Table 2.

The effect of testosterone depends on the order of its addition

Mode of testosterone addition	Concentration of testosterone
	1 pM	100 nM	1 μM	100 μM
	Relaxation (% of initial contraction)
Increasing concentrations	1.9±0.6	2.1±0.6	5.4±1.5	10.6±3.7
Random sequence	0.9±0.8	4.5±0.8*	1.4±0.7*	8.4±0.4

Relaxation of airway smooth muscle precontracted with 10 μM CCh after addition of testosterone in increasing concentrations or after addition of different concentrations of testosterone in a random sequence (100 μM, 100 nM, 1 pM, 1 μM). Values are presented as percentage of initial contraction.

Data are presented as mean values of 5 experiments±s.e.m.

Significant differences between groups at P<0.05 (^*), Mann–Whitney U unrelated samples test.