Interorgan relationships of alanine and glutamine during fasting in the conscious dog.
Interorgan relationships of alanine and glutamine during fasting in the conscious dog.
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清醒狗禁食期间丙氨酸和谷氨酰胺的器官间关系。
DOI：
10.1016/0022-4804(83)90006-9
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Abumrad,NN
中科院分区：
文献类型：
--
作者：
Miller,BM;Cersosimo,E;McRae,J;Williams,PE;Lacy,WW;Abumrad,NN
本研究旨在评估清醒、禁食过夜的狗体内谷氨酰胺和丙氨酸的器官间关系，并确定渐进性禁食所发生的变化。在研究之前，狗禁食 18 小时（n= 6）、48 小时（n= 6）和 96 小时（n= 6）。先前已将导管植入股动脉、肾静脉、门静脉和肝静脉中，并在3小时的实验期间以30分钟的间隔用于采血。肝血流量和肾血流量分别通过吲哚菁绿和对氨基马尿酸（PAH）提取方法测定。通过将适当的动静脉浓度差乘以血流量来估计平衡数据（微摩尔/千克/分钟）。禁食 48 小时后，肝脏对谷氨酰胺的吸收减少了 50%，到 96 小时，肝脏成为谷氨酰胺的净生产者。在禁食期间肠道利用率保持恒定。肾脏的利用率随着禁食而逐渐增加。肝脏提取的丙氨酸随着禁食而下降，在 96 小时时下降至原始摄取量的 40%。禁食的前 48 小时内，肠道产生的丙氨酸下降，但此后保持稳定。在整个饥饿期间，肾脏产生的丙氨酸增加。禁食后，动脉中谷氨酰胺的浓度会上升，而丙氨酸的浓度即使禁食 48 小时也会下降。肝脏通过成为谷氨酰胺的净生产者，而肾脏通过增加其丙氨酸的生产，减少了对这两种氨基酸的外周释放的需求，因此在禁食期间可能具有节省蛋白质的作用。
This study was designed to assess the interorgan relationships of glutamine and alanine in the conscious, overnight fasted dog, and to determine changes which occur with progressive fasting. Dogs were fasted for 18 hr (n= 6), 48 hr (n= 6), and 96 hr (n= 6) prior to the study. Catheters had been previously implanted in the femoral artery, renal vein, portal vein, and hepatic vein, and were used for blood sampling at 30-min intervals during the 3-hr experimental period. Hepatic and renal blood flows were determined by indocyanine green andpara-aminohippuric acid (PAH) extraction methods, respectively. Balance data (micromoles/kilogram/minute) were estimated by multiplying the appropriate arteriovenous concentration differences by blood flows. Hepatic uptake of glutamine decreased 50% after a 48-hr fast, and by 96 hr, the liver became a net producer of glutamine. Gut utilization remained constant throughout fasting. The kidney's utilization gradually increased with fasting. The hepatic extraction of alanine fell with fasting, declining to 40% of its original uptake at 96 hr. The gut's production of alanine fell during the first 48 hr of fasting, but remained stable thereafter. The kidney's production of alanine increased throughout the period of starvation. The arterial concentration of glutamine rose with fasting, while that of alanine fell even with a 48 hr fast. The liver, by becoming a net producer of glutamine, and the kidney, by increasing its production of alanine, decrease demands for peripheral release of these two amino acids, and thus may have protein-sparing actions during fasting.