EFFECT OF CARBOHYDRATES ON AMMONIUM AND KETOACID EXCRETION DURING STARVATION
EFFECT OF CARBOHYDRATES ON AMMONIUM AND KETOACID EXCRETION DURING STARVATION
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DOI：
10.1172/jci107016
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发表时间：
1972-01-01
影响因子：
15.9
通讯作者：
GINSBERG, R
中科院分区：
文献类型：
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作者：
SAPIR, DG;WALKER, WG;GINSBERG, R
研究人员对九名肥胖受试者在长期饥饿期间口服微量碳水化合物的代谢影响进行了研究。测量是在完全饥饿的对照期间、每天摄入 7.5 克碳水化合物期间、最后每天摄入 15.0 克碳水化合物期间进行的。摄入碳水化合物后每日酮酸排泄量下降，并与碳水化合物摄入量显着相关（r=0.62，P<0.01）。尽管酮酸下降，但血液酮酸、血浆游离脂肪酸和血清胰岛素的浓度在整个研究过程中保持恒定。与酮酸输出密切相关的尿铵排泄量（r=0.95，P<0.001）在碳水化合物摄入后也显着下降。细胞外或尿液pH值没有显着变化。当尿铵排出量下降时，尿素氮排泄量没有变化。这些结果表明：饥饿者体内酮酸和铵的排泄对微量摄入的碳水化合物极其敏感；酮尿的变化似乎是由于摄入碳水化合物后肾脏酮酸重吸收增加所致；饥饿时减少肾氨输出的氮节约效应可以与由于尿液尿素排泄变化而发生的氮节约分开。
The metabolic effects of oral ingestion of minute quantities of carbohydrate during prolonged starvation were studied in nine obese subjects. Measurements were made during a control period of total starvation, during the ingestion of 7.5 g carbohydrate daily, and finally during the ingestion of 15.0 g carbohydrate daily. Daily ketoacid excretion fell after carbohydrate ingestion and was significantly correlated (r= 0.62,P< 0.01) with the amount of carbohydrate administered. Despite this fall in ketoacids, the concentration of blood ketoacids, plasma free fatty acids, and serum insulin remained constant throughout the study. Urinary ammonium excretion, closely correlated with ketoacid output (r= 0.95,P< 0.001), also fell significantly after carbohydrate ingestion. No significant changes were present in extracellular or urinary pH. Urea nitrogen excretion did not change when urinary ammonium output fell. These results indicate that: the excretion of ketoacids and ammonium in starving man is exquisitely sensitive to minute amounts of ingested carbohydrate; the change in ketonuria appears to be due to increased renal ketoacid reabsorption after carbohydrate ingestion; and the nitrogen-sparing effect of reducing renal ammonium output in starvation can be dissociated from nitrogen sparing occurring because of changes in urine urea excretion.