Effect of parenteral and enteral nutrition on hepatic albumin synthesis in rats

The route of nutrient delivery may alter the production of albumin and induce changes at the molecular level. Donryu rats (n = 75) were divided into the following three groups. The oral feeding (OR) group received a non-purified solid diet ad libitum, the parenteral nutrition (PN) group received a total parenteral nutrition (TPN) solution intravenously, and the enteral nutrition (EN) group received intragastric infusions of the TPN solution for 7 d. Serum albumin and glucocorticoid levels were measured and messenger RNA (mRNA) levels of albumin and hepatic specific transcription factors in the liver were analyzed. Serum albumin and albumin mRNA levels in the PN group became significantly decreased compared to those in the OR group, whereas the EN group did not show a significant difference compared to the OR group. mRNA levels of DBP, D-site binding transcription factor for the albumin gene, showed a circadian rhythm in the OR and EN groups, but not in the PN group, as indicated by a DBP mRNA level at 2200 h in the PN group that was significantly lower than that in the OR group. mRNA levels of C/EBP α, CCAAT-enhancer binding protein α, were highest in the OR group and lowest in the PN group. In contrast, mRNA levels of C/EBP β were highest in the PN group and lowest in the OR group. Serum glucocorticoid level showed a circadian rhythm in the OR group, highest at 2200 h and lowest at 1000 h, whereas such a rhythm was not found in either the PN or the EN group. Albumin synthesis was down-regulated in PN in association with changes in transcription factors. A loss of circadian rhythm reflected in changes of DBP mRNA and serum glucocorticoid level may play a role. Down-regulation of albumin was improved by enteral feeding, indicating that EN is more advantageous for albumin synthesis than PN.