A comparison of histamine secretion from peritoneal mast cells of the rat and hamster.

Functional mast cells have been obtained by peritoneal lavage of the rat and hamster. Both cell types released histamine on stimulation with appropriate dilutions of anti-rat IgE and anti-hamster serum. The maximum response evoked by each reagent was significantly greater for the hamster cells. The release was non-cytotoxic and was in each case blocked by the corresponding soluble antigen. The rat and hamster cells responded to concanavalin A and the lectin from lentil. Phosphatidylserine (PS) potentiated the release only from the rat cells. In the absence of the lipid, the hamster cells were more reactive. The lectin from wheat germ, in the presence of PS, evoked histamine secretion only from the rat cells. Both populations were refractory to the lectin from soybean and to protein A. Rat peritoneal cells were more responsive to the basic secretagogues compound 48/80 and peptide 401 (the MCD-peptide from bee venom). These differences were less marked in the case of polylysine and polyarginine. The two cell populations responded to the calcium ionophores A23187, ionomycin and chlortetracycline. The hamster cells were significantly more sensitive to the former two liberators but markedly less reactive to chlortetracycline. Adenosine 5'-triphosphate (ATP) and dextran were potent histamine liberators from the rat cells but were totally ineffective against the hamster. Acetylcholine and carbamylcholine had no effect on either cell type. These results are discussed in terms of the functional heterogeneity of mast cells from different sources.

Lamina propria mast cells in biopsies from children with Crohn's disease.

Biopsies from actively inflamed areas of terminal ileum or colon in children with Crohn's disease were examined both for lamina propria mast cell density and histamine content. These were reduced in comparison with those of normal controls. The release of histamine from biopsies of inflamed tissue did not differ greatly from that of normal tissue, either spontaneously or after receiving an antihuman IgE challenge.

Differential effects of anti-allergic compounds on peritoneal mast cells of the rat, mouse and hamster.

The effects of various inhibitors and anti-allergic drugs on histamine secretion from peritoneal mast cells of the rat, mouse and hamster have been compared. Phosphodiesterase inhibitors, cAMP analogues and beta-adrenoceptor agonists variously blocked release of the amine from all three cell types. The mouse cells were rather less sensitive to the former agents than those of the rat and hamster. Disodium cromoglycate inhibited histamine secretion from rat peritoneal mast cells, was less active against the hamster cells and completely ineffective against those of the mouse. Other chromones showed varied patterns of differential reactivity but phloretin and the flavonoid quercetin were essentially equiactive against all three cell types. The tetrazoles AH 9679 and doxantrazole prevented histamine release in each case but were significantly less active against the mouse cells. These results further emphasize the functional heterogeneity of mast cells from different sources.

Comparison of the histamine-releasing action of substance P on mast cells and basophils from different species and tissues.

The action of the neuropeptide substance P as a histamine-releasing agent has been compared in histamine-containing cells from a variety of different tissues and species. Peritoneal mast cells from rat, mouse and hamster but not human cells gave a concentration-dependent release of histamine in response to substance P. Release was greater in the absence than in the presence of calcium in the extracellular medium. Mast cells from rat mesentery, lung and heart released histamine in response to substance P, but heart mast cells responded only weakly. All guinea-pig mast cells and histamine-containing cells from human tissues did not give any substantial substance-P-induced release of histamine. The data provides further evidence for the functional heterogeneity of histamine-containing cells.

Basophil histamine release. A study in allergy to suxamethonium.

A patient who suffered a severe hypotensive episode after induction of anaesthesia, was subsequently found to show positive skin-test responses to suxamethonium. Investigation revealed that suxamethonium induced basophils from the patient to release histamine to an extent comparable to that found after exposure to anit-IgE. Basophils from control subjects showed no such response. Basophil histamine release may offer a useful approach to the investigation of adverse drug reactions.

Guinea pig mast cells: comparative study on morphology, fixation and staining properties.

We have studied the distribution of mast cells (MC) in different tissues of the guinea pig (GP), and certain aspects of their histochemical and cytochemical properties. In preparations fixed with Carnoy's fluid, MC were extremely well-preserved and were detected in all tissue sections and cytocentrifuge smears obtained from enzymically dispersed cells after staining with alcian blue at pH 0.5-2.2. In formol-saline-fixed preparations, there was a substantial reduction in MC counts. Most of the tissue MC were located interstitially and in the perivascular connective tissue. A small proportion of MC was located in certain organ- or tissue-specific structures. When counted manually, MC comprised 0.43-3.1% of the cell population obtained by enzymic dispersion. This proportion was higher than that obtained by the automated Technicon H6000 basophil system, but the two counting systems confirmed organ differences in MC counts. MC in different GP tissues varied in size, morphology, histamine content and degree of susceptibility to formol-saline fixation. The granules of GP connective tissue MC differed from those of rat peritoneum in failing to take the fluorescent stain berberine sulphate which has greater affinity for the highly sulphated glycosaminoglycans such as heparin, and in having some morphological and histochemical similarity to 'mucosal' MC.

