Hepatic adenine nucleotides and DNA synthesis during the regenerative and atrophic process of the liver lobes after selective portal vein ligation

Abstract

Selective portal vein occlusion prior to aggressive hepatic resection is now an alternative way to decrease postoperative morbidity and mortality rates. However, the detailed changes in the hepatic energy status and DNA synthesis rate in both portal vein ligated (PVL) and nonligated (PVNL) lobes of the liver are not clear. In rats, the portal branch that supplies 70% of the liver volume was ligated, and changes in arterial ketone body ratio (AKBR), liver weight, histology, DNA synthesis rate and adenine nucleotides of the PVL and PVNL liver lobes were determined before and 1, 2, 4 and 7 days after portal vein ligation, and compared with those in sham-operated rats. The weight of the PVL lobes decreased, while that of the PVNL lobes increased depending on time. The DNA synthesis rates of the PVNL lobes were significantly higher than those in sham-operated control liver during the first 4 days with the maximal value on the 2nd day, while those of PVL lobes were essentially similar to the control values. Energy charge (EC) in both PVL and PVNL lobes significantly decreased on day 1 and recovered gradually, but with less extent in the regenerating PVNL lobes. The concentrations of total adenine nucleotides (TAN) in both the PVL and PVNL lobes were essentially similar during the first 2 days, but became significantly lower in PVL lobes after day 4. A decrease in EC preceded an increase in DNA synthesis only in the PVNL lobes, in contrast to the PVL lobes. Mitosis of hepatocytes on day 2 and subsequently enlarged lobules with an increased number of hepatocytes were histologic features in the PVNL liver. The AKBR was not correlated with hepatic energy charge of the liver. In conclusion, PVNL liver regenerates preceded by a decrease in EC and a subsequent increase in DNA synthesis keeping TAN constant, while PVL liver becomes atrophic, with a similar change in EC of the PVNL liver but ultimately decreased TAN without any change in DNA synthesis. AKBR is not a parameter reflecting the hepatic EC after portal branch ligation.