Vidnes J
Scand J Clin Lab Invest. 1976 Jul;36(4):347-56. doi: 10.1080/00365517609055270.
The in vivo gluconeogenesis from alanine and glycerol in infants and children was studied by an isotope method, using 14C-labeled substates with subsequent separation of the radioactive compounds by thin-layer chromatography. Seven patients, aged 2 months to 2 years 11 months, with normal carbohydrate metabolism were studied. Trace amounts of [14C]alanine were injected intravenously in four fasting patients. The 14C moved quickly from alanine to lactate, with a peak activity in lactate obtained before 5 min. From 10 min on, the label disappeared rapidly from both. An equilibrium was established between alanine and lactate, displaced towards lactate. The peak activity in glucose was reached in 10-20 min, amounting to 10% of total injected activity. In one patient, who was also studied after a meal, the disappearance rate of alanine was reduced by 50%. Despite this reduction the appearance of label in lactate was increased, whereas the amount of label in glucose was much reduced. [14C]glycerol was injected intravenously in three fasting patients. In one patient, who received only a tracer dose of glycerol, 5 times more 14C appeared in glucose than in the patients studied with [14C]alanine. In two patients receiving a glycerol load together with the [14C]glycerol, the disappearance rate of glycerol was markedly reduced, as was the conversion of carbon to glucose and lactate.
采用同位素方法，使用14C标记的底物，随后通过薄层色谱法分离放射性化合物，研究了婴幼儿体内丙氨酸和甘油的糖异生作用。对7名年龄在2个月至2岁11个月、碳水化合物代谢正常的患者进行了研究。对4名空腹患者静脉注射微量的[14C]丙氨酸。14C迅速从丙氨酸转移至乳酸，在5分钟前乳酸中出现峰值活性。从10分钟起，两者中的标记物迅速消失。丙氨酸和乳酸之间建立了平衡，且向乳酸方向偏移。葡萄糖中的峰值活性在10 - 20分钟时达到，占总注射活性的10%。在一名进食后也进行了研究的患者中，丙氨酸的消失率降低了50%。尽管有这种降低，乳酸中标记物的出现却增加了，而葡萄糖中标记物的量则大幅减少。对3名空腹患者静脉注射[14C]甘油。在一名仅接受微量甘油剂量的患者中，葡萄糖中出现的14C是用[14C]丙氨酸研究的患者的5倍。在两名同时接受甘油负荷和[14C]甘油的患者中，甘油的消失率显著降低，碳向葡萄糖和乳酸的转化也降低了。