Cardiac and renal mast cells: morphology, distribution, fixation and staining properties in the guinea pig and preliminary comparison with human.

In guinea pig (GP) and human heart and kidney cell or tissue preparations fixed with Carnoy's fluid (but not with formol-saline), mast cells (MC) were extremely well preserved and could be detected after staining with alcian blue (AB). Although histamine content and distribution in GP and human heart appeared to be different, morphological and histochemical studies of MC suggested a similarity between the two species and a clear distinction from rat peritoneal MC.

Some studies on the isolation and properties of pulmonary mast cells from the pig.

Mast cells were isolated by the enzymic dissociation of lung tissue from the pig. The responses of these cells to a variety of histamine liberators and anti-allergic drugs were examined. On the basis of these findings, the possible use of porcine pulmonary mast cells in the study of immediate hypersensitivity reactions is discussed.

The function and properties of human lung mast cells.

Mast cells may be recovered from human subjects by bronchoalveolar lavage. Such bronchoalveolar mast cells will release histamine in response to IgE-dependent challenge in a reaction that is dose-, time- and energy-dependent. They possess functional characteristics distinct from dispersed human lung mast cells. The percentage of mast cells within the bronchoalveolar cell population is critically dependent upon the underlying pathology. Greater numbers of mast cells may be recovered from the bronchoalveolar compartment of extrinsic asthmatics than from controls. In addition, bronchoalveolar mast cells from asthmatic subjects show an increased releasability of histamine in response to anti-IgE. Antigen challenge also leads to the release of histamine in vitro, demonstrating the potential for the antigen-specific initiation of bronchoconstriction in these subjects. Spontaneous release of histamine from bronchoalveolar mast cells of asthmatic subjects was also greater than in controls (up to 46%), a feature which may be related to non-immunological mechanisms of bronchoconstriction. Such non-immunological mechanisms have been further investigated utilising mannitol as a model of hyperosmolar histamine release. Mannitol induced a dose-dependent release of histamine from bronchoalveolar mast cells of normal subjects, and this release was significantly inhibited by sodium cromoglycate. The leukotrienes are putative major mediators of human asthma. After challenge with anti-IgE in vitro, dose-dependent release of leukotriene C4 and prostaglandin D2 occurs from the bronchoalveolar cells of normal subjects. The release of PGD2 shows significant correlation with histamine release. Lying superficially, bronchoalveolar mast cells would be readily accessible to inhaled antigen. Mediator release from such cells may be relevant to the pathogenesis of asthma.

A comparison of nedocromil sodium and sodium cromoglycate on human lung mast cells obtained by bronchoalveolar lavage and by dispersion of lung fragments.

Bronchoalveolar lavage (BAL) mast cells provide a useful tool with which to screen potential therapeutic agents for human airway diseases. This study was therefore designed to compare the activity of nedocromil sodium and sodium cromoglycate in inhibiting anti-IgE induced histamine release from human mast cells obtained by BAL and from dispersed lung (DL) fragments. After 10 min pre-incubation with the mast cell preparations, both drugs displayed greater inhibition of histamine release from BAL than from DL mast cells. Under optimal conditions of 10 min pre-incubation with BAL and none with DL mast cells, nedocromil sodium showed significantly more activity than sodium cromoglycate on both BAL and DL mast cells.

Some properties of mast cells obtained by human bronchoalveolar lavage.

The properties of human pulmonary mast cells obtained by enzymic dispersion of whole lung and by bronchoalveolar lavage (BAL) have been compared with those of the basophil leucocyte. The latter cell types responded with release of histamine to challenge with anti-human IgE but the dispersed cells reacted only after passive sensitisation with serum from an atopic donor. Disodium cromoglycate inhibited the release of histamine from both types of pulmonary mast cell although the characteristics of the inhibition were different in the two cases. The drug was ineffective against the basophil. Increased numbers of mast cells were recovered by lavage of asthmatic subjects and these cells responded to immunological challenge with an enhanced release of histamine. The possible clinical significance of these findings in human bronchial asthma is discussed.

Human mast cells recovered by bronchoalveolar lavage: their morphology, histamine release and the effects of sodium cromoglycate.

Mast cells make up between 0.5 and 3% (mean 1.35%) of total cells recovered by bronchoalveolar lavage (BAL). The majority of these cells have the morphological characteristics of mucosal mast cells in that they fail to stain in the alcian blue-safranin reaction after fixation in formol-saline but stain well after fixation in Carnoy's solution. Cells staining with berberine sulphate were seen in only four of the 26 lavages. BAL cells released histamine in response to anti-human immunoglobulin E (IgE) in a dose-dependent manner that was optimal at a dilution of anti-IgE of 1:100. Maximum release was obtained by 2 min. Histamine release was completely inhibited by a combination of 2-deoxyglucose (5 mmol/l) and antimycin A (1 mumol/l). Disodium cromoglycate (DSCG) significantly inhibited this histamine release at 1 mmol/l (P less than 0.02), 100 mumol/l (P less than 0.002) and 10 mumol/l (P less than 0.003), with maximum inhibition of 50.1% at 10 mumol/l.

