Figure 1. Mean arterial pressure (MAP), heart rate, and cardiac index (CI) during sodium pentobarbital (PB) anesthesia. Bsln = baseline. Inf = PB infusion. All statistical comparisons were made against baseline in each group (anesthetized animals breathing spontaneously [PB-S] or ventilated with air [PB-V] and nonanesthetized animals [NaCl] receiving 0.9% sodium chloride) and between the PB-S and PB-V groups. *Significantly different from baseline (P < 0.05).