Histamine-releasing Activity Research Articles

Flow cytometric analysis of basophil numbers in chronic urticaria: basopenia is related to serum histamine releasing activity.

Peripheral blood basophils are reduced in some chronic urticaria patients when counted with granule stains. Approximately 30% of patients with severe chronic urticaria have functional autoantibodies which release histamine from healthy donor basophils in vitro but the relationship between basophil numbers in vivo and serum histamine releasing activity has not been studied. To determine the relationship between basophil numbers and serum basophil histamine releasing activity and to assess whether basophils are present, but undetectable, in peripheral blood with granule stains by using a new flow cytometric method based on surface immunophenotype. Basophils were counted manually by a chamber method using a granule stain and by flow cytometry using dual staining with anti-IgE and anti-Fc epsilonRI in 25 chronic idiopathic urticaria patients and 25 healthy controls. Serum histamine releasing activity was assessed on healthy donor basophils in vitro and by the weal response to autologous serum skin testing in vivo (patients only). Basophils were significantly reduced in chronic urticaria by manual counting and flow cytometry. A subgroup of seven patients with in vitro histamine releasing activity showed a marked reduction or absence of basophils by both methods. There were no obvious distinguishing clinical characteristics between these patients and the others; six of them showed positive autologous serum skin-test responses. On comparing the two methods, the manual basophil counts were generally lower than flow cytometric counts. Agreement over the full range of values was not strong and therefore counts obtained by the two methods are not directly interchangeable. Basopenia in chronic idiopathic urticaria is associated with serum basophil histamine releasing activity in a subgroup of patients. The lack of granule and surface immunophenotype staining suggests a reduction in numbers rather than an inability to detect circulating degranulated cells by conventional counting methods.

Flow cytometric analysis of basophil numbers in chronic urticaria: basopenia is related to serum histamine releasing activity

Flow cytometric analysis of basophil numbers in chronic urticaria: basopenia is related to serum histamine releasing activity

Betidamino acid scan of the GnRH antagonist acyline.

Strong clinical evidence suggests that GnRH antagonists will replace GnRH agonists in a number of indications because of their ability to inhibit gonadotropin secretion as long as an adequate concentration of the analogue is present in the circulation whereas superagonists will take approximately 2 weeks to desensitize the gonadotrophs. Until recently, antagonists were either too weak and/or would release histamine. Azaline B {[Ac-D2Nal1,D4Cpa2,D3Pal3, 4Aph5(atz),D4Aph6(atz),ILys8,DAla10] GnRH} and long-acting members of the azaline family {Ac-D2Nal-D4Cpa-D3Pal-Ser-4Aph(X)-D4Aph(Y) -Leu-ILys-Pro-DAla-NH2}, however, appear to be promising drug candidates. Because these antagonists tend to form gels (due to the formation of beta-sheet structures) and, as a result, are not readily amenable to formulation for long-term delivery, we have investigated ways of increasing hydrophilicity while retaining high potency and lack of histamine releasing activity. Betidamino acids (a contraction of "beta" position and "amide") are N'-monoacylated (optionally, N'-monoacylated and N-mono- or N,N'-dialkylated) aminoglycine derivatives in which each N'-acyl/alkyl group may mimic naturally occurring amino acid side chains or introduce novel functionalities. We have used unresolved N alpha-Boc,N'alpha-Fmoc-aminoglycine, and N alpha-Boc,N'alpha-(CH3)Fmoc-aminoglycine as templates for the introduction of betidamino acids in acyline (Ac-D2Nal-D4Cpa-D3Pal-Ser-4Aph(Ac)-D4Aph(A c)-Leu-Ilys-Pro-DAla-NH2), a long acting member of the azaline B family, to test biocompatibility of these betide derivatives. Diastereomeric peptides could be separated using RP-HPLC in most cases. Biological results obtained in vitro (binding affinity to rat pituitary gland membranes) and in vivo (rat antiovulatory assay, AOA) indicate in most cases small differences in relative potencies (< 5-fold) between the D- and L-nonalkylated betidamino acid-containing acylines. Importantly, most betide diastereomers have high affinity for the GnRH receptor and were equipotent with acyline in the AOA. Greater differences in affinity and potency between diastereomers were observed after introduction of a methyl group on the side chain nitrogen ("beta" position) of the same analogues, with one of the diastereomer having an affinity and a potency in the AOA equivalent to that of acyline. These results suggest that chirality at the alpha-carbon coupled to side chain orientation is important for receptor recognition. The duration of action of some of the most potent analogues was also determined in the castrated male rat in order to measure the extent (efficacy and duration of action) of inhibition of luteinizing hormone release. Data suggest that introduction of a betidamino acid results in reduction of duration of action. Also, introduction of betidamino acids results in peptides with increased hydrophilicity (as determined by elution times on C18 silicas at pH 7.3) compared to that of the parent compound. N'-Methyl substitution results in parallel increase in retention times on C18 silicas as expected.

