The impact of low-frequency, low-force cyclic stretching of human bronchi on airway responsiveness

Respiratory Research

Table 4 Effects of pretreatments on the stretch-induced change in potency of acetylcholine

		Cyclic stretch effect on Δ (−log EC₅₀), difference between control and stretch group		Effect of pretreatment	Effect size pretreatment
	n	in absence of pretreatment (log unit)	in presence of pretreatment (log unit)	(log unit)	\|d\| [95% CI]
Epithelium removal	13	0.48 ± 0.08^a	0.50 ± 0.14^b	0.02 ± 0.13	0.05 [−0.70–0.80]
Indomethacin (1 μM)	8	0.38 ± 0.07^a	0.32 ± 0.13^b	−0.05 ± 0.12	−0.23 [−1.20–0.76]
MK476 (1 μM)	7	0.41 ± 0.07^c	0.26 ± 0.23	−0.15 ± 0.24	−0.34 [−1.37–0.74]
L-NAME (1 mM)	14	0.30 ± 0.07^a	0.44 ± 0.05^a	0.14 ± 0.05	0.54 [−0.23–1.28]
Nicardipine (10 μM)	10	0.57 ± 0.10^a	0.11 ± 0.12	−0.45 ± 0.17^d	−1.26 [−2.16– − 0.25]
Tetrodotoxin (1 μM)	7	0.25 ± 0.05^c	0.38 ± 0.04^a	0.13 ± 0.06	1.12 [−0.07–2.16]
Gadolinium (0.1 mM)	8	0.27 ± 0.05^b	0.49 ± 0.08^a	0.22 ± 0.08^d	1.19 [0.07–2.18]
Tertiapine (10 μM)	9	0.40 ± 0.13^b	0.41 ± 0.09^c	0.03 ± 0.19	0.03 [−0.90–0.95]
Capsazepine (1 μM)	8	0.40 ± 0.11^c	0.54 ± 0.12^c	0.14 ± 0.15	0.41 [−0.60–1.38]
Calphostine C (0.1 μM)	9	0.26 ± 0.04^a	0.24 ± 0.19	−0.01 ± 0.20	−0.04 [−0.80–0.88]
SB203580 (0.1 μM)	10	0.37 ± 0.07^a	0.36 ± 0.10	−0.01 ± 0.13	−0.04 [−0.91–0.84]
Y27632 (1 μM)	11	0.37 ± 0.08^a	0.37 ± 0.16^b	−0.01 ± 0.16	−0.12 [−0.95–0.72]

Δ (−log EC₅₀) represented the change in potency between the pre-stretch and the post-stretch concentration-response curves to ACh (Fig. 1). Values are means ± standard error of the mean and standardized effect size |d| and its 95% confidence interval [CI] for the difference between means. The observed effect of pretreatment is small (IdI ≥ 0.20), medium (IdI ≥ 0.50), or large (IdI ≥ 0.80) according to the Cohen’s conventions [23]. The 95% CI for d consists of the uncertainty around the real effect of pretreatment. ^a P < 0.001, ^b P < 0.05, ^c P < 0.01 stretched vs. paired non-stretched control bronchi. ^d P < 0.05 pretreatment vs. no pretreatment. ACh, acetylcholine

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