Figure 4.

Effects of BMY7378 or bunazosin on blood pressure responses in α_1D^+/+ and α_1D^–/– mice under anesthesia. Inhibitory effects of BMY7378 or bunazosin on the pressor response to norepinephrine in α_1D^+/+ (upper) and α_1D^–/– (lower) mice. β-Blocker, propranolol (1 mg/kg) was preadministered, and BMY7378 (100 μg/kg) or bunazosin (10 μg/kg) was injected into male α_1D^+/+ or α_1D^–/– mice (10–12 weeks old) 10 minutes prior to continuous infusion of norepinephrine (1 μg/kg/min, for 10 minutes). Points represent the mean ± SEM of eight mice. Open squares, norepinephrine infusion; open circles, norepinephrine infusion + BMY7378 pretreatment; filled circles, norepinephrine infusion + bunazosin pretreatment. *P < 0.05 as compared with norepinephrine infusion.