Priming and inducing effects of interleukin‐3 on histamine release from cord‐blood basophils

The effect of interleukin-3 (IL-3) on histamine release from cord and adult blood basophils were evaluated. Leukocyte suspensions, obtained from adult patients with respiratory allergy (n = 15), normal adult subjects (n = 15), and neonates with (n = 15) and without (n = 19) atopic disposition, were stimulated with anti-IgE, fMLP, and IL-3. IgE-mediated histamine release was significantly higher in adult patients, either allergic or normal, than in neonates with or without atopic disposition. A trend toward higher fMLP-induced histamine release was found in allergic adult subjects. IL-3 had a weak direct histamine-releasing activity in allergic adult subjects and in neonates, but not in normal adult donors. A significant enhancing effect of IL-3 on histamine release induced by anti-IgE was observed in neonates with and without atopic disposition and in normal adult subjects, but not in atopic adult patients. IL-3 exerted a priming effect also when basophils were stimulated with fMLP, without any significant difference between neonates and adult subjects. Passive sensitization with IgE-rich serum resulted in a significant increase in anti-IgE-induced, but not in IL-3-induced, histamine release from cord-blood basophils. In conclusion, IL-3 primes cord-blood as well as adult blood basophils for a consecutive anti-IgE- or fMLP-induced histamine release and its activity is not limited by the low density of membrane IgE in cord-blood basophils.

The Pathogenesis of Chronic Idiopathic Urticaria

Chronic idiopathic urticaria (CIU) can be extremely disabling and difficult to treat, with little response to antihistamine therapy. The pathogenic mechanisms of the disease are not well understood, but the primary effector cell is the mast cell. Release of mast cell mediators can cause inflammation and accumulation and activation of other cells, including eosinophils, neutrophils, and possibly basophils. Recent work has demonstrated that about one third of patients with CIU have circulating functional histamine-releasing autoantibodies that bind to the high-affinity IgE receptor (Fc epsilon RI) or, less commonly, to IgE; mast cell-specific histamine-releasing activity that has not yet been fully characterized; no identifiable circulating histamine-releasing activity. The mainstay of treatment of CIU consists of antithistamines, but immunotherapy using plasmapheresis, intravenous immunoglobulin, and cyclosporin may be valuable in severely affected patients with treatment-resistant disease. The response to immunomodulation and the recent finding of an association with HLA DR4 lend further support for an autoimmune basis to CIU in some patients.

