Energy substrate for liver regeneration after partial hepatectomy in rats: effects of glucose vs fat

This study evaluated the effects of glucose or fat on liver regeneration after partial hepatectomy in rats. Partial hepatectomy with resection of the median and left lateral lobes (67.31%) was performed on three rat groups. Two groups were infused with high-glucose (HG) or high-fat (HF) solutions intravenously 2 days before surgery. The control (C) group was allowed to eat instead of receiving intravenous infusions. Another group with sham operation only was also allowed to eat. Rats were killed 6, 24, 48, or 72 hours after the operation. Remnant liver weight, DNA synthetic rate, DNA content, and mitotic index were chosen as comparing indicators. Blood glucose, serum free fatty acid (FFA), total ketone bodies, and ketone body ratio were measured. Transmission electron microscopy was also used to observe the remnant liver. The results showed that the HG rat group had a better regenerative condition than did the HF rat group (p less than .01). Glucose is the predominant energy substrate when enough is offered during the immediate posthepatectomy phase. FFA utilization occurred only very early after partial hepatectomy, and it was remarkable in the control group, moderate in the HF group, and low in the HG group. Shifting of the energy substrate to FFA occurred only when glucose was not available for utilization. The disappearance and reappearance of glycogen, and accumulation of fat in cytoplasm as shown by transmission electron microscope pictures support this conclusion.