The relationship between flow motion and tissue oxygenation was investigated during hemorrhage/retransfusion with and without dopamine in 14 pigs. During 45% bleed microvascular hemoglobin oxygen saturation (HBjO₂) and mucosal tissue oxygen tension (PO₂muc) were recorded in 7 control (C) and 7 dopamine treated animals (D). Mean arterial pressure and systemic oxygen delivery decreased during hemorrhage and returned to baseline after retransfusion. Hemorrhage decreased PO₂muc from 33±2.8 mmHg to 13±1.6 mmHg , HBjO₂ from 53±4.9% to 32±3.9% in C animals. During reperfusion PO₂muc and HBjO₂ remained low. Dopamine increased PO₂muc from 28±4.3 mmHg to 45±4.6 mmHg, HBjO₂ from 54±5.7% to 69±1.5% and attenuated the decrease in PO₂muc and HBjO₂ during hemorrhage. After retransfusion dopamine restored PO₂muc and HBjO₂ to baseline. C animals developed rhythmic HBjO₂ oscillations with increasing amplitude (frequency = 4.5 to 7.6 cpm) and showed inverse relationship between PO₂muc and HBjO₂ oscillation amplitude. Dopamine prevented regular flow motion. The association between decreased PO₂muc and increased oscillations in HbjO₂ after normalization of systemic hemodynamics and oxygen transport in control animals suggests a cause effect relationship between low tissue oxygen pressure and flowmotion activity within the jejunal microcirculation.