Methods: Eight patients with asthma and EIB and five normal controls without EIB were enrolled. Exercise challenge tests comprised of 6 min of treadmill exercise or free running were performed in all study subjects, and urine samples before and 1 h after the challenge were collected. Urinary levels of 9α,11β-PGF2 and LTE4 were measured by enzyme immunoassay.
Results: No significant differences were observed in 9α,11β-PGF2 and LTE4 levels before/after the exercise challenge between patients with EIB and normal controls. No significant increases in urinary levels of 9α,11β-PGF2 or LTE4 were detected during the exercise challenge in patients with EIB and normal controls. No significant correlations were observed between the percent decrease in forced expiratory volume in 1 second or percent changes in 9α,11β-PGF2 and LTE4 levels after the exercise challenge.
Conclusions: Urinary 9α,11β-PGF2 and LTE4 levels did not increase after an exercise challenge in patients with EIB, suggesting that urinary excretion of 9α,11β-PGF2 and LTE4 may not be a good marker of mast cell activation in patients with EIB.
*** This study was supported by a grant from the Basic Science Research Program through the National Research Foundation of Korea (NRF), as funded by the Ministry of Education, Science, and Technology (2012R1A1A1012349).