholipase A2 inhibition by alkylbenzoylacrylic acids

AGN 190383 is a 5-hydroxy-2(5H)-furanone ring analog of the marine natural product manoalide. When applied topically, AGN 190383 inhibits phorbol ester induced mouse ear edema. It is a potent inhibitor of bee venom phospholipase A₂ and blocks the release of arachidonic acid from calcium ionophore A23187 stimulated human neutrophils. AGN 190383 also inhibits both hormone-operated and depolarization-dependent calcium mobilization in GH₃ cells, as well as fMLP stimulated increases in free cytosolic calcium in human PMNs. Furthermore, it is also able to block the release of the neutral protease elastase from stimulated neutrophils. The effects of AGN 190383 on arachidonic acid metabolism and leukocyte function may account, in part, for its anti-inflammatory activityin vivo.     

Inhibitory effect of anti-allergic drugs on cholinergic and non-cholinergic neurotransmissions of guinea pig bronchial muscle in vitro

To determine whether anti-allergic drugs can inhibit autonomic neurotransmission of airway smooth muscle, we studied the effect of sodium cromoglycate (SCG, Intal) and related anti-allergic drugs on electrically induced neurogenic contractions of isolated guinea pig bronchial muscle. Electrical field stimulation (8 Hz, 0.5 msec, 30 V) evoked a biphasic contraction of bronchial muscle, consisting of an initial phasic component followed by a sustained one which was mediated by cholinergic and non-cholinergic nerve stimulations, respectively. Sodium cromoglycate, tranilast, ketotifen, and azelastine at concentrations higher than 10(-6) M caused a concentration-dependent inhibition in the height of the non-cholinergically mediated contractions. The cholinergically mediated contractions were also inhibited by tranilast, ketotifen, and azelastine but not by SCG. Submaximal contractions of bronchial muscle evoked by exogenous substance P (2 X 10(-7) M) were less potently inhibited by these drugs than those by exogenous acetylcholine (2 X 10(-6) M). These results indicate that in isolated guinea pig bronchial muscle, anti-allergic drugs may inhibit non-cholinergic neurotransmission mainly by prejunctional reduction of the transmitter release and partly by postjunctional depression of the response.     

[6]-Shogaol inhibits the production of proinflammatory cytokines via regulation of NF-κB and phosphorylation of JNK in HMC-1 cells

Abstract

[6]-Shogaol is a major bioactive component of Zingiber officinale. Although [6]-shogaol has a number of pharmacological activities including antipyretic, analgesic, antitussive and anti-inflammatory effects, the specific mechanisms of its anti-allergic effects have not been studied. In this study, we present the effects of [6]-shogaol on mast cell-mediated allergic reactions in vivo and in vitro. Sprague–Dawley rats received intradermal injections of anti-DNP IgE was injected into dorsal skin sites. After 48?h, [6]-shogaol was administered orally 1?h prior to challenge with DNP-HSA in saline containing 4% Evans blue through the dorsal vein of the penis. In addition, rat peritoneal mast cells (RPMCs) were cultured and purified to investigate histamine release. In vitro, we evaluated the regulatory effects of [6]-shogaol on the level of inflammatory mediators in phorbol 12-myristate 13-acetate plus calcium ionomycin A23187-stimulated human mast cells (HMC-1). [6]-Shogaol reduced the passive cutaneous anaphylaxis reaction compared to the control group, and histamine release decreased significantly following the treatment of RPMCs with [6]-shogaol. In HMC-1 cells, [6]-shogaol inhibited the production of TNF-α, IL-6 and IL-8, as well as the activation of nuclear factor-κB (NF-κB) and phosphorylation of JNK in compound 48/80-induced HMC-1 cells. [6]-shogaol inhibited mast cell-mediated allergic reactions by inhibiting the release of histamine and the production of proinflammatory cytokines with the involvement of regulation of NF-κB and phosphorylation of JNK.     

