Figure 5.

Effect of Selective β₁- and β₂-Adrenoceptor Antagonists on Prop-BY630 Binding to MDA-MB-231^HM Cells In Vivo

Drug-receptor engagement in the primary tumor region was investigated using 0.1 mg/kg (IT) Prop-BY630 in mice treated with the β₂-selective antagonist ICI 118551 or the β₁-selective antagonist CGP20712A. At 45 min before fluorescent ligand injection, mice were administered (IV) with either PBS (100 μL), CGP201712A (100 μL; 10 mg/kg in PBS), or ICI 118551 (100 μL; 1 mg/kg in PBS). Data represent mean ± SE of 6 mice in each group. Measurements were made 1 hr after administration of Prop-BY630. Baseline measurements were obtained on the previous day in each mouse when furimazine was administered via the tail vein, but Prop-BY630 was not injected into the tumor. *p < 0.05 or ^#p < 0.001 with respect to the baseline (t = 0) signal in each group. *p < 0.05 versus control Prop-BY630 binding (1 hr PBS). One-way ANOVA with Tukey's posthoc tests.