Endotoxemia reduces skeletal muscle protein synthesis in neonates.
Endotoxemia reduces skeletal muscle protein synthesis in neonates.
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DOI：
10.1152/ajpendo.00220.2002
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发表时间：
2002-11
期刊：
影响因子：
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通讯作者：
R. Orellana;P. M. O'Connor;Hanh V. Nguyen;Jill A. Bush;A. Suryawan;M. Thivierge;M. Fiorotto;T. Davis
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文献类型：
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作者：
R. Orellana;P. M. O'Connor;Hanh V. Nguyen;Jill A. Bush;A. Suryawan;M. Thivierge;M. Fiorotto;T. Davis
在骨骼肌中的蛋白质合成减少多达50%，早在4小时后，成人败血症的挑战。然而，败血症对肌肉蛋白质合成的影响尚未确定在新生儿，一个高度合成代谢的人群，其肌肉蛋白质合成率升高，独特的胰岛素和氨基酸刺激敏感。新生仔猪（n = 10/组）用内毒素[脂多糖（LPS），0和10 μ g. kg（-1）。h（-1）]。通过输注葡萄糖和平衡氨基酸混合物将血浆氨基酸和葡萄糖浓度保持在进食水平。蛋白质合成率分数通过使用[（3）H]苯丙氨酸的泛液剂量来确定。LPS输注产生败血症样状态，如体温、心率和血浆肿瘤坏死因子-α、白细胞介素-1、皮质醇和乳酸浓度的早期和持续升高所示。血浆胰岛素水平增加，而葡萄糖和氨基酸减少，表明没有胰岛素抵抗。LPS显著降低背最长肌和腓肠肌的蛋白质合成仅分别为11%和15%，但对咬肌和心肌无显著影响。LPS增加肝脏（22%）、脾脏（28%）、肾脏（53%）、空肠（19%）、隔膜（21%）、肺（50%）和皮肤（13%）中的蛋白质合成，但不增加胃、胰腺或脑中的蛋白质合成。这些发现表明，当底物供应维持，骨骼肌蛋白质合成在新生儿与成人相比，是相对抵抗败血症的分解代谢作用。
Protein synthesis in skeletal muscle is reduced by as much as 50% as early as 4 h after a septic challenge in adults. However, the effect of sepsis on muscle protein synthesis has not been determined in neonates, a highly anabolic population whose muscle protein synthesis rates are elevated and uniquely sensitive to insulin and amino acid stimulation. Neonatal piglets (n = 10/group) were infused for 8 h with endotoxin [lipopolysaccharide (LPS), 0 and 10 microg. kg(-1). h(-1)]. Plasma amino acid and glucose concentrations were kept at the fed level by infusion of dextrose and a balanced amino acid mixture. Fractional protein synthesis rates were determined by use of a flooding dose of [(3)H]phenylalanine. LPS infusion produced a septic-like state, as indicated by an early and sustained elevation in body temperature, heart rate, and plasma tumor necrosis factor-alpha, interleukin-1, cortisol, and lactate concentrations. Plasma levels of insulin increased, whereas glucose and amino acids decreased, suggesting the absence of insulin resistance. LPS significantly reduced protein synthesis in longissimus dorsi muscle by only 11% and in gastrocnemius by only 15%, but it had no significant effect in masseter and cardiac muscles. LPS increased protein synthesis in the liver (22%), spleen (28%), kidney (53%), jejunum (19%), diaphragm (21%), lung (50%), and skin (13%), but not in the stomach, pancreas, or brain. These findings suggest that, when substrate supply is maintained, skeletal muscle protein synthesis in neonates compared with adults is relatively resistant to the catabolic effects of sepsis.