Fig. 6.

Changes from baseline MAP or HR following ICV infusions of the ACE substrate ANG I (275 ng/min). ANG I was given both before and after an ICV infusion of captopril (1.5 μg) as described in materials and methods. There was a 15-min gap between the end of the first ANG I infusion and the start of captopril infusion. Another 15-min recovery period ensued after captopril before the start of the second ANG I infusion. Baseline MAP and HR values were determined over the 10-min period immediately preceding each ANG I infusion and were subtracted from the absolute MAP and HR to calculate ΔMAP or ΔHR. Precaptopril baseline MAP: α₂ +/− = 113 ± 4, +/+ = 116 ± 3 mmHg; HR: α₂ +/− = 491 ± 17, +/+ = 457 ± 28 beats/min. Postcaptopril baseline MAP: α₂ +/− = 120 ± 4, +/+ = 118 ± 3 mmHg; HR: α₂ +/− = 502 ± 20, +/+ = 450 ± 25 beats/min.