Histamine content, synthesis and degradation in human nasal mucosa

Histamine content and enzyme activities of histamine metabolism, histidine decarboxy-lase (HDC), histamine N-methyltransferase (HMT) and histaminase (diamine oxidase, DAO) in human nasal mucosa were determined with a highly sensitive and specific fluorescent method which was combined with high performance liquid chromatography. Histamine content and HDC activity were determined in 10 specimens of nasal polyp, nine specimens of maxillary sinus and five specimens of inferior turbinate. HMT and histaminase activities were determined in 15 specimens of nasal polyp, nine specimens of maxillary sinus and five specimens of inferior turbinate obtained during surgical therapy. Histamine and activities of HDC, HMT and histaminase were detected in all specimens except the case of histaminase activity in one specimen of nasal polyp. The mean values of histamine content and activities of HDC, HMT and histaminase of human nasal mucosa were 137.3 nmol/g wet weight, 26.3 fmol/min/mg protein, 26.4 pmol/min/mg protein and 0.5 pmol/min/mg protein, respectively. Histamine content in the mucosal tissue of the maxillary sinuses was significantly higher than that of nasal polyps or inferior turbinates. There were no significant differences in HDC activities among three kinds of nasal mucosa. Activities of HMT and histaminase, including their kinetic constants (Km and Vmax values for histamine) indicated that HMT has a greater potential than histaminase for histamine degradation in the human nasal mucosa. The presence of these enzymes suggests that these activities constitute an important modulating factor in histamine mediated allergic and inflammatory reactions in human nasal mucosa.     

Histamine N-methyltransferase inhibitor potentiates histamine- and antigen-induced airway microvascular leakage in guinea pigs

Background: Histamine N-methyltransferase (HMT) modulates histamine- and antigen-induced bronchoconstriction. However, it is unclear whether vascular permeability evoked by an allergic reaction can be exaggerated by inhibition of HMT activity. Methods: We studied the effects of intravenously injected SKF 91488, a specific HMT inhibitor, on increases in plasma extravasation induced by intravenously injected histamine in unsensitized guinea pigs and by intravenously injected ovalbumin antigen in guinea pigs sensitized to ovalbumin in vivo with Evans blue dye as a marker. Results: Pretreatment with SKF 91488 shifted, in a dose-dependent fashion, the dose-response curves of the leakage of dye to histamine to lower concentrations in the trachea, main bronchi, and nasal mucosa. Likewise, pretreatment with SKF 91488 (20 mg/kg intravenously) significantly increased the leakage of dye induced by ovalbumin antigen (200 μg/kg intravenously) in three parts of the airway (p < 0.05). In contrast to SKF 91488, intravenously injected aminoguanidine, a specific inhibitor of diamine oxidase (16 mg/kg intravenously), did not alter the leakage of dye induced by histamine (from 0.001 μg/kg to 10 μg/kg intravenously) (p > 0.20). HMT activities were observed in the nasal mucosa, as well as in the trachea and main bronchi, as shown in a previous study. Conclusion: These findings suggest that HMT modulates the effects of exogenous histamine and endogenously released histamine induced by antigen challenge on plasma extravasation in the airway in guinea pigs in vivo. (J ALLERGY CLIN IMMUNOL 1995;96:910-6.)     

Nasal mucosal hypersensitivity in guinea pigs intermittently exposed to cold.

To develop an animal model for experimental nasal hypersensitivity and hyperreactivity, guinea pigs were subjected to intermittent exposure to cold temperature (intermittent cold stress, SART stress) for 5 consecutive days. In SART-stressed guinea pigs, nasal mucosal hypersensitivity to histamine evoking sneeze response and nasal hypersecretion in response to methacholine were observed. The hypersensitivity remained for further 7 days after being released from SART stress. On the other hand, such nasal mucosal hypersensitivity was not caused by a continuous cold stress alone, suggesting that intermittent exposure to cold may be of importance for the appearance of nasal mucosal hypersensitivity. In passively sensitized SART-stressed guinea pigs, the quantity of nasal secretion induced by an allergen was significantly increased compared with that of a group of normal animals. The expression of muscarinic acetylcholine receptor (m-ACh.R) became higher in SART-stressed guinea pigs. Thus, hypersensitivity and hyperreactivity in this system were found to be associated with an increase in density of m-ACh.R. SART-stressed guinea pigs will serve as an animal model for hypersensitivity in nasal mucosa, which would be useful for the study of nasal allergy.     

