Acute liver damage induced by the administration of carbon tetrachloride is characterized by lipid accumulation in the liver and changes in the plasma free amino acid profile. The major objective of the present study was to clarify the relationships between liver lipid levels and plasma free amino acids, and to estimate liver lipid contents via the concentrations of plasma free amino acids. Mice were administered with carbon tetrachloride or olive oil. Liver and plasma samples were obtained before (initial value) and after 1, 3 and 7 days of administration. Liver triacylglycerol increased at 1 day and total cholesterol was raised at 1 and 3 days post injection of carbon tetrachloride, and thereafter both returned to their initial values. L-Phenylalanine, L-serine and L-alanine were significantly increased, but L-arginine was significantly decreased at 1 day. Liver triacylglycerol and total cholesterol levels were linearly, but weakly, correlated with several amino acids. Thus, stepwise regression analysis was applied and we found that the liver triacylglycerol level could be estimated by the levels of free plasma L-histidine, L-methionine and L-phenylalnine, and that the liver total cholesterol could be estimated by the levels of L-glutamine, L-valine and L-phenylalnine. In conclusion, the increase in plasma free L-phenylalanine plays an important factor in the accumulation of liver lipid induced by acute treatment with carbon tetrachloride in mice.
Shinya Takagi, Daichi Oikawa, Hiromi Ikeda, Nozomi Tateiwa, Kazunori Koba, Vishwajit S. Chowdhury, Shinobu Yasuo, Mitsuhiro Furuse.