Inhibition of IgE-mediated allergic histamine release from rat peritoneal mast cells by azelastine and selected antiallergic drugs

The ability of azelastine to inhibit IgE-mediated allergic histamine release from the peritoneal mast cells of actively sensitized rats was investigated and compared with selected antiallergic agents. Azelastine added simultaneously with the allergic stimuli (ovalbumin, OA, 10 g/ml + phosphatidylserine, PS, 10 g/ml) or preincubated with cells for 10 min prior to antigen challenge produced similar concentration-dependent inhibition of allergic histamine release. The IC_50s (M) following 10-min preincubation were as follows: azelastine = 4.8; astemizole = 86.3; ketotifen = 112.2; diphenhydramine = 133 and theophylline = 2040.3. At IC₅₀ level azelastine was about 18, 23, 28 and 425 times as effective as astemizole, ketotifen (newer histamine H₁-receptor antagonists), diphenhydramine (a traditional H₁-receptor antagonist), and theophylline (a phosphodiesterase inhibitor), respectively. Sodium cromoglycate in a concentration range or 1–1000 M (0 or 10-min preincubation) failed to exert any inhibitory effect. These data showed that among six drugs tested azelastine is the most potent inhibitor of allergic histamine release from rat peritoneal mast cells.     

Heterogeneity of calcium channels in mast cells and basophils and the possible relevance to pathophysiology of lung diseases: A review

Calcium plays a critical role in the formation and secretion of a wide variety of chemical mediators. Calcium slow-channel blockers,e.g. nifedipine and verapamil, have been shown to inhibit the synthesis of SRS (SRS-A, leukotrienes) in human and guinea pig lung tissue, thromboxane A₂ formation in rat lung and platelet activating factor in human neutrophils. Verapamil and nifedipine also prevent the release of lysosomal enzymes from rabbit and human polymorphonuclear neutrophils. Calcium-channel blockers produce variable inhibitory effects on allergic and nonallergic histamine secretion. Ca⁺⁺-entry blockers also inhibit the Ca⁺⁺ uptake (influx) into mast cells. Many of these inhibitory effects of Ca⁺⁺ antagonists are antagonized by an increased extracellular Ca⁺⁺ ion concentration. The magnitude of the inhibitory influences of Ca⁺⁺-channel blockers on allergic and nonallergic release of chemical mediators appears to depend on the cell source, species, nature and the concentration of the secretory stimuli as well as on the composition and pH of buffers and the concentration of Ca⁺⁺-entry blockers used. The data summarized in this review suggest the existence of a functional heterogeneity of Ca⁺⁺ channels in leukocytes, mast cells and basophils. Interference with the Ca⁺⁺-dependent steps involved in the formation and/or release of chemical mediators appears to be the primary mode of action for Ca⁺⁺-channel blockers in these cells.The differential effects of Ca⁺⁺ antagonists on Ca⁺⁺-dependent activation of phospholipase A₂, 5-lipoxygenase, and calmodulin (or other intracellular Ca⁺⁺-binding proteins) in different cell types (mast cells, basophils, leukocytes, lung tissue, etc.) may explain the variation of their effectiveness in inhibiting the synthesis/release of chemical mediators and antagonizing bronchoconstriction in response to diverse stimuli.During the process of hypersensitization and in immediate hypersensitivity diseases, Ca⁺⁺ homeostasis (uptake, mobilization, distribution, relocation, etc.) may be altered in leukocytes (mast cells, basophils) and lung tissues. The altered Ca⁺⁺ homeostasis could be responsible for the induction of airway hyperreactivity in asthmatics and for hyperreleasability of chemical mediators from leukocytes, mast cells and other cell types.The development of drugs (Ca⁺⁺-channel blockers, antiallergic agents) that are capable of selectively altering Ca⁺⁺-dependent functions in leukocytes (mast cells, basophils, macrophages) and lung tissue in disease staes would offer an attractive alternative and an effective therapeutic approach for obstructive respiratory diseases,e.g. allergic asthma, exercise-induced asthma and a variety of other mediator-dependent allergic disorders.     

