Histamine In Lavage Fluid Research Articles

Effects of Multiple Dexamethasone Treatments on Aggravation of Allergic Conjunctivitis Associated with Mast Cell Hyperplasia

In a Japanese cedar pollen-induced allergic conjunctivitis model in guinea pigs, symptoms were aggravated by repeated pollen challenges. In addition, the number of mast cells in the conjunctiva was increased by multiple challenges. The amount of a mast cell mediator, histamine in ophthalmic lavage fluid was also increased by multiple challenges. In the present study, we evaluated the effects of multiple dexamethasone treatments to assess the relationship between the aggravation of symptoms and mast cell hyperplasia. Sensitized guinea pigs were challenged by dropping a pollen suspension onto their eye surface once a week until the 15th challenge. Dexamethasone (10 mg/kg, p.o.) was administered once 3 h before the 15th challenge or 3 h before every 1st--15th challenge. Mast cells in the conjunctival tissue were detected by toluidine blue staining. Histamine was fluorometrically assayed by high-performance liquid chromatography. Serum Cry j 1-specific IgE titer was measured by an enzyme-linked immunosorbent assay. The results indicated that a single treatment with dexamethasone did not affect the 15th challenge-induced symptoms; however, multiple treatments with the corticosteroid suppressed not only conjunctivitis symptoms after every challenge but also the mast cell hyperplasia and the increase in histamine in the lavage fluid. Conversely, the increase in the IgE titer in the serum was not affected by multiple treatments with dexamethasone. In conclusion, increased numbers of mast cells in the conjunctival tissue may be associated with the aggravation of allergic conjunctivitis symptoms.

The contribution of mast cells to the late-phase of allergic asthma in rats

Mast cells are thought to be the main cause of an immediate asthmatic response, but their contribution to the late-phase of asthma is unknown. To prove the contribution of preactivated mast cells to the late phase of allergic asthma by advanced activation. Mast cell function in the late-phase of asthma was studied. Rats (wild, +/+ and mast cell deficient, Ws/Ws) were challenged with OVA to investigate the relationship between the contraction of airways and the population of inflammatory cells in the trachea. During the entire asthmatic period, the contraction of the airway after OVA challenge in +/+ rats was enhanced significantly compared to Ws/Ws rats, especially in the late phase. The bronchoalveolar lavage fluid histamine in +/+, but not Ws/Ws, rats increased 5.3-fold in 30 min and 3.4-fold in 8 h after challenge, significantly. The number of mucosal mast cells in the tracheal epithelial layer in +/+ rats increased significantly 2.2-fold over controls at 8 h after challenge, as demonstrated by in situ hybridization. Mast cells may contribute to the late phase of asthmatic response by continuous mast cell activation and the mucosal mast cell number increased in the late phase of asthmatic response.

Asthma ‘Of Mice and Men’–How do animal models help us understand human asthma?

Asthma ‘Of Mice and Men’–How do animal models help us understand human asthma?

A lavage method for dynamic intraarticular monitoring of animal joints in situ: quantification and release kinetics of histamine after selective synovial mast cell activation by diverse secretagogues.

Evidence implicating synovial mast cells in the initiation and perpetuation of arthritis has increased. We have developed a method of joint lavage to monitor dynamic intraarticular events in the intact animal. Lavage was done before and after immunologic (passive sensitization followed by intravenous specific antigen or intraarticular anti-rat immunoglobulin E [IgE] heteroantiserum) and nonimmunologic (intraarticular calcium ionophore A-23187; phorbol 12-myristate, 13-acetate; and compound 48/80) synovial mast cell activation. To quantify and analyze synovial mast cell mediator release kinetics in situ, we measured lavage fluid histamine. With all activation protocols except A-23187, histamine release was evident within 5 minutes after introduction of the stimulus. The quantitative and chronological similarities between immunologically induced and compound 48/80-induced synovial mast cell histamine release kinetics suggested that connective tissue type mast cells are an important source of inflammatory mediators in rat joints. We also measured joint lavage fluid histamine levels in rats immunized with an active sensitization protocol. Histamine levels were determined by the autoanalyzer method and were confirmed by using a commercially available radioimmunoassay that uses a monoclonal antibody against acetylated histamine. We found that in many of these animals, at the peak of the serum IgE response, joint lavage fluid histamine levels were very high even before challenge with specific antigen, and that this increase was not due to diffusion into the joint of abnormally elevated plasma histamine. These data suggested that synovial mast cells are preferentially activated in states of high serum IgE immune responses. We have used a simple, inexpensive, rapid lavage technique to generate the first data on histamine release kinetics after selective synovial mast cell activation in the intact animal. The technique can be adapted for investigation of release kinetics of a variety of other substances from activated synovial cells and can be used in other arthritis models.

