MK-5046 increases MAP and heart rate. The MAP (A–C) and heart rate (D–F) response to MK-5046 (3 mg/kg ip) or vehicle (saline) was studied in conscious wild-type (WT) and Brs3−/y (KO) mice at 16–17 wk of age. Data are change from the baseline, 120 to 1 min before treatment. C and F: mean change in MAP and heart rate at 61–120 min postinjection. Baseline MAPs were 98 ± 1 (WT/Veh), 97 ± 2 (WT/MK-5046), 102 ± 2 (KO/Veh), and 102 ± 2 (KO/MK-5046) mmHg. Baseline heart rates were 526 ± 16 (WT/Veh), 513 ± 16 (WT/MK-5046), 482 ± 15 (KO/Veh), and 490 ± 15 (KO/MK-5046) beats/min. Data are means ± SE; n = 5–6/group. *P < 0.05 vs. vehicle.