Control of Immune Responses by Cyclic Amp and Lymphocytes that Adhere to Histamine Columns

Mixed lymphocytes from human peripheral blood, murine spleens, lymph nodes or thymus glands have pharmacologically specific receptors for histamine, beta mimetic catecholamines and prostaglandins. When these cells are exposed to the panoply of drugs mentioned above, their intracellular cyclic AMP concentrations increase. The biologic consequences of such an increase were at first elusive. Now we know that the immune potential of sme murine spleen cells may be modulated and the release of lysosomal enzymes and histamine from human leukocytes may be inhibited.

This paper concentrates on the effects that manipulation of cells with amine receptors has on their immune function. Recent studies have revealed that a subpopulation of splenic suppressor T cells responds to increases in its cyclic AMP content by reversing its suppressive effects on the humoral antibody response. When these T cells are removed from the murine cell population by their differential adherence to insolubilized conjugates of histamine with albumin, the remainder of the cells are more responsive to sheep cell antigen, as tested by transferring the spleen cells together with the antigen into lethally irradiated recipient animals. The suppressor T cells that adhere to the insolubilized conjugates of histamine-albumin (called histamine-rabbit serum albumin-Sepharose, or HRS) are Ia positive, they appear to have receptors for histamine, beta adrenergic amines and prostaglandins of the E series, and when stimulated by these agents their in vivo and in vitro suppressor actions are reversed. The reversal seems quantitatively dependent on cyclic AMP accumulation.

Receptors for the amines and prostaglandins are found on the T cell precursors of cell mediated in unity. They develop on some T effector cells in selected models of allogeneic target cell lysis. The receptors also appear to develop on selected B cells once these cells become conitted to antibody production.

The distribution of receptors on all leukocytes has not been adequately studied nor has their full potential in the imune response been studied in detail.     

Effects of azelastine on allergen- and exercise-induced asthma

The effects of the new anti-allergic drug, azelastine, on allergen- and exercise-induced asthma were studied. In six allergen inhalation tests for five asymptomatic asthmatic patients, the maximum percentage fall in FEV1.0 immediately after inhalation of allergen extract was 37.2 +/- 6.4 per cent (mean +/- SEM). As compared with a placebo, the maximum percentage fall in FEV1.0 with azelastine after inhalation of allergen extract in the same manner as with the placebo was 17.3 +/- 6.9 per cent. The difference was statistically significant (p less than 0.05). The percentage fall in FEV1.0 with placebo and azelastine in late asthmatic response (n = 4) was 36.0 +/- 5.3 per cent and 10.0 +/- 5.2 per cent, respectively. The difference was also statistically significant (p less than 0.01). An exercise test was carried out on seven asymptomatic asthmatic patients using an inclined treadmill. The maximum percentage fall in FEV1.0 without drugs, with diphenhydramine and azelastine was 38.9 +/- 5.0 per cent, 20.1 +/- 3.8 per cent and 11.3 +/- 3.1 per cent, respectively. Significant differences were found among each group (p less than 0.05). Azelastine was regarded as having sufficient potency to inhibit exercise-induced asthma; however, placebo effects cannot be ruled out with regard to the effects of diphenhydramine. These results suggests that chemical mediator release is involved not only in allergen-induced asthma but also in exercise-induced asthma, suggesting the clinical utility of azelastine.     

Inhibitory Effect of Calcium Antagonists on Histamine Release from Human Leukocytes

A study was made of the influence of calcium antagonists on human basophil histamine release induced in vitro by specific antigen, anti-IgE or the calcium ionophore A23187. Both verapamil, nifedipine, and nimodipine were found to inhibit the release, and a similar effect was also observed after peroral administration of verapamil and nifedipine. The inhibitory effect of the drugs on histamine release seems to depend on interaction with calcium at different sites. The anti-allergic effect might explain the improvement found with calcium antagonists in exercise-induced asthma.     