Influence of dietary histidine on tissue histamine concentration,histidine decarboxylase and histamine methyltransferase activity in the rat

Three-week-old male rats were fed for two weeks diets supplying inadequate, adequate, or excess amounts of histidine. After the 2-week feeding of the experimental diets, the rats were killed. Brain, gastrocnemius muscle, kidney and stomach were removed and analyzed for histamine and free-histidine as well as for the degradative enzyme, HMT, and the histamine-synthesizing enzyme HDC.The following results were obtained: As the level of dietary histidine increased, (1) tissue concentrations of free-histidine and of histamine increased in all the tissues analyzed. (2) The increase of histamine was greatest in brain and stomach (5- and 4-fold, respectively), but less in kidney and muscle (2-fold). (3) HDC activity was not detected in muscle, but doubled from the lowest to the highest histidine intake in brain and increased almost 6-fold between the lowest and the highest histidine levels in stomach. (4) Kidney HDC decreased from the lowest to the two higher levels of dietary histidine. (5) HMT activity increased nominally in brain and not significantly in kidney; none was detected in either muscle or stomach. (6) Brain and kidney, tissues with considerable HMT activity, had almost no histamine. The increases in tissue histamine concentrations observed in the tissues analyzed generally reflected the changes and magnitudes of enzyme activities for HMT and HDC. The results in the rat differ in important ways from those previously observed in chickens as follows: (1) Histamine concentrations as a function of dietary histidine decreased in the chick. (2) Both HDC and HMT activities were present in chick muscle tissue. (3) HDC activity in chick stomach decreased sharply as a function of dietary histidine.Paper of the Journal Series, New Jersey Agricultural Experiment Station; Project 14101, supported in part by US Public Health Service Grant 1R01 AM 18932 and by the Charles and Johanna Busch Memorial Fund.     

A nasal allergy model developed in the guinea pig by intranasal application of 2,4-toluene diisocyanate

An experimental model of nasal allergy has been developed in guinea pigs by intranasal application of 2,4-toluene diisocyanate (TDI). A 10% TDI solution in ethyl acetate was painted onto the nasal vestibuli of the animals once a day for 5-10 days. During the course of repeated application of TDI, the number of animals which secreted rhinorrhea containing eosinophils increased. Morphological survey of the nasal mucosa showed infiltration of eosinophils and some other changes indicative of acute inflammation. Moreover, mast cells were found not only in the subepithelial connective tissue but also in the epithelial layer. Nasal mucus obtained from the mucosa has been found to be an effective test material for studies of nasal allergy. A striking decrease of specific granules was found in some mast cells contained in the mucus. In parallel with the symptomatology, biochemical and serological studies suggested the involvement of type I allergy in the experimental system; TDI-specific histamine release from the nasal mucosa and positive passive cutaneous anaphylaxis were found 3 weeks after the application of TDI.     

