Abstract |
The role of platelet-activating factor (PAF) in Ag-induced airway hyperresponsiveness was evaluated in a guinea pig model using the PAF antagonist SDZ 64-412. Repeated OVA challenge by aerosol (twice weekly x 4 wk) of previously sensitized guinea pigs produced striking airway hyperresponsiveness as determined by pulmonary resistance changes to increasing doses of inhaled acetylcholine given 3 days after the last OVA challenge. Each OVA challenge produced significant hypoxia that was unaffected by oral pretreatment with 20 mg/kg SDZ 64-412, 2 h before each challenge (pO2 = 35 +/- 2 mm Hg for OVA alone vs 40 +/- 6 mm Hg for SDZ and OVA groups, respectively). SDZ 64-412 pretreatment abolished the airway hyperresponsiveness resulting from repeated Ag challenge. Morphometric analysis revealed that SDZ 64-412 treatment had no effect on the increased numbers of eosinophils that infiltrated the airways of OVA-challenged guinea pigs. These results suggest that PAF may be a primary mediator of airway hyperresponsiveness, but not acute bronchoconstriction, induced by repeated Ag challenge. This activity of PAF appears independent of eosinophil recruitment to airways.
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Authors | K Ishida, R J Thomson, L L Beattie, B Wiggs, R R Schellenberg |
Journal | Journal of immunology (Baltimore, Md. : 1950)
(J Immunol)
Vol. 144
Issue 10
Pg. 3907-11
(May 15 1990)
ISSN: 0022-1767 [Print] United States |
PMID | 2332636
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Isoquinolines
- Platelet Activating Factor
- SDZ 64-412
- Ovalbumin
- Acetylcholine
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Topics |
- Acetylcholine
(immunology)
- Airway Resistance
- Animals
- Bronchial Provocation Tests
- Bronchial Spasm
(physiopathology)
- Connective Tissue Cells
- Eosinophils
(immunology)
- Epithelial Cells
- Guinea Pigs
- Hypersensitivity
(physiopathology)
- Isoquinolines
(pharmacology)
- Ovalbumin
(immunology)
- Platelet Activating Factor
(antagonists & inhibitors)
- Platelet Aggregation
- Respiratory System
(cytology)
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