期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：1981
卷号：27
期号：2
页码：149-163
DOI：10.3177/jnsv.27.149
出版社：Center for Academic Publications Japan
摘要：To elucidate the response of amino acid metabolism in the liver to dietary protein and plasma amino acids, the livers of adult rats fed on diet containing 10% (control) or 3% (low-protein) egg protein for 3 weeks were perfused for 120 min with amino acid-free medium in Experiment 1 or medium containing an amino acid mixture simulating that in plasma in Experiment 2. During perfusion about 40% of the free amino acids were lost from the liver in Exp. 1, and about 30% in Exp. 2. During this period, in Exp. l the releases of free amino acids and urea into the medium were 140μmol and 2.52mg, respectively, in the control group and 207μmol and 1.10mg, respectively, in the low-protein group. Thus release was greater than decrease in free amino acids in the liver. Essential amino acids, particularly lysine and branched chain amino acids, were released preferentially. The results suggest that the amount of breakdown of liver protein in the two groups was similar, but that the nitrogen was mainly released as free amino acids in the low-protein group, and as urea in the control group. On the contrary, in Exp. 2 the amount of nitrogen released from the liver was comparable to the decrease in amino acids in the liver, and the releases of urea were also less, being 1.83 mg in the control group and 0.54mg in low-protein group. The results show that amino acid metabolism in the liver is greatly affected by the nutritional state of the animal and the amino acid content of the perfusion fluid.
关键词：liver pefusion;amino acid balance in liver;adult rats;egg protein;urea synthesis