Effect of age and dietary histidine on histamine metabolism of the growing chick

The effect of age and of varying the dietary histidine level, with special emphasis on histamine metabolism, was studied in male, white Leghorn chicks. The birds were fed a 19% amino acid diet with histidine supplied from 0 to 0.8% of diet. In Experiment 1, 7-day-old chicks were fed the experimental diets for 7 days. In Experiment 2, chicks were fed the experimental diets for different time intervals to equalize their body weight at time of killing. In Experiment 3, birds were killed at 5, 9, 12 and 15 days of age when their body weights reached 69, 96, 136 and 184 g, respectively. Concentrations of anserine, carnosine, free-histidine and histamine, and activities of histidine decarboxylase (HDC) and histamine methyl transferase (HMT) were assayed in whole brain, pectoralis major muscle and in proventriculus of 3 or 4 chicks per treatment group.The following results were obtained: As the level of dietary histidine increased, (1) tissue concentrations of free-histidine and of carnosine increased; (2) the activity of HMT increased; (3) the concentration of anserine remained constant; (4) the activity of HDC increased in brain and muscle, but decreased sharply in the proventriculus; (5) the concentration of histamine decreased. (6) Free-histidine concentration, HDC and HMT activities increased with an increase in age and body weight; however, histamine concentrations decreased with age and body weight. The results point to the possibility that the relatively greater increase in HMT activity compared to HDC may be responsible for the decrease in histamine concentration with increase in dietary histidine or increased age. The very high HDC activity in the proventriculus of birds fed low histidine diets may have contributed to the higher histamine concentrations in brain and muscle of birds fed low versus higher histidine-containing diets.Paper of the Journal Series, New Jersey Agricultural Experiment Station; supported in part by U.S. Public Health Service Grant IR01 AM 18932 and by the Charles and Johanna Busch Memorial Fund.     

Influence of viral infection on the development of nasal hypersensitivity

BACKGROUND: The underlying relationship between viral infections and allergic diseases of the upper respiratory tract has not been well clarified. METHODS: In order to clarify the relationship between viral infection and nasal hypersensitivity, mice were sensitized with ovalbumin (OVA) and then infected intranasally with respiratory syncytial virus (RSV), after which their nasal sensitivity to histamine or antigen was examined. RESULTS: Non-sensitized mice showed transient mild nasal hypersensitivity following nasal administration of histamine after intranasal RSV inoculation. In mice sensitized with OVA, RSV infection significantly exaggerated their nasal hypersensitivity to histamine and OVA. Treatment of these mice with a neurokinin (NK)-1/NK-2 receptor antagonist, but not with anti-IL-5 antibodies, reduced their hypersensitivity. The infiltration of nasal mucosa with eosinophils was temporarily associated with accelerated rate of RSV elimination in these animals. CONCLUSION: RSV infection induced transient nasal hypersensitivity. Several mechanisms, including impairment of nasal epithelial cells are thought to mediate this effect. In allergen-sensitized mice, RSV inoculation strongly enhanced nasal hypersensitivity.     

Elevated nasal mucosal G protein levels and histamine receptor affinity in a guinea pig model of nasal hyperresponsiveness

BACKGROUND: Nasal hyperresponsiveness is a common feature of allergic rhinitis, but the underlying mechanisms have yet to be elucidated. The effects of repeated antigen inhalation on the characteristics of histamine H(1) receptors and expression levels of heterotrimeric guanosine 5'-triphosphate-binding proteins in nasal mucosa were investigated to understand the mechanisms of the pathogenesis of nasal hyperresponsiveness in allergic rhinitis. METHODS: Male Hartley guinea pigs were sensitized by the inhalation of dinitrophenylated ovalbumin antigen (10 mg of protein/ml) and repeatedly challenged by inhaling aerosolized dinitrophenylated ovalbumin antigen for 3 weeks. Twenty-four hours after the last antigen inhalation, in vivo nasal responsiveness to histamine was measured. [(3)H]Mepyramine binding assays and immunoblotting for alpha subunits of the G(q) protein were also performed using membrane preparations of isolated nasal mucosae. RESULTS: The histamine-induced increase in intranasal pressure was significantly augmented after repeated antigen challenge, indicating that nasal hyperresponsiveness was achieved. In saturation binding studies, no significant change was observed in the density and antagonist affinity of H(1) receptors in the hyperresponsive animals. On the other hand, the affinity of histamine for high-affinity agonist binding sites in the hyperresponsive group, measured by histamine competition binding studies, was much greater than that in control animals, and these results were affected by guanosine 5'-O-(3-thiotriphosphate) in both groups. Moreover, Galpha(q) levels in nasal mucosal homogenates were significantly increased after repeated antigen challenge. CONCLUSIONS: Elevated G protein levels in nasal mucosa might induce an increased binding affinity of histamine to its receptors, resulting in an augmented nasal response to histamine, that is, nasal hyperresponsiveness, in guinea pigs.     

