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Pulmonary function and histaminemia after polymyxin B inhalation
Agents and Actions
|April 1, 1981
Summary
Polymyxin B triggers bronchoconstriction in most atopic asthmatics by causing mast cell degranulation. This process releases histamine, increasing blood histamine levels and confirming its role in asthma symptoms.
Area of Science:
- Pulmonary Medicine
- Immunology
- Pharmacology
Background:
- Atopic asthma involves airway hyperresponsiveness.
- The role of histamine in asthma pathogenesis is significant.
- Polymyxin B's effect on asthmatic airways requires clarification.
Purpose of the Study:
- To investigate the mechanism of polymyxin B-induced bronchoconstriction in atopic asthmatics.
- To determine the relationship between polymyxin B challenge, histamine release, and bronchoconstriction.
- To elucidate the role of mast cell degranulation in this response.
Main Methods:
- Administering polymyxin B via bronchial challenge to atopic asthmatic subjects.
- Monitoring for bronchoconstriction using pulmonary function tests.
- Measuring blood histamine levels (histaminemia) before and after challenge.
Main Results:
- 85% of atopic asthmatics experienced significant bronchoconstriction upon polymyxin B challenge.
- Increased histaminemia was observed in all subjects with polymyxin B-induced bronchoconstriction.
- No increase in histaminemia occurred when bronchoconstriction was absent.
Conclusions:
- Polymyxin B-induced bronchoconstriction in atopic asthma is exclusively mediated by mast cell degranulation.
- Histamine released locally in the bronchi can lead to elevated systemic histamine levels.
- This study provides evidence for histamine's critical role in polymyxin B-induced airway inflammation.