Table 5. Bronchodilator Effect of Same Compounds on Guinea Pig Trachea.

compd	mean activitya ± SEM	IC50 b (μM)	95% CL (×10-6)
16	77 ± 1.7c	1.11	0.87–1.23
17	67 ± 1.3	0.061	0.043–0.084
18	57 ± 2.4	0.13	0.10–0.17
19	33 ± 1.1
20	26 ± 2.1
21	38 ± 2.2
25	92 ± 1.4	2.34	1.89–2.89
26	40 ± 2.1
28	64 ± 1.6d	0.031	0.023–0.041
30	27 ± 1.3
31	87 ± 1.5c	3.66	1.21–4.74
37	47 ± 1.1
38	64 ± 2.5c	0.058	0.026–0.099
39	19 ± 0.7d
45	35 ± 2.2c
nifedipine	62 ± 2.3	0.096	0.070–0.13
48	30 ± 2.6
49	68 ± 2.2	0.00059	0.00042–0.00083
50	29 ± 1.7
genistein	14 ± 1.1

^aPercent inhibition of carbachol (1 μM) induced contraction on guinea pig trachea at 10^–5 M. The 10^–5 M concentration gave the maximum effect for most compounds.

^bCalculated from log concentration–response curves (Probit analysis by Litchfield and Wilcoxon¹⁷ with n = 6–7). When the maximum effect was <50%, the IC₅₀ values were not calculated.

^cAt 10^–4 M.

^dAt 10^–7 M.