组胺受体拮抗剂可防治哮喘豚鼠气道重塑和酸碱平衡紊乱

目的:探讨组胺受体拮抗剂对哮喘豚鼠气道重塑和酸碱平衡紊乱的防治作用。方法:将豚鼠分为正常对照组、哮喘模型组、哮喘模型延续组、组胺组、组胺受体拮抗剂组。用高效液相色谱法检测血清组胺浓度；生化分析仪测血清Na+、Cl-浓度；血气分析仪测血pH、PaO2、PaCO2、AB、SB；图像分析系统测定气道黏膜层、平滑肌层厚度。结果:（1）哮喘模型组血清组胺浓度、气道壁黏膜层和平滑肌层厚度均明显高于正常对照组 （P<0.01）；哮喘模型延续组明显高于哮喘模型组（P<0.01）；组胺组明显高于哮喘模型延续组（P<0.01）；而组胺受体拮抗剂组低于哮喘模型延续组（P<0.05，P<0.01）；（2）哮喘模型组的PaO2低于正常对照组（P<0.01）；哮喘模型延续组的PaO2、pH、AB、SB低于、PaCO2高于哮喘模型组（P<0.01）；组胺组PaO2、pH、AB、SB低于、PaCO2高于哮喘模型延续组（P<0.01）；而组胺受体拮抗剂组PaO2、pH、AB、SB高于哮喘模型延续组（P<0.01），PaCO2则低于哮喘模型延续组（P<0.01）。示豚鼠哮喘时存在气道重塑和血清组胺浓度升高以及代谢性酸中毒与呼吸性酸中毒，外源性组胺可加重这些变化，组胺受体拮抗剂可缓解之。结论:组胺在哮喘气道重塑中起介导作用，组胺受体拮抗剂对防治哮喘气道重塑及酸碱平衡紊乱有一定作用。     

Parainfluenza virus type-3 infection attenuates the respiratory effects of antigen challenge in sensitized guinea pigs

Respiratory viral infections not only exacerbate asthma symptoms but may also be important in the pathogenesis of the disease. We therefore explored the effects of respiratory viral infection on the respiratory response of sensitized guinea pigs to antigen challenge. Lung tissue obtained from uninfected guinea pigs sensitized to ovalbumin aerosol released histamine upon incubation with the antigenin vitro. After antigen challengein vivo, sensitized animals had significantly greater numbers of eosinophils in their bronchoalveolar lavage fluid than did nonsensitized animals and exhibited airway hyperresponsiveness to methacholine aerosol. When ovalbumin sensitization was initiated 7 days after inoculation with parainfluenza virus type-3 (PI-3), antigen challenge elicited little histamine release from infected lung tissuein vitro. Likewise, subsequent to antigen challengein vivo, animals failed to exhibit airway hyperresponsiveness or an increased eosinophil population in bronchoalveolar lavage fluid. Similar effects were observed when sensitization was begun 19 days after PI-3 virus inoculation. The mechanism(s) responsible for the attenuated responses to antigen in PI-3 infected animals are unknown but may involve virus-induced effects on immune cells.     

Delayed-type hypersensitivity reaction in the lungs of guinea pigs due to potassium dichromate

Potassium dichromate was inhaled by guinea pigs previously immunized by potassium dichromate until strong positive patch tests were obtained. No obvious respiratory changes were noted during and after inhalation. Histologically, however, mononuclear cells infiltrated the interstitial spaces in large areas of the lung, producing considerable thickening of the alveolar spaces in 24 to 48 hr after inhalation. Polymorphonuclear cells were predominant initially. These changes were similar to the delayed-type hypersensitivity reaction in the lung elicited by the inhalation of purified protein derivative (PPD) in the guinea pigs immunized by an injection of dry-killed tubercle bacilli. A less marked reaction was observed in guinea pigs passively sensitized with peritoneal exudate cells and lymph node cells. Consequently, the pulmonary changes were thought to be elicited by delayed-type hypersensitivity reaction due to a simple chemical. The clinical implications of delayed-type hypersensitivity reaction in the lung due to simple chemicals are discussed.     

