Systemic hemodynamics measured throughout the study. HR (A) and MAP (B) measured at baseline, after administration of saline, apoHb, or apoHb-Hp, and after 20% isovolemic exchange transfusion of PolyHb. Top panels show the measured values; bottom panels show values normalized to the baseline of the same animal. Gray lines connect measurements obtained in the same animal. *P < .05 compared between groups. ^aP < .05 compared with the saline administration group at the same time point. ^bP < .05 compared with apoHb administration group at the same time point. n = 5 animals per group.