Fig. 5
Changes induced by various concentrations of noradrenaline in [35S]GTPγS binding in the presence of the subtype-selective α2A-adrenergic receptor antagonist BRL 44408 (a), the α2B/C-adrenergic receptor antagonist ARC 239 (b), the α2C-adrenergic receptor antagonist spiroxatrine (c) and the spiroxatrine + BRL 44408 combination (d) following pretreatment with progesterone. In all cases, the β-adrenergic receptors and the α1-adrenergic receptors were inhibited by propranolol and doxazosin. Basal refers to the level of [35S]GTPγS binding without substance. The statistical analyses were carried out with the ANOVA Dunnett test. **p < 0.01; ***p < 0.001