Activation and release of enzymes and major basic protein from guinea pig eosinophil granulocytes induced by different inflammatory stimuli and other substances

In order to investigate the availability and release of enzymes from eosinophilic granulocytes in response to a variety of stimuli, guinea pig peritoneal eosinophils were obtained after repeated intraperitoneal injections of freeze-driedTrichinella spiralis larvae. The activities of the enzymes peroxidase, arylsulfatase B,-glucuronidase, aminopeptidase, histaminase, cytochromec oxidase, acid phosphatase, adenosine triphosphatase and glucose 6-phosphatase, and the major basic protein (MBP) were studied histochemically and, in part, also biochemically. Eosinophiis were incubated with the following substances: histamine. platelet activating factor, calcium ionophore, compound 48/80, leukotriene B₄, prostaglandins E₁, and E₂, heparin, and eosinophii-chemotactic factors from neutrophils and lymphocytes. Eosinophils displayed a selective and stimulus-dependent enzyme and MBP reaction. Calcium ionophore and compound 48/80 provoked a release of cytotoxic major basic protein, partly associated with peroxidase release, while leukotriene B₄ and eosinophil chemotactic factors caused histaminase and peroxidase release and activated leucinaminopeptidase. Heparin and calcium ionophore induced release of both MBP and histaminase. These data support the concept that eosinophils exhibit either inflammatory or cytotoxic, or antiinflammatory properties upon stimulation by various agents.     

Elevated histaminase (diamine oxidase) activity in small-cell carcinoma of the lung.

To investigate the possible embryologic relation between small-cell carcinoma of the lung and medullary thyroid carcinoma, we measured plasma histaminase (an enzyme found in medullary carcinoma tissue) in 25 patients with small-cell tumors. The assays used histamine and putrescine as substrates. Thirty-two per cent of the patients by the histamine assay, and 31 per cent by the putrescine, had values greater than +2 S.D. from the mean for 63 normal persons. In contrast, among 20 patients with squamous and large-cell lung tumors, one (by the histamine assay), and two (by the putrescine) had elevated values. In four of five autopsy cases, histaminase was high in small-cell carcinoma tissue. The enzyme in plasma and in tumor behaved as classic histaminase in substrate specificity, and in response to inhibitors. The data support the proposed embryologic relation between small-cell lung carcinoma and medullary thyroid carcinoma, and further associate histaminase with some neural crest tumors.     

Histaminase activity in rat lung and its comparison with intestinal mucosal diamine oxidase

In rat lung microsomes, an enzyme showing high histaminase activity is present. The oxidation of histamine is dependent on the presence of two enzymic activities, both inhibited by alpha-aminoguanidine and by B24, an inhibitor of semicarbazide-sensitive amine oxidases (SSAO) which have benzylamine as preferential substrate. These enzymic activities differ in substrate specificity: one appears to be a classical tissue bound SSAO enzyme with high affinity for benzylamine, the other a diamine oxidase (DAO) with properties that are very different from the classical DAO. This latter enzyme is not inhibition by high histamine concentrations and is more active at pH 8.5 than at pH 7.4.     

Bronchial hyperreactivity to histamine induced byHaemophilus influenzae vaccination

Bronchial hyperreactivity to histamine 4 days following vaccination with the human respiratory pathogenHaemophilus influenzae was tested in twoin vivo and onein vitro models. Conscious vaccinated guinea pigs exposed to aerosolized histamine became asphyxial significantly faster than saline-treated controls. Also the bronchoconstriction in anaesthetized guinea pigs as a result of i.v. histamine was significantly potentiated in theH. influenzae pretreated group. Isoprenaline (30g/kg) partially inhibited the bronchoconstriction. The difference in histamine sensitivity between the two groups however remained. Protection against bronchoconstriction by atropine on the other hand was significantly enhanced in the vaccinated animals. This suggests a hyperreactivity of the parasympathetic, cholinergic pathways as a result ofH. influenzae vaccination.To whom correspondence should be addressed.     

