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Platelet-activating factor-induced functional changes in the guinea pig trachea in vitro
1Department of Pediatrics, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Respiration Physiology
|August 1, 1989
Summary
Platelet-activating factor (PAF) exposure in guinea pigs caused airway hyperresponsiveness to histamine. This hypersensitivity in tracheal smooth muscle persisted for days, suggesting inflammation plays a role.
Area of Science:
- Respiratory Medicine
- Pharmacology
- Immunology
Background:
- Airway hyperresponsiveness is a hallmark of asthma.
- Platelet-activating factor (PAF) is implicated in inflammatory airway diseases.
Purpose of the Study:
- To investigate the role of PAF in airway hyperresponsiveness.
- To assess the effect of PAF on guinea pig tracheal smooth muscle sensitivity to various agonists.
Main Methods:
- Guinea pigs were challenged with aerosolized PAF for 7 days.
- Tracheal smooth muscle strips were used for isometric force measurements.
- Intracellular microelectrode studies and histological analyses were performed.
Main Results:
- PAF challenge led to increased histamine sensitivity in tracheal smooth muscle.
- Histamine's threshold concentration decreased significantly in PAF-treated animals.
- Histological examination revealed eosinophilic infiltration in the trachea.
Conclusions:
- In vivo PAF exposure induces in vitro hypersensitivity to histamine in guinea pig tracheal smooth muscle.
- Changes in excitation-contraction coupling and airway inflammation may contribute to PAF-induced hyperresponsiveness.