Table 3.

The effects of the selective CB₁ and CB₂ receptor antagonists SR141716 and SR144528 on basal tone, contraction in response to exogenous ACh and EFS-induced contraction

	SR141716 10 μM			SR144528 10 μM
	Effect	n	P	Effect	n	P
Change in basal tone (g)	0.08 ± 0.06	6	0.14	0.6 ± 0.2	6	0.052
Mean change of pEC50 in concentration–response curves for exogenous ACh	0.09	5	0.73	0.09	5	0.67
Maximum change in EFS-induced contraction (% vs. control)	13 ± 5	6	0.25	10 ± 5	6	0.10

For the effect on basal tone, tension was measured in bronchial rings before and after exposure to 10 μM of each antagonist; the difference in tension was analysed in a paired t-test. For the effect on exogenous ACh, a concentration–response curve for ACh was obtained before and after a 30 min incubation with vehicle or 10 μM of agonist; the response was modelled with non-linear regression and the E_max and pEC₅₀ of the second concentration–response curves with vehicle or agonist were compared with extra sum-of-squares F-test. For the effect on EFS-induced contraction, bronchial rings from the same patients were subjected to EFS either with vehicle only or with 10 μM of each antagonist, the difference between contraction in the control condition and contraction with the antagonist was calculated for each time point. Only the time point with the greatest difference is presented in the table. For EFS-induced contraction, statistical analysis was performed with a two-way, repeated-measures anova, followed by a Tukey–Kramer multiple comparison test.