Sham ICS1 ICS2 ICS4 LABA1 LABA2 LABA4 TT (N/cm2) 4.2 ± 0.4 4.3 ± 0.5 4.0 ± 0.3 4.0 ± 0.6 4.4 ± 0.3* 4.3 ± 0.3* 4.6 ± 0.4* CT (msec) 39.4 ± 1.9 34.3 ± 1.7* 32.4 ± 1.5** 42.1 ± 2.0 34.8 ± 3.3 41.1 ± 1.8 36.1 ± 1.8 HRT (msec) 45.0 ± 4.6 34.2 ± 2.7*** 36.9 ± 2.9** 54.0 ± 5.3 44.9 ± 6.8 50.5 ± 6.2 40.1 ± 2.9 Fatigue (%) 39.9 ± 3.6 33.4 ± 2.7 32.5 ± 2.2 36.8 ± 2.4 33.4 ± 1.9 37.9 ± 2.4 36.6 ± 2.4 TT/CT (N/cm2/sec) 95.3 ± 13.3 127.4 ± 13.9 125.2 ± 8.0 93.5 ± 10.9† 129.0 ± 9.9 106.8 ± 9.0 131.0 ± 15.6 (TT/2)/HRT (N/cm2/sec) 43.0 ± 7.2 64.9 ± 7.8 55.6 ± 3.0 39.0 ± 5.6†† 55.8 ± 7.6 45.9 ± 4.6 58.9 ± 5.6

ICS1, ICS2, and ICS4 express 1 h, 2 h, and 4 h after ICS inhalation. LABA1, LABA2, and LABA4 express 1 h, 2 h, and 4 h after LABA inhalation. TT, twitch tension; CT, contraction time; HRT, half-relaxation time. *p < 0.05, **p < 0.01, ***p < 0.001 compared with sham. †p < 0.05, ††p < 0.01 compared with each value at ICS1.

Table 1. Changes in twitch kinetics in the sham, ICS inhalation-only, and LABA inhalation-only groups