Emori T, Sugiyama K, Nagase S
J Biochem. 1983 Sep;94(3):623-32. doi: 10.1093/oxfordjournals.jbchem.a134402.
Studies were made on tryptophan metabolism in Nagase analbuminemic rats (NAR), a mutant strain established from Sprague-Dawley rats that is characterized by lack of plasma albumin and hyperlipidemia. The total tryptophan concentration in NAR plasma is one fifth of normal, but the plasma free tryptophan concentration and liver and brain tryptophan levels are normal. Radioimmunoelectrophoresis showed that the tryptophan binding protein in NAR plasma is alpha 2-macroglobulin. The effect of oral tryptophan loading on plasma tryptophan and urinary excretion of tryptophan and its metabolites were examined. Differences between the values for NAR and normal rats were not significant except that the disappearance rate of tryptophan from NAR plasma was faster than in normal rats. The effects of several drugs that influence the concentration of non-esterified fatty acid (NEFA) or amino acids in the plasma of normal rats on NAR plasma tryptophan and NEFA concentrations and brain tryptophan metabolism were investigated. These drugs did not alter plasma NEFA and free tryptophan in NAR in the same direction as in normal rats. This difference may be caused by the difference of tryptophan binding proteins in the plasma of these two strains.
对长濑无白蛋白血症大鼠（NAR）的色氨酸代谢进行了研究，NAR是一种从斯普拉格-道利大鼠培育出的突变品系，其特征为缺乏血浆白蛋白和高脂血症。NAR血浆中的总色氨酸浓度为正常水平的五分之一，但血浆游离色氨酸浓度以及肝脏和大脑中的色氨酸水平正常。放射免疫电泳显示，NAR血浆中的色氨酸结合蛋白是α2-巨球蛋白。研究了口服色氨酸负荷对血浆色氨酸以及色氨酸及其代谢产物尿排泄的影响。除了NAR血浆中色氨酸的消失速率比正常大鼠快之外，NAR与正常大鼠的值之间的差异并不显著。研究了几种影响正常大鼠血浆中非酯化脂肪酸（NEFA）或氨基酸浓度的药物对NAR血浆色氨酸和NEFA浓度以及大脑色氨酸代谢的影响。这些药物在NAR中不会像在正常大鼠中那样使血浆NEFA和游离色氨酸发生同向改变。这种差异可能是由这两个品系血浆中色氨酸结合蛋白的差异所导致的。
