PLASMA ARGININE KINETICS IN ADULT MAN - RESPONSE TO AN ARGININE-FREE DIET
PLASMA ARGININE KINETICS IN ADULT MAN - RESPONSE TO AN ARGININE-FREE DIET
复制标题
DOI：
10.1016/0026-0495(94)90166-x
复制
发表时间：
1994-01-01
影响因子：
9.8
通讯作者：
YOUNG, VR
中科院分区：
文献类型：
--
作者：
CASTILLO, L;AJAMI, A;YOUNG, VR
为了探索全身精氨酸代谢对精氨酸摄入量变化的反应，对八名健康成年男性的血浆精氨酸动力学进行了研究，这些男性接受富含精氨酸或不含精氨酸的无氨基酸饮食，持续 6 天，然后在第 7 天进行示踪剂研究。示踪剂方案持续 8 小时。在最初的 3 小时内，受试者保持在吸收后（禁食）状态，在接下来的 5 小时内，他们每隔 30 分钟吃少量的食物。给予1-[胍基-13C]精氨酸、1-[5,5,5-2H3]亮氨酸和[15N2]尿素预连续静脉输注以估计血浆氨基酸通量和尿素产生率。在禁食和进食状态下，富含精氨酸饮食的血浆精氨酸通量（μmol·kg−1·h−1，平均值±SD）分别为69±8和87±12（P<.01），无精氨酸饮食分别为63±14和51±7（P<.01，来自富含精氨酸）。与富含精氨酸的结果相比，在无精氨酸饮食期间，餐后血浆精氨酸和鸟氨酸浓度降低（P<.01），瓜氨酸浓度升高（P<.01）。饮食组之间的亮氨酸通量和尿素生成率没有差异。与富含精氨酸饮食的受试者相比，接受无精氨酸饮食的受试者的餐后状态精氨酸通量较低，这似乎完全是由于前一组中精氨酸从肠道进入的速率降低。从这些结果中，我们得出结论，精氨酸的从头合成率平均约为 16 μmol·kg−1·h−1，在 6 至 7 天内不受无精氨酸饮食的影响。
To explore the response of whole-body arginine metabolism to a change in arginine intake, plasma arginine kinetics were investigated in eight healthy adult men who received anl-amino acid diet supplying an Arg-rich or Arg-free intake for 6 days before undergoing a tracer study on day 7. The tracer protocol lasted for 8 hours. For the first 3 hours subjects remained in the postabsorptive (fasted) state, and during the following 5 hours they consumed small meals at 30-minute intervals. Primed continuous intravenous infusions ofl-[guanidino-13C]arginine,l-[5,5,5-2H3]leucine, and [15N2]urea were administered to estimate plasma amino acid fluxes and the rate of urea production. For the fasted and fed states, plasma arginine fluxes (μmol · kg−1· h−1, mean ± SD) were 69 ± 8 and 87 ± 12 (P< .01), respectively, for the Arg-rich diet and 63 ± 14 and 51 ± 7 (P< .01, from Arg-rich) for the Arg-free diet. Compared with the Arg-rich results, fed-state plasma arginine and ornithine concentrations were decreased (P< .01) and citrulline concentration was increased (P< .01) during the Arg-free diet period. Leucine fluxes and rates of urea production did not differ between the diet groups. The lower fed-state arginine flux in subjects receiving the Arg-free compared with the Arg-rich diet appears to be entirely due to the decreased rate of entry of arginine from the intestine in the former group. From these results, we conclude that the de novo rate of arginine synthesis, with a mean of about 16 μmol · kg−1· h−1, is not affected by an Arg-free diet for 6 to 7 days.