Hydrolase and oxidoreductase activities in peripheral blood lymphocytes in combined exposure to biological allergens and sulfur dioxide

Differences in the metabolic status of peripheral blood lymphocytes were observed after exposure of intact guinea pigs and animals sensitized with biological allergens to sulfur dioxide. When sensitization was complicated by chemical exposure, enzyme activities in lymphocytes depended on the type of allergen and degree of hypersensitivity. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 141, No. 2, pp. 221–224, February, 2006     

Effect of amlexanox on experimental allergic rhinitis in actively sensitized guinea pigs

The effect of amlexanox given orally for 3 weeks was studied on the IgE-mediated experimental allergic rhinitis in the actively sensitized guinea pigs. The intranasal instillation of antigen (egg albumin) induced the increase of nasal vascular permeability (dye leakage), histamine content in nasal perfusate and nasal resistance in sensitized guinea pig. Amlexanox, 20 and 60 mg/kg/day given orally for 3 weeks significantly inhibited the increase of dye leakage into the nasal cavity, histamine content and nasal resistance in a dose-dependent manner. These results suggest that amlexanox given orally may be useful therapeutic agent for human allergic rhinitis.     

Is the airway epithelium responsible for histamine metabolism in the trachea of guinea pigs?

The aim of the study was to investigate whether or not the epithelium plays an active role in histamine metabolism, via the histaminase and/or methyltransferase pathways. Isolated tracheas from guinea pigs sensitized to egg albumin (EA) were used. The epithelium was either left intact or removed from the preparations. The tracheal tubes were mounted in a chamber, allowing estimation of smooth muscle tension, and perfused with buffer. In some experiments the perfusate was collected for determination of histamine and methylhistamine.Mepyramine was used to evaluate the contribution of histamine to the EA-induced contraction. Mepyramine reduced the contraction by 90% when the epithelium was removed; with intact epithelium the reduction was 47%. Aminoguanidine, a histaminase inhibitor, significantly potentiated the response to EA when the epithelium was left intact.Traces of methylhistamine were detected in tissue extracts and perfusates. We conclude that histaminase is present in the preparation and that it can contribute to the inhibitory effect of the epithelium by means of histamine degradation.     

Toluene diisocyanate-induced airway hyperreactivity and pathology in the guinea pig

We assessed the nature and progression of airway mucosal disease and histaminic reactivity in English short-haired guinea pigs at 2, 24, 72, 168, and 504 hours after toluene diisocyanate (TDI) exposure (4 hours of 3 ppm of TDI for 5 consecutive days). To also determine whether TDI-specific, IgE-like antibodies developed in TDI-exposed animals, passive cutaneous anaphylaxis testing was done 28 days after TDI. Bronchial reactivity was determined serially by measuring specific airway conductance as a function of increasing doses of aerosolized histamine in six exposed and three control animals studied intact and unanesthetized. The remaining 10 exposed and 10 control guinea pigs were sacrificed in groups of two at each time point to obtain airway tissue for light microscopic examination. We found that airway hyperreactivity to histamine occurred after TDI in all animals tested. It was maximal 2 hours after the 5-day exposure and remitted by 72 hours. In addition, marked airway obstruction occurred after TDI that persisted for at least 168 hours. There were dramatic signs of airway mucosal damage associated with the bronchial hyperreactivity that included substantial decreases in epithelial cilia, mucin content, and mast cells, as well as squamous metaplasia, numerous mitotic figures, and a prominent polymorphonuclear leukocytic infiltrate. Passive cutaneous anaphylaxis tests in exposed animals were negative. Our results suggest that TDI-induced bronchial hyperreactivity may be related to airway mucosal injury and inflammation.