Urea formation by postoperative liver

The effect of liver left lobe resection (LR, 15–20% of the organ weight) on hepatic urea formation was investigated in 84 albino rats. The objects used for analysis of urea content included: operated left lobe (LLL), non-operated middle (MLL) lobe of the liver, blood (aorta, v. hepatica, v. porta), and choledochal bile. Arginase activity was examined in liver homogenate. On the day 3 and day 7 after resection reduced arginase activity was detected. LR caused a decrease in urea content in v. hepatica, but increased urea content in the arterial blood and v. porta. The increase in bile urea on day 7 was then changed for its decrease observed on day 14 of the postoperative period. The urea content in the liver on day 3 after LR was below the norm, while on days 7 and 14 it became normal. Results of this study suggest impaired urea formation by hepatocytes of the operated liver and activation of extrahepatic mechanisms of urea formation from arginine.