Hepatic venous hemoglobin oxygen saturation predicts regenerative status of remnant liver after partial hepatectomy in rats

This study was designed to evaluate the use of hepatic venous hemoglobin oxygen saturation (Shvo(2)) as an indicator of hepatic oxygen supply-demand relation and also regenerative status of the liver after partial hepatectomy in rats. We assessed the Shvo(2) levels for 7 days, as well as hepatic hemodynamics, oxygen consumption, DNA synthesis and energy charge of the remnant liver for 3 days after 50% hepatectomy or sham operation. Total hepatic oxygen consumption (HVo(2)) per liver weight, hepatic oxygen extraction ratio (Ho2ER), and DNA synthesis were significantly elevated at days 1 and 3 after hepatectomy, compared with the preoperative levels. Meanwhile, significantly decreased Shvo(2) levels were observed at days 1 and 3, and the Shvo(2) levels were significantly correlated with the HVo(2). Furthermore, the decreased Shvo(2) levels were synchronized with the increased DNA synthesis in the remnant liver. Energy charge levels were also significantly decreased at day 1 after hepatectomy. These results suggest that the regenerating liver demands an increased amount of oxygen for mitochondrial oxidative phosphorylation to restore hepatic energy charge. In conclusion, the Shvo(2) after hepatectomy may reflect oxygen metabolic status in the remnant liver and could be useful for estimating liver regeneration.