好中球の殺菌性ペプチドＣＡＰ１１とデフェンシンの生物活性と遺伝子発現の比較

Defensin has been known as a major antimicrobial component of neutrophil granules. Recently, we have purified a novel cationic antibacterial polypeptide of 11 kDa (CAP11) from guinea pig neutrophilis. In this study, we have compared the biological activity and gene expression between CAP11 and defensin. When stimulated, CAP11 was extracellularly released from neutrophils, accompanied by the release of a specific granule component (lysozyme), whereas defensin was released, accompanied by the release of an azurophil granule component (β-glucoronidase) . Defensin modulated neutrophil functions such as adhesion, phagocytosis and superoxide anion generation. However, CAP11 did not affected the neutrophil functions. Both CAP11 and defensin possessed histamine-releasing activity for mast cells, but CAP11 was 10-fold less potent than defensins. CAP11 exhibited 8-fold more antibacterial activity against Escherichia coli than defensin, and the activity was retained even in the presence of physiological concentration of NaCl, although the activity of defensin was completely lost in the presence of NaCl. Sequence analysis of CAP11 cDNA showed that pre-prosequence of CAP11 was similar to the sequences of cathelicidin family polypeptides. Furthemore, in situ hybridization study revealed that CAP11 mRNA was highly expressed in metamyelocytes among bone marrow cells. In contrast, defensin mRNA was expressed in promyelocytes and myelocytes. Together these observations indicate that CAP11, a member of cathelicidin family, which is synthesized during the late stage of neutrophil maturation and stored possibly in the specific granules, is released from stimulated neutrophils and functions as an antibacterial molecule in the extracellular milieu, whereas defensin released from the azurophil granules likely participate in the modulation of neutrophil functions and mast cell histamine release.

Histamine-releasing activity in supernatants of mononuclear cells: Contribution of monocyte chemotactic protein-1 activity compared with IgE-dependent activity

Background: Supernatants of cultured human mononuclear cells contain factors that induce histamine release from basophils. Some of the histamine-releasing factors present are IgE-independent, but an IgE-dependent form has also been described. The IgE that does respond to the IgE-dependent histamine-releasing factor was defined as IgE +. Objective: This study was conducted to analyze the contribution of chemokines, such as monocyte chemotactic protein-1 (IgE-independent), to improve the detection of IgE-dependent histamine-releasing factor. Methods: Supernatants were prepared from mononuclear cells of three subjects. Monocyte chemotactic protein-1 content and histamine-releasing activity (HRA) were measured. Depletion of chemokine activity was carried out with heparin-Sepharose (Pharmacia, Uppsala, Sweden). Results: Replacing IgE - on basophils with IgE + serum decreased the correlation between monocyte chemotactic protein-1 and histamine release ( p = 0.80, n = 280 vs p = 0.12, n = 18; p for difference between p values: <0.05). After depletion of chemokines in three supernatants derived from mononuclear cells, IgE-dependent HRA was still present. Conclusion: We conclude that in supernatants derived from mononuclear cells, the IgE-independent HRA masks the IgE-dependent HRA. The latter can be more clearly detected after depletion of chemokine activity with heparin-Sepharose. (J A LLERGY C LIN I MMUNOL 1996;98:962-8.)

Dose relationship between GnRH antagonists and pituitary suppression.

While the clinical significance of gonadotrophin-releasing hormone (GnRH) agonists is well recognized, the potential use of GnRH antagonists in humans awaits the availability of potent analogues with no untoward side-effects. We have designed, synthesized and tested several hundred linear and cyclic analogues (agonists and antagonists) of GnRH in different rat models; some have high histamine releasing activity and others have poor solubility in aqueous buffers with a pH > 6.0. Furthermore, we have identified analogues exhibiting short (< 12 h), intermediate (12-72 h) and long (> 72 h) duration of action in the rat (50 micrograms s.c. dose/rat). We have concluded that the basis for such resistance to degradation and elimination must be specific. In order to gain further information on the optimal nature and sterical requirements of side-chains, preliminary experiments were carried out using betidamino acids. Finally, mono- and dicyclic analogues of GnRH with potencies comparable with that of the most potent linear analogues were also obtained. Our approach to the development of such analogues included the use of nuclear magnetic resonance and computational techniques as well as that of state-of-the-art synthetic approaches. We intend to use the information derived from these structure/activity relationship studies to design conformationally-similar peptido-mimetics.

