Figure 2.

Pressor response to vasoconstrictor agents in the α₁-adrenoceptor triple KO mouse (α₁-AR triple-KO). Drugs were intravenously injected through the jugular vein, and the mean arterial pressure (MAP) was monitored as described in the Methods section. (a and b) The changes in MAP (a) and HR (b) in response to phenylephrine are shown. The in vivo response of the MAP to a bolus injection of phenylephrine was not seen in α₁-AR triple-KO mice. (c and d) Systolic BP and HR of conscious mice. ^*P<0.05, ^**P<0.01, ^***P<0.001 vs WT mice. α₁-AR triple-KO, α₁-adrenoceptor triple KO; BP, blood pressure; HR, heart rate; KO. knockout; MAP, mean arterial pressure.