Abstract
Asthmatic patients are hypersensitive to the cough-provoking effect of hypertonic aerosols. 15- hydroxyeicosatetraenoic acid (15(S)-HETE) and leukotriene (LT) B4 are asthma-related mediators which can be released upon hypertonic stimuli, and both are potent agonists of the transient receptor potential vanilloid subfamily member 1 (TRPV1), a major cough receptor. Therefore, they are potential mediators for hypertonicity-provoked cough.
Twenty-six asthmatic and ten healthy subjects underwent a hypertonic saline cough provocation test. Exhaled breath condensate was collected before and after the test, and the concentrations of 15(S)-HETE and LTB4 were analysed.
Neither the baseline concentrations of these mediators nor the saline test-induced changes in them were associated with cough responsiveness to hypertonicity. High baseline 15(S)-HETE was associated with aspirin hypersensitivity and high LTB4 with male sex and large variability in ambulatory peak flow measurements.
The TRPV1 agonists 15(S)-HETE and LTB4 seem not to be involved in the cough response to hypertonicity in asthmatic patients.
Keywords: 15-hydroxyeicosatetraenoic acid, asthma, chronic cough, cough mechanisms, hypertonic saline, leukotriene B4, TRPV1, hypertonicity, Cough Provocation Test, Cough Receptor
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