Objective: To describe systemic and mesenteric hemodynamics, metabolism, and intestinal tonometry in a rat model of supraceliac aortic cross-clamping and declamping. Design: Prospective, randomized, experimental study. Setting: University cardiovascular research laboratory. Participants: Twelve male anesthetized and ventilated Sprague-Dawley rats. Intervention: Supraceliac aortic cross-clamping was performed for 30 minutes, followed by declamping and reperfusion for 180 minutes or sham clamping and sham declamping. Measurements and Main Results: Z Mean arterial blood pressure; abdominal aortic, superior mesenteric, and carotid artery blood flow; intestinal mucosal tonometry; hemoglobin; lactate; and blood gases were measured before and after 30 minutes of aortic cross-clamping and 15, 30, 60, 120, and 180 minutes after declamping during reperfusion, Aortic cross-clamping induced an increase in mean arterial pressure (117 ± 20 mmHg to 147 ± 12 mmHg), an increase in right atrial hemoglobin saturation (66% ± 11% to 81% ± 6%), an increase in lactate levels (1.7 ± 0.7 mmol/L to 4.3 ± 1.3 mmol/L), and an increase in tonometric PCO 2 (49.6 ± 5.0 mmHg to 75.6 ± 8.6 mmHg). Three hours of reperfusion after declamping resulted in significantly decreased mean arterial pressure (38 ± 10 mmHg); decreased aortic (101 ± 12 mL/min/kg to 57 ± 32 mL/min/kg), mesenteric (19 ± 4 to 13 ± 6 mL/min/kg), and carotid (12 ± 4 mL/min/kg to 5 ± 3 mL/min/kg) blood flows; and elevated lactate levels (4.2 ± 2.0 mmol/L). Tonometric PCO 2 had normalized to baseline levels (51.9 ± 3.8 mmHg), but PCO 2 gap was significantly higher than in sham clamped rats (17.9 ± 7.8 mmHg v 7.0 ± 2.6 mmHg). Conclusions: Hemodynamic and metabolic effects of aortic cross-clamping and declamping known from large animal models are reproducible using a rat model. Intestinal tonometry indicated mesenteric ischemia during aortic cross-clamping, which was reversible to preclamp values within 30 minutes of reperfusion after declamping.