Raffaele Cirillo

Human basophil/mast cell releasability. IX. Heterogeneity of the effects of opioids on mediator release.

Opioids differ in their capacity to cause release of histamine. The effects of increasing concentrations of three opioids (morphine, buprenorphine, and fentanyl) were studied on the release of preformed (histamine and tryptase) and de novo synthesized (prostaglandin D2 [PGD2] and peptide-leukotriene C4 [LTC4]) chemical mediators from human peripheral blood basophils and mast cells isolated from skin tissues or lung parenchyma. Basophils released < 5% of their histamine content and did not synthesize significant amounts of LTC4 when incubated with any of the opioids. Mast cells showed markedly different responses to the three opioids. Morphine (10(-5)-3 x 10(-4) M), in a concentration-dependent manner, induced histamine and tryptase release from skin but not from lung mast cells, up to a maximum of 18.2 +/- 1.9% and 13.0 +/- 4.1 micrograms/10(7) cells, respectively. Morphine did not induce de novo synthesis of PGD2 from skin mast cells. Buprenorphine (10(-6)-10(-4) M), in a concentration-dependent manner, caused histamine and tryptase release from lung but not from skin mast cells, to a maximum of 47.6 +/- 7.2% and 35.1 +/- 13.6 micrograms/10(7) cells, respectively. Buprenorphine also induced de novo synthesis of PGD2 and LTC4 from lung mast cells. Fentanyl (10(-5)-10(-3) M) did not induce histamine and tryptase release or the de novo synthesis of PGD2 or LTC4 from any mast cells. Histamine release caused by buprenorphine from lung mast cells was slow (t1/2 = 11.2 +/- 3.6 min) compared with that induced by morphine from skin mast cells (t1/2 < 1 min, P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Heterogeneity of Human Mast Cells and Basophils in Response to Muscle Relaxants

The authors studied the effects of increasing concentrations 10(-5)-10(-3) M) of four muscle relaxants (succinylcholine, d-tubocurarine, vecuronium, and atracurium) on histamine release from peripheral blood basophils and mast cells isolated from human lung parenchyma, skin tissues, and heart fragments. Basophil granulocytes released less than 5% of their histamine content when incubated with any one of the muscle relaxants tested. In contrast, mast cells showed a significant heterogeneity in response to different muscle relaxants. Succinylcholine did not induce histamine release from any type of mast cell, and only high concentrations of d-tubocurarine (10(-3) M) caused histamine release from skin and lung mast cells. Vecuronium concentration-dependently induced histamine release from skin and lung--but not from heart mast cells--to a maximum of 7.2 +/- 2.1% and 4.9 +/- 1.4%, respectively. Atracurium concentration-dependently caused significant histamine release from skin and lung mast cells to a maximum of 46.2 +/- 15.1% and 30.6 +/- 6.0%, respectively. Atracurium (5 x 10(-5) - 2 x 10(-4) M) also induced histamine release from heart mast cells. The histamine release process from both lung and skin mast cells caused by atracurium and vecuronium was extremely rapid (t1/2 = less than 1 min). The releasing activity of atracurium and vecuronium on lung and skin mast cells was not reduced, and not abolished, by lowering the temperature of the incubation buffer to 22 degrees C and 4 degrees C. Extracellular calcium did not affect the capacity of atracurium and vecuronium to induce histamine release from lung and skin mast cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of Histamine and Prostaglandin D2 Release from Human Lung Mast Cells by Ciclosporin A

Cyclosporin A (CsA) is now widely used in the prevention/treatment of graft rejection and in the treatment of some human inflammatory diseases. We studied the effect of CsA on the release of chemical mediators from human lung mast cells in vitro. CsA (0.03-3 micrograms/ml) inhibited the release of histamine and prostaglandin D2 induced by anti-IgE from lung mast cells. CsA-induced inhibition of mediator release was not abolished by washing the cells before stimulation and it was not affected by the degree of purity of mast cell preparations. Our results indicate that CsA, in pharmacological concentrations, is a rapid and irreversible inhibitor of the release of preformed and de novo synthesized mediators from human lung mast cells. These findings might explain, at least in part, some of the therapeutic actions of CsA in vivo.

