Fig. 1. (A ) Mean arterial pressure (MAP), (B ) mean pulmonary arterial pressure (PAP), (C ) systemic vascular resistance (SVR), (D ) pulmonary vascular resistance (PVR), (E ) cardiac output, (F ) heart rate of awake lambs after an intravenous infusion of prewarmed (37°C) autologous whole blood (n = 7), after an intravenous infusion of PolyHeme (Northfield Laboratories, Evanston, IL) (1.08 g hemoglobin/kg body weight, n = 4), or after an intravenous infusion of PolyHeme (1.08 g hemoglobin/kg body weight, n = 4) in lambs that were pretreated with inhaled 80 ppm nitric oxide for 1 h followed by continuously breathing 5 ppm nitric oxide for 2 h (high/low inhaled nitric oxide [iNO], n = 4). *P < 0.05. PolyHeme value differs from whole blood and from PolyHeme + high/low iNO. **P < 0.05. Whole blood differs from PolyHeme + iNO.