HISTAMINE RELEASE AND CHANDONIUM IODIDE

Histamine releasing activity of chandonium iodide and d-tubocurarine was studied in guinea pig ileum (in vitro), guinea pig peritoneum (in vivo) and in human volunteers (in vivo) by intradermal testing at dilutions of 1:1,000 and 1:10,000 of the clinical dosage of drugs. d-tubocurarine revealed significant histamine releasing activity in in vivo animal experiments and high incidence of positive intradermal reaction, 53.5 per cent and 13.5 per cent, in human volunteers. Chandonium iodide neither showed histamine releasing activity in animals nor in man. In clinical terms, chandonium iodide appears to be a safe neuromuscular blocking agent.

Characteristics of histamine-releasing activity in the sera of patients with chronic idiopathic urticaria

Background: The serum histamine-releasing activity (HRA) found in a sizable percentage of patients with chronic idiopathic urticaria (CIU) has been partially characterized. However, the variable effect of individual HRA + sera in basophils of different donors and the relationship of HRA to the clinical course require further investigation. Objective: The study was performed to characterize the HRA found in sera of some members of a sizable group of carefully evaluated patients with CIU. Methods: Sera of 70 patients with CIU, evaluated with a standard protocol, were screened for increased HRA. HRA + sera were fractionated, heated, and tested on unaltered and altered basophils obtained from a panel of normal donors. HRA levels were compared with concomitant clinical manifestations. Results: HRA + sera were found in 30% of our patients with CIU. HRA was predominantly in the IgG fraction, sensitive to 56° C heating for 4 hours, and generally reacted more with IgE-stripped basophils. Considerable variation in the degree of response to HRA + sera in the basophils of different normal subjects did not correlate with the degree of response of these cells to heterologous anti-IgE antiserum. Serum HRA levels were generally much lower when symptoms decreased in these patients with CIU. Conclusion: Serum HRA from patients with CIU appears to bind most commonly to the IgE receptor and may be a marker of clinical disease activity. HRA appears in an IgG-containing fraction of the serum and may contain IgE in some cases. (J ALLERGY C LIN I MMUNOL 1996;98:89-98.)

Lectins do not distinguish between heterogenous IgE molecules as defined by differential activity of an IgE-dependent histamine releasing factor

It has been suggested that the differential histamine-releasing activity of an IgE-dependent histamine-releasing factor (HRF), which has recently been cloned, is related to carbohydrate differences in the IgE molecule. Lectins are able to recognize specific glycoforms and might therefore be useful in characterizing the proposed heterogeneity of IgE molecules. As one test of this hypothesis, we examined the histamine release potency of several well-characterized lectins on basophils passively sensitized with serum containing IgE molecules that support HRF-induced histamine release (IgE +) or serum that does not support release by this stimulus (IgE −). Histamine release was induced by challenging basophils with different concentrations of concanavalin A, Lens culinaris (LcH), and Pisum sativum (PSA). Dose-response curves revealed that LcH caused 30% histamine release at 2 μg/ml with IgE + sensitized cells, whereas the same release with IgE − cells required sixfold higher concentrations. Similar values for PSA showed a sevenfold difference. With concanavalin A, the selectivity was reversed in that it was fourfold more active on IgE −-sensitized cells. Another pair of sera (IgE + vs IgE −) revealed the same result for concanavalin A, but no difference occurred in LcH and PSA induced release between the IgE +- and IgE −-sensitized cells. These contrasting findings with different pairs of IgE +- and IgE −-containing sera indicated that the lectins LcH and PSA are not able to discriminate between IgE +- and IgE −-sensitized cells as does HRF and therefore cannot be used to further define the proposed heterogeneity of IgE. This conclusion was supported by experiments in which basophil preparations from donors possessing natural sensitivity or insensitivity to HRF (having IgE + or IgE − on their surface) were examined for their response to these lectins. No difference was found in the sensitivity of the cells to challenge with LcH or PSA, and the response to concanavalin A was the opposite of that found when passively sensitized cells were used (30% histamine release at 0.9 vs 3.5 μg/ml for IgE + vs IgE − donors, respectively). We conclude that oligosaccharide-specific lectins do not differentiate between HRF-reactive and HRF-nonreactive IgE molecules on basophils. (J A LLERGY C LIN I MMUNOL 1996;98:181-8.)

