Ogata E S, Holliday M A
Biol Neonate. 1976;29(3-4):247-56. doi: 10.1159/000240870.
We determined the effects of feeding, starvation, and glucose infusion after starvation in newborn guinea pigs. We determined the rate of 14C-leucine incorporation into skeletal muscle (KS) as a measure of muscle protein synthesis and the rate of excretion of 3-methylhistidine as a measure of muscle myofibrillar protein catabolism (Kc). Fed newborns, who were in positive nitrogen balance, had the highest Ks and lowest Kc, while starved newborns had the lowest Ks and highest Kc. Infusing glucose after starvation decreased net protein catabolism and Kc, but did not increase Ks. The magnitude of change of Kc in response to starvation and glucose infusion was much greater than Ks. Changes in catabolic rate may influence net muscle protein balance to a greater degree than changes in synthetic rate.
我们测定了新生豚鼠喂食、饥饿以及饥饿后输注葡萄糖的影响。我们测定了¹⁴C-亮氨酸掺入骨骼肌（KS）的速率，以此作为肌肉蛋白质合成的指标，以及3-甲基组氨酸的排泄速率，以此作为肌肉肌原纤维蛋白分解代谢（Kc）的指标。处于正氮平衡的喂食新生豚鼠具有最高的Ks和最低的Kc，而饥饿的新生豚鼠具有最低的Ks和最高的Kc。饥饿后输注葡萄糖降低了净蛋白质分解代谢和Kc，但并未增加Ks。Kc对饥饿和葡萄糖输注的反应变化幅度远大于Ks。分解代谢率的变化可能比合成率的变化对净肌肉蛋白质平衡的影响更大。
