Comparison of different techniques for estimating rates of protein synthesis in vivo in healthy and bacteraemic rats.
Comparison of different techniques for estimating rates of protein synthesis in vivo in healthy and bacteraemic rats.
复制标题
评估健康和菌血症大鼠体内蛋白质合成速率的不同技术的比较。
DOI：
10.1042/bj2260037
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Moldawer,LL
中科院分区：
文献类型：
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作者：
Pomposelli,JJ;Palombo,JD;Hamawy,KJ;Bistrian,BR;Blackburn,GL;Moldawer,LL
先前的研究报道，在测定大鼠快速翻转组织中的蛋白质合成速率时，使用全剂量放射性标记氨基酸比持续注入示踪剂更精确。然而，在可比条件下对不同方法进行比较的直接调查却很少。最初，12只健康的雄性Sprague-Dawley大鼠，体重约为。随机分为两组，每100 g体体重静脉注射100 μ mol l -亮氨酸（含30 μ ci [1-14C]亮氨酸），或连续2小时滴注[14C]亮氨酸。在第二阶段的实验中，另外12只大鼠静脉注射1 × 10(8)个铜绿假单胞菌集落形成单位，16小时后随机接受上述两种输注中的一种。测定肝脏、直肌和全身的总蛋白质合成和部分蛋白质合成率。菌血症大鼠肝脏、肌肉和全身的合成率明显高于健康大鼠。与使用直接测量各自组织的酸溶性部分的连续输注方法相比，洪水剂量方法对肝脏、骨骼肌和全身蛋白质合成的估计要高得多。基于血浆富集和随机模型的全身蛋白质合成的间接估计给出了最低值。
Previous studies have reported that use of a flooding dose of radiolabelled amino acid is a more precise technique than the constant infusion of tracer quantities for determining rates of protein synthesis in rapidly turning-over tissues in the rat. However, there has been little direct investigation comparing different methods under comparable conditions. Initially, 12 healthy male Sprague-Dawley rats, weighing approx. 100 g, were randomized to receive either a bolus intravenous injection of 100 mumol of L-leucine (containing 30 microCi of [1-14C]leucine)/100 g body wt., or a continuous 2 h tracer infusion of [14C]leucine. In the second phase of the experiment, 12 additional rats were intravenously injected with 1 × 10(8) colony-forming units of Pseudomonas aeruginosa and 16 h later randomized to receive one of two infusions described above. Total protein synthesis as well as fractional synthesis rates were determined in liver, rectus muscle and whole body. Synthesis rates measured in liver, muscle and whole body were significantly higher in bacteraemic rats than in healthy rats. The flooding-dose methodology gave significantly higher estimates of protein synthesis in the liver, skeletal muscle and whole body than did the continuous-infusion method using direct measurement of the acid-soluble fraction from the respective tissue. Indirect estimates of whole-body protein synthesis based on plasma enrichments and stochastic modelling gave the lowest values.