971 Modulation of the histamine releasing activity (HRA) present in the serum of patients with chronic idiopathic urticaria (CIU)

971 Modulation of the histamine releasing activity (HRA) present in the serum of patients with chronic idiopathic urticaria (CIU)

Structure activity studies of mast cell activation and hypotension induced by neuropeptide Y (NPY), centrally truncated and C-terminal NPY analogues.

1. Neuropeptide-induced histamine release is thought to occur via receptor-independent mechanisms, with net charge and lipophilicity being important factors. 2. In this study, the histamine releasing ability of neuropeptide Y (NPY), two C-terminal segments of NPY and 13 centrally truncated NPY analogues was examined. These results were compared with the ability of the peptides to bind to the Y2 receptor in the rabbit kidney membrane model and with their hypotensive actions in the anaesthetized-rat model. 3. All analogues tested, with the exception of [Glu4,25,33,35]-NPY(1-4)-Ahx-(25-36) and [Asp4,25,33,35]NPY(1-4)-Ahx-(25-36) which were devoid of histamine releasing activity, evoked a dose-dependent histamine release but there were marked differences between the peptides. The native peptide was the least active. 4. Histamine release was not linked to the ability of the peptides to displace NPY from Y2 receptors. There was a statistical correlation between the hypotensive effects expressed as ED10 values (mumol kg-1, which induced a blood pressure decrease of 10 mmHg) and the EC25 for histamine release (r = 0.62, P = 0.04), although histamine release may not be the sole determinant of the alterations in blood pressure. 5. There was a strong negative correlation between EC25 for histamine release and net positive charge (r = -0.93, P = 5.7 x 10(-7), i.e. increasing the net positive charge caused greater histamine release. However, there was a 12 fold difference in activity amongst the most positively charged analogues (+5). Helicity did not correlate with histamine releasing ability. 6. In the development of NPY-related drugs the avoidance of compounds with net positive charge is recommended.

Pharmacologic study of basophil histamine release induced by monocyte chemotactic protein-1 with kinase inhibitors.

Monocyte chemotactic protein-1 (MCP-1)/monocyte chemotactic activating factor has a potent histamine-releasing activity for basophils and is a major component of IgE-independent histamine-releasing factors (HRF). In this study, we examined the effect of a panel of kinase inhibitors on MCP-1-induced histamine release from human basophils to characterize the signaling pathway used by this chemokine. Genistein (3 micrograms/ml), an inhibitor of tyrosine kinase, inhibited MCP-1-induced histamine release by 44%. Wortmannin is a specific inhibitor of phosphatidylinositol 3 kinase (PI-3 kinase). It blocked MCP-1-induced histamine release with an IC50 of 3.3 x 10(-8) M indicating a role of PI-3 kinase in this reaction. KT5926, an inhibitor of myosin light chain kinase, also inhibited histamine release in response to MCP-1 with an IC50 of 10(-6) M. Staurosporine, a potent inhibitor of protein kinase C, although being not specific, augmented MCP-1-induced histamine release by 31.9% at 10(-6) M. These results indicate the possible involvement of a series of kinases, including PI-3 kinase, in the signal transduction pathway used by MCP-1.