Cyclosporin H is a potent and selective competitive antagonist of human basophil activation by N-formyl-methionyl-leucyl-phenylalanine

BACKGROUND Cyclosporin A (CsA) binds with high affinity to cyclophilin, a critical step in the molecular mechanism of action of cyclosporins, where cyclosporin H (CsH) has extremely low affinity for cyclophilin. CsH differs from CsA by the substitution of the L-methyl valine at position 11 with it D-isomer. METHODS We compared the effects of CsA and CsH on the release of performed (histamine) and de novo synthesized inflammatory mediators (peptide leukotriene C4) from peripheral blood basophils activated by N-formyl-methionyl-leucyl-phenylalanine (FMLP). RESULTS CsH (8 to 800 nmol/L) concentration-dependently inhibited histamine and leukotriene C4 release from purified and unpurified basophils activated by FMLP, whereas CsA (8 to 800 nmol/L) had little inhibitory effect on histamine release from basophils challenged with FMLP. Inhibition of histamine release from basophils challenged with FMLP was extremely rapid and was abolished by washing the cells (three times) before challenge. CsH (8 to 800 nmol/L) had no effect on the release of histamine caused by C5a, platelet activating factor, monocyte chemotactic activating factor, RANTES, IL-8, bryostatin 1, and phorbol myristate. Preincubation of basophils with granulocyte-macrophage colony-stimulating factor (30 and 100 pmol/L), but not IL-1 beta (30 and 100 ng/ml), concentration-dependently reversed the inhibitory effect of CsH on FMLP-induced histamine release. CsH competitively inhibited the effect of FMLP on histamine release from basophils. The dissociation constant (Kd) for the CsH-FMLP receptor complex was approximately 9 x 10(-8) mol/L, more than 10-fold lower than that (approximately equal to 1.3 x 10(-6) mol/L) of N-t-BOC-methionyl-L-leucyl-phenylalanine (BocMLP), a known formyl peptide receptor antagonist. CsH inhibited tritiated FMLP binding to human polymorphonuclear leukocytes with a concentration required to inhibit binding by 50% of approximately 5.4 x 10(-7) mol/L, whereas BocMLP was less potent with a concentration required to inhibit binding by 50% of approximately 9.1 x 10(-5) mol/L. Scatchard analysis revealed that the decreased tritiated FMLP binding caused by CsH was due to a decrease in the Bmax (0.22 +/- 0.04 nmol/L/5 x 10(6) cells vs 0.09 +/- 0.01 nmol/L/5 x 10(6) cells; p < 0.05), without a significant difference in the Kd (5.16 +/- 1.22 nmol/L vs 6.32 +/- 2.42 nmol/L; p = NS). CONCLUSION CsH is a potent and selective inhibitor of mediator release from basophils induced by activation of the formyl peptide receptor; it acts by interfering with agonist binding to FMLP receptors.

Pathophysiology of human basophils and mast cells in allergic disorders.

Basophil leukocytes and tissue mast cells are inflammatory cells that are found in virtually all human tissues. They appear to be involved in the pathogenesis of such allergic diseases as allergic rhinitis, bronchial asthma, anaphylaxis, atopic and contact dermatitis, chronic urticaria, and hypersensitivity pneumonitis. By releasing a variety of chemical mediators, they could also play a role in the pathophysiology of a wide range of inflammatory disorders of the joints, and of intestine, lung, coronary, and myocardial diseases. Although these two cell types are similar in several aspects, striking differences have also been observed. Moreover, human mast cells from different anatomical sites and within an individual tissue synthesize different mediators and have different release mechanisms. The recent advent of techniques that yield highly purified basophils and mast cells from diverse tissues will probably lead to major advancements in understanding the biochemical and pharmacological mechanisms that control the release process of these cells. The release of mediators from these cells is also controlled by a series of largely undefined biochemical steps that represent the basis of the concept of basophil and mast cell releasability. Alterations of basophil or mast cell releasability have already been detected in patients with allergic rhinitis, bronchial asthma, atopic dermatitis, and chronic urticaria. Taken together, these findings demonstrate that basophils, mast cells, and their chemical mediators play a pivotal role in several inflammatory disorders.