Bronchoalveolar mast cells in extrinsic asthma: a mechanism for the initiation of antigen specific bronchoconstriction.

Bronchoalveolar lavage performed in 10 patients with extrinsic asthma and 14 controls yielded similar recoveries of fluid and cells. Mast cells and eosinophils, however, formed a greater proportion of the cells recovered from the asthmatic subjects (p less than 0.001 for mast cells; p less than 0.01 for eosinophils), the histamine content of the lavage cells being correspondingly increased (p less than 0.01). Both the percentage of mast cells and the histamine content of lavage cells were significantly inversely correlated with the forced expiratory volume in one second (FEV1; expressed as percentage of predicted) and with the ratio of FEV1 to forced vital capacity before lavage. There was also a significant inverse correlation between the concentration of histamine required to produce a 20% fall in FEV1 and the percentage of mast cells recovered (p less than 0.05). When incubated with antihuman IgE bronchoalveolar mast cells from asthmatic subjects released a significantly increased proportion of total cellular histamine than cells from control subjects at all effective doses of anti-IgE. By contrast, dose response curves for IgE dependent histamine release from peripheral blood leucocytes were similar in asthmatics and controls. Specific antigen led to release of histamine from bronchoalveolar cells and peripheral blood leucocytes of asthmatic subjects but not controls. Lying superficially within the airways, bronchoalveolar mast cells would be readily exposed to inhaled antigen and would release mediators directly on to the airway surface. Their immunological response suggests that they are likely to be important in the pathogenesis of airflow obstruction in asthma.

Some further properties of human pulmonary mast cells recovered by bronchoalveolar lavage and enzymic dispersion of lung tissue.

The properties of human pulmonary mast cells obtained by bronchoalveolar lavage (BAL) and enzymic dispersion of lung tissue have been compared with those of basophil leucocytes. On challenge with anti-human IgE, the pulmonary cells released both histamine and the newly generated mediators prostaglandin D2 (PGD2) and leukotriene C4 (LTC4). In contrast, the blood leucocytes released histamine but very little leukotriene and no prostanoid. Interestingly, both basophil leucocytes and BAL cells released histamine spontaneously in a hyperosmolar environment whereas dispersed lung (DL) cells showed limited reactivity under these conditions. The possible clinical significance of these findings in human bronchial asthma is discussed.

Some studies on human pulmonary mast cells obtained by bronchoalveolar lavage and by enzymic dissociation of whole lung tissue.

Human pulmonary mast cells were obtained by bronchoalveolar lavage (BAL) and by enzymic dissociation of whole lung. The cells released histamine on immunological stimulation or on exposure to a hyperosmolar environment. Cell suspensions similarly released newly generated products of arachidonic acid metabolism. Increased numbers of mast cells were recovered by BAL of asthmatic subjects and patients suffering from sarcoidosis and these cells were hyperresponsive to immunological challenge. Mast cells recovered by BAL and enzymic dissociation were differentially inhibited by antiasthmatic drugs. These data emphasize the potential role of BAL mast cells in pulmonary diseases of diverse origin.

Effects of sodium cromoglycate and nedocromil sodium on histamine secretion from human lung mast cells.

Sodium cromoglycate and nedocromil sodium produced a dose dependent inhibition of histamine secretion from human pulmonary mast cells obtained by bronchoalveolar lavage and by enzymatic dissociation of lung parenchyma. Both compounds were significantly more active against the lavage cells than against the dispersed lung cells, and nedocromil sodium was an order of magnitude more effective than sodium cromoglycate against both cell types. Tachyphylaxis was observed with the parenchymal cells but not with the lavage cells. Nedocromil sodium and sodium cromoglycate also inhibited histamine release from the lavage cells of patients with sarcoidosis and extrinsic asthma.

Bronchoalveolar mast cells in sarcoidosis: increased numbers and accentuation of mediator release.

Bronchoalveolar lavage was carried out in 36 subjects with sarcoidosis and 20 control subjects undergoing bronchoscopy for routine diagnostic purposes. The proportion of mast cells in the lavage fluid of subjects with sarcoidosis (mean (SE) 0.84% 0.09%; p less than 0.01) when compared with that of controls (mean 0.32% (0.05%); p less than 0.01). This increase was greatest in subjects with positive gallium scans but was not correlated with the percentage recovery of lymphocytes or radiographic stage. Anti-IgE induced histamine release from the bronchoalveolar cells of 15 subjects with sarcoidosis was significantly increased at all effective doses of anti-IgE. This accentuation of histamine release was significantly greater in patients with positive gallium scans and correlated directly with the percentage recovery of lymphocytes (r = 0.7, p less than 0.005). The dose-response curve of anti-IgE induced histamine release from bronchoalveolar cells of subjects with more than 20% of lymphocytes in the lavage cell population was significantly greater than the dose-response curves of subjects with fewer than 20% of lymphocytes and of controls.