ADAPTATION TO PROLONGED STARVATION IN THE RAT - CURTAILMENT OF SKELETAL-MUSCLE PROTEOLYSIS
ADAPTATION TO PROLONGED STARVATION IN THE RAT - CURTAILMENT OF SKELETAL-MUSCLE PROTEOLYSIS
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DOI：
10.1152/ajpendo.1981.241.4.e321
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发表时间：
1981-01-01
影响因子：
--
通讯作者：
RUDERMAN, NB
中科院分区：
文献类型：
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作者：
GOODMAN, MN;MCELANEY, MA;RUDERMAN, NB
先前的研究已经确定，16周龄的非肥胖和肥胖大鼠在长期饥饿期间可以保存体内蛋白质。为了确定这一点的基础上，蛋白质的合成和降解骨骼肌中进行了评价，在这些大鼠的隔离灌注后躯，在进食状态下，当饥饿2，5，10和11天。以4周龄和8周龄大鼠为对照。结果表明，对饥饿的反应取决于几个因素：大鼠的年龄，肥胖程度和禁食的持续时间。饥饿的早期事件是肌肉蛋白质合成的下降。这发生在所有组中，尽管这种减少在老年大鼠中发生得更慢。饥饿后的反应是肌肉蛋白水解的增加。这发生在8周龄大鼠的2 - 5天之间。在16周龄的大鼠中，直到5-10天才发生，并且在此之前有一段时间的蛋白水解减少。在16周龄肥胖大鼠中，蛋白水解减少持续超过10天，在研究期间未观察到继发性增加。老年和肥胖大鼠在饥饿期间保存体内蛋白质的能力部分是由于肌肉蛋白水解的减少。这种适应似乎与脂质燃料的可用性相关。
Previous studies have established that 16-wk-old nonobese and obese rats conserve body protein during prolonged starvation. To determine the basis for this, protein synthesis and degradation in skeletal muscle were evaluated in the isolated perfused hindquarters of these rats, in the fed state and when starved for 2, 5, 10 and 11 days. Rats aged 4 and 8 wk were used as a comparison. The results indicate that the response to starvation depends on several factors: the age of the rat, its degree of adiposity, and the duration of the fast. An early event in starvation was a decline in muscle protein synthesis. This occurred in all groups, albeit this reduction occurred more slowly in the older rats. A later response to starvation was an increase in muscle proteolysis. This occurred between 2 and 5 days in the 8-wk-old rats. In 16-wk-old rats it did not occur until between 5-10 days, and it was preceded by a period of decreased proteolysis. In 16-wk-old obese rats, a decrease in proteolysis persisted for upwards of 10 days and the secondary increase was not noted during the period of study. The ability of older and more obese rats to conserve body protein during starvation is due, in part, to a curtailment of muscle proteolysis. This adaptation seems to correlate with the availability of lipid fuels.