Metabolic and hemodynamic effects of peptide leukotriene C4 and D4 in man

The time course of the effects of intravenous or intracoronary administration of peptide leukotrienes on metabolic parameters and on systemic and coronary hemodynamics was evaluated in 15 patients with normal coronary arteries. Peptide leukotriene C4 (2 nmol given as a bolus intravenous injection) induced an early fall (at 2 min) in mean arterial pressure (P<0.02) associated with a rise in heart rate (P<0.001) and in plasma levels of epinephrine (P<0.05) and norepinephrine (P<0.005), but without significant changes in coronary blood flow or coronary vascular resistance. Mean arterial pressure, heart rate, norepinephrine, and epinephrine returned to baseline values 10 min after leukotriene C4 administration. In contrast, at 10 min post leukotriene C4, with coronary blood flow and myocardial oxygen consumption unchanged, an increase in coronary vascular resistance (P<0.05) and in myocardial oxygen extraction (P<0.01) was observed, which returned to baseline values at 20 min post leukotriene C4. Peptide leukotriene D4(3 nmol, given in the left coronary artery) induced an early (20 s) and transient fall in mean arterial pressure (P<0.001 ) paralleled by a rise in heart rate and plasma levels of epinephrine and norepinephrine, all of which returned to baseline at 10 min. Coronary vascular resistance increased at 10 and 15 min (P<0.02 and P<0.05, respectively) and myocardial oxygen extraction at 15 min (P<0.02). These results suggest that small doses of peptide leukotrienes induce both an early and transient fall in mean arterial pressure associated with secondary sympathoadrenergic activation, and a late increase in small coronary arteriolar resistance.

Cardiovascular and Metabolic Effects of Peptide Leukotrienes in Mana

Leukotrienes are a group of biologically active compounds derived from certain polyunsaturated fatty acids (e.g., arachidonic acid).’ Before it is transformed to leukotrienes, the precursor acid must be hydrolytically released from phospholipids. This release is catalyzed by phospholipase A: or by the sequential action of phospholipase C and diglyceride l i p a ~ e . ~ The first step in the biosynthesis of leukotrienes is catalyzed by the enzyme, 5-lipoxygenase, which peroxidizes arachidonic acid at carbon 5 to form (SS)-hydroperoxy-6-truns11,14-cis-icosatetraenoic acid (5-HPETE). This compound then is converted to the unstable epoxide intermediate, leukotriene A,., Depending upon the enzymes available, leukotriene A, may subsequently be hydrolyzed to (5S),( 12R)-dihydroxy-6,14-cis-8,1 O-truns-icosatetraenoic acid (leukotriene B,)’ or it may be converted, by means of addition of glutathione at carbon 6 , to leukotriene C, (LTC,) by leukotriene C synthase. LTC, and its metabolites-leukotrienes D4 (LTD,) and E, (LTE,)-were described originally as “slow reacting substance of anaphylaxis” (SRS-A) and are now collectively referred to as peptide leukotrienes. These compounds are very potent proinflammatory mediators and they contract smooth muscle cells from bronchus, lung parenchyma, gastrointestinal, and urogenital which means that they are implicated in the pathophysiology of several human diseases. Peptide leukotrienes are released during immunological and nonimmunological activation of several inflammatory cells such as human basophils,” lung mast cells,I2 and e o s i n ~ p h i l s . ’ ~ ~ ’ ~ They also are released in vivo during anaphylactic reactions in humans.‘’

Cyclosporin a inhibits the release of histamine and peptide leukotriene C4 from human lung mast cells

SummaryWe investigated the effect of cyclosporin A (CsA) onin vitro release of chemical mediators from mast cells purified from human lung tissues. CsA (3 x 10-2 to 1 μg/ml) dose-dependently inhibited IgE-mediated release of histamine and peptide leukotriene C4 (LTC4) from human lung mast cells. The same concentrations of CsA also inhibited the release of histamine from lung mast cells challenged with the Ca2+ ionophore A23187. Therefore, CsA in pharmacological concentrations inhibits the IgE- and non-IgE-mediated release of inflammatory mediators from mast cells purified from human lung tissues.

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.

Modulation of human lung mast cell function by the c-kit receptor ligand

The gene product of the steel locus is a growth factor for mast cells and a ligand for the c- kit proto-oncogene receptor, a member of the tyrosine kinase receptor class of oncogenes