Utilization of alpha-ketoisocaproate for synthesis of hepatic export proteins and peripheral proteins in normal and cirrhotic subjects.
Utilization of alpha-ketoisocaproate for synthesis of hepatic export proteins and peripheral proteins in normal and cirrhotic subjects.
复制标题
利用α-酮异己酸合成正常和肝硬化受试者的肝输出蛋白和外周蛋白。
DOI：
10.1016/0016-5085(86)90250-7
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发表时间：
1986
期刊：
影响因子：
29.4
通讯作者：
Walser,M
中科院分区：
文献类型：
--
作者：
Muñoz,S;Walser,M
本文测定了7例正常人和5例肝硬变患者血浆纤维蛋白原、白蛋白、免疫球蛋白G、红细胞球蛋白和唾液粘蛋白中亮氨酸的比值，定义为(~(14)C剂量的百分比)/(~(3H)剂量的百分比)。用~(14)C标记的α-异己酮酯和~(3+)标记的亮氨酸连续灌胃。在大鼠实验中，全身蛋白质的比率已被证明是衡量KIC相对于亮氨酸的营养效率的指标。正常受试者Rin白蛋白和纤维蛋白原在3h后趋于稳定(0.63±0.05)，且彼此间无明显差别。免疫球蛋白中的比值R相似且恒定。血浆亮氨酸比值(0.62±0.06)显著低于粘蛋白(0.86±0.04)和球蛋白(0.73±0.04)，表明后者的亮氨酸主要来源于KIC局部转氨酶，而不是循环亮氨酸。结果5例肝硬变患者除Rin、Ig G和珠蛋白显著升高外，其余指标均无明显变化。因此，相对于亮氨酸，肝硬变不会改变口服KIC用于肝脏合成输出蛋白质的效率，但会增加其用于外周合成某些蛋白质的效率。
The ratioR, defined as (percent of dose of14C)/(percent of dose of3H) in the leucine of plasma fibrinogen, albumin, immunoglobulin G (IgG), red cell globin, and salivary mucin, was measured in 7 normal adults and in 5 cirrhotic patients during continuous intragastric infusion of 1-14C-labeled α-ketoisocaproate (KIC) and3H-labeled leucine. The ratioRmeasured in whole body protein has been shown in rat experiments to be a measure of the nutritional efficiency of KIC relative to leucine. In normal subjects,Rin albumin and fibrinogen became constant (0.63 ± 0.05) after the third hour and were indistinguishable from one another. The ratio R in IgG was similar and constant. The ratioRin plasma leucine (0.62 ± 0.06) was significantly lower than R in mucin (0.86 ± 0.04) or globin (0.73 ± 0.04), indicating that these latter proteins derive a significant fraction of their leucine from KIC transaminated locally, rather than from circulating leucine. Results in 5 cirrhotic patients were the same, except thatRin IgG andRin globin were significantly increased. Thus, cirrhosis does not alter the efficiency, relative to leucine, with which oral KIC is used for synthesis of export proteins by the liver, but increases the efficiency with which it is used for the synthesis of some proteins peripherally.