Influence of α-helicity, amphipathicity and D-amino acid incorporation on the peptide-induced mast cell activation

Mast cell activation by polycationic substances is believed to result from a direct activation of G protein α subunits and it was suggested that the adaption of amphipathic, α-helical conformations wouuld allow the peptide to reach the cytosolic compartment to interact with G proteins (Mousli et al., 1994, Immunopharmacology 27, 1, for review). We investigated the histamine-releasing activity of model peptides as well as analogues of magainin 2 amide and neuropeptide Y with different amphipathicities and α-helix content on rat peritoneal mast cells. Amphipathic helicity is not a prerequisite for mast cell activation. Moreover, non-helical magainin peptides with high histamine-releasing activity were less active in the liberation of carboxyfluorisceine from negatively charged liposomes, indicating that peptide-induced mast cell activation and peptide-induced membrane perturbation do not correlate. In contrast to the negligible influence of the secondary structure, amino acid configuration may exert a striking influence on peptide-induced mast cell activation. Thus histamine-release by substance P was markedly impaired when the L-amino acids in the positively charged N-terminal region were replaced by D-amino acids, with [D-Arg 1]substance P being the most inactive substance P diastereoisomer.

IgE binding to a human profilin–containing fraction caused by contamination with yeast-derived material

J A LLERGY C LIN I MMUNOL 1995;96:696-7.

Involvement of cysteine residues in the biological activity of the active fragments of guinea pig neutrophil cationic peptides.

Guinea pig neutrophil cationic peptides (GNCPs) are single-chain polypeptides with 31 amino acid residues containing six cysteine residues, which exhibit both antibacterial and histamine-releasing activities in vitro. In this study, the role of the sulfhydryl groups in defining the antibacterial and histamine-releasing activities of the active fragments of GNCP-1 (Arg-1 to Tyr-14 [Arg-1-Tyr-14] and Arg-15-Tyr-27 peptides) was examined by using peptides containing alkylated or nonalkylated sulfhydryl groups. Alkylation slightly increased the histamine-releasing activity of the Arg-15-Tyr-27 (RRLGTCIFQNRVY) peptide but abrogated the antibacterial activity. Alkylation of the Arg-1-Tyr-14 (RRCICTTRTCRFPY) peptide similarly reduced the antibacterial activity of this fragment but had minimal effect on the histamine-releasing activity. These findings suggest that cysteine residues with free sulfhydryl groups play an important role in the expression of the antibacterial activity of the active fragments of GNCP-1.

The Release and Subsequent Synthesis of Histamine in a Transfected Subclone of Rat Basophilic Leukemia Cells That Expresses Human Muscarinic ml Receptors

Effects of carbachol and antigen (dinitrophenylated bovine serum albumin) on histamine release and histidine decarboxylase (HDC, the enzyme synthesizing histamine) activity were studied in 2H3-m1 cells, a subclone of rat basophilic leukemia cells that expresses human muscarinic ml receptors through transfection with the gene. Carbachol stimulated the release of histamine and the activity of HDC with 30–50% the intensity of the maximal effect of the antigen. Pirenzepine, an ml antagonist, inhibited these carbachol effects in a dose-dependent manner. The effect of the combination of carbachol and antigen on histamine release showed no additivity. These results indicate that these effects of carbachol are exerted via ml receptors, and they suggest that the actions of carbachol and antigen on histamine release share a common pathway(s), and the release and synthesis of histamine have a positive relationship like in a feedback system.

P1-254 - Effects of repeated administration with methamphetamine on the neuronal histamine release and histidine decarboxylase activity in the rat striatum

P1-254 - Effects of repeated administration with methamphetamine on the neuronal histamine release and histidine decarboxylase activity in the rat striatum

Circular dichroism (CD) studies on biological activity of mast cell degranulating (MCD) peptide analogs.

Analogs of MCD peptide were synthesized by solid-phase methods. Positive charges were deleted at the N-and/or C-terminus, including the helical portion of the molecule. Four peptides were prepared by removing residues 16-18 (Arg-Lys-Ile), 1-2 (Lys), 1-2 and 16-18 and by acetylation of the amino end (Ile). Analogs were tested on mast cells for histamine-releasing activity. Although the helicity of these derivatives, determined by circular dichroism (CD), was not significantly different from the native MCD peptide, two analogs with C-terminal deletions showed a 5- to 10-fold decrease in activity. These findings suggest that the C-terminus is more important than the N-terminus in determining bioactivity of MCD peptide.