THE EFFECTS OF FASTING OR HYPOXIA ON RATES OF PROTEIN-SYNTHESIS INVIVO IN SUBCELLULAR-FRACTIONS OF RAT-HEART AND GASTROCNEMIUS-MUSCLE
THE EFFECTS OF FASTING OR HYPOXIA ON RATES OF PROTEIN-SYNTHESIS INVIVO IN SUBCELLULAR-FRACTIONS OF RAT-HEART AND GASTROCNEMIUS-MUSCLE
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DOI：
10.1042/bj2570519
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发表时间：
1989-01-15
影响因子：
4.1
通讯作者：
SUGDEN, PH
中科院分区：
文献类型：
--
作者：
PREEDY, VR;SUGDEN, PH
我们测量的蛋白质合成率在体内的亚细胞组分（可溶性，肌原纤维和基质组分）的心脏和腓肠肌大鼠禁食后或缺氧条件下（即大气中含有5%或10%O2）。已知这种干预在某些情况下抑制蛋白质合成。分离后的组织蛋白回收率为80- 100%。两种肌肉中可溶性和基质部分中存在的蛋白质比例不同。在肌原纤维和基质组分的蛋白质合成率低于总混合组织蛋白质，而可溶性蛋白质的速率更大。禁食和中度缺氧（10%O2 24小时）抑制腓肠肌蛋白质合成。在这个组织中，肌原纤维部分的合成显然是最敏感的抑制，这导致了一些显着增加的可溶性部分/肌原纤维部分蛋白质合成速率比。在心脏，禁食抑制蛋白质合成，但中度缺氧（10%O2 24小时）没有。心肌肌原纤维部分的蛋白质合成率再次比其他部分的速率对禁食更敏感，但不如腓肠肌敏感。在严重缺氧条件下（5%O2为1或2小时），蛋白质的合成减少在两个组织中的所有部分。这些结果表明，在这些相对粗糙的亚细胞组分的蛋白质合成速率不同。
We measured rates of protein synthesis in vivo in subcellular fractions (soluble, myofibrillar and stromal fractions) of the heart and the gastrocnemius from rats after fasting or under hypoxic conditions (i.e. atmospheres containing 5% or 10% O2). Such interventions are known to inhibit protein synthesis under some circumstances. The recovery of tissue protein after fractionation was 80-100%. The proportions of protein present in the soluble and stromal fractions were different in the two muscles. The rates of protein synthesis in the myofibrillar and stromal fractions were less than those for total mixed tissue protein, whereas the rate for soluble protein was greater. Both fasting and moderate hypoxia (10% O2 for 24 h) inhibited protein synthesis in the gastrocnemius. In this tissue, the synthesis of the myofibrillar fraction was apparently the most sensitive to inhibition, and this resulted in some significant increases in the soluble-fraction/myofibrillar-fraction protein-synthesis rate ratios. In the heart, fasting inhibited protein synthesis, but moderate hypoxia (10% O2 for 24 h) did not. The rate of protein synthesis in the cardiac myofibrillar fraction was again more sensitive to fasting than were the rates in the other fractions, but it was not as sensitive as that in the gastrocnemius. Under severely hypoxic conditions (5% O2 for 1 or 2 h), protein synthesis was decreased in all fractions in both tissues. These results suggest that the rates of protein synthesis in these relatively crude subcellular fractions vary.