Effect of azelastine on the seasonal increase in non-specific bronchial responsiveness to methacholine in pollen allergic patients. A randomized, double-blind placebo-controlled, crossover study

Azelastine, a phthalazinone derivative, is a new potent, long acting, orally active anti-allergic compound with particularly strong H1-histamine receptor antagonistic effects which has been proven to possess in vitro and in vivo a number of anti-inflammatory properties. The aim of the present study was to investigate whether azelastine would be able to prevent and/or reverse the seasonal increase in non-specific bronchial responsiveness to methacholine in pollen allergic patients. Twelve atopic patients (5 males, mean age 31 years), skin positive exclusively to grass and/or Parietaria pollen extract, with rhinitis and mild asthma occurring in the spring for at least two years previously, were studied. After a 2 week run-in period, oral azelastine, 4 mg twice daily, or placebo, was given for 2 weeks from the start of the pollen season, according to a randomized, double-blind design. After 2 weeks, the treatments were crossed over. During both the run-in and study periods, patients recorded rhinitis and asthma symptoms, additional antihistamine and bronchodilator drugs taken and peak expiratory flow measurements. A methacholine inhalation test was carried out on four occasions in each patient: before the run-in period, before the start of the treatment, and at the end of the two 2 week treatment periods. Azelastine significantly reduced rhinitis symptoms and the need for antihistamine drugs, whereas asthmatic symptoms, use of bronchodilator drugs, peak flow recordings and bronchial responsiveness to methacholine were unaffected by the treatment. Compliance level and adverse side-effects were not significantly different between active treatment and placebo. In the final subjective evaluation of the two treatments, eight out of 12 patients preferred azelastine.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characterization of augmentation of allergic and non-allergic histamine release by non-steroidal anti-inflammatory/analgesic agents

Augmentation of allergic histamine release from human leukocytes previously was shown to be produced by numerous acidic anti-inflammatory/analgesic agents. In the present study, cicloprofen or diclofenac, representative of the arylalkanoic and anthranilic acids, respectively, augmented the antigen-dependent first stage and the calcium-dependent second stage of allergic histamine release. Both agents enhanced the rate and total amount of histamine release in the whole reaction. Further, it was demonstrated that augmentation could occur in a specific, non-cytolytic manner. In extended studies, cicloprofen and diclofenac augmented ionophore (A23187)- and concanavalin A-induced histamine release from human leukocytes and ionophore-induced release from rat mast cells. Concanavalin A- and ovalbumin-induced release from rat mast cells were inhibited by cicloprofen and diclofenac. These findings define systems useful for the study of the mechanisms of action of the acidic anti-inflammatory agents.An abstract of these studies was presented at the meeting of the Federation of American Societies for Experimental Biology, USA, April 1–10, 1979. Abstract #1959,Federation Proceedings 38, 598 (1979).     

Effect of NZ-107, a newly synthesized pyridazinone derivative, on antigen-induced contraction of human bronchial strips and histamine release from human lung fragments or leukocytes.

The effects of a newly synthesized pyridazinone derivative, NZ-107, 4-bromo-5-(3-ethoxy-4-methoxybenzylamino)-3(2H)-pyridazinone, and two well-known antiasthmatic drugs, amlexanox (orally active disodium cromoglycate-like drug) and disodium cromoglycate (DSCG) on antigen-, histamine- and leukotriene C4 (LTC4)-induced constriction of isolated human tracheal muscle, and histamine release from human lung tissues and leukocytes were investigated in vitro. In some experiments, salbutamol was used as a reference drug. NZ-107 inhibited antigen-, histamine- and LTC4-induced contraction of tracheal muscle. Amlexanox and DSCG did not affect the contractile response of tracheal muscle caused by each stimulant. Salbutamol inhibited antigen-induced contraction of tracheal muscle. NZ-107, amlexanox, DSCG and salbutamol clearly inhibited the antigen-induced release of histamine and LTC4 from human lung tissue. The antigen-induced histamine release from atopic human leukocytes was inhibited by NZ-107 and amlexanox, but not by DSCG. Pretreatment with IL-3 did not alter antigen-induced contraction of tracheal muscle and histamine release from lung tissue, but antigen- or calcium ionophore A 23187-induced histamine release from leukocytes was clearly enhanced. Amlexanox inhibited the IL-3-induced enhancement of histamine release from leukocytes in the case of both stimuli, but NZ-107 and DSCG had no effect. These data suggest that NZ-107 has potent anti-allergic actions based on the inhibition of antigen-induced contraction of human tracheal muscle and mediator release from human lung tissue and leukocytes.