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Biomedical subjects

W Schmutzler

Publications and source records attributed to W Schmutzler.

At least 55 records · Page 3Linked to original sources
PubMed1982

Comparative studies of mast cells from normal (non-immunized) and actively sensitized dogs.

Morphologically and functionally intact mast cells were isolated from the lung and mesentery of normal or actively sensitized dogs using the pronase or collagenase tissue dissociation methods. The latter method yielded about 6 times as many metachromatically staining cells. Electron microscopic examination revealed the presence of both mast cells and basophils in all samples, independent of the enzyme used for tissue dissociation. The average histamine content of the cells obtained with the pronase method was significantly higher (21.8 +/- 3.1 pg) than after collagenase treatment (16.2 +/- 4.2 pg). There was no appreciable difference in the reactivity to secretory stimulation of the cells obtained by the two methods. The cells isolated from actively sensitized dog tissues showed a significantly higher spontaneous histamine release (12.9 +/- 1.2%) than those from non-sensitized animals (7.8 +/- 1.3%) and responded equally well to challenge with both the antigens ovalbumin and horse serum. In contrast to those from normal animals, the mast cells from actively sensitized dogs released histamine on stimulation with acetylcholine, metacholine or atropine. In addition, the response to the threshold concentration of compound 48/80 (10(-6)) was significantly stronger in the sensitized cells. Small molecular polyvinylpyrrolidone (K25) was effective in mast cells from normal and actively sensitized dogs.

Acetylcholine↗
PubMed1981

Histamine release from isolated mast cells as a bioassay system for the standardization of allergens.

Standardization of allergen extracts is still a problems not yet satisfactorily resolved. Allergic sensitization involves not only the production of allergen-specific antibodies of a certain class (IgE) but also changes in the morphological and functional state of the mast cells that bind and carry IgE and react with the allergen. We therefore designed a bioassay which covers the total allergenicity and also antibody-independent allergen effects. It is based on the release of histamine from isolated mast cells of actively sensitized guinea pigs: outbred animals receive one s.c. injection of the allergen extract to be tested and human serum albumin (HSA) as reference (standard) allergen. Three weeks later the mesenteric mast cells of these animals are isolated and challenged in vitro with varying concentrations of the test allergen and HSA. The relationship of the histamine release caused by the reference allergen HSA to that caused by the test allergen (e.g. rye or grass pollen, alternaria, and even house dust) can be used to estimate the sensitizing and challenging potency of the test allergen. For example, 2 different batches of rye pollen gave different results although the values obtained by identical batches were almost identical within 9 months. In addition, irritating impurities of the allergen extract might be recognized.

Allergens↗
PubMed1981

Inhibition by azelastine of the immunologically induced histamine release from isolated guinea pig mast cells.

4-(p-Chlorobenzyl)-2-(hexahydro-1-methyl-1H-azepin-4-yl)-1-(2H)-phthalazinone (azelastine, A 5610) did not affect the spontaneous histamine release but inhibited effectively the allergic histamine release from isolated mesenteric mast cells of actively sensitized guinea pigs. At 10(-6) mol/l concentration the inhibition was almost equal to that caused by adrenaline (10(-8) mol/l).

Animals↗
PubMed1978

Studies on the release of histamine from isolated guinea pig mast cells stimulated by ionophore A23187 or by the anaphylactic reaction.

The divalent cation ionophore A23187 was found to produce a dose-dependent release of histamine from isolated mesenteric mast cells of the guinea pig. The process showed a specific requirement for calcium ions and was blocked by inhibitors of glycolysis. The effect of cAMP, theophylline, sympathomimetic amines and DSCG on the histamine release induced by the ionophore or by the antigen-antibody reaction was compared. In both cases, the release was inhibited by Bu2cAMP and by theophylline but higher concentrations were required with the ionophore. Adrenaline, isoprenaline and DSCG were effective only in the anaphylactic system. These results are compared with those previously reported for human leucocytes and rat peritoneal mast cells in which the release produced by the ionophore was found not to be inhibited by cAMP and its analogues. On the basis of these findings, the possible role of cAMP in the modulation of histamine release is discussed.

Anaphylaxis↗
PubMed1978

Ultrastructure of isolated human mast cells during histamine release induced by ionophore A 23187.

In the presence of calcium, the ionophore A 23187 (10(-7) TO 10(-6) M) causes a dose-dependent histamine release from isolated human mast cells. The accompanying degranulation process is characterized by a formation of channels of fused mast cell granules and by an exocytotic extrusion of altered granule material. Simultaneously, large numbers of newly formed 70 A filaments occur. These filaments probably have a key function in secreting human mast cells.

Anti-Bacterial Agents↗
PubMed1977

[The demonstration of pharmacological active substances in the portal vein blood of dogs after occlusion of the superior mesenteric artery (author's transl)].

The experimental occlusion of the superior mesenteric artery in dogs is followed by a significant rise of serotonin-, kinin- and katecholamin-concentrations in the portal vein blood. The rise of the prostaglandin-F2alpha-concentration occurred only immediately after the occlusion or reopening of the occluded superior mesenteric artery. Under our experimental conditions the measured concentrations of these substances in the portal vein blood are too low and ineffective for the development of peptic erosions in the stomach as observed after occlusion of the superior mesenteric artery. On the other hand a possible additiv effect of the underswelling concentrations in these different substances cannot be excluded.

Animals↗
PubMed1977

Isolation and study of functional mast cells from lung and mesentery of the guinea pig.

A method is described for the dissociation of guinea pig lung and mesentery into their component cells. The method comprises incubation of the tissues with the enzyme pronase in Ca++- and Mg++-free saline followed by mechanical dispersion and yields on average 3-8% free mast cells. These cells are morphologically intact and viable. They retain an active sensitization or can be passively sensitized. The levels of cAMP and cGMP in the whole cell suspension respond to catecholamine, histamine or cholinergic stimulation in a way similar to that observed in the corresponding undispersed tissue. Although the separation of guinea pig mast cells from other cells proved to be more difficult than the purification of rat mast cells, an inrichment of greater than 50% has been achieved. The mast cells isolated by this method proliferate in vitro and have been cultured successfully for several months.

Anaphylaxis↗