Elevated Bronchoalveolar Lavage Fluid Histamine Levels in Allergic Asthmatics Are Associated with Increased Airway Obstruction

Bronchoalveolar lavage (BAL) fluid was evaluated for histamine and tryptase levels in 61 samples (46 samples from 24 atopic asthmatics, seven samples from seven patients with allergic rhinitis, and eight samples from eight normal volunteers). Asthmatics and patients with allergic rhinitis had significantly higher BAL histamine than did normal subjects (169 +/- 22, 141 +/- 23, 42 +/- 6 pg/ml, respectively; p less than 0.05, both comparisons). BAL fluid tryptase levels were also higher in asthmatics and patients with allergic rhinitis than in normal subjects (0.36 +/- 0.03, 0.38 +/- 0.05, 0.23 +/- 0.04 ng/ml, respectively; p less than 0.05, both comparisons); however, levels of tryptase and histamine in BAL were not correlated (r = -0.03 in the group as a whole, r = -0.12 in the asthmatic group). BAL concentration of histamine correlated inversely with FEV1 percent predicted in the asthmatic group (r = -0.44, p less than 0.005). Asthmatics with high BAL fluid histamine (greater than or equal to 100 pg/ml, n = 23) had lower FEV1 percent predicted (80 +/- 3% versus 96 +/- 3%, p = 0.0005), lower FEV1/FVC ratio (72 +/- 1% versus 77 +/- 2%, p less than 0.05), higher percentage of BAL eosinophils (2.2 +/- 0.4% versus 0.6 +/- 0.1%, p less than 0.002), and greater airway responsiveness (lower PD20 [13.1 +/- 3.4 versus 41.5 +/- 13.7 cumulative breath units, p less than 0.05]) compared with asthmatics with low BAL fluid histamine (less than 100 pg/ml, n = 23).(ABSTRACT TRUNCATED AT 250 WORDS)

Role of mast cells in the pathogenesis of hypersensitivity pneumonitis.

To examine the possibility that mast cells have a central role in the pathogenesis of hypersensitivity pneumonitis, 20 patients with this disease were studied with the aim of seeking evidence for mast cell degranulation. The number of mast cells recovered by bronchoalveolar lavage from patients with hypersensitivity pneumonitis was more than 1,000 times greater than those recovered from normal individuals. Furthermore, discontinuation of antigen exposure resulted in an increase in the number of mast cells observed, consistent with the possibility that antigen exposure had induced mast cell degranulation. Cessation of antigen exposure also resulted in a rapid decrease in the number of neutrophils and eosinophils recovered by lavage, followed by an increase in the number of T8+ T lymphocytes present. In each case the time course of the changes was consistent with the possibility that mast cell degranulation had been important in regulating the number of the immune and inflammatory cells present in the lung. Histamine was present in lavage fluid supernatant from patients with hypersensitivity pneumonitis. The amount of histamine present was, however, closely correlated with the number of mast cells present and not with the interval since last antigen exposure. Delay in separating cells from lavage fluid supernatant resulted in an increase in histamine content. These results suggest that the free histamine in lavage fluid resulted from the degranulation of mast cells induced by the lavage procedure as histamine released in vivo has a short half life. We suggest that hypersensitivity pneumonitis results from a "late phase reaction" initiated by antigen induced mast cell degranulation.

Elevated bronchoalveolar lavage fluid histamine levels in allergic asthmatics are associated with methacholine bronchial hyperresponsiveness.

Using a sensitive single isotope enzymatic assay we measured bronchoalveolar lavage (BAL) fluid histamine in asymptomatic normal (nonallergic), allergic rhinitic, and allergic asthmatic subjects. Normal subjects were found to have little or no detectable amounts of histamine in BAL fluid (11 +/- 11 pg/ml), and few BAL fluid mast cells. In comparison, the allergic rhinitics and allergic asthmatics had much higher amounts of BAL fluid histamine (113 +/- 53 and 188 +/- 42 pg/ml, respectively), and a significantly greater number of BAL fluid mast cells. Furthermore, despite having equivalent baseline pulmonary function values, allergic asthmatics with BAL fluid histamine levels greater than 100 pg/ml required only 7 +/- 2 breath units of methacholine to induce a 20% drop in forced expiratory volume in 1 s (FEV1) (PD20FEV1) while asthmatics with BAL fluid histamine levels less than 100 pg/ml required 49 +/- 19 breath units (P less than 0.05). These data suggest that allergic asthmatics have ongoing lung mast cell degranulation that might contribute to the etiology of airway hyperresponsiveness.

Mast cell and histamine content of human bronchoalveolar lavage fluid.

Bronchoalveolar lavage was performed in 97 patients including control patients with bronchial carcinoma (24) and patients with sarcoidosis (20), cryptogenic fibrosing alveolitis (9), and asthma (4), and others. Cytocentrifuged slides were stained by two methods: May-Grünwald Giemsa and toluidine blue. In the last 32 subjects the bronchoalveolar lavage fluid was separated into supernatant and cell pellet for the subsequent assay of the performed mast cell mediator, histamine. Comparison of the two methods of staining showed a bias towards toluidine blue. Controls had a differential mean (SE) mast cell count of 0.07% (0.01%). Higher counts were noted in cryptogenic fibrosing alveolitis--0.61% (0.15%) (p less than 0.001)--and in sarcoidosis--0.14% (0.02%) (p less than 0.05). There was a strong correlation between absolute mast cell counts and cell lysate histamine concentration (r = 0.78, p less than 0.001). Less strong, significant, correlations between supernatant histamine concentration and absolute mast cell counts (r = 0.48, p less than 0.01) or cell lysate histamine concentration (r = 0.72, p less than 0.01) were also found. Derived mean values of histamine per mast cell ranged from 3.7 to 10.9 picograms. The mean histamine content of lavage fluid supernatant as a percentage of the total lavage fluid histamine was 24.9% (3.3%). The possible clinical significance of these findings is discussed.