Figure 2.

Stimulation of [³⁵S]GTPγS binding by mianserin and mirtazapine in CHO cells. (A) Membranes of CHO cells untransfected (CHO/K1) or stably transfected with the different opioid receptor subtypes were incubated with 1.0 nM [³⁵S]GTPγS in the presence of the indicated concentrations of mianserin (mians). Values are the mean ± SEM of three experiments. (B) Stimulation of [³⁵S]GTPγS binding by mianserin, mirtazapine (mirtaz) and the full κ receptor agonist (–)-U-50 488 in CHO/KOP membranes. Values are the mean ± SEM of three to five experiments. (C) Antagonism of [³⁵S]GTPγS binding stimulation by the κ receptor antagonist nor-BNI. CHO/KOP cell membranes were incubated with either vehicle, 100 nM (–)-U50,488, 30 µM mianserin or 50 µM mirtazapine in the presence of either vehicle or 100 nM nor-BNI. Values are the mean ± SEM of three experiments. ***P < 0.001 significantly different from control (vehicle + vehicle) by anova. (D) Concentration-dependent-inhibition of mianserin-stimulated [³⁵S]GTPγS binding by nor-BNI. CHO/KOP cell membranes were incubated with either vehicle or 30 µM mianserin in the presence of the indicated concentrations of nor-BNI. Values are the mean ± SEM of three experiments.