Effect of non-essential amino acid glycine administration on the liver regeneration of partially hepatectomized rats with hepatic ischemia/reperfusion injury

Summary Background & aims Liver regeneration after partial hepatectomy or transplantation is a critical problem to affect prognosis. Ischemia/reperfusion (I/R) is an unavoidable process during liver resection or transplantation. The aim of this study was to investigate the effect of glycine on the regeneration of the remnant liver with I/R injury after partial hepatectomy. Methods Partially hepatectomized rat with liver I/R injury was prepared by a two-thirds partial hepatectomy following 30 min of total hepatic ischemia. Glycine (5% in water) was orally administered to rats for 3 days as drinking water before the surgery. Results Mortality rate in partially hepatectomized rats with severe hepatic I/R injury was so high compared to that in the rats with partial hepatectomy alone. However, when glycine was given to the partially hepatectomized rats with hepatic I/R injury, the survival rate, the recovery rate of the remnant liver weight, and the liver injury were obviously improved. On the other hand, when glycine-treated rats underwent partial hepatectomy without hepatic I/R, the recovery rate of the remnant liver weight was decreased as compared with that of the rats with partial hepatectomy alone. In these settings, glycine administration prevented the elevation of serum TNF-α levels and liver TNF-α mRNA expression. Conclusions Glycine improved the regeneration of the remnant liver with severe I/R injury after partial hepatectomy. This improvement may be at least partly due to the amelioration of the hepatic I/R injury by glycine. Glycine seems to be clinically beneficial to the prognosis of patients with liver resection.