Influence of CO2 tension on hepatic hemodynamics during portal arterialization

We investigated the effect of portal arterialization (PA) on hepatic energy metabolism and hepatic hemodynamics. Portal perfusion flow rate with arterial blood was 25% of the preperfusion portal flow. During PA up to 120 min, hepatic energy metabolism was maintained from the aspects of ATP, energy charge, and arterial ketone body ratio. However, during this PA, carbon dioxide tension (25-35 mm Hg) in arterial blood was lower than that in normal portal vein blood and portal vein resistance (PVR) was significantly increased during perfusion compared with that at preperfusion. When carbon dioxide tension (50-63 mm Hg) in arterial blood was made equivalent to that in normal portal vein blood by controlling the respiratory conditions, PVR was not increased during PA up to 120 min. It was suggested that PCO2 in perfusion blood should change PVR, while it should not change hepatic energy metabolism when portal perfusion flow rate with arterial blood was 25% of the preperfusion portal flow.