Quantitative role of splanchnic region in leucine metabolism: L-[1-13C,15N]leucine and substrate balance studies.
Quantitative role of splanchnic region in leucine metabolism: L-[1-13C,15N]leucine and substrate balance studies.
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内脏区域在亮氨酸代谢中的定量作用：L-[1-13C,15N]亮氨酸和底物平衡研究。
DOI：
10.1152/ajpendo.1990.259.1.e36
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Young,VR
中科院分区：
文献类型：
--
作者：
Yu,YM;Wagner,DA;Tredget,EE;Walaszewski,JA;Burke,JF;Young,VR
在六只长期插管禁食的杂种狗和八只持续肠内喂养完全氨基酸溶液（0.24 g.kg-1.h-1）的狗中评估了内脏区域（Sp）在全身亮氨酸代谢中的作用。我们使用预先连续静脉输注L-[1-13C,15N]亮氨酸和L-[1-14C]亮氨酸，并测量肠道、肝脏和Sp的动静脉同位素和亮氨酸平衡。在禁食状态下，动脉亮氨酸供应的3.5%在Sp中被氧化，占全身亮氨酸氧化的13%，其中10%由肝脏氧化。饲喂氨基酸后 1) 全身水平的亮氨酸碳和氮通量以及氧化增加（P 小于 0.01）； 2) Sp和肝脏中发生的全身亮氨酸氧化百分比分别增加（P小于0.01）至41%和27%； 3) 输送至 Sp 的亮氨酸代谢利用率从 47% 降低至 35%（P 小于 0.01）； 4）肠道中亮氨酸的脱氨率增加（P小于0.05），Sp中α-酮异己酸的再胺化率增加（P小于0.05）。这些发现表明，在禁食条件下，Sp 只占全身亮氨酸氧化的一小部分，但在氨基酸喂养期间，它在全身亮氨酸氧化中起着重要的作用。肠道和肝脏在控制外周组织亮氨酸供应方面发挥着协同作用。
The role of the splanchnic region (Sp) in whole body leucine metabolism was assessed in six chronically catheterized fasting mongrel dogs and in eight dogs during constant enteral feeding of a complete amino acid solution (0.24 g.kg-1.h-1). We used primed continuous intravenous infusions of L-[1-13C,15N]leucine and L-[1-14C]leucine and measurements of arteriovenous isotope and leucine balance across the gut, liver, and Sp. In the fasted condition, 3.5% of arterial leucine supply was oxidized in the Sp, accounting for 13% of total body leucine oxidation, with 10% by liver. With amino acid feeding 1) leucine carbon and nitrogen fluxes and oxidation were increased (P less than 0.01) at the whole body level; 2) the percent of whole body leucine oxidation occurring in the Sp and liver increased (P less than 0.01) to 41 and 27%, respectively; 3) fractional metabolic utilization of leucine delivered to the Sp was reduced (P less than 0.01) from 47 to 35%; 4) the deamination rate of leucine in the gut was increased (P less than 0.05), along with an increased reamination rate of alpha-ketoisocaproic acid in the Sp (P less than 0.05). These findings reveal that the Sp accounts for a small fraction of whole body leucine oxidation during the fasting condition, but it plays a quantitatively important role in total body leucine oxidation during amino acid feeding; the gut and liver play cooperative roles in controlling leucine supply to peripheral tissues.