Effect of insulin on protein synthesis in skeletal muscle of an isolated perfused preparation of rat hemicorpus.
Effect of insulin on protein synthesis in skeletal muscle of an isolated perfused preparation of rat hemicorpus.
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胰岛素对大鼠半体分离灌注制剂骨骼肌蛋白质合成的影响。
DOI：
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发表时间：
1972
影响因子：
11.1
通讯作者：
H. E. Morgan
中科院分区：
文献类型：
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作者：
L. Jefferson;J. O. Koehler;H. E. Morgan
为研究大鼠骨骼肌代谢，建立了一种大鼠双侧大脑半球体外灌流方法。该制剂在灌流过程中是稳定的，通过维持ATP浓度、灌流压力和耗氧量长达90分钟来表明。灌流的半脑为研究骨骼肌的蛋白质合成提供了以下优点：(A)激素和底物通过完整的毛细血管床到达肌细胞，以及(B)该制剂包括腰大肌，其大小足以测量蛋白质合成途径的中间产物，并且易于均质以制备核糖体和核糖体亚单位。与单独使用含有葡萄糖和胰岛素的缓冲液灌流相比，用含有葡萄糖和胰岛素的缓冲液灌流禁食大鼠的腰大肌，可以降低核糖体亚基的浓度，增加苯丙氨酸的掺入。此外，该激素增加了灌流液中葡萄糖的摄取，并抑制了制剂中游离脂肪酸的释放。当肌肉灌流含有葡萄糖和棕榈酸的缓冲液时，核糖体亚基的浓度和苯丙氨酸的掺入没有变化。由于已知脂肪酸可以刺激心肌中蛋白质的合成，这些结果表明，在禁食期间或糖尿病动物体内，通过增加血浆脂肪酸浓度，可以保持心脏中蛋白质合成的速率，而不是骨骼肌中蛋白质合成的速率。
A method for perfusion in vitro of a preparation of rat hemicorpus was developed for study of the metabolism of skeletal muscle. The preparation was stable during perfusion, as indicated by maintenance of ATP concentration, perfusion pressure, and oxygen consumption for up to 90 min. The perfused hemicorpus provided the following advantages for study of protein synthesis in skeletal muscle: (a) hormones and substrates reached the muscle cells through an intact capillary bed, and (b) the preparation included the psoas muscle, which was sufficiently large to allow measurements of intermediates in the pathway of protein synthesis and was readily homogenized for preparation of ribosomes and ribosomal subunits. Perfusion of psoas muscle from fasted rats with buffer containing glucose and insulin reduced the concentration of ribosomal subunits and increased phenylalanine incorporation as compared to perfusion with buffer containing glucose alone. In addition, the hormone increased glucose uptake from the perfusate and inhibited release of free fatty acids from the preparation. When the muscle was perfused with buffer that contained glucose and palmitate, the concentration of ribosomal subunits and phenylalanine incorporation were unchanged. Since fatty acid is known to stimulate protein synthesis in heart muscle, these results indicated that rates of protein synthesis in heart, but not in skeletal, muscle would be maintained during fasting or in diabetic animals by increased plasma concentration of fatty acid.